ZOOM LENS, CAMERA MODULE, AND MOBILE TERMINAL

TECHNICAL FIELD

The embodiments relate to the field of terminal technologies, a zoom lens, a camera module, and a mobile terminal.

BACKGROUND

With popularization and development of smartphones, mobile phone photographing becomes a photographing manner commonly used by people, and requirements for mobile phone photographing technologies are increasingly high, for example, a wider zoom range, higher resolution, and higher imaging quality.

To obtain a wider zoom range, a “jump-type” zoom adjustment manner is generally used for high-magnification optical zoom of a lens of a mobile phone in the market. For example, a plurality of lenses with different focal lengths are mounted, and cooperate with algorithm-based digital zoom, to implement hybrid optical zoom. However, this zoom manner cannot implement a real continuous zoom. In a zoom process of the mobile phone, imaging definition is poor within a focal length range in which focal length ranges of the plurality of lenses are discontinuous, and photographing definition is lower than the real continuous zoom. Therefore, photographing quality of the zoom lens is affected.

SUMMARY

The embodiments may provide a zoom lens, a camera module, and a mobile terminal, to improve photographing quality of the zoom lens.

According to a first aspect, a zoom lens is provided. The zoom lens is used in a mobile terminal such as a mobile phone or a tablet computer. The zoom lens includes a plurality of lens groups. These lens groups include a first lens group, a second lens group, and a third lens group that are arranged along an object side to an image side. The first lens group is a lens group with negative focal power, the second lens group is a lens group with positive focal power, and the third lens group is a lens group with negative focal power. In the foregoing lens groups, the first lens group is a fixed lens group, and the second lens group and the third lens group are configured to move along an optical axis to adjust a focal length when the zoom lens zooms. The second lens group is a zoom lens group and slides along the optical axis on an image side of the first lens group. The third lens group is a compensation lens group and slides along the optical axis on an image side of the second lens group. When the zoom lens zooms from a wide-angle state to a telephoto state, both the second lens group and the third lens group move towards the object side. In addition, a distance between the third lens group and the second lens group first decreases and then increases. This can implement continuous zoom of the zoom lens and improve photographing quality of the zoom lens.

In an implementation, to ensure that the zoom lens has a good continuous zoom capability, a total quantity N of lenses in the first lens group, the second lens group, and the third lens group meets:

7≤N≤11.

In an implementation, to enable the zoom lens to have good imaging quality, lenses included in the zoom lens meet:

N≤a quantity of aspheric surfaces≤2N, where the quantity of aspheric surfaces is a quantity of aspheric surfaces of all lenses included in the zoom lens, to improve imaging quality.

In addition to the foregoing form of three lens groups, a form of four lens groups may alternatively be used. For example, the zoom lens may further include a fourth lens group located on an image side of the third lens group. The fourth lens group is a lens group with positive focal power, and the fourth lens group is a fixed lens group. This can further improve imaging definition of the zoom lens and improve photographing quality.

In an implementation, to ensure that the zoom lens has a good continuous zoom capability, a total quantity N of lenses in the first lens group, the second lens group, the third lens group, and the fourth lens group meets:

7≤N≤13.

Regardless of a zoom lens having three lens groups or a zoom lens having four lens groups, the following limitation is optional.

In an implementation, to enable the zoom lens to have good imaging quality, lenses included in the zoom lens meet:

N≤a quantity of aspheric surfaces≤2N, where the quantity of aspheric surfaces is a quantity of aspheric surfaces of all lenses included in the zoom lens, to improve imaging quality.

In an implementation, to ensure that the zoom lens has a good continuous zoom capability, a focal length f1 of the first lens group and a focal length ft at a telephoto end of the zoom lens meet 0.2≤|f1/ft|≤0.9.

A focal length f2 of the second lens group and the focal length ft meet 0.10≤|f2/ft|≤0.6.

A focal length f3 of the third lens group and the focal length ft meet 0.10≤|f3/ft|≤0.7.

In an implementation, the first lens group to the third lens group may be combined in different manners. For example:

Sequentially arranged from the object side to the image side: the first lens group G1 with negative focal power, where a ratio of the focal length f1 of the first lens group G1 to the focal length ft at the telephoto end of the zoom lens is |f1/ft|=0.579; the second lens group G2 with positive focal power, where a ratio of the focal length f2 of the second lens group G2 to the focal length ft at the telephoto end of the zoom lens is |f2/ft|=0.293; and the third lens group G3 with negative focal power, where a ratio of the focal length f3 of the third lens group G3 to the focal length ft at the telephoto end of the zoom lens is |f3/ft|=0.308.

Sequentially arranged from the object side to the image side: the first lens group G1 with negative focal power, where a ratio of the focal length f1 of the first lens group G1 to the focal length ft at the telephoto end of the zoom lens is |f1/ft|=0.573; the second lens group G2 with positive focal power, where a ratio of the focal length f2 of the second lens group G2 to the focal length ft at the telephoto end of the zoom lens is |f2/ft|=0.282; and the third lens group G3 with negative focal power, where a ratio of the focal length f3 of the third lens group G3 to the focal length ft at the telephoto end of the zoom lens is |f3/ft|=0.147.

Sequentially arranged from the object side to the image side: the first lens group G1 with negative focal power, where the ratio of the focal length f1 of the first lens group G1 to the focal length ft at the telephoto end of the zoom lens is |f1/ft|=0.605; the second lens group G2 with positive focal power, where the ratio of the focal length f2 of the second lens group G2 to the focal length ft at the telephoto end of the zoom lens is |f2/ft|=0.283; and the third lens group G3 with negative focal power, where the ratio of the focal length f3 of the third lens group G3 to the focal length ft at the telephoto end of the zoom lens is |f3/ft|=0.298.

Sequentially arranged from the object side to the image side: the first lens group G1 with negative focal power, where the ratio of the focal length f1 of the first lens group G1 to the focal length ft (namely, a focal length when the zoom lens is in the telephoto state) at the telephoto end of the zoom lens is |f1/ft|=0.796; the second lens group G2 with positive focal power, where the ratio of the focal length f2 of the second lens group G2 to the focal length ft at the telephoto end of the zoom lens is |f2/ft|=0.309; and the third lens group G3 with negative focal power, where the ratio of the focal length f3 of the third lens group G3 to the focal length ft at the telephoto end of the zoom lens is |f3/ft|=0.597.

Sequentially arranged from the object side to the image side: the first lens group G1 with negative focal power, where the ratio of the focal length f1 of the first lens group G1 to the focal length ft at the telephoto end of the zoom lens is |f1/ft|=0.556; the second lens group G2 with positive focal power, where the ratio of the focal length f2 of the second lens group G2 to the focal length ft at the telephoto end of the zoom lens is |f2/ft|=0.241; the third lens group G3 with negative focal power, where the ratio of the focal length f3 of the third lens group G3 to the focal length ft at the telephoto end of the zoom lens is |f3/ft|=0.211; and the fourth lens group G4 with positive focal power, where a ratio of a focal length f4 of the fourth lens group G4 to the focal length ft at the telephoto end of the zoom lens is |f4/ft|=0.286.

Sequentially arranged from the object side to the image side: the first lens group G1 with negative focal power, where the ratio of the focal length f1 of the first lens group G1 to the focal length ft at the telephoto end of the zoom lens is |f1/ft|=0.579; the second lens group G2 with positive focal power, where the ratio of the focal length f2 of the second lens group G2 to the focal length ft at the telephoto end of the zoom lens is |f2/ft|=0.260; the third lens group G3 with negative focal power, where the ratio of the focal length f3 of the third lens group G3 to the focal length ft at the telephoto end of the zoom lens is |f3/ft|=0.205; and the fourth lens group G4 with positive focal power, where the ratio of the focal length f4 of the fourth lens group G4 to the focal length ft at the telephoto end of the zoom lens is |f4/ft|=0.307.

Sequentially arranged from the object side to the image side: the first lens group G1 with negative focal power, where the ratio of the focal length f1 of the first lens group G1 to the focal length ft at the telephoto end of the zoom lens is |f1/ft|=0.634; the second lens group G2 with positive focal power, where the ratio of the focal length f2 of the second lens group G2 to the focal length ft at the telephoto end of the zoom lens is |f2/ft|=0.228; the third lens group G3 with negative focal power, where the ratio of the focal length f3 of the third lens group G3 to the focal length ft at the telephoto end of the zoom lens is |f3/ft|=0.171; and the fourth lens group G4 with positive focal power, where the ratio of the focal length f4 of the fourth lens group G4 to the focal length ft at the telephoto end of the zoom lens is |f4/ft|=0.570.

Sequentially arranged from the object side to the image side: the first lens group G1 with negative focal power, where the ratio of the focal length f1 of the first lens group G1 to the focal length ft at the telephoto end of the zoom lens is |f1/ft|=0.447; the second lens group G2 with positive focal power, where the ratio of the focal length f2 of the second lens group G2 to the focal length ft at the telephoto end of the zoom lens is |f2/ft|=0.217; the third lens group G3 with negative focal power, where the ratio of the focal length f3 of the third lens group G3 to the focal length ft at the telephoto end of the zoom lens is |f3/ft|=0.202; and the fourth lens group G4 with positive focal power, where the ratio of the focal length f4 of the fourth lens group G4 to the focal length ft at the telephoto end of the zoom lens is |f4/ft|=0.881.

Sequentially arranged from the object side to the image side: the first lens group G1 with negative focal power, where the ratio of the focal length f1 of the first lens group G1 to the focal length ft at the telephoto end of the zoom lens is |f1/ft|=0.71; the second lens group G2 with positive focal power, where the ratio of the focal length f2 of the second lens group G2 to the focal length ft at the telephoto end of the zoom lens is |f2/ft|=0.23; the third lens group G3 with negative focal power, where the ratio of the focal length f3 of the third lens group G3 to the focal length ft at the telephoto end of the zoom lens is |f3/ft|=0.335; and the fourth lens group G4 with positive focal power, where the ratio of the focal length f4 of the fourth lens group G4 to the focal length ft at the telephoto end of the zoom lens is |f4/ft|=0.384.

In an implementation, a movement stroke L1 of the second lens group along the optical axis and a total length TTL of the zoom lens from a surface closest to the object side to an imaging plane meet 0.12≤|L1/TTL|≤0.35.

In an implementation, a movement stroke L2 of the third lens group along the optical axis and the total length TTL of the zoom lens from the surface closest to the object side to the imaging plane meet 0.08≤|L2/TTL|≤0.3.

In an implementation, the second lens group includes at least one lens with negative focal power, to correct aberration.

In an implementation, the zoom lens further includes a prism or a mirror reflector. The prism or the mirror reflector is located on an object side of the first lens group. The prism or the mirror reflector is configured to deflect a light ray to the first lens group. This can implement periscope photographing, to more flexibly design an installation position and an installation direction of the zoom lens.

In an implementation, a lens of each lens group in the zoom lens has a cut for reducing a height of the lens. This can reduce space occupied by the zoom lens and increase luminous flux.

In an implementation, a height h in a vertical direction of a lens included in each lens group in the zoom lens meets:

4 mm≤h≤6 mm, to fit installation space of a mobile terminal such as a mobile phone.

In an implementation, to ensure the luminous flux and the space occupied, a maximum aperture diameter d of a lens included in each lens group in the zoom lens meets:

4 mm≤d≤12 mm.

In an implementation, a difference between a chief ray angle when the zoom lens is in a wide-angle state and a chief ray angle when the zoom lens is in a telephoto state is less than or equal to 6°.

In an implementation, an object distance of the zoom lens ranges from infinity to 40 mm.

In an implementation, a range of a ratio of a half-image height IMH to an effective focal length ft at the telephoto end of the zoom lens meets 0.02≤|IMH/ft|≤0.20.

In an embodiment, the effective focal length ft at the telephoto end and an effective focal length fw at a wide-angle end of the zoom lens meet 1≤|ft/fw|≤3.7.

According to a second aspect, a camera module is provided. The camera module includes a camera chip and the zoom lens according to any one of the first aspect and the implementations of the first aspect. A light ray passes through the zoom lens and strikes the camera chip. A second lens group is configured to implement zoom, and a third lens group is configured to implement focusing through focal length compensation. This can achieve continuous zoom and improve photographing quality of the zoom lens.

According to a third aspect, a mobile terminal is provided. The mobile terminal may be a mobile phone, a tablet computer, or the like. The mobile terminal includes a housing, and the zoom lens according to any one of the first aspect and the implementations of the first aspect and disposed in the housing according to any one of the foregoing implementations. A second lens group is configured to implement zoom, and a third lens group is configured to implement focusing through focal length compensation. This can achieve continuous zoom and improve photographing quality of the zoom lens.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of an example of a mobile terminal in which a zoom lens is used according to an embodiment;

FIG. 2 is an example of a zoom lens having three lens groups according to an embodiment;

FIG. 3 is a diagram of an example of a structure of a lens in a first lens group in FIG. 2;

FIG. 4 is an example of a first zoom lens;

FIG. 5 is a zoom process of the zoom lens shown in FIG. 4;

FIG. 6a shows axial aberration curves of the zoom lens shown in FIG. 4 in a wide-angle state W;

FIG. 6b shows axial aberration curves of the zoom lens shown in FIG. 4 in a first intermediate focal length state M1;

FIG. 6c shows axial aberration curves of the zoom lens shown in FIG. 4 in a second intermediate focal length state M2;

FIG. 6d shows axial aberration curves of the zoom lens shown in FIG. 4 in a telephoto state T;

FIG. 7a shows lateral chromatic aberration curves of the zoom lens shown in FIG. 4 in the wide-angle state W;

FIG. 7b shows lateral chromatic aberration curves of the zoom lens shown in FIG. 4 in the first intermediate focal length state M1;

FIG. 7c shows lateral chromatic aberration curves of the zoom lens shown in FIG. 4 in the second intermediate focal length state M2;

FIG. 7d shows lateral chromatic aberration curves of the zoom lens shown in FIG. 4 in the telephoto state T;

FIG. 8a shows optical distortion curves of the zoom lens shown in FIG. 4 in the wide-angle state W;

FIG. 8b shows optical distortion percentages of the zoom lens shown in FIG. 4 in the wide-angle state W;

FIG. 9a shows optical distortion curves of the zoom lens shown in FIG. 4 in the first intermediate focal length state M1;

FIG. 9b shows optical distortion percentages of the zoom lens shown in FIG. 4 in the first intermediate focal length state M1;

FIG. 10a shows optical distortion curves of the zoom lens shown in FIG. 4 in the second intermediate focal length state M2;

FIG. 10b shows optical distortion percentages of the zoom lens shown in FIG. 4 in the second intermediate focal length state M2;

FIG. 11a shows optical distortion curves of the zoom lens shown in FIG. 4 in the telephoto state T;

FIG. 11b shows optical distortion percentages of the zoom lens shown in FIG. 4 in the telephoto state T;

FIG. 12 is an example of a second zoom lens;

FIG. 13 is a zoom process of the zoom lens shown in FIG. 12;

FIG. 14a shows axial aberration curves of the zoom lens shown in FIG. 12 in a wide-angle state W;

FIG. 14b shows axial aberration curves of the zoom lens shown in FIG. 12 in a first intermediate focal length state M1;

FIG. 14c shows axial aberration curves of the zoom lens shown in FIG. 12 in a second intermediate focal length state M2;

FIG. 14d shows axial aberration curves of the zoom lens shown in FIG. 12 in a telephoto state T;

FIG. 15a shows lateral chromatic aberration curves of the zoom lens shown in FIG. 12 in the wide-angle state W;

FIG. 15b shows lateral chromatic aberration curves of the zoom lens shown in FIG. 12 in the first intermediate focal length state M1;

FIG. 15c shows lateral chromatic aberration curves of the zoom lens shown in FIG. 12 in the second intermediate focal length state M2;

FIG. 15d shows lateral chromatic aberration curves of the zoom lens shown in FIG. 12 in the telephoto state T;

FIG. 16a shows optical distortion curves of the zoom lens shown in FIG. 12 in the wide-angle state W;

FIG. 16b shows optical distortion percentages of the zoom lens shown in FIG. 12 in the wide-angle state W;

FIG. 17a shows optical distortion curves of the zoom lens shown in FIG. 12 in the first intermediate focal length state M1;

FIG. 17b shows optical distortion percentages of the zoom lens shown in FIG. 12 in the first intermediate focal length state M1;

FIG. 18a shows optical distortion curves of the zoom lens shown in FIG. 12 in the second intermediate focal length state M2;

FIG. 18b shows optical distortion percentages of the zoom lens shown in FIG. 12 in the second intermediate focal length state M2;

FIG. 19a shows optical distortion curves of the zoom lens shown in FIG. 12 in the telephoto state T;

FIG. 19b shows optical distortion percentages of the zoom lens shown in FIG. 12 in the telephoto state T;

FIG. 20 is an example of a third zoom lens;

FIG. 21 is a zoom process of the zoom lens shown in FIG. 20;

FIG. 22a shows axial aberration curves of the zoom lens shown in FIG. 20 in a wide-angle state W;

FIG. 22b shows axial aberration curves of the zoom lens shown in FIG. 20 in a first intermediate focal length state M1;

FIG. 22c shows axial aberration curves of the zoom lens shown in FIG. 20 in a second intermediate focal length state M2;

FIG. 22d shows axial aberration curves of the zoom lens shown in FIG. 20 in a telephoto state T;

FIG. 23a shows lateral chromatic aberration curves of the zoom lens shown in FIG. 20 in the wide-angle state W;

FIG. 23b shows lateral chromatic aberration curves of the zoom lens shown in FIG. 20 in the first intermediate focal length state M1;

FIG. 23c shows lateral chromatic aberration curves of the zoom lens shown in FIG. 20 in the second intermediate focal length state M2;

FIG. 23d shows lateral chromatic aberration curves of the zoom lens shown in FIG. 20 in the telephoto state T;

FIG. 24a shows optical distortion curves of the zoom lens shown in FIG. 20 in the wide-angle state W;

FIG. 24b shows optical distortion percentages of the zoom lens shown in FIG. 20 in the wide-angle state W;

FIG. 25a shows optical distortion curves of the zoom lens shown in FIG. 20 in the first intermediate focal length state M1;

FIG. 25b shows optical distortion percentages of the zoom lens shown in FIG. 20 in the first intermediate focal length state M1;

FIG. 26a shows optical distortion curves of the zoom lens shown in FIG. 20 in the second intermediate focal length state M2;

FIG. 26b shows optical distortion percentages of the zoom lens shown in FIG. 20 in the second intermediate focal length state M2;

FIG. 27a shows optical distortion curves of the zoom lens shown in FIG. 20 in the telephoto state T;

FIG. 27b shows optical distortion percentages of the zoom lens shown in FIG. 20 in the telephoto state T;

FIG. 28 is an example of a fourth zoom lens;

FIG. 29 is a zoom process of the zoom lens shown in FIG. 28;

FIG. 30a shows axial aberration curves of the zoom lens shown in FIG. 28 in a wide-angle state W;

FIG. 30b shows axial aberration curves of the zoom lens shown in FIG. 28 in an intermediate focal length state M;

FIG. 30c shows axial aberration curves of the zoom lens shown in FIG. 28 in a telephoto state T;

FIG. 31a shows lateral chromatic aberration curves of the zoom lens shown in FIG. 28 in the wide-angle state W;

FIG. 31b shows lateral chromatic aberration curves of the zoom lens shown in FIG. 28 in the intermediate focal length state M;

FIG. 31c shows lateral chromatic aberration curves of the zoom lens shown in FIG. 28 in the telephoto state T;

FIG. 32a shows optical distortion curves of the zoom lens shown in FIG. 28 in the wide-angle state W;

FIG. 32b shows optical distortion percentages of the zoom lens shown in FIG. 28 in the wide-angle state W;

FIG. 33a shows optical distortion curves of the zoom lens shown in FIG. 28 in the intermediate focal length state M;

FIG. 33b shows optical distortion percentages of the zoom lens shown in FIG. 28 in the intermediate focal length state M;

FIG. 34a shows optical distortion curves of the zoom lens shown in FIG. 28 in the telephoto state T;

FIG. 34b shows optical distortion percentages of the zoom lens shown in FIG. 28 in the telephoto state T;

FIG. 35 is an example of a fifth zoom lens;

FIG. 36 is a zoom process of the zoom lens shown in FIG. 35;

FIG. 37a shows axial aberration curves of the zoom lens shown in FIG. 35 in a wide-angle state W;

FIG. 37b shows axial aberration curves of the zoom lens shown in FIG. 35 in a first intermediate focal length state M1;

FIG. 37c shows axial aberration curves of the zoom lens shown in FIG. 35 in a second intermediate focal length state M2;

FIG. 37d shows axial aberration curves of the zoom lens shown in FIG. 35 in a telephoto state T;

FIG. 38a shows lateral chromatic aberration curves of the zoom lens shown in FIG. 35 in the wide-angle state W;

FIG. 38b shows lateral chromatic aberration curves of the zoom lens shown in FIG. 35 in the first intermediate focal length state M1;

FIG. 38c shows lateral chromatic aberration curves of the zoom lens shown in FIG. 35 in the second intermediate focal length state M2;

FIG. 38d shows lateral chromatic aberration curves of the zoom lens shown in FIG. 35 in the telephoto state T;

FIG. 39a shows optical distortion curves of the zoom lens shown in FIG. 35 in the wide-angle state W;

FIG. 39b shows optical distortion percentages of the zoom lens shown in FIG. 35 in the wide-angle state W;

FIG. 40a shows optical distortion curves of the zoom lens shown in FIG. 35 in the first intermediate focal length state M1;

FIG. 40b shows optical distortion percentages of the zoom lens shown in FIG. 35 in the first intermediate focal length state M1;

FIG. 41a shows optical distortion curves of the zoom lens shown in FIG. 35 in the second intermediate focal length state M2;

FIG. 41b shows optical distortion percentages of the zoom lens shown in FIG. 35 in the second intermediate focal length state M2;

FIG. 42a shows optical distortion curves of the zoom lens shown in FIG. 35 in the telephoto state T;

FIG. 42b shows optical distortion percentages of the zoom lens shown in FIG. 35 in the telephoto state T;

FIG. 43 is an example of a sixth zoom lens;

FIG. 44 is a zoom process of the zoom lens shown in FIG. 43;

FIG. 45a shows axial aberration curves of the zoom lens shown in FIG. 43 in a wide-angle state W;

FIG. 45b shows axial aberration curves of the zoom lens shown in FIG. 43 in a first intermediate focal length state M1;

FIG. 45c shows axial aberration curves of the zoom lens shown in FIG. 43 in a second intermediate focal length state M2;

FIG. 45d shows axial aberration curves of the zoom lens shown in FIG. 43 in a telephoto state T;

FIG. 46a shows lateral chromatic aberration curves of the zoom lens shown in FIG. 43 in the wide-angle state W;

FIG. 46b shows lateral chromatic aberration curves of the zoom lens shown in FIG. 43 in the first intermediate focal length state M1;

FIG. 46c shows lateral chromatic aberration curves of the zoom lens shown in FIG. 43 in the second intermediate focal length state M2;

FIG. 46d shows lateral chromatic aberration curves of the zoom lens shown in FIG. 43 in the telephoto state T;

FIG. 47a shows optical distortion curves of the zoom lens shown in FIG. 43 in the wide-angle state W;

FIG. 47b shows optical distortion percentages of the zoom lens shown in FIG. 43 in the wide-angle state W;

FIG. 48a shows optical distortion curves of the zoom lens shown in FIG. 43 in the first intermediate focal length state M1;

FIG. 48b shows optical distortion percentages of the zoom lens shown in FIG. 43 in the first intermediate focal length state M1;

FIG. 49a shows optical distortion curves of the zoom lens shown in FIG. 43 in the second intermediate focal length state M2;

FIG. 49b shows optical distortion percentages of the zoom lens shown in FIG. 43 in the second intermediate focal length state M2;

FIG. 50a shows optical distortion curves of the zoom lens shown in FIG. 43 in the telephoto state T;

FIG. 50b shows optical distortion percentages of the zoom lens shown in FIG. 43 in the telephoto state T;

FIG. 51 is an example of a seventh zoom lens;

FIG. 52 is a zoom process of the zoom lens shown in FIG. 51;

FIG. 53a shows axial aberration curves of the zoom lens shown in FIG. 51 in a wide-angle state W;

FIG. 53b shows axial aberration curves of the zoom lens shown in FIG. 51 in a first intermediate focal length state M1;

FIG. 53c shows axial aberration curves of the zoom lens shown in FIG. 51 in a second intermediate focal length state M2;

FIG. 53d shows axial aberration curves of the zoom lens shown in FIG. 51 in a telephoto state T;

FIG. 54a shows lateral chromatic aberration curves of the zoom lens shown in FIG. 51 in the wide-angle state W;

FIG. 54b shows lateral chromatic aberration curves of the zoom lens shown in FIG. 51 in the first intermediate focal length state M1;

FIG. 54c shows lateral chromatic aberration curves of the zoom lens shown in FIG. 51 in the second intermediate focal length state M2;

FIG. 54d shows lateral chromatic aberration curves of the zoom lens shown in FIG. 51 in the telephoto state T;

FIG. 55a shows optical distortion curves of the zoom lens shown in FIG. 51 in the wide-angle state W;

FIG. 55b shows optical distortion percentages of the zoom lens shown in FIG. 51 in the wide-angle state W;

FIG. 56a shows optical distortion curves of the zoom lens shown in FIG. 51 in the first intermediate focal length state M1;

FIG. 56b shows optical distortion percentages of the zoom lens shown in FIG. 51 in the first intermediate focal length state M1;

FIG. 57a shows optical distortion curves of the zoom lens shown in FIG. 51 in the second intermediate focal length state M2;

FIG. 57b shows optical distortion percentages of the zoom lens shown in FIG. 51 in the second intermediate focal length state M2;

FIG. 58a shows optical distortion curves of the zoom lens shown in FIG. 51 in the telephoto state T;

FIG. 58b shows optical distortion percentages of the zoom lens shown in FIG. 51 in the telephoto state T;

FIG. 59 is an example of an eighth zoom lens;

FIG. 60 is a zoom process of the zoom lens shown in FIG. 59;

FIG. 61a shows axial aberration curves of the zoom lens shown in FIG. 59 in a wide-angle state W;

FIG. 61b shows axial aberration curves of the zoom lens shown in FIG. 59 in a first intermediate focal length state M1;

FIG. 61c shows axial aberration curves of the zoom lens shown in FIG. 59 in a second intermediate focal length state M2;

FIG. 61d shows axial aberration curves of the zoom lens shown in FIG. 59 in a telephoto state T;

FIG. 62a shows lateral chromatic aberration curves of the zoom lens shown in FIG. 59 in the wide-angle state W;

FIG. 62b shows lateral chromatic aberration curves of the zoom lens shown in FIG. 59 in the first intermediate focal length state M1;

FIG. 62c shows lateral chromatic aberration curves of the zoom lens shown in FIG. 59 in the second intermediate focal length state M2;

FIG. 62d shows lateral chromatic aberration curves of the zoom lens shown in FIG. 59 in the telephoto state T;

FIG. 63a shows optical distortion curves of the zoom lens shown in FIG. 59 in the wide-angle state W;

FIG. 63b shows optical distortion percentages of the zoom lens shown in FIG. 59 in the wide-angle state W;

FIG. 64a shows optical distortion curves of the zoom lens shown in FIG. 59 in the first intermediate focal length state M1;

FIG. 64b shows optical distortion percentages of the zoom lens shown in FIG. 59 in the first intermediate focal length state M1;

FIG. 65a shows optical distortion curves of the zoom lens shown in FIG. 59 in the second intermediate focal length state M2;

FIG. 65b shows optical distortion percentages of the zoom lens shown in FIG. 59 in the second intermediate focal length state M2;

FIG. 66a shows optical distortion curves of the zoom lens shown in FIG. 59 in the telephoto state T;

FIG. 66b shows optical distortion percentages of the zoom lens shown in FIG. 59 in the telephoto state T;

FIG. 67 is an example of a ninth zoom lens;

FIG. 68 is a zoom process of the zoom lens shown in FIG. 67;

FIG. 69a shows axial aberration curves of the zoom lens shown in FIG. 67 in a wide-angle state W;

FIG. 69b shows axial aberration curves of the zoom lens shown in FIG. 67 in a first intermediate focal length state M1;

FIG. 69c shows axial aberration curves of the zoom lens shown in FIG. 67 in a second intermediate focal length state M2;

FIG. 69d shows axial aberration curves of the zoom lens shown in FIG. 67 in a telephoto state T;

FIG. 70a shows lateral chromatic aberration curves of the zoom lens shown in FIG. 67 in the wide-angle state W;

FIG. 70b shows lateral chromatic aberration curves of the zoom lens shown in FIG. 67 in the first intermediate focal length state M1;

FIG. 70c shows lateral chromatic aberration curves of the zoom lens shown in FIG. 67 in the second intermediate focal length state M2;

FIG. 70d shows lateral chromatic aberration curves of the zoom lens shown in FIG. 67 in the telephoto state T;

FIG. 71a shows optical distortion curves of the zoom lens shown in FIG. 67 in the wide-angle state W;

FIG. 71b shows optical distortion percentages of the zoom lens shown in FIG. 67 in the wide-angle state W;

FIG. 72a shows optical distortion curves of the zoom lens shown in FIG. 67 in the first intermediate focal length state M1;

FIG. 72b shows optical distortion percentages of the zoom lens shown in FIG. 67 in the first intermediate focal length state M1;

FIG. 73a shows optical distortion curves of the zoom lens shown in FIG. 67 in the second intermediate focal length state M2;

FIG. 73b shows optical distortion percentages of the zoom lens shown in FIG. 67 in the second intermediate focal length state M2;

FIG. 74a shows optical distortion curves of the zoom lens shown in FIG. 67 in the telephoto state T;

FIG. 74b shows optical distortion percentages of the zoom lens shown in FIG. 67 in the telephoto state T;

FIG. 75 shows another zoom lens;

FIG. 76 is a schematic diagram of application of the zoom lens shown in FIG. 60 in a mobile phone; and

FIG. 77 shows another zoom lens.

DETAILED DESCRIPTION OF THE EMBODIMENTS

For ease of understanding a zoom lens provided in the embodiments, English abbreviations and related nouns in the embodiments have the following meanings.

A lens with positive focal power has a positive focal length and converges light rays.

A lens with negative focal power has a negative focal length and diverges light rays.

Fixed lens group: In the embodiments, a fixed lens group is a lens group with a fixed position in a zoom lens.

Zoom lens group: In the embodiments, a zoom lens group is a lens group that is in a zoom lens and that adjusts a focal length of the zoom lens by moving.

Compensation lens group: In the embodiments, a compensation lens group is a lens group that moves collaboratively with a zoom lens group and that is used to compensate for a focus adjustment range of the zoom lens group.

An imaging plane is a carrier surface that is located on image sides of all lenses in a zoom lens and that is of an image formed after light successively passes through the lenses in the zoom lens. For a position of the imaging plane, refer to FIG. 2.

F-number: An F-number/aperture is a ratio (a reciprocal of a relative aperture) of a focal length of a zoom lens to an aperture diameter of the zoom lens. A smaller aperture F-number indicates more light passing through the lens per unit time period. A larger aperture F-number indicates a smaller depth of field and blurring of a background of a photo. This effect is similar to that of a long-focus zoom lens.

FOV: field of view.

TTL: A total track length may be a total length from a surface closest to an object side to an imaging plane. TTL is a main factor that forms a camera height.

CRA: chief ray angle.

IMH: image height. A half-image height is a height from an imaging edge to a center of an imaging plane.

To facilitate understanding of the zoom lens provided in the embodiments, an application scenario of the zoom lens provided in the embodiments is first described. The zoom lens provided in the embodiments is used in a camera module of a mobile terminal. The mobile terminal may be a common mobile terminal such as a mobile phone or a tablet computer.

FIG. 1 is a sectional view of the mobile phone. A lens 201 of a camera module 200 is fastened to a housing 100 of the mobile terminal, and a camera chip 202 is fastened in the housing 100. During use, a light ray passes through the lens 201 and strikes the camera chip 202, and the camera chip 202 converts an optical signal into an electrical signal and performs imaging, to implement photographing effect. To obtain a wider zoom range, jump-type digital zoom is generally used in a camera module 200 in a conventional technology. A plurality of (for example, two to three) lenses with different focal lengths are mounted, and cooperate with algorithm-based digital zoom, to implement hybrid optical zoom. However, the jump-type digital zoom is based on a plurality of cameras with different focal lengths, and continuous zoom is implemented through algorithm processing. This is not a real continuous zoom, and imaging definition is poor in some focal length ranges. To resolve the foregoing problem, a zoom lens is provided in the embodiments.

To facilitate understanding of the zoom lens provided in the embodiments, the following describes the zoom lens provided in the embodiments with reference to the accompanying drawings and embodiments.

FIG. 2 is an example of a zoom lens having three lens groups according to an embodiment. The zoom lens includes three lens groups: a first lens group G1, a second lens group G2, and a third lens group G3 that are arranged along an object side to an image side. The first lens group G1 is a lens group with negative focal power, the second lens group G2 is a lens group with positive focal power, and the third lens group G3 is a lens group with negative focal power. A lens group with positive focal power has a positive focal length and converges light rays, and a lens group with negative focal power has a negative focal length and diverges light rays.

In the foregoing three lens groups, the first lens group G1 is a fixed lens group. For example, a position of the first lens group G1 is fixed relative to the housing 100 in FIG. 1, that is, the position of the first lens group G1 is fixed relative to an imaging plane. The second lens group G2 and the third lens group G3 may move along an optical axis of the zoom lens relative to the first lens group G1. The second lens group G2 slides along the optical axis of the zoom lens on an image side of the first lens group G1. The third lens group G3 slides along the optical axis of the zoom lens on an image side of the second lens group G2. The second lens group G2 serves as a zoom lens group to greatly adjust a focal length, to implement zoom. The third lens group G3 serves as a compensation lens group to slightly adjust the focal length, to implement focusing. Therefore, the second lens group G2 has a larger stroke than the third lens group G3.

FIG. 3 shows a lens 10 of the first lens group G1 in FIG. 2, where d is a maximum aperture diameter of the lens 10, h is a height of the lens 10, and the maximum aperture diameter d is a maximum diameter of the lens 10. Two opposite sides (or one side) of the lens 10 have a cut 11, to reduce a height of the lens 10, so that h is less than d. In this embodiment, a lens structure similar to that shown in FIG. 3 is used in each lens in the first lens group G1, the second lens group G2, and the third lens group G3 Luminous flux may be greater than that of a circular lens whose diameter is h, and a size in a height direction may be less than that of a circular lens whose diameter is d. A maximum aperture diameter of a lens in the first lens group G1, the second lens group G2, and the third lens group G3 meets 4 mm≤maximum aperture diameter d≤12 mm A maximum aperture diameter of a lens in the foregoing lens groups may be of a size such as 4 mm, 8 mm, 8.8 mm, 9.6 mm, 9.888 mm, 10 mm, or 12 mm, so that the zoom lens can balance an amount of light passing through the zoom lens and space occupied by the zoom lens. In addition, in the first lens group G1, the second lens group G2, and the third lens group G3, lenses of each lens group have a cut similar to the cut 11 of the lens 10. For example, a height in a vertical direction of each lens meets 4 mm≤height in a vertical direction≤6 mm. For example, the height in the vertical direction may be 4 mm, 5 mm, or 6 mm, to reduce a height of the zoom lens, so that the zoom lens can be used in a scenario with small space, such as a mobile phone.

To facilitate understanding of effect of the zoom lens provided in this embodiment, the following describes imaging effect of the zoom lens in detail.

FIG. 4 is an example of a first zoom lens. The zoom lens sequentially includes the following from an object side to an image side: a first lens group G1 with negative focal power, where a ratio of a focal length f1 of the first lens group G1 to a focal length ft (namely, a focal length when the zoom lens is in a telephoto state) at a telephoto end of the zoom lens is |f1/ft|=0.579; a second lens group G2 with positive focal power, where a ratio of a focal length f2 of the second lens group G2 to the focal length ft at the telephoto end of the zoom lens is |f2/ft|=0.293; and a third lens group G3 with negative focal power, where a ratio of a focal length f3 of the third lens group G3 to the focal length ft at the telephoto end of the zoom lens is |f3/ft|=0.308.

The zoom lens includes eight lenses with focal power and includes 10 aspheric surfaces in total. The first lens group G1 includes two lenses sequentially distributed from the object side to the image side, and the two lenses are with positive and negative focal power respectively. The second lens group G2 sequentially includes four lenses sequentially distributed from the object side to the image side, and the four lenses are with positive, positive, negative, and positive focal power respectively. The third lens group G3 includes two lenses sequentially distributed from the object side to the image side, and the two lenses are with positive and negative focal power respectively. The second lens group G2 includes at least one lens with negative focal power, to eliminate an aberration. In addition, the zoom lens further has a stop (not shown in FIG. 4). The stop is located on an object side of the second lens group G2 but is not limited thereto. Alternatively, the stop may be disposed on an image side or an object side of the first lens group G1 or may be disposed on an image side or an object side of the third lens group G3. A maximum aperture diameter of a lens in the first lens group G1, the second lens group G2, and the third lens group G3 is 9.888 mm.

Subsequently, refer to Table 1a and Table 1b. Table 1a shows a surface curvature, a thickness, a refractive index (nd), and an abbe coefficient (vd) of each lens of the zoom lens shown in FIG. 4 in a wide-angle state. R1 to R16 in a table header on a left column indicate 16 surfaces of the eight lenses from the object side to the image side. For example, R1 indicates a surface on an object side of a first lens from the object side, R2 indicates a surface on an image side of the first lens from the object side, R3 indicates a surface on an object side of a second lens from the object side, R4 indicates a surface on an image side of the second lens from the object side, and so on. In the table header of the top row, R indicates a curvature of a corresponding lens surface. In thickness, d1 to d8 indicate thicknesses of the eight lenses respectively from the object side to the image side, in mm. In addition, a1 to a8 indicate distances between every two adjacent lenses (or between a lens and an imaging plane) respectively from the object side to the image side. For example, a1 indicates a size of a gap between the first lens and the second lens, a2 indicates a size of a gap between the second lens and a third lens, and so on. Finally, a8 indicates a size of a gap between an eighth lens and the imaging plane, in mm. Moreover, n1 to n8 indicate refractive indexes of the eight lenses respectively from the object side to the image side, and v1 to v8 indicate abbe coefficients of the eight lenses respectively from the object side to the image side. Table 1b shows aspheric coefficients of aspheric surfaces of the lenses.

TABLE 1a

R
Thickness
nd
vd

R1
13.412
d1
1.8
n1
1.67
v1
19.2

R2
167.655
a1
1.847

R3
−13.107
d2
0.4
n2
1.90
v2
31.3

R4
20.280
a2
9

R5
6.285
d3
1.285
n3
1.54
v3
56.0

R6
−28.038
a3
1.676

R7
16.951
d4
0.943
n4
1.54
v4
56.0

R8
−14.786
a4
0.080

R9
−37.994
d5
0.400
n5
1.67
v5
19.2

R10
8.983
a5
5.332

R11
8.705
d6
0.821
n6
1.67
v6
19.2

R12
19.433
a6
2.997

R13
−36.499
d7
1.800
n7
1.67
v7
19.2

R14
−6.977
a7
0.410

R15
−4.749
d8
0.400
n8
1.88
v8
19.2

R16
−127.677
a8
0.080

TABLE 1b

Aspheric coefficient

Type
K
A2
A3
A4
A5
A6

R1
Even
0.00E+00
8.84E−05
4.04E−07
2.39E−07
−8.48E−09
3.25E−10

aspheric

R2
Even
0.00E+00
−6.00E−05
1.76E−06
−6.24E−08
1.12E−08
−1.17E−10

aspheric

R5
Even
0.00E+00
−1.97E−04
1.06E−05
−7.24E−07
3.84E−08
4.42E−10

aspheric

R6
Even
0.00E+00
5.22E−04
9.80E−06
−4.02E−07
2.72E−08
−1.76E−10

aspheric

R9
Even
0.00E+00
3.37E−04
1.58E−05
1.68E−06
−3.63E−07
2.71E−09

aspheric

R10
Even
0.00E+00
7.04E−04
5.67E−05
4.003E−06
−2.33E−07
−1.92E−08

aspheric

R11
Even
0.00E+00
−1.61E−03
−7.30E−05
−3.87E−06
1.80E−07
−3.51E−08

aspheric

R12
Even
0.00E+00
−1.53E−03
−9.21E−05
2.92E−07
−3.22E−07
−1.39E−09

aspheric

R13
Even
0.00E+00
1.60E−03
8.05E−06
2.62E−05
−3.31E−06
2.10E−07

aspheric

R14
Even
0.00E+00
7.91E−04
−9.71E−06
2.56E−05
−3.57E−06
2.37E−07

aspheric

In the 10 aspheric surfaces of the zoom lens shown in Table 1b, surface types z of all the even aspheric surfaces may be defined according to, but not limited to, the following aspheric surface formula:

$z = \frac{{cr}^{2}}{1 + \sqrt{1 - {Kc}^{2} r^{2}}} + A_{2} r^{4} + A_{3} r^{6} + A_{4} r^{8} + A_{5} r^{10} + A_{6} r^{12},$

where

z is a vector height of the aspheric surface, r is a radial coordinate of the aspheric surface, c is a spherical curvature of a vertex on the aspheric surface, K is a conic constant, and A2, A3, A4, A5, and A6 are aspheric coefficients.

Because the zoom lens has the 10 aspheric surfaces, the aspheric surfaces may be flexibly designed, and a good aspheric surface type may be designed based on an actual requirement, to improve imaging quality.

A structure of the zoom lens shown in FIG. 4 is used for light to pass through. A ratio |TTL/ft| of a total length TTL of the zoom lens from a surface closest to the object side to the imaging plane to the effective focal length ft at the telephoto end of the zoom lens may reach 0.912. A small total optical length may be used to achieve a long focal length. A ratio |IMH/ft| of a half-image height IMH to the effective focal length ft at the telephoto end of the zoom lens may reach 0.08955.

As shown in FIG. 4, a position of the first lens group G1 is fixed relative to the imaging plane, and the second lens group G2 and the third lens group G3 move along an optical axis, to implement continuous zoom.

FIG. 5 is a zoom process of the zoom lens shown in FIG. 4. The zoom lens has four focal length states: W indicates the wide-angle state, M1 indicates a first intermediate focal length state, M2 indicates a second intermediate focal length state, and T indicates the telephoto state. The wide-angle state of the zoom lens corresponds to the following relative positions of the lens groups. The third lens group G3 is close to the imaging plane, and the second lens group G2 is close to an object side of the third lens group G3. When the zoom lens zooms from the wide-angle state W to the first intermediate focal length state M1, the second lens group G2 moves towards the first lens group G1, and the third lens group G3 moves towards the second lens group G2. When the zoom lens zooms from the first intermediate focal length state M1 to the second intermediate focal length state M2, the second lens group G2 continues to move towards the first lens group G1, and the third lens group G3 continues to move towards the second lens group G2. When the zoom lens zooms from the second intermediate focal length state M2 to the telephoto state T, the second lens group G2 continues to move towards the first lens group G1, and the third lens group G3 continues to move towards the second lens group G2.

It can be seen from FIG. 5 that when the zoom lens zooms from the wide-angle state W to the telephoto state T, both the second lens group G2 and the third lens group G3 keep moving towards the object side, but a distance between the third lens group G3 and the second lens group G2 first decreases and then increases, to implement continuous zoom. The second lens group G2 serves as a zoom lens group, and a ratio |L1/TTL| of a movement stroke L1 of the second lens group G2 along the optical axis to a total length TTL of the zoom lens from the surface closest to the object side to the imaging plane is 0.26178. The third lens group G3 serves as a compensation lens group, and a ratio |L2/TTL| of a movement stroke L2 of the third lens group G3 along the optical axis to the total length TTL of the zoom lens from the surface closest to the object side to the imaging plane is 0.256.

Refer to Table 1c and Table 1d correspondingly. Table 1c shows basic parameters of the zoom lens, and Table 1d shows spacing distances between the lens groups of the zoom lens in the wide-angle state W, the first intermediate focal length state M1, the second intermediate focal length state M2, and the telephoto state T.

TABLE 1c

W
M1
M2
T

Focal length F
11.5
mm
17
mm
24
mm
33.5
mm

F-number
2.54
3.44
4.28
5.10

Half-image
3
mm
3
mm
3
mm
3
mm

height IMH

Half FOV
15°
10.012°
7.085°
5.086°

BFL
1.37
mm
5.003
mm
7.665
mm
9.223
mm

TTL
30.56
mm
30.56
mm
30.56
mm
30.56
mm

Designed
650 nm, 610 nm, 555 nm, 510 nm, and 470 nm

wavelength

TABLE 1d

W
M1
M2
T

a2
9
mm
6.864
mm
4.049 mm
1.00
mm

a6
2.997
mm
1.5
mm
1.652 mm
3.144
mm

a8
0.080
mm
3.713
mm
6.375 mm
9.933
mm

Simulation is performed on the zoom lens shown in FIG. 4. The following describes imaging effect of the zoom lens with reference to the accompanying drawings.

FIG. 6a shows axial aberration curves of the zoom lens shown in FIG. 4 in the wide-angle state W. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.2621 mm. It can be seen from FIG. 6a that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.026 mm. In other words, axial aberrations of the zoom lens in the wide-angle state W are controlled within a small range.

FIG. 6b shows axial aberration curves of the zoom lens shown in FIG. 4 in the first intermediate focal length state M1. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.4669 mm. It can be seen from FIG. 6b that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.024 mm. In other words, axial aberrations of the zoom lens in the first intermediate focal length state M1 are controlled within a small range.

FIG. 6c shows axial aberration curves of the zoom lens shown in FIG. 4 in the second intermediate focal length state M2. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.8011 mm. It can be seen from FIG. 6c that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.020 mm. In other words, axial aberrations of the zoom lens in the second intermediate focal length state M2 are controlled within a small range.

FIG. 6d shows axial aberration curves of the zoom lens shown in FIG. 4 in the telephoto state T. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 3.2830 mm. It can be seen from FIG. 6d that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.020 mm. In other words, axial aberrations of the zoom lens in the telephoto state T are controlled within a small range.

FIG. 7a shows lateral chromatic aberration curves of the zoom lens in the wide-angle state W. Five solid curves in FIG. 7a are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 7a that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 7b shows lateral chromatic aberration curves of the zoom lens in the first intermediate focal length state M1. Five solid curves in FIG. 7b are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 7b that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 7c shows lateral chromatic aberration curves of the zoom lens in the second intermediate focal length state M2. Five solid curves in FIG. 7c are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 7c that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 7d shows lateral chromatic aberration curves of the zoom lens in the telephoto state T. Five solid curves in FIG. 7d are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 7d that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 8a shows optical distortion curves of the zoom lens in the wide-angle state W, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 8a that the differences between imaging deformations and ideal shapes are very small FIG. 8b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 8a. It can be seen from FIG. 8b that optical distortions can be controlled within a range less than 2.2%.

FIG. 9a shows optical distortion curves of the zoom lens in the first intermediate focal length state M1, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 9a that the differences between imaging deformations and ideal shapes are very small FIG. 9b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 9a. It can be seen from FIG. 9b that optical distortions can be controlled within a range less than 0.06%.

FIG. 10a shows optical distortion curves of the zoom lens in the second intermediate focal length state M2, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 10a that the differences between imaging deformations and ideal shapes are very small. FIG. 10b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 10a. It can be seen from FIG. 10b that optical distortions can be controlled within a range less than 0.6%.

FIG. 11a shows optical distortion curves of the zoom lens in the telephoto state T, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 11a that the differences between imaging deformations and ideal shapes are very small. FIG. 11b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 11a. It can be seen from FIG. 11b that optical distortions can be controlled within a range less than 0.8%.

FIG. 12 is an example of a second zoom lens. The zoom lens sequentially includes the following from an object side to an image side: a first lens group G1 with negative focal power, where a ratio of a focal length f1 of the first lens group G1 to a focal length ft (namely, a focal length when the zoom lens is in a telephoto state) at a telephoto end of the zoom lens is |f1/ft|=0.573; a second lens group G2 with positive focal power, where a ratio of a focal length f2 of the second lens group G2 to the focal length ft at the telephoto end of the zoom lens is |f2/ft|=0.282; and a third lens group G3 with negative focal power, where a ratio of a focal length f3 of the third lens group G3 to the focal length ft at the telephoto end of the zoom lens is |f3/ft|=0.147.

Still refer to FIG. 12. The zoom lens includes nine lenses with focal power and includes 12 aspheric surfaces in total. The first lens group G1 includes three lenses sequentially distributed from the object side to the image side, the three lenses are with positive, positive, and negative focal power respectively, and a first lens from the object side to the image side is a positive meniscus lens with a convex surface that bulges towards the object side. The second lens group G2 includes four lenses sequentially distributed from the object side to the image side, and the four lenses are with positive, positive, negative, and positive focal power respectively. The third lens group G3 includes two lenses sequentially distributed from the object side to the image side, and the two lenses are with positive and negative focal power respectively. The second lens group G2 includes at least one lens with negative focal power, to eliminate an aberration. In addition, the zoom lens further has a stop (not shown in FIG. 12). The stop is located on an object side of the second lens group G2 but is not limited thereto. Alternatively, the stop may be disposed on an image side or an object side of the first lens group G1 or may be disposed on an image side or an object side of the third lens group G3. A maximum aperture diameter of a lens in the first lens group G1, the second lens group G2, and the third lens group G3 is 10 mm.

Subsequently, refer to Table 2a and Table 2b. Table 2a shows a surface curvature, a thickness, a refractive index (nd), and an abbe coefficient (vd) of each lens of the zoom lens shown in FIG. 12 in a wide-angle state. For meanings of the parameters in Table 2a, refer to introduction in a corresponding part in Table 1a. Table 2b shows aspheric coefficients of aspheric surfaces of the lenses.

TABLE 2a

R
Thickness

nd

vd

R1
13.501
d1
1.8
n1
1.54
v1
56

R2
20.025
a1
1.748

R3
11.969
d2
1.544
n2
1.66
v2
20.4

R4
77.071
a2
1.183

R5
−10.290
d3
0.4
n3
1.91
v3
35.3

R6
18.347
a3
1

R7
6.250
d4
1.234
n4
1.54
v4
56.0

R8
−21.442
a4
1.568

R9
10.958
d5
1.213
n5
1.54
v5
56.0

R10
−16.983
a5
0.08

R11
−24.937
d6
0.534
n6
1.66
v6
20.4

R12
6.849
a6
4.495

R13
7.628
d7
0.701
n7
1.66
v7
20.4

R14
21.247
a7
3.415

R15
−32.639
d8
1.8
n8
1.66
v8
20.4

R16
−7.286
a8
0.444

R17
−4.677
d9
0.4
n9
1.88
v9
40.8

R18
−34.496
a9
7.745

TABLE 2b

Aspheric coefficient

Type
K
A2
A3
A4
A5
A6

R1
Even aspheric
0.00E+00
3.80E−04
4.50E−06
1.23E−07
1.55E−09
−5.05E−12

R2
Even aspheric
0.00E+00
4.50E−04
7.31E−06
−7.50E−08
1.84E−08
−6.36E−10

R3
Even aspheric
0.00E+00
4.93E−05
2.24E−06
1.74E−08
−3.50E−09
−1.20E−09

R4
Even aspheric
0.00E+00
−2.75E−04
−7.53E−07
2.40E−07
−5.43E−08
9.09E−10

R7
Even aspheric
0.00E+00
−7.82E−05
1.87E−05
−5.11E−07
5.98E−08
8.78E−10

R8
Even aspheric
0.00E+00
7.59E−04
1.41E−05
−9.68E−07
8.93E−08
−2.48E−09

R11
Even aspheric
0.00E+00
4.70E−04
2.32E−06
−5.32E−06
−1.06E−07
−2.10E−10

R12
Even aspheric
0.00E+00
6.35E−04
7.29E−05
1.06E−06
−1.01E−06
2.43E−08

R13
Even aspheric
0.00E+00
−9.69E−04
2.31E−05
2.15E−06
4.43E−07
−4.15E−08

R14
Even aspheric
0.00E+00
−6.38E−04
1.35E−05
3.99E−06
2.93E−07
−3.88E−08

R15
Even aspheric
0.00E+00
1.74E−03
2.22E−05
1.81E−05
−2.16E−06
1.48E−07

R16
Even aspheric
0.00E+00
8.17E−04
−9.76E−06
1.92E−05
−2.80E−06
1.98E−07

In the 12 aspheric surfaces of the zoom lens shown in Table 2b, surface types z of all the even aspheric surfaces may be defined according to, but not limited to, the following aspheric surface formula:

$z = \frac{{cr}^{2}}{1 + \sqrt{1 - {Kc}^{2} r^{2}}} + A_{2} r^{4} + A_{3} r^{6} + A_{4} r^{8} + A_{5} r^{10} + A_{6} r^{12},$

where

Because the zoom lens has the 12 aspheric surfaces, the aspheric surfaces may be flexibly designed, and a good aspheric surface type may be designed based on an actual requirement, to improve imaging quality.

A structure of the zoom lens shown in FIG. 12 is used for light to pass through. A ratio |TTL/ft| of a total length TTL of the zoom lens from a surface closest to the object side to the imaging plane to the effective focal length ft at the telephoto end of the zoom lens may reach 0.973. A small total optical length may be used to achieve a long focal length. A ratio |IMH/ft| of a half-image height IMH to the effective focal length ft at the telephoto end of the zoom lens may reach 0.08988.

As shown in FIG. 12, a position of the first lens group G1 is fixed relative to the imaging plane, and the second lens group G2 and the third lens group G3 move along an optical axis, to implement continuous zoom.

FIG. 13 is a zoom process of the zoom lens shown in FIG. 12. The zoom lens has four focal length states: W indicates the wide-angle state, M1 indicates a first intermediate focal length state, M2 indicates a second intermediate focal length state, and T indicates the telephoto state. The wide-angle state T of the zoom lens corresponds to the following relative positions of the lens groups. The third lens group G3 is close to the imaging plane, and the second lens group G2 is close to an object side of the third lens group G3. When the zoom lens zooms from the wide-angle state W to the first intermediate focal length state M1, the second lens group G2 moves towards the first lens group G1, and the third lens group G3 moves towards the second lens group G2. When the zoom lens zooms from the first intermediate focal length state M1 to the second intermediate focal length state M2, the second lens group G2 continues to move towards the first lens group G1, and the third lens group G3 continues to move towards the second lens group G2. When the zoom lens zooms from the second intermediate focal length state M2 to the telephoto state T, the second lens group G2 continues to move towards the first lens group G1, and the third lens group G3 continues to move towards the second lens group G2.

It can be seen from FIG. 13 that when the zoom lens zooms from the wide-angle state W to the telephoto state T, both the second lens group G2 and the third lens group G3 keep moving towards the object side, but a distance between the third lens group G3 and the second lens group G2 first decreases and then increases, to implement continuous zoom. The second lens group G2 serves as a zoom lens group, and a ratio |L1/TTL| of a movement stroke L1 of the second lens group G2 along the optical axis to a total length TTL of the zoom lens from the surface closest to the object side to the imaging plane is 0.2454. The third lens group G3 serves as a compensation lens group, and a ratio |L2/TTL| of a movement stroke L2 of the third lens group G3 along the optical axis to the total length TTL of the zoom lens from the surface closest to the object side to the imaging plane is 0.23512.

Refer to Table 2c and Table 2d correspondingly. Table 2c shows basic parameters of the zoom lens, and Table 2d shows spacing distances between the lens groups of the zoom lens in the wide-angle state W, the first intermediate focal length state M1, the second intermediate focal length state M2, and the telephoto state T.

TABLE 2c

W
M1
M2
T

Focal length F
11.5
mm
17
mm
24
mm
33.5
mm

F-number
2.43
3.27
4.03
4.76

Half-image
3
mm
3
mm
3
mm
3
mm

height IMH

Half FOV
14.7°
9.982°
7.081°
5.088°

BFL
1.37
mm
5.146
mm
7.748
mm
9.035
mm

TTL
32.6
mm
32.6
mm
32.6
mm
32.6
mm

Designed
650 nm, 610 nm, 555 nm, 510 nm, and 470 nm

wavelength

TABLE 2d

W
M1
M2
T

a3
9
mm
6.804
mm
3.994 mm
1.00
mm

a7
3.080
mm
1.5
mm
1.707 mm
3.415
mm

a9
0.080
mm
3.856
mm
6.458 mm
7.745
mm

Simulation is performed on the zoom lens shown in FIG. 12. The following describes imaging effect of the zoom lens with reference to the accompanying drawings.

FIG. 14a shows axial aberration curves of the zoom lens shown in FIG. 12 in the wide-angle state W. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.3651 mm. It can be seen from FIG. 14a that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.020 mm. In other words, axial aberrations of the zoom lens in the wide-angle state W are controlled within a small range.

FIG. 14b shows axial aberration curves of the zoom lens shown in FIG. 12 in the first intermediate focal length state M1. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.3651 mm. It can be seen from FIG. 14b that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.020 mm. In other words, axial aberrations of the zoom lens in the first intermediate focal length state M1 are controlled within a small range.

FIG. 14c shows axial aberration curves of the zoom lens shown in FIG. 12 in the second intermediate focal length state M2. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.9774 mm. It can be seen from FIG. 14c that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.020 mm. In other words, axial aberrations of the zoom lens in the second intermediate focal length state M2 are controlled within a small range.

FIG. 14d shows axial aberration curves of the zoom lens shown in FIG. 12 in the telephoto state T. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 3.5230 mm. It can be seen from FIG. 14d that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.022 mm. In other words, axial aberrations of the zoom lens in the telephoto state T are controlled within a small range.

FIG. 15a shows lateral chromatic aberration curves of the zoom lens in the wide-angle state W. Five solid curves in FIG. 15a are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 15a that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 15b shows lateral chromatic aberration curves of the zoom lens in the first intermediate focal length state M1. Five solid curves in FIG. 15b are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 15b that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 15c shows lateral chromatic aberration curves of the zoom lens in the second intermediate focal length state M2. Five solid curves in FIG. 15c are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 15c that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 15d shows lateral chromatic aberration curves of the zoom lens in the telephoto state T. Five solid curves in FIG. 15d are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 15d that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 16a shows optical distortion curves of the zoom lens in the wide-angle state W, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 16a that the differences between imaging deformations and ideal shapes are very small FIG. 16b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 16a. It can be seen from FIG. 16b that optical distortions can be controlled within a range less than 0.8%.

FIG. 17a shows optical distortion curves of the zoom lens in the first intermediate focal length state M1, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 17a that the differences between imaging deformations and ideal shapes are very small. FIG. 17b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 17a. It can be seen from FIG. 17b that optical distortions can be controlled within a range less than 0.3%.

FIG. 18a shows optical distortion curves of the zoom lens in the second intermediate focal length state M2, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 18a that the differences between imaging deformations and ideal shapes are very small. FIG. 18b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 18a. It can be seen from FIG. 18b that optical distortions can be controlled within a range less than 0.6%.

FIG. 19a shows optical distortion curves of the zoom lens in the telephoto state T, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 19a that the differences between imaging deformations and ideal shapes are very small FIG. 19b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 19a. It can be seen from FIG. 19b that optical distortions can be controlled within a range less than 0.8%.

FIG. 20 is an example of a third zoom lens. The zoom lens sequentially includes the following from an object side to an image side: a first lens group G1 with negative focal power, where a ratio of a focal length f1 of the first lens group G1 to a focal length ft (namely, a focal length when the zoom lens is in a telephoto state) at a telephoto end of the zoom lens is |f1/ft|=0.605; a second lens group G2 with positive focal power, where a ratio of a focal length f2 of the second lens group G2 to the focal length ft at the telephoto end of the zoom lens is |f2/ft|=0.283; and a third lens group G3 with negative focal power, where a ratio of a focal length f3 of the third lens group G3 to the focal length ft at the telephoto end of the zoom lens is |f3/ft|=0.298.

Still refer to FIG. 20. The zoom lens includes seven lenses with focal power and includes 12 aspheric surfaces in total. The first lens group G1 includes two lenses sequentially distributed from the object side to the image side, the two lenses are with positive and negative focal power respectively, and a first lens from the object side to the image side is a positive meniscus lens with a convex surface that bulges towards the object side. The second lens group G2 includes three lenses sequentially distributed from the object side to the image side, and the three lenses are with positive, negative, and positive focal power respectively. The third lens group G3 includes two lenses sequentially distributed from the object side to the image side, and the two lenses are with positive and negative focal power respectively. The second lens group G2 includes at least one lens with negative focal power, to eliminate an aberration. In addition, the zoom lens further has a stop (not shown in FIG. 20). The stop is located on an object side of the second lens group G2 but is not limited thereto. Alternatively, the stop may be disposed on an image side or an object side of the first lens group G1 or may be disposed on an image side or an object side of the third lens group G3. A maximum aperture diameter of a lens in the first lens group G1, the second lens group G2, and the third lens group G3 is 8.8 mm.

Subsequently, refer to Table 3a and Table 3b. Table 3a shows a surface curvature, a thickness, a refractive index (nd), and an abbe coefficient (vd) of each lens of the zoom lens shown in FIG. 20 in a wide-angle state. For meanings of the parameters in Table 3a, refer to introduction in a corresponding part in Table 1a. Table 3b shows aspheric coefficients of aspheric surfaces of the lenses.

TABLE 3a

R
Thickness
nd
vd

R1
12.53
d1
1.8
n1
1.67
v1
19.2

R2
63.007
a1
1.946

R3
−14.721
d2
0.4
n2
1.90
v2
31.3

R4
19.272
a2
9

R5
4.784
d3
2.164
n3
1.54
v3
56.0

R6
−10.174
a3
1.029

R7
−14.389
d4
1.344
n4
1.67
v4
19.2

R8
12.119
a4
4.220

R9
10.987
d5
0.745
n5
1.64
v5
24.0

R10
−938.402
a5
2.95

R11
−14.035
d6
1.8
n6
1.67
v6
19.2

R12
−4.939
a6
0.188

R13
−10.612
d7
0.923
n7
1.85
v7
40.1

R14
7.780
a7
0.199

TABLE 3b

Aspheric coefficient

Type
K
A2
A3
A4
A10
A12

R1
Even aspheric
0.00E+00
6.76E−05
2.92E−06
8.02E−08
−2.78E−09
9.24E−11

R2
Even aspheric
0.00E+00
−5.83E−05
4.75E−06
−9.49E−08
3.25E−09
−4.22E−11

R5
Even aspheric
0.00E+00
−4.78E−04
−1.17E−05
−1.51E−06
−2.32E−08
−3.54E−09

R6
Even aspheric
0.00E+00
9.84E−04
−4.88E−07
−1.13E−06
8.54E−09
1.02E−09

R7
Even aspheric
0.00E+00
5.98E−04
9.84E−05
2.922E−06
−4.96E−07
2.18E−08

R8
Even aspheric
0.00E+00
1.60E−03
1.90E−04
1.89E−05
−1.12E−06
1.43E−07

R9
Even aspheric
0.00E+00
−1.40E−03
−8.25E−05
3.43E−07
1.59E−06
−6.38E−08

R10
Even aspheric
0.00E+00
−1.22E−03
−1.05E−04
3.62E−06
1.12E−06
−4.29E−08

R11
Even aspheric
0.00E+00
4.05E−03
−2.52E−04
4.52E−05
−4.33E−06
2.11E−07

R12
Even aspheric
0.00E+00
5.43E−03
−1.09E−03
2.83E−04
−2.72E−05
8.57E−07

R13
Even aspheric
0.00E+00
−1.56E−02
1.20E−03
1.39E−04
−2.49E−05
8.21E−07

R14
Even aspheric
0.00E+00
−1.77E−02
2.95E−03
−3.44E−04
2.72E−05
−1.05E−06

In the 12 aspheric surfaces of the zoom lens shown in Table 3b, surface types z of all the even aspheric surfaces may be defined according to, but not limited to, the following aspheric surface formula:

$z = \frac{{cr}^{2}}{1 + \sqrt{1 - {Kc}^{2} r^{2}}} + A_{2} r^{4} + A_{3} r^{6} + A_{4} r^{8} + A_{5} r^{10} + A_{6} r^{12},$

where

A structure of the zoom lens shown in FIG. 20 is used. A ratio |TTL/ft| of a total length TTL of the zoom lens from a surface closest to the object side to the imaging plane to the effective focal length ft at the telephoto end of the zoom lens is 0.896. In view of this, a small total optical length may be used to achieve a long focal length. A ratio |IMH/ft| of a half-image height IMH to the effective focal length ft at the telephoto end of the zoom lens may reach 0.08961.

As shown in FIG. 20, a position of the first lens group G1 is fixed relative to the imaging plane, and the second lens group G2 and the third lens group G3 move along an optical axis, to implement continuous zoom.

FIG. 21 is a zoom process of the zoom lens shown in FIG. 20. The zoom lens has four focal length states: W indicates the wide-angle state, M1 indicates a first intermediate focal length state, M2 indicates a second intermediate focal length state, and T indicates the telephoto state. The wide-angle state T of the zoom lens corresponds to the following relative positions of the lens groups. The third lens group G3 is close to the imaging plane, and the second lens group G2 is close to an object side of the third lens group G3. When the zoom lens zooms from the wide-angle state W to the first intermediate focal length state M1, the second lens group G2 moves towards the first lens group G1, and the third lens group G3 moves towards the second lens group G2. When the zoom lens zooms from the first intermediate focal length state M1 to the second intermediate focal length state M2, the second lens group G2 continues to move towards the first lens group G1, and the third lens group G3 continues to move towards the second lens group G2. When the zoom lens zooms from the second intermediate focal length state M2 to the telephoto state T, the second lens group G2 continues to move towards the first lens group G1, and the third lens group G3 continues to move towards the second lens group G2.

It can be seen from FIG. 21 that when the zoom lens zooms from the wide-angle state W to the telephoto state T, both the second lens group G2 and the third lens group G3 keep moving towards the object side, but a distance between the third lens group G3 and the second lens group G2 first decreases and then increases, to implement continuous zoom. The second lens group G2 serves as a zoom lens group, and a ratio |L1/TTL| of a movement stroke L1 of the second lens group G2 along the optical axis to a total length TTL of the zoom lens from the surface closest to the object side to the imaging plane is 0.26667. The third lens group G3 serves as a compensation lens group, and a ratio |L2/TTL| of a movement stroke L2 of the third lens group G3 along the optical axis to the total length TTL of the zoom lens from the surface closest to the object side to the imaging plane is 0.27883.

Refer to Table 3c and Table 3d correspondingly. Table 3c shows basic parameters of the zoom lens, and Table 3d shows spacing distances between the lens groups of the zoom lens in the wide-angle state W, the first intermediate focal length state M1, the second intermediate focal length state M2, and the telephoto state T.

TABLE 3c

W
M1
M2
T

Focal length F
11.5
mm
17
mm
24
mm
33.5
mm

F-number
2.5
3.38
4.23
5.07

Half-image
3
mm
3
mm
3
mm
3
mm

height IMH

Half FOV
14.8°
10.03°
7.115°
5.106°

BFL
1.489
mm
5.129
mm
7.735
mm
9.854
mm

TTL
30
mm
30
mm
30
mm
30
mm

Designed
650 nm, 610 nm, 555 nm, 510 nm, and 470 nm

wavelength

TABLE 3d

W
M1
M2
T

a2
9
mm
6.804 mm
4.00
mm
1.00
mm

a5
2.950
mm
1.508 mm
1.500
mm
2.586
mm

a7
0.199
mm
3.839 mm
6.645
mm
8.564
mm

Simulation is performed on the zoom lens shown in FIG. 20. The following describes imaging effect of the zoom lens with reference to the accompanying drawings.

FIG. 22a shows axial aberration curves of the zoom lens shown in FIG. 20 in the wide-angle state W. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.3023 mm. It can be seen from FIG. 22a that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.030 mm. In other words, axial aberrations of the zoom lens in the wide-angle state W are controlled within a small range.

FIG. 22b shows axial aberration curves of the zoom lens shown in FIG. 20 in the first intermediate focal length state M1. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.5116 mm. It can be seen from FIG. 22b that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.030 mm. In other words, axial aberrations of the zoom lens in the first intermediate focal length state M1 are controlled within a small range.

FIG. 22c shows axial aberration curves of the zoom lens shown in FIG. 20 in the second intermediate focal length state M2. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.8403 mm. It can be seen from FIG. 22c that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.03 mm. In other words, axial aberrations of the zoom lens in the second intermediate focal length state M2 are controlled within a small range.

FIG. 22d shows axial aberration curves of the zoom lens shown in FIG. 20 in the telephoto state T. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 3.3048 mm. It can be seen from FIG. 22d that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.03 mm. In other words, axial aberrations of the zoom lens in the telephoto state T are controlled within a small range.

FIG. 23a shows lateral chromatic aberration curves of the zoom lens in the wide-angle state W. Five solid curves in FIG. 23a are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 23a that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 23b shows lateral chromatic aberration curves of the zoom lens in the first intermediate focal length state M1. Five solid curves in FIG. 23b are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 23b that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 23c shows lateral chromatic aberration curves of the zoom lens in the second intermediate focal length state M2. Five solid curves in FIG. 23c are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 23c that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 23d shows lateral chromatic aberration curves of the zoom lens in the telephoto state T. Five solid curves in FIG. 23d are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 23d that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 24a shows optical distortion curves of the zoom lens in the wide-angle state W, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 24a that the differences between imaging deformations and ideal shapes are very small FIG. 24b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 24a. It can be seen from FIG. 24b that optical distortions can be controlled within a range less than 1.6%.

FIG. 25a shows optical distortion curves of the zoom lens in the first intermediate focal length state M1, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 25a that the differences between imaging deformations and ideal shapes are very small. FIG. 25b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 25a. It can be seen from FIG. 25b that optical distortions can be controlled within a range less than 0.4%.

FIG. 26a shows optical distortion curves of the zoom lens in the second intermediate focal length state M2, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 26a that the differences between imaging deformations and ideal shapes are very small. FIG. 26b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 26a. It can be seen from FIG. 26b that optical distortions can be controlled within a range less than 1.2%.

FIG. 27a shows optical distortion curves of the zoom lens in the telephoto state T, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 27a that the differences between imaging deformations and ideal shapes are very small FIG. 27b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 27a. It can be seen from FIG. 27b that optical distortions can be controlled within a range less than 0.4%.

FIG. 28 is an example of a fourth zoom lens that may sequentially include the following from an object side to an image side: a first lens group G1 with negative focal power, where a ratio of a focal length f1 of the first lens group G1 to a focal length ft (namely, a focal length when the zoom lens is in a telephoto state) at a telephoto end of the zoom lens is |f1/ft|=0.796; a second lens group G2 with positive focal power, where a ratio of a focal length f2 of the second lens group G2 to the focal length ft at the telephoto end of the zoom lens is |f2/ft|=0.309; and a third lens group G3 with negative focal power, where a ratio of a focal length f3 of the third lens group G3 to the focal length ft at the telephoto end of the zoom lens is |f3/ft|=0.597.

The zoom lens includes seven lenses with focal power and includes 12 aspheric surfaces in total. The first lens group G1 includes two lenses sequentially distributed from the object side to the image side, and the two lenses are with positive and negative focal power respectively. The second lens group G2 includes three lenses sequentially distributed from the object side to the image side, and the three lenses are with positive, positive, and negative focal power respectively. The third lens group G3 includes two lenses sequentially distributed from the object side to the image side, and the two lenses are with positive and negative focal power respectively. The second lens group G2 includes at least one lens with negative focal power, to eliminate an aberration. In addition, the zoom lens further has a stop (not shown in FIG. 28). The stop is located on an object side of the second lens group G2 but is not limited thereto. Alternatively, the stop may be disposed on an image side or an object side of the first lens group G1 or may be disposed on an image side or an object side of the third lens group G3. A maximum aperture diameter of a lens in the first lens group G1, the second lens group G2, and the third lens group G3 is 9.788 mm.

Subsequently, refer to Table 4a and Table 4b. Table 4a shows a surface curvature, a thickness, a refractive index (nd), and an abbe coefficient (vd) of each lens of the zoom lens shown in FIG. 28 in a wide-angle state. For meanings of the parameters in Table 4a, refer to introduction in a corresponding part in Table 1a. Table 4b shows aspheric coefficients of aspheric surfaces of the lenses.

TABLE 4a

R
Thickness

nd

vd

R1
12.135
d1
2.571
n1
1.83
v1
37.3

R2
117.318
a1
1.395

R3
−11.290
d2
0.615
n2
1.80
v2
46.6

R4
13.747
a2
7.520

R5
11.884
d3
1.641
n3
1.54
v3
56.0

R6
−11.842
a3
1.836

R7
203.526
d4
1.878
n4
1.54
v4
56.0

R8
−5.655
a4
0.098

R9
−6.142
d5
2.344
n5
1.66
v5
20.4

R10
−13.570
a5
3.104

R11
−7.692
d6
2.952
n6
1.66
v6
20.4

R12
−6.243
a6
0.176

R13
−23.442
d7
2.077
n7
1.54
v7
56.0

R14
9.139
al
2.900

R15
Infinity
d8
0.258
n8
1.52
v8
64.2

R16
Infinity
a8
1.845

TABLE 4b

Aspheric coefficient

Type
K
A2
A3
A4
A5
A6

R1
Even aspheric
0.00
1.30E−04
2.11E−06
2.33E−07
−5.24E−09
1.91E−10

R2
Even aspheric
0.00
−3.18E−05
1.55E−06
2.54E−07
−1.77E−09
−1.19E−10

R5
Even aspheric
0.00
−1.28E−03
−4.21E−05
−7.95E−06
7.57E−07
−7.68E−08

R6
Even aspheric
0.00
−9.41E−04
−3.66E−05
−2.91E−06
7.03E−08
−2.72E−08

R7
Even aspheric
0.00
−3.89E−04
−9.79E−06
−5.48E−08
−8.82E−08
−5.01E−08

R8
Even aspheric
0.00
5.67E−04
−4.23E−06
−5.35E−06
−1.77E−07
1.11E−08

R9
Even aspheric
0.00
6.31E−04
2.77E−05
−5.67E−06
1.20E−08
4.01E−08

R10
Even aspheric
0.00
2.85E−04
4.37E−06
3.64E−07
−5.87E−09
4.61E−09

R11
Even aspheric
0.00
3.46E−03
−2.06E−04
2.75E−05
−2.13E−06
8.19E−08

R12
Even aspheric
0.00
9.60E−04
2.99E−05
1.51E−05
−2.09E−06
5.61E−08

R13
Even aspheric
0.00
−8.62E−03
3.47E−04
1.86E−05
−4.62E−06
1.54E−07

R14
Even aspheric
0.00
−7.88E−03
5.94E−04
−3.88E−05
1.50E−06
−2.50E−08

In the 12 aspheric surfaces of the zoom lens shown in Table 4b, surface types z of all the even aspheric surfaces may be defined according to, but not limited to, the following aspheric surface formula:

$z = \frac{{cr}^{2}}{1 + \sqrt{1 - {Kc}^{2} r^{2}}} + A_{2} r^{4} + A_{3} r^{6} + A_{4} r^{8} + A_{5} r^{10} + A_{6} r^{12},$

where

A structure of the zoom lens shown in FIG. 28 is used. A ratio |TTL/ft| of a total length TTL of the zoom lens from a surface closest to the object side to the imaging plane to the effective focal length ft at the telephoto end of the zoom lens is 1.15. In view of this, a small total optical length may be used to achieve a long focal length. A ratio |IMH/ft| of a half-image height IMH to the effective focal length ft at the telephoto end of the zoom lens may reach 0.139.

As shown in FIG. 28, a position of the first lens group G1 is fixed relative to the imaging plane, and the second lens group G2 and the third lens group G3 move along an optical axis, to implement continuous zoom.

FIG. 29 is a zoom process of the zoom lens shown in FIG. 28. The zoom lens has three focal length states: W indicates the wide-angle state, M indicates an intermediate focal length state, and T indicates the telephoto state. The wide-angle state T of the zoom lens corresponds to the following relative positions of the lens groups. The third lens group G3 is close to the imaging plane, and the second lens group G2 is close to an object side of the third lens group G3. When the zoom lens zooms from the wide-angle state W to the intermediate focal length state M, the second lens group G2 moves towards the first lens group G1, and the third lens group G3 moves towards the second lens group G2. When the zoom lens zooms from the intermediate focal length state M to the telephoto state T, the second lens group G2 continues to move towards the first lens group G1, and the third lens group G3 continues to move towards the second lens group G2.

It can be seen from FIG. 29 that when the zoom lens zooms from the wide-angle state W to the telephoto state T, both the second lens group G2 and the third lens group G3 keep moving towards the object side, but a distance between the third lens group G3 and the second lens group G2 first decreases and then increases, to implement continuous zoom. The second lens group G2 serves as a zoom lens group, and a ratio |L1/TTL| of a movement stroke L1 of the second lens group G2 along the optical axis to a total length TTL of the zoom lens from the surface closest to the object side to the imaging plane is 0.1988. The third lens group G3 serves as a compensation lens group, and a ratio |L2/TTL| of a movement stroke L2 of the third lens group G3 along the optical axis to the total length TTL of the zoom lens from the surface closest to the object side to the imaging plane is 0.222.

Refer to Table 4c and Table 4d correspondingly. Table 4c shows basic parameters of the zoom lens, and Table 4d shows spacing distances between the lens groups of the zoom lens in the wide-angle state W, the intermediate focal length state M, and the telephoto state T.

TABLE 4c

W
M
T

Focal length F (mm)
14.758
22.117
28.872

F-number
3.118
3.996
4.601

Half-image
4.000
4.000
4.000

height IMH (mm)

Half FOV (°)
15.524
10.342
7.901

BFL (mm)
5.003
9.956
12.383

TTL (mm)
33.210
33.215
33.210

Designed wavelength
650 nm, 610 nm, 555 nm, 510 nm, and 470 nm

TABLE 4d

W
M
T

a2
7.520 mm
3.620 mm
0.917 mm

a5
3.104 mm
2.056 mm
2.327 mm

a7
2.7 mm
7.852 mm
10.280 mm

Simulation is performed on the zoom lens shown in FIG. 28. The following describes imaging effect of the zoom lens with reference to the accompanying drawings.

FIG. 30a shows axial aberration curves of the zoom lens shown in FIG. 28 in the wide-angle state W. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.3931 mm. It can be seen from FIG. 30a that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.020 mm. In other words, axial aberrations of the zoom lens in the wide-angle state W are controlled within a small range.

FIG. 30b shows axial aberration curves of the zoom lens shown in FIG. 28 in the intermediate focal length state M. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.8062 mm. It can be seen from FIG. 30b that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.03 mm. In other words, axial aberrations of the zoom lens in the intermediate focal length state M are controlled within a small range.

FIG. 30c shows axial aberration curves of the zoom lens shown in FIG. 28 in the telephoto state T. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 3.1856 mm. It can be seen from FIG. 30c that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.03 mm. In other words, axial aberrations of the zoom lens in the telephoto state T are controlled within a small range.

FIG. 31a shows lateral chromatic aberration curves of the zoom lens in the wide-angle state W. Five solid curves in FIG. 31a are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 4.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 31a that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 31b shows lateral chromatic aberration curves of the zoom lens in the intermediate focal length state M. Five solid curves in FIG. 31b are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 4.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 31b that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 31c shows lateral chromatic aberration curves of the zoom lens in the telephoto state T. Five solid curves in FIG. 31c are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 4.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 31c that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 32a shows optical distortion curves of the zoom lens in the wide-angle state W, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 32a that the differences between imaging deformations and ideal shapes are very small FIG. 32b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 32a. It can be seen from FIG. 32b that optical distortions can be controlled within a range less than 3.0%.

FIG. 33a shows optical distortion curves of the zoom lens in the intermediate focal length state M, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 33a that the differences between imaging deformations and ideal shapes are very small. FIG. 33b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 33a. It can be seen from FIG. 33b that optical distortions can be controlled within a range less than 1.2%.

FIG. 34a shows optical distortion curves of the zoom lens in the telephoto state T, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 34a that the differences between imaging deformations and ideal shapes are very small FIG. 34b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 34a. It can be seen from FIG. 34b that optical distortions can be controlled within a range less than 0.4%.

According to the four embodiments provided in FIG. 4 to FIG. 34b, a case in which the zoom lens includes three lens groups: the first lens group G1, the second lens group G2, and the third lens group G3 is described above as an example. A form of the zoom lens includes the form of three lens groups. However, this is not limited to the foregoing forms.

A ratio of a focal length of each lens groups to the focal length ft at the telephoto end of the zoom lens is not limited to the values in the embodiments provided in FIG. 4 to FIG. 34b. Continuous zoom can be implemented as long as the focal length of each lens group and the focal length at the telephoto end of the zoom lens meet the following ratio relationship: For example, the focal length f1 of the first lens group G1 and the focal length ft at the telephoto end of the zoom lens meet 0.2≤|f1/ft|≤0.9, the focal length f2 of the second lens group G2 and ft meet 0.10≤|f2/ft|≤0.6, and the focal length f3 of the third lens group G3 and ft meet 0.10≤|f3/ft|≤0.7.

A quantity of lenses included in each lens group in the four embodiments provided in FIG. 4 to FIG. 34b is merely an example. The quantity of lenses in each lens group is not limited for the zoom lens provided in the embodiments, and only a total quantity N of lenses in the first lens group G1, the second lens group G2, and the third lens group G3 is limited. For example, each lens group may include one, two, or more lenses. The total quantity N of lenses in the first lens group G1, the second lens group G2, and the third lens group G3 needs to meet 7≤N≤11, to ensure that the zoom lens has a good continuous zoom capability and imaging effect. For example, N may be different positive integers such as 7, 8, 9, 10, or 11. In addition, all lenses included in the first lens group G1, the second lens group G2, and the third lens group G3 meet N≤quantity of aspheric surfaces≤2N, where the quantity of aspheric surfaces is a quantity of aspheric surfaces of all lenses included in the first lens group G1, the second lens group G2, and the third lens group G3, and N is the total quantity of lenses in the first lens group G1, the second lens group G2, and the third lens group G3. For example, the quantity of aspheric surfaces may be N, 1.2N, 1.5N, 1.7N, or 2N. The aspheric surface is a transparent surface of a lens.

In the four embodiments provided in FIG. 4 to FIG. 34b, in a sliding process of the second lens group G2 and the third lens group G3, the ratio |L1/TTL| of the movement stroke L1 of the second lens group G2 along the optical axis to the total length TTL of the zoom lens from the surface closest to the object side to the imaging plane, and the ratio |L2/TTL| of the movement stroke L2 of the third lens group G3 along the optical axis to the total length TTL of the zoom lens from the surface closest to the object side to the imaging plane are merely examples. Only the ratio of the movement stroke L1 of the second lens group G2 along the optical axis to the total length TTL of the zoom lens from the surface closest to the object side to the imaging plane needs to meet 0.12≤|L1/TTL|≤0.35. For example, the ratio may be 0.12, 0.16, 0.19, 0.20, 0.25, 0.30, 0.33, or 0.35. The ratio of the movement stroke L2 of the third lens group G3 along the optical axis to the total length TTL of the zoom lens from the surface closest to the object side to the imaging plane meets 0.08≤|L2/TTL|≤0.35. For example, the ratio may be 0.08, 0.12, 0.16, 0.19, 0.20, 0.25, 0.30, 0.33, or 0.35. In other words, the second lens group G2 and the third lens group G3 can cooperate with each other to achieve continuous zoom.

After the zoom lens of the foregoing structure is used, the ratio |TTL/ft| of the total length TTL of the zoom lens from the surface closest to the object side to the imaging plane to the effective focal length ft at the telephoto end of the zoom lens meets 0.8≤|TTL/ft|≤1.2. This helps achieve a long focal length by using a short total optical length. The ratio |IMH/ft| of the half-image height IMH to the effective focal length ft at the telephoto end of the zoom lens meets 0.02≤|IMH/ft|≤0.20. For example, the ratio may be 0.02, 0.05, 0.07, 0.12, 0.15, 0.18, or 0.20. The effective focal length ft at the telephoto end of the zoom lens and an effective focal length fw of the wide-angle end of the zoom lens meet 1≤|ft/fw|≤3.7. For example, the ratio may be 1, 1.2, 1.6, 1.7, 1.9, 2.2, 2.5, 2.8, 3, 3.3, or 3.7, to obtain better imaging quality during continuous zoom.

In addition to the zoom lens including the three lens groups, a fourth lens group G4 may be added on the basis of the zoom lens including the three lens groups shown in FIG. 2, and a related parameter is adaptively adjusted, to maintain a continuous zoom capability. The fourth lens group G4 is located on an image side of the third lens group G3, and the fourth lens group G4 is a lens group with positive focal power. The fourth lens group G4 is a lens group fixed relative to the imaging plane. The second lens group G2 serving as the zoom lens group and the third lens group G3 serving as the compensation lens group move between the first lens group G1 and the fourth lens group G4 along the optical axis of the zoom lens. The fourth lens group G4 is disposed to increase resolution of the zoom lens to obtain a clearer image and improve photographing quality.

Similarly, a lens structure similar to that shown in FIG. 3 may also be used in each lens in the fourth lens group G4, to increase luminous flux and reduce a size in a height direction. A maximum aperture diameter of a lens included in the first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens group G4 meets 4 mm≤maximum aperture diameter d≤12 mm, so that the zoom lens can balance an amount of light passing through the zoom lens and space occupied by the zoom lens. In addition, the lens in the fourth lens group G4 may also have a cut similar to the cut 11 of the lens 10 (FIG. 3). A height in a vertical direction of each lens in the first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens group G4 meets 4 mm≤height in the vertical direction≤6 mm, to reduce a height of the zoom lens.

The following uses embodiments to describe photographing effect of the zoom lens having four lens groups.

FIG. 35 is an example of a fifth zoom lens that may sequentially include the following from an object side to an image side: a first lens group G1 with negative focal power, where a ratio of a focal length f1 of the first lens group G1 to a focal length ft at a telephoto end of the zoom lens is |f1/ft|=0.556; a second lens group G2 with positive focal power, where a ratio of a focal length f2 of the second lens group G2 to the focal length ft at the telephoto end of the zoom lens is |f2/ft|=0.241; a third lens group G3 with negative focal power, where a ratio of a focal length f3 of the third lens group G3 to the focal length ft at the telephoto end of the zoom lens is |f3/ft|=0.211; and a fourth lens group G4 with positive focal power, where a ratio of a focal length f4 of the fourth lens group G4 to the focal length ft at the telephoto end of the zoom lens is |f4/ft|=0.286.

Still refer to FIG. 35. The zoom lens includes nine lenses with focal power and includes 16 aspheric surfaces in total. The first lens group G1 includes two lenses sequentially distributed from the object side to the image side, the two lenses are with positive and negative focal power respectively, and a first lens from the object side to the image side is a positive meniscus lens with a convex surface that bulges towards the object side. The second lens group G2 includes four lenses sequentially distributed from the object side to the image side, and the four lenses are with positive, positive, negative, and positive focal power respectively. The third lens group G3 includes two lenses sequentially distributed from the object side to the image side, and the two lenses are with positive and negative focal power respectively. The fourth lens group G4 includes one lens with positive focal power. The second lens group G2 includes at least one lens with negative focal power, to eliminate an aberration. In addition, the zoom lens further has a stop (not shown in FIG. 35). The stop is located on an object side of the second lens group G2 but is not limited thereto. Alternatively, the stop may be disposed on an image side or an object side of the first lens group G1 or may be disposed on an image side or an object side of the third lens group G3. A maximum aperture diameter of a lens in the first lens group G1, the second lens group G2, and the third lens group G3 is 9.6 mm.

Subsequently, refer to Table 5a and Table 5b. Table 5a shows a surface curvature, a thickness, a refractive index (nd), and an abbe coefficient (vd) of each lens of the zoom lens shown in FIG. 35 in a wide-angle state. For meanings of the parameters in Table 5a, refer to introduction in a corresponding part in Table 1a. Table 5b shows aspheric coefficients of aspheric surfaces of the lenses.

TABLE 5a

R
Thickness

nd

vd

R1
10.428
d1
1.8
n1
1.67
v1
19.2

R2
15.057
a1
3.754

R3
−10.087
d2
0.4
n2
1.54
v2
56.0

R4
14.959
a2
9

R5
5.840
d3
1.832
n3
1.54
v3
56.0

R6
−24.614
a3
1.110

R7
9.85
d4
1.749
n4
1.50
v4
81.6

R8
−13.99
a4
0.080

R9
−32.867
d5
0.664
n5
1.67
v5
19.2

R10
5.913
a5
1.409

R11
8.285
d6
1.699
n6
1.67
v6
19.2

R12
17.979
a6
1.600

R13
−6.522
d7
1.800
n7
1.66
v7
20.4

R14
−4.515
a7
0.322

R15
−8.790
d8
1.626
n8
1.54
v8
56.0

R16
4.415
a8
0.677

R17
11.476
d9
1.298
n9
1.66
v9
20.4

R18
−13.374
a9
0.5

TABLE 5b

Aspheric coefficient

Type
K
A2
A3
A4
A5
A6

R1
Even aspheric
0.00E+00
−4.36E−05
7.34E−07
5.28E−08
1.01E−09
−4.53E−11

R2
Even aspheric
0.00E+00
−1.57E−04
5.27E−07
1.61E−07
−3.39E−10
−1.12E−10

R3
Even aspheric
0.00E+00
1.10E−04
8.91E−06
4.90E−07
−3.58E−08
3.07E−10

R4
Even aspheric
0.00E+00
4.64E−05
9.09E−06
−1.97E−07
1.117E−08
−8.89E−10

R5
Even aspheric
0.00E+00
−3.10E−04
5.88E−06
−6.57E−07
4.01E−08
−5.08E−10

R6
Even aspheric
0.00E+00
4.57E−04
1.14E−05
−9.08E−07
6.51E−08
−1.51E−09

R9
Even aspheric
0.00E+00
5.01E−06
−2.13E−05
−1.21E−06
−1.28E−07
9E−10

R10
Even aspheric
0.00E+00
9.03E−04
6.57E−05
3.27E−06
−6.83E−08
−8.28E−08

R11
Even aspheric
0.00E+00
−1.04E−03
1.70E−05
−3.21E−06
4.29E−07
−7.84E−08

R12
Even aspheric
0.00E+00
−1.13E−03
−1.30E−05
−9.06E−06
1.14E−06
−8.80E−08

R13
Even aspheric
0.00E+00
8.37E−03
−6.30E−04
8.75E−05
−7.56E−06
3.21E−07

R14
Even aspheric
0.00E+00
6.12E−03
−6.46E−04
1.65E−04
−1.79E−05
5.24E−07

R15
Even aspheric
0.00E+00
−1.77E−02
8.68E−04
2.34E−04
−4.56E−05
2.20E−06

R16
Even aspheric
0.00E+00
−1.97E−02
2.88E−03
−3.20E−04
2.23E−05
−7.14E−07

R17
Even aspheric
0.00E+00
−1.44E−04
−3.95E−06
9.01E−07
1.08E−07
−1.78E−08

R18
Even aspheric
0.00E+00
−1.02E−03
8.32E−05
2.92E−06
−5.31E−07
6.42E−09

In the 16 aspheric surfaces of the zoom lens shown in Table 5b, surface types z of all the even aspheric surfaces may be defined according to, but not limited to, the following aspheric surface formula:

$z = \frac{{cr}^{2}}{1 + \sqrt{1 - {Kc}^{2} r^{2}}} + A_{2} r^{4} + A_{3} r^{6} + A_{4} r^{8} + A_{5} r^{10} + A_{6} r^{12},$

where

Because the zoom lens has the 16 aspheric surfaces, the aspheric surfaces may be flexibly designed, and a good aspheric surface type may be designed based on an actual requirement, to improve imaging quality.

A structure of the zoom lens shown in FIG. 35 is used. A ratio |TTL/ft| of a total length TTL of the zoom lens from a surface closest to the object side to the imaging plane to the effective focal length ft at the telephoto end of the zoom lens is 0.97. In view of this, a small total optical length may be used to achieve a long focal length. A ratio |IMH/ft| of a half-image height IMH to the effective focal length ft at the telephoto end of the zoom lens may reach 0.08955.

As shown in FIG. 35, positions of the first lens group G1 and the fourth lens group G4 are fixed relative to the imaging plane, and the second lens group G2 and the third lens group G3 move along an optical axis between the first lens group G1 and the fourth lens group G4. The second lens group G2 serves as a zoom lens group, and the third lens group G3 serves as a compensation lens group, to implement continuous zoom.

FIG. 36 is a zoom process of the zoom lens shown in FIG. 35. The zoom lens has four focal length states: W indicates the wide-angle state, M1 indicates a first intermediate focal length state, M2 indicates a second intermediate focal length state, and T indicates a telephoto state. The wide-angle state T of the zoom lens corresponds to the following relative positions of the lens groups. The third lens group G3 is close to the fourth lens group G4, and the second lens group G2 is close to an object side of the third lens group G3. When the zoom lens zooms from the wide-angle state W to the first intermediate focal length state M1, the second lens group G2 moves towards the first lens group G1, and the third lens group G3 moves towards the second lens group G2. When the zoom lens zooms from the first intermediate focal length state M1 to the second intermediate focal length state M2, the second lens group G2 continues to move towards the first lens group G1, and the third lens group G3 continues to move towards the second lens group G2. When the zoom lens zooms from the second intermediate focal length state M2 to the telephoto state T, the second lens group G2 continues to move towards the first lens group G1, and the third lens group G3 continues to move towards the second lens group G2.

It can be seen from FIG. 36 that when the zoom lens zooms from the wide-angle state W to the telephoto state T, both the second lens group G2 and the third lens group G3 keep moving towards the object side, but a distance between the third lens group G3 and the second lens group G2 first decreases and then increases, to implement continuous zoom. The second lens group G2 serves as a zoom lens group, and a ratio |L1/TTL| of a movement stroke L1 of the second lens group G2 along the optical axis to a total length TTL of the zoom lens from the surface closest to the object side to the imaging plane is 0.24615. The third lens group G3 serves as a compensation lens group, and a ratio |L2/TTL| of a movement stroke L2 of the third lens group G3 along the optical axis to the total length TTL of the zoom lens from the surface closest to the object side to the imaging plane is 0.17871.

Refer to Table 5c and Table 5d correspondingly. Table 5c shows basic parameters of the zoom lens, and Table 5d shows spacing distances between the lens groups of the zoom lens in the wide-angle state W, the first intermediate focal length state M1, the second intermediate focal length state M2, and the telephoto state T. Table Se shows chief ray angle values (CRA values) of the zoom lens in different fields of view in the wide-angle state W, the first intermediate focal length state M1, the second intermediate focal length state M2, and the telephoto state T. Numbers in a left column indicate different fields of view.

TABLE 5c

W
M1
M2
T

Focal length F
11.5 mm

17 mm

24 mm
33.5 mm

F-number
2.56
3.37
4.19
5.05

Half-image
3 mm
3 mm
3 mm
3 mm

height IMH

Half FOV
15°
10.0°
7.10°
5.09°

BFL
1.71 mm
1.71 mm
1.71 mm
1.71 mm

TTL
32.5 mm
32.5 mm
32.5 mm
32.5 mm

Designed
650 nm, 610 nm, 555 nm, 510 nm, and 470 nm

wavelength

TABLE 5d

W
M1
M2
T

a2
9.000 mm
6.341 mm
3.666 mm
1.000 mm

a6
1.600 mm
1.500 mm
2.183 mm
3.792 mm

a8
0.677 mm
3.436 mm
5.428 mm
6.485 mm

TABLE 5e

W
M1
M2
T

0
0
0
0
0

0.2
2.068
0.406
−0.406
−0.79

0.4
3.924
0.583
−1.052
−1.83

0.6
5.457
0.449
−1.987
−3.15

0.8
6.60
0.128
−3.04
−4.56

1
8.18
−0.488
−4.40
−6.27

Simulation is performed on the zoom lens shown in FIG. 35. The following describes imaging effect of the zoom lens with reference to the accompanying drawings.

FIG. 37a shows axial aberration curves of the zoom lens shown in FIG. 35 in the wide-angle state W. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.2529 mm. It can be seen from FIG. 37a that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.020 mm. In other words, axial aberrations of the zoom lens in the wide-angle state W are controlled within a small range.

FIG. 37b shows axial aberration curves of the zoom lens shown in FIG. 35 in the first intermediate focal length state M1. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.5228 mm. It can be seen from FIG. 37b that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.040 mm. In other words, axial aberrations of the zoom lens in the first intermediate focal length state M1 are controlled within a small range.

FIG. 37c shows axial aberration curves of the zoom lens shown in FIG. 35 in the second intermediate focal length state M2. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.8687 mm. It can be seen from FIG. 37c that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.03 mm. In other words, axial aberrations of the zoom lens in the second intermediate focal length state M2 are controlled within a small range.

FIG. 37d shows axial aberration curves of the zoom lens shown in FIG. 35 in the telephoto state T. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 3.3225 mm. It can be seen from FIG. 37d that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.05 mm. In other words, axial aberrations of the zoom lens in the telephoto state T are controlled within a small range.

FIG. 38a shows lateral chromatic aberration curves of the zoom lens in the wide-angle state W. Five solid curves in FIG. 38a are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 38a that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 38b shows lateral chromatic aberration curves of the zoom lens in the first intermediate focal length state M1. Five solid curves in FIG. 38b are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 38b that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 38c shows lateral chromatic aberration curves of the zoom lens in the second intermediate focal length state M2. Five solid curves in FIG. 38c are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 38c that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 38d shows lateral chromatic aberration curves of the zoom lens in the telephoto state T. Five solid curves in FIG. 38d are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 38d that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 39a shows optical distortion curves of the zoom lens in the wide-angle state W, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 39a that the differences between imaging deformations and ideal shapes are very small FIG. 39b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 39a. It can be seen from FIG. 39b that optical distortions can be controlled within a range less than or equal to 3%.

FIG. 40a shows optical distortion curves of the zoom lens in the first intermediate focal length state M1, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 40a that the differences between imaging deformations and ideal shapes are very small. FIG. 40b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 40a. It can be seen from FIG. 40b that optical distortions can be controlled within a range less than 0.8%.

FIG. 41a shows optical distortion curves of the zoom lens in the second intermediate focal length state M2, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 41a that the differences between imaging deformations and ideal shapes are very small. FIG. 41b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 41a. It can be seen from FIG. 41b that optical distortions can be controlled within a range less than 0.5%.

FIG. 42a shows optical distortion curves of the zoom lens in the telephoto state T, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 42a that the differences between imaging deformations and ideal shapes are very small FIG. 42b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 42a. It can be seen from FIG. 42b that optical distortions can be controlled within a range less than 0.8%.

FIG. 43 is an example of a sixth zoom lens that may sequentially include the following from an object side to an image side: a first lens group G1 with negative focal power, where a ratio of a focal length f1 of the first lens group G1 to a focal length ft at a telephoto end of the zoom lens is |f1/ft|=0.579; a second lens group G2 with positive focal power, where a ratio of a focal length f2 of the second lens group G2 to the focal length ft at the telephoto end of the zoom lens is |f2/ft|=0.260; a third lens group G3 with negative focal power, where a ratio of a focal length f3 of the third lens group G3 to the focal length ft at the telephoto end of the zoom lens is |f3/ft|=0.205; and a fourth lens group G4 with positive focal power, where a ratio of a focal length f4 of the fourth lens group G4 to the focal length ft at the telephoto end of the zoom lens is |f4/ft|=0.307.

The zoom lens includes eight lenses with focal power and includes 14 aspheric surfaces in total. The first lens group G1 includes two lenses sequentially distributed from the object side to the image side, the two lenses are with positive and negative focal power respectively, and a first lens from the object side to the image side is a positive meniscus lens with a convex surface that bulges towards the object side. The second lens group G2 includes three lenses sequentially distributed from the object side to the image side, and the three lenses are with positive, negative, and positive focal power respectively. The third lens group G3 includes two lenses sequentially distributed from the object side to the image side, and the two lenses are with positive and negative focal power respectively. The fourth lens group G4 includes one lens with positive focal power. The second lens group G2 includes at least one lens with negative focal power, to eliminate an aberration. In addition, the zoom lens further has a stop (not shown in FIG. 43). The stop is located on an object side of the second lens group G2 but is not limited thereto. Alternatively, the stop may be disposed on an image side or an object side of the first lens group G1 or may be disposed on an image side or an object side of the third lens group G3. A maximum aperture diameter of a lens in the first lens group G1, the second lens group G2, and the third lens group G3 is 9.6 mm.

Subsequently, refer to Table 6a and Table 6b. Table 6a shows a surface curvature, a thickness, a refractive index (nd), and an abbe coefficient (vd) of each lens of the zoom lens shown in FIG. 43 in a wide-angle state. For meanings of the parameters in Table 6a, refer to introduction in a corresponding part in Table 1a. Table 6b shows aspheric coefficients of aspheric surfaces of the lenses.

TABLE 6a

R
Thickness

nd

vd

R1
10.589
d1
1.8
n1
1.64
v1
24

R2
20.363
a1
3.449

R3
−9.802
d2
0.4
n2
1.54
v2
56.0

R4
12.424
a2
9

R5
5.065
d3
2.234
n3
1.50
v3
81.6

R6
−13.319
a3
1.800

R7
−34.719
d4
1.800
n4
1.57
v4
19.2

R8
13.701
a4
0.585

R9
6.697
d5
1.800
n5
1.54
v5
56

R10
27.4
a5
1.901

R11
−6.952
d6
1.800
n6
1.57
v6
19.2

R12
−4.775
a6
0.437

R13
−7.759
d7
1.417
n7
1.54
v7
56.0

R14
4.642
a7
0.695

R15
13.343
d8
1.15
n8
1.57
v8
19.2

R16
−13.825
a8
0.5

TABLE 6b

Aspheric coefficient

Type
K
A2
A3
A4
A5
A6

R1
Even aspheric
0.00E+00
1.32E−04
1.23E−06
8.81E−08
−1.70E−09
1.37E−10

R2
Even aspheric
0.00E+00
1.04E−04
−3.97E−07
−1.52E−09
8.22E−09
−2.46E−11

R3
Even aspheric
0.00E+00
1.12E−04
1.12E−06
6.96E−07
−9.87E−09
−5.21E−10

R4
Even aspheric
0.00E+00
−1.18E−04
8.91E−06
−7.40E−08
2.75E−08
−1.58E−09

R5
Even aspheric
0.00E+00
−4.96E−04
−1.83E−06
−9.26E−07
4.85E−08
−1.84E−09

R6
Even aspheric
0.00E+00
5.99E−04
6.86E−06
−2.80E−07
7.57E−09
−2.83E−10

R7
Even aspheric
0.00E+00
2.19E−04
1.53E−05
1.87E−06
−2.77E−07
−2.96E−09

R8
Even aspheric
0.00E+00
1.05E−03
6.42E−05
8.67E−06
9.80E−08
−3.82E−08

R9
Even aspheric
0.00E+00
−5.81E−04
−5.40E−05
−6.47E−06
5.71E−07
−6.46E−08

R10
Even aspheric
0.00E+00
8.02E−05
−8.68E−05
−1.93E−05
1.62E−06
−6.72E−08

R11
Even aspheric
0.00E+00
7.37E−03
−5.79E−04
8.36E−05
−6.94E−06
2.86E−07

R12
Even aspheric
0.00E+00
6.28E−03
−8.88E−04
1.92E−04
−1.89E−05
5.76E−07

R13
Even aspheric
0.00E+00
−1.70E−02
8.83E−04
2.14E−04
−4.35E−05
2.13E−06

R14
Even aspheric
0.00E+00
−1.96E−02
3.10E−03
−3.58E−04
2.55E−05
−8.37E−07

In the 14 aspheric surfaces of the zoom lens shown in Table 6b, surface types z of all the even aspheric surfaces may be defined according to, but not limited to, the following aspheric surface formula:

$z = \frac{{cr}^{2}}{1 + \sqrt{1 - {Kc}^{2} r^{2}}} + A_{2} r^{4} + A_{3} r^{6} + A_{4} r^{8} + A_{5} r^{10} + A_{6} r^{12},$

where

Because the zoom lens has the 14 aspheric surfaces, the aspheric surfaces may be flexibly designed, and a good aspheric surface type may be designed based on an actual requirement, to improve imaging quality.

A structure of the zoom lens shown in FIG. 43 is used. A ratio |TTL/ft| of a total length TTL of the zoom lens from a surface closest to the object side to the imaging plane to the effective focal length ft at the telephoto end of the zoom lens is 0.955. In view of this, a small total optical length may be used to achieve a long focal length. A ratio |IMH/ft| of a half-image height IMH to the effective focal length ft at the telephoto end of the zoom lens may reach 0.08955.

As shown in FIG. 43, positions of the first lens group G1 and the fourth lens group G4 are fixed relative to the imaging plane, and the second lens group G2 and the third lens group G3 move along an optical axis between the first lens group G1 and the fourth lens group G4. The second lens group G2 serves as a zoom lens group, and the third lens group G3 serves as a compensation lens group, to implement continuous zoom.

FIG. 44 is a zoom process of the zoom lens shown in FIG. 43. The zoom lens has four focal length states: W indicates the wide-angle state, M1 indicates a first intermediate focal length state, M2 indicates a second intermediate focal length state, and T indicates a telephoto state. The wide-angle state T of the zoom lens corresponds to the following relative positions of the lens groups. The third lens group G3 is close to the fourth lens group G4, and the second lens group G2 is close to an object side of the third lens group G3. When the zoom lens zooms from the wide-angle state W to the first intermediate focal length state M1, the second lens group G2 moves towards the first lens group G1, and the third lens group G3 moves towards the second lens group G2. When the zoom lens zooms from the first intermediate focal length state M1 to the second intermediate focal length state M2, the second lens group G2 continues to move towards the first lens group G1, and the third lens group G3 continues to move towards the second lens group G2. When the zoom lens zooms from the second intermediate focal length state M2 to the telephoto state T, the second lens group G2 continues to move towards the first lens group G1, and the third lens group G3 continues to move towards the second lens group G2.

It can be seen from FIG. 44 that when the zoom lens zooms from the wide-angle state W to the telephoto state T, both the second lens group G2 and the third lens group G3 keep moving towards the object side, but a distance between the third lens group G3 and the second lens group G2 first decreases and then increases, to implement continuous zoom. The second lens group G2 serves as a zoom lens group, and a ratio |L1/TTL| of a movement stroke L1 of the second lens group G2 along the optical axis to a total length TTL of the zoom lens from the surface closest to the object side to the imaging plane is 0.25016. The third lens group G3 serves as a compensation lens group, and a ratio |L2/TTL| of a movement stroke L2 of the third lens group G3 along the optical axis to the total length TTL of the zoom lens from the surface closest to the object side to the imaging plane is 0.20385.

Refer to Table 6c, Table 6d, and Table 6e correspondingly. Table 6c shows basic parameters of the zoom lens, and Table 6d shows spacing distances between the lens groups of the zoom lens in the wide-angle state W, the first intermediate focal length state M1, the second intermediate focal length state M2, and the telephoto state T. Table 6e shows chief ray angle values (CRA values) of the zoom lens in different fields of view in the wide-angle state W, the first intermediate focal length state M1, the second intermediate focal length state M2, and the telephoto state T.

TABLE 6c

W
M1
M2
T

Focal length F
11.5 mm

17 mm

24 mm
33.5 mm

F-number
2.48
3.29
4.09
4.93

Half-image
3 mm
3 mm
3 mm
3 mm

height IMH

Half FOV
14.9°
9.95°
7.06°
5.07°

BFL
1.71 mm
1.71 mm
1.71 mm
1.71 mm

TTL
32.5 mm
32.5 mm
32.5 mm
32.5 mm

Designed
650 nm, 610 nm, 555 nm, 510 nm, and 470 nm

wavelength

TABLE 6d

W
M1
M2
T

a2
9.000 mm
6.341 mm
3.666 mm
1.000 mm

a6
1.600 mm
1.500 mm
2.183 mm
3.792 mm

a8
0.677 mm
3.436 mm
5.428 mm
6.485 mm

TABLE 6e

W
M1
M2
T

0
0
0
0
0

0.2
2.29
0.65
−0.18
−0.62

0.4
4.48
1.21
−0.43
−1.30

0.6
6.49
1.59
−0.84
−2.14

0.8
7.99
1.71
−1.51
−3.23

1
8.43
1.45
−2.55
−4.69

Simulation is performed on the zoom lens shown in FIG. 43. The following describes imaging effect of the zoom lens with reference to the accompanying drawings.

FIG. 45a shows axial aberration curves of the zoom lens shown in FIG. 43 in the wide-angle state W. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.3197 mm. It can be seen from FIG. 45a that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.020 mm. In other words, axial aberrations of the zoom lens in the wide-angle state W are controlled within a small range.

FIG. 45b shows axial aberration curves of the zoom lens shown in FIG. 43 in the first intermediate focal length state M1. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.5893 mm. It can be seen from FIG. 45b that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.03 mm. In other words, axial aberrations of the zoom lens in the first intermediate focal length state M1 are controlled within a small range.

FIG. 45c shows axial aberration curves of the zoom lens shown in FIG. 43 in the second intermediate focal length state M2. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.9403 mm. It can be seen from FIG. 45c that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.04 mm. In other words, axial aberrations of the zoom lens in the second intermediate focal length state M2 are controlled within a small range.

FIG. 45d shows axial aberration curves of the zoom lens shown in FIG. 43 in the telephoto state T. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 3.4027 mm. It can be seen from FIG. 45d that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.05 mm. In other words, axial aberrations of the zoom lens in the telephoto state T are controlled within a small range.

FIG. 46a shows lateral chromatic aberration curves of the zoom lens in the wide-angle state W. Five solid curves in FIG. 46a are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 46a that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 46b shows lateral chromatic aberration curves of the zoom lens in the first intermediate focal length state M1. Five solid curves in FIG. 46b are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 46b that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 46c shows lateral chromatic aberration curves of the zoom lens in the second intermediate focal length state M2. Five solid curves in FIG. 46c are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 46c that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 46d shows lateral chromatic aberration curves of the zoom lens in the telephoto state T. Five solid curves in FIG. 46d are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 46d that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 47a shows optical distortion curves of the zoom lens in the wide-angle state W, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 47a that the differences between imaging deformations and ideal shapes are very small FIG. 47b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 47a. It can be seen from FIG. 47b that optical distortions can be controlled within a range less than or equal to 3%.

FIG. 48a shows optical distortion curves of the zoom lens in the first intermediate focal length state M1, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 48a that the differences between imaging deformations and ideal shapes are very small. FIG. 48b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 48a. It can be seen from FIG. 48b that optical distortions can be controlled within a range less than 0.8%.

FIG. 49a shows optical distortion curves of the zoom lens in the second intermediate focal length state M2, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 49a that the differences between imaging deformations and ideal shapes are very small. FIG. 49b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 49a. It can be seen from FIG. 49b that optical distortions can be controlled within a range less than 1.2%.

FIG. 50a shows optical distortion curves of the zoom lens in the telephoto state T, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 50a that the differences between imaging deformations and ideal shapes are very small FIG. 50b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 50a. It can be seen from FIG. 50b that optical distortions can be controlled within a range less than 1.2%.

FIG. 51 is an example of a seventh zoom lens that may sequentially include the following from an object side to an image side: a first lens group G1 with negative focal power, where a ratio of a focal length f1 of the first lens group G1 to a focal length ft at a telephoto end of the zoom lens is |f1/ft|=0.634; a second lens group G2 with positive focal power, where a ratio of a focal length f2 of the second lens group G2 to the focal length ft at the telephoto end of the zoom lens is |f2/ft|=0.228; a third lens group G3 with negative focal power, where a ratio of a focal length f3 of the third lens group G3 to the focal length ft at the telephoto end of the zoom lens is |f3/ft|=0.171; and a fourth lens group G4 with positive focal power, where a ratio of a focal length f4 of the fourth lens group G4 to the focal length ft at the telephoto end of the zoom lens is |f4/ft|=0.570.

The zoom lens includes 10 lenses with focal power and includes 18 aspheric surfaces in total. The first lens group G1 includes three lenses sequentially distributed from the object side to the image side, and the three lenses are with positive, positive, and negative focal power respectively. The second lens group G2 includes four lenses sequentially distributed from the object side to the image side, and the four lenses are with positive, positive, negative, and positive focal power respectively. The third lens group G3 includes two lenses sequentially distributed from the object side to the image side, and the two lenses are with negative and negative focal power respectively. The fourth lens group G4 includes one lens with positive focal power. The second lens group G2 includes at least one lens with negative focal power, to eliminate an aberration. In addition, the zoom lens further has a stop (not shown in FIG. 51). The stop is located on an object side of the second lens group G2 but is not limited thereto. Alternatively, the stop may be disposed on an image side or an object side of the first lens group G1 or may be disposed on an image side or an object side of the third lens group G3. A maximum aperture diameter of a lens in the first lens group G1, the second lens group G2, and the third lens group G3 is 9 mm.

Subsequently, refer to Table 7a and Table 7b. Table 7a shows a surface curvature, a thickness, a refractive index (nd), and an abbe coefficient (vd) of each lens of the zoom lens shown in FIG. 51 in a wide-angle state. For meanings of the parameters in Table 7a, refer to introduction in a corresponding part in Table 1a. Table 7b shows aspheric coefficients of aspheric surfaces of the lenses.

TABLE 7a

R
Thickness
nd
vd

R1
20.159
d1
1.604
n1
1.54
v1
56.0

R2
−25.554
a1
0.233

R3
86.59
d2
1.8
n2
1.67
v2
19.2

R4
−39.81
a2
0.961

R5
−12.18
d3
0.653
n3
1.54
v3
56.0

R6
5.56
a3
1

R7
6.157
d4
1.8
n4
1.50
v4
81.6

R8
−29.215
a4
0.08

R9
8.331
d5
1.728
n5
1.54
v5
56.0

R10
−41.480
a5
0.08

R11
−67.422
d6
1.332
n6
1.67
v6
19.2

R12
6.435
a6
1.022

R13
10.993
d7
1.558
n7
1.64
v7
23.5

R14
−35.72
a7
2.243

R15
−1.002
d8
1.264
n8
1.54
v8
56.0

R16
9.935
a8
1.1

R17
−10.958
d9
0.61
n9
1.54
v9
56.0

R18
9.073
a9
8.19

R19
15.615
d10
1.428
n10
1.64
v10
23.5

R20
−9.890
a10
0.425

TABLE 7b

Aspheric coefficient

Type
K
A2
A3
A4
A5
A6
A7

R1
Even aspheric
0.00E+00
8.11E−04
1.59E−05
−6.13E−07
3.31E−08
−5.84E−10
9.92E−12

R2
Even aspheric
0.00E+00
2.15E−03
−3.01E−05
3.86E−07
3.86E−08
−1.08E−09
1.493E−11

R3
Even aspheric
0.00E+00
5.02E−05
3.68E−06
3.80E−07
2.01E−09
3.34E−10
0.00E+00

R4
Even aspheric
0.00E+00
−2.84E−04
3.59E−05
−9.78E−07
7.13E−09
2.68E−09
0.00E+00

R5
Even aspheric
0.00E+00
−3.85E−05
−4.76E−05
1.58E−06
7.26E−08
−2.08E−09
−4.06E−11

R6
Even aspheric
0.00E+00
−2.97E−03
2.68E−05
−2.29E−06
3.90E−07
−2.58E−08
5.52E−10

R9
Even aspheric
0.00E+00
−1.04E−03
−3.59E−05
−2.327E−06
−1.38E−07
7.51E−09
0.00E+00

R10
Even aspheric
0.00E+00
−2.01E−04
−5.07E−06
−3.95E−07
−2.33E−07
−7.94E−11
0.00E+00

R11
Even aspheric
0.00E+00
4.34E−04
3.20E−05
1.67E−06
8.74E−08
−2.89E−08
0.00E+00

R12
Even aspheric
0.00E+00
−4.85E−04
1.140E−04
−2.244E−06
3.59E−07
9.38E−09
0.00E+00

R13
Even aspheric
0.00E+00
−2.19E−03
7.53E−05
3.96E−06
−2.15E−06
2.26E−07
0.00E+00

R14
Even aspheric
0.00E+00
−9.73E−04
5.92E−05
4.38E−06
−2.15E−06
2.07E−07
0.00E+00

R15
Even aspheric
0.00E+00
6.23E−03
3.72E−05
3.18E−05
−7.31E−06
3.43E−07
0.00E+00

R16
Even aspheric
0.00E+00
5.77E−03
5.79E−04
2.21E−04
−3.22E−05
3.66E−06
0.00E+00

R17
Even aspheric
0.00E+00
−2.85E−02
5.65E−03
−4.98E−04
−5.64E−06
3.45E−06
0.00E+00

R18
Even aspheric
0.00E+00
−2.49E−02
6.01E−03
−9.69E−04
8.82E−05
−3.86E−06
0.00E+00

R19
Even aspheric
0.00E+00
−2.67E−04
−1.42E−04
3.31E−05
−2.95E−06
1.17E−07
0.00E+00

R20
Even aspheric
0.00E+00
1.35E−05
−2.48E−04
5.82E−05
−5.16E−06
1.89E−07
0.00E+00

In the 18 aspheric surfaces of the zoom lens shown in Table 7b, surface types z of all the even aspheric surfaces may be defined according to, but not limited to, the following aspheric surface formula:

$z = \frac{{cr}^{2}}{1 + \sqrt{1 - {Kc}^{2} r^{2}}} + A_{2} r^{4} + A_{3} r^{6} + A_{4} r^{8} + A_{5} r^{10} + A_{6} r^{12} + A_{7} r^{14},$

where

Because the zoom lens has the 18 aspheric surfaces, the aspheric surfaces may be flexibly designed, and a good aspheric surface type may be designed based on an actual requirement, to improve imaging quality.

A structure of the zoom lens shown in FIG. 51 is used. A ratio |TTL/ft| of a total length TTL of the zoom lens from a surface closest to the object side to the imaging plane to the effective focal length ft at the telephoto end of the zoom lens is 0.904. In view of this, a small total optical length may be used to achieve a long focal length. A ratio |IMH/ft| of a half-image height IMH to the effective focal length ft at the telephoto end of the zoom lens may reach 0.08955.

As shown in FIG. 51, positions of the first lens group G1 and the fourth lens group G4 are fixed relative to the imaging plane, and the second lens group G2 and the third lens group G3 move along an optical axis between the first lens group G1 and the fourth lens group G4. The second lens group G2 serves as a zoom lens group, and the third lens group G3 serves as a compensation lens group, to implement continuous zoom.

FIG. 52 is a zoom process of the zoom lens shown in FIG. 51. The zoom lens has four focal length states: W indicates the wide-angle state, M1 indicates a first intermediate focal length state, M2 indicates a second intermediate focal length state, and T indicates a telephoto state. The wide-angle state T of the zoom lens corresponds to the following relative positions of the lens groups. The third lens group G3 is close to the fourth lens group G4, and the second lens group G2 is close to an object side of the third lens group G3. When the zoom lens zooms from the wide-angle state W to the first intermediate focal length state M1, the second lens group G2 moves towards the first lens group G1, and the third lens group G3 moves towards the second lens group G2. When the zoom lens zooms from the first intermediate focal length state M1 to the second intermediate focal length state M2, the second lens group G2 continues to move towards the first lens group G1, and the third lens group G3 continues to move towards the second lens group G2. When the zoom lens zooms from the second intermediate focal length state M2 to the telephoto state T, the second lens group G2 continues to move towards the first lens group G1, and the third lens group G3 continues to move towards the second lens group G2.

It can be seen from FIG. 52 that when the zoom lens zooms from the wide-angle state W to the telephoto state T, both the second lens group G2 and the third lens group G3 keep moving towards the object side, but a distance between the third lens group G3 and the second lens group G2 first decreases and then increases, to implement continuous zoom. The second lens group G2 serves as a zoom lens group, and a ratio |L1/TTL| of a movement stroke L1 of the second lens group G2 along the optical axis to a total length TTL of the zoom lens from the surface closest to the object side to the imaging plane is 0.26403. The third lens group G3 serves as a compensation lens group, and a ratio |L2/TTL| of a movement stroke L2 of the third lens group G3 along the optical axis to the total length TTL of the zoom lens from the surface closest to the object side to the imaging plane is 0.24389.

Refer to Table 7c, Table 7d, and Table 7e correspondingly. Table 7c shows basic parameters of the zoom lens, and Table 7d shows spacing distances between the lens groups of the zoom lens in the wide-angle state W, the first intermediate focal length state M1, the second intermediate focal length state M2, and the telephoto state T. Table 7e shows chief ray angle values (CRA values) of the zoom lens in different fields of view in the wide-angle state W, the first intermediate focal length state M1, the second intermediate focal length state M2, and the telephoto state T.

TABLE 7c

W
M1
M2
T

Focal length F
11.5 mm

17 mm

24 mm
33.5 mm

F-number
2.38
3.17
3.97
4.83

Half-image
3 mm
3 mm
3 mm
3 mm

height IMH

Half FOV
14.47°
9.80°
7.01°
5.64°

BFL
1.635 mm
1.635 mm
1.635 mm
1.635 mm

TTL
30.3 mm
30.3 mm
30.3 mm
30.3 mm

Designed
650 nm, 610 nm, 555 nm, 510 nm, and 470 nm

wavelength

TABLE 7d

W
M1
M2
T

a3
9.000 mm
6.416 mm
3.730 mm
1.000 mm

a7
1.634 mm
1.350 mm
1.568 mm
2.243 mm

a9
0.800 mm
3.667 mm
6.136 mm
8.190 mm

TABLE 7e

W
M1
M2
T

0
0
0
0
0

0.2
2.33
0.533
−0.41
−0.98

0.4
4.56
0.99
−0.90
−2.04

0.6
6.62
1.31
−1.49
−3.19

0.8
7.80
1.70
−1.96
−4.19

1
8.63
2.34
−2.07
−4.81

Simulation is performed on the zoom lens shown in FIG. 51. The following describes imaging effect of the zoom lens with reference to the accompanying drawings.

FIG. 53a shows axial aberration curves of the zoom lens shown in FIG. 51 in the wide-angle state W. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.4136 mm. It can be seen from FIG. 53a that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.020 mm. In other words, axial aberrations of the zoom lens in the wide-angle state W are controlled within a small range.

FIG. 53b shows axial aberration curves of the zoom lens shown in FIG. 51 in the first intermediate focal length state M1. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.6755 mm. It can be seen from FIG. 53b that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.05 mm. In other words, axial aberrations of the zoom lens in the first intermediate focal length state M1 are controlled within a small range.

FIG. 53c shows axial aberration curves of the zoom lens shown in FIG. 51 in the second intermediate focal length state M2. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 3.0157 mm. It can be seen from FIG. 53c that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.07 mm. In other words, axial aberrations of the zoom lens in the second intermediate focal length state M2 are controlled within a small range.

FIG. 53d shows axial aberration curves of the zoom lens shown in FIG. 51 in the telephoto state T. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 3.4631 mm. It can be seen from FIG. 53d that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.07 mm. In other words, axial aberrations of the zoom lens in the telephoto state T are controlled within a small range.

FIG. 54a shows lateral chromatic aberration curves of the zoom lens in the wide-angle state W. Five solid curves in FIG. 54a are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 54a that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 54b shows lateral chromatic aberration curves of the zoom lens in the first intermediate focal length state M1. Five solid curves in FIG. 54b are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 54b that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 54c shows lateral chromatic aberration curves of the zoom lens in the second intermediate focal length state M2. Five solid curves in FIG. 54c are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 54c that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 54d shows lateral chromatic aberration curves of the zoom lens in the telephoto state T. Five solid curves in FIG. 54d are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 54d that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 55a shows optical distortion curves of the zoom lens in the wide-angle state W, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 55a that the differences between imaging deformations and ideal shapes are very small. FIG. 55b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 55a. It can be seen from FIG. 55b that optical distortions can be controlled within a range less than or equal to 1.2%.

FIG. 56a shows optical distortion curves of the zoom lens in the first intermediate focal length state M1, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 56a that the differences between imaging deformations and ideal shapes are very small. FIG. 56b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 56a. It can be seen from FIG. 56b that optical distortions can be controlled within a range less than 2.5%.

FIG. 57a shows optical distortion curves of the zoom lens in the second intermediate focal length state M2, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 57a that the differences between imaging deformations and ideal shapes are very small. FIG. 57b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 57a. It can be seen from FIG. 57b that optical distortions can be controlled within a range less than 2.0%.

FIG. 58a shows optical distortion curves of the zoom lens in the telephoto state T, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 58a that the differences between imaging deformations and ideal shapes are very small. FIG. 58b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 58a. It can be seen from FIG. 58b that optical distortions can be controlled within a range less than 1.2%.

FIG. 59 is an example of an eighth zoom lens that may sequentially include the following from an object side to an image side: a first lens group G1 with negative focal power, where a ratio of a focal length f1 of the first lens group G1 to a focal length ft at a telephoto end of the zoom lens is |f1/ft|=0.447; a second lens group G2 with positive focal power, where a ratio of a focal length f2 of the second lens group G2 to the focal length ft at the telephoto end of the zoom lens is |f2/ft|=0.217; a third lens group G3 with negative focal power, where a ratio of a focal length f3 of the third lens group G3 to the focal length ft at the telephoto end of the zoom lens is |f3/ft|=0.202; and a fourth lens group G4 with positive focal power, where a ratio of a focal length f4 of the fourth lens group G4 to the focal length ft at the telephoto end of the zoom lens is |f4/ft|=0.881.

The zoom lens includes 10 lenses with focal power and includes 16 aspheric surfaces in total. The first lens group G1 includes two lenses sequentially distributed from the object side to the image side, the two lenses are with positive and negative focal power respectively, and a first lens is a positive meniscus lens with a convex surface that bulges towards the object side. The second lens group G2 includes four lenses sequentially distributed from the object side to the image side, and the four lenses are with positive, positive, negative, and positive focal power respectively. The third lens group G3 includes three lenses sequentially distributed from the object side to the image side, and the three lenses are with negative, positive, and negative focal power respectively. The fourth lens group G4 includes one lens with positive focal power. The second lens group G2 includes at least one lens with negative focal power, to eliminate an aberration. In addition, the zoom lens further has a stop (not shown in FIG. 59). The stop is located on an object side of the second lens group G2 but is not limited thereto. Alternatively, the stop may be disposed on an image side or an object side of the first lens group G1 or may be disposed on an image side or an object side of the third lens group G3. A maximum aperture diameter of a lens in the first lens group G1, the second lens group G2, and the third lens group G3 is 8.168 mm.

Subsequently, refer to Table 8a and Table 8b. Table 8a shows a surface curvature, a thickness, a refractive index (nd), and an abbe coefficient (vd) of each lens of the zoom lens shown in FIG. 59 in a wide-angle state. For meanings of the parameters in Table 8a, refer to introduction in a corresponding part in Table 1a. Table 8b shows aspheric coefficients of aspheric surfaces of the lenses.

TABLE 8a

R
Thickness
nd
vd

R1
7.296
d1
1.8
n1
1.64
v1
23.5

R2
8.979
a1
1.383

R3
−12.607
d2
0.4
n2
1.60
v2
60.6

R4
10.913
a2
8.941

R5
5.738
d3
1.44
n3
1.54
v3
56.0

R6
−103.70
a3
1.31

R7
8.216
d4
1.8
n4
1.54
v4
56.0

R8
−10.133
a4
0.08

R9
−21.748
d5
0.4
n5
1.67
v5
19.2

R10
8.099
a5
1.352

R11
6.916
d6
0.553
n6
1.67
v6
19.2

R12
11.138
a6
1.554

R13
10.452
d7
0.4
n7
1.85
v7
23.8

R14
4.153
a7
2.589

R15
−57.542
d8
1.02
n8
1.67
v8
19.2

R16
−6.093
a8
0.532

R17
−4.551
d9
0.4
n9
1.54
v9
56.0

R18
496.018
a9
0.802

R19
−320.81
d10
0.958
n10
1.67
v10
19.2

R20
−8.350
a10
0.08

TABLE 8b

Aspheric coefficient

Type
K
A2
A3
A4
A5
A6
A7

R1
Even aspheric
0.00E+00
−2.36E−04
−1.08E−06
1.36E−07
−4.01E−09
4.81E−10
0.00E+00

R2
Even aspheric
0.00E+00
−5.57E−04
1.30E−07
−3.74E−07
4.69E−08
−7.51E−10
0.00E+00

R5
Even aspheric
0.00E+00
−1.99E−04
−1.22E−05
−1.19E−06
3.95E−08
−1.40E−09
0.00E+00

R6
Even aspheric
0.00E+00
1.26E−04
−1.12E−05
2.44E−08
4.67E−08
−1.05E−09
0.00E+00

R7
Even aspheric
0.00E+00
−3.05E−04
1.61E−06
1.16E−06
5.73E−08
9.29E−09
0.00E+00

R8
Even aspheric
0.00E+00
6.30E−04
−2.89E−06
−4.10E−07
1.37E−07
−4.05E−09
0.00E+00

R9
Even aspheric
0.00E+00
1.50E−05
7.36E−06
1.98E−06
−1.78E−07
−8.05E−09
0.00E+00

R10
Even aspheric
0.00E+00
1.47E−03
1.16E−04
8.37E−06
−5.31E−07
8.38E−08
0.00E+00

R11
Even aspheric
0.00E+00
8.69E−04
1.68E−04
−1.14E−05
1.34E−08
−1.85E−07
0.00E+00

R12
Even aspheric
0.00E+00
6.73E−04
1.15E−04
−2.88E−06
−2.66E−06
−1.08E−08
0.00E+00

R15
Even aspheric
0.00E+00
1.64E−03
3.45E−04
−1.02E−04
2.03E−05
−8.31E−07
0.00E+00

R16
Even aspheric
0.00E+00
3.62E−03
1.31E−04
−5.53E−05
5.01E−06
6.66E−07
0.00E+00

R17
Even aspheric
0.00E+00
1.46E−03
2.31E−04
−4.70E−05
−6.06E−06
5.10E−07
5.23E−08

R18
Even aspheric
0.00E+00
−3.53E−03
4.22E−04
−4.47E−05
−2.01E−06
3.20E−07
1.63E−09

R19
Even aspheric
0.00E+00
−1.63E−03
−4.29E−04
2.03E−06
4.69E−06
−4.50E−07
0.00E+00

R20
Even aspheric
0.00E+00
−1.34E−03
−4.68E−04
2.77E−05
1.61E−06
−2.62E−07
0.00E+00

In the 16 aspheric surfaces of the zoom lens shown in Table 8b, surface types z of all the even aspheric surfaces may be defined according to, but not limited to, the following aspheric surface formula:

$z = \frac{{cr}^{2}}{1 + \sqrt{1 - {Kc}^{2} r^{2}}} + A_{2} r^{4} + A_{3} r^{6} + A_{4} r^{8} + A_{5} r^{10} + A_{6} r^{12} + A_{7} r^{14},$

where

A structure of the zoom lens shown in FIG. 59 is used. A ratio |TTL/ft| of a total length TTL of the zoom lens from a surface closest to the object side to the imaging plane to the effective focal length ft at the telephoto end of the zoom lens is 0.881. In view of this, a small total optical length may be used to achieve a long focal length. A ratio |IMH/ft| of a half-image height IMH to the effective focal length ft at the telephoto end of the zoom lens may reach 0.08955.

As shown in FIG. 59, positions of the first lens group G1 and the fourth lens group G4 are fixed relative to the imaging plane, and the second lens group G2 and the third lens group G3 move along an optical axis between the first lens group G1 and the fourth lens group G4. The second lens group G2 serves as a zoom lens group, and the third lens group G3 serves as a compensation lens group, to implement continuous zoom.

FIG. 60 is a zoom process of the zoom lens shown in FIG. 59. The zoom lens has four focal length states: W indicates the wide-angle state, M1 indicates a first intermediate focal length state, M2 indicates a second intermediate focal length state, and T indicates a telephoto state. The wide-angle state T of the zoom lens corresponds to the following relative positions of the lens groups. The third lens group G3 is close to the fourth lens group G4, and the second lens group G2 is close to an object side of the third lens group G3. When the zoom lens zooms from the wide-angle state W to the first intermediate focal length state M1, the second lens group G2 moves towards the first lens group G1, and the third lens group G3 moves towards the second lens group G2. When the zoom lens zooms from the first intermediate focal length state M1 to the second intermediate focal length state M2, the second lens group G2 continues to move towards the first lens group G1, and the third lens group G3 continues to move towards the second lens group G2. When the zoom lens zooms from the second intermediate focal length state M2 to the telephoto state T, the second lens group G2 continues to move towards the first lens group G1, and the third lens group G3 continues to move towards the second lens group G2.

It can be seen from FIG. 60 that when the zoom lens zooms from the wide-angle state W to the telephoto state T, both the second lens group G2 and the third lens group G3 keep moving towards the object side, but a distance between the third lens group G3 and the second lens group G2 first decreases and then increases, to implement continuous zoom. The second lens group G2 serves as a zoom lens group, and a ratio |L1/TTL| of a movement stroke L1 of the second lens group G2 along the optical axis to a total length TTL of the zoom lens from the surface closest to the object side to the imaging plane is 0.26919. The third lens group G3 serves as a compensation lens group, and a ratio |L2/TTL| of a movement stroke L2 of the third lens group G3 along the optical axis to the total length TTL of the zoom lens from the surface closest to the object side to the imaging plane is 0.18505.

Refer to Table 8c, Table 8d, and Table 8e correspondingly. Table 8c shows basic parameters of the zoom lens, and Table 8d shows spacing distances between the lens groups of the zoom lens in the wide-angle state W, the first intermediate focal length state M1, the second intermediate focal length state M2, and the telephoto state T. Table 8e shows chief ray angle values (CRA values) of the zoom lens in different fields of view in the wide-angle state W, the first intermediate focal length state M1, the second intermediate focal length state M2, and the telephoto state T.

TABLE 8c

W
M1
M2
T

Focal length F
11.5 mm

17 mm

24 mm
33.5 mm

F-number
2.82
3.63
4.43
5.26

Half-image
3 mm
3 mm
3 mm
3 mm

height IMH

Half FOV
15.1°
10.1°
7.11°
5.08°

BFL
1.79 mm
1.79 mm
1.79 mm
1.79 mm

TTL
29.5 mm
29.5 mm
29.5 mm
29.5 mm

Designed
650 nm, 610 nm, 555 nm, 510 nm, and 470 nm

wavelength

TABLE 8d

W
M1
M2
T

a2
8.94 mm
6.11 mm
3.48 mm
1.00 mm

a6
1.55 mm
1.69 mm
2.46 mm
4.04 mm

a9
0.802 mm
3.49 mm
5.36 mm
6.26 mm

TABLE 8e

W
M1
M2
T

0
0.00
0.00
0.00
0.00

0.2
1.51
0.51
0.01
−0.23

0.4
2.88
0.93
−0.07
−0.53

0.6
3.98
1.19
−0.26
−0.94

0.8
5.11
1.76
−0.03
−0.89

1
6.83
3.37
1.38
0.41

Simulation is performed on the zoom lens shown in FIG. 59. The following describes imaging effect of the zoom lens with reference to the accompanying drawings.

FIG. 61a shows axial aberration curves of the zoom lens shown in FIG. 59 in the wide-angle state W. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.0371 mm. It can be seen from FIG. 61a that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.03 mm. In other words, axial aberrations of the zoom lens in the wide-angle state W are controlled within a small range.

FIG. 61b shows axial aberration curves of the zoom lens shown in FIG. 59 in the first intermediate focal length state M1. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.7073 mm. It can be seen from FIG. 61b that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.07 mm. In other words, axial aberrations of the zoom lens in the first intermediate focal length state M1 are controlled within a small range.

FIG. 61c shows axial aberration curves of the zoom lens shown in FIG. 59 in the second intermediate focal length state M2. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.7073 mm. It can be seen from FIG. 61c that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.07 mm. In other words, axial aberrations of the zoom lens in the second intermediate focal length state M2 are controlled within a small range.

FIG. 61d shows axial aberration curves of the zoom lens shown in FIG. 59 in the telephoto state T. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 3.1842 mm. It can be seen from FIG. 61d that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.06 mm. In other words, axial aberrations of the zoom lens in the telephoto state T are controlled within a small range.

FIG. 62a shows lateral chromatic aberration curves of the zoom lens in the wide-angle state W. Five solid curves in FIG. 62a are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 62a that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 62b shows lateral chromatic aberration curves of the zoom lens in the first intermediate focal length state M1. Five solid curves in FIG. 62b are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 62b that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 62c shows lateral chromatic aberration curves of the zoom lens in the second intermediate focal length state M2. Five solid curves in FIG. 62c are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 62c that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 62d shows lateral chromatic aberration curves of the zoom lens in the telephoto state T. Five solid curves in FIG. 62d are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 62d that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 63a shows optical distortion curves of the zoom lens in the wide-angle state W, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 63a that the differences between imaging deformations and ideal shapes are very small. FIG. 63b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 63a. It can be seen from FIG. 63b that optical distortions can be controlled within a range less than or equal to 3%.

FIG. 64a shows optical distortion curves of the zoom lens in the first intermediate focal length state M1, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 64a that the differences between imaging deformations and ideal shapes are very small. FIG. 64b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 64a. It can be seen from FIG. 64b that optical distortions can be controlled within a range less than 1.2%.

FIG. 65a shows optical distortion curves of the zoom lens in the second intermediate focal length state M2, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 65a that the differences between imaging deformations and ideal shapes are very small. FIG. 65b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 65a. It can be seen from FIG. 65b that optical distortions can be controlled within a range less than or equal to 0.6%.

FIG. 66a shows optical distortion curves of the zoom lens in the telephoto state T, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 66a that the differences between imaging deformations and ideal shapes are very small. FIG. 66b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 66a. It can be seen from FIG. 66b that optical distortions can be controlled within a range less than 0.7%.

FIG. 67 is an example of a ninth zoom lens that may sequentially include the following from an object side to an image side: a first lens group G1 with negative focal power, where a ratio of a focal length f1 of the first lens group G1 to a focal length ft at a telephoto end of the zoom lens is |f1/ft|=0.71; a second lens group G2 with positive focal power, where a ratio of a focal length f2 of the second lens group G2 to the focal length ft at the telephoto end of the zoom lens is |f2/ft|=0.23; a third lens group G3 with negative focal power, where a ratio of a focal length f3 of the third lens group G3 to the focal length ft at the telephoto end of the zoom lens is |f3/ft|=0.335; and a fourth lens group G4 with positive focal power, where a ratio of a focal length f4 of the fourth lens group G4 to the focal length ft at the telephoto end of the zoom lens is |f4/ft|=0.384.

The zoom lens includes eight lenses with focal power and includes 16 aspheric surfaces in total. The first lens group G1 includes two lenses sequentially distributed from the object side to the image side, the two lenses are with positive and negative focal power respectively, and a first lens is a positive meniscus lens with a convex surface that bulges towards the object side. The second lens group G2 includes two lenses sequentially distributed from the object side to the image side, and the two lenses are with positive and negative focal power respectively. The third lens group G3 includes three lenses sequentially distributed from the object side to the image side, and the three lenses are with positive, negative, and positive focal power respectively. The fourth lens group G4 includes one lens with positive focal power. The second lens group G2 includes at least one lens with negative focal power, to eliminate an aberration. In addition, the zoom lens further has a stop (not shown in FIG. 67). The stop is located on an object side of the second lens group G2 but is not limited thereto. Alternatively, the stop may be disposed on an image side or an object side of the first lens group G1 or may be disposed on an image side or an object side of the third lens group G3. A maximum aperture diameter of a lens in the first lens group G1, the second lens group G2, and the third lens group G3 is 7.902 mm.

Subsequently, refer to Table 9a and Table 9b. Table 9a shows a surface curvature, a thickness, a refractive index (nd), and an abbe coefficient (vd) of each lens of the zoom lens shown in FIG. 67 in a wide-angle state. For meanings of the parameters in Table 9a, refer to introduction in a corresponding part in Table 1a. Table 9b shows aspheric coefficients of aspheric surfaces of the lenses.

TABLE 9a

R
Thickness

nd

vd

R1
5.625
d1
2.928
n1
1.59
v1
67.0

R2
7.037
a1
0.769

R3
20.331
d2
0.500
n2
1.54
v2
56.0

R4
3.873
a2
6.443

R5
4.174
d3
2.766
n3
1.54
v3
56.0

R6
−6.985
a3
0.100

R7
−18.088
d4
0.569
n4
1.66
v4
20.4

R8
32.926
a4
2.384

R9
−10.125
d5
2.372
n5
1.66
v5
20.4

R10
−7.917
a5
0.520

R11
−3.514
d6
0.725
n6
1.54
v6
56.0

R12
−15.693
a6
1.426

R13
−4.707
d7
0.566
n7
1.54
v7
56.0

R14
−5.087
a7
1.941

R15
−54.917
d8
1.794
n8
1.54
v8
56.0

R16
−5.537
a8
0.100

R17
Infinity
d9
0.209
n9
1.52
v9
64.2

R18
Infinity
a9
1.300

TABLE 9b

Aspheric coefficient

Type
K
A2
A3
A4
A5
A6
A7
A8

R1
Even aspheric
0.00
1.03E−03
−6.84E−06
−4.19E−07
−6.76E−08
0.00E+00
0.00E+00
0.00E+00

R2
Even aspheric
0.00
1.14E−02
−2.47E−05
4.13E−06
−8.99E−07
−8.88E−08
0.00E+00
0.00E+00

R3
Even aspheric
0.00
8.31E−03
−1.48E−03
1.63E−04
−1.49E−05
7.47E−07
−1.03E−08
−1.36E−09

R4
Even aspheric
0.00
−4.59E−03
−1.14E−03
1.26E−04
−8.17E−06
−6.41E−08
1.18E−08
3.79E−10

R5
Even aspheric
0.00
−1.05E−05
8.92E−05
−5.35E−06
1.25E−06
−2.13E−08
−1.70E−09
1.05E−09

R6
Even aspheric
0.00
3.78E−03
−2.02E−04
8.00E−06
5.57E−06
1.03E−07
8.37E−09
−6.64E−09

R7
Even aspheric
0.00
−4.43E−03
1.99E−04
−2.30E−05
1.83E−05
−1.40E−06
−8.84E−09
−8.61E−09

R8
Even aspheric
0.00
−4.33E−03
4.80E−04
3.26E−05
3.51E−06
−2.42E−07
−3.55E−08
−2.49E−10

R9
Even aspheric
0.00
4.88E−03
−3.27E−04
5.46E−05
2.13E−06
−9.29E−07
2.92E−08
3.29E−16

R10
Even aspheric
0.00
8.64E−03
−8.80E−04
1.32E−04
−4.60E−06
5.79E−09
0.00E+00
0.00E+00

R11
Even aspheric
0.00
1.72E−02
−2.10E−03
2.57E−04
−2.64E−05
1.62E−07
0.00E+00
0.00E+00

R12
Even aspheric
0.00
6.48E−03
3.94E−04
2.06E−06
−1.88E−05
1.01E−06
1.10E−08
−1.91E−11

R13
Even aspheric
0.00
−1.59E−02
3.12E−03
−2.41E−05
−4.07E−05
2.01E−06
−2.06E−08
5.47E−12

R14
Even aspheric
0.00
−1.24E−02
1.89E−03
−9.65E−05
−3.76E−06
−3.36E−07
−6.91E−10
2.19E−10

R15
Even aspheric
0.00
1.36E−04
3.37E−04
−8.40E−05
8.07E−06
−2.99E−07
2.69E−09
5.54E−11

R16
Even aspheric
0.00
5.81E−03
−7.66E−05
−4.99E−05
2.71E−06
2.18E−07
−2.02E−08
4.56E−10

In the 16 aspheric surfaces of the zoom lens shown in Table 9b, surface types z of all the even aspheric surfaces may be defined according to, but not limited to, the following aspheric surface formula:

$z = \frac{{cr}^{2}}{1 + \sqrt{1 - {Kc}^{2} r^{2}}} + A_{2} r^{4} + A_{3} r^{6} + A_{4} r^{8} + A_{5} r^{10} + A_{6} r^{12} + A_{7} r^{14} + A_{8} r^{1 6},$

where

A structure of the zoom lens shown in FIG. 67 is used. A ratio |TTL/ft| of a total length TTL of the zoom lens from a surface closest to the object side to the imaging plane to the effective focal length ft at the telephoto end of the zoom lens is 0.95. In view of this, a small total optical length may be used to achieve a long focal length. A ratio |IMH/ft| of a half-image height IMH to the effective focal length ft at the telephoto end of the zoom lens may reach 0.144.

As shown in FIG. 67, positions of the first lens group G1 and the fourth lens group G4 are fixed relative to the imaging plane, and the second lens group G2 and the third lens group G3 move along an optical axis between the first lens group G1 and the fourth lens group G4. The second lens group G2 serves as a zoom lens group, and the third lens group G3 serves as a compensation lens group, to implement continuous zoom.

FIG. 68 is a zoom process of the zoom lens shown in FIG. 67. The zoom lens has four focal length states: W indicates the wide-angle state, M1 indicates a first intermediate focal length state, M2 indicates a second intermediate focal length state, and T indicates a telephoto state. The wide-angle state T of the zoom lens corresponds to the following relative positions of the lens groups. The third lens group G3 is close to the fourth lens group G4, and the second lens group G2 is close to an object side of the third lens group G3. When the zoom lens zooms from the wide-angle state W to the first intermediate focal length state M1, the second lens group G2 moves towards the first lens group G1, and the third lens group G3 moves towards the second lens group G2. When the zoom lens zooms from the first intermediate focal length state M1 to the second intermediate focal length state M2, the second lens group G2 continues to move towards the first lens group G1, and the third lens group G3 continues to move towards the second lens group G2. When the zoom lens zooms from the second intermediate focal length state M2 to the telephoto state T, the second lens group G2 continues to move towards the first lens group G1, and the third lens group G3 continues to move towards the second lens group G2.

It can be seen from FIG. 68 that when the zoom lens zooms from the wide-angle state W to the telephoto state T, both the second lens group G2 and the third lens group G3 keep moving towards the object side, but a distance between the third lens group G3 and the second lens group G2 first decreases and then increases, to implement continuous zoom. The second lens group G2 serves as a zoom lens group, and a ratio |L1/TTL| of a movement stroke L1 of the second lens group G2 along the optical axis to a total length TTL of the zoom lens from the surface closest to the object side to the imaging plane is 0.2022. The third lens group G3 serves as a compensation lens group, and a ratio |L2/TTL| of a movement stroke L2 of the third lens group G3 along the optical axis to the total length TTL of the zoom lens from the surface closest to the object side to the imaging plane is 0.1845.

Refer to Table 9c, Table 9d, and Table 9e correspondingly. Table 9c shows basic parameters of the zoom lens, and Table 9d shows spacing distances between the lens groups of the zoom lens in the wide-angle state W, the first intermediate focal length state M1, the second intermediate focal length state M2, and the telephoto state T.

TABLE 9c

W
M1
M2
T

Focal length F (mm)
14.600
18.000
23.999
28.998

F-number
3.348
3.826
4.538
5.052

Half-image
4.190
4.190
4.190
4.190

height IMH (mm)

Half FOV (°)
16.155
12.989
9.719
8.060

BFL (mm)
1.609
1.609
1.609
1.609

TTL (mm)
27.412
27.412
27.412
27.412

Designed
650 nm, 610 nm, 555 nm, 510 nm, and 470 nm

wavelength

TABLE 9d

W
M1
M2
T

a2
6.443 mm
4.753 mm
2.402 mm
0.900 mm

a4
2.384 mm
2.276 mm
2.485 mm
2.868 mm

a7
1.941 mm
3.740 mm
5.882 mm
7.000 mm

Simulation is performed on the zoom lens shown in FIG. 67. The following describes imaging effect of the zoom lens with reference to the accompanying drawings.

FIG. 69a shows axial aberration curves of the zoom lens shown in FIG. 67 in the wide-angle state W. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.2614 mm. It can be seen from FIG. 69a that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.06 mm. In other words, axial aberrations of the zoom lens in the wide-angle state W are controlled within a small range.

FIG. 69b shows axial aberration curves of the zoom lens shown in FIG. 67 in the first intermediate focal length state M1. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.4463 mm. It can be seen from FIG. 69b that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.04 mm. In other words, axial aberrations of the zoom lens in the first intermediate focal length state M1 are controlled within a small range.

FIG. 69c shows axial aberration curves of the zoom lens shown in FIG. 67 in the second intermediate focal length state M2. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 2.7589 mm. It can be seen from FIG. 69c that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.06 mm. In other words, axial aberrations of the zoom lens in the second intermediate focal length state M2 are controlled within a small range.

FIG. 69d shows axial aberration curves of the zoom lens shown in FIG. 67 in the telephoto state T. Five curves respectively indicate simulation results of light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm at focus depth positions when a half-aperture diameter is 3.0036 mm. It can be seen from FIG. 69d that, at any normalized aperture coordinate, a difference between defocus amounts of curves corresponding to every two different wavelengths is less than 0.10 mm. In other words, axial aberrations of the zoom lens in the telephoto state T are controlled within a small range.

FIG. 70a shows lateral chromatic aberration curves of the zoom lens in the wide-angle state W. Five solid curves in FIG. 70a are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 70a that lateral chromatic aberrations of five light rays are basically within the diffraction limit range.

FIG. 70b shows lateral chromatic aberration curves of the zoom lens in the first intermediate focal length state M1. Five solid curves in FIG. 70b are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 70b that lateral chromatic aberrations of five light rays are basically within the diffraction limit range.

FIG. 70c shows lateral chromatic aberration curves of the zoom lens in the second intermediate focal length state M2. Five solid curves in FIG. 70c are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 70c that lateral chromatic aberrations of five light rays are all within the diffraction limit range.

FIG. 70d shows lateral chromatic aberration curves of the zoom lens in the telephoto state T. Five solid curves in FIG. 70d are respectively simulation curves corresponding to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A maximum field of view is 3.0000 mm Dotted lines indicate a diffraction limit range. It can be seen from FIG. 70d that lateral chromatic aberrations of five light rays are basically within the diffraction limit range.

FIG. 71a shows optical distortion curves of the zoom lens in the wide-angle state W, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 71a that the differences between imaging deformations and ideal shapes are very small. FIG. 71b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 71a. It can be seen from FIG. 71b that optical distortions can be controlled within a range less than or equal to 3%.

FIG. 72a shows optical distortion curves of the zoom lens in the first intermediate focal length state M1, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 72a that the differences between imaging deformations and ideal shapes are very small. FIG. 72b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 72a. It can be seen from FIG. 72b that optical distortions can be controlled within a range less than 2.0%.

FIG. 73a shows optical distortion curves of the zoom lens in the second intermediate focal length state M2, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 73a that the differences between imaging deformations and ideal shapes are very small. FIG. 73b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 73a. It can be seen from FIG. 73b that optical distortions can be controlled within a range less than or equal to 3.0%.

FIG. 74a shows optical distortion curves of the zoom lens in the telephoto state T, indicating differences between imaging deformations and ideal shapes. Five solid curves respectively correspond to colored light with wavelengths of 650 nm, 610 nm, 555 nm, 510 nm, and 470 nm. A dotted curve corresponding to each solid curve is an ideal shape corresponding to each light ray. It can be seen from FIG. 74a that the differences between imaging deformations and ideal shapes are very small. FIG. 74b is obtained by calculating percentages of imaging deformations to ideal shapes of the light rays in FIG. 74a. It can be seen from FIG. 74b that optical distortions can be controlled within a range less than 3.0%.

According to the five embodiments provided in FIG. 35 to FIG. 74b, a case in which the zoom lens includes four lens groups: the first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens group G4 is described above as an example. A form of the zoom lens includes the form of four lens groups. However, this is not limited to the foregoing five embodiments.

A ratio of a focal length of each lens groups to the focal length ft at the telephoto end of the zoom lens is not limited to the values in the embodiments provided in FIG. 35 to FIG. 74b. Continuous zoom can be implemented as long as the focal length of each lens group and the focal length at the telephoto end of the zoom lens meet the following ratio relationship: For example, the focal length f1 of the first lens group G1 and the focal length ft at the telephoto end of the zoom lens meet 0.2≤|f1/ft|≤0.9, the focal length f2 of the second lens group G2 and ft meet 0.10≤|f2/ft|≤0.6, and the focal length f3 of the third lens group G3 and ft meet 0.10≤|f3/ft|≤0.7.

A quantity of lenses included in each lens group in the five embodiments provided in FIG. 35 to FIG. 74b is merely an example. The quantity of lenses in each lens group is not limited for the zoom lens provided in the embodiments, and only a total quantity N of lenses in the first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens group G4 is limited. For example, each lens group may include one, two, or more lenses. The total quantity N of lenses in the first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens group G4 needs to meet 7≤N≤13, to ensure that the zoom lens has a good continuous zoom capability and imaging effect. For example, N may be different positive integers such as 7, 8, 9, 10, 11, or 13. In addition, all lenses included in the first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens group G4 meet N≤quantity of aspheric surfaces≤2N, where N is the total quantity of lenses in the first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens group G4, and the quantity of aspheric surfaces is a quantity of aspheric surfaces of all lenses included in the first lens group G1, the second lens group G2, the third lens group G3, and the fourth lens group G4. For example, the quantity of aspheric surfaces may be N, 1.2N, 1.5N, 1.7N, or 2N. The aspheric surface is a transparent surface of a lens.

In the five embodiments provided in FIG. 35 to FIG. 74b, in a sliding process of the second lens group G2 and the third lens group G3, the ratio |L1/TTL| of the movement stroke L1 of the second lens group G2 along the optical axis to the total length TTL of the zoom lens from the surface closest to the object side to the imaging plane, and the ratio |L2/TTL| of the movement stroke L2 of the third lens group G3 along the optical axis to the total length TTL of the zoom lens from the surface closest to the object side to the imaging plane are merely examples. Only the ratio of the movement stroke L1 of the second lens group G2 along the optical axis to the total length TTL of the zoom lens from the surface closest to the object side to the imaging plane needs to meet 0.12≤|L1/TTL|≤0.35. For example, the ratio may be 0.12, 0.16, 0.19, 0.20, 0.25, 0.30, 0.33, or 0.35. The ratio of the movement stroke L2 of the third lens group G3 along the optical axis to the total length TTL of the zoom lens from the surface closest to the object side to the imaging plane meets 0.08≤|L2/TTL|≤0.35. For example, the ratio may be 0.08, 0.12, 0.16, 0.19, 0.20, 0.25, 0.30, 0.33, or 0.35. In other words, the second lens group G2 and the third lens group G3 can cooperate with each other to achieve continuous zoom.

After the zoom lens of the foregoing structure is used, the ratio |TTL/ft| of the total length TTL of the zoom lens from the surface closest to the object side to the imaging plane to the effective focal length ft at the telephoto end of the zoom lens meets 0.8≤|TTL/ft|≤1.2. This helps achieve a long focal length by using a short total optical length. The ratio |IMH/ft| of the half-image height IMH to the effective focal length ft at the telephoto end of the zoom lens meets 0.02≤|IMH/ft|≤0.20. For example, the ratio may be 0.02, 0.05, 0.07, 0.12, 0.15, 0.18, or 0.20. The effective focal length ft at the telephoto end of the zoom lens and an effective focal length fw of the wide-angle end of the zoom lens meet 1≤≤3.7. For example, the ratio may be 1, 1.2, 1.6, 1.7, 1.9, 2.2, 2.5, 2.8, 3, 3.3, or 3.7, to obtain better imaging quality during continuous zoom.

It can be understood from structures and simulation effect of the first zoom lens, the second zoom lens, the third zoom lens, the fourth zoom lens, the fifth zoom lens, the sixth zoom lens, the seventh zoom lens, the eighth zoom lens, and the ninth zoom lens that are described above that the zoom lens provided in the embodiments can implement continuous zoom, and an object distance of the zoom lens ranges from infinity to 40 mm. The object distance is a distance from an object to a surface of an object side of a first lens in the first lens group G1 of the zoom lens. It can be understood from simulation results that the zoom lens obtains better imaging quality than conventional hybrid optical zoom in a zoom process. In addition, a difference between a chief ray angle when the zoom lens is in the wide-angle state W and a chief ray angle when the zoom lens is in the telephoto state T is less than or equal to 6°. For example, the difference is 0.1°, 1°, 1.2°, 1.8°, 1.9°, 2.2°, 2.5°, 2.8°, 3.2°, 3.5°, 4°, 4.4°, 4.8°, 5.0°, 5.5°, or 6°.

FIG. 75 shows another zoom lens according to an embodiment. A manner of disposing a lens group of the zoom lens is not limited to the manner in FIG. 75. For details, refer to the foregoing embodiments. In addition, the zoom lens further includes a mirror reflector 20 located on an object side of a first lens group G1, to reflect a light ray to the first lens group G1. For example, an included angle between a mirror surface of the mirror reflector 20 and an optical axis of the zoom lens may be 45°, or the included angle may be adjusted as required. This can implement periscope photographing, so that both a position and an angle for placing the zoom lens are more flexible. For example, an optical axis direction of the zoom lens may be parallel to a surface of a mobile phone screen.

FIG. 76 shows an application scenario of the zoom lens in a mobile phone. When the zoom lens 300 is of a periscope type, an arrangement direction of a lens group 301 in the zoom lens 300 may be parallel to a length direction of a housing 400 of the mobile phone. The lens group 301 is disposed between the housing 400 of the mobile phone and a middle frame 500. It should be understood that FIG. 76 is only an example of a position and a manner of disposing the lens group 301, and the lens group 301 in FIG. 76 does not indicate an actual quantity of lenses of the lens group 301. It can be seen from FIG. 76 that when the zoom lens is of a periscope type, impact on a thickness of the mobile phone can be reduced.

In addition, as shown in FIG. 77, the mirror reflector 20 in FIG. 75 may be replaced with a prism 30. The prism 30 may be a triangular prism. A surface of the prism 30 is used as a reflection surface. The reflection surface and the optical axis of the zoom lens form an angle of 45 degrees, and the angle may also be properly adjusted. Still refer to FIG. 77. For example, a light ray vertically passes through an incident surface of the prism 30, strikes the reflection surface of the prism 30, and is reflected to an emergent surface of the prism 30. The light ray vertically passes through the emergent surface and strikes the first lens group G1. A shape and an angle for placing the prism are not limited to the foregoing form, provided that an external light ray can be deflected to the first lens group G1.

An embodiment may further provide a camera module. The camera module includes a camera chip and the zoom lens provided in any one of the foregoing embodiments. A light ray passes through the zoom lens and strikes the camera chip. The camera module has a housing, the camera chip is fixed in the housing, and the zoom lens is also disposed in the housing. An existing known structure may be used for the housing and the chip of the camera module, and details are not described herein. The zoom lens implements continuous zoom of the zoom lens by using the second lens group as a zoom lens group and using the third lens group as a compensation lens group and by cooperating with the fixed first lens group. This can improve photographing quality of the zoom lens.

An embodiment may further provide a mobile terminal. The mobile terminal may be a mobile phone, a tablet computer, or the like. The mobile terminal includes a housing, and the zoom lens provided in any one of the foregoing embodiments and disposed in the housing. The periscope zoom lens shown in FIG. 76 is disposed in the mobile phone. Also refer to the zoom lens shown in FIG. 4. The zoom lens implements continuous zoom of the zoom lens by using one fixed lens group and two movable lens groups in cooperation with each other, and by using the disposed second lens group and the third lens group. This can improve photographing quality of the zoom lens.

The foregoing descriptions are merely implementations and are not intended to limit the scope of the embodiments. Any variation or replacement readily figured out by a person skilled in the art shall fall within the scope of the embodiments.

	Number	Date	Country
Parent	PCT/CN2020/114566	Sep 2020	US
Child	17896276		US

ZOOM LENS, CAMERA MODULE, AND MOBILE TERMINAL

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