This application claims the benefit of Taiwan application Serial No. 105109875, filed Mar. 29, 2016, the subject matter of which is incorporated herein by reference.
The invention relates to an optical lens, and more particularly to an optical lens which is light and thin, small in size, excellent in image quality and wide in viewing angle.
Since hand-held electronic devices with image-capturing function rise and users often carry the hand-held electronic devices to the outdoors for photographing in recent years, the need for an optical lens which is light and thin, small in size and wide in viewing angle has been increased.
Nowadays, the optical systems require both compact length and high performance, so that the ratio of full-length to focal length is reduced. In prior art, the optical lens employs two lenses to capture images. However, the optical lens having only two lenses cannot meet the requirement of high pixel and high optical performance, and can only be matched with a smaller photosensitive element, hereby failing to obtain an image with higher pixel.
Therefore, it is in need to provide a novel optical lens to achieve an optical lens which is light and thin, small in size, excellent in image quality and wide in viewing angle at the same time in the condition that the cost is under control.
The invention relates to an optical lens having reduced size and good image quality.
According to one embodiment the present invention, an optical lens is provided. The optical lens includes, in order from an object side to an image-forming side, a first lens having negative refractive power, a second lens having negative refractive power, a third lens having refractive power and having an Abbe number Vd3, a cemented lens having refractive power, and a fourth lens having refractive power and having an Abbe number Vd4, wherein 15≦Vd3 and/or Vd3≦30, and 60≦Vd4 and/or Vd4≦85.
According to another embodiment the present invention, an optical lens is provided. The optical lens includes, in order from an object side to an image-forming side, a first lens having negative refractive power, a second lens having refractive power, a third lens being a biconvex lens and having an Abbe number Vd3, a cemented lens having refractive power, and a fourth lens being a biconvex lens and having an Abbe number Vd4, wherein 15≦Vd3 and/or Vd3≦30, and 60≦Vd4 and/or Vd4≦85.
The above and other aspects of the invention will become better understood with regard to the following detailed description of the preferred but non-limiting embodiment(s). The following description is made with reference to the accompanying drawings.
The embodiments of the present invention are described in details with reference to the accompanying drawings. While the invention will be described in conjunction with these specific embodiments, it will be understood that it is not intended to limit the invention to these embodiments. On the contrary, it is intended to cover alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may be practiced without some or all of these specific details. In other instances, well-known components and process operations are not described in detail in order not to unnecessarily obscure the present invention. Identical or similar elements of the embodiments are designated with the same or similar reference numerals. While drawings are illustrated in details, it is appreciated that the quantity or sizes of the disclosed components may be greater or less than that disclosed, except expressly restricting the amount or the sizes of the components.
In one embodiment, the optical lens OL1, in order from an object side to an image-forming side, may include a first lens group G1 and a second lens group G2. The first lens group G1 may have negative refractive power, and the second lens group G2 may have positive refractive power.
In one embodiment, the first lens group G1 at least includes a plurality of lenses, and the second lens group G2 at least includes a cemented lens and a lens. In one embodiment, the first lens group G1 may include three or more than three lenses. In another embodiment, the cemented lens may have two or more than two lenses, but the present invention is not limited thereto. In addition, each lens may have refractive power respectively, such as positive refractive power or negative refractive power.
As shown in
In one embodiment, the third lens L3 has an Abbe number Vd3, and Vd3 may satisfy at least one of the following conditions: 15≦Vd3, 16≦Vd3, 17.3≦Vd3, Vd3≦26, Vd3≦28, Vd3≦30, 15≦Vd3≦26, 16≦Vd3≦26, 17.35≦Vd3≦26, 15≦Vd3≦28, 16≦Vd3≦28, 17.3≦Vd3≦28, 15≦Vd3≦30, 16≦Vd3≦30 and 17.3≦Vd3≦30.
As shown in
In one embodiment, the fourth lens L4 has an Abbe number Vd4, and Vd4 may satisfy at least one of the following conditions: 60≦Vd4, 62≦Vd4, 64.5≦Vd4, Vd4≦78.6, Vd4≦81, Vd4≦85, 60≦Vd4≦78.6, 62≦Vd4≦78.6, 64.5≦Vd4≦78.6, 60≦Vd4≦81, 62≦Vd4≦81, 64.5≦Vd4≦81, 60≦Vd4≦85, 62≦Vd4≦85 and 64.5≦Vd4≦85.
As shown in
The optical lens OL1 may further include a focal length F and a length TTL. In one embodiment, the optical lens OL1 may satisfy at least one of the following conditions: 0≦F/TTL, 0.05≦F/TTL, 0.1≦F/TTL, F/TTL≦0.15, F/TTL≦0.2, F/TTL≦0.25, 0≦F/TTL≦0.25, 0≦F/TTL≦0.2, 0≦F/TTL≦0.15, 0.05≦F/TTL≦0.25, 0.05≦F/TTL≦0.2, 0.05≦F/TTL≦0.15, 0.1≦F/TTL≦0.25, 0.1≦F/TTL≦0.2 and 0.1≦F/TTL≦0.15. The length TTL may be a distance between an object-side surface of the lens, which closest to the object side within the optical lens OL1, and the imaging plane I. For example, the length TTL may be a distance from an object-side surface of the first lens group G1 to the imaging plane I that may be along an optical axis OX of the optical lens OL1. Also, the length TTL may be a distance between an object-side surface S1 of the first lens L1 and the imaging plane I.
The optical lens OL1 may further include an image height Y. In one embodiment, the optical lens OL1 may satisfy at least one of the following conditions: 0≦F/Y, 0.3≦F/Y. 0.5≦F/Y, 0.6≦F/Y, 0.66≦F/Y, F/Y≦0.71, F/Y≦0.75, F/Y≦0.8, F/Y≦0.85, F/Y≦1, 0≦F/Y≦0.71, 0≦F/Y≦0.75, 0≦F/Y≦0.8, 0≦F/Y≦0.85, 0≦F/Y≦1, 0.3≦F/Y≦0.71, 0.3≦F/Y≦0.75, 0.3≦F/Y≦0.8, 0.35≦F/Y≦0.85, 0.3≦F/Y≦1, 0.55≦F/Y≦0.71, 0.5≦F/Y≦0.75, 0.5≦F/Y≦0.8, 0.5≦F/Y≦0.85, 0.5≦F/Y≦1, 0.6≦F/Y≦0.71, 0.6≦F/Y≦0.75, 0.6≦F/Y≦0.8, 0.6≦F/Y≦0.85, 0.6≦F/Y≦1, 0.66≦F/Y≦0.71, 0.66≦F/Y≦0.75, 0.66≦F/Y≦0.8, 0.66≦F/Y≦0.85 and 0.66≦F/Y≦1.
In one embodiment, the optical lens OL1 may satisfy at least one of the following conditions: 0≦d/F, 0.1≦d/F, 0.18≦d/F, d/F≦0.31, d/F=0.4, d/F≦0.45, 0≦d/F≦0.31, 0≦d/F≦0.4, 0≦d/F≦0.45, 0.1≦d/F≦0.31, 0.1≦d/F≦0.4, 0.1≦d/F≦0.45, 0.18≦d/F≦0.31, 0.18≦d/F≦0.4 and 0.18≦d/F≦0.45, wherein d may be a distance between the third lens L3 and the cemented lens C1, or may be a distance between the first lens group G1 and the second lens group G2. That is d may be a distance between an image-side surface of the first lens group G1 and an object-side surface of the second lens group G2.
On the other hand, d may also be a distance between an image-side surface S6 of the third lens L3 and an object-side surface S9 of the fifth lens L5.
The optical lens OL1 may further have a field of view FOV. In one embodiment, the optical lens OL1 may satisfy at least one of the following conditions: 140°≦FOV, 165°≦FOV, FOV≦185°, 140°≦FOV≦185° and 165°≦FOV≦185°.
The optical lens OL1 may further include an aperture FNO. In one embodiment, the optical lens OL1 may satisfy at least one of the following conditions: 0≦(FNO×TTL)/(FOV×Y), 0.05≦(FNO×TTL)/(FOV×Y), 0.1≦(FNO×TTL)/(FOV×Y), (FNO×TTL)/(FOV×Y)≦0.15, (FNO×TTL)/(FOV×Y)≦0.2, 0≦(FNO×TTL)/(FOV×Y)≦0.15, 0.05≦(FNO×TTL)/(FOV×Y)≦0.15, 0.1≦(FNO×TTL)/(FOV×Y)≦0.15, 0≦(FNO×TTL)/(FOV×Y)≦0.2, 0.05≦(FNO×TTL)/(FOV×Y)≦0.2 and 0.1≦(FNO×TTL)/(FOV×Y)≦0.2.
Furthermore, in one embodiment, the fourth lens L4 may have an effective diameter D including but not limited to an optical effective diameter or a physical diameter. The optical lens OL1 may satisfy at least one of the following conditions: 1.33≦D/Y, 1.5≦D/Y, 1.72≦D/Y, D/Y≦2.12, D/Y≦2.3, D/Y≦2.47, 1.33≦D/Y≦2.12, 1.33≦D/Y≦2.3, 1.33≦D/Y≦2.47, 1.5≦D/Y≦2.12, 1.5≦D/Y≦2.3, 1.5≦D/Y≦2.47, 1.72≦D/Y≦2.12, 1.72≦D/Y≦2.3 and 1.72≦D/Y≦2.47.
In
Besides, in one embodiment, the first lens L1 the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 may respectively be a glass lens made of a glass material or a plastic lens made of a plastic material. And, the plastic material may include, but not limited to, polycarbonate, cyclic olefin copolymer (e.g. APEL), polyester resins (e.g. OKP4 or OKP4HT), and the like, or a mixture material and/or a compound material including at least one of the above-mentioned three materials.
In one embodiment, the first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5, the sixth lens L6 and the seventh lens L7 may respectively be a spheric lens, a free-form lens or an aspheric lens. For example, the first lens L1, the second lens L2, the third lens L3, the fifth lens L5, the sixth lens L6 and the seventh lens L7 may all be spheric lenses, and the fourth lens L4 may be an aspheric lens including but not limited to an aspheric glass lens or an aspheric plastic lens.
Specifically, each of the free-form lenses has at least one free-form surface; that is, an object-side surface and/or an image-side surface of the free-form lens are/is the free-form surface(s). Each of the aspheric lenses has at least one aspheric surface; that is, an object-side surface and/or an image-side surface of the aspheric lens are/is the aspheric surface(s). Each of the aspheric surfaces satisfies the following equation:
where Z is the coordinate in the optical axis direction, and the direction in which light propagates is designated as positive; A4, A6, A8, A10, A12, A14, and A16 are aspheric coefficients; K is coefficient of quadratic surface; C is reciprocal of R (C=1/R); R is the radius of curvature; Y is the coordinate in a direction perpendicular to the optical axis, in which the upward direction away from the optical axis is designated as positive. In addition, each of the parameters or the coefficients of the equation of each of the aspheric surfaces may be independent of one another.
As shown in
The object-side surface S1 of the first lens L1 and the object-side surface S3 of the second lens L2 may both have positive refractive rates and may respectively be a convex surface toward the object side. The image-side surface S2, S4 of the first lens L1 and the second lens L2 may both have positive refractive rates and may respectively be a concave surface toward the object side. Furthermore, the first lens L1 and the second lens L2 may be a lens having negative refractive power respectively, such as a convex-concave lens having negative refractive power including but not limited to a convex-concave plastic lens or a convex-concave glass lens. In addition, the object-side surfaces S1, S3 and the image-side surfaces S2, S4 may be a spheric surface, a free-form surface and/or an aspheric surface respectively.
The object-side surface S5 of the third lens L3 and the object-side surface S7 of the fourth lens L4 may both have positive refractive rates and may be a convex surface toward the object side respectively. The image-side surface S6, S8 of the third lens L3 and the fourth lens L4 may both have negative refractive rates and may be a convex surface toward the image-forming side respectively. Furthermore, the third lens L3 and the fourth lens L4 may respectively be a lens having positive refractive power, such as a biconvex lens having positive refractive power including but not limited to a biconvex plastic lens or a biconvex glass lens having positive refractive power. In addition, the object-side surfaces S5, S7 and the image-side surfaces S6, S8 may be a spheric surface, a free-form surface and/or an aspheric surface respectively.
The object-side surface S9 of the cemented lens C1, the object-side surface S9 of the fifth lens L5, may have negative refractive rate and may be a concave surface toward the image-forming side. The bonding surface S10 between the fifth lens L5 and the sixth lens L6 may have negative refractive rate and may curve toward the image-forming side at the optical axis OX. The shapes of the image-side surface of the fifth lens L5 (not designated) and the object-side surface of the sixth lens L6 (not designated) may substantially or approximately the same to the bonding surface S10. The bonding surface S11 between the sixth lens L6 and the seventh lens L7 may have positive refractive rate and may toward the object side at the optical axis OX. The shapes of the image-side surface of the sixth lens L6 (not designated) and the object-side surface of the seventh lens L7 (not designated) may substantially or approximately the same to the bonding surface S11. The image-side surface S12 of the cemented lens C1, the image-side surface S12 of the seventh lens L7, may have negative refractive rate and may be a convex surface toward the image-forming side.
Furthermore, the fifth lens L5 may be a lens having positive refractive power, such as a concave-convex lens having positive refractive power including but not limited to a concave-convex plastic lens or a concave-convex glass lens having positive refractive power. The sixth lens L6 may be a lens having negative refractive power, such as a biconcave lens having negative refractive power including but not limited to a biconcave plastic lens or a biconcave glass lens having negative refractive power. The seventh lens L7 may be a lens having positive refractive power, such as a biconvex lens having positive refractive power including but not limited to a biconvex plastic lens or a biconvex glass lens having positive refractive power. In addition, the object-side surface S9 and the image-side surface S12 of the cemented lens C1 and the surfaces S10, S11 may be a spheric surface, a free-form surface and/or an aspheric surface respectively.
Furthermore, referring to
On the other hand, the optical lens OL1 may further include a filter Ft. The filter Ft may be arranged between the seventh lens L7 and the cover Co. In another embodiment, the cover Co may combine the functions in protecting the image capturing unit and filtering the infrared light beams, and the filter Ft may be omitted.
As shown in
In one embodiment, the first lens group G1 has negative refractive power and includes the first lens L1, the second lens L2, the eighth lens L8 and the third lens L3. The second lens group G2 has positive refractive power and includes the sixth lens L6, the seventh lens L7 and the fourth lens L4.
In one embodiment, the eighth lens L8 may be a glass lens made of a glass material or a plastic lens made of a plastic material.
In one embodiment, the eighth lens L8 may be a spheric lens, a free-form lens or an aspheric lens. Specifically, the eighth lens L8 may be a glass spheric lens, a plastic spheric lens, a glass free-form lens, a plastic free-form lens, a glass aspheric lens or a plastic aspheric lens.
In one embodiment, the eighth lens L8 may have refractive power. In another embodiment, the eighth lens L8 may have negative refractive power.
In one embodiment, the object-side surface S15 of the eighth lens L8 may have positive refractive rate and may be a convex surface toward the object side. The image-side surface S16 of the eighth lens L8 may have positive refractive rate and may be a concave surface toward the object side. Furthermore, the eighth lens L8 may be a lens having negative refractive power, such as a convex-concave lens having negative refractive power including but not limited to a convex-concave plastic lens or a convex-concave glass lens. In addition, the object-side surface S15 and the image-side surface S16 may be a spheric surface, a free-form surface and/or an aspheric surface respectively.
Furthermore,
While the invention has been described by way of example and in terms of the preferred embodiment(s), it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.
Number | Date | Country | Kind |
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105109875 | Mar 2016 | TW | national |