Patent Grant
11402614
The present disclosure relates to the field of optical lens, and more particularly, to a camera optical lens suitable for handheld terminal devices, such as smart phones or digital cameras, and imaging devices, such as monitors or PC lenses.
With the emergence of smart phones in recent years, the demand for miniature camera lens is increasing day by day, but in general the photosensitive devices of camera lens are nothing more than Charge Coupled Device (CCD) or Complementary Metal-Oxide Semiconductor Sensor (CMOS sensor), and as the progress of the semiconductor manufacturing technology makes the pixel size of the photosensitive devices become smaller, plus the current development trend of electronic products towards better functions and thinner and smaller dimensions, miniature camera lenses with good imaging quality therefore have become a mainstream in the market. In order to obtain better imaging quality, the lens that is traditionally equipped in mobile phone cameras adopts a three-piece or four-piece lens structure. Also, with the development of technology and the increase of the diverse demands of users, and as the pixel area of photosensitive devices is becoming smaller and smaller and the requirement of the system on the imaging quality is improving constantly, the five-piece, six-piece and seven-piece lens structures gradually appear in lens designs. There is an urgent need for ultra-thin, wide-angle camera lenses with good optical characteristics and fully corrected chromatic aberration.
Many aspects of the exemplary embodiment can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
The present disclosure will hereinafter be described in detail with reference to several exemplary embodiments. To make the technical problems to be solved, technical solutions and beneficial effects of the present disclosure more apparent, the present disclosure is described in further detail together with the figure and the embodiments. It should be understood the specific embodiments described hereby is only to explain the disclosure, not intended to limit the disclosure.
Referring to
The first lens L1, the second lens L2, the third lens L3, the fourth lens L4, the fifth lens L5 and the sixth lens L6 are all made of a plastic material.
The second lens L2 has a negative refractive power, and the third lens L3 has a negative refractive power.
Here, a focal length of the first lens L1 is defined as f1, and a focal length of the second lens L2 is defined as f2. The camera optical lens 10 should satisfy a condition of −3.00≤f1/f2≤−1.00, which specifies a ratio of the focal length f1 of the first lens L1 and the focal length f2 of the second lens L2. The appropriate distribution of the refractive power leads to a better imaging quality and a lower sensitivity. Preferably, −2.01≤f1/f2≤−1.00.
A curvature radius of an object side surface of the second lens L2 is defined as R3, and a curvature radius of an image side surface of the second lens L2 is defined as R4. The camera optical lens 10 further satisfies a condition of −30.00≤R3/R4≤−2.00. The refractive index within this range facilitates development of ultra-thin lenses, and also facilitates correction of an aberration. Preferably, −28.05≤R3/R4≤−2.03.
A total optical length from an object side surface of the first lens L1 to an image plane of the camera optical lens 10 along an optic axis is defined as TTL. When the focal length of the first lens, the focal length of the second lens, the curvature radius of the object side surface of the second lens and the curvature radius of the image side surface of the second lens satisfy the above conditions, the camera optical lens will have the advantage of high performance and satisfy the design requirement of a low TTL.
In this embodiment, the object side surface of the first lens L1 is convex in a paraxial region, the image side surface of the first lens L1 is convex in the paraxial region, and the first lens L1 has a positive refractive power.
A focal length of the camera optical lens 10 is defined as f, and the focal length of the first lens L1 is defined as f1. The camera optical lens 10 should satisfy a condition of 0.34≤f1/f≤1.25, which specifies a ratio of the focal length f1 of the first lens L1 and the focal length f of the camera optical lens 10 If the lower limit of the specified value is exceeded, although it would facilitate development of ultra-thin lenses, the positive refractive power of the first lens L1 will be too strong, and thus it is difficult to correct the problem like the aberration and it is also unfavorable for development of wide-angle lenses. On the contrary, if the upper limit of the specified value is exceeded, the positive refractive power of the first lens L1 would become too weak, and it is then difficult to develop ultra-thin lenses. Preferably, 0.54≤f1/f≤1.00.
A curvature radius of the object side surface of the first lens L1 is defined as R1 and a curvature radius of the image side surface of the first lens L1 is defined as R2. The camera optical lens 10 further satisfies a condition of −2.00≤(R1+R2)/(R1−R2)≤−0.63. This can reasonably control a shape of the first lens L1 in such a manner that the first lens L1 can effectively correct a spherical aberration of the camera optical lens. Preferably, −1.25≤(R1+R2)/(R1−R2)≤−0.79.
An on-axis thickness of the first lens L1 is defined as d1. The camera optical lens 10 further satisfies a condition of 0.07≤d1/TTL≤0.24. This facilitates achieving ultra-thin lenses. Preferably, 0.12≤d1/TTL≤0.19.
In this embodiment, an object side surface of the second lens L2 is concave in the paraxial region, and an image side surface of the second lens L2 is concave in the paraxial region.
The focal length of the camera optical lens 10 is defined as f, and a focal length of the second lens L2 is f2. The camera optical lens 10 further satisfies a condition of −1.65≤f2/f≤−0.44. By controlling the negative refractive power of the second lens L2 within the reasonable range, correction of the aberration can be facilitated. Preferably, −1.03≤f2/f≤−0.55.
A curvature radius of the object side surface of the second lens L2 is defined as R3, and a curvature radius of the image side surface of the second lens L2 is defined as R4. The camera optical lens 10 further satisfies a condition of 0.17≤(R3+R4)/(R3−R4)≤1.39. This can reasonably control a shape of the second lens L2. Out of this range, a development towards ultra-thin and wide-angle lenses would make it difficult to correct the problem of the aberration. Preferably, 0.28≤(R3+R4)/(R3−R4)≤1.11.
An on-axis thickness of the second lens L2 is defined as d3. The camera optical lens 10 further satisfies a condition of 0.02≤d3/TTL≤0.08. This facilitates achieving ultra-thin lenses. Preferably, 0.04≤d3/TTL≤0.06.
In this embodiment, the focal length of the camera optical lens 10 is defined as f, and a focal length of the third lens L3 is f3. The camera optical lens 10 further satisfies a condition of −5268.98≤f3/f≤−1072.02. When the condition is satisfied, the field curvature of the system can be well balanced for further improving the image quality. Preferably, −3293.11≤f3/f≤−1340.02.
A curvature radius of the object side surface of the third lens L3 is defined as R5, and a curvature radius of the image side surface of the third lens L3 is defined as R6. The camera optical lens 10 further satisfies a condition of −3.98≤(R5+R6)/(R5−R6)≤184.06. This can effectively control a shape of the third lens L3, thereby facilitating shaping of the third lens L3 and avoiding bad shaping and generation of stress due to the overly large surface curvature of the third lens L3. Preferably, −2.49≤(R5+R6)/(R5−R6)≤147.25.
An on-axis thickness of the third lens L3 is defined as d5. The camera optical lens 10 further satisfies a condition of 0.02≤d5/TTL≤0.07. This facilitates achieving ultra-thin lenses. Preferably, 0.03≤d5/TTL≤0.06.
In this embodiment, an object side surface of the fourth lens L4 is convex in the paraxial region, an image side surface of the fourth lens L4 is convex in the paraxial region, and the fourth lens L4 has a positive refractive power.
The focal length of the camera optical lens 10 is defined as f, and a focal length of the fourth lens L4 is f4. The camera optical lens 10 further satisfies a condition of 0.57≤f4/f≤2.15. The appropriate distribution of the refractive power leads to a better imaging quality and a lower sensitivity. Preferably, 0.91≤f4/f≤1.72.
A curvature radius of the object side surface of the fourth lens L4 is defined as R7, and a curvature radius of the image side surface of the fourth lens L4 is defined as R8. The camera optical lens 10 further satisfies a condition of −2.00≤(R7+R8)/(R7−R8)≤−0.67, which specifies a shape of the fourth lens L4. Out of this range, a development towards ultra-thin and wide-angle lenses would make it difficult to correct the problem like an off-axis aberration. Preferably, −1.25≤(R7+R8)/(R7−R8)≤−0.83.
An on-axis thickness of the fourth lens L4 is defined as d7. The camera optical lens 10 further satisfies a condition of 0.02≤d7/TTL≤0.07. This facilitates achieving ultra-thin lenses. Preferably, 0.03≤d7/TTL≤0.05.
In this embodiment, an object side surface of the fifth lens L5 is convex in the paraxial region, an image side surface of the fifth lens L5 is convex in the paraxial region, and the fifth lens L5 has a positive refractive power.
The focal length of the camera optical lens 10 is defined as f, and a focal length of the fifth lens L5 is f5. The camera optical lens 10 further satisfies a condition of 0.60≤f5/f≤1.83. This can effectively make a light angle of the camera lens gentle and reduce the tolerance sensitivity. Preferably, 0.96≤f5/f≤1.46.
A curvature radius of the object side surface of the fifth lens L5 is defined as R9, and a curvature radius of the image side surface of the fifth lens L5 is defined as R10. The camera optical lens 10 further satisfies a condition of −0.98≤(R9+R10)/(R9−R10)<−0.31, which specifies a shape of the fifth lens L5. Out of this range, a development towards ultra-thin and wide-angle lenses would make it difficult to correct the problem like an off-axis aberration. Preferably, −0.61≤(R9+R10)/(R9−R10)≤−0.38.
An on-axis thickness of the fifth lens L5 is defined as d9. The camera optical lens 10 further satisfies a condition of 0.04≤d9/TTL≤0.14. This facilitates achieving ultra-thin lenses. Preferably, 0.07≤d9/TTL≤0.11.
In this embodiment, an object side surface of the sixth lens L6 is concave in the paraxial region, an image side surface of the sixth lens L6 is concave in the paraxial region, and the sixth lens L6 has a negative refractive power.
The focal length of the camera optical lens 10 is defined as f, and a focal length of the sixth lens L6 is f6. The camera optical lens 10 further satisfies a condition of −1.31≤f6/f≤−0.38. The appropriate distribution of the refractive power leads to a better imaging quality and a lower sensitivity. Preferably, −0.82≤f6/f≤−0.48.
A curvature radius of the object side surface of the sixth lens L6 is defined as R11, and a curvature radius of the image side surface of the sixth lens L6 is defined as R12. The camera optical lens 10 further satisfies a condition of 0.17≤(R11+R12)/(R11−R12)≤0.59, which specifies a shape of the sixth lens L6. Out of this range, a development towards ultra-thin and wide-angle lenses would make it difficult to correct the problem like an off-axis aberration. Preferably, 0.28≤(R11+R12)/(R11−R12)≤0.47.
An on-axis thickness of the sixth lens L6 is defined as d11. The camera optical lens 10 further satisfies a condition of 0.04≤d11/TTL≤0.13. This facilitates achieving ultra-thin lenses. Preferably, 0.07≤d11/TTL≤0.11.
In this embodiment, the focal length of the camera optical lens 10 is defined as f, and a combined focal length of the first lens L1 and the second lens L2 is f12. The camera optical lens 10 further satisfies a condition of 1.48≤f12/f≤6.82. This can eliminate the aberration and distortion of the camera optical lens while suppressing a back focal length of the camera optical lens, thereby maintaining miniaturization of the camera lens system. Preferably, 2.37≤f12/f≤5.45.
In this embodiment, the total optical length TTL of the camera optical lens 10 is smaller than or equal to 4.38 mm, which is beneficial for achieving ultra-thin lenses. Preferably, the total optical length TTL of the camera optical lens 10 is smaller than or equal to 4.18 mm.
In this embodiment, the camera optical lens 10 has a large F number, which is smaller than or equal to 2.27. The camera optical lens 10 has a better imaging performance. Preferably, the F number of the camera optical lens 10 is smaller than or equal to 2.22.
With such design, the total optical length TTL of the camera optical lens 10 can be made as short as possible, and thus the miniaturization characteristics can be maintained.
In the following, examples will be used to describe the camera optical lens 10 of the present disclosure. The symbols recorded in each example will be described as follows. The focal length, on-axis distance, curvature radius, on-axis thickness, inflexion point position, and arrest point position are all in units of mm.
TTL: Optical length (the total optical length from the object side surface of the first lens to the image plane of the camera optical lens along the optic axis) in mm.
Preferably, inflexion points and/or arrest points can be arranged on the object side surface and/or image side surface of the lens, so as to satisfy the demand for the high quality imaging. The description below can be referred to for specific implementations.
The design information of the camera optical lens 10 in Embodiment 1 of the present disclosure is shown in Tables 1 and 2.
Table 2 shows aspherical surface data of the camera optical lens 10 in Embodiment 1 of the present disclosure.
Here, K is a conic coefficient, and A4, A6, A8, A10, Al2, A14, A16, A18 and A20 are aspheric surface coefficients.
IH: Image Height
y=(x2/R)/[1+{1−(k+1)(x2/R2)}1/2]+A4x4+A6x6+A8x8+A10x10+A12x12+A14x14+A16x16+A18x18+A20x20 (1)
For convenience, an aspheric surface of each lens surface uses the aspheric surfaces shown in the above formula (1). However, the present disclosure is not limited to the aspherical polynomials form shown in the formula (1).
Table 3 and Table 4 show design data of inflexion points and arrest points of respective lens in the camera optical lens 10 according to Embodiment 1 of the present disclosure. P1R1 and P1R2 represent the object side surface and the image side surface of the first lens L1, P2R1 and P2R2 represent the object side surface and the image side surface of the second lens L2, P3R1 and P3R2 represent the object side surface and the image side surface of the third lens L3, P4R1 and P4R2 represent the object side surface and the image side surface of the fourth lens L4, P5R1 and P5R2 represent the object side surface and the image side surface of the fifth lens L5, and P6R1 and P6R2 represent the object side surface and the image side surface of the sixth lens L6. The data in the column named “inflexion point position” refers to vertical distances from inflexion points arranged on each lens surface to the optic axis of the camera optical lens 10 The data in the column named “arrest point position” refers to vertical distances from arrest points arranged on each lens surface to the optic axis of the camera optical lens 10.
Table 9 shows various values of Embodiments 1 and 2 and values corresponding to parameters which are specified in the above conditions.
As shown in Table 9, Embodiment 1 satisfies the above conditions.
In this embodiment, the entrance pupil diameter of the camera optical lens is 1.415 mm. The image height of 1.0 H is 2.62 mm. The FOV (field of view) is 76.04°. Thus, the camera optical lens has a wide-angle and is ultra-thin. Its on-axis and off-axis chromatic aberrations are fully corrected, thereby achieving excellent optical characteristics.
Embodiment 2 is basically the same as Embodiment 1 and involves symbols having the same meanings as Embodiment 1, and only differences therebetween will be described in the following.
Table 5 and Table 6 show design data of a camera optical lens 20 in Embodiment 2 of the present disclosure.
Table 6 shows aspherical surface data of each lens of the camera optical lens 20 in Embodiment 2 of the present disclosure.
Table 7 and Table 8 show design data of inflexion points and arrest points of respective lens in the camera optical lens 20 according to Embodiment 2 of the present disclosure.
As shown in Table 9, Embodiment 2 satisfies the above conditions.
In this embodiment, the entrance pupil diameter of the camera optical lens is 1.503 mm. The image height of 1.0 H is 2.62 mm. The FOV (field of view) is 74.64°. Thus, the camera optical lens has a wide-angle and is ultra-thin. Its on-axis and off-axis chromatic aberrations are fully corrected, thereby achieving excellent optical characteristics.
Table 9 in the following lists values corresponding to the respective conditions in this embodiment in order to satisfy the above conditions.
It can be appreciated by one having ordinary skill in the art that the description above is only embodiments of the present disclosure. In practice, one having ordinary skill in the art can make various modifications to these embodiments in forms and details without departing from the spirit and scope of the present disclosure.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201811650474.5 | Dec 2018 | CN | national |
| Number | Name | Date | Kind |
|---|---|---|---|
| 5699202 | Yamamoto | Dec 1997 | A |
| Number | Date | Country | |
|---|---|---|---|
| 20200209587 A1 | Jul 2020 | US |
