CN112630942B

CN112630942B - Optical imaging lens

Info

Publication number: CN112630942B
Application number: CN202110188240.9A
Authority: CN
Inventors: 张星明; 华成强; 焦暘; 韩冬; 王皓; 张泽鹏
Original assignee: Genyu Muxing Beijing Space Technology Co ltd
Current assignee: Genyu Muxing Beijing Space Technology Co ltd
Priority date: 2021-02-19
Filing date: 2021-02-19
Publication date: 2021-11-12
Anticipated expiration: 2041-02-19
Also published as: CN112630942A

Abstract

The embodiment of the invention relates to the field of optical imaging lenses and discloses an optical imaging lens. In the present invention, an optical imaging lens is provided, which includes, in order from an object side to an image side, a first lens L1 having positive optical power, a second lens L2 having negative optical power, a third lens L3 having negative optical power, a fourth lens L4 having positive optical power, a fifth lens L5 having positive optical power, a sixth lens L6 having negative optical power, a seventh lens L7 having positive optical power, and an eighth lens L8 having negative optical power. An infrared filter IR and an image plane of an image sensor S are arranged at the image side of the optical imaging lens. The infrared filter IR is disposed between the eighth lens L8 and the imaging surface, and the infrared filter IR filters the light passing through the optical imaging lens to a specific wavelength band, for example, to a near infrared wavelength band, so that the wavelength of the near infrared wavelength band is not imaged on the imaging surface.

Description

Optical imaging lens

Technical Field

The embodiment of the invention relates to the technical field of optical imaging, in particular to an optical imaging lens.

Background

With the increasing and decreasing specifications of electronic products, optical imaging lenses mounted thereon are also becoming more diversified, and not only light and thin and have good imaging quality, but also designs with larger aperture and field angle are pursued. The existing optical imaging lens is thick and heavy, and the design of aperture value and field angle can not satisfy the market demand.

The traditional lens mainly adopts a three-piece or four-piece lens structure. With the development of technology and the increasing of diversified demands of users, under the conditions that the pixel area of a photosensitive device is continuously reduced and the requirement of a system on the imaging quality is continuously improved, an eight-piece lens structure gradually appears in the design of a lens. However, it is a goal in the industry to obtain a better imaging quality and reduce the length of the optical imaging lens, and to obtain an eight-lens with an excellent field angle and aperture size.

Disclosure of Invention

In view of the above problems, an object of the present invention is to provide an optical imaging lens that can satisfy the requirements of excellent field angle and light weight while achieving high imaging performance.

In order to solve the above technical problem, the present application provides an optical imaging lens including, in order from an object side to an image side, a first lens L1 having positive optical power, a second lens L2 having negative optical power, a third lens L3 having negative optical power, a fourth lens L4 having positive optical power, a fifth lens L5 having positive optical power, a sixth lens L6 having negative optical power, a seventh lens L7 having positive optical power, and an eighth lens L8 having negative optical power. An infrared filter IR and an image plane of an image sensor S are arranged at the image side of the optical imaging lens. The infrared filter IR is disposed between the eighth lens L8 and the imaging surface, and the infrared filter IR filters the light passing through the optical imaging lens to a specific wavelength band, for example, to a near infrared wavelength band, so that the wavelength of the near infrared wavelength band is not imaged on the imaging surface.

The total focal length of the optical imaging lens is f, the value range of f is more than or equal to 2mm and less than or equal to 5mm, the preferred value range of f is more than or equal to 3mm and less than or equal to 4.5mm, and the more selected value range of f is more than or equal to 3.5mm and less than or equal to 4.2 mm.

The total optical length of the optical imaging lens is TTL, the value range of TTL is not less than 4.8mm and not more than 5.5mm, the preferable value range is not less than 4.9mm and not more than 5.4mm, and the more preferable value range is not less than 5mm and not more than 5.3 mm.

The half field angle of the optical imaging lens is HFOV, the value range of the HFOV is more than 40 degrees, the preferred value range is not less than 40 degrees and not more than 50 degrees, and the more preferred value range is not less than 40 degrees and not more than 42 degrees.

The F NUMBER of the optical imaging lens meets the condition that F-NUMBER is less than 1.8.

The focal length of the first lens L1 is f1, the range of f1 is 3 mm-f 1-4 mm, the preferable range is 3.5 mm-f 1-3.8 mm, and the more preferable range is 3.591 mm-f 1-3.775 mm. The ratio of the focal length of the first lens L1 to the total focal length of the system satisfies f1/f is less than or equal to 0.8 and less than or equal to 1.2, and the spherical aberration and the field curvature of the system can be effectively balanced within the range. Further, the preferable value range is 0.85. ltoreq. f 1/f. ltoreq.1.15, and the more preferable value range is 0.9. ltoreq. f 1/f. ltoreq.1.1.

The first lens element L1 has positive power and has an object-side surface L11 and an image-side surface L12. The curvature radius of the object side surface L11 of the first lens L1 is R11, the curvature radius of the image side surface L12 of the first lens L1 is R12, and the curvature radius of the object side surface and the curvature radius of the image side surface of the first lens L1 are equal to or larger than-1.2 and equal to or larger than (R11+ R12)/(R11-R12) and equal to or larger than-0.8. Further, the preferable range is-1.1. ltoreq. (R11+ R12)/(R11-R12. ltoreq. -0.9, more preferably-1.05. ltoreq. (R11+ R12)/(R11-R12). ltoreq. -0.92.

On the other hand, the optical axis region of the object-side surface L11 of the first lens element L1 is convex, and the optical axis region of the image-side surface L22 is concave. The object-side surface and the image-side surface of the first lens element L1 are aspheric. The curvature radius of the object side surface and the image side surface of the first lens L1 satisfies 0.01 ≦ R11/R12 ≦ 0.03, and more preferably 0.015 ≦ R11/R12 ≦ 0.025.

On the other hand, the optical axis region of the object-side surface L11 of the first lens element L1 is convex, and the optical axis region of the image-side surface L22 is convex. The object-side surface and the image-side surface of the first lens element L1 are aspheric. The curvature radius of the object side surface and the image side surface of the first lens L1 is more than or equal to-0.05 and less than or equal to R11/R12 and less than or equal to 0, preferably more than or equal to-0.04 and less than or equal to R11/R12 and less than or equal to-0.01, and further more preferably more than or equal to-0.035 and less than or equal to R11/R12 and less than or equal to-0.02.

The on-axis thickness of the first lens L1 is d11, the on-axis distance from the image side face L12 of the first lens L1 to the object side face L21 of the second lens L2 is d12, and the requirements of 15 ≦ d11/d12 ≦ 20, 16 ≦ d11/d12 ≦ 19 are preferred, and 17 ≦ d11/d12 ≦ 18 are more preferred. 0.05 is less than or equal to d11/TTL is less than or equal to 0.2, preferably 0.07 is less than or equal to d11/TTL is less than or equal to 0.18, further preferably 0.08 is less than or equal to d11/TTL is less than or equal to 0.15, and the above range is satisfied, thereby being beneficial to realizing ultra-thinning.

The focal length of the second lens L2 is f2, f2 is in the range of-6 mm to f 2mm, preferably-5.8 mm to f 2mm, more preferably-5.651 mm to f 2mm to 5.397mm, which is helpful for correcting system aberration. The ratio of the focal length of the second lens L2 to the total focal length of the system satisfies-2 and f2/f and-1, and the spherical aberration and the field curvature of the system can be effectively balanced within the range. Further, the preferable value range is-1.8 ≤ f2/f ≤ -1.2, and the more preferable value range is-1.52 ≤ f2/f ≤ 1.402.

The second lens element L2 has negative power and has an object-side surface L21 and an image-side surface L22. On the other hand, the optical axis region of the object-side surface L21 of the second lens element L2 is convex, and the optical axis region of the image-side surface L22 is concave. The object-side surface and the image-side surface of the second lens element L2 are aspheric. The curvature radius of the object side surface of the second lens L2 is R21, the curvature radius of the image side surface of the second lens L2 is R22, and the requirement of 2 ≦ (R21+ R22)/(R21-R22) ≦ 3 is preferably 2.5 ≦ (R21+ R22)/(R21-R22) ≦ 2.8. R21/R22 satisfies 1.5. ltoreq.R 21/R22. ltoreq.3, and more preferably 2. ltoreq.R 21/R22. ltoreq.2.5.

On the other hand, the optical axis region of the object-side surface L21 of the second lens L2 is concave, and the optical axis region of the image-side surface L22 is concave. The object-side surface and the image-side surface of the second lens element L2 are aspheric. The curvature radius of the object side surface of the second lens L2 is R21, the curvature radius of the image side surface of the second lens L2 is R22, and the curvature radius satisfies 0 ≦ (R21+ R22)/(R21-R22) ≦ 2, preferably 0.5 ≦ (R21+ R22)/(R21-R22) ≦ 1.5. R21/R22 satisfies-45. ltoreq.R 21/R22. ltoreq. -35, more preferably-40. ltoreq.R 21/R22. ltoreq. -37.

The on-axis thickness of the second lens L2 is d21, the on-axis distance from the image side surface of the second lens L2 to the object side surface of the third lens L3 is d22, and the requirements that d21/d22 is more than or equal to 1 and less than or equal to 5, preferably that d21/d22 is more than or equal to 1.5 and less than or equal to 3, and more preferably that d21/d22 is more than or equal to 2.5 are met. 0.02. ltoreq. d 21/TTL. ltoreq.0.1, preferably 0.05. ltoreq. d 21/TTL. ltoreq.0.09.

The focal length of the third lens L3 is f3, the value range of f3 is-150 mm-f 3-120 mm, the preferable value range is-145 mm-f 3-131 mm, and the more preferable value range is-140 mm-f 3-130 mm. The ratio of the focal length of the third lens L3 to the total focal length of the system meets the condition that f3/f is less than or equal to-40 and less than or equal to-20, and in the range, the imaging quality can be improved. Further, the preferable value range is-40 ≤ f3/f ≤ -30, and the more preferable value range is-39 ≤ f3/f ≤ 32.

The third lens element L3 has negative power and has an object-side surface L31 and an image-side surface L32. The optical axis region of the object-side surface L31 is convex, and the optical axis region of the image-side surface L32 is concave. The object-side surface and the image-side surface of the third lens element L3 are aspheric. The radius of curvature of the object-side surface of the third lens L3 is R31, and the radius of curvature of the image-side surface of the third lens L3 is R32, and satisfies 5 ≦ (R31+ R32)/(R31-R32) ≦ 20, preferably 8 ≦ (R31+ R32)/(R31-R32) ≦ 12, within which the degree of light ray deflection is facilitated to be reduced and the aberration is reduced. Furthermore, 1. ltoreq. R31/R32. ltoreq.2, preferably 1. ltoreq. R31/R32. ltoreq.1.5.

The on-axis thickness of the third lens L3 is d31, the on-axis distance from the image side surface of the third lens L3 to the object side surface of the fourth lens L4 is d32, and d31/d32 satisfies 1. ltoreq. d31/d 32. ltoreq.5, preferably 1. ltoreq. d31/d 32. ltoreq.3, and more preferably 1. ltoreq. d31/d 32. ltoreq.1.5. D31/TTL is more than or equal to 0.02 and less than or equal to 0.1, and d21/TTL is more than or equal to 0.03 and less than or equal to 0.05, so that ultra-thinning is realized.

The focal length of the fourth lens L4 is f4, the range of f4 is 10mm ≤ f4 ≤ 18mm, preferably 14mm ≤ f4 ≤ 18mm, and more preferably 15mm ≤ f4 ≤ 17.7 mm. The ratio of the focal length of the fourth lens L4 to the total focal length of the system satisfies f4/f 5 or more, and the spherical aberration and the field curvature of the system can be effectively balanced within the range. Further, the preferable value range is 3.5. ltoreq. f 4/f. ltoreq.5, and the more preferable value range is 3.8. ltoreq. f 4/f. ltoreq.5.

The fourth lens element L4 has positive power and has an object-side surface L41 and an image-side surface L42. On the other hand, the optical axis region of the object-side surface L41 is concave, and the optical axis region of the image-side surface L42 is convex. The object-side surface and the image-side surface of the fourth lens element L4 are aspheric. The curvature radius of the object side surface of the fourth lens L4 is R41, the curvature radius of the image side surface of the fourth lens L4 is R42, (R41+ R42)/(R41-R42) satisfies 1 ≦ (R41+ R42)/(R41-R42) ≦ 2, preferably 1.2 ≦ (R41+ R42)/(R41-R42) ≦ 1.8. R41/R42 satisfies 3. ltoreq.R 41/R42. ltoreq.6, and more preferably 4. ltoreq.R 41/R42. ltoreq.5.5.

On the other hand, the optical axis region of the object-side surface L41 of the fourth lens element L4 is convex, and the optical axis region of the image-side surface L42 is convex. The object-side surface and the image-side surface of the fourth lens element L4 are aspheric. The object-side surface and the image-side surface of the fourth lens element L4 are aspheric. The curvature radius of the object side surface of the fourth lens L4 is R41, the curvature radius of the image side surface of the fourth lens L4 is R42, (R41+ R42)/(R41-R42) satisfies 0.2 ≦ (R41+ R42)/(R41-R42) ≦ 1, preferably 0.5 ≦ (R41+ R42)/(R41-R42) ≦ 0.8. R41/R42 satisfies-9. ltoreq.R 41/R42. ltoreq.6, and more preferably-8.5. ltoreq.R 41/R42. ltoreq.7.

The on-axis thickness of the fourth lens L4 is d41, the on-axis distance from the image side surface of the fourth lens L4 to the object side surface of the fifth lens L5 is d42, and d41/d42 satisfies 4. ltoreq. d41/d 42. ltoreq.6, preferably 5. ltoreq. d41/d 42. ltoreq.6, and more preferably satisfies 5.5. ltoreq. d41/d 42. ltoreq.5.9. D41/TTL is more than or equal to 0.05 and less than or equal to 0.2.

The focal length of the fifth lens L5 is f5, the range of f5 is 35mm ≤ f5 ≤ 42mm, preferably 36mm ≤ f5 ≤ 42mm, and more preferably 39mm ≤ f5 ≤ 42 mm. The ratio of the focal length of the fifth lens L5 to the total focal length of the system satisfies f5/f 12 or more, and the spherical aberration and the field curvature of the system can be effectively balanced within the range.

The fifth lens element L5 has positive power and has an object-side surface L51 and an image-side surface L52. The optical axis region of the object-side surface L51 is concave, and the optical axis region of the image-side surface L52 is convex. The object-side surface and the image-side surface of the fifth lens element L5 are aspheric. The curvature radius R51 of the object side surface of the fifth lens L5 and the curvature radius R52 of the image side surface of the fifth lens L5, (R51+ R52)/(R51-R52) satisfy 3 ≦ (R51+ R52)/(R51-R52) 6, preferably 4 ≦ (R51+ R52)/(R51-R52) 5.8. Satisfies 1. ltoreq. R51/R52. ltoreq.2, and more preferably 1.2. ltoreq. R51/R52. ltoreq.1.5.

On the other hand, the fifth lens L5 has positive power and has an object-side surface L51 and an image-side surface L52. The optical axis region of the object-side surface L51 is convex, and the optical axis region of the image-side surface L52 is convex. The object-side surface and the image-side surface of the fifth lens element L5 are aspheric. The radius of curvature R51 of the object side surface of the fifth lens L5 and the radius of curvature R52 of the image side surface of the fifth lens L5, (R51+ R52)/(R51-R52) satisfy 0. ltoreq. R51+ R52)/(R51-R52. ltoreq.1, preferably 0.2. ltoreq. R51+ R52)/(R51-R52. ltoreq.0.6. Satisfies-4. ltoreq. R51/R52. ltoreq. 2, and more preferably-3.5. ltoreq. R51/R52. ltoreq. 3.

The on-axis thickness of the fifth lens L5 is d51, the on-axis distance from the image-side surface of the fifth lens L5 to the object-side surface of the sixth lens L6 is d52, and 1. ltoreq. d51/d 52. ltoreq.2, preferably 1.2. ltoreq. d51/d 52. ltoreq.1.8, is satisfied. D51/TTL is more than or equal to 0.01 and less than or equal to 0.05.

The focal length of the sixth lens L6 is f6, the value range of f6 is-15 mm and f6 and f 11.5mm, preferably-14 mm and f6 and f 11.5 mm. The ratio of the focal length of the sixth lens L6 to the total focal length of the system meets the condition that f6/f is less than or equal to-4 and less than or equal to-3, and in the range, the imaging quality can be improved. Further, the preferable value range is that f6/f is less than or equal to-3.9 and less than or equal to-3.1.

The sixth lens element L6 has negative power and has an object-side surface L61 and an image-side surface L62. The optical axis region of the object-side surface L61 is concave, and the optical axis region of the image-side surface L62 is convex. The object-side surface and the image-side surface of the sixth lens element L6 are aspheric. The radius of curvature R61 of the object-side surface of the sixth lens L6 and the radius of curvature R62 of the image-side surface of the sixth lens L6, (R61+ R62)/(R61-R62) satisfy-5. ltoreq. R61+ R62)/(R61-R62. ltoreq.2, preferably-4. ltoreq. R61+ R62)/(R61-R62. ltoreq.3. Further, 0.1. ltoreq.R 61/R62. ltoreq.1, preferably 0.2. ltoreq.R 61/R62. ltoreq.0.6.

The on-axis thickness of the sixth lens L6 is d61, the on-axis distance from the image side surface of the sixth lens L6 to the object side surface of the seventh lens L7 is d62, and d61/d62 satisfies 1. ltoreq. d61/d 62. ltoreq.2, preferably 1. ltoreq. d61/d 62. ltoreq.1.5. D61/TTL is more than or equal to 0.02 and less than or equal to 0.1, and d21/TTL is more than or equal to 0.03 and less than or equal to 0.05, so that ultra-thinning is realized.

The focal length of the seventh lens L7 is f7, the value range of f7 is 2.5 mm-f 7-3.5 mm, and the preferable value range is 2.7 mm-f 7-3.2 mm. The ratio of the focal length of the seventh lens L7 to the total focal length of the system meets f7/f which is more than or equal to 0.5 and less than or equal to 0.9, and within the range, the imaging quality can be improved. Further, the preferable value range is 0.6-f 7/f-0.9.

The seventh lens element L7 has positive power and has an object-side surface L71 and an image-side surface L72. The optical axis region of the object side face L71 is a convex surface, and the circumferential region is a concave surface; the optical axis region of the image side surface L72 is convex. The object-side surface and the image-side surface of the seventh lens element L7 are aspheric. The radius of curvature R71 of the object side of the seventh lens L7, the radius of curvature R72 of the image side of the seventh lens L7, (R71+ R72)/(R71-R72) satisfy-1. ltoreq. R71+ R72)/(R71-R72). ltoreq.0, preferably-0.8. ltoreq. R71+ R72)/(R71-R72). ltoreq.0.5. In addition, R71/R72 is not less than-0.5 and not more than-0.1.

The on-axis thickness of the seventh lens L7 is d71, the on-axis distance from the image-side surface of the seventh lens L7 to the object-side surface of the eighth lens L8 is d72, and 1. ltoreq. d71/d 72. ltoreq.2, preferably 1.2. ltoreq. d71/d 72. ltoreq.1.7 is satisfied. D71/TTL is more than or equal to 0.05 and less than or equal to 0.15, and ultra-thinning is facilitated.

The focal length of the eighth lens L8 is f8, and the value range of f8 is-4 mm and-3 mm, wherein f8 is not more than-4 mm. The ratio of the focal length of the eighth lens L8 to the total focal length of the system meets the condition that f8/f is more than or equal to-0.95 and less than or equal to-0.5, and in the range, the imaging quality can be improved. Further, the preferable value range is that f8/f is less than or equal to-0.95 and less than or equal to-0.8.

The eighth lens element L8 has negative power and has an object-side surface L81 and an image-side surface L82. The optical axis region of the object-side surface L81 is convex, and the optical axis region of the image-side surface L82 is concave. The object-side surface and the image-side surface of the eighth lens element L8 are aspheric. The curvature radius R81 of the object side surface of the eighth lens L8 and the curvature radius R82 of the image side surface of the eighth lens L8 satisfy 2 ≦ (R81+ R82)/(R81-R82) 2.7, preferably 2.3 ≦ (R81+ R82)/(R81-R82) 2.7. Furthermore, 2.2. ltoreq.R 81/R82. ltoreq.2.5.

The on-axis thickness of the eighth lens L8 is d81, and d81/TTL is more than or equal to 0.05 and less than or equal to 0.1.

The axial thickness and the distance from the object side surface of the first lens L1 to the image side surface of the eighth lens L8 are 4.3 mm ≤ LD ≤ =4.6mm, 0.8 ≤ LD/TTL ≤ 1, and the axial distance from the image side surface of the eighth lens L8 to the imaging surface is 0.8 mm ≤ dp ≤ 1mm, preferably 0.8 mm ≤ dp ≤ 0.9 mm. dp/LD is more than or equal to 0.15 and less than or equal to 0.2, and dp/TTL is more than or equal to 1.15 and less than or equal to 0.18.

The lens group satisfying the above range can improve the imaging quality, and has light weight, good visual field and high imaging performance.

Drawings

Fig. 1 is a schematic structural view of an optical imaging lens according to a first embodiment of the present application;

fig. 2 is a schematic structural diagram of an optical imaging lens according to a second embodiment of the present application.

Detailed Description

Embodiments of the present application will be described in detail below with reference to the accompanying drawings, and it will be understood by those skilled in the art that the technical solutions claimed in the present application can be implemented and included based on various changes and modifications of the following embodiments.

Example one

As shown in fig. 1, the present application provides an optical imaging lens, which includes, in order from an object side to an image side, a first lens L1 having positive optical power, a second lens L2 having negative optical power, a third lens L3 having negative optical power, a fourth lens L4 having positive optical power, a fifth lens L5 having positive optical power, a sixth lens L6 having negative optical power, a seventh lens L7 having positive optical power, and an eighth lens L8 having negative optical power. An infrared filter IR and an image plane of an image sensor S are arranged at the image side of the optical imaging lens. In this embodiment, the IR filter IR is disposed between the eighth lens L8 and the imaging plane, and the IR filter IR filters the light passing through the optical imaging lens to a specific wavelength band, for example, to a near infrared wavelength band, so that the wavelength of the near infrared wavelength band is not imaged on the imaging plane.

Specifically, the first lens element L1 has positive power and has an object-side surface L11 and an image-side surface L12. The optical axis region of the object-side surface L11 is convex, and the optical axis region of the image-side surface L22 is concave. The object-side surface and the image-side surface of the first lens element L1 are aspheric.

The second lens element L2 has negative power and has an object-side surface L21 and an image-side surface L22. The optical axis region of the object-side surface L21 is convex, and the optical axis region of the image-side surface L22 is concave. The object-side surface and the image-side surface of the second lens element L2 are aspheric.

The third lens element L3 has negative power and has an object-side surface L31 and an image-side surface L32. The optical axis region of the object-side surface L31 is convex, and the optical axis region of the image-side surface L32 is concave. The object-side surface and the image-side surface of the third lens element L3 are aspheric.

The fourth lens element L4 has positive power and has an object-side surface L41 and an image-side surface L42. The optical axis region of the object-side surface L41 is concave, and the optical axis region of the image-side surface L42 is convex. The object-side surface and the image-side surface of the fourth lens element L4 are aspheric.

The fifth lens element L5 has positive power and has an object-side surface L51 and an image-side surface L52. The optical axis region of the object-side surface L51 is concave, and the optical axis region of the image-side surface L52 is convex. The object-side surface and the image-side surface of the fifth lens element L5 are aspheric.

The sixth lens element L6 has negative power and has an object-side surface L61 and an image-side surface L62. The optical axis region of the object-side surface L61 is concave, and the optical axis region of the image-side surface L62 is convex. The object-side surface and the image-side surface of the sixth lens element L6 are aspheric.

The seventh lens element L7 has positive power and has an object-side surface L71 and an image-side surface L72. The optical axis region of the object side face L71 is a convex surface, and the circumferential region is a concave surface; the optical axis region of the image side surface L72 is convex. The object-side surface and the image-side surface of the seventh lens element L7 are aspheric.

The eighth lens element L8 has negative power and has an object-side surface L81 and an image-side surface L82. The optical axis region of the object-side surface L81 is convex, and the optical axis region of the image-side surface L82 is concave. The object-side surface and the image-side surface of the eighth lens element L8 are aspheric.

In the first embodiment, the total focal length f =3.549mm, the total optical length TTL =5.064mm, the half field angle is 40.6 °, and the IMGH is 3.06 mm.

The focal length f1=3.591mm, f1/f =1.012 of the first lens L1. The radius of curvature of the object-side face L11 of the first lens L1 is R11, and the radius of curvature of the image-side face L12 of the first lens L1 is R12, (R11+ R12)/(R11-R12) = -1.05, and R11/R12= 0.023. The on-axis thickness of the first lens L1 is d11, the on-axis distance from the image-side surface L12 of the first lens L1 to the object-side surface L21 of the second lens L2 is d12, d11/d12=17.03, and d11/TTL = 0.104.

The focal length f2= -5.397mm, f2/f = -1.52 of the second lens L2. The curvature radius of the object-side surface of the second lens L2 is R21, and the curvature radius of the image-side surface of the second lens L2 is R22, (R21+ R22)/(R21-R22) =2.74, and R21/R22= 2.148. The on-axis thickness of the second lens L2 is d21, the on-axis distance from the image-side surface of the second lens L2 to the object-side surface of the third lens L3 is d22, d21/d22=1.96, and d21/TTL = 0.079.

The focal length f3= -138.066mm, f3/f = -38.9 of the third lens L3. The radius of curvature of the object-side surface of the third lens L3 is R31, and the radius of curvature of the image-side surface of the third lens L3 is R32, (R31+ R32)/(R31-R32) =11.99, and R31/R32= 1.182. The on-axis thickness of the third lens L3 is d31, the on-axis distance from the image-side surface of the third lens L3 to the object-side surface of the fourth lens L4 is d32, d31/d32=1.068, and d31/TTL = 0.04.

The focal length f4 =17.614mm, f4/f =4.963 of the fourth lens L4. The radius of curvature of the object-side surface of the fourth lens L4 is R41, and the radius of curvature of the image-side surface of the fourth lens L4 is R42, (R41+ R42)/(R41-R42) =1.45, and R41/R42= 5.48. The on-axis thickness of the fourth lens L4 is d41, and the on-axis distance from the image-side surface of the fourth lens L4 to the object-side surface of the fifth lens L5 is d42, d41/d42=5.854, and d41/TTL = 0.103.

The fifth lens L5 has a focal length f5=39.037mm, and f5/f =11. The radius of curvature R51 of the object-side surface of the fifth lens L5, the radius of curvature R52 of the image-side surface of the fifth lens L5, (R51+ R52)/(R51-R52) =5.5, and R51/R52= 1.444. The on-axis thickness of the fifth lens L5 is d51, and the on-axis distance from the image-side surface of the fifth lens L5 to the object-side surface of the sixth lens L6 is d52, d51/d52=1.35, and d51/TTL = 0.038.

The sixth lens L6 has a focal length f6= -11.545mm, and f6/f = -3.25. The curvature radius R61 of the object side surface of the sixth lens L6, the curvature radius R62 of the image side surface of the sixth lens L6, (R61+ R62)/(R61-R62) = -3.26, and R61/R62= 0.531. The on-axis thickness of the sixth lens L6 is d61, and the on-axis distance from the image-side surface of the sixth lens L6 to the object-side surface of the seventh lens L7 is d62, d61/d62=1.268, and d61/TTL = 0.037.

The seventh lens L7 has a focal length f7=2.888mm, and f7/f = 0.814. The curvature radius R71 of the object side surface of the seventh lens L7, the curvature radius R72 of the image side surface of the seventh lens L7, (R71+ R72)/(R71-R72) = -0.714, and R71/R72= -0.167. The on-axis thickness of the seventh lens L7 is d71, and the on-axis distance from the image-side surface of the seventh lens L7 to the object-side surface of the eighth lens L8 is d72, d71/d72=1.513, and d71/TTL = 0.119.

The eighth lens L8 has a focal length f8= -3.238mm, and f8/f = -0.912. The radius of curvature R81 of the object-side surface of the eighth lens L8, the radius of curvature R82 of the image-side surface of the eighth lens L8, (R81+ R82)/(R81-R82) =2.523, and R81/R82= 2.313. The eighth lens L8 has an on-axis thickness of d81, d81/TTL = 0.093.

The on-axis thickness and distance LD =4.563mm from the object-side surface of the first lens L1 to the image-side surface of the eighth lens L8, LD/TTL =0.901, the on-axis distance dp =0.816mm from the image-side surface of the eighth lens L8 to the imaging surface, dp/LD =0.179, dp/TTL = 0.16.

Watch 1

Example two

As shown in fig. 2, the present application provides an optical imaging lens, which includes, in order from an object side to an image side, a first lens L1 having positive optical power, a second lens L2 having negative optical power, a third lens L3 having negative optical power, a fourth lens L4 having positive optical power, a fifth lens L5 having positive optical power, a sixth lens L6 having negative optical power, a seventh lens L7 having positive optical power, and an eighth lens L8 having negative optical power. An infrared filter IR and an image plane of an image sensor S are arranged at the image side of the optical imaging lens. In this embodiment, the IR filter IR is disposed between the eighth lens L8 and the imaging plane, and the IR filter IR filters the light passing through the optical imaging lens to a specific wavelength band, for example, to a near infrared wavelength band, so that the wavelength of the near infrared wavelength band is not imaged on the imaging plane.

Specifically, the first lens element L1 has positive power and has an object-side surface L11 and an image-side surface L12. The optical axis region of the object-side surface L11 is convex, and the optical axis region of the image-side surface L22 is convex. The object-side surface and the image-side surface of the first lens element L1 are aspheric.

The second lens element L2 has negative power and has an object-side surface L21 and an image-side surface L22. The optical axis region of the object-side surface L21 is concave, and the optical axis region of the image-side surface L22 is concave. The object-side surface and the image-side surface of the second lens element L2 are aspheric.

The fourth lens element L4 has positive power and has an object-side surface L41 and an image-side surface L42. The optical axis region of the object-side surface L41 is convex, and the optical axis region of the image-side surface L42 is convex. The object-side surface and the image-side surface of the fourth lens element L4 are aspheric.

The fifth lens element L5 has positive power and has an object-side surface L51 and an image-side surface L52. The optical axis region of the object-side surface L51 is convex, and the optical axis region of the image-side surface L52 is convex. The object-side surface and the image-side surface of the fifth lens element L5 are aspheric.

In the second embodiment, the total focal length f =4.031mm, the total optical length TTL =5.263mm, the half field angle is 40.5 °, and the IMGH is 3.44 mm.

The focal length f1=3.775mm, f1/f =0.94 of the first lens L1. The radius of curvature of the object side L11 of the first lens L1 is R11, and the radius of curvature of the image side L12 of the first lens L1 is R12, (R11+ R12)/(R11-R12) = -0.934, and R11/R12= -0.034. The on-axis thickness of the first lens L1 is d11, the on-axis distance from the image-side surface L12 of the first lens L1 to the object-side surface L21 of the second lens L2 is d12, d11/d12=17.23, and d11/TTL = 0.101.

The focal length f2= -5.651mm, f2/f = -1.402 of the second lens L2. The curvature radius of the object-side surface of the second lens L2 is R21, and the curvature radius of the image-side surface of the second lens L2 is R22, (R21+ R22)/(R21-R22) =0.95, and R21/R22= -38.96. The on-axis thickness of the second lens L2 is d21, the on-axis distance from the image-side surface of the second lens L2 to the object-side surface of the third lens L3 is d22, d21/d22=2.03, and d21/TTL = 0.078.

The focal length f3= -133.998mm, f3/f = -33.242 of the third lens L3. The radius of curvature of the object-side surface of the third lens L3 is R31, and the radius of curvature of the image-side surface of the third lens L3 is R32, (R31+ R32)/(R31-R32) =10.58, and R31/R32= 1.209. The on-axis thickness of the third lens L3 is d31, and the on-axis distance from the image-side surface of the third lens L3 to the object-side surface of the fourth lens L4 is d32, d31/d32=1.23, and d31/TTL = 0.045.

The focal length f4 =15.722mm, f4/f =3.9 of the fourth lens L4. The radius of curvature of the object-side surface of the fourth lens L4 is R41, and the radius of curvature of the image-side surface of the fourth lens L4 is R42, (R41+ R42)/(R41-R42) =0.78, and R41/R42= -8.23. The on-axis thickness of the fourth lens L4 is d41, and the on-axis distance from the image-side surface of the fourth lens L4 to the object-side surface of the fifth lens L5 is d42, d41/d42=5.52, and d41/TTL = 0.09.

The fifth lens L5 has a focal length f5=41.619mm, and f5/f = 10.324. The radius of curvature R51 of the object-side surface of the fifth lens L5, the radius of curvature R52 of the image-side surface of the fifth lens L5, (R51+ R52)/(R51-R52) =0.5115, and R51/R52= -3.094. The on-axis thickness of the fifth lens L5 is d51, and the on-axis distance from the image-side surface of the fifth lens L5 to the object-side surface of the sixth lens L6 is d52, d51/d52=1.634, and d51/TTL = 0.044.

The sixth lens L6 has a focal length f6= -13.242mm, and f6/f = -3.285. The curvature radius R61 of the object side surface of the sixth lens L6, the curvature radius R62 of the image side surface of the sixth lens L6, (R61+ R62)/(R61-R62) = -3.556, and R61/R62= 0.561. The on-axis thickness of the sixth lens L6 is d61, and the on-axis distance from the image-side surface of the sixth lens L6 to the object-side surface of the seventh lens L7 is d62, d61/d62=1.443, and d61/TTL = 0.041.

The seventh lens L7 has a focal length f7=3.188mm, and f7/f = 0.791. The curvature radius R71 of the object side surface of the seventh lens L7, the curvature radius R72 of the image side surface of the seventh lens L7, (R71+ R72)/(R71-R72) = -0.652, and R71/R72= -0.21. The on-axis thickness of the seventh lens L7 is d71, the on-axis distance from the image-side surface of the seventh lens L7 to the object-side surface of the eighth lens L8 is d72, d71/d72=1.467, and d71/TTL = 0.111.

The eighth lens L8 has a focal length f8= -3.125mm, and f8/f = -0.775. A radius of curvature R81 of the object-side surface of the eighth lens L8, a radius of curvature R82 of the image-side surface of the eighth lens L8, (R81+ R82)/(R81-R82) =2.527, and R81/R82= 2.31. The eighth lens L8 has an on-axis thickness of d81, d81/TTL = 0.097.

The on-axis thickness and distance LD =4.421mm from the object-side surface of the first lens L1 to the image-side surface of the eighth lens L8, LD/TTL =0.84, the on-axis distance dp =0.842mm from the image-side surface of the eighth lens L8 to the imaging surface, dp/LD =0.19, dp/TTL = 0.16.

Watch two

It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific embodiments for carrying out the present application, and that various changes in form and details may be made therein without departing from the spirit and scope of the present application in practice.

Claims

1. An optical imaging lens, comprising, in order from an object side to an imaging side: a first lens L1 having positive power, a second lens L2 having negative power, a third lens L3 having negative power, a fourth lens L4 having positive power, a fifth lens L5 having positive power, a sixth lens L6 having negative power, a seventh lens L7 having positive power, an eighth lens L8 having negative power;

the imaging lens satisfies the following relation: f is more than or equal to 2mm and less than or equal to 5mm, TTL is more than or equal to 4.8mm and less than or equal to 5.5mm, HFOV is more than or equal to 40 degrees and less than or equal to 50 degrees, F-NUMBER <1.8, F1/F is more than or equal to 0.2, F2/F is more than or equal to-1, F3/F is more than or equal to-20 degrees, F4/F is more than or equal to 3, F5/F is more than or equal to 1.8, F6/F is more than or equal to 3, F7/F is more than or equal to 0.5, F369 is more than or equal to 0.95 and less than or equal to F8/F is more than or equal to 0.5, wherein the system focal length of the optical imaging lens is F, the focal length of the first lens L1 is F1, the focal length of the second lens L2 is F2, the focal length of the third lens L3 is F5, the focal length of the fourth lens L4 is F4, the focal length of the fifth lens L5, the sixth lens is F5, the focal length of the eighth lens is 8628, the focal length of the seventh lens F8, the focal length of the seventh lens is F849, the seventh lens 7F 8, the optical imaging lens has total optical length TTL and half field angle HFOV.

2. The optical imaging lens of claim 1, wherein the first lens satisfies the following relationship:

f1 is more than or equal to 3mm and less than or equal to 4mm, R11+ R12)/(R11-R12 is more than or equal to-0.8 is more than or equal to 1.2, the curvature radius of the L11 of the object side surface of the first lens L1 is R11, and the curvature radius of the L12 of the image side surface of the first lens L1 is R12.

3. The optical imaging lens of claim 2, wherein the first lens further satisfies the following relationship: d11/d12 is more than or equal to 15 and less than or equal to 20, d11/TTL is more than or equal to 0.05 and less than or equal to 0.2, the axial thickness of the first lens L1 is d11, and the axial distance from the image side surface L12 of the first lens L1 to the object side surface L21 of the second lens L2 is d 12.

4. The optical imaging lens of claim 1, wherein the second lens satisfies the following relationship: f2 is more than or equal to 6mm and less than or equal to-5 mm, d21/TTL is more than or equal to 0.02 and less than or equal to 0.1, and the on-axis thickness of the second lens L2 is d 21.

5. The optical imaging lens of claim 4, wherein the optical axis area of the object-side surface L21 of the second lens L2 is convex, the optical axis area of the image-side surface L22 is concave, 2 ≦ (R21+ R22)/(R21-R22) ≦ 3, 1.5 ≦ R21/R22 ≦ 3, the radius of curvature of the object-side surface of the second lens L2 is R21, and the radius of curvature of the image-side surface of the second lens L2 is R22.

6. The optical imaging lens of claim 4, wherein the optical axis area of the object-side face L21 of the second lens L2 is concave, the optical axis area of the image-side face L22 is concave, 0 ≦ (R21+ R22)/(R21-R22) ≦ 2, -45 ≦ R21/R22 ≦ -35, the radius of curvature of the object-side face of the second lens L2 is R21, and the radius of curvature of the image-side face of the second lens L2 is R22.

7. The optical imaging lens of claim 1, wherein the third lens satisfies the following relationship: f3 is more than or equal to 150mm and less than or equal to 120mm, R31+ R32)/(R31-R32 is more than or equal to 5mm and less than or equal to 20, R31/R32 is more than or equal to 1 and less than or equal to 2, the radius of curvature of the object-side surface of the third lens L3 is R31, and the radius of curvature of the image-side surface of the third lens L3 is R32.

8. The optical imaging lens of claim 7, wherein the third lens further satisfies the following relationship: 1 is more than or equal to d31/d32 is more than or equal to 5, 0.02 is more than or equal to d31/TTL is more than or equal to 0.1, the on-axis thickness of the third lens L3 is d31, and the on-axis distance from the image-side surface of the third lens L3 to the object-side surface of the fourth lens L4 is d 32.

9. The optical imaging lens of claim 1, wherein the fourth lens satisfies the following relationship: f4 is more than or equal to 10mm and less than or equal to 18mm, d41/d42 is more than or equal to 4mm and less than or equal to 6, d41/TTL is more than or equal to 0.05 and less than or equal to 0.2, the axial thickness of the fourth lens L4 is d41, and the axial distance from the image-side surface of the fourth lens L4 to the object-side surface of the fifth lens L5 is d 42.

10. The optical imaging lens of claim 9, wherein the optical axis area of the object-side surface L41 of the fourth lens L4 is concave, the optical axis area of the image-side surface L42 is convex, 1 ≦ (R41+ R42)/(R41-R42) ≦ 2, 3 ≦ R41/R42 ≦ 6, the radius of curvature of the object-side surface of the fourth lens L4 is R41, and the radius of curvature of the image-side surface of the fourth lens L4 is R42.

11. The optical imaging lens of claim 9, wherein the optical axis area of the object-side face L41 of the fourth lens L4 is convex, the optical axis area of the image-side face L42 is convex, 0.2 ≦ (R41+ R42)/(R41-R42) ≦ 1, -9 ≦ R41/R42 ≦ -6, the radius of curvature of the object-side face of the fourth lens L4 is R41, and the radius of curvature of the image-side face of the fourth lens L4 is R42.

12. The optical imaging lens according to claim 1, characterized in that the fifth lens satisfies the following relation: f5 is more than or equal to 35mm and less than or equal to 42mm, d51/d52 is more than or equal to 1 and less than or equal to 2, d51/TTL is more than or equal to 0.01 and less than or equal to 0.05, the axial thickness of the fifth lens L5 is d51, and the axial distance from the image-side surface of the fifth lens L5 to the object-side surface of the sixth lens L6 is d 52.

13. The optical imaging lens of claim 12, wherein the optical axis area of the object-side face L51 of the fifth lens element is concave, the optical axis area of the image-side face L52 is convex, 3 ≦ (R51+ R52)/(R51-R52) ≦ 6, 1 ≦ R51/R52 ≦ 2, the radius of curvature R51 of the object-side face of the fifth lens element L5, and the radius of curvature R52 of the image-side face of the fifth lens element L5.

14. The optical imaging lens of claim 12, characterized in that the optical axis area of the object-side face L51 of the fifth lens is convex, the optical axis area of the image-side face L52 is convex, 0 ≦ (R51+ R52)/(R51-R52) ≦ 1, -4 ≦ R51/R52 ≦ -2, the radius of curvature R51 of the object-side face of the fifth lens L5, the radius of curvature R52 of the image-side face of the fifth lens L5.

15. The optical imaging lens according to claim 1, characterized in that the sixth lens satisfies the following relation:

f6 is more than or equal to 15mm and less than or equal to-11.5 mm, R61+ R62)/(R61-R62 is more than or equal to 5 and less than or equal to-2, R61/R62 is more than or equal to 0.1 and less than or equal to 1, the curvature radius R61 of the object side surface of the sixth lens L6, and the curvature radius R62 of the image side surface of the sixth lens L6.

16. The optical imaging lens of claim 15, characterized in that the sixth lens further satisfies the following relation: 1 is more than or equal to d61/d62 is more than or equal to 2, 0.02 is more than or equal to d61/TTL is more than or equal to 0.1, the on-axis thickness of the sixth lens L6 is d61, and the on-axis distance from the image-side surface of the sixth lens L6 to the object-side surface of the seventh lens L7 is d 62.

17. The optical imaging lens of claim 1, wherein the seventh lens satisfies the following relationship:

f7 is more than or equal to 2.5mm and less than or equal to 3.5mm, R71+ R72)/(R71-R72 is more than or equal to 1 and less than or equal to 0, R71/R72 is more than or equal to 0.5 and less than or equal to 0.1, the curvature radius R71 of the object side surface of the seventh lens L7 and the curvature radius R72 of the image side surface of the seventh lens L7.

18. The optical imaging lens of claim 17, characterized in that the seventh lens further satisfies the following relation: the on-axis thickness of the seventh lens L7 is d71, the on-axis distance from the image side surface of the seventh lens L7 to the object side surface of the eighth lens L8 is d72, and the requirements that d71/d72 is more than or equal to 1 and less than or equal to 2 and d71/TTL is more than or equal to 0.05 and less than or equal to 0.15 are met.

19. The optical imaging lens of claim 1, wherein the eighth lens satisfies the following relationship:

f8 is not less than 4mm and not more than-3 mm, R81+ R82)/(R81-R82) is not less than 2mm and not more than 3, R81/R82 is not less than 2.2 and not more than 2.5, the radius of curvature R81 of the object side surface of the eighth lens L8, and the radius of curvature R82 of the image side surface of the eighth lens L8.

20. The optical imaging lens of claim 19, characterized in that the eighth lens L8 has an on-axis thickness d81, 0.05 ≦ d81/TTL ≦ 0.1.