Camera lens assembly

Patent metadata

Field	Value
Publication number	US-11137571-B2
Application number	US-201816231092-A
Country	US
Kind code	B2
Filing date	Dec 21, 2018
Priority date	Aug 24, 2017
Publication date	Oct 5, 2021
Grant date	Oct 5, 2021

Abstract

The present disclosure discloses a camera lens assembly. The camera lens assembly includes, sequentially along an optical axis from an object side to an image side, a first lens, a second lens, a third lens, and a fourth lens. An object-side surface of the first lens and an object-side surface of the second lens are convex surfaces. An image-side surface of the third lens is a convex surface. An image-side surface of the fourth lens is a concave surface. Each of the first lens and the third lens has a positive refractive power. Each of the second lens and the fourth lens has a positive refractive power or a negative refractive power. A total effective focal length f of the camera lens assembly and an entrance pupil diameter EPD of the camera lens assembly satisfy: f/EPD<1.5.

First claim

What is claimed is:

1. A camera lens assembly comprising, along an optical axis from an object side to an image side, a first lens, a second lens, a third lens, and a fourth lens in sequence,
wherein an object-side surface of the first lens and an object-side surface of the second lens are convex surfaces;
an image-side surface of the third lens is a convex surface;
an image-side surface of the fourth lens is a concave surface;
each of the first lens and the third lens has a positive refractive power;
each of the second lens and the fourth lens has a positive refractive power or a negative refractive power; and
a total effective focal length f of the camera lens assembly and an entrance pupil diameter EPD of the camera lens assembly satisfy: f/EPD<1.5,
wherein the camera lens assembly has and only has four lenses having refractive power; and
wherein an image-side surface of the second lens is a concave surface, and a radius R 3 of curvature of the object-side surface of the second lens and a radius R 4 of curvature of the image-side surface of the second lens satisfy: 0.5<R 3 /R 4 <1.

2. The camera lens assembly according to claim 1 , wherein the second lens has a positive refractive power, and an effective focal length f 2 of the second lens and the total effective focal length f of the camera lens assembly satisfy: 2<f 2 /f<8.

3. The camera lens assembly according to claim 1 , wherein a radius R 1 of curvature of the object-side surface of the first lens and the total effective focal length f of the camera lens assembly satisfy: 0.5<R 1 /f<1.2.

4. The camera lens assembly according to claim 1 , wherein a spacing distance T 12 along the optical axis between the first lens and the second lens and an axial distance TTL from the object-side surface of the first lens to an image plane of the camera lens assembly satisfy: T 12 /TTL<0.2.

5. The camera lens assembly according to claim 1 , wherein a center thickness CT 1 of the first lens along the optical axis and a center thickness CT 3 of the third lens along the optical axis satisfy: 0.6<CT 1 /CT 3 <1.3.

6. The camera lens assembly according to claim 1 , wherein a center thickness CT 1 of the first lens along the optical axis, a center thickness CT 2 of the second lens along the optical axis, and a center thickness CT 3 of the third lens along the optical axis satisfy: 0.4<CT 1 /(CT 2 +CT 3 )<0.9.

7. The camera lens assembly according to claim 1 , wherein an effective semi-diameter DT 11 of the object-side surface of the first lens and a half ImgH of a diagonal length of an effective pixel area on an image plane of the camera lens assembly satisfy: 0.5<DT 11 /ImgH<1.

8. The camera lens assembly according to claim 1 , wherein an effective semi-diameter DT 42 of the image-side surface of the fourth lens and a half ImgH of a diagonal length of an effective pixel area on an image plane of the camera lens assembly satisfy: 0.7<DT 42 /ImgH<1.

9. The camera lens assembly according to claim 1 , wherein a distance SAG 21 along the optical axis from an intersection point of the object-side surface of the second lens with the optical axis to a vertex of an effective semi-diameter of the object-side surface of the second lens and a center thickness CT 2 of the second lens along the optical axis satisfy: 0<SAG 21 /CT 2 <0.7.

10. The camera lens assembly according to claim 1 , further comprising an infrared bandpass filter disposed between the fourth lens and an image plane.

11. A camera lens assembly comprising, along an optical axis from an object side to an image side, a first lens, a second lens, a third lens, and a fourth lens in sequence, wherein an object-side surface of the first lens is a convex surface; at least one of an object-side surface of the third lens or an image-side surface of the third lens is a convex surface; at least one of an object-side surface of the fourth lens or an image-side surface of the fourth lens is a concave surface; at least two of the first lens, the third lens, and the fourth lens have positive refractive powers; and the second lens has a positive refractive power, and an effective focal length f 2 of the second lens and a total effective focal length f of the camera lens assembly satisfy: 2<f 2 /f<8, wherein the camera lens assembly has and only has four lenses having refractive power; and wherein a radius R 3 of curvature of an object-side surface of the second lens and a radius R 4 of curvature of an image-side surface of the second lens satisfy: 0.5<R 3 /R 4 <1; and a total effective focal length f of the camera lens assembly and an entrance pupil diameter EPD of the camera lens assembly satisfy: f/EPD<1.5.

12. The camera lens assembly according to claim 11 , wherein each of the first lens and the third lens has a positive refractive power.

13. The camera lens assembly according to claim 12 , wherein a center thickness CT 1 of the first lens along the optical axis and a center thickness CT 3 of the third lens along the optical axis satisfy: 0.6<CT 1 /CT 3 <1.3.

14. The camera lens assembly according to claim 11 , wherein the image-side surface of the fourth lens is a concave surface.

15. The camera lens assembly according to claim 11 , wherein an effective semi-diameter DT 11 of the object-side surface of the first lens and a half ImgH of a diagonal length of an effective pixel area on an image plane of the camera lens assembly satisfy: 0.5<DT 11 /ImgH<1.

16. The camera lens assembly according to claim 11 , wherein the object-side surface of the second lens is a convex surface, and the image-side surface of the second lens is a concave surface.

17. The camera lens assembly according to claim 16 , wherein a distance SAG 21 along the optical axis from an intersection point of the object-side surface of the second lens with the optical axis to a vertex of an effective semi-diameter of the object-side surface of the second lens and a center thickness CT 2 of the second lens along the optical axis satisfy: 0<SAG 21 /CT 2 <0.7.

18. The camera lens assembly according to claim 11 , wherein a radius R 1 of curvature of the object-side surface of the first lens and the total effective focal length f of the camera lens assembly satisfy: 0.5<R 1 /f<1.2.

Assignees

• Zhejiang Sunny Optical Co Ltd

Inventors

• Wang Xinquan

Classifications

• G02B13/004 Primary

  having four lenses · CPC title

• G02B9/34 Primary

  having four components only · CPC title

• G02B13/008

  designed for infrared light · CPC title

• G02B13/18

  with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration {(G02B13/002 takes precedence)} · CPC title