Optical imaging system

Patent metadata

Field	Value
Publication number	US-11073678-B2
Application number	US-201716076285-A
Country	US
Kind code	B2
Filing date	Nov 20, 2017
Priority date	Jun 23, 2017
Publication date	Jul 27, 2021
Grant date	Jul 27, 2021

Abstract

The present disclosure discloses an optical imaging system, the optical imaging system including 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. The first lens has a positive refractive power or a negative refractive power, an object-side surface of the first lens is a concave surface, and an image-side surface of the first lens is a convex surface; both the second lens and the third lens have positive refractive powers; and the fourth lens has a positive refractive power or a negative refractive power, wherein an abbe number V1 of the first lens and an abbe number V4 of the fourth lens satisfy: |V1−V4|≤30; and the abbe number V1 of the first lens and an abbe number V2 of the second lens satisfy: 20≤|V1−V2|≤50.

First claim

What is claimed is:

1. An optical imaging system, comprising 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,
wherein the first lens has a positive refractive power or a negative refractive power, an object-side surface of the first lens is a concave surface, and an image-side surface of the first lens is a convex surface;
both the second lens and the third lens have positive refractive powers; and
the fourth lens has a positive refractive power or a negative refractive power,
wherein an abbe number V1 of the first lens and an abbe number V4 of the fourth lens satisfy: |V1−V4|≤30; and
the abbe number V1 of the first lens and an abbe number V2 of the second lens satisfy: 20≤|V1−V2|≤50,
wherein the optical imaging system further comprises an electronic photosensitive element disposed on an image plane of the optical imaging system, and
half of a diagonal length ImgH of an effective pixel area of the electronic photosensitive element and a total effective focal length f of the optical imaging system satisfy: ImgH/f>1.

2. The optical imaging system according to claim 1 , wherein an image-side surface of the third lens is a convex surface, and
a radius of curvature R6 of the image-side surface of the third lens and an effective focal length f3 of the third lens satisfy: −0.8<R6/f3<−0.3.

3. The optical imaging system according to claim 1 , wherein an effective focal length f3 of the third lens and an effective focal length f4 of the fourth lens satisfy: 0.5<|f3/f4|<1.2.

4. The optical imaging system according to claim 1 , wherein a center thickness CT2 of the second lens on the optical axis and a center thickness CT3 of the third lens on the optical axis satisfy: 0.5<CT2/CT3<1.

5. The optical imaging system according to claim 1 , wherein a center thickness CT1 of the first lens on the optical axis and a distance TTL from the object-side surface of the first lens to the image plane on the optical axis satisfy: 0.1<CT1/TTL<0.2.

6. The optical imaging system according to claim 1 , wherein (T23+T34)/T12<0.85,
T12 is a spacing distance between the first lens and the second lens on the optical axis, T23 is a spacing distance between the second lens and the third lens on the optical axis, and T34 is a spacing distance between the third lens and the fourth lens on the optical axis.

7. The optical imaging system according to claim 1 , wherein an effective radius DT12 of the image-side surface of the first lens and the half of the diagonal length ImgH of the effective pixel area of the electronic photosensitive element satisfy: 0.7<DT12/ImgH<1.

8. An optical imaging system, comprising 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,
wherein the first lens has a positive refractive power or a negative refractive power, an object-side surface of the first lens is a concave surface, and an image-side surface of the first lens is a convex surface;
both the second lens and the third lens have positive refractive powers; and
the fourth lens has a positive refractive power or a negative refractive power, and each of an object-side surface and an image-side surface of the fourth lens has at least one inflection point,
wherein an effective radius DT11 of the object-side surface of the first lens and an effective radius DT42 of the image-side surface of the fourth lens satisfy: 1<DT11/DT42<1.4.

9. The optical imaging system according to claim 8 , wherein an image-side surface of the third lens is a convex surface.

10. The optical imaging system according to claim 9 , wherein an abbe number V1 of the first lens and an abbe number V4 of the fourth lens satisfy: |V1−V4|≤30.

11. The optical imaging system according to claim 10 , wherein the abbe number V1 of the first lens and an abbe number V2 of the second lens satisfy: 20≤|V1−V2|≤50.

12. The optical imaging system according to claim 8 , wherein the fourth lens has the negative refractive power.

13. The optical imaging system according to claim 12 , wherein an effective focal length f3 of the third lens and an effective focal length f4 of the fourth lens satisfy: 0.5|f3/f4|<1.2.

14. The optical imaging system according to claim 8 , wherein a center thickness CT2 of the second lens on the optical axis and a center thickness CT3 of the third lens on the optical axis satisfy: 0.5<CT2/CT3<1.

15. The optical imaging system according to claim 8 , wherein (T23+T34)/T12<0.85,
T12 is a spacing distance between the first lens and the second lens on the optical axis, T23 is a spacing distance between the second lens and the third lens on the optical axis, and T34 is a spacing distance between the third lens and the fourth lens on the optical axis.

16. The optical imaging system according to claim 8 , wherein the optical imaging system further comprises an electronic photosensitive element disposed on an image plane of the optical imaging system, and
an effective radius DT12 of the image-side surface of the first lens and half of a diagonal length ImgH of an effective pixel area of the electronic photosensitive element satisfy: 0.7<DT12/ImgH<1.

17. An optical imaging system, having a total effective focal length f, and comprising 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,
wherein both the second lens and the third lens have positive refractive powers;
at least one of the first lens and the fourth lens has a negative refractive power; and
the optical imaging system further comprises an electronic photosensitive element disposed on an image plane of the optical imaging system, and half of a diagonal length ImgH of an effective pixel area of the electronic photosensitive element and the total effective focal length f satisfy: ImgH/f>1,
wherein an effective radius DT11 of an object-side surface of the first lens and an effective radius DT42 of an image-side surface of the fourth lens satisfy: 1<DT11/DT42<1.4.

18. The optical imaging system according to claim 17 , wherein an image-side surface of the third lens is a convex surface.

19. The optical imaging system according to claim 18 , wherein a radius of curvature R6 of the image-side surface of the third lens and an effective focal length f3 of the third lens satisfy: −0.8<R6/f3<−0.3.

20. The optical imaging system according to claim 17 , wherein each of an object-side surface and an image-side surface of the fourth lens has at least one inflection point.

21. The optical imaging system according to claim 17 , wherein the fourth lens has the negative refractive power.

Assignees

• Zhejiang Sunny Optical Co Ltd

Inventors

• Wang Xinquan

Classifications

• H04N23/54

  Mounting of pick-up tubes, electronic image sensors, deviation or focusing coils · 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

• G02B9/34

  having four components only · CPC title

• G02B27/0025

  for optical correction, e.g. distorsion, aberration · CPC title

• G02B9/58 Primary

  arranged - + + - · CPC title