Optical imaging system

Patent metadata

Field	Value
Publication number	US-10996435-B2
Application number	US-201715772854-A
Country	US
Kind code	B2
Filing date	Sep 21, 2017
Priority date	May 15, 2017
Publication date	May 4, 2021
Grant date	May 4, 2021

Abstract

The present disclosure discloses an optical imaging system, the optical imaging system having an effective focal length f and an entrance pupil diameter EPD, and comprising sequentially, along an optical axis from an object side to an image side, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens. The third lens has a negative refractive power; the fifth lens has a positive refractive power or a negative refractive power, and an image side surface of the fifth lens is a convex surface; the seventh lens has a positive refractive power or a negative refractive power, and an object side surface of the seventh lens is a concave surface; the first lens, the second lens, the fourth lens, and the sixth lens respectively have a positive refractive power or a negative refractive power.

First claim

What is claimed is:

1. An optical imaging system, having an effective focal length f and an entrance pupil diameter EPD, and the 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, a fourth lens, a fifth lens, a sixth lens and a seventh lens,
wherein an image side surface of the second lens is a convex surface;
the third lens has a negative refractive power;
the fifth lens has a positive refractive power or a negative refractive power, and an image side surface of the fifth lens is a convex surface;
the seventh lens has a positive refractive power or a negative refractive power, and an object side surface of the seventh lens is a concave surface;
the first lens, the second lens, the fourth lens, and the sixth lens respectively have a positive refractive power or a negative refractive power;
a distance TTL from an object side surface of the first lens to an image plane on the optical axis and half of a diagonal length ImgH of an effective pixel area on the image plane of the optical imaging system satisfy: TTL/ImgH<1.6; and
the effective focal length f and the entrance pupil diameter EPD satisfy: f/EPD<1.6.

2. The optical imaging system according to claim 1 , wherein a distance SL from an aperture of the optical imaging system to the image plane on the optical axis and the distance TTL from the object side surface of the first lens to the image plane on the optical axis satisfy: SL/TTL<0.85.

3. The optical imaging system according to claim 1 , wherein a center thickness CT 1 of the first lens on the optical axis, a center thickness CT 2 of the second lens on the optical axis and a center thickness CT 4 of the fourth lens on the optical axis satisfy: 1.5<(CT 1 +CT 2 )/CT 4 <2.3.

4. The optical imaging system according to claim 3 , wherein the center thickness CT 2 of the second lens on the optical axis and the center thickness CT 4 of the fourth lens on the optical axis satisfy: 0.75<CT 2 /CT 4 <1.5.

5. The optical imaging system according to claim 1 , wherein 0<SAG 41 /SAG 42 <0.5,
wherein SAG 41 represents a distance from an intersection point of an object side surface of the fourth lens and the optical axis to an effective radius vertex of the object side surface of the fourth lens on the optical axis; and
SAG 42 represents a distance from an intersection point of an image side surface of the fourth lens and the optical axis to an effective radius vertex of the image side surface of the fourth lens on the optical axis.

6. The optical imaging system according to claim 1 , wherein a combined focal length f12 of the first lens and the second lens and a combined focal length f56 of the fifth lens and the sixth lens satisfy: 0.6<f12/f56<1.2.

7. The optical imaging system according to claim 1 , wherein the half of the diagonal length ImgH of the effective pixel area on the image plane of the optical imaging system and the effective focal length f of the optical imaging system satisfy: 0.8<ImgH/f<1.

8. The optical imaging system according to claim 1 , wherein a spacing distance T 34 between the third lens and the fourth lens on the optical axis and a spacing distance T 45 between the fourth lens and the fifth lens on the optical axis satisfy: 0.5<T 34 /T 45 <1.

9. An optical imaging system, having an effective focal length f and an entrance pupil diameter EPD, and the 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, a fourth lens, a fifth lens, and a plurality of subsequent lenses,
wherein the third lens has a negative refractive power;
the fifth lens has a positive refractive power or a negative refractive power, and an image side surface of the fifth lens is a convex surface;
the first lens, the second lens and the fourth lens respectively have a positive refractive power or a negative refractive power;
a distance SL from an aperture of the optical imaging system to an image plane on the optical axis and a distance TTL from an object side surface of the first lens to the image plane on the optical axis satisfy: SL/TTL<0.85;
the effective focal length f and the entrance pupil diameter EPD satisfy: f/EPD<1.6; and
the distance TTL from the object side surface of the first lens to the image plane on the optical axis and half of a diagonal length ImgH of an effective pixel area on the image plane of the optical imaging system satisfy: TTL/ImgH<1.6.

10. The optical imaging system according to claim 9 , wherein the plurality of subsequent lenses comprise at least a sixth lens and a seventh lens, wherein
the sixth lens has a positive refractive power or a negative refractive power; and
the seventh lens has a positive refractive power or a negative refractive power, and an object side surface of the seventh lens is a concave surface.

11. The optical imaging system according to claim 10 , wherein a combined focal length f12 of the first lens and the second lens and a combined focal length f56 of the fifth lens and the sixth lens satisfy: 0.6<f12/f56<1.2.

12. The optical imaging system according to claim 10 , wherein an effective focal length f5 of the fifth lens and an effective focal length f7 of the seventh lens satisfy: 1.5≤|f5/f7|<2.5.

13. The optical imaging system according to claim 10 , wherein a radius of curvature R 13 of the object side surface of the seventh lens and a radius of curvature R 14 of an image side surface of the seventh lens satisfy: −1.8<R 13 /R 14 <−1.

14. The optical imaging system according to claim 9 , wherein 0<SAG 41 /SAG 42 <0.5,
wherein SAG 41 represents a distance from an intersection point of an object side surface of the fourth lens and the optical axis to an effective radius vertex of the object side surface of the fourth lens on the optical axis; and
SAG 42 represents a distance from an intersection point of an image side surface of the fourth lens and the optical axis to an effective radius vertex of the image side surface of the fourth lens on the optical axis.

15. The optical imaging system according to claim 9 , wherein an effective radius DT 11 of the object side surface of the first lens and an effective radius DT 52 of the image side surface of the fifth lens satisfy: 0.7<DT 11 /DT 52 <1.

16. The optical imaging system according to claim 9 , wherein half of the diagonal length of the effective pixel area on the image plane of the optical imaging system ImgH and the effective focal length f of the optical imaging system satisfy: 0.8<ImgH/f<1.

17. The optical imaging system according to claim 9 , wherein a spacing distance T 34 between the third lens and the fourth lens on the optical axis and a spacing distance T 45 between the fourth lens and the fifth lens on the optical axis satisfy: 0.5<T 34 /T 45 <1.

Assignees

• Zhejiang Sunny Optical Co Ltd

Inventors

• Dai Fujian
• Wenren Jianke

Classifications

• G02B13/0045 Primary

  having five or more lenses · CPC title

• G02B9/64

  having more than six components · CPC title

• G02B9/60

  having five components only · CPC title