Optical imaging system

Patent metadata

Field	Value
Publication number	US-12189097-B2
Application number	US-202117547138-A
Country	US
Kind code	B2
Filing date	Dec 9, 2021
Priority date	Dec 29, 2020
Publication date	Jan 7, 2025
Grant date	Jan 7, 2025

Abstract

Embodiments of the present disclosure disclose an optical imaging system, comprising, sequentially from an object side to an image side along an optical axis: a prism, reflecting light incident to the prism along a first direction, to cause the light to emerge from the prism along a second direction, and a stop, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens sequentially from the prism to an image side along the second direction, each of the first lens to the seventh lens has a refractive power. A total effective focal length f of the optical imaging system and an entrance pupil diameter EPIC of the optical imaging system satisfy: f/EPD<1.4.

First claim

What is claimed is:

1. An optical imaging system, comprising:
a prism, reflecting light incident to the prism along a first direction, to cause the light to emerge from the prism along a second direction; and
the optical imaging system further comprising, sequentially from the prism to an image side along the second direction: a stop, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens,
wherein each of the first lens to the seventh lens has a refractive power; and
a total effective focal length f of the optical imaging system and an entrance pupil diameter EPD of the optical imaging system satisfy: f/EPD<1.4,
wherein the second lens has a positive refractive power;
an object-side surface of the fourth lens is a convex surface, an image-side surface of the fourth lens is a concave surface; and
an image-side surface of the sixth lens is a concave surface.

2. The optical imaging system according to claim 1 , wherein an effective focal length f1 of the first lens, an effective focal length f3 of the third lens, and an effective focal length f7 of the seventh lens satisfy: −1.5<(f1+f7)/f3<0.

3. The optical imaging system according to claim 1 , wherein an effective focal length f2 of the second lens and the total effective focal length f of the optical imaging system satisfy: 0.6<f2/f<1.

4. The optical imaging system according to claim 1 , wherein a radius of curvature R1 of an object-side surface of the first lens, a radius of curvature R2 of an image-side surface of the first lens, and a radius of curvature R3 of an object-side surface of the second lens satisfy: 0.2<R3/(R1+R2)<0.5.

5. The optical imaging system according to claim 1 , wherein a center thickness CT1 of the first lens on an optical axis and a center thickness CT2 of the second lens on the optical axis satisfy: 0.4<CT1/CT2<1.1.

6. The optical imaging system according to claim 1 , wherein a center thickness CT4 of the fourth lens on an optical axis, a center thickness CT5 of the fifth lens on the optical axis, and a spacing distance T45 between the fourth lens and the fifth lens on the optical axis satisfy: 1.4<(CT4+CT5)/T45<2.6.

7. The optical imaging system according to claim 1 , wherein a radius of curvature R7 of an object-side surface of the fourth lens, a radius of curvature R8 of an image-side surface of the fourth lens, and the total effective focal length f of the optical imaging system satisfy: 0.8<(R7+R8)/f<1.3.

8. The optical imaging system according to claim 1 , wherein a distance TTL from an object-side surface of the first lens to an image plane of the optical imaging system on an optical axis and the total effective focal length f of the optical imaging system satisfy: TTL/f≤1.15.

9. The optical imaging system according to claim 1 , wherein half of a maximal field-of-view Semi-FOV of the optical imaging system satisfies: 20°<Semi-FOV<30°.

10. An optical imaging system, comprising:
a prism, reflecting light incident to the prism along a first direction, to cause the light to emerge from the prism along a second direction; and
the optical imaging system further comprising, sequentially from the prism to an image side along the second direction: a stop, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens, and a seventh lens,
wherein the second lens has a positive refractive power;
an object-side surface of the fourth lens is a convex surface, an image-side surface of the fourth lens is a concave surface; and
an image-side surface of the sixth lens is a concave surface,
wherein a center thickness CT4 of the fourth lens on an optical axis, a center thickness CT5 of the fifth lens on the optical axis, and a spacing distance T45 between the fourth lens and the fifth lens on the optical axis satisfy: 1.4<(CT4+CT5)/T45<2.6.

11. The optical imaging system according to claim 10 , wherein an effective focal length f2 of the second lens and a total effective focal length f of the optical imaging system satisfy: 0.6<f2/f<1.

12. The optical imaging system according to claim 10 , wherein a radius of curvature R1 of an object-side surface of the first lens, a radius of curvature R2 of an image-side surface of the first lens, and a radius of curvature R3 of an object-side surface of the second lens satisfy: 0.2<R3/(R1+R2)<0.5.

13. The optical imaging system according to claim 10 , wherein a center thickness CT1 of the first lens on an optical axis and a center thickness CT2 of the second lens on the optical axis satisfy: 0.4<CT1/CT2<1.1.

14. The optical imaging system according to claim 10 , wherein a radius of curvature R7 of the object-side surface of the fourth lens, a radius of curvature R8 of the image-side surface of the fourth lens, and a total effective focal length f of the optical imaging system satisfy: 0.8<(R7+R8)/f<1.3.

15. The optical imaging system according to claim 10 , wherein an effective focal length f1 of the first lens, an effective focal length f3 of the third lens, and an effective focal length f7 of the seventh lens satisfy: −1.5<(f1+f7)/f3<0.

16. The optical imaging system according to claim 10 , wherein a distance TTL from an object-side surface of the first lens to an image plane of the optical imaging system on an optical axis and a total effective focal length f of the optical imaging system satisfy: TTL/f≤1.15.

17. The optical imaging system according to claim 10 , wherein half of a maximal field-of-view Semi-FOV of the optical imaging system satisfies: 20°<Semi-FOV<30°.

18. The optical imaging system according to claim 10 , wherein a total effective focal length f of the optical imaging system and an entrance pupil diameter EPD of the optical imaging system satisfy: f/EPD<1.4.

Assignees

• Zhejiang Sunny Optics Co Ltd

Inventors

• Li Jianlin
• Li Yang
• Xing Tianxiang
• He Lingbo
• Huang Lin
• Dai Fujian
• Zhao Liefeng

Classifications

• G02B13/0045 Primary

  having five or more lenses · CPC title

• G02B9/64

  having more than six components · CPC title

• G02B13/0065 Primary

  having a beam-folding prism or mirror · CPC title

• G02B13/02 Primary

  Telephoto objectives, i.e. systems of the type + - in which the distance from the front vertex to the image plane is less than the equivalent focal length · CPC title