Optical lens

Patent metadata

Field	Value
Publication number	US-10466449-B2
Application number	US-201615375618-A
Country	US
Kind code	B2
Filing date	Dec 12, 2016
Priority date	Dec 15, 2015
Publication date	Nov 5, 2019
Grant date	Nov 5, 2019

Abstract

An optical lens includes a first lens group with a negative refractive power, an aperture stop, and a second lens group with a positive refractive power. The first lens group includes a first aspheric lens and a second aspheric lens. The optical lens satisfies the conditions: 3.5>RT1>2.5 and 3.5>RT2>2.6, where RT1 is a ratio of a maximum axial thickness to a minimum axial thickness within a clear aperture of the first aspheric lens, and RT2 is a ratio of a maximum axial thickness to a minimum axial thickness within a clear aperture of the second aspheric lens.

First claim

What is claimed is:

1. An optical lens, comprising:
a first lens group disposed between a magnified side and a minified side, the first lens group having a negative refractive power and having a first aspheric lens and a second aspheric lens;
a second lens group disposed between the first lens group and the minified side and having a positive refractive power; and
an aperture stop disposed between the first lens group and the second lens group, wherein the optical lens satisfies:
3.5>RT1>2.5;
3.5>RT2>2.6; and
0.77>f/H>0.6, where f is an effective focal length of the optical lens, H is a maximum image height of an image formed by the optical lens at the minified side, RT1 is a ratio of a maximum thickness to a minimum thickness within a clear aperture of the first aspheric lens, RT2 is a ratio of a maximum thickness to a minimum thickness within a clear aperture of the second aspheric lens, and the maximum thickness and the minimum thickness are respectively a maximum value and a minimum value among thickness values measured in the direction of an optical axis of the optical lens.

2. The optical lens as claimed in claim 1 , wherein the optical lens comprises, in order from the magnified side to the minified side, the first aspheric lens, the second aspheric lens, a third lens, a fourth lens, a fifth lens and a sixth lens, and refractive powers of the first aspheric lens to the sixth lens are negative, negative, positive, negative, positive, positive.

3. The optical lens as claimed in claim 2 , wherein the second aspheric lens is a biconcave lens and the fourth lens is a meniscus lens, or the second aspheric lens is a meniscus lens and the fourth lens is a bi-concave lens.

4. The optical lens as claimed in claim 1 , wherein an F number the optical lens is larger than 1.8.

5. The optical lens as claimed in claim 1 , wherein a maximum optical distortion of the optical lens is less than 15%.

6. The optical lens as claimed in claim 1 , wherein a magnified-side surface of the first aspheric lens comprises a center region overlapping the optical axis and an a periphery region away from the optical axis, and the center region is concave towards the minified side to form at least one inflection point on the border between the center region and the periphery region.

7. An optical lens, comprising:
a first lens group disposed between a magnified side and a minified side, the first lens group having a negative refractive power and having a first aspheric lens and a second aspheric lens;
a second lens group disposed between the first lens group and the minified side and having a positive refractive power; and
an aperture stop disposed between the first lens group and the second lens group, wherein a magnified-side surface of the first aspheric lens comprises a center region overlapping an optical axis and an a periphery region away from the optical axis, the center region is concave towards the minified side to form at least one inflection point on the border between the center region and the periphery region, and the optical lens satisfies:
0<|H/(f*tan(x))−1|<0.15, where f is an effective focal length of the optical lens, H is a maximum image height of an image formed by the optical lens at the minified side, and x is a maximum half field angle.

8. The optical lens as claimed in claim 7 , wherein the optical lens comprises, in order from the magnified side to the minified side, the first aspheric lens, the second aspheric lens, a third lens, a fourth lens, a fifth lens and a sixth lens, and refractive powers of the first aspheric lens to the sixth lens are negative, negative, positive, negative, positive, positive.

9. The optical lens as claimed in claim 8 , wherein the second aspheric lens is a bi-concave lens and the fourth lens is a meniscus lens, or the second aspheric lens is a meniscus lens and the fourth lens is a bi-concave lens.

10. The optical lens as claimed in claim 7 , wherein an F number the optical lens is larger than 1.8.

11. The optical lens as claimed in claim 7 , wherein a maximum optical distortion of the optical lens is less than 15%.

12. An optical lens, comprising:
a first lens group disposed between a magnified side and a minified side, the first lens group having a negative refractive power and having a first aspheric lens;
a second lens group disposed between the first lens group and the minified side and having a positive refractive power; and
an aperture stop disposed between the first lens group and the second lens group, wherein the optical lens satisfies:
3.5>RT1>2.5; and
8>CA/f>5, where CA is a clear aperture of the first aspheric lens, RT1 is a ratio of a maximum thickness to a minimum thickness within the clear aperture of the first aspheric lens, the maximum thickness and the minimum thickness are respectively a maximum value and a minimum value among thickness values measured in the direction of an optical axis of the optical lens, and f is an effective focal length of the optical lens.

13. The optical lens as claimed in claim 12 , wherein the first lens group further comprises a second aspheric lens disposed on one side of the first aspheric lens.

14. The optical lens as claimed in claim 13 , wherein the optical lens comprises, in order from the magnified side to the minified side, the first aspheric lens, the second aspheric lens, a third lens, a fourth lens, a fifth lens and a sixth lens, and refractive powers of the first aspheric lens to the sixth lens are negative, negative, positive, negative, positive, positive.

15. The optical lens as claimed in claim 14 , wherein the sixth lens is an aspheric lens.

16. The optical lens as claimed in claim 14 , wherein the second aspheric lens is a bi-concave lens and the fourth lens is a meniscus lens, or the second aspheric lens is a meniscus lens and the fourth lens is a bi-concave lens.

17. The optical lens as claimed in claim 12 , wherein an F number the optical lens is larger than 1.8.

18. The optical lens as claimed in claim 12 , wherein a maximum optical distortion of the optical lens is less than 15%.

19. The optical lens as claimed in claim 12 , wherein a magnified-side surface of the first aspheric lens comprises a center region overlapping the optical axis and an a periphery region away from the axis, and the center region is concave towards the minified side to form at least one inflection point on the border between the center region and the periphery region.

Assignees

• Young Optics Inc

Inventors

• Jiang Sheng-Da
• Chou Yu-Hung

Classifications

• G02B13/04 Primary

  Reversed telephoto objectives · CPC title

• G02B27/0025

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

• G02B13/06 Primary

  Panoramic objectives; So-called "sky lenses" {including panoramic objectives having reflecting surfaces} · CPC title

• G02B9/10

  one + and one - component · 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