Optical lens assembly and image capturing device

Patent metadata

Field	Value
Publication number	US-10031317-B2
Application number	US-201514680983-A
Country	US
Kind code	B2
Filing date	Apr 7, 2015
Priority date	Feb 4, 2015
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

Abstract

An optical lens assembly includes, in order from an object side to an image side, a first lens element, a second lens element and a third lens element. The first lens element with positive refractive power has an object-side surface being convex, and the object-side surface and an image-side surface thereof are aspheric. The second lens element with negative refractive power has an image-side surface being concave, and an object-side surface and the image-side surface thereof are aspheric. The third lens element with refractive power has an object-side surface being concave, and the object-side surface and an image-side surface thereof are aspheric. The optical lens assembly further includes a stop with no lens element having refractive power disposed between the stop and the first lens element. The optical lens assembly has a total of three lens elements with refractive power.

First claim

What is claimed is:

1. An optical lens assembly comprising, in order from an object side to an image side:
a first lens element with positive refractive power having an object-side surface being convex, wherein the object-side surface and an image-side surface of the first lens element are aspheric;
a second lens element with negative refractive power having an image-side surface being concave, wherein an object-side surface and the image-side surface of the second lens element are aspheric; and
a third lens element having an object-side surface being concave, wherein the object-side surface and an image-side surface of the third lens element are aspheric;
wherein the optical lens assembly has an aperture stop with no lens element disposed between the aperture stop and the first lens element; and
wherein the optical lens assembly has a total of three lens elements; a focal length of the optical lens assembly is f, a curvature radius of the image-side surface of the second lens element is R 4 , a curvature radius of the object-side of the third lens element is R 5 , an axial distance between the aperture stop and the image-side surface of the third lens element is SD, an axial distance between the object-side surface of the first lens element and the image-side surface of the third lens element is TD, a central thickness of the first lens element is CT 1 , a central thickness of the second lens element is CT 2 , and the following conditions are satisfied:
1.25< f/R 4;
−1.0< R 5/ f< 0;

0.6< SD/TD< 1.0;and
0<CT1/CT2≤0.88.

2. The optical lens assembly of claim 1 , wherein the image-side surface of the third lens element is convex.

3. The optical lens assembly of claim 1 , wherein a curvature radius of the object-side surface of the first lens element is R 1 , and the focal length of the optical lens assembly is f, and the following condition is satisfied:
0< R 1/ f< 0.40.

4. The optical lens assembly of claim 3 , wherein the object-side surface of the first lens element has the largest curvature of all surfaces of lens elements in the optical lens assembly, and the image-side surface of the first lens element and the object-side surface of the second lens element have the smallest curvature of all surfaces of lens elements in the optical lens assembly.

5. The optical lens assembly of claim 1 , wherein the focal length of the optical lens assembly is f, the curvature radius of the image-side surface of the second lens element is R 4 , and the following condition is satisfied:
1.65< f/R 4<6.0.

6. The optical lens assembly of claim 1 , wherein the first lens element, the second lens element, and third lens element are non-cemented lens elements, an axial distance between the first lens element and the second lens element is T 12 , an axial distance between the second lens element and the third lens element is T 23 , and the following condition is satisfied:
0< T 12/ T 23<1.0.

7. The optical lens assembly of claim 6 , wherein the axial distance between the first lens element and the second lens element is T 12 , the axial lens element between the second lens element and the third lens element is T 23 , and the following condition is satisfied:
0< T 12/ T 23<0.50.

8. The optical lens assembly of claim 1 , wherein the focal length of the optical lens assembly is f, a maximum image height of the optical lens assembly is ImgH, and the following condition is satisfied:
2.3< f /Img H <4.5.

9. The optical lens assembly of claim 1 , wherein the focal length of the optical lens assembly is f, a focal length of the first lens element is f1, a focal length of the second lens element is f2, and the following condition is satisfied:
3.65<| f/f 1|+| f/f 2|<6.0.

10. The optical lens assembly of claim 1 , wherein a curvature of the image-side surface of the second lens element is increasingly concave from a paraxial region to an off-axis region thereof.

11. An image capturing device, comprising:
the optical lens assembly of claim 1 ; and
an image sensor.

12. An image capturing device, comprising:
the optical lens assembly of claim 1 ;
a prism; and
an image sensor.

13. An optical lens assembly comprising, in order from an object side to an image side:
a first lens element with positive refractive power having an object-side surface being convex, wherein the object-side surface and an image-side surface of the first lens element are aspheric;
a second lens element with negative refractive power having an image-side surface being concave, wherein an object-side surface and the image-side surface of the second lens element are aspheric; and
a third lens element with negative refractive power having an object-side surface being concave, wherein the object-side surface and an image-side surface of the third lens element are aspheric;
wherein the optical lens assembly has a total of three lens elements, the first lens element, the second lens element, and the third lens element are non-cemented lens elements, a focal length of the optical lens element is f, a curvature radius of the image-side surface of the second lens element is R 4 , a curvature radius of the object-side surface of the third lens element is R 5 , an Abbe number of the first lens element is V1, an Abbe number of the second lens element is V2, an Abbe number of the third lens element is V3, and the following conditions are satisfied:
1.25< f/R 4;
−2.6< R 5/ f< 0;and

( V 2+ V 3)/ V 1≤0.89.

14. The optical lens assembly of claim 13 , wherein the optical lens assembly further comprises an aperture stop with no lens element disposed between the aperture stop and the first lens element, and the image-side surface of the third lens element is convex.

15. The optical lens assembly of claim 13 , wherein an axial distance between the first lens element and the second lens element is T 12 , a central thickness of the second lens element is CT 2 , and the following condition is satisfied:
0 <T 12/CT2<0.80.

16. The optical lens assembly of claim 15 , wherein a curvature radius of the image-side surface of the first lens element is R 2 , a curvature radius of the object-side surface of the second lens element is R 3 , and the following condition is satisfied:
0.5<|( R 2+ R 3)/( R 2− R 3)|<20.

17. The optical lens assembly of claim 13 , wherein a half of a maximal field of view of the optical lens assembly is HFOV, and the following condition is satisfied:
7.5 degrees< H FOV<23.5 degrees.

18. The optical lens assembly of claim 13 , wherein a central thickness of the first lens element is CT 1 , a central thickness of the second lens element is CT 2 , and the following condition is satisfied:
0<CT1/CT2<1.65.

19. The optical lens assembly of claim 18 , wherein the central thickness of the first lens element is CT 1 , the central thickness of the second lens element is CT 2 , and the following condition is satisfied:
0<CT1/CT2<1.00.

20. The optical lens assembly of claim 13 , wherein an axial distance between the object-side surface of the first lens element and the image-side surface of the third lens element is TD, and the focal length of the optical lens assembly is f, and the following condition is satisfied:
0.50< TD/f< 0.90.

21. The optical lens assembly of claim 13 , wherein a curvature of the object-side surface of the third lens element is increasingly concave from a paraxial region to an off-axis region thereof.

22. An optical lens assembly comprisi

Assignees

• Largan Precision Co Ltd

Inventors

• Hsueh Chun-Che
• Huang Hsin-Hsuan

Classifications

• G02B13/0035 Primary

  having three lenses · CPC title