Optical lens assembly comprising seven lenses of −++−−+− or +++−−+− refractive powers, image capturing unit and electronic device

Patent metadata

Field	Value
Publication number	US-12085696-B2
Application number	US-202318206572-A
Country	US
Kind code	B2
Filing date	Jun 6, 2023
Priority date	Apr 24, 2019
Publication date	Sep 10, 2024
Grant date	Sep 10, 2024

Abstract

An optical lens assembly includes seven lens elements which are, in order from object side to image side: first lens element, second lens element, third lens element, fourth lens element, fifth lens element, sixth lens element and seventh lens element. The first lens element has object-side surface having at least one convex shape in off-axis region thereof. The second lens element with positive refractive power has object-side surface being convex in paraxial region thereof. The third lens element has image-side surface being convex in paraxial region thereof. The sixth lens element with positive refractive power has object-side surface being convex in paraxial region thereof. The seventh lens element has image-side surface being concave in paraxial region thereof, and the image-side surface of the seventh lens element has at least one convex critical point in off-axis region thereof. The optical lens assembly has a total of seven lens elements.

First claim

What is claimed is:

1. An optical lens assembly comprising seven lens elements, the seven lens elements being, in order from an object side to an image side, a first lens element, a second lens element, a third lens element, a fourth lens element, a fifth lens element, a sixth lens element and a seventh lens element;
wherein the first lens element with negative refractive power has an object-side surface being concave in a paraxial region thereof, the third lens element has positive refractive power, the sixth lens element has an image-side surface having at least one inflection point in an off-axis region thereof, a curvature radius of an object-side surface of the sixth lens element has a same sign as a curvature radius of the image-side surface of the sixth lens element, a central thickness of the second lens element is larger than a central thickness of the sixth lens element, and a total number of lens elements of the optical lens assembly is seven;
wherein the curvature radius of the object-side surface of the sixth lens element is R11, the curvature radius of the image-side surface of the sixth lens element is R12, and the following condition is satisfied:
( R 11+ R 12)/( R 11− R 12)<0.50;

wherein 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, an Abbe number of the fourth lens element is V4, an Abbe number of the fifth lens element is V5, an Abbe number of the sixth lens element is V6, an Abbe number of the seventh lens element is V7, an Abbe number of the i-th lens element is Vi, a refractive index of the first lens element is N1, a refractive index of the second lens element is N2, a refractive index of the third lens element is N3, a refractive index of the fourth lens element is N4, a refractive index of the fifth lens element is N5, a refractive index of the sixth lens element is N6, a refractive index of the seventh lens element is N7, a refractive index of the i-th lens element is Ni, and at least one lens element of the optical lens assembly satisfies the following condition:
8.0< Vi/Ni< 11.8, wherein i= 1,2,3,4,5,6 or 7.

2. The optical lens assembly of claim 1 , wherein a focal length of the optical lens assembly is f, a curvature radius of an image-side surface of the first lens element is R2, and the following condition is satisfied:
f/R 2<0.60.

3. The optical lens assembly of claim 1 , wherein an axial distance between the object-side surface of the first lens element and an image surface is TL, a maximum image height of the optical lens assembly is ImgH, a maximum field of view of the optical lens assembly is FOV, a maximum effective radius of the object-side surface of the first lens element is Y11, a maximum effective radius of an image-side surface of the seventh lens element is Y72, and the following conditions are satisfied:
0.80<( TL /ImgH)+cot(FOV)<1.25; and
Y 11/ Y 72<1.0.

4. The optical lens assembly of claim 1 , wherein the central thickness of the second lens element is larger than a central thickness of the third lens element.

5. The optical lens assembly of claim 1 , wherein the fifth lens element has an image-side surface being concave in a paraxial region thereof, and the image-side surface of the fifth lens element has at least one inflection point in an off-axis region thereof.

6. The optical lens assembly of claim 1 , wherein the central thickness of the second lens element is larger than a central thickness of the first lens element.

7. The optical lens assembly of claim 1 , wherein the fifth lens element has an object-side surface being concave in a paraxial region thereof.

8. The optical lens assembly of claim 1 , wherein a curvature radius of an image-side surface of the second lens element has a different sign from a curvature radius of an image-side surface of the third lens element.

9. The optical lens assembly of claim 1 , wherein the object-side surface of the first lens element is concave in a paraxial region thereof and has at least one convex critical point in an off-axis region thereof, a vertical distance between a critical point on the object-side surface of the first lens element and an optical axis is Yc11, a focal length of the optical lens assembly is f, and the following condition is satisfied:
0.20< Yc 11/ f< 0.60.

10. The optical lens assembly of claim 1 , wherein an axial distance between the third lens element and the fourth lens element is T34, an axial distance between the sixth lens element and the seventh lens element is T67, and the following condition is satisfied:
1.0< T 67/ T 34.

11. An image capturing unit, comprising:
the optical lens assembly of claim 1 ; and
an image sensor disposed on an image surface of the optical lens assembly.

12. An electronic device, comprising:
the image capturing unit of claim 11 .

13. The optical lens assembly of claim 1 ,
wherein the second lens element has an image-side surface being concave in a paraxial region thereof, the fifth lens element has negative refractive power, each of an object-side surface and an image-side surface of the seventh lens element has at least one inflection point in an off-axis region thereof, and a focal length of the fourth lens element has a same sign as a focal length of the seventh lens element.

14. The optical lens assembly of claim 13 , wherein a central thickness of the seventh lens element is larger than a central thickness of the first lens element.

15. The optical lens assembly of claim 13 , wherein an axial distance between the object-side surface of the first lens element and an image surface is TL, a maximum image height of the optical lens assembly is ImgH, a maximum field of view of the optical lens assembly is FOV, and the following condition is satisfied:
0.80<( TL /ImgH)+cot(FOV)<1.25.

16. The optical lens assembly of claim 13 , wherein the central thickness of the second lens element is larger than a central thickness of the first lens element.

17. The optical lens assembly of claim 13 , wherein a curvature radius of an image-side surface of the third lens element has a different sign from a curvature radius of the object-side surface of the seventh lens element.

Assignees

• Largan Precision Co Ltd

Inventors

• Tseng Yu-Tai
• Hsueh Chun-Che
• Chen Hung-Shuo
• Chen Wei-Yu

Classifications

• G02B9/64 Primary

  having more than six components · CPC title

• G02B13/0045 Primary

  having five or more lenses · 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

• G02B13/06

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