Photographing lens assembly

Patent metadata

Field	Value
Publication number	US-9823446-B2
Application number	US-201615241091-A
Country	US
Kind code	B2
Filing date	Aug 19, 2016
Priority date	Mar 5, 2013
Publication date	Nov 21, 2017
Grant date	Nov 21, 2017

Abstract

A photographing lens assembly includes, 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 and a sixth lens element. The first lens element with positive refractive power has a convex object-side surface. The second lens element, the third lens element and the fourth lens element have refractive power. The fifth lens element with negative refractive power has a convex object-side surface and a concave image-side surface, wherein the surfaces thereof are aspheric, and at least one of the surfaces thereof has at least one inflection point thereon. The sixth lens element with negative refractive power has a convex object-side surface and a concave image-side surface, wherein the surfaces thereof are aspheric, and at least one of the surfaces thereof has at least one inflection point.

First claim

What is claimed is:

1. A photographing lens assembly comprising, in order from an object side to an image side:
a first lens element having positive refractive power;
a second lens element having negative refractive power;
a third lens element having a concave image-side surface;
a fourth lens element having positive refractive power;
a fifth lens element having an object-side surface and an image-side surface being both aspheric; and
a sixth lens element with negative refractive power having a concave image-side surface, wherein an object-side surface and the image-side surface of the sixth lens element are aspheric, and the sixth lens element has at least one inflection point on the image-side surface thereof;
wherein the photographing lens assembly has a total of six lens elements, an axial distance between the fourth lens element and the fifth lens element is T45, an axial distance between the fifth lens element and the sixth lens element is T56, a focal length of the fourth lens element is f4, a focal length of the sixth lens element is f6, and the following relationships are satisfied:
0< T 45/ T 56<0.27; and
−3.0< f 4/ f 6<−0.68.

2. The photographing lens assembly of claim 1 , wherein the fourth lens element has a concave object-side surface and a convex image-side surface.

3. The photographing lens assembly of claim 1 , wherein the second lens element has a concave image-side surface.

4. The photographing lens assembly of claim 1 , wherein the third lens element has positive refractive power.

5. The photographing lens assembly of claim 1 , wherein a focal length of the photographing lens assembly is f, the focal length of the sixth lens element is f6, and the following relationship is satisfied:
−1.5< f/f 6<−0.64.

6. The photographing lens assembly of claim 1 , wherein an axial distance between an object-side surface of the first lens element and the image-side surface of the sixth lens element is TD, a maximum image height of the photographing lens assembly is Y, an axial distance between the image-side surface of the sixth lens element and an image plane is BL, and the following relationship is satisfied:
( TD/Y )+( BL/Y )<1.65.

7. A photographing lens assembly comprising, in order from an object side to an image side:
a first lens element having positive refractive power;
a second lens element having negative refractive power;
a third lens element;
a fourth lens element having positive refractive power;
a fifth lens element having an object-side surface and an image-side surface being both aspheric; and
a sixth lens element with negative refractive power having a concave image-side surface, wherein an object-side surface and the image-side surface of the sixth lens element are aspheric, and the sixth lens element has at least one inflection point on the image-side surface thereof;
wherein the photographing lens assembly has a total of six lens elements, an absolute value of a curvature radius of the object-side surface of the fifth lens element is greater than an absolute value of a curvature radius of the image-side surface of the sixth lens element, an axial distance between the second lens element and the third lens element is T23, an axial distance between the third lens element and the fourth lens element is T34, an axial distance between the fourth lens element and the fifth lens element is T45, an axial distance between the fifth lens element and the sixth lens element is T56, a focal length of the fourth lens element is f4, a focal length of the sixth lens element is f6, and the following relationships are satisfied:
0< T 45/ T 56<0.27;
−3.0< f 4/ f 6<−0.68; and

0.5< T 34/ T 23<1.7.

8. The photographing lens assembly of claim 7 , wherein a focal length of the photographing lens assembly is f, the focal length of the sixth lens element is f6, and the following relationship is satisfied:
−1.5< f/f 6<−0.64.

9. The photographing lens assembly of claim 7 , wherein 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 fifth lens element is V5, and the following relationship is satisfied:
15<( V 2+ V 3+ V 5)/3<40.

10. The photographing lens assembly of claim 7 , wherein an axial distance between an object-side surface of the first lens element and the image-side surface of the sixth lens element is TD, a maximum image height of the photographing lens assembly is Y, an axial distance between the image-side surface of the sixth lens element and an image plane is BL, and the following relationship is satisfied:
( TD/Y )+( BL/Y )<1.65.

11. The photographing lens assembly of claim 7 , wherein an f-number of the photographing lens assembly is Fno, and the following relationship is satisfied:
1.2<Fno<2.3.

12. The photographing lens assembly of claim 7 , wherein the object-side surface of the sixth lens element has a first convex shape at a paraxial region, a second convex shape at an off-axis region, and a concave shape between the first convex shape and the second convex shape.

13. The photographing lens assembly of claim 7 , wherein the object-side surface of the fifth lens element changes from convex at a paraxial region thereof to concave at an off-axis region thereof, and the image-side surface of the fifth lens element changes from concave at a paraxial region thereof to convex at an off-axis region thereof.

14. The photographing lens assembly of claim 7 , wherein a central thickness of the first lens element is greater than a central thickness of the sixth lens element.

15. The photographing lens assembly of claim 7 , wherein an axial distance between the first lens element and the second lens element is smaller than the axial distance between the second lens element and the third lens element.

16. A photographing lens assembly comprising, in order from an object side to an image side:
a first lens element with positive refractive power having a convex object-side surface and a concave image-side surface;
a second lens element having negative refractive power;
a third lens element;
a fourth lens element having positive refractive power;
a fifth lens element having an object-side surface and an image-side surface being both aspheric; and
a sixth lens element with negative refractive power having a concave image-side surface, wherein an object-side surface and the image-side surface of the sixth lens element are aspheric, and the sixth lens element has at least one inflection point on the image-side surface thereof;
wherein the photographing lens assembly has a total of six lens elements, an absolute value of a curvature radius of the image-side surface of the fifth lens element is greater than an absolute value of a curvature radius of the image-side surface of the sixth lens element, an axial distance between the first lens element and the second lens element is smaller than an axial distance between the second lens element and the third lens element, an axial distance between the fourth lens element and the fifth lens element is T45, an axial distance between the fifth lens element and the sixth lens element is T56, and the following relationship is satisfied:
0< T 45/ T 56<0.27.

17. The photographing lens assembly of claim 16 , wherein the fourth lens element has a concave object-side surface and a convex image-side surface.

18. The photographing lens assembly of claim 16 , wherein the third lens element has a convex object-side surface, and each of the first lens element, the second lens element, the thi

Assignees

• Largan Precision Co Ltd

Inventors

• Hsu Po-Lun
• Tsai Tsung-Han
• Huang Hsin-Hsuan

Classifications

• G02B13/18

  with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration {(G02B13/002 takes precedence)} · CPC title

• G02B13/0045 Primary

  having five or more lenses · CPC title

• G02B3/04

  with continuous faces that are rotationally symmetrical but deviate from a true sphere {, e.g. so called "aspheric" lenses} · CPC title

• G02B5/208

  for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation · CPC title

• G02B13/0015

  characterised by the lens design · CPC title