Image capturing system

Patent metadata

Field	Value
Publication number	US-RE46747-E
Application number	US-201514816057-A
Country	US
Kind code	E1
Filing date	Aug 2, 2015
Priority date	Jan 12, 2012
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

An image capturing system 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 and a fifth lens element. The first lens element with positive refractive power has a convex object-side surface. The second lens element has negative refractive power. The third lens element has positive refractive power. The fourth lens element with negative refractive power has a concave object-side surface and a convex image-side surface, wherein at least one of the object-side surface and the image-side surface of the fourth lens element is aspheric. The fifth lens element with refractive power has a concave image-side surface, wherein at least one of an object-side surface and the image-side surface of the fifth lens element is aspheric, and the fifth lens element has at least one inflection point on the image-side surface thereof.

First claim

What is claimed is:

1. An image capturing system 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;
a second lens element with negative refractive power;
a third lens element with positive refractive power;
a fourth lens element with negative refractive power having a concave object-side surface and a convex image-side surface, wherein at least one of the object-side surface and the image-side surface of the fourth lens element is aspheric; and
a fifth lens element with refractive power having a concave image-side surface, wherein at least one of an object-side surface and the image-side surface of the fifth lens element is aspheric, and the fifth lens element has at least one inflection point on the image-side surface thereof;
wherein the first through fifth lens elements are five independent and non-cemented lens elements, a maximum image height of the image capturing system is ImgH, an axial distance between the object-side surface of the first lens element and an image plane is TTL, a focal length of the image capturing system is f, and the following relationship is satisfied:
2.8 mm<(f/ImgH)×TTL<4.6 mm.

2. The image capturing system of claim 1 , wherein the focal length of the image capturing system is f, a focal length of the second lens element is f2, and the following relationship is satisfied:
−1.4<f/f2<−0.18.

3. The image capturing system of claim 1 , wherein a central thickness of the second lens element is CT2, a central thickness of the third lens element is CT3, a central thickness of the fourth lens element is CT4, and the following relationship is satisfied:
0.20 mm<(CT2+CT3+CT4)/3<0.31 mm.

4. The image capturing system of claim 1 , wherein an Abbe number of the first lens element is V1, an Abbe number of the second lens element is V2, and the following relationship is satisfied:
20<V1−V2<50.

5. The image capturing system of claim 1 , wherein an Abbe number of the third lens element is V3, an Abbe number of the fourth lens element is V4, and the following relationship is satisfied:
27<V3−V4<45.

6. The image capturing system of claim 1 , wherein the axial distance between the object-side surface of the first lens element and an image plane is TTL, the focal length of the image capturing system is f, a half of the maximal field of view of the image capturing system is HFOV, and the following relationship is satisfied:
6.5 mm 2 <TTL×f/tan(HFOV)<13.4 mm 2 .

7. The image capturing system of claim 1 , wherein at least one of the object-side surface and the image-side surface of the first through third lens elements respectively is aspheric, and the first through fifth lens elements are made of plastic material.

8. The image capturing system of claim 7 , wherein a maximal field of view of the image capturing system is FOV, and the following relationship is satisfied:
70 degrees<FOV<90 degrees.

9. The image capturing system of claim 7 , wherein the second lens element has a concave image-side surface.

10. The image capturing system of claim 7 , wherein the fifth lens element has a convex object-side surface.

11. The image capturing system of claim 1 , wherein the focal length of the image capturing system is f, and the following relationship is satisfied:
1.8 mm<f<3.2 mm.

12. An image capturing system 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;
a second lens element with negative refractive power;
a third lens element with refractive power;
a fourth lens element with negative refractive power having a concave object-side surface and a convex image-side surface, wherein at least one of the object-side surface and the image-side surface of the fourth lens element is aspheric; and
a fifth lens element with refractive power having a concave image-side surface, wherein at least one of an object-side surface and the image-side surface of the fifth lens element is aspheric, and the fifth lens element has at least one inflection point on the image-side surface thereof;
wherein an axial distance between the object-side surface of the first lens element and an image plane is TTL, a focal length of the image capturing system is f, a half of the maximal field of view of the image capturing system is HFOV, an Abbe number of the third lens element is V3, an Abbe number of the fourth lens element is V4, and the following relationships are satisfied:
6.0 mm 2 <TTL×f/tan(HFOV)<16.0 mm 2 ; and

27<V3−V4<45.

13. The image capturing system of claim 12 , wherein the second lens element has a concave image-side surface.

14. The image capturing system of claim 12 , wherein a central thickness of the second lens element is CT2, a central thickness of the third lens element is CT3, a central thickness of the fourth lens element is CT4, and the following relationship is satisfied:
0.2 mm<(CT2+CT3+CT4)/3<0.31 mm.

15. The image capturing system of claim 12 , wherein an Abbe number of the first lens element is V1, an Abbe number of the second lens element is V2, and the following relationship is satisfied:
20<V1−V2<50.

16. The image capturing system of claim 12 , wherein the axial distance between the object-side surface of the first lens element and the image plane is TTL, the focal length of the image capturing system is f, the half of the maximal field of view of the image capturing system is HFOV, and the following relationship is satisfied:
6.5 mm 2 <TTL×f/tan(HFOV)<13.4 mm 2 .

17. The image capturing system of claim 12 , wherein a maximal field of view of the image capturing system is FOV, and the following relationship is satisfied:
70 degrees<FOV<90 degrees.

18. The image capturing system of claim 12 , wherein the focal length of the image capturing system is f, and the following relationship is satisfied:
1.8 mm<f<3.2 mm.

19. The image capturing system of claim 12 , wherein at least one of the object-side surface and the image-side surface of the first through third lens elements respectively is aspheric, and the first through fifth lens elements are made of plastic material.

20. The image capturing system of claim 12 , wherein a maximum image height of the image capturing system is ImgH, the axial distance between the object-side surface of the first lens element and the image plane is TTL, and the following relationship is satisfied:
TTL/ImgH<1.55.

21. An image capturing system 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;
a second lens element with negative refractive power;
a third lens element with refractive power;
a fourth lens element with negative refractive power having a concave object-side surface and a convex image-side surface, wherein at least one of the object-side surface and the image-side surface of the fourth lens element is aspheric; and
a fifth lens element with refractive power having a concave image-side surface, wherein at least one of an object-side surface and the image-side surface of the fifth lens element is aspheric, and the fifth lens element has at least one inflection point on the image-side surface thereof;
wherein the first through fifth lens elements are five independent and non-cemented lens elements, an axial distance between the object-side surface of the first lens element and

Assignees

• Largan Precision Co Ltd

Inventors

• Hsu Po Lun
• Tsai Tsung Han
• Chou Ming Ta

Classifications

• G02B13/0045 Primary

  having five or more lenses · CPC title

• G02B9/60

  having five components only · 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