Image pickup lens

Patent metadata

Field	Value
Publication number	US-9638898-B2
Application number	US-201514796536-A
Country	US
Kind code	B2
Filing date	Jul 10, 2015
Priority date	Mar 29, 2012
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

An image pickup lens includes a first lens having a positive refractive power, a second meniscus lens having a negative refractive power, a third lens, a fourth meniscus lens having a negative refractive power, and a fifth lens having both sides formed as aspheric surfaces with a positive refractive power, wherein an F-value is 2.41 or smaller.

First claim

What is claimed is:

1. An image pickup lens for use with a solid imaging element, the image pickup lens comprising, in order from an object side to an image side:
a first lens having a positive refractive power,
a second lens having a meniscus shape and a negative refractive power,
a third lens having a positive refractive power,
a fourth lens having a meniscus shape, a negative refractive power and a concave surface facing the image side near an optical axis, and
a fifth lens having both sides formed as aspheric surfaces and a positive refractive power; wherein
an F-value of the image pickup lens is 2.41 or smaller, and satisfies an expression (8):
−5.0< f 4/ f<− 1.75   (8)

where f represents a focal length of the overall optical system of the image pickup lens, and f4 represents a focal length of the fourth lens.

2. The image pickup lens according to claim 1 , wherein
the first lens has a convex surface facing the object side,
the second lens has a concave surface facing the image side, and
the third lens has a convex surface facing the object side near an optical axis.

3. The image pickup lens according to claim 1 , wherein
the fourth lens has both sides formed as aspheric surfaces having a pole-change point other than on the optical axis on the object side surface and the image side surface thereof, and
the fifth lens has a meniscus shape and a concave surface facing the image side near the optical axis, having a pole-change point other than on the optical axis on the object side surface and the image side surface thereof.

4. The image pickup lens according to claim 1 , wherein the first lens and the second lens satisfy expressions (1), (2) and (3):
45<ν1<90  (1)

22<ν2<35  (2)

2.0<ν1/ν2<2.6  (3)

where ν1 represents an Abbe number of the first lens, and ν2 represents an Abbe number of the second lens.

5. The image pickup lens according to claim 1 , wherein the image pickup lens satisfy expressions (4) and (5):
0.7< f 1/ f< 0.9  (4)

−1.3< f 2/ f<− 0.9  (5)

where f represents a focal length of the overall optical system of the image pickup lens, f1 represents a focal length of the first lens, and f2 represents a focal length of the second lens.

6. The image pickup lens according to claim 1 , wherein the image pickup lens satisfy expression (6):
1.1< TTL/f< 1.3  (6)

where TTL represents a distance on an optical axis from the object side surface of the first lens to the imaging surface with a filter removed, and f represents a focal length of the overall optical system of the image pickup lens.

7. The image pickup lens according to claim 1 , wherein the image pickup lens satisfy expression (9):
1.5< f 5/ f< 4.0  (9)

f represents a focal length of the overall optical system of the image pickup lens, and f5 represents a focal length of the fifth lens.

8. An image pickup lens for use with a solid imaging element, the image pickup lens comprising, in order from an object side to an image side:
an aperture stop,
a first lens having a positive refractive power,
a second lens having a meniscus shape, a concave surface facing the image side near the optical axis, and a negative refractive power,
a third lens having a convex surface facing the object side near an optical axis and a positive refractive power,
a fourth lens having a negative refractive power, and
a fifth lens having both sides formed as aspheric surfaces, a meniscus shape and a concave surface facing the image side near the optical axis, and a positive refractive power, wherein
the image pickup lens satisfy expression (9):
1.5< f 5/ f< 4.0  (9)

where f represents a focal length of the overall optical system of the image pickup lens, and f5 represents a focal length of the fifth lens.

9. The image pickup lens according to claim 8 , wherein
the first lens has a convex surface facing the object side.

10. The image pickup lens according to claim 8 , wherein
the fourth lens has a concave surface facing the image side near the optical axis, having both sides formed as aspheric surfaces having a pole-change point other than on the optical axis on the object side surface and the image side surface thereof, and
the fifth lens has a pole-change point other than on the optical axis on the object side surface and the image side surface thereof.

11. The image pickup lens according to claim 8 , wherein the first lens and the second lens satisfy expressions (1), (2) and (3):
45<ν1<90  (1)

22<ν2<35  (2)

2.0<ν1/ν2<2.6  (3)

where ν1 represents an Abbe number of the first lens, and ν2 represents an Abbe number of the second lens.

12. The image pickup lens according to claim 8 , wherein the image pickup lens satisfy expressions (4) and (5):
0.7< f 1/ f< 0.9  (4)

−1.3< f 2/ f 21 −0.9  (5)

where f represents a focal length of the overall optical system of the image pickup lens, f1 represents a focal length of the first lens, and f2 represents a focal length of the second lens.

13. The image pickup lens according to claim 8 , wherein the image pickup lens satisfy expression (6):
1.1< TTL/f< 1.3  (6)

where TTL represents a distance on the optical axis from the object side surface of the first lens to the imaging surface with a filter removed, and f represents a focal length of the overall optical system of the image pickup lens.

14. The image pickup lens according to claim 8 , wherein the image pickup lens satisfy expression. (8):
−5.0< f 4 /f<− 1.75  (8)

where f4 represents a focal length of the fourth lens, and f represents a focal length of the overall optical system of the image pickup lens.

15. An image pickup lens for use with a solid imaging element, the image pickup lens comprising, in order from an object side to an image side:
an aperture stop,
a first lens having a positive refractive power,
a second lens having a meniscus shape and a concave surface facing the image side near the optical axis, and a negative refractive power,
a third lens having a convex surface facing the object side near an optical axis and a positive refractive power,
a fourth lens having a concave surface facing the image side near the optical axis and a negative refractive power, and
a fifth lens having both sides formed as aspheric surfaces and having positive refractive power, wherein
the image pickup lens satisfy expression (5):
−1.3< f 2/ f<− 0.9  (5)

where f represents a focal length of the overall optical system of the image pickup lens, and f2 represents a focal length of the second lens.

16. The image pickup lens according to claim 15 , wherein
the first lens has a convex surface facing the object side.

17. The image pickup lens according to claim 15 , wherein
the fourth lens has both sides formed as aspheric surfaces having a pole-change point other than on the optical axis on the object side surface and the image side surface thereof, and
the fifth lens has a meniscus shape and a concave surface facing the image side near the optical axis, having a pole-change point other than on the optical axis on the object side surface and the image side surface thereof.

18. The image pickup lens according to claim 15 , wherein the first lens and the second lens satisfy expressions (1), (2) and (3):
45<ν1<90  (1)

22<ν2<35  (2)

2.0<ν1/ν2<2.6  (3)

where ν1 represents an Abbe number of the first lens, and ν2 represents an Abbe number of the second lens.

19. The image pickup lens according to claim 15 , wherein the image pickup lens satisfy expression (4)

Assignees

• Kantatsu Co Ltd

Inventors

• Hashimoto Masaya

Classifications

• G02B9/60

  having five components only · CPC title

• G02B13/0045 Primary

  having five or more lenses · CPC title