Imaging lens

Patent metadata

Field	Value
Publication number	US-12259526-B2
Application number	US-202117453599-A
Country	US
Kind code	B2
Filing date	Nov 4, 2021
Priority date	Nov 4, 2020
Publication date	Mar 25, 2025
Grant date	Mar 25, 2025

Abstract

There is provided an imaging lens having a low profile and a low F-number and allowing satisfactory correction of aberrations. An imaging lens comprises in order from an object side, a first lens L 1 with positive refractive power, a second lens L 2 with negative refractive power, a third lens L 3 , a fourth lens L 4 with positive refractive power, and a fifth lens L 5 with negative refractive power, wherein an image-side surface of said fourth lens L 4 is convex in a paraxial region, an object-side surface of said fifth lens L 5 is an aspheric surface having at least one inflection point, and the following conditional expressions are satisfied:

f /Dep<2.0  (1)

1.2< T 3/ T 2<1.8  (2)

15< vd 3<35  (3)

−1.0< R 5 f/R 5 r <−0.3  (4)
where f: a focal length of the overall optical system of the imaging lens, Dep: an entrance pupil diameter of the imaging lens, T2: a thickness along the optical axis X of the second lens L 2, T3: a thickness along the optical axis X of the third lens L 3, vd3: an abbe number at d-ray of the third lens L 3, R5f: a curvature radius of an object-side surface of the fifth lens L 5 , and R5r: a curvature radius of an image-side surface of the fifth lens L 5.

First claim

What is claimed is:

1. An imaging lens for forming an image of an object on an image sensor comprising, in order from an object side to an image side,
a first lens with positive refractive power,
a second lens with negative refractive power,
a third lens,
a fourth lens with positive refractive power, and
a fifth lens with negative refractive power,
wherein an image-side surface of said fourth lens is convex in a paraxial region, an object-side surface of said fifth lens is an aspheric surface having at least one inflection point, and the following conditional expressions (1) to (4) and (10′) are satisfied:
f /Dep<2.0  (1)

1.2< T 3/ T 2<1.8  (2)

15< vd 3<35  (3)

−1.0< R 5 f/R 5 r<− 0.3  (4)

0.318<= D 12/ D 23<0.6  (10′)

where
f: a focal length of an overall optical system of the imaging lens,
Dep: an entrance pupil diameter of the imaging lens,
T2: a thickness along an optical axis X of the second lens L 2 ,
T3: a thickness along an optical axis X of the third lens L 3 ,
vd3: an abbe number at d-ray of the third lens L 3 ,
R5f: a curvature radius of an object-side surface of the fifth lens L 5 ,
R5r: a curvature radius of an image-side surface of the fifth lens L 5 ,
D12: a distance along the optical axis between the first lens and the second lens, and
D23: a distance along the optical axis between the second lens and the third lens.

2. The imaging lens according to claim 1 , wherein the following conditional expression (5) is satisfied:
5.0<| f 3|/ f< 95.0  (5)

where
f3: a focal length of the third lens.

3. The imaging lens according to claim 1 , wherein the following conditional expression (6) is satisfied:
−5.0< f 23/ f<− 1.5  (6)

where
f23: a composite focal length of the second lens and the third lens.

4. The imaging lens according to claim 1 , wherein the following conditional expression (7) is satisfied:
0.2< f 34/ f< 1.0  (7)

where
f34: a composite focal length of the third lens and the fourth lens.

5. The imaging lens according to claim 1 , wherein the following conditional expression (8) is satisfied:
0.02<| R 2 r/R 3 f|< 1.0  (8)

where
R2r: a curvature radius of an image-side surface of the second lens, and
R3f: a curvature radius of an object-side surface of the third lens.

6. The imaging lens according to claim 1 , wherein the following conditional expression (9) is satisfied:
0.01< D 12/ f< 0.08  (9)

where
D12: a distance along the optical axis between the first lens and the second lens.

Assignees

• Tokyo Visionary Optics Co Ltd

Inventors

• Tokuno Koki
• Yang Ruidong

Classifications

• G02B9/60

  having five components only · CPC title

• G03B30/00

  Camera modules comprising integrated lens units and imaging units, specially adapted for being embedded in other devices, e.g. mobile phones or vehicles · CPC title

• G02B13/06

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

• G02B13/0045 Primary

  having five or more lenses · CPC title