# US 11,442,250 B2 · Imaging lens

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- Number: US 11,442,250 B2
- Document ID: US11442250B2
- Status: Granted
- Kind: B2
- Application number: 17/004,053
- Filed: 2020-08-27
- Published: 2020-12-17
- Granted: 2022-09-13
- Earliest claimed: 2014-03-20
- Assignees: Tokyo Visionary Optics Co., Ltd.
- Applicants: Tokyo Visionary Optics Co., Ltd.
- Inventors: Yoji Kubota; Kenichi Kubota; Hitoshi Hirano; Tomohiro Yonezawa
- Web page: https://patentgrep.com/patent/US11442250B2

## CPC

- G02B 9/64: having more than six components
- G02B 9/12: having three components only
- G02B 13/0045: {having five or more lenses}
- G02B 27/0025: {for optical correction, e.g. distorsion, aberration}
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

An imaging lens includes a first lens group having positive refractive power; a second lens group; and a third lens group having negative refractive power, arranged in this order from an object side to an image plane side. The first lens group includes a first lens, a second lens, and a third lens. The second lens group includes a fourth lens and a fifth lens. The third lens group includes a sixth lens and a seventh lens having negative refractive power. The first lens is formed in a meniscus shape at a paraxial region thereof. The fourth lens is formed in a meniscus shape at a paraxial region thereof. The seventh lens is formed in a meniscus shape at a paraxial region thereof. The seventh lens has a specific focal length. The second lens is disposed away from the third lens by a specific distance.

## Claims

### Claim 1

An imaging lens comprising:
a first lens group having positive refractive power;
a second lens group; and
a third lens group having negative refractive power, arranged in this order from an object side to an image plane side,
wherein said first lens group includes a first lens, a second lens, and a third lens,
said second lens group includes a fourth lens and a fifth lens,
said third lens group includes a sixth lens and a seventh lens having negative refractive power,
said first lens is formed in a meniscus shape at a paraxial region thereof,
said fourth lens is formed in a meniscus shape at a paraxial region thereof,
said seventh lens is formed in a meniscus shape at a paraxial region thereof, and
said seventh lens has a focal length f7, and said second lens is disposed away from the third lens by a distance D23 on an optical axis thereof so that the following conditional expressions are satisfied:
2.38≤f7/f<0.8,
0.08≤D23/f<0.2,
where f is a focal length of a whole lens system.

### Claim 2 (depends on 1)

The imaging lens according to claim 1, wherein said second lens has a focal length f2 and said third lens has a focal length f3 so that the following conditional expression is satisfied:
0.1<f2/f3<0.6.

### Claim 3 (depends on 1)

The imaging lens according to claim 1, wherein said fourth lens has a focal length f4 so that the following conditional expression is satisfied:
1.0<f4/f<3.0.

### Claim 4 (depends on 1)

The imaging lens according to claim 1, wherein said sixth lens and said seventh lens have a composite focal length f67 so that the following conditional expression is satisfied:
−1.7<f67/f<−0.5.

### Claim 5 (depends on 1)

The imaging lens according to claim 1, wherein said third lens is disposed away from the fourth lens by a distance D34 on an optical axis thereof so that the following conditional expression is satisfied:
0.03<D34/f<0.2.

### Claim 6 (depends on 1)

The imaging lens according to claim 1, wherein said seventh lens has an Abbe's number νd7 so that the following conditional expression is satisfied:
40<νd7<75.

### Claim 7

An imaging lens comprising:
a first lens group;
a second lens group; and
a third lens group having negative refractive power, arranged in this order from an object side to an image plane side,
wherein said first lens group includes a first lens, a second lens, and a third lens having negative refractive power,
said second lens group includes a fourth lens and a fifth lens,
said third lens group includes a sixth lens and a seventh lens,
said first lens is formed in a meniscus shape at a paraxial region thereof,
said fourth lens is formed in a meniscus shape at a paraxial region thereof,
said seventh lens is formed in a meniscus shape at a paraxial region thereof, and
said second lens is disposed away from the third lens by a distance D23 on an optical axis thereof so that the following conditional expression is satisfied:
0.03<D23/f<0.2,
where f is a focal length of a whole lens system.

### Claim 8 (depends on 7)

The imaging lens according to claim 7, wherein said second lens has a focal length f2 and said third lens has a focal length f3 so that the following conditional expression is satisfied:
0.1<f2/f3<0.6.

### Claim 9 (depends on 7)

The imaging lens according to claim 7, wherein said fourth lens has a focal length f4 so that the following conditional expression is satisfied:
1.0<f4/f<3.0,
where f is a focal length of a whole lens system.

### Claim 10 (depends on 7)

The imaging lens according to claim 7, wherein said seventh lens has a focal length f7 so that the following conditional expression is satisfied:
−4.0<f7/f<−0.8,
where f is a focal length of a whole lens system.

### Claim 11 (depends on 7)

The imaging lens according to claim 7, wherein said sixth lens and said seventh lens have a composite focal length f67 so that the following conditional expression is satisfied:
−1.7<f67/f<−0.5,
where f is a focal length of a whole lens system.

### Claim 12 (depends on 7)

The imaging lens according to claim 7, wherein said third lens is disposed away from the fourth lens by a distance D34 on an optical axis thereof so that the following conditional expression is satisfied:
0.03<D34/f<0.2,
where f is a focal length of a whole lens system.

### Claim 13 (depends on 7)

The imaging lens according to claim 7, wherein said seventh lens has an Abbe's number νd7 so that the following conditional expression is satisfied:
40<νd7<75.

### Claim 14

An imaging lens comprising:
a first lens group;
a second lens group; and
a third lens group having negative refractive power, arranged in this order from an object side to an image plane side,
wherein said first lens group includes a first lens, a second lens, and a third lens,
said second lens group includes a fourth lens and a fifth lens,
said third lens group includes a sixth lens having positive refractive power and a seventh lens having negative refractive power,
said fourth lens is formed in a meniscus shape at a paraxial region thereof,
said seventh lens is formed in a meniscus shape at a paraxial region thereof,
said seventh lens has a focal length f7, and
said third lens is disposed away from the fourth lens by a distance D34 on an optical axis thereof so that the following conditional expressions are satisfied:
−2.38≤f7/f<−0.8,
0.03<D34/f<0.2,
where f is a focal length of a whole lens system.

### Claim 15 (depends on 14)

The imaging lens according to claim 14, wherein said second lens has a focal length f2 and said third lens has a focal length f3 so that the following conditional expression is satisfied:
0.1<f2/f3<0.6.

### Claim 16 (depends on 14)

The imaging lens according to claim 14, wherein said fourth lens has a focal length f4 so that the following conditional expression is satisfied:
1.0<f4/f<3.0.

### Claim 17 (depends on 14)

The imaging lens according to claim 14, wherein said sixth lens and said seventh lens have a composite focal length f67 so that the following conditional expression is satisfied:
−1.7<f67/f<−0.5.

### Claim 18 (depends on 14)

The imaging lens according to claim 14, wherein said second lens is disposed away from the third lens by a distance D23 on an optical axis thereof so that the following conditional expression is satisfied:
0.03<D23/f<0.2.