# US 11,442,253 B2 · Imaging lens and imaging apparatus

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- Number: US 11,442,253 B2
- Document ID: US11442253B2
- Status: Granted
- Kind: B2
- Application number: 16/784,079
- Filed: 2020-02-06
- Published: 2020-06-04
- Granted: 2022-09-13
- Earliest claimed: 2017-03-01
- Assignees: FUJIFILM Corporation
- Applicants: FUJIFILM Corporation
- Inventors: Taiga Noda
- Web page: https://patentgrep.com/patent/US11442253B2

## CPC

- G02B 13/0045: {having five or more lenses}
- G02B 7/04: with mechanism for focusing or varying magnification
- G02B 9/64: having more than six components
- G02B 15/22: with movable lens means specially adapted for focusing at close distances
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

The imaging lens consists of, in order from an object side, a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a negative refractive power, and is configured such that, during focusing, the first lens group and the third lens group remain stationary with respect to an image plane, the second lens group moves in the direction of an optical axis, the first lens group includes a first-a negative lens and a first-b negative lens successively in order from a position closest to the object side, and that the second lens group includes an aperture stop that moves integrally with the second lens group during focusing.

## Claims

### Claim 1

An imaging lens comprising, in order from an object side:
a first lens group having a negative refractive power;
a second lens group having a positive refractive power; and
a third lens group having a negative refractive power,
wherein during focusing, the first lens group and the third lens group remain stationary with respect to an image plane, and the second lens group moves in a direction of an optical axis, and
the first lens group includes a first-a negative lens and a first-b negative lens successively in order from a position closest to the object side.

### Claim 2 (depends on 1)

The imaging lens according to claim 1,
wherein a surface of the second lens group closest to the object side has a shape convex toward the object side.

### Claim 3 (depends on 1)

The imaging lens according to claim 1,
wherein in a case where an Abbe number of the first-b negative lens in a d line is set to νd1b, and an Abbe number of the first-a negative lens in the d line is set to νd1a, the following Conditional Expression (1) is satisfied.
20<νd1b−νd1a<56 (1)

### Claim 4 (depends on 1)

The imaging lens according to claim 1,
wherein the first lens group includes a positive lens at a position closest to an image side.

### Claim 5 (depends on 4)

The imaging lens according to claim 4,
wherein in a case where an Abbe number of the first-b negative lens in a d line is set to νd1b, and an Abbe number of the positive lens of the first lens group closest to an image side in the d line is set to νd1gp, the following Conditional Expression (2) is satisfied.
20<νd1b−νd1gp<58 (2)

### Claim 6 (depends on 1)

The imaging lens according to claim 1,
wherein in a case where a curvature radius of a surface of the second lens group closest to the object side is set to R2g1, and a focal length of the first lens group is set to f1, the following Conditional Expression (3) is satisfied.
−1.2<R2g1/f1<−0.1 (3)

### Claim 7 (depends on 1)

The imaging lens according to claim 1,
wherein the second lens group includes a positive lens at a position closest to the object side.

### Claim 8 (depends on 1)

The imaging lens according to claim 1,
wherein the second lens group includes a positive lens, a positive lens, and a negative lens successively in order from a position closest to the object side.

### Claim 9 (depends on 1)

The imaging lens according to claim 1,
wherein in a case where a focal length of the first-a negative lens is set to f1a, and a focal length of the first lens group is set to f1, the following Conditional Expression (5) is satisfied.
0.3<f1a/f1<1.1 (5)

### Claim 10 (depends on 1)

The imaging lens according to claim 1,
wherein in a case where a focal length of the first-b negative lens is set to f1b, and a focal length of the first lens group is set to f1, the following Conditional Expression (6) is satisfied.
0.6<f1b/f1<2.2 (6)

### Claim 11 (depends on 1)

The imaging lens according to claim 1,
wherein the third lens group consists of a positive lens and a negative lens in order from the object side.

### Claim 12 (depends on 3)

The imaging lens according to claim 3,
wherein the following Conditional Expression (1-1) is satisfied.
24<νd1b−νd1a<53 (1-1)

### Claim 13 (depends on 5)

The imaging lens according to claim 5,
wherein the following Conditional Expression (2-1) is satisfied.
24<νd1b−νd1gp<55 (2-1)

### Claim 14 (depends on 6)

The imaging lens according to claim 6,
wherein the following Conditional Expression (3-1) is satisfied.
−0.9<R2g1/f1<−0.2 (3-1)

### Claim 15 (depends on 9)

The imaging lens according to claim 9,
wherein the following Conditional Expression (5-1) is satisfied.
0.4<f1a/f1<0.9 (5-1)

### Claim 16 (depends on 10)

The imaging lens according to claim 10,
wherein the following Conditional Expression (6-1) is satisfied.
0.9<f1b/f1<1.9 (6-1)

### Claim 17 (depends on 1)

An imaging apparatus comprising the imaging lens according to claim 1.