# US 11,906,705 B2 · Optical system

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 11,906,705 B2
- Document ID: US11906705B2
- Status: Granted
- Kind: B2
- Application number: 17/202,470
- Filed: 2021-03-16
- Published: 2021-07-01
- Granted: 2024-02-20
- Earliest claimed: 2014-07-22
- Assignees: Samsung Electro-Mechanics Co., Ltd.
- Applicants: Samsung Electro-Mechanics Co., Ltd.
- Inventors: Jin Hwa Jung
- Web page: https://patentgrep.com/patent/US11906705B2

## CPC

- G02B 13/0045: {having five or more lenses}
- G02B 9/64: having more than six components
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

There is provided an optical system including: a first lens having positive refractive power and having a convex object-side surface; a second lens having positive refractive power; a third lens having refractive power; a fourth lens having refractive power; a fifth lens having refractive power; a sixth lens having refractive power; and a seventh lens having negative refractive power and having a concave image-side surface, wherein the first to seventh lenses are sequentially disposed from an object side, whereby an aberration improvement effect may be increased and a high degree of resolution may be realized.

## Claims

### Claim 1

An optical system comprising:
a first lens having positive refractive power and comprising a convex object-side surface and a concave image-side surface;
a second lens having refractive power;
a third lens having refractive power and comprising a concave image-side surface;
a fourth lens having positive refractive power;
a fifth lens having negative refractive power;
a sixth lens having positive refractive power; and
a seventh lens having negative refractive power,
wherein the first to seventh lenses are sequentially disposed from an object side, and
wherein |(r7−r8)/(r7+r8)|<1.4 is satisfied, where r7 is a radius of curvature of an object-side surface of the fourth lens, and r8 is a radius of curvature of an image-side surface of the fourth lens.

### Claim 2 (depends on 1)

The optical system of claim 1, wherein the second lens has a convex object-side surface.

### Claim 3 (depends on 1)

The optical system of claim 1, wherein the third lens has negative refractive power.

### Claim 4 (depends on 1)

The optical system of claim 1, wherein the fourth lens has a convex object-side surface.

### Claim 5 (depends on 4)

The optical system of claim 4, wherein the fourth lens has a convex image-side surface.

### Claim 6 (depends on 1)

The optical system of claim 1, wherein the sixth lens has a convex image-side surface.

### Claim 7 (depends on 1)

The optical system of claim 1, wherein the seventh lens has a concave object-side surface.

### Claim 8 (depends on 7)

The optical system of claim 7, wherein the seventh lens has a concave image-side surface.

### Claim 9 (depends on 1)

The optical system of claim 1, further comprising an image sensor converting an image of a subject incident thereon through the first to seventh lenses into an electrical signal,
wherein IMH/EPD<2.0 is satisfied, where IMH is a diagonal length of the image sensor, and EPD is an entrance pupil diameter of the optical system.

### Claim 10 (depends on 1)

The optical system of claim 1, wherein BFL/TTL<0.25 is satisfied, where BFL is a distance from an image-side surface of the seventh lens to an imaging surface, and TTL is a distance from an object-side surface of the first lens to the imaging surface.

### Claim 11 (depends on 1)

The optical system of claim 1, wherein TTL/F<1.2 is satisfied, where TTL is a distance from an object-side surface of the first lens to an imaging surface, and F is an overall focal length of the optical system.

### Claim 12 (depends on 1)

The optical system of claim 1, wherein |Nd4−Nd6|<0.1 is satisfied, where Nd4 is a refractive index of the fourth lens, and Nd6 is a refractive index of the sixth lens.

### Claim 13 (depends on 1)

The optical system of claim 1, wherein r14/F>0.3 is satisfied, where r14 is a radius of curvature of an image-side surface of the seventh lens, and F is an overall focal length of the optical system.

### Claim 14 (depends on 1)

The optical system of claim 1, wherein F12/F>0.5 is satisfied, where F12 is a composite focal length of the first and second lenses, and F is an overall focal length of the optical system.