# US 11,307,387 B2 · Optical imaging system including seven lenses of +−++−+−, +−+−++− or +−+−+−− refractive powers

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

- Number: US 11,307,387 B2
- Document ID: US11307387B2
- Status: Granted
- Kind: B2
- Application number: 16/614,095
- Filed: 2018-11-08
- Published: 2021-03-11
- Granted: 2022-04-19
- Earliest claimed: 2018-05-02
- Assignees: Zhejiang Sunny Optical Co., Ltd
- Applicants: Zhejiang Sunny Optical Co., Ltd
- Inventors: Lin Huang
- Web page: https://patentgrep.com/patent/US11307387B2

## CPC

- G02B 13/0045: {having five or more lenses}
- G02B 9/64: having more than six components
- G02B 13/18: with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration {(G02B13/002 takes precedence)}
- G02B 27/0012: {Optical design, e.g. procedures, algorithms, optimisation routines}
- G02B 27/0025: {for optical correction, e.g. distorsion, aberration}
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

## Abstract

An optical imaging system including, sequentially from an object side to an image side along an optical axis, a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens. The first lens and the third lens each has a positive refractive power. The second lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens each has a positive or a negative refractive power. An object-side surface of the first lens is convex, and an image-side surface thereof is concave. An image-side surface of the second lens is concave. An object-side surface of the third lens is convex. An object-side surface of the seventh lens is convex, and an image-side surface thereof is concave. A total effective focal length f of the system and an entrance pupil diameter EPD of the system satisfy: f/EPD≤1.5.

## Claims

### Claim 1

An optical imaging system, comprising: a first lens, a second lens, a third lens, a fourth lens, a fifth lens, a sixth lens and a seventh lens, sequentially from an object side to an image side along an optical axis,
wherein,
the first lens and the third lens each has a positive refractive power;
the second lens, the fourth lens, the fifth lens, the sixth lens, and the seventh lens each has a positive refractive power or a negative refractive power;
an object-side surface of the first lens is a convex surface and an image-side surface of the first lens is a concave surface;
an image-side surface of the second lens is a concave surface;
an object-side surface of the third lens is a convex surface;
an object-side surface of the seventh lens is a convex surface and an image-side surface of the seventh lens is a concave surface;
the optical imaging system satisfies:
f/EPD≤1.5;
−1.5<(f2−f4)/(f2+f4)<−0.5; and
1<CT7/CT5×TAN(HFOV)<2,
where f is a total effective focal length of the optical imaging system, EPD is an entrance pupil diameter of the optical imaging system, f2 is an effective focal length of the second lens, and f4 is an effective focal length of the fourth lens, CT7 is a center thickness of the seventh lens on the optical axis, CT5 is a center thickness of the fifth lens on the optical axis, and HFOV is half of a maximal field-of-view of the optical imaging system.

### Claim 2 (depends on 1)

The optical imaging system according to claim 1, wherein the optical imaging system satisfies: −3<(R1+R2)/(R1−R2)<−2,
where R1 is a radius of curvature of the object-side surface of the first lens, and R2 is a radius of curvature of the image-side surface of the first lens.

### Claim 3 (depends on 1)

The optical imaging system according to claim 1, wherein the optical imaging system satisfies: −0.5<f/R3−f/R5<0.3,
where f is the total effective focal length of the optical imaging system, R3 is a radius of curvature of an object-side surface of the second lens, and R5 is a radius of curvature of the object-side surface of the third lens.

### Claim 4 (depends on 1)

The optical imaging system according to claim 1, wherein the optical imaging system satisfies: 1.5<DT71/DT31<2.5,
where DT71 is a maximum effective radius of the object-side surface of the seventh lens, and DT31 is a maximum effective radius of the object-side surface of the third lens.

### Claim 5 (depends on 1)

The optical imaging system according to claim 1, wherein the optical imaging system satisfies: 0.5<|SAG62/CT6|<2,
where SAG62 is an axial distance from an intersection of an image-side surface of the sixth lens and the optical axis to an apex of a maximum effective radius of the image-side surface of the sixth lens, and CT6 is a center thickness of the sixth lens on the optical axis.

### Claim 6 (depends on 1)

The optical imaging system according to claim 1, wherein the optical imaging system satisfies: 0<(1/f5+1/f6)/(1/f1+1/f3)<0.5,
where f1 is an effective focal length of the first lens, f3 is an effective focal length of the third lens, f5 is an effective focal length of the fifth lens, and f6 is an effective focal length of the sixth lens.

### Claim 7 (depends on 1)

The optical imaging system according to claim 1, wherein the optical imaging system satisfies: 1.0≤CT3/T34<1.5,
where CT3 is a center thickness of the third lens on the optical axis, and T34 is a spaced distance of the third lens and the fourth lens on the optical axis.

### Claim 8 (depends on 1)

The optical imaging system according to claim 1, wherein the optical imaging system satisfies: TTL/ImgH<1.5,
where TTL is a distance on the optical axis from the object-side surface of the first lens to an imaging plane of the optical imaging system, and ImgH is half of a diagonal length of an effective pixel area on the imaging plane of the optical imaging system.

### Claim 9 (depends on 1)

The optical imaging system according to claim 1, wherein the optical imaging system satisfies: 4.5<ΣAT/(T56+T12)<6,
where ΣAT is a sum of spaced distances on the optical axis between adjacent lenses of the first lens to the seventh lens, T56 is a spaced distance of the fifth lens and the sixth lens on the optical axis, and T12 is a spaced distance of the first lens and the second lens on the optical axis.