# US 2021/0278637 A1 · Optical imaging system

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- Number: US 2021/0278637 A1
- Document ID: US20210278637A1
- Status: Published application
- Kind: A1
- Application number: 17/141,862
- Filed: 2021-01-05
- Published: 2021-09-09
- Earliest claimed: 2020-03-04
- Assignees: Zhejiang Sunny Optics Co., Ltd.
- Applicants: Zhejiang Sunny Optics Co., Ltd
- Inventors: Yuhao Wang; Yang Li; Lingbo He; Fujian Dai; Liefeng Zhao
- Web page: https://patentgrep.com/patent/US20210278637A1

## CPC

- G02B 9/60: having five 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

The present disclosure discloses an optical imaging system including, sequentially from an object side to an image side along an optical axis, a first lens having refractive power; a second lens having negative refractive power; a third lens having negative refractive power; a fourth lens having refractive power, a convex object-side surface and a concave image-side surface; and a fifth lens having refractive power. A distance TTL along the optical axis from an object-side surface of the first lens to an imaging plane of the optical imaging system and half of a diagonal length ImgH of an effective pixel area on the imaging plane of the optical imaging system satisfy: 1.0<TTL/ImgH<1.5.

## Claims

### Claim 1

An optical imaging system, sequentially from an object side to an image side of the optical imaging system along an optical axis, comprising:
a first lens having refractive power;
a second lens having negative refractive power;
a third lens having negative refractive power;
a fourth lens having refractive power, a convex object-side surface and a concave image-side surface; and
a fifth lens having refractive power,
wherein 1.0<TTL/ImgH<1.5,
where TTL is a distance along the optical axis from an 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 2 (depends on 1)

The optical imaging system according to claim 1, wherein 5.5<ΣAT/T34<9.0,
where ΣAT is a sum of the spaced intervals along the optical axis between each two adjacent lenses of the first lens to the fifth lens, and T34 is a spaced interval between the third lens and the fourth lens along the optical axis.

### Claim 3 (depends on 1)

The optical imaging system according to claim 1, wherein −2.0<f/(f2+f4)<−0.5,
where f is a total effective focal length 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.

### Claim 4 (depends on 1)

The optical imaging system according to claim 1, wherein 1.5<(T12+T45)/T23<3.5,
where T12 is a spaced interval between the first lens and the second lens along the optical axis, T23 is a spaced interval between the second lens and the third lens along the optical axis, and T45 is a spaced interval between the fourth lens and the fifth lens along the optical axis.

### Claim 5 (depends on 1)

The optical imaging system according to claim 1, wherein 1.1<f4/(|R8|+R10)<2.0,
where f4 is an effective focal length of the fourth lens, R8 is a radius of curvature of the image-side surface of the fourth lens, and R10 is a radius of curvature of an image-side surface of the fifth lens.

### Claim 6 (depends on 1)

The optical imaging system according to claim 1, wherein 2.0<(|R6|+R3)/(R2+R4)<5.0,
where R2 is a radius of curvature of an image-side surface of the first lens, R3 is a radius of curvature of an object-side surface of the second lens, R4 is a radius of curvature of an image-side surface of the second lens, and R6 is a radius of curvature of an image-side surface of the third lens.

### Claim 7 (depends on 1)

The optical imaging system according to claim 1, wherein 3.0<CT4/T34<6.5,
where CT4 is a center thickness of the fourth lens along the optical axis, and T34 is a spaced interval between the third lens and the fourth lens along the optical axis.

### Claim 8 (depends on 1)

The optical imaging system according to claim 1, wherein 1.0<ET5/ET1<3.5,
where ET5 is an edge thickness of the fifth lens, and ET1 is an edge thickness of the first lens.

### Claim 9 (depends on 1)

The optical imaging system according to claim 1, wherein 1.0<f23/f5<2.0,
where f23 is a combined focal length of the second lens and the third lens, and f5 is an effective focal length of the fifth lens.

### Claim 10 (depends on 1)

The optical imaging system according to claim 1, wherein 1.5<CT4/ET4<2.0,
where CT4 is a center thickness of the fourth lens along the optical axis, and ET4 is an edge thickness of the fourth lens.

### Claim 11 (depends on 1)

The optical imaging system according to claim 1, wherein 1.0<f12/f<1.5,
where f12 is a combined focal length of the first lens and the second lens, and f is a total effective focal length of the optical imaging system.

### Claim 12 (depends on 1)

The optical imaging system according to claim 1, wherein 1.5<DT51/(DT11+DT21)<2.0,
where DT11 is a maximum effective radius of the object-side surface of the first lens, DT21 is a maximum effective radius of an object-side surface of the second lens, and DT51 is a maximum effective radius of an object-side surface of the fifth lens.

### Claim 13 (depends on 1)

The optical imaging system according to claim 1, wherein 1.5<CT5/CT3<3.5,
where CT5 is a center thickness of the fifth lens along the optical axis, and CT3 is a center thickness of the third lens along the optical axis.

### Claim 14

An optical imaging system, sequentially from an object side to an image side of the optical imaging system along an optical axis, comprising:
a first lens having refractive power;
a second lens having negative refractive power;
a third lens having negative refractive power;
a fourth lens having refractive power; and
a fifth lens having refractive power,
wherein 1.0<ETL/EIN<1.5,
where ETL is a distance from an object-side surface of the first lens to an imaging plane of the optical imaging system parallel to the optical axis at ½ of an entrance pupil diameter of the optical imaging system, and EIN is a distance from the object-side surface of the first lens to an image-side surface of the fifth lens parallel to the optical axis at ½ of the entrance pupil diameter of the optical imaging system.

### Claim 15 (depends on 14)

The optical imaging system according to claim 14, wherein 5.5<ΣAT/T34<9.0,
where ΣAT is a sum of the spaced intervals along the optical axis between each two adjacent lenses of the first lens to the fifth lens, and T34 is a spaced interval between the third lens and the fourth lens along the optical axis.

### Claim 16 (depends on 14)

The optical imaging system according to claim 14, wherein −2.0<f/(f2+f4)<−0.5,
where f is a total effective focal length 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.

### Claim 17 (depends on 14)

The optical imaging system according to claim 14, wherein 1.1<f4/(|R8|+R10)<2.0,
where f4 is an effective focal length of the fourth lens, R8 is a radius of curvature of an image-side surface of the fourth lens, and R10 is a radius of curvature of the image-side surface of the fifth lens.

### Claim 18 (depends on 14)

The optical imaging system according to claim 14, wherein 2.0<(|R6|+R3)/(R2+R4)<5.0,
where R2 is a radius of curvature of an image-side surface of the first lens, R3 is a radius of curvature of an object-side surface of the second lens, R4 is a radius of curvature of an image-side surface of the second lens, and R6 is a radius of curvature of an image-side surface of the third lens.

### Claim 19 (depends on 14)

The optical imaging system according to claim 14, wherein 1.0<f23/f5<2.0,
where f23 is a combined focal length of the second lens and the third lens, and f5 is an effective focal length of the fifth lens.

### Claim 20 (depends on 14)

The optical imaging system according to claim 14, wherein 1.0<f12/f<1.5,
where f12 is a combined focal length of the first lens and the second lens, and f is a total effective focal length of the optical imaging system.