# US 10,502,931 B2 · Image picking-up system, image capturing apparatus and electronic device

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- Number: US 10,502,931 B2
- Document ID: US10502931B2
- Status: Granted
- Kind: B2
- Application number: 15/642,447
- Filed: 2017-07-06
- Published: 2018-07-05
- Granted: 2019-12-10
- Earliest claimed: 2017-01-04
- Assignees: Largan Precision Co., Ltd.
- Applicants: Largan Precision Co., Ltd.
- Inventors: Hsin-Hsuan Huang
- Web page: https://patentgrep.com/patent/US10502931B2

## CPC

- G02B 13/0045: {having five or more lenses}
- G02B 9/64: having more than six components
- H04N 23/54: Mounting of pick-up tubes, electronic image sensors, deviation or focusing coils
- G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION

## Abstract

An image picking-up system includes seven lens elements, which are, in order from an object side to an image side, a first lens group including a first lens element and a second lens element, a second lens group including a third lens element and a fourth lens element, and a third lens group including a fifth lens element, a sixth lens element and a seventh lens element. The third lens element has positive refractive power. The fourth lens element has an image-side surface being concave in a paraxial region thereof. At least one surface of object-side surfaces and image-side surfaces of the seven lens elements includes at least one inflection point.

## Claims

### Claim 1

An image picking-up system comprising seven lens elements, the seven lens elements being, in order from an object side to an image side:
a first lens group comprising:
a first lens element; and
a second lens element;
a second lens group comprising:
a third lens element having positive refractive power; and
a fourth lens element having an image-side surface being concave in a paraxial region thereof; and
a third lens group comprising:
a fifth lens element;
a sixth lens element; and
a seventh lens element;
wherein at least one surface of object-side surfaces and image-side surfaces of the seven lens elements comprises at least one inflection point, a focal length of the image picking-up system is f, a focal length of the first lens element is f1, a focal length of the second lens element is f2, a focal length of the third lens element is f3, an axial distance between the first lens element and the second lens element is T12, a minimum among central thicknesses of all the lens elements of the image picking-up system is CTmin, a maximum among refractive indices of all the lens elements of the image picking-up system is Nmax, and the following conditions are satisfied:
|f/f1|+|f/f2|<0.35;
0.50<f/f3<4.50
T12/CTmin<4.50; and
1.66≤Nmax<1.72.

### Claim 2 (depends on 1)

The image picking-up system of claim 1, wherein the seventh lens element with negative refractive power has an object-side surface being convex in a paraxial region thereof and an image-side surface being concave in a paraxial region thereof.

### Claim 3 (depends on 1)

The image picking-up system of claim 1, wherein the seventh lens element has an image-side surface being concave in a paraxial region thereof, a maximum among the central thicknesses of all the lens elements of the image picking-up system is CTmax, a vertical distance between a critical point in an off-axial region on the image-side surface of the seventh lens element and an optical axis is Yc72, and the following condition is satisfied:
0.20<CTmax/Yc72<4.0.

### Claim 4 (depends on 1)

The image picking-up system of claim 1, further comprising:
an aperture stop disposed in an object side of the fourth lens element, wherein an axial distance between an object-side surface of the first lens element and an image surface is TL, a maximum image height of the image picking-up system is ImgH, and the following condition is satisfied:
TL/ImgH<3.50.

### Claim 5 (depends on 1)

The image picking-up system of claim 1, wherein a sum of axial distances between every two of the lens elements that are adjacent to each other of the image picking-up system is ΣAT, a sum of the central thicknesses of all the lens elements of the image picking-up system is ΣCT, and the following condition is satisfied:
ΣAT/ΣCT<0.75.

### Claim 6 (depends on 1)

The image picking-up system of claim 1, wherein a composite focal length of the first lens group is fG1, a composite focal length of the second lens group is fG2, and the following condition is satisfied:
−0.30<fG2/fG1<0.40.

### Claim 7 (depends on 1)

The image picking-up system of claim 1, wherein a half of a maximum field of view of the image picking-up system is HFOV, an f-number of the image picking-up system is Fno, a curvature radius of an image-side surface of the second lens element is R4, a curvature radius of an object-side surface of the third lens element is R5, and the following conditions are satisfied:
0.20<tan(HFOV)<1.50;
1.20<Fno<2.60; and
−2.0<R4/R5<5.0.

### Claim 8 (depends on 1)

The image picking-up system of claim 1, wherein the focal length of the image picking-up system is f, the focal length of the third lens element is f3, an axial distance between an object-side surface of the first lens element and an image surface is TL, and the following conditions are satisfied:
0.70<f/f3<2.50; and
0.80<TL/f<2.50.

### Claim 9 (depends on 1)

The image picking-up system of claim 1, wherein an Abbe number of the third lens element is V3, an Abbe number of the fourth lens element is V4, the focal length of the image picking-up system is f, the focal length of the second lens element is f2, and the following conditions are satisfied:
1.50<V3/V4<3.50; and
−0.20<f/f2<0.50.

### Claim 10 (depends on 1)

The image picking-up system of claim 1, wherein an axial distance between an image-side surface of the seventh lens element and an image surface is BL, an axial distance between an object-side surface of the first lens element and the image surface is TL, and the following condition is satisfied:
0.10<BL/TL<0.35.

### Claim 11 (depends on 1)

The image picking-up system of claim 1, wherein a focal length of the fourth lens element is f4, a focal length of the fifth lens element is f5, and the following condition is satisfied:
|f4/f5|<2.0.

### Claim 12 (depends on 1)

The image picking-up system of claim 1, wherein an axial distance between an object-side surface of the first lens element and an image surface is TL, an entrance pupil diameter of the image picking-up system is EPD, and the following condition is satisfied:
1.0<TL/EPD<4.5.

### Claim 13 (depends on 1)

An image capturing apparatus, comprising:
the image picking-up system of claim 1; and
an image sensor, wherein the image sensor is disposed on an image surface of the image picking-up system.

### Claim 14 (depends on 13)

An electronic device, comprising:
the image capturing apparatus of claim 13.

### Claim 15

An image picking-up system comprising seven lens elements, the seven lens elements being, in order from an object side to an image side:
a first lens group comprising:
a first lens element; and
a second lens element having an object-side surface being convex in a paraxial region thereof;
a second lens group comprising:
a third lens element having positive refractive power; and
a fourth lens element; and
a third lens group comprising:
a fifth lens element;
a sixth lens element; and
a seventh lens element;
wherein at least one surface of object-side surfaces and image-side surfaces of the seven lens elements comprises at least one inflection point, a focal length of the image picking-up system is f, a focal length of the first lens element is f1, a focal length of the second lens element is f2, a focal length of the third lens element is f3, an axial distance between the first lens element and the second lens element is T12, an axial distance between the second lens element and the third lens element is T23, an axial distance between the third lens element and the fourth lens element is T34, a minimum among central thicknesses of all the lens elements of the image picking-up system is CTmin, a maximum among refractive indices of all the lens elements of the image picking-up system is Nmax, and the following conditions are satisfied:
|f/f1|+|f/f2|<0.50;
0.50<f/f3<4.50;
(T12+T23+T34)/CTmin<5.50; and
1.66≤Nmax<1.72.

### Claim 16 (depends on 15)

The image picking-up system of claim 15, wherein the sixth lens element has positive refractive power, the seventh lens element has an image-side surface being concave in a paraxial region thereof, and the image-side surface of the seventh lens element comprises at least one convex shape in an off-axial region thereof.

### Claim 17 (depends on 15)

The image picking-up system of claim 15, further comprising:
an aperture stop, wherein an axial distance between the aperture stop and an image-side surface of the seventh lens element is SD, an axial distance between an object-side surface of the first lens element and the image-side surface of the seventh lens element is TD, an axial distance between the object-side surface of the first lens element and an image surface is TL, an entrance pupil diameter of the image picking-up system is EPD, and the following conditions are satisfied:
0.50<SD/TD<1.20; and
1.0<TL/EPD<4.5.

### Claim 18 (depends on 15)

The image picking-up system of claim 15, wherein the focal length of the third lens element is f3, a focal length of the seventh lens element is f7, and the following condition is satisfied:
−3.0<f3/f7<1.0.

### Claim 19 (depends on 15)

The image picking-up system of claim 15, wherein a sum of axial distances between every two of the lens elements that are adjacent to each other of the image picking-up system is ΣAT, a sum of the central thicknesses of all the lens elements of the image picking-up system is ΣCT, and the following condition is satisfied:
ΣAT/ΣCT<0.75.

### Claim 20 (depends on 15)

The image picking-up system of claim 15, wherein a maximum among axial distances between every two of the lens elements that are adjacent to each other is ATmax, a maximum among the central thicknesses of all the lens elements of the image picking-up system is CTmax, and the following condition is satisfied:
0.10<ATmax/CTmax<1.0.

### Claim 21 (depends on 15)

The image picking-up system of claim 15, wherein a number of the lens elements of the image picking-up system having an Abbe number smaller than 30 is Nv30, and the following condition is satisfied:
2≤Nv30.

### Claim 22 (depends on 15)

The image picking-up system of claim 15, wherein a focal length of the fourth lens element is f4, a focal length of the fifth lens element is f5, and the following condition is satisfied:
|f4/f5|<2.0.

### Claim 23

An image picking-up system comprising seven lens elements, the seven lens elements being, in order from an object side to an image side:
a first lens group comprising:
a first lens element; and
a second lens element having an object-side surface being convex in a paraxial region thereof;
a second lens group comprising:
a third lens element having positive refractive power; and
a fourth lens element; and
a third lens group comprising:
a fifth lens element;
a sixth lens element; and
a seventh lens element;
wherein at least one surface of object-side surfaces and image-side surfaces of the seven lens elements comprises at least one inflection point, a focal length of the image picking-up system is f, a focal length of the first lens element is f1, a focal length of the second lens element is f2, a focal length of the third lens element is f3, a maximum among axial distances between every two of the lens elements that are adjacent to each other is ATmax, a minimum among central thicknesses of all the lens elements of the image picking-up system is CTmin, a maximum among refractive indices of all the lens elements of the image picking-up system is Nmax, and the following conditions are satisfied:
|f/f1|+|f/f2|<0.50;
0.50<f/f3<4.50;
0<ATmax/CTmin<7.50; and
1.66≤Nmax<1.72.

### Claim 24 (depends on 23)

The image picking-up system of claim 23, wherein the fourth lens element has negative refractive power, object-side surfaces and image-side surfaces of at least five of the seven lens elements are aspheric, an axial distance between an image-side surface of the seventh lens element and an image surface is BL, an axial distance between an object-side surface of the first lens element and the image surface is TL, and the following condition is satisfied:
0.10<BL/TL<0.35.

### Claim 25 (depends on 23)

The image picking-up system of claim 23, wherein the second lens element has an image-side surface being concave in a paraxial region thereof, and the third lens element has an object-side surface being convex in a paraxial region thereof.

### Claim 26 (depends on 23)

The image picking-up system of claim 23, wherein the seventh lens element has an image-side surface being concave in a paraxial region thereof, a maximum among the central thicknesses of all the lens elements of the image picking-up system is CTmax, a vertical distance between a critical point in an off-axial region on the image-side surface of the seventh lens element and an optical axis is Yc72, and the following condition is satisfied:
0.20<CTmax/Yc72<4.0.

### Claim 27 (depends on 23)

The image picking-up system of claim 23, wherein a curvature radius of an image-side surface of the second lens element is R4, a curvature radius of an object-side surface of the third lens element is R5, and the following condition is satisfied:
−2.0<R4/R5<5.0.

### Claim 28 (depends on 23)

The image picking-up system of claim 23, wherein a vertical distance between a maximum effective radius position of an object-side surface of the first lens element and an optical axis is Y11, a vertical distance between a maximum effective radius position of an image-side surface of the seventh lens element and the optical axis is Y72, and the following condition is satisfied:
0.25<Y11/Y72<1.30.

### Claim 29

An image picking-up system comprising seven lens elements, the seven lens elements being, in order from an object side to an image side:
a first lens group comprising:
a first lens element; and
a second lens element;
a second lens group comprising:
a third lens element having positive refractive power; and
a fourth lens element having negative refractive power; and
a third lens group comprising:
a fifth lens element;
a sixth lens element; and
a seventh lens element;
wherein at least one surface of object-side surfaces and image-side surfaces of the seven lens elements comprises at least one inflection point, a focal length of the image picking-up system is f, a focal length of the first lens element is f1, a focal length of the second lens element is f2, a focal length of the third lens element is f3, a focal length of the fourth lens element is f4, a focal length of the fifth lens element is f5, a maximum among refractive indices of all the lens elements of the image picking-up system is Nmax, and the following conditions are satisfied:
|f/f1|+|f/f2|<0.50;
0.50<f/f3<4.50;
−2.80<f/f4<−0.40;
−2.50<f/f5<0.70; and
1.66≤Nmax<1.72.

### Claim 30 (depends on 29)

The image picking-up system of claim 29, wherein the sixth lens element has an image-side surface being convex in a paraxial region thereof, an f-number of the image picking-up system is Fno, and the following condition is satisfied:
1.35<Fno<2.40.

### Claim 31 (depends on 29)

The image picking-up system of claim 29, wherein at least one of an object-side surface and an image-side surface of the first lens element comprises at least one inflection point, a vertical distance between a maximum effective radius position of the object-side surface of the first lens element and an optical axis is Y11, a vertical distance between a maximum effective radius position of an image-side surface of the seventh lens element and the optical axis is Y72, and the following condition is satisfied:
0.25<Y11/Y72<1.30.

### Claim 32 (depends on 29)

The image picking-up system of claim 29, wherein the seventh lens element has an image-side surface being concave in a paraxial region thereof, a curvature radius of an object-side surface of the seventh lens element is R13, a curvature radius of the image-side surface of the seventh lens element is R14, and the following condition is satisfied:
0<(R13+R14)/(R13−R14)<10.0.

### Claim 33 (depends on 29)

The image picking-up system of claim 29, wherein a central thickness of the first lens element is CT1, a central thickness of the sixth lens element is CT6, and the following condition is satisfied:
0<CT1/CT6<1.0.

### Claim 34 (depends on 29)

The image picking-up system of claim 29, wherein at least one surface of object-side surfaces and image-side surfaces of the sixth lens element and the seventh lens element comprises at least one inflection point.

### Claim 35 (depends on 29)

The image picking-up system of claim 29, wherein a curvature radius of an object-side surface of the second lens element is R3, a curvature radius of an object-side surface of the third lens element is R5, and the following condition is satisfied:
−3.50<(R3−R5)/(R3+R5)<2.50.