Optical imaging system, image capturing unit and electronic device

Patent metadata

Field	Value
Publication number	US-12481128-B2
Application number	US-202217693033-A
Country	US
Kind code	B2
Filing date	Mar 11, 2022
Priority date	Mar 26, 2019
Publication date	Nov 25, 2025
Grant date	Nov 25, 2025

Abstract

An optical imaging system includes four lens elements which are, in order from an object side to an image side: a first lens element, a second lens element, a third lens element and a fourth lens element. Each of the four lens elements of the optical imaging system has an object-side surface facing toward the object side and an image-side surface facing toward the image side. The object-side surface of the first lens element is concave in a paraxial region thereof and has at least one convex shape in an off-axis region thereof. The object-side surface of the first lens element is aspheric. The image-side surface of the fourth lens element is concave in a paraxial region thereof. The optical imaging system has a total of four lens elements.

First claim

What is claimed is:

1 . An optical imaging system comprising four lens elements, the four lens elements being, in order from an object side to an image side, a first lens element, a second lens element, a third lens element and a fourth lens element; each of the four lens elements having an object-side surface facing toward the object side and an image-side surface facing toward the image side;
wherein the first lens element has negative refractive power, the object-side surface of the first lens element is concave in a paraxial region thereof and has at least one convex shape in an off-axis region thereof, the object-side surface of the first lens element is aspheric, the third lens element has positive refractive power, the fourth lens element has negative refractive power, and a total number of lens elements in the optical imaging system is four; wherein the optical imaging system further comprises an aperture stop, an axial distance between the object-side surface of the first lens element and an image surface is TL, a focal length of the optical imaging system is f, an axial distance between the aperture stop and the image-side surface of the fourth lens element is SD, an axial distance between the object-side surface of the first lens element and the image-side surface of the fourth lens element is TD, an Abbe number of the fourth lens element is V4, and the following conditions are satisfied:

3.51
≤

T
⁢

L
/
f

<

1
⁢
0.0

;

0.3
⁢
4

<

S
⁢

D
/
T

⁢
D

≤

0
⁢
.58

;

1
⁢

0
.
0

<

V
⁢
4

<
23.0

;
and

0.50
⁢

⁢
mm

<
TL
<

4.0
⁢

⁢

mm
.

2 . The optical imaging system of claim 1 , wherein the image-side surface of the first lens element is concave in a paraxial region thereof, and the second lens element has positive refractive power.

3 . The optical imaging system of claim 1 , wherein the the object-side surface of the third lens element is convex in a paraxial region thereof, and the image-side surface of the third lens element is convex in a paraxial region thereof.

4 . The optical imaging system of claim 1 , wherein the image-side surface of the second lens element is convex in a paraxial region thereof.

5 . The optical imaging system of claim 1 , wherein the object-side surface of the fourth lens element is concave in a paraxial region thereof.

6 . The optical imaging system of claim 1 , wherein the Abbe number of the fourth lens element is V4, and the following condition is satisfied:

1
⁢

0
.
0

<

V
⁢
4

≤

2
⁢

0
.
4
.

7 . The optical imaging system of claim 1 , wherein a central thickness of the first lens element is CT1, a central thickness of the third lens element is CT3, a central thickness of the fourth lens element is CT4, and the following conditions are satisfied:

CT
⁢

⁢
1

<

CT
⁢

⁢
3

;
and

CT
⁢

⁢
4

<

CT
⁢

3
.

8 . The optical imaging system of claim 1 , wherein a curvature radius of the object-side surface of the second lens element is R3, a curvature radius of the image-side surface of the second lens element is R4, and the following condition is satisfied:

-

0
.
4

⁢
5

<

(

R
⁢

⁢
3

-

R
⁢

⁢
4

)

/

(

R
⁢
3

+

R
⁢
4

)

Assignees

• Largan Precision Co Ltd

Inventors

• Tseng Yu-Tai
• Huang Hsin-Hsuan

Classifications

• G02B9/58

  arranged - + + - · CPC title

• G02B9/34

  having four components only · CPC title

• G02B13/18

  with lenses having one or more non-spherical faces, e.g. for reducing geometrical aberration {(G02B13/002 takes precedence)} · CPC title

• G02B13/06

  Panoramic objectives; So-called "sky lenses" {including panoramic objectives having reflecting surfaces} · CPC title

• G02B13/004 Primary

  having four lenses · CPC title