Granted Patent B2

US 12,541,079 · App. 18/386,755 · Granted Feb 3, 2026

Inventors: Yu Jui Lin (Taichung, TW); Shih-Han Chen (Taichung, TW); Guang-Yan Liu (Taichung, TW); Yu-Han Shih (Taichung, TW); Hsin-Hsuan Huang (Taichung, TW)

Assignee: LARGAN PRECISION CO., LTD.

G02B13/0035

Abstract

Claims (271)

1 . An imaging lens assembly comprising three lens elements, the three lens elements being, in order from an object side to an image side along an optical path, a first lens element, a second lens element and a third lens element, and each of the three lens elements having an object-side surface facing toward the object side and an image-side surface facing toward the image side;

wherein the object-side surface of the second lens element is concave in a paraxial region thereof, and at least one surface of at least one lens element in the imaging lens assembly has at least one inflection point;

wherein a curvature radius of the object-side surface of the first lens element is R1, a curvature radius of the object-side surface of the second lens element is R3, and a curvature radius of the image-side surface of the second lens element is R4;

and with a wavelength of helium d-line as a reference wavelength for the imaging lens assembly, an axial distance between the object-side surface of the first lens element and an image surface is TLd, an entrance pupil diameter of the imaging lens assembly is EPDd, an Abbe number of the first lens element is V1d, an Abbe number of the second lens element is V2d, an Abbe number of the third lens element is V3d, a focal length of the imaging lens assembly is fd, and a focal length of the first lens element is f1d, and the following conditions are satisfied:

1.75

<

TLd

/

EPDd

<

2.8

;

0.75

<

(

R

⁢

1

-

R

⁢

3

)

/

(

R

⁢

1

+

R

⁢

3

)

<

2.55

;

0.5

<

(

R

⁢

1

-

R

⁢

4

)

/

(

R

⁢

1

+

R

⁢

4

)

<

4

.20

;

30.

<

V

⁢

1

⁢

d

+

V

⁢

2

⁢

d

+

V

⁢

3

⁢

d

<

105.

;

and

0.7

<

fd

/

f

⁢

1

⁢

d

<

1

.

7

⁢

0

.

wherein a maximum effective radius of the object-side surface of the first lens element is Y1R1, a maximum effective radius of the image-side surface of the third lens element is Y3R2, a displacement in parallel with an optical axis from an axial vertex of the image-side surface of the first lens element to a maximum effective radius position of the image-side surface of the first lens element is SAG1R2, a central thickness of the first lens element is CT1, and the following conditions are satisfied:

1.1

<

Y

⁢

3

⁢

R

⁢

2

/

Y

⁢

1

⁢

R

⁢

1

<

2.

;

and

-

0.6

⁢

5

<

SAG

⁢

1

⁢

R

⁢

2

/

CT

⁢

1

<

0

.

2 . The imaging lens assembly of claim 1 , wherein the first lens element has positive refractive power, the object-side surface of the first lens element is convex in a paraxial region thereof, the image-side surface of the second lens element is convex in a paraxial region thereof, the object-side surface of the third lens element has at least one inflection point, and there is an air gap in a paraxial region between each of all adjacent lens elements of the imaging lens assembly.

3 . The imaging lens assembly of claim 1 , wherein an axial distance between the object-side surface of the first lens element and the image-side surface of the third lens element is TD, an axial distance between the second lens element and the third lens element is T23, and the following condition is satisfied:

22.9

<

TD

/

T

⁢

23

<

4

⁢

5

.

9

⁢

0

.

4 . The imaging lens assembly of claim 1 , wherein with the wavelength of helium d-line as the reference wavelength for the imaging lens assembly, the Abbe number of the first lens element is V1d, the Abbe number of the second lens element is V2d, the Abbe number of the third lens element is V3d, the focal length of the first lens element is f1d, and a composite focal length of the first lens element and the second lens element is f12d, and the following conditions are satisfied:

30.

<

V

⁢

1

⁢

d

+

V

⁢

2

⁢

d

+

V

⁢

3

⁢

d

<

96.

;

and

0.

<

f

⁢

12

⁢

d

/

f

⁢

1

⁢

d

.

5 . The imaging lens assembly of claim 1 , further comprising an aperture stop, wherein the curvature radius of the object-side surface of the second lens element is R3; and

with the wavelength of helium d-line as the reference wavelength for the imaging lens assembly, the focal length of the imaging lens assembly is fd, a composite focal length of the first lens element and the second lens element is f12d, a composite focal length of the second lens element and the third lens element is f23d, and an axial distance between the aperture stop and the image surface is SLd, and the following conditions are satisfied:

7.3

<

❘

"\[LeftBracketingBar]"

fd

/

R

⁢

3

❘

"\[RightBracketingBar]"

+

❘

"\[LeftBracketingBar]"

SLd

/

R

⁢

3

❘

"\[RightBracketingBar]"

<

13.5

;

and

1.1

<

❘

"\[LeftBracketingBar]"

f

⁢

23

⁢

d

/

f

⁢

12

⁢

d

|

<

1

⁢

5

.

1

⁢

0

.

6 . The imaging lens assembly of claim 1 , wherein a maximum image height of the imaging lens assembly is ImgH; and

with the wavelength of helium d-line as the reference wavelength for the imaging lens assembly, the axial distance between the object-side surface of the first lens element and the image surface is TLd, and the following condition is satisfied:

2.

<

TLd

/

ImgH

<

3.5

.

7 . The imaging lens assembly of claim 1 , wherein with the wavelength of helium d-line as the reference wavelength for the imaging lens assembly, half of a maximum field of view of the imaging lens assembly is HFOVd, and the following condition is satisfied:

0.38<tan( HFOVd )<0.68.

8 . The imaging lens assembly of claim 1 , wherein a chief ray angle of a maximum field of view on the image surface of the imaging lens assembly is CRA, and the following condition is satisfied:

0.16<tan( CRA )<0.63.

9 . The imaging lens assembly of claim 1 , wherein at least two lens elements of the imaging lens assembly are made of plastic material;

wherein a wavelength of light incident into the imaging lens assembly is λ, and the following condition is satisfied:

780 nm<λ<1200 nm.

10 . An image capturing unit comprising:

the imaging lens assembly of claim 1 ; and

an image sensor disposed on the image surface of the imaging lens assembly.

11 . An electronic device comprising:

the image capturing unit of claim 10 .

Assignments (1)

Priority Claims (1)

Continuity (1)

References Cited (60)