Optical imaging lens assembly, image capturing unit and electronic device

• US 11,106,009 B2
• Filed: 01/23/2019
• Issued: 08/31/2021
• Est. Priority Date: 12/03/2018
• Status: Active Grant

• Current Assignee: Largan Precision Co Limited (Largan Precision)
• Original Assignee: Largan Precision Co Limited (Largan Precision)
• Inventors: Lin, Yu Jui, Kuo, Tzu-Chieh
• Primary Examiner(s): Alexander, William R
• Assistant Examiner(s): Broome, Sharrief I
• Application Number:
  US16/255,533
• Publication Number:
  US 20200174226A1
• Time in Patent Office: 951 Days
• CPC Class Codes: G02B 13/0035 having three lenses
• CPC Class Codes: G02B 13/04 Reversed telephoto objectives
• CPC Class Codes: G02B 9/12 having three components only
• CPC Class Codes: G06V 40/1318 using electro-optical elements or layers, e.g. electroluminescent sensing

Abstract

An optical imaging lens assembly includes three lens elements which are, in order from an object side to an image side: a first lens element, a second lens element and a third lens element. Each of the three lens elements 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. The object-side surface of the first lens element is aspheric and has at least one inflection point. The object-side surface of the first lens element has at least one critical point in an off-axis region thereof. The optical imaging lens assembly has a total of three lens elements.

Claims

1. An optical imaging lens assembly comprising three lens elements, the three lens elements being, in order from an object side to an image side, 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 first lens element is concave in a paraxial region thereof, the object-side surface of the first lens element is aspheric and has at least one inflection point, the object-side surface of the first lens element has at least one critical point in an off-axis region thereof, and the optical imaging lens assembly has a total of three lens elements;

wherein a focal length of the optical imaging lens assembly is f, an entrance pupil diameter of the optical imaging lens assembly is EPD, a maximum field of view of the optical imaging lens assembly is FOV, an axial distance between the object-side surface of the first lens element and an image surface is TL, and the following conditions are satisfied;

0.50<

f/EPD<

1.9;

100.0 [deg.]<

FOV<

130.0 [deg.]; and

8.80≤

TL/EPD<

16.0.

2. The optical imaging lens assembly of claim 1, wherein an Abbe number of the first lens element is V1, an Abbe number of the second lens element is V2, an Abbe number of the third lens element is V3, and the following conditions are satisfied:

45.0<

V1<

60.0;

45.0<

V2<

60.0; and

45.0<

V3<

60.0.

3. The optical imaging lens assembly of claim 1, wherein a maximum value among Abbe numbers of all lens elements of the optical imaging lens assembly is Vmax, a minimum value among Abbe numbers of all lens elements of the optical imaging lens assembly is Vmin, a sum of central thicknesses of all lens elements of the optical imaging lens assembly is Σ

CT, a sum of axial distances between each of all adjacent lens elements of the optical imaging lens assembly is Σ

AT, and the following conditions are satisfied;

Vmax−

Vmin<

15.0; and

1.2<

Σ

CT/Σ

AT<

2.8.

4. The optical imaging lens assembly of claim 1, wherein 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, and the following condition is satisfied:

12.5<

T12/T23<

30.0.

5. The optical imaging lens assembly of claim 1, wherein the axial distance between the object-side surface of the first lens element and the image surface is TL, the focal length of the optical imaging lens assembly is f, and the following condition is satisfied:

5.9<

TL/f<

8.5.

6. The optical imaging lens assembly of claim 1, wherein a curvature radius of the object-side surface of the first lens element is R1, the focal length of the optical imaging lens assembly is f, and the following condition is satisfied:

−

2.5<

R1/f<

0.

7. The optical imaging lens assembly of claim 1, wherein the focal length of the optical imaging lens assembly is f, the entrance pupil diameter of the optical imaging lens assembly is EPD, half of the maximum field of view of the optical imaging lens assembly is HFOV, and the following condition is satisfied:

1.0<

f/EPD+cot(HFOV)<

2.3.

8. The optical imaging lens assembly of claim 1, wherein the first lens element has negative refractive power, the focal length of the optical imaging lens assembly 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, and the following conditions are satisfied:

|f/f1|<

0.50;

|f/f2|<

0.80; and

|f/f3|<

0.80.

9. The optical imaging lens assembly of claim 1, wherein the third lens element has positive refractive power, the object-side surface of the third lens element is convex in a paraxial region thereof, the object-side surface of the third lens element is aspheric and has at least one inflection point, the object-side surface of the third lens element has at least one concave critical point in an off-axis region thereof, and the image-side surface of the third lens element is convex in a paraxial region thereof.

10. The optical imaging lens assembly of claim 1, wherein each of at least two lens elements of the optical imaging lens assembly has at least one aspheric surface having at least one inflection point, the axial distance between the object-side surface of the first lens element and the image surface is TL, the entrance pupil diameter of the optical imaging lens assembly is EPD, and the following conditions are satisfied:

TL<

3.0[mm]; and

9.01<

TL/EPD<

11.0.

11. The optical imaging lens assembly of claim 1, wherein each of at least two lens elements of the optical imaging lens assembly has at least one lens surface having at least one critical point in an off-axis region thereof, a maximum effective radius of the object-side surface of the first lens element is Y11, a maximum effective radius of the image-side surface of the third lens element is Y32, a vertical distance between the critical point on the object-side surface of the first lens element and an optical axis is Yc11, and the following conditions are satisfied:

1.25<

Y11/Y32<

2.40; and

0.30<

Yc11/Y11<

0.90.

12. The optical imaging lens assembly of claim 1, wherein at least three lens elements of the optical imaging lens assembly are made of plastic material, and the optical imaging lens assembly is operated within a wavelength range of 480 nm to 600 nm.

13. An image capturing unit, comprising:

the optical imaging lens assembly of claim 1; and

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

14. An electronic device, comprising:

a fingerprint identification module comprising the image capturing unit of claim 13.

15. An optical imaging lens assembly comprising three lens elements, the three lens elements being, in order from an object side to an image side, 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 first lens element is concave in a paraxial region thereof, the object-side surface of the first lens element is aspheric and has at least one inflection point, the object-side surface of the first lens element has at least one critical point in an off-axis region thereof, the image-side surface of the second lens element is concave in a paraxial region thereof, and the optical imaging lens assembly has a total of three lens elements;

wherein a curvature radius of the object-side surface of the first lens element is R1, an entrance pupil diameter of the optical imaging lens assembly is EPD, and the following condition is satisfied;

−

4.0<

R1/EPD<

0.

16. The optical imaging lens assembly of claim 15, wherein the curvature radius of the object-side surface of the first lens element is R1, the entrance pupil diameter of the optical imaging lens assembly is EPD, and the following condition is satisfied:

−

3.0<

R1/EPD<

−

1.0.

17. The optical imaging lens assembly of claim 15, wherein an axial distance between the object-side surface of the first lens element and an image surface is TL, a maximum field of view of the optical imaging lens assembly is FOV, and the following conditions are satisfied:

TL<

3.0 [mm]; and

100.0 [deg.]<

FOV<

130.0 [deg.].

18. The optical imaging lens assembly of claim 15, wherein the first lens element has negative refractive power, the third lens element has positive refractive power, and the image-side surface of the third lens element is convex in a paraxial region thereof.