Projection lens assembly

Patent metadata

Field	Value
Publication number	US-10996433-B2
Application number	US-201816231147-A
Country	US
Kind code	B2
Filing date	Dec 21, 2018
Priority date	Nov 21, 2017
Publication date	May 4, 2021
Grant date	May 4, 2021

Abstract

A projection lens assembly is provided. The projection lens assembly includes sequentially from a source-side to an image-side along an optical axis: a first lens and a second lens. The first lens has a negative refractive power, a source-side surface of the first lens is a concave surface, and an image-side surface of the first lens is a convex surface. The second lens has a positive refractive power, and an image-side surface of the second lens is a convex surface.

First claim

What is claimed is:

1. A projection lens assembly comprising, from a source-side to an image-side along an optical axis, a first lens and a second lens sequentially, wherein,
the first lens has a negative refractive power, a source-side surface of the first lens is a concave surface, and an image-side surface of the first lens is a convex surface; and
the second lens has a positive refractive power, and an image-side surface of the second lens is a convex surface,
wherein a half of a maximum field-of-view HFOV of the projection lens assembly satisfies: HFOV<15°.

2. The projection lens assembly according to claim 1 , wherein an object-side numerical aperture NA of the projection lens assembly satisfies: NA≥0.18.

3. The projection lens assembly according to claim 2 , wherein a total track length TTL of the projection lens assembly satisfies: 3 mm<TTL<3.7 mm.

4. The projection lens assembly according to claim 1 , wherein for a light wave band of 800 nm to 1000 nm, a light transmittance of the projection lens assembly is greater than 85%.

5. The projection lens assembly according to claim 1 , wherein an effective focal length f 2 of the second lens and a total effective focal length f of the projection lens assembly satisfy: 0.7<f 2 /f<1.2.

6. The projection lens assembly according to claim 1 , wherein a radius R 4 of curvature of the image-side surface of the second lens and a total effective focal length f of the projection lens assembly satisfy: −0.6<R 4 /f<−0.2.

7. The projection lens assembly according to claim 1 , wherein a radius R 2 of curvature of the image-side surface of the first lens and a radius R 1 of curvature of the source-side surface of the first lens satisfy: (R 2 −R 1 )/(R 2 +R 1 )<0.5.

8. The projection lens assembly according to claim 1 , wherein an effective half aperture DT 22 of the image-side surface of the second lens and an effective half aperture DT 21 of a source-side surface of the second lens satisfy: 1.0<DT 22 /DT 21 <1.3.

9. A projection lens assembly comprising, from a source-side to an image-side along an optical axis, a first lens and a second lens sequentially, wherein,
the first lens has a negative refractive power, a source-side surface of the first lens is a concave surface, and an image-side surface of the first lens is a convex surface;
the second lens has a positive refractive power, and an image-side surface of the second lens is a convex surface; and
wherein a total track length TTL of the projection lens assembly satisfies: 3 mm<TTL<3.7 mm.

10. The projection lens assembly according to claim 9 , wherein a half of a maximum field-of-view HFOV of the projection lens assembly satisfies: HFOV<15°.

11. The projection lens assembly according to claim 10 , wherein an object-side numerical aperture NA of the projection lens assembly satisfies: NA≥0.18.

12. The projection lens assembly according to claim 9 , wherein for a light wave band of 800 nm to 1000 nm, a light transmittance of the projection lens assembly is greater than 85%.

13. The projection lens assembly according to claim 9 , wherein a radius R 2 of curvature of the image-side surface of the first lens and a radius of curvature R 1 of the source-side surface of the first lens satisfy: (R 2 −R 1 )/(R 2 +R 1 )<0.5.

14. The projection lens assembly according to claim 9 , wherein an effective half aperture DT 22 of the image-side surface of the second lens and an effective half aperture DT 21 of a source-side surface of the second lens satisfy: 1.0<DT 22 /DT 21 <1.3.

15. The projection lens assembly according to claim 9 , wherein a radius R 4 of curvature of the image-side surface of the second lens and a total effective focal length f of the projection lens assembly satisfy: −0.6<R 4 /f<−0.2.

16. The projection lens assembly according to claim 9 , wherein an effective focal length f 2 of the second lens and a total effective focal length f of the projection lens assembly satisfy: 0.7<f 2 /f<1.2.

Assignees

• Zhejiang Sunny Optical Co Ltd

Inventors

• Huang Lin
• Wang Xinquan

Classifications

• G02B9/10

  one + and one - component · CPC title

• G02B13/008

  designed for infrared light · CPC title

• G02B13/16

  for use in conjunction with image converters or intensifiers {, or for use with projectors, e.g. objectives for projection TV} · CPC title

• G02B13/003 Primary

  having two lenses · CPC title