Optical system and display device

Patent metadata

Field	Value
Publication number	US-12487467-B2
Application number	US-202318338511-A
Country	US
Kind code	B2
Filing date	Jun 21, 2023
Priority date	Jun 22, 2022
Publication date	Dec 2, 2025
Grant date	Dec 2, 2025

Abstract

An optical system and a display device are provided. The optical system includes an optic group, a polarizing transflective film, a phase retardation film, and a transflective film. The optic group includes a first optic and a second optic; the polarizing transflective film and the phase retardation film are on one side of the optic group, the transflective film is on the other side of the optic group. The first optic includes a plane surface and a first aspheric surface having a curvature radius of −120 mm to −140 mm, the second optic includes a second aspheric surface having a curvature radius of −175 mm to −185 mm and a third aspheric surface having a curvature radius of −100 mm to −110 mm; a focal length of the optical system is 26 mm to 30 mm, an effective aperture of the optic group is 55 μm to 58 μm.

First claim

The invention claimed is:

1 . An optical system, comprising:
an optic group, comprising a first optic and a second optic which are arranged one on top of the other; a polarizing transflective film, arranged at a side of the first optic away from the second optic; a phase retardation film, arranged between the polarizing transflective film and the first optic; a transflective film, arranged at a side of the second optic away from the first optic, wherein the first optic comprises a plane surface and a first aspheric surface, and the second optic comprises a second aspheric surface and a third aspheric surface, the second aspheric surface is located at a side of the first aspheric surface away from the plane surface, and the third aspheric surface is located at a side of the second aspheric surface away from the first optic; both of the first aspheric surface and the third aspheric surface are convex surfaces, the second aspheric surface is a concave surface, and a side of the plane surface away from the first aspheric surface is a light exiting side of the optic group; and a focal length of the optical system is 26 mm to 30 mm, an effective aperture of the optic group is 55 μm to 58 μm, a curvature radius of the first aspheric surface is −120 mm to −140 mm, a curvature radius of the second aspheric surface is −175 mm to −185 mm, and a curvature radius of the third aspheric surface is −100 mm to −110 mm.

2 . The optical system according to claim 1 , wherein a maximum thickness of the first optic is 4 mm to 6 mm, a maximum thickness of the second optic is 3.5 mm to 5.5 mm, and a distance between the first optic and the second optic is 2 mm to 6 mm.

3 . The optical system according to claim 1 , wherein an eye relief of the optical system is 13 mm to 21 mm.

4 . The optical system according to claim 3 , wherein the eye relief of the optical system is not smaller than 15 mm.

5 . The optical system according to claim 3 , wherein a maximum angle of field of view (FOV) of the optical system is 100° to 110°.

6 . The optical system according to claim 1 , wherein a focal length of the first optic is 220 mm to 250 mm, and a focal length of the second optic is 400 mm to 450 mm.

7 . The optical system according to claim 1 , wherein a refractive index of the first optic is the same as a refractive index of the second optic.

8 . The optical system according to claim 7 , wherein the refractive index of the first optic and the refractive index of the second optic both are 1.5 to 1.6.

9 . The optical system according to claim 1 , wherein a radius of a spot in a spot diagram of the optical system for central field of view (FOV) is smaller than a radius of an Airy spot of the optical system.

10 . The optical system according to claim 1 , wherein the phase retardation film and the polarizing transflective film are attached onto the plane surface.

11 . The optical system according to claim 2 , wherein an eye relief of the optical system is 13 mm to 21 mm.

12 . The optical system according to claim 2 , wherein a focal length of the first optic is 220 mm to 250 mm, and a focal length of the second optic is 400 mm to 450 mm.

13 . The optical system according to claim 2 , wherein a radius of a spot in a spot diagram of the optical system for central field of view (FOV) is smaller than a radius of an Airy spot of the optical system.

14 . A display device, comprising a display screen and the optical system according to claim 1 , wherein
the display screen is located at a side of the second optic away from the first optic.

15 . The display device according to claim 14 , wherein a distance between the third aspheric surface and a display surface of the display screen is 12 mm to 15 mm.

16 . The display device according to claim 15 , wherein a distance between the plane surface and the display surface is 24 mm to 26 mm.

17 . The display device according to claim 14 , wherein a size of a display surface of the display screen is 2 inches to 3 inches.

Assignees

• Beijing Zitiao Network Technology Co Ltd

Inventors

• Wang Yuanpeng
• Luo Sheng

Classifications

• G02B27/0172 Primary

  characterised by optical features · 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

• G02B2027/0123

  comprising devices increasing the field of view · CPC title

• G02B5/3083

  Birefringent or phase retarding elements (G02B5/3008, G02B5/3016 take precedence; systems for polarisation control G02B27/286; manufacturing phase modulating patterns by lithographic processes G03F7/001) · CPC title

• G02B27/0955 Primary

  Lenses (lenses per se G02B3/00) · CPC title