Optical device and near-eye display apparatus

Patent metadata

Field	Value
Publication number	US-12038586-B2
Application number	US-202217992416-A
Country	US
Kind code	B2
Filing date	Nov 22, 2022
Priority date	Feb 28, 2019
Publication date	Jul 16, 2024
Grant date	Jul 16, 2024

Abstract

A near-eye display apparatus is disclosed. The near-eye display apparatus includes a lens and an optical path folding assembly. The lens is configured to receive incident light of a first image, which is projected by a micro-display, and shape the first image; the lens includes a primary optical axis and a first lens face and a second lens face which are opposed in a first direction where the primary optical axis of the lens is positioned, a curvature radius of the first lens face is within a range of 70 to 100 millimeters, and a curvature radius of the second lens face is within a range of 10 to 30 millimeters; and the optical path folding assembly is configured to receive light of the first image shaped by the lens and fold an optical path from the lens to an exit pupil of the near-eye display apparatus.

First claim

What is claimed is:

1. An optical device, comprising a lens and an optical path folding assembly,
wherein the lens is configured to receive incident light of a first image and shape the first image, and the incident light is projected by a micro-display,
the lens comprises a primary optical axis, a first lens face and a second lens face, and the first lens face and the second lens face are opposed in a first direction where the primary optical axis of the lens is positioned, wherein a curvature radius of the first lens face is within a range of 70 to 100 millimeters, and a curvature radius of the second lens face is within a range of 10 to 30 millimeters; and
the optical path folding assembly is configured to receive light of the first image shaped by the lens and fold an optical path from the lens to an exit pupil of the optical device.

2. The optical device according to claim 1 , wherein both the first lens face and the second lens face are aspheric surfaces.

3. The optical device according to claim 1 , wherein the optical path folding assembly comprises a first transmission reflection element and a second transmission reflection element which are opposed in a second direction intersecting with the first direction, the light of the first image is sequentially reflected by the first transmission reflection element, reflected by the second transmission reflection element, and transmitted by the first transmission reflection element.

4. The optical device according to claim 3 , wherein the first transmission reflection element is a specular transmission reflection element.

5. The optical device according to claim 3 , wherein the second transmission reflection element is a curved transmission reflection element, and a curved surface of the second transmission reflection element, which faces the exit pupil of the optical device, is a concave curved surface.

6. The optical device according to claim 3 , wherein a primary optical axis of the second transmission reflection element is in parallel with the second direction;
the primary optical axis of the lens intersects with the primary optical axis of the second transmission reflection element on a specular reflection surface of the first transmission reflection element; and
an included angle between the specular reflection surface of the first transmission reflection element and the first direction is equal to 45 degrees.

7. The optical device according to claim 3 , wherein the first transmission reflection element is a polarization beam splitting element.

8. The optical device according to claim 7 , further comprising a quarter-wave plate, wherein the quarter-wave plate is arranged between the first transmission reflection element and the second transmission reflection element in the second direction, and the light of the first image is sequentially reflected by the first transmission reflection element, transmitted by the quarter-wave plate, reflected by the second transmission reflection element, transmitted by the quarter-wave plate, and transmitted by the first transmission reflection element.

9. The optical device according to claim 8 , wherein the first direction is perpendicular to the second direction, and the second direction is perpendicular to the quarter-wave plate.

10. The optical device according to claim 8 , wherein an intersection of an extension line of the first transmission reflection element and an extension line of the second transmission reflection element is positioned in a plane where the quarter-wave plate is positioned.

11. The optical device according to claim 7 , further comprising:
a polarizer, which is positioned on a light incident side or a light emergent side of the lens in the first direction,
wherein the polarizer is configured to enable polarized light emerging from the polarizer to be s-polarized light; and
the polarization beam splitting element is configured to reflect the s-polarized light.

12. The optical device according to claim 3 , wherein reflectivity of the first transmission reflection element and reflectivity of the second transmission reflection element are greater than or equal to 50%.

13. The optical device according to claim 2 , wherein the first lens face is arranged between the second lens face and the micro-display in the first direction.

14. The optical device according to claim 13 , wherein both the first lens face and the second lens face are even-order aspheric surfaces;
a surface shape z of the first lens face of the lens meets an expression (1) as follows:

z
⁢
1

=

c
⁢
1
×
r
⁢

1
2

1
+

1
-

(

1
+

k
⁢
1

)

×
c
⁢
1
×
r
⁢

1
2

+

a
⁢
1
⁢
1
×
r
⁢

1
2

+

a
⁢
1
⁢
2
×
r
⁢

1
4

+

a
⁢
1
⁢
3

Assignees

• Beijing Boe Optoelectronics Tech Co Ltd
• Boe Technology Group Co Ltd

Inventors

• Dong Ruijun
• Liu Yali
• Wang Chenru
• Li Ke
• Zhang Hao

Classifications

• G02B2027/0178

  Eyeglass type (eyeglass details G02C) · CPC title

• G02B27/126

  The splitting element being a prism or prismatic array, including systems based on total internal reflection · CPC title

• G02B13/002 Primary

  having at least one aspherical surface · CPC title

• G02B3/04

  with continuous faces that are rotationally symmetrical but deviate from a true sphere {, e.g. so called "aspheric" lenses} · CPC title

• G02B27/283

  used for beam splitting or combining · CPC title