Light guide and near-eye display apparatus

Patent metadata

Field	Value
Publication number	US-12379599-B2
Application number	US-202318508930-A
Country	US
Kind code	B2
Filing date	Nov 14, 2023
Priority date	May 19, 2021
Publication date	Aug 5, 2025
Grant date	Aug 5, 2025

Abstract

The present disclosure relates to light guides and near-eye display apparatuses. One example light guide includes a light guide plate and a two-dimensional grating that is disposed on a surface of the light guide plate. The two-dimensional grating includes a plurality of grating units arranged in a planar shape, the grating units are arranged at an interval of a first distance along a first direction and at an interval of a second distance along a second direction, and the first direction intersects with the second direction. The two-dimensional grating includes a light egress area and a light ingress area that are arranged along a third direction, and a fourth direction is perpendicular to the third direction.

First claim

What is claimed is:

1. A near-eye display apparatus, comprising:
a housing;
an optical receiver/transmitter; and
a light guide, wherein:
the optical receiver/transmitter and the light guide are disposed at the housing, and the optical receiver/transmitter is configured to generate a light ray and emit the light ray to a light ingress area of the light guide;
the light guide comprises a light guide plate and a two-dimensional grating that is disposed on a first surface of the light guide plate, the first surface is closer to an eye than a second surface of the light guide plate when the near-eye display apparatus is worn, the two-dimensional grating comprises a plurality of grating units, the plurality of grating units are arranged at an interval of a first distance along a first direction and are arranged at an interval of a second distance along a second direction, and the first direction intersects with the second direction;
the two-dimensional grating comprises a light egress area and a light ingress area that are arranged along a third direction, wherein a fourth direction is perpendicular to the third direction, wherein the first direction, the second direction, the third direction, and the fourth direction are located on a same plane, and wherein any two directions of the first direction, the second direction, the third direction, and the fourth direction do not overlap; and
each grating unit of the plurality of grating units is configured to diffract one incident light beam into at least three emergent light beams, wherein the grating unit is configured to generate a first grating vector, a second grating vector, and a plurality of combined grating vectors, wherein the first grating vector is perpendicular to the first direction, the second grating vector is perpendicular to the second direction, a combined grating vector is a vector sum of the first grating vector at a diffraction order M1 and the second grating vector at a diffraction order M2, and M1 and M2 are integers.

2. The near-eye display apparatus according to claim 1 , wherein the first direction and the second direction are symmetric relative to the third direction.

3. The near-eye display apparatus according to claim 1 , wherein the two-dimensional grating comprises at least two sub-areas, and grating units in neighboring sub-areas have different forms.

4. The near-eye display apparatus according to claim 1 , wherein the plurality of grating units of the two-dimensional grating have a same form.

5. The near-eye display apparatus according to claim 1 , wherein an included acute angle between the first direction and the fourth direction is between 10° and 80°, and an included acute angle between the second direction and the fourth direction is between 10° and 80°.

6. The near-eye display apparatus according to claim 1 , wherein a field of view of a picture transmitted by the light guide is at least 60°.

7. The near-eye display apparatus according to claim 1 , wherein the optical receiver/transmitter comprises a liquid crystal on silicon (LCOS) optical receiver/transmitter or a digital light processing optical receiver/transmitter.

8. The near-eye display apparatus according to claim 1 , wherein the light ray generated by the optical receiver/transmitter comprises red light, green light, and blue light.

9. The near-eye display apparatus according to claim 1 , wherein the two-dimensional grating comprises at least two sub-areas, first distances of neighboring sub-areas are different, and second distances of the neighboring sub-areas are different.

10. The near-eye display apparatus according to claim 9 , wherein the two-dimensional grating comprises a first sub-area and a second sub-area, the light ingress area and the light egress area are located in the first sub-area, the second sub-area is located on a side that is of the light egress area and that is away from the light ingress area, the first distance of the first sub-area is greater than the first distance of the second sub-area, and the second distance of the first sub-area is greater than the second distance of the second sub-area.

11. The near-eye display apparatus according to claim 9 , wherein the first distance is between 200 nm and 600 nm, and the second distance is between 200 nm and 600 nm.

12. The near-eye display apparatus according to claim 1 , wherein:
a grating unit in the light ingress area is configured to receive a light ray, and after being expanded inside the light guide plate by the grating unit in the light ingress area, the light ray is emitted out of a grating unit in the light egress area; and
after being emitted to the grating unit in the light ingress area, the light ray is transmitted under the effect of the first grating vector, the second grating vector, and the combined grating vector, and a vector sum of grating vectors of the light ray during the transmission is zero.

13. The near-eye display apparatus according to claim 12 , wherein the diffraction order M1 comprises −3, −2, −1, 0, 1, 2, and 3, and the diffraction order M2 comprises −3, −2, −1, 0, 1, 2, and 3.

14. The near-eye display apparatus according to claim 1 , wherein the near-eye display apparatus comprises virtual reality glasses or augmented reality glasses.

15. The near-eye display apparatus according to claim 14 , wherein the optical receiver/transmitter comprises a laser, a scanner, and a controller, and the scanner is configured to:
scan an incident ray emitted by the laser; and
send the incident ray to the light guide.

16. A light guide, comprising:
a light guide plate; and
a two-dimensional grating that is disposed on a first surface of the light guide plate, wherein:
the first surface is closer to an eye than a second surface of the light guide plate when the light guide is in use, the two-dimensional grating comprises a plurality of grating units, the plurality of grating units are arranged at an interval of a first distance along a first direction and are arranged at an interval of a second distance along a second direction, and the first direction intersects with the second direction;
the two-dimensional grating comprises a light egress area and a light ingress area that are arranged along a third direction, a fourth direction is perpendicular to the third direction, the first direction, the second direction, the third direction, and the fourth direction are located on a same plane, and any two directions of the first direction, the second direction, the third direction, and the fourth direction do not overlap; and
each grating unit of the plurality of grating units is configured to diffract one incident light beam into at least three emergent light beams, wherein the grating unit is configured to generate a first grating vector, a second grating vector, and a plurality of combined grating vectors, wherein the first grating vector is perpendicular to the first direction, the second grating vector is perpendicular to the second direction, a combined grating vector is a vector sum of the first grating vector at a diffraction order M1 and the second grating vector at a diffraction order M2, and M1 and M2 are integers.

17. The light guide according to claim 16 , wherein the first direction and the second direction are symmetric relative to the third direction.

18. The light guide according to claim 16 , wherein the two-dimensional grating comprises at least two sub-areas, and grating units in neighboring sub-areas have different forms.

19. The light guide according to claim 16 , wherein the plurality of gra

Assignees

• Huawei Tech Co Ltd

Inventors

• Zhou Haifeng
• Liu Liming
• Ding ziqian

Classifications

• G02B2027/0178

  Eyeglass type (eyeglass details G02C) · CPC title

• G02B6/0036

  2-D arrangement of prisms, protrusions, indentations or roughened surfaces · CPC title

• G02B6/0016 Primary

  Grooves, prisms, gratings, scattering particles or rough surfaces · CPC title

• G02B27/4205

  having a diffractive optical element [DOE] contributing to image formation, e.g. whereby modulation transfer function MTF or optical aberrations are relevant · CPC title

• G02B27/0172 Primary

  characterised by optical features · CPC title