Waveguide with anti-reflection properties

Patent metadata

Field	Value
Publication number	US-12276792-B2
Application number	US-202217854825-A
Country	US
Kind code	B2
Filing date	Jun 30, 2022
Priority date	Jul 1, 2021
Publication date	Apr 15, 2025
Grant date	Apr 15, 2025

Abstract

A head-mounted display (HMD) system includes a lens element supported by a support structure. The lens element includes a waveguide that includes an incoupler, an outcoupler, and an exit pupil expander. The incoupler is disposed within a first area of the waveguide. The outcoupler is disposed within a second area of the waveguide. The exit pupil expander is disposed within a third area of the waveguide. An anti-reflection coating is formed via fabrication used to form the incoupler, the outcoupler, and the exit pupil expander. The anti-reflection coating is disposed within a fourth area of the waveguide different than the first, second, and third areas of the waveguide.

First claim

What is claimed is:

1. A system comprising:
a waveguide to couple light from an image source, the waveguide comprising:
an incoupler disposed within a first area of the waveguide;
an outcoupler disposed within a second area of the waveguide;
an exit pupil expander disposed within a third area of the waveguide; and
an anti-reflection coating disposed within a fourth area of the waveguide different than the first, second, and third areas of the waveguide,
wherein the incoupler, the outcoupler, the exit pupil expander, and the anti-reflection coating are located on a first side of the waveguide and the first area, the second area, and the third area are substantially free of the anti-reflection coating.

2. The system of claim 1 , wherein the anti-reflection coating is selectively disposed in an area between the exit pupil expander and the outcoupler.

3. The system of claim 1 , wherein the anti-reflection coating coats areas of the first side of the waveguide outside of the first area, the second area, and the third area.

4. The system of claim 1 , wherein the first area, the second area, and the third area are substantially surrounded by the fourth area.

5. The system of claim 1 , wherein the incoupler, the outcoupler, and the exit pupil expander include gratings that act as a quarterwave stack.

6. The system of claim 1 , wherein the anti-reflection coating is a first anti-reflection coating, the system further comprising a substrate and a second anti-reflection coating disposed on an opposite side of the substrate from the first anti-reflection coating.

7. A head-mounted display (HMD) system comprising:
a lens element supported by a support structure, the lens element including a waveguide, the waveguide comprising:
an incoupler;
an outcoupler;
an exit pupil expander; and
an anti-reflection coating selectively disposed in an area between the exit pupil expander and the outcoupler, wherein the exit pupil expander and the outcoupler are substantially free from the anti-reflection coating.

8. The HMD of claim 7 , wherein the anti-reflection coating, the exit pupil expander, and the outcoupler are located on a first side of the waveguide.

9. The HMD of claim 8 , wherein the anti-reflection coating coats areas of the first side of the waveguide outside of any areas where the incoupler, the outcoupler, and the exit pupil expander are deposited.

10. The HMD of claim 8 , wherein the incoupler, the outcoupler, and the exit pupil expander are substantially surrounded by the anti-reflection coating on the first side of the waveguide.

11. The HMD of claim 7 , wherein the incoupler, the outcoupler, and the exit pupil expander include gratings that act as a quarterwave stack.

12. The HMD of claim 7 , wherein the anti-reflection coating is a first anti-reflection coating, the system further comprising a substrate and a second anti-reflection coating disposed on an opposite side of the substrate from the first anti-reflection coating.

13. A method comprising:
disposing an incoupler within a first area of a waveguide;
disposing an outcoupler within a second area of the waveguide;
disposing an exit pupil expander within a third area of the waveguide; and
disposing an anti-reflection coating within a fourth area of the waveguide different than the first, second, and third areas of the waveguide, wherein the first area, the second area, and the third area are substantially free of the anti-reflection coating.

14. The method of claim 13 , wherein the anti-reflection coating comprises a four-layer stack.

15. The method of claim 14 , wherein the four-layer stack comprises a low index material layer disposed between first and second high index material layers, the first high index material layer formed onto a substrate layer.

16. The method of claim 15 , wherein the first high index material layer is thicker than the low index material layer, and the second high index material layer is thicker than the first high index material layer.

17. The method of claim 15 , wherein the low index material layer is a first low index material layer, and a second low index material layer is disposed onto the second high index material.

18. The method of claim 13 , wherein the incoupler, the outcoupler, and the exit pupil expander include gratings that act as a quarterwave stack.

Assignees

• Google Llc

Inventors

• Haque Syed Moez
• Potnis Shreyas
• Karbasi Ali
• Bodiya Timothy Paul
• Adema Daniel
• Andrews Ian

Classifications

• G02B2027/0125

  Field-of-view increase by wavefront division · CPC title

• G02B1/115

  Multilayers · CPC title

• G02B6/4206

  Optical features (G02B6/4207, G02B6/421 take precedence) · CPC title

• G02B6/4209

  Optical features · CPC title

• G02B27/0172 Primary

  characterised by optical features · CPC title