Holographic virtual reality display

Patent metadata

Field	Value
Publication number	US-12092820-B2
Application number	US-202117475081-A
Country	US
Kind code	B2
Filing date	Sep 14, 2021
Priority date	Apr 16, 2021
Publication date	Sep 17, 2024
Grant date	Sep 17, 2024

Abstract

Virtual reality (VR) displays are computer displays that present images or video in a manner that simulates a real experience for the viewer. In many cases, VR displays are implemented as head-mounted displays (HMDs) which provide a display in the line of sight of the user. Because current HMDs are composed of a display panel and magnifying lens with a gap therebetween, proper functioning of the HMDs limits their design to a box-like form factor, thereby negatively impacting both comfort and aesthetics. The present disclosure provides a different configuration for a virtual reality display which allows for improved comfort and aesthetics, including specifically at least one coherent light source, at least one holographic waveguide coupled to the at least one coherent light source to receive light therefrom, and at least one spatial light modulator coupled to the at least one holographic waveguide to modulate the light.

First claim

What is claimed is:

1. An apparatus, comprising:
a virtual reality (VR) display, including:
at least one coherent light source,
at least one holographic waveguide coupled to the at least one coherent light source to receive light therefrom, and
at least one spatial light modulator coupled to the at least one holographic waveguide to modulate the light;
wherein the coherent light source includes a point light source that emits the light, a concave mirror that reflects the light emitted by the point light source, and a beam splitter that directs the light reflected by the concave mirror to the holographic waveguide;

wherein a phase and amplitude to be used by the spatial light modulator is determined based on a simulation where:
a complex wavefront at the spatial light modulator is simulated using an input phase and an input amplitude,
the input phase and the input amplitude are transformed to move to a frequency domain of the spatial light modulator,
the frequency domain is repeated to produce a plurality of higher order copies of the input phase and the input amplitude in the frequency domain,
the plurality of higher order copies of the input phase and the input amplitude are multiplied by an angular spectrum method (ASM) phase delay and a two-dimensional (2D) sinc amplitude that accounts for a finite pixel pitch of the spatial light modulator, to result in a propagation amplitude and propagation phase in the frequency domain, and
the propagation amplitude and propagation phase in the frequency domain are converted back from the frequency domain to produce the phase and the amplitude to be used by the spatial light modulator.

2. The apparatus of claim 1 , wherein the VR display further includes at least one magnifying lens.

3. The apparatus of claim 2 , wherein the at least one magnifying lens includes a Fresnel lens.

4. The apparatus of claim 2 , wherein the at least one magnifying lens includes a holographic lens.

5. The apparatus of claim 2 , wherein the VR display further includes at least one polarization element coupled between the at least one magnifying lens and the at least one holographic waveguide.

6. The apparatus of claim 1 , wherein the VR display further includes at least one quarter-wave element coupled between the at least one holographic waveguide and the at least one spatial light modulator.

7. The apparatus of claim 1 , wherein the at least one holographic waveguide includes a backlight holographic waveguide.

8. The apparatus of claim 1 , wherein the at least one holographic waveguide includes a holographic waveguide with at least one waveguide coupler.

9. The apparatus of claim 1 , wherein the at least one holographic waveguide includes a holographic waveguide including a waveguide in-coupler, and a waveguide out-coupler.

10. The apparatus of claim 1 , wherein the apparatus is configured such that the light is polarized.

11. The apparatus of claim 1 , wherein a combined cross-sectional thickness of the at least one holographic waveguide and the at least one spatial light modulator, is less than 10 mm.

12. The apparatus of claim 1 , wherein a combined cross-sectional thickness of the at least one holographic waveguide and the at least one spatial light modulator, is less than 7 mm.

13. The apparatus of claim 1 , wherein the VR display further includes a receiver for receiving pixel data from a remote source over a network, for display via the VR display.

14. The apparatus of claim 1 , wherein the VR display is filterless.

15. The apparatus of claim 1 , further comprising:
a geometric phase lens coupled to a first side of the holographic waveguide, and
a quarter wave plate coupled to a second side of the holographic waveguide with the spatial light modulator, wherein the quarter wave plate is coupled between the holographic waveguide and the spatial light modulator.

16. A method, comprising:
at head-mounted display including at least one coherent light source, at least one holographic waveguide coupled to the at least one coherent light source, and at least one spatial light modulator coupled to the at least one holographic waveguide such that a combined cross-sectional thickness of the at least one holographic waveguide and the at least one spatial light modulator is less than 10 mm, and wherein the coherent light source includes a point light source that emits the light, a concave mirror that reflects the light emitted by the point light source, and a beam splitter that directs the light reflected by the concave mirror to the holographic waveguide:
receiving, by the at least one holographic waveguide, light from the at least one coherent light source;
transmitting the light from the at least one holographic waveguide to the at least one spatial light modulator; and
modulating the light, utilizing the at least one spatial light modulator;
wherein a phase and amplitude to be used by the spatial light modulator is determined based on a simulation where:
a complex wavefront at the spatial light modulator is simulated using an input phase and an input amplitude,
the input phase and the input amplitude are transformed to move to a frequency domain of the spatial light modulator,
the frequency domain is repeated to produce a plurality of higher order copies of the input phase and the input amplitude in the frequency domain,
the plurality of higher order copies of the input phase and the input amplitude are multiplied by an angular spectrum method (ASM) phase delay and a two-dimensional (2D) sinc amplitude that accounts for a finite pixel pitch of the spatial light modulator, to result in a propagation amplitude and propagation phase in the frequency domain, and
the propagation amplitude and propagation phase in the frequency domain are converted back from the frequency domain to produce the phase and the amplitude to be used by the spatial light modulator.

17. The method of claim 16 , wherein the head-mounted display further includes at least one magnifying lens, and the method further comprising:
transmitting the modulated light through the at least one magnifying lens.

18. The method of claim 17 , wherein the at least one magnifying lens includes a Fresnel lens.

19. The method of claim 17 , wherein the at least one magnifying lens includes a holographic lens.

20. The method of claim 17 , wherein the head-mounted display further includes at least one polarization element coupled between the at least one magnifying lens and the at least one holographic waveguide, and the method further comprising:
polarizing the modulated light utilizing the at least one polarization element,
wherein the polarized modulated light is transmitted through the at least one magnifying lens.

21. The method of claim 16 , wherein the head-mounted display further includes at least one quarter-wave element coupled between the at least one holographic waveguide and the at least one spatial light modulator, and the method further comprising:
modifying the light from the at least one holographic waveguide, utilizing the at least one quarter-wave element,
wherein the modified light is received by the at least one spatial light modulator.

22. The method of claim 16 , wherein the at least one holographic waveguide includes a backlight holographic waveguide.

23. The method of claim 16 , wherein the at least one holographic waveguide includes a holographic waveguide with at least one waveguide coupler.

24. The method of

Assignees

• Nvidia Corp

Inventors

• Kim Jonghyun
• Lopes Ward
• Luebke David
• Gopakumar Manu

Classifications

• G06T19/006

  Mixed reality (object pose determination, tracking or camera calibration for mixed reality G06T7/00) · CPC title

• G06F3/013 Primary

  Eye tracking input arrangements (G06F3/015 takes precedence) · CPC title

• G03H2223/22

  Polariser · CPC title

• G03H2223/19

  Microoptic array, e.g. lens array · CPC title

• G03H2223/16

  Optical waveguide, e.g. optical fibre, rod · CPC title