Pupil-expanding display device

Patent metadata

Field	Value
Publication number	US-11137602-B2
Application number	US-201815963769-A
Country	US
Kind code	B2
Filing date	Apr 26, 2018
Priority date	Dec 29, 2017
Publication date	Oct 5, 2021
Grant date	Oct 5, 2021

Abstract

Examples are disclosed that relate to a display device. One example provides a display device comprising a projector and a pre-expander optic configured to replicate an exit pupil of the projector in at least a first direction, the pre-expander optic comprising a plurality of spectrally-selective pupil-replicating elements to form at least two exit pupils at different spatial locations, each exit pupil being for a different spectral band. The display device further comprises a waveguide comprising at least two incoupling pupils, each incoupling pupil configured to receive light from a corresponding exit pupil of the pre-expander optic, and the waveguide configured to replicate each corresponding exit pupil in at least a second direction and output the light received toward an eyebox.

First claim

The invention claimed is:

1. A display device, comprising:
a projector;
a pre-expander optic configured to expand an exit pupil of the projector in at least a first direction, the pre-expander optic comprising a plurality of spectrally-selective elements to form at least two exit pupils at different spatial locations, each exit pupil being for a different spectral band; and
a waveguide comprising at least two incoupling pupils spatially separated along a plane of the waveguide, each incoupling pupil configured to receive light from a corresponding exit pupil of the pre-expander optic, and the waveguide configured to expand each corresponding exit pupil in at least a second direction and output the light received toward an eyebox.

2. The display device of claim 1 , wherein the plurality of spectrally-selective elements comprises one or more diffractive optical elements.

3. The display device of claim 1 , wherein the plurality of spectrally-selective elements comprises one or more refractive optical elements.

4. The display device of claim 1 , wherein the plurality of spectrally-selective elements comprises one or more reflective optical elements.

5. The display device of claim 1 , wherein the pre-expander optic is configured to expand the exit pupil of the projector via pupil replication.

6. The display device of claim 1 , wherein the projector comprises one or more of a liquid crystal on silicon display, an organic light emitting device, and a laser projector.

7. The display device of claim 1 , wherein the pre-expander optic is configured to form three exit pupils at three different spatial locations, and wherein the waveguide comprises three incoupling pupils.

8. The display device of claim 1 , wherein the pre-expander optic is configured to form two exit pupils at two different spatial locations, and wherein the waveguide comprises two incoupling pupils.

9. The display device of claim 1 , wherein the at least two incoupling pupils comprises a red-green pupil and a blue-green pupil.

10. The display device of claim 1 , wherein the display device comprises a head-mounted display.

11. The display device of claim 1 , wherein the waveguide comprises, for each exit pupil of the pre-expander optic, an expansion structure for replicating the exit pupil in at least the second direction.

12. The display device of claim 11 , wherein one or more of the expansion structures comprises a diffractive grating.

13. A method of displaying an image, the method comprising:
incoupling an exit pupil of a projector into a pre-expander optic configured to expand the exit pupil in at least a first direction;
forming, via a plurality of spectrally-selective pupil-replicating elements of the pre-expander optic, at least two exit pupils at different spatial locations on the pre-expander optic, each exit pupil being for a different spectral band;
for each exit pupil of the pre-expander optic, incoupling light received from the exit pupil of the pre-expander optic into a waveguide via an incoupling pupil corresponding to the exit pupil, the waveguide comprising at least two incoupling pupils spatially separated along a plane of the waveguide;
via the waveguide, expanding each exit pupil in at least a second direction; and
outputting the light received toward an eyebox.

14. The method of claim 13 , wherein forming the at least two exit pupils comprises forming the at least two exit pupils via a plurality of one or more of a diffractive optical element, a refractive optical element, and a reflective optical element.

15. The method of claim 13 , wherein expanding each exit pupil in at least the second direction comprises expanding each exit pupil via an expansion structure of the waveguide corresponding to the exit pupil.

16. The method of claim 13 , wherein expanding each exit pupil in at least the second direction comprises expanding via pupil replication.

17. A display device, comprising:
a projector;
a first waveguide configured to expand an exit pupil of the projector in at least a first direction, the first waveguide comprising a plurality of spectrally-selective elements configured to form at least two exit pupils at different spatial locations, each exit pupil being for a different spectral band; and
a second waveguide configured to output light from the projector toward an eyebox, the second waveguide comprising at least two incoupling pupils spatially separated along a plane of the second waveguide, each incoupling pupil configured to receive light from a corresponding exit pupil of the first waveguide, and the second waveguide also comprising, for each exit pupil of the first waveguide, an expansion structure configured to expand the exit pupil in at least a second direction.

18. The display device of claim 17 , wherein the at least two incoupling pupils of the second waveguide are configured to receive light from corresponding exit pupils of the first waveguide at different spatial locations on an input surface of the second waveguide.

19. The display device of claim 17 , wherein the first waveguide is configured to form two exit pupils at two different spatial locations, and wherein the second waveguide comprises two incoupling pupils.

20. The display device of claim 19 , wherein the two exit pupils of the first waveguide comprise a red-green exit pupil and a green-blue exit pupil.

Assignees

• Microsoft Technology Licensing Llc

Inventors

• Vallius Tuomas Heikki Sakari
• Wall Richard Andrew
• Reshidko Dmitry
• Hyvarinen Heikki Juhana

Classifications

• G02B2027/0123

  comprising devices increasing the field of view · CPC title

• G02B2027/0178

  Eyeglass type (eyeglass details G02C) · CPC title

• G02B2027/0125

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

• G02B2027/0174

  holographic · CPC title

• G02B27/0172 Primary

  characterised by optical features · CPC title