Dynamic control of waveguide eye box
One disclosed example provides a near-eye display device. The near-eye display device comprises an eye tracking system configured to determine a position of an eye of a user relative to the near-eye display device, and a waveguide including at least an input coupler and an output coupler, the output coupler including a plurality of zones, each zone activatable via a dynamically controllable output coupling element of the zone. The near-eye display device further comprises an image source configured to output image light to the input coupler, and a controller configured to selectively activate one or more zones of the output coupler based at least on the position of the eye.
1. A near-eye display device, comprising:
an eye tracking system configured to determine a position of an eye of a user relative to the near-eye display device;
a waveguide including at least an input coupler and an output coupler, the output coupler including a plurality of zones, each zone activatable via a dynamically controllable output coupling element of the zone;
an image source configured to output image light to the input coupler; and
a controller configured to selectively activate one or more zones of the output coupler based at least on the position of the eye.
2. The near-eye display device of claim 1 , wherein the image source is further configured to selectively illuminate zones that are switched on and not illuminate one or more other zones.
3. The near-eye display device of claim 1 , wherein the controller is further configured to sequentially activate zones to generate a single image frame at a pupil of the eye of the user.
4. The near-eye display device of claim 1 , wherein the controller is further configured to selectively adjust an output efficiency of each dynamically controllable output coupling element via duty cycle adjustment.
5. The near-eye display device of claim 1 , wherein the image source comprises a spatial light modulator or an emissive display panel.
6. The near-eye display device of claim 1 , wherein the image source comprises a scanning image source.
7. The near-eye display device of claim 1 , wherein each dynamically controllable output coupling element includes a switchable polarization grating.
8. The near-eye display device of claim 7 , wherein the switchable polarization grating comprises a switchable Bragg grating.
9. The near-eye display device of claim 1 , wherein each zone is biased to output light over a predetermined offset angle range.
10. The near-eye display device of claim 1 , wherein the dynamically controllable output coupling element includes a multiple order grating.
11. The near-eye display device of claim 1 , wherein at least some zones are biased not to output light in absence of a control signal.
12. A method for operating a near-eye display device, comprising:
receiving data indicating a position of an eye of a user relative to the near-eye display device;
sequentially outputting image light from two or more different portions of an image source to an input coupler of a waveguide; and
sequentially activating two or more zones of an output coupler of the waveguide in coordination with sequentially outputting the image light from the two or more different portions of the image source to direct the image light to an eye box, each zone of the output coupler comprising a dynamically controllable output coupling element.
13. The method of claim 12 , further comprising selectively adjusting an output efficiency of one or more zones via controlling a duty cycle of the dynamically controllable output coupling element in each of the one or more zones.
14. The method of claim 12 , wherein sequentially outputting the image light from the two or more different portions of the image source comprises outputting the image light from two or more different locations on a display panel.
15. The method of claim 12 , wherein sequentially outputting the image light from the two or more different portions of the image source comprises outputting the image light from two or more different raster scan portions.
16. The method of claim 12 , wherein sequentially activating the two or more zones comprises sequentially activating a switchable polarization grating in each zone of the two or more zones.
17. A near-eye display device, comprising:
an eye tracking system configured to determine a position of an eye of a user relative to the near-eye display device;
a waveguide including a grating, the grating including a plurality of dynamically controllable diffractive zones to selectively diffract light toward a corresponding location of an output coupler for emission;
an image source configured to output image light to the input coupler; and
a controller configured to selectively activate one or more zones of the grating based at least on the position of the eye.
18. The near-eye display device of claim 17 , wherein the grating comprises a turning grating.
19. The near-eye display device of claim 17 , wherein each dynamically controllable diffractive zone comprises a switchable polarization grating.
20. The near-eye display device of claim 17 , wherein the output coupler further comprises a plurality of dynamically controllable output coupling elements.