Systems and methods for using a display as an illumination source for eye tracking
The disclosed eye-tracking systems may include a visible light display having visible light pixels, at least one infrared pixel positioned within bounds of the visible light display, and an infrared sensor positioned and configured to detect infrared light originating from the at least one infrared pixel and reflected from an eye of the user. Related head-mounted display systems and methods for eye tracking are also disclosed.
1. An eye-tracking system, comprising:
a visible light display configured to display visible images to an eye of a user via a plurality of visible light pixels;
a plurality of infrared pixels positioned to project a grid of infrared light invisible to the user from within bounds of the visible light display; and
an infrared sensor positioned and configured to detect infrared light originating from the plurality of infrared pixels and reflected from the eye of the user.
2. The eye-tracking system of claim 1 , wherein the plurality of infrared pixels are positioned laterally between visible light pixels of the visible light display.
3. The eye-tracking system of claim 1 , further comprising a frame supporting the visible light display.
4. The eye-tracking system of claim 3 , wherein the infrared sensor comprises a plurality of infrared sensor elements positioned on the frame.
5. The eye-tracking system of claim 3 , wherein the frame is a frame of an artificial-reality headset.
6. The eye-tracking system of claim 3 , further comprising an infrared source positioned on or in the frame.
7. The eye-tracking system of claim 1 , wherein each of the visible light pixels comprises at least one visible light source configured to emit red, green, and blue light.
8. The eye-tracking system of claim 1 , wherein the infrared pixels are configured to emit infrared light at alternating times relative to visible light emitted from the visible light pixels.
9. The eye-tracking system of claim 1 , wherein the visible light display comprises at least one waveguide for directing visible light and infrared light from at least one projector to the eye of the user.
10. The eye-tracking system of claim 1 , wherein the plurality of infrared pixels are at least one of:
interspersed among visible light pixels of the visible light display;
positioned in front of corresponding visible light pixels of the visible light display; or
positioned behind corresponding visible light pixels of the visible light display.
11. The eye-tracking system of claim 1 , wherein the grid of infrared light comprises a nonsymmetrical grid of infrared light.
12. The eye-tracking system of claim 1 , wherein the grid of infrared light is movable relative to the visible light display.
13. A head-mounted display system, comprising:
a head-mounted display comprising a visible light source including visible light pixels configured to be located centrally in front of a user's eye and for directing visible images to the user's eye when in use;
an infrared source positioned on or in the head-mounted display to be located centrally in front of the user's eye and for directing to the user's eye a grid of infrared light that is invisible to the user; and
an infrared sensor for detecting infrared light from the infrared source and reflected from the user's eye and for tracking a position of the user's eye.
14. The head-mounted display system of claim 13 , wherein the infrared source comprises a plurality of infrared pixels arranged in a static grid relative to the visible light source.
15. The head-mounted display system of claim 13 , wherein the infrared source comprises at least one of:
a plurality of infrared pixels interspersed among visible light pixels of the head-mounted display;
a plurality of infrared pixels positioned in front of corresponding visible light pixels of the head-mounted display; or
a plurality of infrared pixels positioned behind corresponding visible light pixels of the head-mounted display.
16. The head-mounted display system of claim 13 , wherein the infrared source is positioned and configured to direct infrared light to a retina of the user's eye, and wherein the infrared sensor is configured to detect infrared light reflected from the retina of the user's eye.
17. The head-mounted display system of claim 13 , wherein the infrared source comprises a modulated light source configured to emit infrared light in a predetermined waveform to facilitate distinction of the infrared light from the infrared source relative to environmental infrared light.
18. A method for eye tracking, comprising:
directing, with a plurality of visible light pixels of a visible light display, a visible image to an eye of a user;
directing, with infrared pixels positioned within bounds of the visible light display, a grid of infrared light that is invisible to the user to the eye of the user; and
detecting, with an infrared sensor, infrared light originating from the infrared pixels and reflected from the eye of the user.
19. The method of claim 18 , wherein detecting infrared light originating from the infrared pixels and reflected from the eye of the user comprises detecting infrared light reflected from a retina of the eye of the user.
20. The method of claim 18 , wherein directing the grid of infrared light comprises selectively activating the infrared pixels to produce an infrared light pattern that moves relative to the visible light display.