Compact eye-tracked head-mounted display
Eye-tracked head-mounted displays are provide which, in one aspect, may utilize the same optics for eyetracking and image viewing, with a selected portion of the optics used for an eyetracking optical path and a selected portion of the display optics used for an image viewing optical path.
1. An eye-tracked head-mounted display, comprising:
a micro-display for generating an image to be viewed by a user, the micro-display having a display optical path and an exit pupil associated therewith;
a first plane located at the micro-display and a second plane located at the exit pupil;
an image sensor configured to receive reflected optical radiation from the exit pupil reflected from a user's eye positioned thereat, the image sensor having a sensor optical path associated therewith;
display optics disposed in optical communication with the micro-display along the display optical path and in optical communication with the image sensor along the sensor optical path, the display optics having a selected surface, closest to the micro-display and the image sensor for receiving optical radiation from the micro-display; and
an illumination source disposed at a location proximate the micro-display and the selected surface to illuminate the selected surface with optical radiation from the illumination source without illuminating the micro-display, the display optics configured to transmit the optical radiation from the illumination source and from the micro-display therethrough from the selected surface to the exit pupil.
2. The eye-tracked head-mounted display according to claim 1 , wherein the display and image sensor optical paths partially overlap at the selected surface.
3. The eye-tracked head-mounted display according to claim 1 , wherein the display optics is configured to create a virtual image of the micro-display for viewing at the exit pupil.
4. The eye-tracked head-mounted display according to claim 1 , wherein the display optical path and sensor optical path each comprise respective optical axes at the micro-display and image sensor, respectively, and wherein the optical axes are parallel to one another.
5. The eye-tracked head-mounted display according to claim 1 , wherein the display optical path comprises an optical axis, and wherein the image sensor is located off the optical axis of the display optical path.
6. The eye-tracked head-mounted display according to claim 1 , wherein the display optical path comprises an optical axis, and wherein the image sensor is located on the optical axis of the display optical path.
7. The eye-tracked head-mounted display according to claim 1 , comprising a stop at the first plane, the stop having at least one aperture therein disposed at a location along the sensor optical path.
8. The eye-tracked head-mounted display according to claim 1 , comprising a stop having at least one aperture therein disposed at a location along the sensor optical path between the sensor and selected surface.
9. The eye-tracked head-mounted display according to claim 8 , wherein the at least one aperture comprises a pin-hole.
10. The eye-tracked head-mounted display according to claim 1 , wherein the display optics comprises a freeform optical element.
11. The eye-tracked head-mounted display according to claim 1 , wherein the display optics comprises a rotationally symmetric optical element.
12. The eye-tracked head-mounted display according to claim 1 , wherein the display optics comprises a freeform optical prism.
13. The eye-tracked head-mounted display according to claim 12 , wherein the prism comprises a wedge-shaped prism.
14. The eye-tracked head-mounted display according to claim 12 , wherein the prism comprises an aspheric surface.
15. The eye-tracked head-mounted display according to claim 12 , wherein the prism is telecentric in display space.
16. The eye-tracked head-mounted display according to claim 12 , wherein the prism is non-telecentric in display space.
17. The eye-tracked head-mounted display according to claim 12 , wherein the prism comprises a TIR (total internal reflection) surface oriented to receive and totally internally reflect light from the micro-display.
18. The eye-tracked head-mounted display according to claim 12 , wherein the prism comprises a TIR (total internal reflection) surface oriented to totally internally reflect light to the image sensor.
19. The eye-tracked head-mounted display according to claim 12 , comprising a freeform corrective lens in optical communication with the prism.
20. The eye-tracked head-mounted display according to claim 19 , wherein field of view of the corrective lens is larger than a field of view of the display optics.