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 illumination optics for used with a micro-display, comprising: an illumination source; a wedge-shaped freeform prism lens mounted with the illumination source and having a first surface configured to receive light from the illumination source and configured to transmit the received light into the body of the prism lens without illuminating the micro-display, a second surface configured to receive the light transmitted into the body of the prism lens from the first surface and configured to totally internally reflect the received light at the second surface, and a third surface configured to receive the light reflected by the second surface and configured to reflect the light out of the prism lens, at least one of the first, second and third surfaces having a freeform shape, the wedge-shaped freeform prism lens configured to transmit the optical radiation from the illumination source therethrough to an exit pupil; and an eyetracking sensor having a sensor optical path associated therewith that extends through the wedge-shaped freeform prism lens from the exit pupil to the sensor, the sensor located proximate the first surface of the wedge-shaped freeform prism lens to receive optical radiation reflected from a user's eye positioned at the exit pupil and transmitted through the prism lens along the sensor optical path to the sensor, the sensor optically conjugate to the exit pupil across the prism lens.
2. 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 the first surface.
3. The eye-tracked head-mounted display according to claim 2 , wherein the at least one aperture comprises a pin-hole.
4. The eye-tracked head-mounted display according to claim 1 , wherein the prism lens comprises an aspheric surface.
5. The eye-tracked head-mounted display according to claim 1 , wherein the prism lens comprises a TIR (total internal reflection) surface oriented to receive and totally internally reflect light from the micro-display.
6. The eye-tracked head-mounted display according to claim 1 , comprising a freeform corrective lens in optical communication with the prism lens.