US Patent 11307654 Ambient light eye illumination for eye-tracking in near-eye display

Techniques disclosed herein relate to eye illumination for eye tracking in a near-eye display system. One example of an eye illumination system includes a substrate transparent to visible light and infrared light and configured to be placed in front of an eye of a user, and a shortwave-pass filter on a first surface of the substrate. The shortwave-pass filter includes regions configured to transmit visible light and reflect infrared light in ambient light, and a plurality of windows configured to transmit both visible light and infrared light in the ambient light.