Patent ID: 11860358
Assignee: META PLATFORMS TECHNOLOGIES, LLC
Field: Optics (Instruments)
Classification: CPC G | IPC G

Claim 8:
9. A head mounted device comprising:
a frame for securing the head mounted device on a head of a user; and
an eye-tracking system including:
a plurality of infrared light sources configured to emit infrared illumination light to an eyebox region; and
a plurality of angular light sensors configured to receive returning infrared light that is the infrared illumination light reflecting from the eyebox region, wherein the angular light sensors in the plurality are configured to output angular signals representing an angle of incidence of the returning infrared light with respect to positions of the angular light sensors, wherein the angular light sensors include:

a first photodiode configured to receive the returning infrared light;
a second photodiode configured to receive the returning infrared light; and
a tilted light barrier disposed between the first photodiode and the second photodiode, the tilted light barrier being angled with respect to a surface-normal of a sensing plane common to both the first photodiode and the second photodiode, wherein a ratio of a first signal generated by the first photodiode and a second signal generated by the second photodiode indicates the angle of incidence of the returning infrared light.