US 12,256,153 B1
Polarization volume hologram combiner enabling wide population coverage, eye tracking accuracy, and glint generation
Yun-Han Lee, Redmond, WA (US); Matthieu Charles Raoul Leibovici, Seattle, WA (US); Chulwoo Oh, Sammamish, WA (US); Hyunmin Song, Redmond, WA (US); and Junren Wang, Kirkland, WA (US)
Assigned to META PLATFORMS TECHNOLOGIES, LLC, Menlo Park, CA (US)
Filed by META PLATFORMS TECHNOLOGIES, LLC, Menlo Park, CA (US)
Filed on Oct. 19, 2022, as Appl. No. 17/969,605.
Claims priority of provisional application 63/394,864, filed on Aug. 3, 2022.
Int. Cl. H04N 23/74 (2023.01); G03H 1/02 (2006.01); G06F 3/01 (2006.01); H04N 23/56 (2023.01)
CPC H04N 23/74 (2023.01) [G03H 1/0248 (2013.01); G06F 3/013 (2013.01); H04N 23/56 (2023.01); G03H 2260/33 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An eye tracking system, comprising:
one or more illumination sources;
one or more imaging devices; and
a polarization volume hologram (PVH) combiner that comprises a liquid crystal (LC) layer having a non-uniform chiral concentration, a non-uniform rotating power, and a non-uniform helical pitch across a plurality of regions of a surface of the PVH combiner,
wherein the PVH combiner is configured to direct light from the one or more illumination sources to a user's eye, direct light from the user's eye to the one or more imaging devices, or a combination thereof.