US 11,835,728 B2
Eye tracking system
Fenglin Peng, Redmond, WA (US); Ying Geng, Bellevue, WA (US); and Oleg Yaroshchuk, Redmond, WA (US)
Assigned to Meta Platforms Technologies, LLC, Menlo Park, CA (US)
Filed by Meta Platforms Technologies, LLC, Menlo Park, CA (US)
Filed on May 11, 2020, as Appl. No. 16/872,109.
Prior Publication US 2021/0349327 A1, Nov. 11, 2021
Int. Cl. G02B 27/28 (2006.01); G02B 27/01 (2006.01); G02B 27/42 (2006.01)
CPC G02B 27/283 (2013.01) [G02B 27/0172 (2013.01); G02B 27/0179 (2013.01); G02B 27/425 (2013.01); G02B 2027/0178 (2013.01); G02B 2027/0187 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An eye-tracking optical assembly comprising:
a light source for illuminating an eye;
a first diffraction type polarizing beam splitter (DT-PBS); and
a second DT-PBS, wherein the first DT-PBS is configured to direct, based on polarization, a first portion of light from the second DT-PBS towards an eye-tracking detector,
wherein one of the first DT-PBS and the second DT-PBS is configured to compensate for a spectral dispersion of one other of the first DT-PBS and the second DT-PBS.