US 11,835,729 B2
Illumination 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 Oct. 24, 2022, as Appl. No. 18/049,173.
Application 18/049,173 is a continuation of application No. 16/872,101, filed on May 11, 2020, granted, now 11,513,362.
Prior Publication US 2023/0060915 A1, Mar. 2, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. G02B 27/28 (2006.01); G02B 27/01 (2006.01); G02B 27/42 (2006.01); G02F 1/1362 (2006.01); G02B 27/00 (2006.01); G02F 1/1335 (2006.01); G02B 5/30 (2006.01)
CPC G02B 27/283 (2013.01) [G02B 27/0172 (2013.01); G02B 27/425 (2013.01); G02F 1/136277 (2013.01); G02B 2027/0178 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An optical assembly comprising:
a light source for illuminating a display; and
a diffraction type polarizing beam splitter (DT-PBS) configured to direct light from a light director, wherein the DT-PBS is polarization sensitive and configured to direct, based on polarization, a first portion of light towards the display,
wherein at least one of the DT-PBS and the light director comprise one of a reflective polarization volume grating, a transmissive polarization volume grating, a Pancharatnam-Berry Phase (PBP) grating, a liquid crystal filled surface relief grating, or a holographic polymer dispersed liquid crystal grating.