US 10,890,770 B2
Waveguide having partial reflector
Wanli Chi, Sammamish, WA (US); Matthieu Charles Raoul Leibovici, Seattle, WA (US); Austin Lane, Bellevue, WA (US); and Kavous Jorabchi, Bellevue, WA (US)
Assigned to FACEBOOK TECHNOLOGIES, LLC, Menlo Park, CA (US)
Filed by Facebook Technologies, LLC, Menlo Park, CA (US)
Filed on Nov. 15, 2018, as Appl. No. 16/192,474.
Prior Publication US 2020/0158928 A1, May 21, 2020
Int. Cl. G02B 27/01 (2006.01); G02B 5/18 (2006.01)
CPC G02B 27/0172 (2013.01) [G02B 5/1842 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A waveguide comprising:
a substrate comprising first and second outer surfaces for propagating a beam of image light in the substrate by reflecting the beam from the first and second surfaces;
a diffraction grating supported by the substrate and configured for diffracting the beam impinging thereon; and
a first partial reflector disposed in the substrate between and parallel to the first and second surfaces, wherein the first partial reflector is flat, extends across length and width of the substrate, and is configured for splitting the beam impinging thereon.