US 12,216,284 B2
Optical system with compact coupling from a projector into a waveguide
Ronen Chriki, Lod (IL); Tsion Eisenfeld, Ashkelon (IL); and Elad Sharlin, Mishmar David (IL)
Assigned to LUMUS LTD., Ness Ziona (IL)
Filed by Lumus Ltd., Ness Ziona (IL)
Filed on Dec. 20, 2023, as Appl. No. 18/390,074.
Application 18/390,074 is a continuation of application No. 18/039,260, previously published as PCT/IL2022/050226, filed on Mar. 1, 2022.
Claims priority of provisional application 63/154,870, filed on Mar. 1, 2021.
Prior Publication US 2024/0126085 A1, Apr. 18, 2024
Int. Cl. G02B 27/01 (2006.01); G02B 27/28 (2006.01)
CPC G02B 27/0172 (2013.01) [G02B 27/283 (2013.01)] 9 Claims
OG exemplary drawing
 
1. An optical system comprising:
(a) a light-guide optical element (LOE) formed from transparent material and having mutually-parallel first and second major external surfaces for guiding light by internal reflection;
(b) a projector configured to project light corresponding to a collimated image from an aperture, the light exiting said aperture with a chief ray defining an optical axis of said projector and with an angular field about the chief ray;
(c) a coupling-in arrangement associated with said projector and with said LOE for coupling said light from said projector into said LOE at a coupling-in region so that the light undergoes internal reflection at said major external surfaces, said coupling-in arrangement including a reflective polarizing beam splitter and a waveplate deployed such that, for at least one part of said angular field, the light propagating within said LOE has spatial non-uniformity of polarization;
(d) a coupling-out arrangement associated with said LOE for redirecting the light propagating within said LOE towards a viewer, said coupling-out arrangement being polarization-sensitive; and
(e) a non-uniformity mitigating element selected from the group consisting of: a retarder; a birefringent depolarizing element; and a partially-reflecting mixing element, said non-uniformity mitigating element being associated with said LOE and deployed to interact with the light propagating within said LOE between said coupling-in arrangement and said coupling-out arrangement to as to decrease a non-uniformity in the light redirected towards the viewer caused by said spatial non-uniformity of polarization.