US 12,135,445 B2
Method of fabricating a light-guide optical element
Elad Sharlin, Mishmar David (IL); and Dror Hermoni, Kibbutz Usha (IL)
Assigned to LUMUS LTD., Ness Ziona (IL)
Appl. No. 17/429,977
Filed by Lumus Ltd., Ness Ziona (IL)
PCT Filed Apr. 14, 2020, PCT No. PCT/IB2020/053492
§ 371(c)(1), (2) Date Aug. 11, 2021,
PCT Pub. No. WO2020/212835, PCT Pub. Date Oct. 22, 2020.
Claims priority of provisional application 62/833,808, filed on Apr. 15, 2019.
Prior Publication US 2022/0137274 A1, May 5, 2022
Int. Cl. G02B 5/28 (2006.01); B29D 11/00 (2006.01); G02B 27/01 (2006.01)
CPC G02B 5/285 (2013.01) [B29D 11/00663 (2013.01); B29D 11/00865 (2013.01); G02B 27/0172 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A method of fabricating a light-guide optical element having a plurality of partially reflecting surfaces comprising:
providing a plurality of transparent plates, each plate polished on two opposite surfaces such that said surfaces are parallel to each other;
coating a first of said surfaces of a subset of plates with a first coating;
coating a second of said surfaces of said subset of plates with a second coating;
bonding together the plurality of transparent plates to form a stack comprising an alternating arrangement of coated plates of the subset of plates and uncoated plates; and
cutting the stack along parallel planes obliquely angled to the faces of the transparent plates so as to form the light-guide optical element;
wherein the first coating is a partially reflective coating having a first set of mechanical properties, and the second coating is a partially reflective coating having a second set of mechanical properties substantially similar to the first set of mechanical properties.