US 11,914,187 B2
Image waveguide with symmetric beam multiplication
Eitan Ronen, Rechovot (IL); Ronen Chriki, Lod (IL); and Daniel Michaels, Ramat Gan (IL)
Assigned to LUMUS LTD., Ness Ziona (IL)
Appl. No. 17/420,675
Filed by Lumus Ltd., Ness Ziona (IL)
PCT Filed Jul. 5, 2020, PCT No. PCT/IL2020/050753
§ 371(c)(1), (2) Date Jul. 4, 2021,
PCT Pub. No. WO2021/001841, PCT Pub. Date Jan. 7, 2021.
Claims priority of provisional application 62/870,699, filed on Jul. 4, 2019.
Prior Publication US 2022/0099885 A1, Mar. 31, 2022
Int. Cl. G02B 6/10 (2006.01); G02B 27/01 (2006.01)
CPC G02B 6/10 (2013.01) [G02B 27/0172 (2013.01); G02B 2027/0178 (2013.01)] 4 Claims
OG exemplary drawing
 
1. An optical system for displaying an image to an eye of a user comprising:
(a) a light-guide optical element, LOE having two planar major external surfaces that are parallel so as to support propagation of image illumination within the LOE by internal reflection at the major external surfaces:
(b) a coupling-out configuration deployed at a coupling-out region of the LOE and configured for coupling out at least part of the image illumination from the LOE (towards the eye of the user; and
(c) an image projector for generating image illumination corresponding to a collimated image, the image projector being optically coupled to the LOE so as to introduce the image illumination into the LOE so as to propagate within the LOE by internal reflection, characterized in that the LOE further comprises a beam multiplier region, distinct from the coupling-out region, the beam multiplier region having n internal planar beam splitters, where n is an integer greater than 1, each beam splitter being internal to the LOE and parallel to the major external surfaces, the n beam splitters subdividing a thickness of the LOE between the major external surfaces into (n+1) layers of equal thickness, each beam splitter having a reflectivity for image illumination propagating within the LOE by internal reflection given by 1/(i+1) where i is an index for sequential beam splitters for i from 1 to n.