US 12,262,154 B2
Reflective display comprising coupling lightguides folded at different fold angles
Anthony Nichol, Minneapolis, MN (US); and Zane Coleman, Elmhurst, IL (US)
Assigned to Azumo, Inc., Chicago, IL (US)
Filed by AZUMO, INC., Chicago, IL (US)
Filed on Jul. 8, 2021, as Appl. No. 17/305,458.
Application 17/305,458 is a continuation of application No. PCT/US2020/012977, filed on Jan. 9, 2020.
Claims priority of provisional application 62/790,105, filed on Jan. 9, 2019.
Prior Publication US 2021/0337173 A1, Oct. 28, 2021
Int. Cl. H04N 9/31 (2006.01); F21V 8/00 (2006.01)
CPC H04N 9/3152 (2013.01) [G02B 6/0055 (2013.01); G02B 6/0076 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A display comprising:
a reflective spatial light modulator comprising a front viewing side and a back side opposite the front viewing side;
a lightguide formed from a film having opposing surfaces with a thickness not greater than 0.5 millimeters therebetween, the lightguide positioned on the front viewing side of the reflective spatial light modulator and comprising a lightguide region, a light emitting region, and a plurality of coupling lightguides in a form of strips of the film extending from and continuous with the lightguide region, and each coupling lightguide of the plurality of coupling lightguides terminates in a bounding edge;
a light source positioned to emit light into the bounding edges, the light propagating within the plurality of coupling lightguides to the lightguide region; and
a plurality of light extraction features arranged within the light emitting region, the plurality of light extraction features frustrate totally internally reflected light from the light source propagating in the lightguide region such that light exits the lightguide in the light emitting region and propagates to the reflective spatial light modulator,
wherein the plurality of coupling lightguides are folded along linear fold lines behind the reflective spatial light modulator such that the plurality of coupling lightguides are stacked on the back side of the reflective spatial light modulator with the bounding edges positioned to receive the light from the light source, and the linear fold lines of the plurality of coupling lightguides are oriented at different fold angles such that a difference between fold angles of adjacent coupling lightguides of the plurality of coupling lightguides is greater than 5 degrees.