Patent ID: 8979349
Filing Date: 2015-03-17
Classification: G02B,G02F

Abstract:
1. An illumination apparatus comprising: a light source; a light guide having a generally planar first surface, a generally planar second surface opposite the first surface, a first end and a second end, and a length therebetween, wherein the light guide is positioned to receive light from the light source into the light guide first end, and wherein the light guide is configured such that light from the light source provided into the first end of the light guide propagates generally towards the second end; and a plurality of light turning features, each light turning feature having a turning surface configured to receive at least a portion of the light which is propagating generally towards the second end of the light guide and reflect at least a portion of the received light out of the first surface of the light guide, each light turning feature including an interferometric stack formed on at least a portion of the turning surface; wherein each light turning feature includes a depression formed in the first surface or the second surface of the light guide.