Patent ID: 9664839
Date: 2017-05-30
CPC Classifications: F21K,F21S,F21V,F21Y,G02B

Claim:
1. An illumination device comprising: a plurality of light-emitting elements (LEEs); one or more optical couplers, wherein the light provided by the LEEs is in an emission angular range; a light guide extending in a forward direction from a first end of the light guide to a second end of the light guide, wherein the optical couplers are arranged to receive the light provided by the LEEs and redirect it to the first end of the light guide where it has a collimated angular range when it is received by the light guide, and wherein the light guide is configured to guide the received light to the second end; an optical extractor optically coupled to the light guide at the second end to receive the guided light, the optical extractor comprising a redirecting surface to reflect a first portion of the guided light, wherein the reflected light is output by the optical extractor to the ambient environment in a backward angular range, and wherein the redirecting surface has one or more transmissive portions to transmit a second portion of the guided light in the forward direction; and one or more optical elements optically coupled to the one or more transmissive portions of the redirecting surface, the one or more optical elements to modify the light transmitted through the transmissive portions and to output the modified light to the ambient environment in a forward angular range.