Illumination systems employing laminated sheet-form optical structures with embedded tir channels

Abstract

An illumination system comprising a lighting module with a plurality of LEDs, a flexible optically transmissive sheet disposed in an energy-receiving relationship with the lighting module, and broad-area reflective surface configured to reflectively scatter light. The flexible optically transmissive sheet has a laminated structure with a generally rectangular shape and a thickness between 200 micrometers and 1 millimeter. The laminated structure comprises a first layer of an optically transmissive material, a second layer of an optically transmissive material, a first regular array of linear channels formed in the first layer extending parallel to one another between two edges of the flexible optically transmissive sheet, and a second regular array of linear channels formed in the second layer extending at an angle with respect to the first regular array of linear channels. The linear channels define side walls configured to reflect light using total internal reflection.