Patent ID: 11194085

Abstract:
An illumination system with enhanced light coupling employing an optical waveguide and a linear array of discrete side-emitting light emitting diode (LED) packages which provide a light source. The optical waveguide is formed from a thin and flexible light transmissive sheet having a thickness between 0.2 mm and 2 mm and including a light input edge, a patterned light extraction area located at a distance from the light input edge, and a light mixing area located between the light input edge and the light extraction area. The LEDs are arranged on a flexible printed circuit board (PCB) which is positioned parallel to the light transmissive sheet and has a substantial portion of its area disposed in a space between the light input edge and an opposite edge. The light mixing area may include one or more light coupling structures and the flexible PCB may be bonded to the optical waveguide using adhesive. Light emitted by the LEDs is mixed within the light mixing area, distributed over the waveguiding substrate and emitted from the light extraction area.