Patent ID: 8092064

Claim:
An illumination assembly comprising: a plurality of illumination tiles, each illumination tile comprising a light guide in which light propagates by total internal reflection, a light emission surface and a plurality of light extracting features varying in number per unit area along the length of the light guide, wherein the plurality of illumination tiles are arranged in a two-dimensional array, the illumination tiles being constructed and arranged so as to provide a substantially contiguous illumination surface comprising the light emission surfaces of each light guide, and each tile optically isolated from the other tiles to prevent light from coupling to each adjacent tile; alignment members configured to align the plurality of illumination tiles in the two-dimensional array, wherein the alignment members are physically separate from the illumination tiles; and a plurality of solid state light-emitting devices, wherein each illumination tile is illuminated by at least one of the solid state light-emitting devices; and wherein the illumination assembly is a backlight for a video display in which each illumination tile outputs light from the emission surface to provide light to a corresponding group of pixel light valves of the video display, an illumination output of each illumination tile independently controlled for local dimming of the video display according to brightness values in a video signal applied to the video display for the corresponding group of pixel light valves and the illumination output updated for each frame of the video signal.