Abstract: A large, efficient, high power collimated backlight assembly has a highly reflective, substantially closed, thin rectangular light cavity containing highly reflective surfaces and one or more light sources. One of the large faces of the cavity is a light exit plate which contains a transmissive, light collimating structure. The cavity side of the collimating structure includes a highly reflective white planar structure containing an array of circular apertures with minimal sidewall absorption. The apertures are centered on the optical axis and located near the focal distance of a closely packed array of hemispherical or spherical lenses located on the outer surface of the collimating structure. Light rays are trapped between the highly reflective surfaces of the cavity, light sources, and aperture walls, until they enter the lenses, which output the majority of rays that enter in a collimated beam.

Abstract: The present invention features an apparatus and method for collimating light for use with a tiled, flat-panel display having a seamless appearance (i.e., having visually imperceptible seams). A novel, multi-cell, collimation lattice is placed behind the bottom mask of the tiled, flat-panel display assembly, but in front of an illumination source. The lattice is formed from a thin, non-reflective material, so that the acceptable light passing through the lattice is not "blocked", but the unwanted (off-axis) light impinges upon the lattice cell walls and is absorbed.