Patent ID: 8092068

Claim:
An optical assembly comprising: at least one light input edge; at least one light source positioned adjacent to the at least one light input edge; a generally planar light output surface located on a first major plane and having a first pattern of well defined optical elements that are projections or depressions on or in the light output surface, each optical element of the first pattern being quite small in relation to a length and width of the optical assembly, each optical element of the first pattern having at least a first sloped surface, with an apex angle being formed by said at least first sloped surface; wherein the apex angle varies at various locations of the optical assembly such that the apex angle is larger in an area closer to the light input edge and smaller in another area further away from the light input edge; a generally planar second surface located on a second major plane and having a second pattern of well defined optical elements that are projections or depressions on or in the second surface, each optical element of the second pattern being quite small in relation to the length and width of the optical assembly, the second major plane being approximately parallel to the first major plane and superimposed thereon; and a reflector layer in close proximity to the second surface.