Patent ID: 7806539
Filing Date: 2010-10-05
Classification: G02B,G02F

Abstract:
1. An optical assembly comprising: a hollow backlight having a first side, a second side superimposed on the first side, and at least one light input edge; at least one LED light source positioned adjacent the at least one light input edge, the at least one light source being quite small in relation both to a length and to a width of the optical assembly, the light from the at least one light source being transmitted in the hollow backlight; a back reflector positioned at or in close proximity to the first side of the hollow backlight for reflecting the light through the hollow backlight and out through the second side; a reflective polarizer having opposite sides, one of the sides being attached to the second side of the hollow backlight, the reflective polarizer having multiple layers, each layer having a refractive index that is different from adjacent layers of the reflective polarizer; and a display or a sheet, film or substrate in close proximity to the other side of the reflective polarizer with an air gap between the reflective polarizer and the display or the sheet, film or substrate; wherein optical deformities that are projections or depressions on or in one or both sides of the reflective polarizer are shaped to redirect the light in a predetermined manner; and wherein at least some of the optical deformities on or in the one side of the reflective polarizer comprise a plurality of light transmissive surfaces and light reflective surfaces, the light reflective surfaces having a reflective coating for redirecting reflected light within the reflective polarizer back toward the other side of the reflective polarizer.