Elliptical diffusers used in displays

摘要

A backlit light display comprises a light guide panel, a prismatic film, an asymmetric top diffuser and an LCD. A linear light source is disposed along a side face of the light guide panel. Light from the linear light source is transmitted though the light guide panel where it is spread and uniformly output through a front face to the prismatic film. Light incident on the prismatic film is redirected more along a first direction than along a second direction. This light is directed more normal to the LCD. An asymmetric diffuser is applied between the prismatic film and the LCD panel to smear the periodic information from the prismatic film and eliminate the Moiré fringe pattern resulting from interference between the periodic structure of the prismatic film and the periodic arrangement of pixels in the LCD. The asymmetric diffuser is aligned with respect to the prismatic film such that it scatters and spreads light more in a second direction than the first direction.