Patent ID: 7703972

Claim:
A back light unit comprising: a first and a second laser light source to generate laser beams; a light guide panel located between the first and the second laser light sources and configured to uniformly transmit the laser beams to a liquid crystal panel; and a first and a second holographic diffuser configured to uniformly diffuse the laser beams onto the light guide panel, wherein the first holographic diffuser is attached to a laser beam emission surface of the first laser light source and is a space away from a first laser beam incidence surface of the light guide panel, wherein the second holographic diffuser is attached to a laser beam emission surface of the second laser light source and is a space away from a second laser beam incidence surface of the light guide panel, and wherein the first and the second holographic diffusers are photographic plates having a respective hologram image, each respective hologram image being recorded on a photosensitive film of the respective photographic plate.