Patent ID: 7527410
Filing Date: 2009-05-05
Classification: G02F,H04M

Abstract:
1. A backlight unit comprising a light source and an optical sheet which supplies light from the light source to a display of a size of 32 inches or larger, wherein: the optical sheet further comprises: a light scattering layer; a plurality of light reflecting portions in stripes provided on a non-incident surface of the light scattering layer; light transmitting portions each provided between each adjacent pair of the plurality of light reflecting portions; and lenticular sheets formed in stripes along a longitudinal direction of a unit of each of the plurality of light reflecting portions and including a lens portion in which a plurality of unit convex cylindrical lenses are arranged in parallel with each other on the plurality of light reflecting portions and the light transmitting portions by the side of the display, and a non-lens surface on which light transmitting the light transmitting portions is made incident, the plurality of unit convex cylindrical lenses corresponding respectively to the light transmitting portions one by one, perpendicular lines from peaks of the plurality of unit convex cylindrical lenses to the non-lens surfaces thereof including the light transmitting portions, wherein both of longitudinal ends of each of the plurality of light transmitting portions are free, the light scattering layer comprises one of polycarbonate, polystyrene and methacryl styrene (MS) resin and has a thickness of 1 mm to 5 mm, a pressure loss ΔP of air flowing through the light transmitting portions has a relationship of 0 (Pa)<ΔP<7×10