Patent ID: 8212964

Claim:
A backlight unit, comprising: a reflection sheet; a plurality of lamps arranged over the reflection sheet and with a first distance between adjacent lamps; a first diffuser plate disposed over the plurality of lamps and spaced apart from the reflection sheet with a second distance, the first diffuser plate having a first surface facing the reflection sheet and a second surface opposite to the first surface, wherein the first surface is flat and the second surface includes first patterns; and a second diffuser plate disposed over the first diffuser plate, the diffuser plate having a third surface facing the first diffuser plate and a fourth surface opposite to the third surface, wherein the third surface is flat and the second surface includes second patterns, wherein a ratio of the first distance over the second distance is within a range of more than 1.35 and less than and/or equal to 2.75, wherein ones of the first patterns and the second patterns have lenticular lenses, and others of the first patterns and the second patterns have prisms, and wherein each of the prisms has an unevenness at a peak along a first direction parallel to the lamps.