Patent ID: 7165874

Claim:
A backlight unit, comprising: a light source; a light guide plate for introducing light emitted from the light source from an incidence surface provided on an end and emitting the light from an emission surface of the light guide plate; a diffusive reflector disposed to face a second surface of the light guide plate opposite to the emission surface of the light guide plate; and an air space disposed between the light guide plate and the diffusive reflector, wherein the diffusive reflector is provided such that a minute concave-convex portion having a light reflection property is formed on a surface of a base thereof and that the surface having the minute concave-convex portion faces the second surface opposite to the emission surface of the light guide plate, wherein the depths of the concave portions are randomly formed in the range of 0.1 μm to 3 μm and the pitches between the adjacent concave portions are randomly set in the range of 5 μm and 100 μm, and wherein tilt angles inside the concave portions are set in the range of −18° to +18°.