Patent ID: 7527411

Claim:
A lightguide plate for a double-sided emitting backlight unit, comprising: a first light-emitting surface for illuminating a first liquid crystal display panel disposed to face the first light-emitting surface; a second light-emitting surface opposite to the first light-emitting surface to illuminate a second liquid crystal display panel that is smaller than the first liquid crystal display panel and disposed to face the second light-emitting surface; and a peripheral surface extending between a periphery of the first light-emitting surface and a periphery of the second light-emitting surface and having a light-receiving surface that receives light from a light source; wherein the second light-emitting surface is provided with a multiplicity of grooves extending parallel to the light-receiving surface and each having a triangular section, wherein the grooves in a part of the second light-emitting surface corresponding to the second liquid crystal display panel are different in configuration from the grooves in a rest of the second light-emitting surface so that a quantity of light per unit area emitted from a part of the first light-emitting surface corresponding to the second liquid crystal display panel is larger than that from a rest of the first light-emitting surface.