Patent ID: 7926999
Filing Date: 2011-04-19
Classification: G02B

Abstract:
1. A planar light-emitting device comprising: two light sources each having a light-emitting surface to emit light; an elongated first lightguide plate comprising an upper surface, a lower surface opposite to the upper surface, and peripheral side surfaces between the upper and lower surfaces, the peripheral side surfaces including two opposite light entrance end surfaces each facing the light-emitting surface of the corresponding light source, the elongated first lightguide plate further comprising a light exit side surface to emit light transmitted through the first lightguide and a reflecting side surface, the light exit side surface and the reflecting side surface being opposite to each other; wherein: t t t wherein the first lightguide plate is configured to satisfy the following condition: t further wherein the first lightguide plate is tapered with its thickness gradually decreased from the reflecting side surface toward the light exit side surface that is opposite to the reflecting surface, and the first lightguide is further tapered with its thickness gradually decreased from each of the two opposite light entrance end surfaces toward the light exit side surface, further comprising a flat plate-shaped second lightguide plate having a light entrance side edge surface that is disposed to face the light exit side surface of the first lightguide plate.