Patent ID: 7011442

Claim:
A planar light source comprising: a light guide plate made of a plate-like, light-transmitting material formed with a light emitting surface on a top side thereof and a reflection surface on a bottom side thereof; and an illuminating light source arranged opposite a light receiving side surface of the light guide plate; wherein light coming from the illuminating light source into the light receiving side surface of the light guide plate is light-path-transformed by actions of the reflection surface and the light emitting surface of the light guide plate to emit a planar light flux from the light emitting surface; wherein chamfered portions are provided at an upper end of the light receiving side surface where the light receiving side surface and the light emitting surface of the light guide plate intersect and at a lower end of the light receiving side surface where the light receiving side surface and the reflection surface of the light guide plate intersect, and wherein the reflection surface of the light guide plate includes a textured reflection surface and asymmetric prisms, which are formed on the reflection surface.