Patent ID: 8382355
Filing Date: 2013-02-26
Classification: G02B

Abstract:
1. A planar light source device comprising: a point light source; and a light guide plate that spreads out light emitted from the point light source, wherein the light guide plate includes: an emitting surface from which the light is emitted; an opposite emitting surface that is a surface opposite to the emitting surface; and a side surface that connects the emitting surface and the opposite emitting surface; wherein the point light source is arranged adjacent to the side surface of the light guide plate and is arranged at the opposite emitting surface side of the light guide plate, wherein the light guide plate has a cylindrical hole that is formed at a position which corresponds to the position where the point light source is arranged, and wherein the hole forms an opening at the side surface to emit a portion of the light from the point light source to the outside of the light guide plate, the opening being located relative to the point light source such that the portion of the light emitted through the hole to the outside of the light guide plate is light that would reach to the side surface and would not be totally reflected at the side surface.