| 摘要 |
<P>PROBLEM TO BE SOLVED: To solve such problems in a surface light source device wherein light from a point light source is reflected on side surfaces of a light guide plate and is not spread uniformly to cause luminance unevenness, and a light utilization efficiency is low since the light is emitted through the light guide plate to be reflected on a reflecting plate. <P>SOLUTION: The surface light source device 100 includes a flat light guide plate 13 with a rectangular shape in a plan view, and the light guide plate includes a point light source 16 having an outgoing surface facing the opening part, a pair of second side surfaces 13b facing to each other, and a hole 13c disposed on the counter-outgoing surface and opening near one of first side surfaces, and disposed in the hole 13c. At least part of each surface of the pair of the second side surfaces is a prism having ridge lines in the direction perpendicular to the outgoing surface and formed such that a cross section in a direction parallel to the outgoing surface has serrate repeating irregularity. With this configuration, the light from the point light source can be uniformly and effectively spread on the light guide plate to prevent luminance unevenness. <P>COPYRIGHT: (C)2010,JPO&INPIT |
