Patent ID: 6669350
Filing Date: 2003-12-30
Classification: G02B

Abstract:
A planar light source system comprising:at least one primary light source of substantially point-shaped light source; a light guide having a light incident face on which light emitted from said primary light source is incident, guiding the incident light and having a light emission face from which the incident light is emitted; and a light deflecting device for controlling a direction of light emission from said light guide, wherein said primary light source is disposed at a corner portion or an end surface of said light guide, and many substantially arc-shaped elongated lenses are formed in parallel to each other on at least one surface of said light deflecting device so as to surround said primary light source, wherein said light deflecting device has a light incident surface which confronts said light guide, and said substantially arc-shaped elongated lenses are formed on at least the light incident surface, wherein each of said elongated lenses formed on said light deflecting device comprises an elongated prism having two prism faces, and light incident through at least one prism face is internally reflected and emitted from a light emission surface in a desired direction, and wherein each elongated prism of said light deflecting device comprises two prism faces, one prism face being farther from said primary light source said another prism face being nearer to said primary light source, and an intersecting angle between said prism face farther from said primary light source and a reference plane of said light deflecting device is equal to 40 to 80 degrees.