Patent attributes
A light source device comprising at least a primary light source (1), a light guide (3) guiding light beamed from the primary light source and having a light incident surface (31) and a light outgoing surface (33), an optical deflector (4) disposed adjacent to the light guide's light outgoing surface and having a light incident surface (41) and a light outgoing surface (42), and a light diffuser (6) disposed adjacent to the optical deflector's light outgoing surface and having a light incident surface (61) and a light out going surface (62), wherein the optical deflector's light incident surface is formed with a plurality of rows of prisms arranged in parallel to each other, and the light diffuser has the full width half maximum of an outgoing light intensity of 1–13 degrees when parallel rays of light are incident, whereby providing a light source device excellent in light utilization efficiency of a primary light source, and also excellent in viewing angle characteristics and quality as an image forming illumination without sacrificing high brightness characteristics.
