Patent ID: 7819542
Filing Date: 2010-10-26
Classification: F21Y,G02B,G02F,G09F

Abstract:
1. A planer illumination light source device comprising: a highly directional point-light source; a casing having a bottom plane and a side plane of prescribed sizes, and formed with an opening, the casing having, at an inner wall surface thereof, an inside reflection part and a side reflection part; and radiation side reflection means that covers the opening, wherein the casing is provided with the point-light source arranged at the center of the bottom plane thereof, the radiation side reflection means has first radiation side reflection means that transmits, reflects, or irregularly reflects a part of light from the point-light source, and second radiation side reflection means that is arranged facing a radiation side of the first radiation side reflection means at a certain length therefrom and reflects or transmits a part of light emitted through the first radiation side reflection means, the first radiation side reflection means has a first reflection plane that reflects a part of light from the point-light source into the casing, and a second reflection plane that is arranged facing the first reflection plane and reflects light, the second radiation side reflection means has a third reflection plane that reflects light emitted through the first radiation side reflection means so that the light is reflected in a manner of multipath reflection between the second reflection plane and the third reflection plane, and the first reflection plane of the first radiation side reflection means has a central reflection part in a prescribed area at a spot immediately above the point-light source and an outward reflection part arranged at an outer periphery of the central reflection part, the outward reflection part being formed of a reflection member having a prescribed reflectance that transmits, reflects, or irregularly reflects a part of light, and the central reflection part being formed of a light transmissive reflection part having a higher reflectance than that of the outward reflection part.