Patent ID: 7140739

Claim:
A light source device, comprising: a lamp body having a light source lamp and a reflector that holds the light source lamp, and having a reflection surface that reflects the light beam irradiated by the light source lamp; a lamp housing on which the lamp body is attached, the lamp housing having a first section disposed on the light-irradiation side of the lamp body and a second section extending from the first section and opposing at least a part of the side of the lamp body; and a plurality of projections protruding along an optical axis of the light beam irradiated by the light source lamp formed on the lamp housing, the reflection surface of the reflector having a cross section of an approximately concave section and positioning surfaces that are abutted to the plurality of projections of the lamp housing to align the reflector with the lamp housing in the optical axis direction, the positioning surfaces being provided on a distal side of the concave section on an outer periphery of an opening of the reflector, the positioning surfaces being flat and not protruding from the other distal side and shaped in a rectangular form, the plurality of projections being located to correspond to corners of the positioning surfaces, planar shape of the plurality of projections being approximately identical to planar shape of the corners of the positioning surfaces.