Patent ID: 7594739

Claim:
A light source device comprising: a discharge lamp; a reflection mirror that reflects a light from said discharge lamp and emits said light, said reflection mirror having an inner reflection surface and an outer back surface opposite to said inner reflection surface; a transparent plate disposed on a light emitting side of said reflection mirror, said transparent plate and said reflection mirror being configured to surround a space, where said reflection mirror has an inlet opening and an outlet opening, both of which being located in the vicinity of an end of said reflection mirror closer to said transparent plate; a case that houses said discharge lamp, said reflection mirror and said transparent plate, said case having an inlet opening formed on a rear side of said case and an outlet opening formed on a front wall of said case, said front wall being disposed on the light emitting side of said reflection mirror and said outlet opening directly opening to the outside of said case; and a conduit provided so as to connect said outlet opening of said reflection mirror and said outlet opening of said case; wherein air flows from said inlet opening of said case, toward said front wall of said case along said outer back surface of said reflection mirror, through said inlet opening of said reflection mirror into said space, out of said space through said outlet opening of said reflection mirror, through said conduit, and through said outlet opening formed on the front wall of said case directly to the outside of said case.