Patent ID: 7988312

Claim:
A light source apparatus comprising: a light source for emitting ultraviolet light: a reflecting mirror for reflecting the ultraviolet light emitted from the light source, by a reflecting surface thereof, and for outputting the reflected ultraviolet light through an exit aperture; a gas-blasting structure having a pass aperture through which the ultraviolet light outputted from the reflecting mirror passes, and configured to blast gas onto the reflecting surface, and comprising a housing adapted to house the light source, the reflecting mirror, and the gas-blasting structure, and to circulate air introduced from the outside, wherein the gas-blasting structure comprises: a supply port for receiving supply of the gas from the outside; a plurality of spray ports arranged so as to surround the pass aperture, and configured to spray the gas in order to blast the gas onto the reflecting surface; and a distribution path for distributing the gas introduced through the supply port, to the spray ports, wherein the distribution path is formed in such a ring shape as to surround the pass aperture, wherein the spray ports are arranged so as to be off a line along a direction of introduction of the gas introduced through the supply port, wherein the gas blasted onto the reflecting surface by the gas-blasting structure is an inert gas, the apparatus being configured so that only an inert gas is blasted onto the reflecting surface by the gas-blasting structure, said inert gas being different in composition from said air introduced from the outside, said air containing oxygen and being provided into the housing to cool the apparatus, and said inert gas being provided to prevent said air from being supplied to said reflecting surface of said reflecting mirror to prevent said reflecting surface from becoming cloudy from oxygen radicalized by said ultraviolet light, and wherein air passages are provided in the housing between an exit port for outputting the ultraviolet light to the outside and the gas-blasting structure.