Abstract: To realize high irradiation efficiency and intensity stability for extending lifetime of the short-arc discharge lamp to be used for IC exposure apparatus or the like. For this end, mercury and rare gases are sealed in the inner space 21 of the discharge tube 1. The rare gases are a mixture of a relatively high molecular weight rare gas such as xenon, krypton, argon, etc. and 5%-40% by volume of a relatively low molecular weight rare gas such as helium, neon, etc. And pressure of the mixed rare gases is set to 2 atmospheric pressure or higher. The anode 3 comprises the columnar body portion 14, the tapered portion 13 and the flat portion 12.

Abstract: To realize high irradiation efficiency and intensity stability for extending lifetime of the short-arc discharge lamp to be used for IC exposure apparatus or the like. For this end, mercury and rare gases are sealed in the inner space 21 of the discharge tube 1. The rare gases are a mixture of a relatively high molecular weight rare gas such as xenon, krypton, argon, etc. and 5%-40% by volume of a relatively low molecular weight rare gas such as helium, neon, etc. And pressure of the mixed rare gases is set to 2 atmospheric pressure or higher. The anode 3 comprises the columnar body portion 14, the tapered portion 13 and the flat portion 12.

Abstract: In a construction of electrode for a high pressure discharge lamp used with maintaining a high input of electricity, which discharge lamp comprises a valve composed of a luminescence tube having a swelled portion at the middle thereof, and an anode and a cathode placed opposite to each other, the cathode is composed of a metal with a high melting temperature doped with a electron-emitting substance and having a tapered portion toward the discharge side, the slope portion of said tapered portion being subjected to carburization at said tapered portion, and a non-treated portion being formed at the edge of the tapered portion continuous to the carburized portion.

Abstract: A high pressure discharge lamp comprises a portion composed of a luminescence tube having a swelled portion at the middle thereof, and an anode and a cathode placed opposite to each other, the cathode is composed of a metal with a high melting temperature doped with a electron-emitting substance and having a tapered portion toward the discharge side, the slope portion of said tapered portion being subjected to carburization at said tapered portion, and a non-treated portion being formed at the edge of the tapered portion continuous to the carburized portion.

Abstract: A curing apparatus utilizing ultraviolet radiation for curing a coating over the surface of a line-shaped medium such as an optical fiber, comprising: a pair of reflecting mirrors, each of which has an elliptical mirror surface, the ratio between the major and minor axes of which is within a range from 1.02 to 1.35; a source for producing ultraviolet radiation having a tube which is disposed along a first focal axis of the pair of reflecting mirrors for emitting ultraviolet radiation and has a diameter within a range from 12 mm to 24 mm and a light emission length equal to or longer than 15 cm; and an ultraviolet radiation transmission hollow tube which is disposed along a second focal axis of the pair of reflecting mirrors and through which the line shaped medium is passed in the axial direction of the hollow tube. The ultraviolet radiation emitting tube is air-cooled.