GAS DISCHARGE LAMP

文件类型：PDF文档
文件大小：55K
PROBLEM TO BE SOLVED : To improve stability of a light output, in an extra-high pressure discharge lamp of a type made to light after transferring from glow discharge to arc discharge.SOLUTION : A cathode is constituted by coupling a cathode main body made of porous high-melting point metal material made to contain an easily electron emitting matter with a base body made of a high-melting point metal material so as its tip to protrude further than the base body. A tip part of the cathode is formed into a cusp shape with a solid angle of 50° or more, and a glow discharge coil is fitted to a body of the cathode from outside. Pressure of rare gas for glow discharge start-up in discharge gas is preferred to be 101×103 Pa(760 torr) or less and a solid angle of the tip of the cathode is preferred to be 50° or more.