文件类型:PDF文档
文件大小:588K
[PROBLEMS] To improve considerably the service life of a lamp by suppressing a chemical reaction between a rare earth metal and an electrode sealed in a discharge vessel. [MEANS FOR SOLVING PROBLEMS] An HID lamp (3) comprises a luminescent part (3a) in the center part and a sealing site (3b) in both end parts. A rod, or one-side sealed pipe (boot) external electrodes (7, 8) formed of Nb are held in a hermetically sealed state in the sealing site (3b) through a sealing material (9) formed of frit glass. Internal electrodes (10, 11) formed of W (tungsten) or Mo (molybdenum) are welded to these external electrodes (7, 8). The surface of the external electrodes (7, 8) formed of Nb rod or the one-side sealed pipe (boot) is formed of a thin film (14) of an oxide of a rare earth metal (e.g. Dy2O3) identical to the rare earth metal halide sealed in the luminescent part (3a).