HIGH-PRESSURE DISCHARGE LAMP

摘要

PROBLEM TO BE SOLVED: To provide a high-pressure discharge which realizes long life of 3,000 hours or more and yet curtails arc-jump phenomenon, even as a short-arc type discharge lamp having a shorter arc length than a conventional one with distance between electrodes (De) of not more than 1.5 mm. SOLUTION: A tip part 124 of an electrode is formed to get a convex shape by fusing and processing an electrode shaft 122 and a coil 123 wound around the tip part of the electrode shaft 122, and at the same time, the thickness (de) and the diameter (ϕe) of the above convex-shaped part are respectively to be within given ranges in accordance with the lamp input (W).