High-pressure discharge lamp, and manufacturing method, lighting method, and lighting device for the same

摘要

A high pressure discharge lamp having a pair of electrodes with a space of 0.5 mm to 2.0 mm inclusive between them and disposed in an arc tube. An electrical discharge takes place between the electrodes. Each of the electrodes has an electrode rod and a head that is provided at the discharge side end of the electrode rod and having a larger diameter than the electrode rod. A surface of the head being opposite to the other electrode is convexly curved and a protruding part is formed in the vicinity of the center portion of the end of the head.