High pressure discharge lamp with long life

摘要

A short-arc high pressure discharge lamp with a shorter distance between electrodes than a conventional lamp that realizes a long life of at least 3000 hours and suppresses the arc jump phenomenon is disclosed. In the high pressure discharge lamp, an electrode tip 124 is transformed into a semi-sphere by fusing and processing an electrode rod 122 and a coil 123 wound around an end of the electrode rod 122. A thickness "de" and a diameter " phi e" of the semi-sphere are each set in a range predetermined in correspondence with a power input (W) of the short-arc high pressure discharge lamp.