| 摘要 |
PURPOSE:To prevent electrode substances from being scattered and being deposited on the inner surface of an outer tube by providing an insulating enclosure at least around the electrode of a discharge gap. CONSTITUTION:An insulating enclosure 24 consisting of a glass tube is provided around the electrodes 15 and 16 which form a discharge gap 13 and the electrode substances are prevented from being scattered into the inner surface of an outer tube 1. A ceramic tube which is an insulant other than the glass tube can be used as the insulating enclosure 24. A high pressure discharge lamp 8 is discharge in normal case, and. Once the high pressure discharge lamp 8 has lit out due to the temporary breakdown of power voltage, the discharge gap 13 starts discharging. |
