| 摘要 |
PURPOSE:To prevent a bulb of discharge lamp from overheating and hanging by placing spacers comprising low heat conductive material between a heat insulating filter and a bulb of discharge lamp. CONSTITUTION:A discharge lamp 1 is horizontally lit, and a cooling medium such as water is passed from an inlet 8 to an outlet 9 between outer tube 7 and inner tube 6 of a heat insulating filter 4. When the discharge lamp is lit for several tens hours, if the lamp is high power, the bulb 2 tends to hang, but the bulb 2 is prevented from hanging by placing spacers 5 between the lower side of the bulb 2 and heat insulating filter 4. The spacer 5 is made of quartz glass or porcelain. |
