| 摘要 |
PURPOSE:To obtain an easy start of electric discharge and decrease the time required for a restart, by providing in the outer surface of a luminous tube end part a heating body for heating at least one of the electrodes provided in both ends of a luminous tube. CONSTITUTION:Main electrodes 2, 3 are arranged in both ends of a luminous tube 1 and a filament 5 consisting of tungsten is connected to the main electrode 2. Then the main electrodes 2, 3 are connected to a starter device 12 through lead wires 8, 9 simultaneously the filament 5 is connected to the starter device through a lead wire 10. When a high pressure mercury vapor lamp, after being once turned off, is restarted, an electric current is allowed to flow in the filament 5 from the starter device 12 through the lead wires 10 and 8 to keep the filament 5 in a heated state, then voltage is applied across the main electrodes 2, 3 from the starter device 12 through the lead wires 8 and 9 to start electric discharge. In this way, temperature of the main electrode can be easily raised to perform easy emission of an electron. |
