DISCHARGE LAMP LIGHTING DEVICE

摘要

PROBLEM TO BE SOLVED: To have an optimum control of movement of mercury in a discharge lamp with amalgam. SOLUTION: A discharge lamp with its one lamp end containing mercury vapor pressure controlling material by different volume from the other end and with inflection point within operating temperature range is combined with a lighting means which has a virtually plus/minus asymmetric output waveform. Then, a plus direct current voltage ingredient is applied to the lamp tube end with the more mercury vapor pressure controlling material, and when a certain time elapses after the lamp lighting, the direct current voltage ingredient is decreased or virtually annihilated. The direct current voltage ingredient is increased at light controlling time as compared with the full lighting time. For deciding the lamp tube end with more mercury vapor pressure control material, a temperature sensor or a brightness sensor is set at both ends of the lamp.