| 摘要 |
PURPOSE:To reduce the wear of a filament electrode and ensure an increase in output and the lamp life by controlling the supply of high frequency to the both ends of an electric-discharge lamp in the starting of the electric-discharge lamp. CONSTITUTION:A high frequency of the same frequency is supplied to the both ends of an electric-discharge lamp 4 each filament 4A, 4B. During the half cycle of the lamp current, the electrode of the applied voltage to the filament 4A, 4B is inverted at the time when the integral value of the lamp current reaches nearly the half, and the supply of high frequency to the both ends of the electric-discharge lamp 4 from the invertor 3 is limited or stopped until a determined time passes in the starting of the electric-discharge lamp 4. At result, two luminescent points are formed stably in the filaments 4A, 4B, the dispersion of the luminescent point temperature is reduced, and the wear of the filament electrode during lighting is reduced. |
