| 摘要 |
PURPOSE: To provide a discharge lamp lighting device which can instantaneously light a discharge lamp without making it unsightly and making circuit constitution complex. CONSTITUTION: When a dimming signal is on, the high-frequency alternating current of an inverter circuit 23 is applied between the filaments FLa, FLb of the fluorescent lamp FL, and voltages are induced in the first and second secondary windings Tr 2, Tr 3 of a filament preheating transformer Tr to preheat the filaments FLa, FLb of the fluorescent lamp FL so as to light the fluorescent lamp FL. When the dimming signal is off, a chopper control circuit 22 is held in its original state, and the output voltage of the inverter circuit 23 is lowered to a voltage at which the fluorescent lamp FL goes out without discharging, so as to turn off the fluorescent lamp FL. The inverter circuit 23 outputs low voltages, and the filaments FLa, FLb are preheated with the voltages applied thereto; when the dimming signal is on, the lamp is lighted again quickly without soft start since the filaments FLa, FLb are preheated. |
