DISCHARGE LAMP LIGHTING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device capable of reducing a filament current at lighting time while securing a sufficient preceding preheating current. SOLUTION: This discharge lamp lighting device has a boosting chopper part 11 for converting an AC power source into DC voltage, and a discharge lamp 13 for supplying a high frequency AC power source via a resonance circuit composed of an inductor L2 and a capacitor C4. A second resonance circuit composed of a capacitor C9 and a preheating transformer T2 is arranged on the output end of an inverter part 12, and a pair of coils on the secondary side of the preheating transformer T2 are respectively connected to a pair of filaments of the discharge lamp 13. The discharge lamp lighting device is provided with a chopper control part 16 for controlling the boosting chopper part 11 so that output voltage of the boosting chopper part 11 of a lighting period reduces more than output voltage of a preceding preheating period, and an inverter control part 14 for controlling the inverter part 12 so that an oscillating frequency of the inverter part 12 of the preceding preheating period reduces more than a resonance frequency of the second resonance circuit.