DISCHARGE LAMP LIGHTING DEVICE

摘要

PURPOSE:To provide a discharge lamp lighting device in which a discharge lamp can be smoothly started without failure, and stably lighted. CONSTITUTION:This discharge lamp lighting device has a step-up DC power source circuit 3, an inverter circuit 4 connected between the output terminals of the step-up DC power source circuit 3 to supply AC power to a high pressure discharge lamp 5, and a lighting control circuit 28 for detecting the output voltage and output current of the step-up DC power source circuit 3 to control the lighting of the high pressure discharge lamp. The lighting control circuit 28 detects the extinguishing time of the high pressure discharge lamp 5 at starting together with an extinguishing time detecting circuit 29 and a timer circuit 32 attached thereto, and changes the operating frequency of the inverter circuit 4 over one cycle or more on the basis of this.