ELECTRODELESS DISCHARGE LAMP LIGHTING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide an electrodeless discharge lamp lighting device which lights an electrodeless discharge lamp under proper conditions by following changes in the impedance of the lamp. SOLUTION: A high frequency power generator circuit 2 supplies high frequency power to an electrodeless discharge lamp 1 via a matching circuit 3. From startup to turning-on, the high frequency power is supplied from an oscillator circuit 4a through an amplifier circuit 6, during which the frequency is changed so that the phase difference between output voltage and output current decreases. By lighting the electrodeless discharge lamp 1, high frequency power of a constant frequency is supplied from an oscillator circuit 4b through the amplifier circuit, during which the output voltage of a dc power supply E is controlled so that the output power of the high frequency power generator circuit 2 is held constant.