Patent ID: 6998792

Claim:
An electrodeless discharge lamp operating device comprising: an electrodeless discharge lamp; and a ballast circuit for applying a high-frequency voltage to the electrodeless discharge lamp, wherein the ballast circuit comprises: an AC-DC converter for converting a phase-controlled AC voltage into a DC voltage; a DC-AC converter for converting the DC voltage into a high-frequency voltage, the DC-AC converter being formed so as to intermittently drive the electrodeless discharge lamp due to the existence of an operating period during which the high-frequency voltage is applied to the electrodeless discharge lamp so that the electrodeless discharge lamp is operated, and an extinguishing period during which the generation of the high-frequency voltage is stopped so that the electrodeless discharge lamp is extinguished; and a dimming controller for detecting the turn-on of the phase-controlled AC voltage, for outputting an intermittent command signal that changes the ratio between the operating period and the extinguishing period to the DC-AC converter, and for outputting a signal that maintains an intermittent dimmable operating state even if dimming is in full illumination state.