Patent ID: 6870327

Claim:
An electrode-less discharge lamp lighting apparatus which is electrically connected to a dimming unit, comprising: an electrode-less discharge lamp; and a lighting circuit operable to apply a high-frequency voltage to the electrode-less discharge lamp, wherein the lighting circuit includes: an AC/DC converting unit operable to convert a phase-controlled AC voltage outputted from the dimming unit into a DC voltage; a DC/AC converting unit operable to convert the DC voltage into a high-frequency voltage and operable to intermittently drive the electrode-less discharge lamp by applying the high-frequency voltage to the electrode-less discharge lamp during a lighting-up period of the electrode-less discharge lamp so that the electrode-less discharge lamp illuminates and by halting a generation of the high-frequency voltage during a lighting-out period of the electrode-less discharge lamp so that the electrode-less discharge lamp is extinguished; and a dimming controlling unit operable to detect a timing of a turn-on of the phase-controlled AC voltage, wherein, based on the detected timing, the dimming controlling unit outputs an intermittent command signal to vary a ratio between the lighting-up and lighting-out periods and allows a current whose value is at least a threshold to flow across output terminals of the AC/DC converting unit for at least a duration of a time lag between the turn-on of the phase-controlled AC voltage and the generation of the high-frequency voltage by the DC/AC converting unit.