| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an inexpensive high pressure discharge lamp lighting device, a luminaire and an illumination system capable of surely detecting a half wave discharge condition regardless of polarity of half wave discharge. <P>SOLUTION: The high pressure discharge lamp lighting device has an inverter circuit 2 of a half bridge configuration. A half wave discharge detection circuit 7f of an inverter control circuit 7 outputs a stop signal to a polarity inverting circuit 7g when the lamp voltage VDL is below a prescribed voltage even if time required to reach stable lighting voltage passes after start of a high pressure discharge lamp DL on the basis of a lamp voltage detection signal from a lamp condition detection circuit 4 and a capacitor voltage detection signal from a capacitor voltage detecting circuit 8, and the polarity inverting circuit 7g stops a switching operation of the inverter circuit 2. And, even if the lamp voltage VDL is higher than the prescribed voltage after a certain period of time after start up, if the capacitor voltage Vc3 is more than a normal voltage range, it determines that it is in the half wave discharge condition, and outputs the stop signal to the polarity inverting circuit 7g. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
