Patent ID: 7208882

Claim:
A lighting device for a high-pressure discharge lamp, comprising: a DC/DC converter circuit including a switching element and a drive circuit configured to drive the switching element, wherein a duty cycle of the switching element controls a DC voltage produced by the DC/DC converter circuit; a DC/AC inverter circuit coupled the DC/DC converter circuit, the DC/AC inverter circuit including a plurality of switching elements; and a logic circuit connected to the drive circuit of the DC/DC converter circuit, wherein prior to a current of the high-pressure discharge lamp reversing polarity, the logic circuit causes the drive circuit to adjust the duty cycle of the switching element so that when the polarity of the current of the high-pressure discharge lamp lit is reversed, an output voltage of the DC/DC converter circuit is 1.5 times or more larger than a voltage of the DC/DC converter circuit at a stable lighting time of the high-pressure discharge lamp.