DISCHARGE LAMP LIGHTING DEVICE

PROBLEM TO BE SOLVED: To provide a discharge lamp lighting device capable of protecting an inverter-controlled integrated circuit, without complicating a circuit configuration. SOLUTION: By structuring a MOSFET Q6 constituting a preheating control circuit 3 not to ground its source, a over-voltage will not be impressed on a Vboot terminal, which can therefore be protected. Further, even if a source of the MOSFET Q6 constituting the preheating control circuit 3 is grounded, a constant voltage (Zener) diode DZ171 provided at a boot-strap part 5 prevents the over-voltage from being impressed on the Vboot terminal, which can therefore be protected. COPYRIGHT: (C)2007,JPO&INPIT