| 摘要 |
<P>PROBLEM TO BE SOLVED: To detect a rectified discharge in a discharge lamp before turning the discharge lamp off. <P>SOLUTION: A voltage conversion circuit 171 converts a voltage which has developed at opposite ends of a coupling capacitor C43 to generate a direct-current voltage. A voltage rise detection circuit 180 detects whether the direct-current voltage generated by the voltage conversion circuit 171 is higher than a prescribed upper limit voltage. A voltage drop detection circuit 190 detects whether the direct-current voltage generated by the voltage conversion circuit 171 is lower than a prescribed lower limit voltage. In at least either of the cases where the voltage rise detection circuit 180 detected that the direct-current voltage generated by the voltage conversion circuit 171 is higher than the prescribed upper limit voltage and where the voltage drop detection circuit 190 detected that the direct-current voltage generated by the voltage conversion circuit 171 is lower than the prescribed lower limit voltage, a microcomputer 160 generates an oscillation stop signal, and a control power supply circuit 150 stops generating an alternating-current voltage. <P>COPYRIGHT: (C)2013,JPO&INPIT |
