| 摘要 |
PROBLEM TO BE SOLVED: To detect a lamp voltage with the influence of a transient voltage removed therefrom even if a choke coil is not used. SOLUTION: This discharge lamp device is provided with a sample hold circuit 12 having mask means 129 and 131 for masking a transient voltage part, within a lamp voltage VL, generated by a second capacitor 35 and a secondary winding 47b of a first transformer 47. Thereby, the lamp voltage VL can be prevented from being sampled when the transient voltage is generated, and the lamp voltage VL in normal time can be detected when the transient voltage is not generated. Whereas, in the past, the lamp voltage VL is flattened by using a choke coil and the lamp voltage VL in normal time can be thereby detected, the lamp voltage VL in normal time can be detected by providing the sample hold circuit 12 like that even if the choke coil is not used. COPYRIGHT: (C)2008,JPO&INPIT |
