| 摘要 |
PROBLEM TO BE SOLVED: To realize reduction of power loss by responding to a wide range of commercial power supply voltage adopted in various parts of the world and avoid function stop of the step-up circuit due to the rise of power supply voltage or action stop of the step-down circuit due to property deterioration of the discharge lamp. SOLUTION: The device comprises a step-up voltage variable circuit 12 that converts the step-up voltage boosted by a step-up circuit 11 into a starting output voltage V<SB>o</SB>for improving the power factor based on the rectified voltage value E<SB>o</SB>of the AC voltage E obtained from the commercial AC power supply, and lights the discharge lamp 6 by inputting the maximum starting output voltage V<SB>o</SB>max to the lighting device 5 when lighting signal S is received, and after the delayed time limit of the delay circuit 17, the output voltage value V<SB>o</SB>of the step-up voltage variable circuit 12 is set so as to variably control in the specified range based on the rectified voltage value E<SB>o</SB>and the discharge lamp 6 is continued lighting by the lighting output voltage V<SB>L</SB>. On the other hand, it is so set that when the lighting output voltage V<SB>L</SB>has reached the upper limit of the specified range for lighting, the maximum starting output voltage value V<SB>o</SB>max is outputted. COPYRIGHT: (C)2004,JPO&NCIPI |
