| 摘要 |
PROBLEM TO BE SOLVED: To simplify a control circuit of a discharge lamp, and perform optimal control of lamp electric power by arranging a circuit to detect voltage and an electric current of an inverter circuit containing the discharge lamp between both these circuits in a discharge lamp lighting device having a booster chopper circuit and the inverter circuit. SOLUTION: A discharge lamp lighting device having a rectifying circuit 103 to rectify a commercial power source 101, a booster chopper circuit 109 to obtain an input electric current waveform by boosting and smoothing plusating voltage rectified by the rectifying circuit 103 and an inverter circuit 117 to light a discharge lamp 124 by converting DC output of the booster chopper circuit 109 into high frequency voltage, is provided with the following means. A detecting circuit to detect voltage and an electric current of the inverter circuit containing the discharge lamp, is arranged between the booster chopper circuit and the inverter circuit. Lamp electric power is controlled without changing an operating frequency of the inverter circuit by changing output of the booster chopper circuit on the basis of an output signal from this detecting circuit. |
