| 摘要 |
PROBLEM TO BE SOLVED: To stably light a discharge lamp at the time of dimming and improve the lamp life in a discharge lamp lighting device lighting the discharge lamp by utilizing a resonance circuit with the high-frequency output of an inverter circuit. SOLUTION: This discharge lamp lighting device is provided with a DC power supply section 1 rectifying AC power AC into a DC voltage, an inverter section 2 having at least one switching element to invert the said DC voltage into a high-frequency voltage, a resonance circuit 3 having at least an inductor L1, a capacitor C2 and a discharge lamp 4 and receiving the said high-frequency voltage to light the discharge lamp 4 by resonance, and an oscillation controller 6 dimmer-controlling the light output of the discharge lamp 4 by changing the operating frequency of the inverter section 2. A step-down means converting the high-frequency voltage of the inverter section 2 into a low voltage is provided, and the operating frequency of the inverter section 2 at the time of dimming is set nearer to the natural oscillation frequency of the resonance circuit 3 at the time of no load. |
