| 摘要 |
PURPOSE:To light a discharge lamp instantaneously, and reduce stress on elements composing an inverter circuit caused by instantaneous lighting. CONSTITUTION:A device is provided with a high frequency power supply DN1 to supply high frequency power for lighting and preheating of a discharge lamp DL1, a control part CR1 to regulate the high frequency power to be supplied to the discharge lamp DL1 by controlling an oscillation frequency of the high frequency power supply DN1 in accordance with a dimming signal, and a fade out part FO1. The fade out part FO1 changes the oscillation frequency of the high frequency power supply DN1 into a lighting-off frequency with which a voltage applied to the discharge lamp DL1 becomes under a lighting maintaining voltage in response to a discharge lamp lighting-off signal temporarily, and it is then changed into a stand-by frequency with which the discharge lamp DL1 is kept in a preheat condition where it can be lighted instantaneously, and with which an applied voltage on the discharge lamp DL is under an ignition voltage. |
