| 摘要 |
PURPOSE:To restrain the influence of a discharge lamp lighting device on human bodies, infrared remote controllers and the like by controlling the frequency of a high-frequency voltage supplied to a discharge lamp so that the frequency used when the discharge lamp is preheated is different from that used when the lamp is lighted. CONSTITUTION:The frequencies of high-frequency voltages output to switching element driving power sources 7-1, 7-2 according to preheating or lighting of a discharge lamp 3 are controlled by a frequency control circuit 200 to below 40 and 30 KHz respectively in response to signals from a lighting detecting circuit 100 for detecting the lighted and preheated state of a discharge lamp 3, so that high-frequency voltages of different frequencies are supplied to the discharge lamp according to the state of the lamp. Selection of frequency is performed in such a manner as preventing an electric shock that may occur if a human body makes contact with the discharge lamp during starting, and also preventing malfunctioning of an infrared remote controller and the like that may be caused when the discharge lamp is lighted. The influence of the discharge lamp lighting device on radios, the infrared remote controller and the like can thus be restrained and also the safety of the lighting device can be enhanced. |
