| 摘要 |
PROBLEM TO BE SOLVED: To provide a lighting device for a high pressure discharge lamp, which prevents fading-out and/or fluctuation of a discharge arc caused by an acoustic resonance phenomenon within a light-emitting tube and stably lights the high pressure discharge lamp. SOLUTION: In the lighting device for a high pressure discharge lamp equipped with the high pressure discharge lamp, a lamp voltage detecting means, a high-frequency power-supplying means and a control circuit, an extracting means for extracting an upper-limit frequency and a lower-limit frequency in a non-resonant frequency band is provided, and the control circuit contains a frequency shifting means for changing the frequency of high-frequency power within a range between the upper-limit frequency and the lower-limit frequency extracted by the extracting means to shift it to a prescribed frequency determined on the basis of the upper-limit frequency and the lower-limit frequency after this. COPYRIGHT: (C)2003,JPO |
