HIGH-PRESSURE DISCHARGE LAMP OPERATION APPARATUS AND HIGH-PRESSURE DISCHARGE LAMP OPERATION METHOD

摘要

The invention provides a high pressure discharge lamp lighting apparatus which prevents dying out or instabilities of the discharge arc inside the arc tube due to the acoustic resonance phenomena and enables to light the high pressure discharge lamp in a steady state. In the high pressure discharge lamp lighting apparatus having the high pressure discharge lamp, the lamp voltage detecting means, the high frequency power supplying means, and the control circuit, the apparatus includes an extracting means for extracting an upper limit frequency and a lower limit frequency of the resonance-free frequency band, and the control circuit includes a frequency moving means for changing the frequency of the high frequency power within a range defined by the upper limit frequency and the lower limit frequency extracted by the extracting means and then moving the frequency to a predetermined frequency which is determined based on the upper limit frequency and the lower limit frequency.