| 摘要 |
A discharge lamp lighting device is provided with a control unit for controlling the frequency of an AC current supplied by a power supply unit to a discharge lamp, the frequency being controlled by different schemes in alternately repeated first and second periods. In the first period, the control unit controls the frequency of the AC current so as to be equal to at least one of a plurality of set frequencies, and in the second period, the control unit controls the frequency of the AC current, on the basis of the current and a predetermined frequency during the immediately preceding first period, so as to be equal to a frequency lower than the predetermined frequency. |
