| 摘要 |
<P>PROBLEM TO BE SOLVED: To maintain a lamp voltage in an appropriate range in lighting a high pressure discharge lamp. <P>SOLUTION: A high-pressure discharge lamp-lighting device for AC lightening a high-pressure lamp having a pair of electrodes includes a control means for controlling the lightening frequency of AC lightening, and a detection means for detecting the lamp voltage of the high-pressure discharge lamp. The control means is configured such that the high-pressure discharge lamp is turned on with a main lightening frequency set at a first frequency f1, and when the lamp voltage exceeds a predetermined value, the main lightening frequency is maintained at the n-th frequency fn (2≤n, f(n-1)<fn) for a predetermined period of time, thereafter a combined current waveform having a plurality of frequency components selected from f1 to fn is output, and the ratio of the contained frequency components per unit time is changed so that the average frequency of the combined current waveform is decreased with time, and then the main lightening frequency is changed back to the first frequency f1. <P>COPYRIGHT: (C)2010,JPO&INPIT |
