| 摘要 |
PROBLEM TO BE SOLVED: To provide a compact and high-efficiency discharge lamp lighting device by suppressing loss of a switching circuit supplying power to a high-pressure discharge lamp without causing flicker of light due to shimmering of arc inside an arc tube. SOLUTION: The high-pressure discharge lamp lighting device, equipped with a switching circuit such as a step-down chopper circuit 1 for controlling power supplied to the high-pressure discharge lamp DL, and a control circuit varying switching frequencies of the switching circuit in accordance with lamp voltages, further includes a switching frequency setting part (a microcomputer 2) for setting switching frequencies so as to hit given lamp powers, based on the lamp voltages, so that the switching frequency setting part, in case switching frequencies set in accordance with the lamp voltages overlap with acoustic resonance frequency range of the high-pressure discharge lamp DL, sets the switching frequency at some constant frequency other than the acoustic resonance frequency range. COPYRIGHT: (C)2007,JPO&INPIT |
