| 摘要 |
PURPOSE:To guarantee lighting of an AC dicharge lamp and to eliminate flicker and degradation of lifetime of the AC discharge lamp by normally feedback controlling consumprion power od the AC discharge lamp to be constant with good response characteristics and reducing response characteristcs of a system for making the feedback control to a level lower tha that of the response characteristics after lighting in the case of lighting of the AC discharge lamp or the like. CONSTITUTION:A high voltage is applied to an AC discharge lamp 20 to light the AC discharge lamp, power consumed by the AC lamp 20 is detected by power detection circuit 24, 28 during lighting and after lighting, and power consumption of the AC discharge lamp 20 is feedback-controlled to be constant by stationary power control circuits 26, 30. In the case of lighting of the AC discharge lamp or the like, response characteristics of a system for making the feedback control is reduced to a level lower than that of the response chracteristics after lighting by a response characteristics switching circuit 43. Accordingly, the AC discharge lamp 20 can be surely lighted without any negative influence to the AC discharge lamp 20. |
