| 摘要 |
PROBLEM TO BE SOLVED: To suppress excessive filament voltage during lighting by increasing a voltage to be applied prior to initiation in a system for lighting in series multiple kinds of discharge lamps having different rated powers, and to flow a sufficient filament preheat current to the discharge lamp prior to initiation. SOLUTION: A lamp load connected in series to a first discharge lamp 11 and a second discharge lamp with an approximately equal rated current is connected to FET4 in an inverter circuit 2 via a series-connected cut-off capacitor 6 and resonance inductor 7. The rated power of the first discharge lamp connected to the resonance inductor 7 is greater than that of the second discharge lamp. For this reason, a voltage to be applied to the lamp load is increased at initiation to increase a preheat current in a way that the first discharge lamp does not light soon even when a large voltage applies to the first discharge lamp, and lights after sufficient preheating takes place. COPYRIGHT: (C)2007,JPO&INPIT |
