| 摘要 |
PROBLEM TO BE SOLVED: To reduce a light output difference even at the low flux of light in a lighting device of an inverter type which lights a plurality of discharge lamps in parallel. SOLUTION: The lighting device of the discharge lamp is provided with an inverter 2 which is connected to a DC power supply 1 and converts a DC voltage into a high frequency voltage, a resonance circuit 3 which is connected to an output of the inverter 2 and has an inductor L and a capacitor C, a load circuit in which a plurality of the discharge lamps 11, 12 are connected in parallel to the output end of the resonance circuit 3, and a control circuit which carries out the light-control lighting of the discharge lamps 11, 12 by changing an oscillation frequency or a ratio of a high-output period and a low-output period of the inverter 2. In order to reduce a current difference between the discharge lamps in the vicinity of rated currents of the discharge lamps 11, 12, the discharge lamps 11, 12 are connected in parallel through a balancer T, and as a correction means to reduce the current difference between discharge lamps in the vicinity of light-control lower limits of the discharge lamps 11, 12, a capacitor Cb for correction is connected in parallel between output ends of the balancer T. COPYRIGHT: (C)2008,JPO&INPIT |
