DISCHARGE LAMP LIGHTING DEVICE AND ILLUMINATION FIXTURE

PROBLEM TO BE SOLVED: To supply a constant resonance boosting voltage, avoid that a switching element is actuated in an advanced phase state, and reduce electric stress to parts, in an unloaded state in which a discharge lamp is not lighted. SOLUTION: In a discharge lamp lighting device in which a starter 3 which generates a high voltage for start-up by an LC resonance action with a high frequency voltage generated in an inverter circuit part 2 to output a square wave alternate current electric power to the discharge lamp 4 as a power source is provided, and in which an operating frequency of the high frequency voltage has a frequency sweep in the vicinity of a resonance frequency or its odd-number multiplied frequency of the starter 3, a voltage detecting means 5 to detect the resonance boosting voltage is installed, and when the detected resonance boosting voltage reaches nearly the target voltage value, the resonance boosting voltage is made to stop. Or, when the resonance boosting voltage reaches nearly the target voltage value, the frequency is fixed for a certain period. Or, when the resonance boosting voltage reaches nearly the target voltage value, the direction of the frequency sweep is reversed. COPYRIGHT: (C)2005,JPO&NCIPI