| 摘要 |
PROBLEM TO BE SOLVED: To prevent tracking generated between power supply connecting terminals of a base. SOLUTION: This is provided with a discharge lamp 14 wherein both ends of a discharge tube formed by folding a tube in which filament electrodes 14a, 14b are installed at both ends are fixed to one base, and wherein the power supply connecting terminals 15a to 15d connected to the respective filament electrodes are extended outward from the base, with an inverter lighting circuit 9 to light in high-frequency on this discharge lamp by applying a high frequency voltage between the power supply connecting terminals of this discharge lamp, and with an impedance detecting means 26 to detect the impedance between the power supply connecting terminals of the discharge lamp in throwing in the power supply, to stop starting operation of the inverter lighting circuit if the impedance is lower than a prescribed value, to start operation of the inverter lighting circuit if the impedance is higher than the prescribed value, and to stop an impedance detecting function between the power supply connecting terminals of the discharge lamp after starting operation of the inverter lighting circuit. COPYRIGHT: (C)2007,JPO&INPIT |
