| 摘要 |
PURPOSE:To provide a discharge lamp lighting device having the capability of stopping the operation of a booster chopper circuit via the interruption of the operation of an inverter circuit without sustaining a power loss. CONSTITUTION:The voltage of a commercial AC power supply E is full-wave rectified via a full-wave rectifier 21, and a booster chopper circuit 22 does not operate, because a field effect transistor Q11 is not operating. An inverter circuit 23 is driven with an inverter control circuit 25. When the inverter circuit 23 is actuated, power is supplied through a startup resistor R11, thereby actuating the circuit 22. When this circuit 22 begins to operate, power is supplied to a chopper control circuit 24. A power factor is increased through the circuit 22. At the same time, the occurrence of a higher harmonic wave is restrained to raise voltage, and this voltage is converted to a high frequency through the circuit 23, thereby turning on a discharge lamp FL at a high frequency. When the inverter circuit 23 is always actuated first, voltage does not rise over the required level, due to a light load acting on the booster chopper circuit 22, and higher reliability is thus ensured. |
