| 摘要 |
<P>PROBLEM TO BE SOLVED: To suppress an input current input into a discharge lamp lighting device 2 when a voltage value input of an alternating current power supply AC is reduced, and suppress excessive generation of heat of electronic parts to constitute the discharge lamp lighting device 2. <P>SOLUTION: The discharge lamp lighting device 2 has a boost chopper circuit 20 which constitutes a boost chopper to boost a pulsating voltage that a power supply rectifying circuit 10 outputs, and has a voltage setting part 22 that detects the boosted direct current voltage Vo and outputs the detected voltage, an inverter circuit 40 which converts the direct current voltage Vo into a high-frequency current and lights a discharge lamp LA, and a control circuit 50 which, when the detected voltage detected by the voltage setting part 22 falls, controls an oscillation frequency of the inverter circuit 40 based on the detected voltage and reduces a power supplied to the discharge lamp LA. Accordingly, even if a voltage value of the alternating current power supply AC is reduced to a much lower voltage than a rated voltage, the input current is restrained from getting excessive and the excessive generation of heat of the electronic parts constituting the discharge lamp lighting device 2 can be suppressed. <P>COPYRIGHT: (C)2010,JPO&INPIT |
