Patent ID: 8030850

Claim:
A fluorescent lamp driving apparatus comprising: a first inverter which outputs a first alternating current (AC) voltage to one end of the fluorescent lamp; a second inverter which outputs a second AC voltage having a reversed phase to the first AC voltage to the other end of the fluorescent lamp; a first current-voltage converting circuit which converts a secondary current of a transformer in the first inverter to a voltage and outputs the voltage as a first detection voltage; a second current-voltage converting circuit which converts a secondary current of a transformer in the second inverter to a voltage and outputs the voltage as a second detection voltage; and a first abnormality detection circuit which determines a circuit abnormality when the potential difference between the first and second detection voltages exceeds a predetermined first threshold voltage, wherein the first abnormality detection circuit includes: a first level shift circuit which shifts level of the first detection voltage by the first threshold voltage; a second level shift circuit which shifts level of the second detection voltage by the first threshold voltage; a first comparator which compares the second detection voltage with output voltage of the first level shift circuit; a second comparator which compares the first detection voltage with output voltage of the second level shift circuit; and an OR gate which outputs OR of outputs of the first and second comparators, and the first abnormality detection circuit determines a circuit abnormality on the basis of the output of the OR gate.