Patent ID: 7205726
Filing Date: 2007-04-17
Classification: H05B

Abstract:
1. A discharge lamp drive apparatus comprising: an inverter circuit; first and second transformers; a current detection circuit; and a signal processor, wherein the inverter circuit is a circuit which converts a direct-current voltage into an alternating voltage and outputs the converted voltage, the first transformer receives the alternating voltage from the inverter circuit at an input winding thereof, and supplies a first alternating voltage to a first discharge lamp connection terminal group from an output winding thereof, the first discharge lamp connection terminal group includes a plurality of discharge lamp connection terminals, the plurality of discharge lamp connection terminals being configured to be connected with a plurality of discharge lamps, the second transformer receives the alternating voltage from the inverter circuit at an input winding thereof, and supplies a second alternating voltage to a second discharge lamp connection terminal group from an output winding thereof, the second discharge lamp connection terminal group includes a plurality of terminals corresponding to the first discharge lamp connection terminal group, the plurality of terminals being configured to be connected with a plurality of discharge lamps, the current detection circuit detects a current flowing through at least one discharge lamp connection terminal included in the first or second discharge lamp connection terminal group and a sum total of currents flowing through the other terminals included in the first or second discharge lamp connection terminal group, and the signal processor receives a current detection signal from the current detection circuit, and generates a signal which is used to detect an open state of a discharge lamp from the current detection signal.