Patent ID: 7397198

Claim:
A fluorescent lamp driver, comprising: switching means having two switching elements connected in series, said switching means switches a DC power supply voltage, a first transformer and a second transformer configured to obtain AC voltages each having reverse polarity, as AC voltages excited from primary winding to secondary winding of the respective transformers, on the basis of output voltages of said switching means, switching driving means that drives said switching means in accordance with a required driving frequency, and detecting means that detect a current level flowing through the secondary wiring of said first transformer or said second transformer, wherein a first end of the primary winding of said first transformer and second end of the primary winding of said second transformer are connected to a connection point between said two switching elements and a second end of the primary winding of said first transformer and a first end of the primary winding of said second transformer are connected to an end of one of said two switching elements, wherein: said first transformer and said second transformer are arranged to be located in the vicinity of both ends of said fluorescent lamp, and the AC voltage obtained in the secondary winding of said first transformer is applied to one terminal of said fluorescent lamp and the AC voltage obtained in the secondary winding of said second transformer is applied to the other terminal of said fluorescent lamp, said switching driving means is configured to control said driving frequency in accordance with the current level detected by said detecting means so as to stabilize the current level flowing through said secondary wiring.