Patent ID: 7449842

Claim:
A discharge tube drive circuit comprising: a first and a second drive circuit blocks each having a plurality of drive transformers, the drive transformers each having secondary coils connected to at least a discharge tube; a plurality of switches which forms an inverter for generating high frequency signals; and a control unit for controlling said plurality of switches, wherein said first drive circuit block includes at least a first balance transformer provided at a primary coil side of the plurality of drive transformers in said first drive circuit block; wherein a plurality of primary coils of the plurality of drive transformers in the first drive circuit block and a secondary coil of the first balance transformer are connected in series; wherein said second drive circuit block includes at least a second balance transformer provided at a primary coil side of the plurality of drive transformers in said second drive circuit block; wherein a plurality of primary coils of the plurality of drive transformers in said second drive circuit block and a secondary coil of the second balance transformer are connected in series; and wherein primary coils of the first and second balance transformers are connected in series.