Patent ID: 7791284

Claim:
A cold-cathode tube driving apparatus comprising: a booster transformer; a plurality of cold-cathode tubes; switching elements connected to said plurality of cold-cathode tubes; a time division control circuit for lighting one or more of said plurality of cold-cathode tubes in a time division manner by use of a high frequency voltage after boosted by said booster transformer an inverter circuit generating the high frequency voltage at a predetermined cycle, wherein said time division control circuit divides the cycle of the high frequency voltage generated by said inverter circuit or the cycle of current supplied from said inverter circuit to the plurality of said cold-cathode tubes into two or more periods and lights one or more of said plurality of cold-cathode tubes for respective time-divided period sequentially by use of the high frequency voltage outputted from said booster transformer a resistance element which is connected in series to said plurality of cold-cathode tubes respectively and is connected in parallel to said switching elements respectively for applying bias current, a resistance element connected between said switching elements and a ground respectively for detecting current and a resistance element arranged at the ground side of a primary wiring or a secondary wiring of said booster transformer for detecting all secondary-side current.