| 摘要 |
PROBLEM TO BE SOLVED: To structure a driving circuit of a backlight device for a liquid crystal panel with the use of low-cost general-purpose control ICs in place of high-cost exclusive inverter control ICs. SOLUTION: The driving circuit 3 is provided with a driving-pulse generating part 32 (switching elements 32a, 32b) connected to a drive-use direct-current power source Vin of a power source part 4 for generating driving pulses, of which voltages periodically change, due to repetition of ON/OFF switching, an inverter transformer 33, of which a primary winding is connected to the driving-pulse generating part 32 and a secondary winding is connected to a cold-cathode fluorescent lamp 2, a current detecting part 35 (a resistor R1) detecting changes of drive currents flowing between the drive-use direct-current power source Vin and the driving-pulse generating part 32, and a control part 34 (a control IC 34a) carrying feed-back control so that an input power is to be constant based on changes of the drive currents detected by the current detecting part 35. COPYRIGHT: (C)2010,JPO&INPIT |
