POWER SUPPLY DEVICE, BACKLIGHT DEVICE, AND LIQUID CRYSTAL DISPLAY

摘要

PROBLEM TO BE SOLVED: To provide a power supply device capable of driving a rare gas discharge tube of mercury-free type which is efficient, using a piezoelectric transformer having little electromagnetic noise. SOLUTION: A rectifying/smoothing part 101 and a switching means 102 are provided in between a piezoelectric transformer 10 and a rare gas discharge tube 103 as a load. A sinusoidal wave voltage, outputted from the piezoelectric transformer 10, is rectified and is smoothed to a DC voltage at the rectifying/smoothing part 101. Then the switching means 102 on/off controls to supply a rectangular wave voltage with respect to the rare gas discharge tube 103. COPYRIGHT: (C)2004,JPO&NCIPI