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Backlight apparatus for liquid crystal display

  • US 20050140312A1
  • Filed: 12/23/2004
  • Published: 06/30/2005
  • Est. Priority Date: 12/25/2003
  • Status: Active Grant
First Claim
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1. A backlight apparatus for a liquid crystal display having a liquid crystal panel, the backlight apparatus comprising:

  • a diffusing plate that is to be provided on entirety of the liquid display panel;

    a first and a second U-shaped cold-cathode tubes provided on a back surface of the diffusing plate and series-connected to each other; and

    a driver circuit for driving the first and the second U-shaped cold-cathode tubes, the driver circuit including a self-excited inverter for generating high-frequency voltages differing in polarity from each other at both terminals of a secondary winding of a step-up transformer whose midpoint is grounded, wherein the first and the second U-shaped cold-cathode tubes are connected between both terminals of the secondary winding without being interposed by ballast capacitors, and wherein a connecting point between the first and the second U-shaped cold-cathode tubes is ungrounded.

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