Patent ID: 7348959

Claim:
A liquid crystal display device comprising: a signal converter which converts a selectively input analog image signal into a digital image signal according to a sampling clock; a scaler which samples the digital image signal output by the signal converter, to render the digital image signal suitable for a resolution, according to the sampling clock, and generates a horizontal synchronization signal of the input analog image signal; a controller which detects the horizontal synchronization signal and generates the sampling clock according to the detected horizontal synchronization signal; an inverter which is synchronized with the digital image signal and which generates a pulse signal usable to drive a backlight; and a panel driver which receives the sampled image signal from the scaler and displays the received signal, wherein the inverter comprises: a comparer which compares a first power supplied to the panel driver with a second power that is supplied separately from the first power, and which outputs a comparing result signal; an inverter controlling pulse width modulator which generates a pulse width modulation signal synchronized with the horizontal synchronization signal, and is turned on or off according to the comparing result signal; a switching transformer which switches on or off a power source according to the pulse width modulation signal; and the backlight which radiates light when powered by the power source.