Patent ID: 8054307

Claim:
A device for driving a light source in an image display device, comprising: input terminals to receive a horizontal synchronization signal and a control signal externally provided; an oscillator to generate a reference signal having a frequency; a controller to modulate the reference signal in response to the control signal and output a modulated signal; a voltage supplying unit to apply AC voltage synchronized with the modulated signal to the light source so as to drive the light source; and a phase difference detecting unit to receive the horizontal synchronization signal and the modulated signal and detect a phase difference between the horizontal synchronization signal and the modulated signal to generate an output signal indicating the phase difference, wherein the oscillator adjusts the frequency of the reference signal in response to the output signal of the phase difference detecting unit so that the horizontal synchronization signal and the reference signal are synchronized with each other, wherein a drive signal of the light source amplitudes in positive and negative polarities, respectively, which have a substantially same value.