Patent ID: 8542181

Claim:
A flat panel display device, comprising: a display panel; a lamp for providing a backlight source for the display panel; a power transformation module for providing a power source for the lamp; a non-volatile storage unit for storing program code; and a display controller fabricated on a single silicon, comprising: an image processing module for processing a video source and outputting a processed results to the display panel; and a digital pulse width modulation module for generating a pulse width modulation control signal to control the power transformation module according to an image synchronization signal received from the image processing module, the pulse width modulation control signal having a higher frequency than a frequency of the image synchronization signal, wherein the pulse width modulation control signal is adjustable for a plurality of display modes so as to associate a frequency of the pulse width modulation control signal with the image synchronization signal and synchronize the pulse width modulation control signal with the image synchronization signal in a current display mode selected from said plurality of display modes, wherein the digital pulse width modulation module comprises a pulse width modulator comprising: a phase lock loop unit generating a phase lock signal; a divider for dividing a frequency of the phase lock signal by a divisor; and a comparator generating a comparison result according to a comparison between a threshold value and a signal derived from the divider.