Abstract: An LCD device includes a memory for storing image signals, a PWM clock generator for generating an aperiodic PWM clock signal according to a clock signal and a gamma correction signal, a PWM counter for generating count values corresponding to the aperiodic PWM clock signal generated by the PWM clock generator, a comparing device for comparing the image signals transmitted from the memory and the count values transmitted from the PWM counter, a PWM signal generator for generating a PWM signal with a corresponding pulse width according to a comparing result of the comparing device, an LCD panel, and a drive circuit for driving the LCD panel according to the PWM signal.