Patent ID: 7391407

Claim:
A back-light driving circuit comprising: a driving voltage generating means for providing a corresponding one of a plurality of driving voltages to each of a plurality of back-lights for causing each of the plurality of back-lights to emit light, wherein each of the back-lights includes at least one light emitting diode having a first terminal and a second terminal, wherein the corresponding one of the driving voltages is provided to the first terminal of the at least one light emitting diode of each of the back-lights, and wherein at least two of the driving voltages have different driving voltage values; and a pulse width modulation (PWM) signal generating means for providing a corresponding one of a plurality of PWM signals to the second terminal of the at least one light emitting diode of each of the plurality of back-lights for controlling chromaticity of the light emitted from each of the plurality of back-lights, the PWM signal generating means comprising a register storing PWM values corresponding to the back-lights, wherein at least two of the PWM signals are associated with different said PWM values.