Patent ID: 7800566

Claim:
A drive device for driving a color light emitting diode (LED) backlight which includes a plurality of color LED arrays, comprising: an I/O interface for inputting/outputting a signal; a control unit configured to control a driving voltage and driving current according to a brightness control signal output from the I/O interface; a DC/DC converter configured to convert an operation voltage into the driving voltage according to the driving voltage control of the control unit; a voltage regulator configured to regulate the driving voltage output from the DC/DC converter to a reference voltage without ripple; a multi-channel driving unit configured to convert the reference voltage output from the voltage regulator into forward voltages of the plurality of color LED arrays according to a plurality of control signals that includes first, second and third control signals; and a current source configured to adjust the amount of the driving current flowing in the color LED backlight according to the driving current control of the control unit; wherein the plurality of color LED arrays includes first, second and third color LED arrays, and the multi-channel driving unit further comprises: a first channel driving portion configured to convert the reference voltage output from the voltage regulator into a first forward voltage of the first color LED array according to the first control signal, the first channel driving portion is implemented by a red channel driving portion; a second channel driving portion configured to convert the reference voltage output from the voltage regulator into a second forward voltage of the second color LED array according to the second control signal, the second channel driving portion is implemented by a green channel driving portion; and a third channel driving portion configured to convert the reference voltage output from the voltage regulator into a third forward voltage of the third color LED array according to the third control signal, the third channel driving portion is implemented by a blue channel driving portion; wherein each of the first, second and third channel driving portions includes: a filter configured to filter a corresponding one of the first, second and third control signals within a predetermined band; an amplifier configured to amplify the control signal output from the filter with a predetermined gain; and a driver configured to convert the reference voltage output from the voltage regulator into the forward voltage according to the control signal output from the amplifier.