Patent ID: 8432354

Claim:
A backlight control circuit of a display comprising: a logic unit; a drive unit; a decoder; a current setting unit; a current stabilizer; a pulse width modulated generator; a plurality of light sources; and a control unit; wherein the pulse width modulated generator sends pulse width modulated signals to the control unit, the control unit controls the brightness of each light source according to the pulse width modulated signals; the logic unit receives a display module power supply signal from the drive unit and a backlight power supply signal from an external circuit, and sends an enable signal to the control unit; the drive unit sends a first control signal to the decoder, the decoder receives the first control signal and sends a decoded signal to the current setting unit; according to the decoded signal, the current setting unit sends a second control signal and an output voltage to the current stabilizer; the current stabilizer receives the second control signal and generates a steady current; according to the second control signal, the control unit selectively provides the steady current to the corresponding light source, and wherein the logic unit includes a NAND gate and a NOT gate connected in series, the NAND gate receives the display module power supply signal and the backlight power supply signal, the NAND gate sends a intermediate signal to the NOT gate, and the NOT gate generates the enable signal according to the intermediate signal.