Patent ID: 8144110

Claim:
A backlight system, comprising: a power input circuit; a detection circuit; a control circuit; a light emitting diode driving circuit; and a light emitting diode array; wherein the detection circuit is configured to detect a connection state of the power input circuit with respect to an external power source, and send a corresponding connection state signal to the control circuit, the detection circuit comprises an input terminal capable of receiving voltages, a voltage sampling circuit configured for sampling voltages of the input terminal and outputting sample voltages, and a transistor having a base capable of receiving the sample voltages, an emitter capable of being connected to a constant voltage, and a collector capable of outputting detection signals, the control circuit is configured to output a control signal to the light emitting diode driving circuit according to the connection state signal, the control circuit comprises a NOT gate and an AND gate, an input terminal of the NOT gate is connected to the collector of the transistor, an output terminal of the NOT gate is connected to a first terminal of the AND gate, a second input terminal of the AND gate is capable of receiving backlight control signals from an external device, and an output terminal of the AND gate is capable of outputting the control signal to the light emitting diode driving circuit, and the light emitting diode driving circuit is configured to drive or shut down the light emitting diode array according to the control signal.