Display device, discharge circuit and discharge method

1 . A discharge circuit, comprising:

a first subcircuit, coupled between a power supply voltage and a first reference voltage, wherein the first subcircuit is enabled to provide a first discharge path between the power supply voltage and the first reference voltage, and generates a discharge control signal; and

a second subcircuit, coupled between the power supply voltage and a second reference voltage, wherein the second subcircuit is coupled to the first subcircuit for receiving the discharge control signal, and the second subcircuit provides a second discharge path between the power supply voltage and the second reference voltage according to the discharge control signal,

wherein the first subcircuit comprises:

a first transistor, having a first end receiving the power supply voltage and a control end receiving a bias voltage; and

a first resistor, coupled between a second end of the first transistor and a first reference voltage,

wherein a connection end between the second end of the first transistor and a first end of the first resistor generates the discharge control signal.

2 . The discharge circuit according to claim 1 , wherein the first subcircuit activates the first discharge path at a first time point, and the second subcircuit activates the second discharge path at a second time point after the first time point.

3 . The discharge circuit according to claim 2 , wherein the power supply voltage is discharged by the first discharge path and the second discharge path after the second time point to a third time point.

4 . The discharge circuit according to claim 1 , wherein the first subcircuit further comprises:

a switch, coupled between a connection path between the first resistor and the first reference voltage, and controlled by an enable signal.

5 . The discharge circuit according to claim 4 , wherein the switch is turned on according to the enable signal during a power-off operation.

6 . The discharge circuit according to claim 1 , wherein the second subcircuit comprises:

a second transistor, having a first end receiving the power supply voltage, and a control end receiving the discharge control signal; and

a second transistor, coupled between a second end of the second transistor and a second reference voltage.

7 . The discharge circuit according to claim 6 , wherein the second reference voltage is larger than the first reference voltage.

8 . The discharge circuit according to claim 6 , wherein the discharge control signal is reduced from the power supply voltage to a first voltage to turn-on the second transistor, wherein the first voltage equals a summation of a threshold voltage of the second transistor and the second reference voltage.

9 . A display device, comprising:

a voltage generating circuit, receiving a power supply voltage, generating a plurality of operation voltages, and providing the operation voltages to a plurality of display drivers; and

a discharge circuit, receiving the power supply voltage, and is configured to discharge the power supply voltage during a power-off operation, wherein the discharge circuit comprises:

a first subcircuit, coupled between a power supply voltage and a first reference voltage, wherein the first subcircuit is enabled to provide a first discharge path between the power supply voltage and the first reference voltage, and generates a discharge control signal; and

a second subcircuit, coupled between the power supply voltage and a second reference voltage, wherein the second subcircuit is coupled to the first subcircuit for receiving the discharge control signal, and the second subcircuit provides a second discharge path between the power supply voltage and the second reference voltage according to the discharge control signal,

wherein the first subcircuit comprises:

a first transistor, having a first end receiving the power supply voltage and a control end receiving a bias voltage; and

a first resistor, coupled between a second end of the first transistor and a first reference voltage,

wherein a connection end between the second end of the first transistor and a first end of the first resistor generates the discharge control signal.

10 . The display device according to claim 9 , wherein the first subcircuit activates the first discharge path at a first time point, and the second subcircuit activates the second discharge path at a second time point after the first time point.

11 . The display device according to claim 10 , wherein the power supply voltage is discharged by the first discharge path and the second discharge path after the second time point to a third time point.

12 . The display device according to claim 10 , wherein the voltage generating circuit comprises:

a voltage boosting circuit, for generating a gate voltage by boosting the power supply voltage; and

a voltage divider, coupled to the voltage boosting circuit, generating a first data voltage and a second data voltage by dividing the gate voltage,

wherein the voltage boosting circuit provided the gate voltage to a plurality of gate drivers, and the voltage divider provides the first data voltage and a second data voltage to a plurality of source drivers.

13 . The display device according to claim 10 , wherein the first subcircuit comprises:

a switch, coupled between a connection path between the first resistor and the first reference voltage, and controlled by an enable signal.

14 . The display device according to claim 13 , wherein the second subcircuit comprises:

a second transistor, having a first end receiving the power supply voltage, and a control end receiving the discharge control signal; and

a second transistor, coupled between a second end of the second transistor and a second reference voltage.

15 . The display device according to claim 14 , wherein the second reference voltage is larger than the first reference voltage.

16 . The display device according to claim 14 , wherein the discharge control signal is reduced from the power supply voltage to a first voltage to turn-on the second transistor, wherein the first voltage equals a summation of a threshold voltage of the second transistor and the second reference voltage.

17 . A discharge method, comprising:

providing a first subcircuit to receive a power supply voltage;

enabling the first subcircuit to provide a first discharge path between the power supply voltage and the first reference voltage;

generating a discharge control signal by the first subcircuit;

providing a second subcircuit to receive the power supply voltage and the discharge control signal; and

providing a second discharge path between the power supply voltage and a second reference voltage according to the discharge control signal by the second sub-circuit,

wherein the first subcircuit comprises:

a first transistor, having a first end receiving the power supply voltage and a control end receiving a bias voltage; and

a first resistor, coupled between a second end of the first transistor and a first reference voltage,

wherein a connection end between the second end of the first transistor and a first end of the first resistor generates the discharge control signal.

18 . The discharge method according to claim 17 , further comprising:

activating the first discharge path at a first time point by the first sub-circuit; and

activating the second discharge path at a second time point after the first time point by the second subcircuit.

19 . The discharge method according to claim 18 , further comprising:

discharging the power supply voltage by the first discharge path and the second discharge path after the second time point to a third time point.