Gate driver and display device including the same
A gate driver includes a stage configured to output a gate signal, the stage including an input part configured to control a voltage of a first node and a voltage of a second node based on signals supplied to a first input terminal and a second input terminal, an output part configured to supply a voltage of a first power source or a voltage of a second power source as the gate signal to an output terminal based on a voltage of a third node and a voltage of a fourth node, a first signal processing part configured to supply the voltage of the second power source to the fourth node based on the voltage of the first node, or to electrically connect the second node and the fourth node through a fifth node based on a signal supplied to a third input terminal, and a second signal processing part including a first transistor connected between the third node and a sixth node to control the voltage of the third node based on an operation of the first transistor.
1. A gate driver comprising a stage configured to output a gate signal, the stage comprising:
a first input terminal configured to receive an output signal of a previous stage or a start pulse;
a second input terminal configured to receive a first clock signal;
a third input terminal configured to receive a second clock signal that is shifted from the first clock signal;
a first power source;
a second power source;
an input part comprising a fourth transistor and configured to control a voltage of a first node and a voltage of a second node based on signals supplied to the first input terminal and the second input terminal, wherein the fourth transistor is connected between the first input terminal and the first node and comprises a gate electrode connected to the second input terminal;
an output part comprising a seventh transistor and an eighth transistor and configured to supply a voltage of the first power source or a voltage of the second power source as the gate signal to an output terminal based on a voltage of a third node and a voltage of a fourth node, wherein the seventh transistor is connected between the first power source and the output terminal and comprises a gate electrode connected to the third node, and wherein the eighth transistor is connected between the second power source and the output terminal and comprises a gate electrode connected to the fourth node;
a first signal processing part comprising an eleventh transistor and configured to supply the voltage of the second power source to the fourth node based on the voltage of the first node, or to electrically connect the second node and the fourth node through a fifth node based on a signal supplied to the third input terminal, wherein the eleventh transistor is connected between the second power source and the fourth node and comprises a gate electrode connected to the first node; and
a second signal processing part comprising a first transistor that is diode-connected between the third node and a sixth node, and that comprises a gate electrode coupled to the sixth node, to control the voltage of the third node based on an operation of the first transistor.
2. The gate driver of claim 1 , wherein the second signal processing part further comprises:
a second transistor connected between the first input terminal and the sixth node, and comprising a gate electrode connected to the second input terminal;
a third transistor connected between the third input terminal and a seventh node, and comprising a gate electrode connected to the sixth node; and
a first capacitor connected between the sixth node and the seventh node.
3. The gate driver of claim 2 , wherein the second signal processing part further comprises a fourteenth transistor connected between the second transistor and the sixth node, and comprising a gate electrode configured to receive the voltage of the first power source.
4. The gate driver of claim 2 , wherein the second signal processing part comprises a fifteenth transistor connected between the second power source and the seventh node, and comprising a gate electrode connected to the second node.
5. The gate driver of claim 1 , wherein the second signal processing part further comprises:
a second transistor connected between the first node and the sixth node;
a third transistor connected between the third input terminal and a seventh node, and comprising a gate electrode connected to the sixth node; and
a first capacitor connected between the sixth node and the seventh node.
6. The gate driver of claim 5 , wherein the second signal processing part further comprises a fifteenth transistor connected between the second power source and the seventh node, and comprising a gate electrode connected to the second node.
7. The gate driver of claim 1 , wherein the stage further comprises a stabilizing part electrically connected between the input part and the output part, and configured to limit a voltage drop amount of the first node and a voltage drop amount of the second node.
8. The gate driver of claim 7 , wherein the stabilizing part comprises:
a twelfth transistor connected between the first node and the third node, and comprising a gate electrode for receiving the voltage of the first power source; and
a thirteenth transistor connected between the second node and the fifth node, and comprising a gate electrode for receiving the voltage of the first power source.
9. The gate driver of claim 1 , wherein the stage further comprises an initializing part configured to supply the voltage of the second power source to the first node during an initializing period.
10. The gate driver of claim 9 , wherein the initializing part comprises a nineteenth transistor and a twentieth transistor connected in series between the second power source and the first node,
wherein the nineteenth transistor comprises a gate electrode connected to the second node, and
wherein the twentieth transistor comprises a gate electrode connected to the third input terminal.
11. The gate driver of claim 9 , wherein the initializing part comprises a sixteenth transistor connected between the second power source and the first node, and comprising a gate electrode for receiving a reset signal.
12. The gate driver of claim 9 , wherein the gate driver is configured to substantially simultaneously output the gate signal having a high level to all of gate lines during the initializing period.
13. The gate driver of claim 1 , wherein the input part further comprises;
a fifth transistor connected between the second input terminal and the second node, and comprising a gate electrode connected to the first node; and
a sixth transistor connected between the first power source and the second node, and comprising a gate electrode connected to the second input terminal.
14. The gate driver of claim 1 , wherein the first transistor is configured to convert a voltage of the sixth node having a form similar to an AC voltage into a form of a DC voltage as the voltage of the third node.
15. The gate driver of claim 1 , wherein the output part further comprises:
a seventeenth transistor connected between the first node and an eighth node, and comprising a gate electrode connected to the first power source;
an eighteenth transistor connected between the first power source and the output terminal, and comprising a gate electrode connected to the eighth node; and
a fourth capacitor connected between the eighth node and the output terminal.
16. The gate driver of claim 15 , wherein the output part controls a voltage drop amount of the gate signal by using coupling of the fourth capacitor according to a voltage change of the output terminal.
17. The gate driver of claim 1 , wherein the first signal processing part further comprises:
a second capacitor comprising a first terminal connected to the fifth node;
a ninth transistor connected between a second terminal of the second capacitor and the fourth node, and comprising a gate electrode connected to the third input terminal;
a tenth transistor connected between the second terminal of the second capacitor and the third input terminal, and comprising a gate electrode connected to the fifth node;
and
a third capacitor connected between the second power source and the fourth node.
18. A display device comprising:
pixels;
a scan driver comprising scan stages to supply a scan signal to the pixels through scan lines;
a data driver configured to supply data signals to the pixels through data lines; and
an emission driver comprising emission control stages to supply an emission control signal to the pixels through emission control lines,
wherein at least one of the scan stages or the emission control stages comprises:
a first input terminal configured to receive an output signal of a previous stage or a start pulse;
a second input terminal configured to receive a first clock signal;
a third input terminal configured to receive a second clock signal that is shifted from the first clock signal;
a first power source;
a second power source;
an input part comprising a fourth transistor and configured to control a voltage of a first node and a voltage of a second node based on signals supplied to the first input terminal and the first clock signal supplied to the second input terminal;
an output part comprising a seventh transistor and an eighth transistor and configured to supply a voltage of the first power source or a voltage of the second power source as the scan signal or the emission control signal to an output terminal based on a voltage of a third node and a voltage of a fourth node, wherein the seventh transistor is connected between the first power source and the output terminal and comprises a gate electrode connected to the third node, and wherein the eighth transistor is connected between the second power source and the output terminal and comprises a gate electrode connected to the fourth node;
a first signal processing part comprising an eleventh transistor and configured to supply the voltage of the second power source to the fourth node based on the voltage of the first node, or to electrically connect the second node and the fourth node through a fifth node based on the second clock signal supplied to the third input terminal, wherein the eleventh transistor is connected between the second power source and the fourth node and comprises a gate electrode connected to the first node; and
a second signal processing part comprising a first transistor that is diode-connected between the third node and a sixth node, and that comprises a gate electrode coupled to the sixth node, to control the voltage of the third node based on an operation of the first transistor.
19. The display device of claim 18 , wherein the second signal processing part further comprises:
a second transistor connected between the first input terminal and the sixth node, and comprising a gate electrode connected to the second input terminal;
a third transistor connected between the third input terminal and a seventh node and comprising a gate electrode connected to the sixth node; and
a first capacitor connected between the sixth node and the seventh node.