SELF-COMPENSATING GATE DRIVING CIRCUIT

• US 20160260403A1
• Filed: 08/14/2014
• Published: 09/08/2016
• Est. Priority Date: 07/17/2014
• Status: Active Grant

• Current Assignee: Shenzhen China Star Optoelectronics Technology Co., Ltd. (TCL Technology Group Corp.)
• Original Assignee: Shenzhen China Star Optoelectronics Technology Co., Ltd. (TCL Technology Group Corp.)
• Inventors: DAI, Chao
• Granted Patent: US 9,524,688 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G09G 2300/0408 Integration of the drivers onto the display substrate
• CPC Class Codes: G09G 2310/0289 Details of voltage level shifters arranged for use in a driving circuit
• CPC Class Codes: G09G 2310/08 Details of timing specific for flat panels, other than clock recovery
• CPC Class Codes: G09G 3/36 using liquid crystals
• CPC Class Codes: G09G 3/3648 using an active matrix G09G3/367 - G09G3/3696 take precedence
• CPC Class Codes: G09G 3/3677 suitable for active matrices only
• CPC Class Codes: G09G 3/3696 Generation of voltages supplied to electrode drivers

Abstract

The present invention provides a self-compensating gate driving circuit, comprising: a plurality of GOA units which are cascade connected, and a Nth GOA unit controls charge to a Nth horizontal scanning line G(n) in a display area, and the Nth GOA unit controls charge to a Nth horizontal scanning line G(n) in a display area, and the Nth GOA unit comprises a pull-up controlling part, a pull-up part, a transmission part, a first pull-down part, a bootstrap capacitor part and a pull-down holding part; the pull-up part, the first pull-down part, the bootstrap capacitor part and the pull-down holding circuit are respectively coupled to a Nth gate signal point Q(N) and the Nth horizontal scanning line G(n), and the pull-up controlling part and the transmission part are respectively coupled to the Nth gate signal point Q(N), and the pull-down holding part is inputted with a DC low voltage VSS; the pull-down holding part comprises a first pull-down holding part and a second pull-down holding part to alternately work. The present invention is designed to have the pull-down holding part with self-compensating function to promote the reliability of the long term operation for the gate driving circuit. The influence of the threshold voltage drift to the operation of the gate driving circuit is diminished.

Claims

1. A self-compensating gate driving circuit, comprising:

a plurality of gate driver on array units which are cascade connected, and a Nth gate driver on array unit controls charge to a Nth horizontal scanning line in a display area, and the Nth gate driver on array unit comprises a pull-up controlling part, a pull-up part, a transmission part, a first pull-down part, a bootstrap capacitor part and a pull-down holding part;

the pull-up part, the first pull-down part, the bootstrap capacitor part and the pull-down holding circuit are respectively coupled to a Nth gate signal point and the Nth horizontal scanning line, and the pull-up controlling part and the transmission part are respectively coupled to the Nth gate signal point, and the pull-down holding part is inputted with a DC low voltage;

the pull-down holding part comprises a first pull-down holding part and a second pull-down holding part to alternately work;

the first pull-down holding part comprises;

a first thin film transistor, and a gate of the first thin film transistor is electrically coupled to the first circuit point, and a drain is electrically coupled to the Nth horizontal scanning line, and a source is inputted with the DC low voltage;

a second thin film transistor, and a gate of the second thin film transistor is electrically coupled to the first circuit point, and a drain is electrically coupled to the Nth gate signal point, and a source is inputted with the DC low voltage;

a third thin film transistor, and a gate of the third thin film transistor is electrically coupled to a first low frequency clock or a first high frequency clock, and a drain is electrically coupled to a first low frequency clock or a first high frequency clock, and a source is electrically coupled to a second circuit point;

a fourth thin film transistor, and a gate of the fourth thin film transistor is electrically coupled to the Nth gate signal point, and a drain is electrically coupled to the second circuit point, and a source is inputted with the DC low voltage;

a fifth thin film transistor, and a gate of the fifth thin film transistor is electrically coupled to a N−

1 th gate signal point, a drain is electrically coupled to the first circuit point, and a source is inputted with the DC low voltage;

a sixth thin film transistor, and a gate of the sixth thin film transistor is electrically coupled to a N+1 th horizontal scan line, and a drain is electrically coupled to the first circuit point, and a source is electrically coupled to the Nth gate signal point;

a seventh thin film transistor, and a gate of the seventh thin film transistor is electrically coupled to a second low frequency clock or a second high frequency clock, and a drain is a first low frequency clock or a first high frequency clock, and a source is electrically coupled to the second circuit point;

a first capacitor, and an upper electrode plate of the first capacitor is electrically coupled to the second circuit point and a lower electrode plate of the first capacitor is electrically coupled to the first circuit point;

the second pull-down holding part comprises;

an eighth thin film transistor, and a gate of the eighth thin film transistor is electrically coupled to the third circuit point, and a drain is electrically coupled to the Nth horizontal scanning line, and a source is inputted with the DC low voltage;

a ninth thin film transistor, and a gate of the ninth thin film transistor is electrically coupled to the third circuit point, and a drain is electrically coupled to the Nth gate signal point, and a source is inputted with the DC low voltage;

a tenth thin film transistor, and a gate of the tenth thin film transistor is electrically coupled to a second low frequency clock or a second high frequency clock, and a drain is electrically coupled to a second low frequency clock or a second high frequency clock, and a source is electrically coupled to a fourth circuit point;

an eleventh thin film transistor, and a gate of the eleventh thin film transistor is electrically coupled to the Nth gate signal point, and a drain is electrically coupled to the fourth circuit point, and a source is inputted with the DC low voltage;

a twelfth thin film transistor, and a gate of the twelfth thin film transistor is electrically coupled to a N−

1 th gate signal point, a drain is electrically coupled to the third circuit point, and a source is inputted with the DC low voltage;

a thirteenth thin film transistor, and a gate of the thirteenth thin film transistor is electrically coupled to a N+1 th horizontal scan line, and a drain is electrically coupled to the third circuit point, and a source is electrically coupled to the Nth gate signal point;

a fourteenth thin film transistor, and a gate of the fourteenth thin film transistor is electrically coupled to a first low frequency clock or a first high frequency clock, and a drain is a second low frequency clock or a second high frequency clock, and a source is electrically coupled to the fourth circuit point;

a second capacitor, and an upper electrode plate of the second capacitor is electrically coupled to the fourth circuit point and a lower electrode plate of the second capacitor is electrically coupled to the third circuit point.

2. The self-compensating gate driving circuit according to claim 1, wherein the pull-up controlling part comprises:

a fifteenth thin film transistor, and a gate of the fifteenth thin film transistor is inputted with a transmission signal from a N−

1 th gate driver on array unit, and a drain is electrically coupled to a N−

1 th horizontal scan line, and a source is electrically coupled to the Nth gate signal point;

the pull-up part comprises a sixteenth thin film transistor, and a gate of the sixteenth thin film transistor is electrically coupled to the Nth gate signal point, and a drain is inputted with a first high frequency clock or a second high frequency clock, and a source is electrically coupled to the Nth horizontal scan line;

the transmission part comprises a seventeenth thin film transistor, and a gate of the seventeenth thin film transistor is electrically coupled to the Nth gate signal point, and a drain is inputted with the first high frequency clock or the second high frequency clock, and a source outputs a Nth transmission signal;

the first pull-down part comprises an eighteenth thin film transistor, and a gate of the eighteenth thin film transistor is electrically coupled to a N+2 th horizontal scan line, and a drain is electrically coupled to the Nth horizontal scan line, and a source is inputted with the DC low voltage;

a nineteenth thin film transistor, and a gate of the nineteenth thin film transistor is electrically coupled to the N+2 th horizontal scan line, and a drain is electrically coupled to the Nth gate signal point, and a source is inputted with the DC low voltage;

the bootstrap capacitor part comprises a bootstrap capacitor.

3. The self-compensating gate driving circuit according to claim 2, wherein in the first level connection, the gate of the fifth thin film transistor is electrically coupled to a circuit activation signal;

the gate of the twelfth thin film transistor is electrically coupled to the circuit activation signal;

the gate and the drain of the fifteenth thin film transistor are both electrically coupled to the circuit activation signal.

4. The self-compensating gate driving circuit according to claim 2, wherein in the last level connection, the gate of the sixth thin film transistor is electrically coupled to a circuit activation signal;

the gate of the thirteenth thin film transistor is electrically coupled to the circuit activation signal;

the gate of the eighteenth thin film transistor is electrically coupled to the 2 th horizontal scan line;

the gate of the nineteenth thin film transistor is electrically coupled to the 2 th horizontal scan line.

5. The self-compensating gate driving circuit according to claim 1, wherein the pull-down holding part further comprises a third capacitor, and an upper electrode plate of the third capacitor is electrically coupled to the first circuit point, and a lower electrode plate of the third capacitor is inputted with the DC low voltage;

circuit structures of the first pull-down holding part and the second pull-down holding part are the same.

6. The self-compensating gate driving circuit according to claim 1, wherein the first pull-down holding part further comprises a twentieth thin film transistor, and a gate of the twelfth thin film transistor is electrically coupled to the N+1 th horizontal scan line, and a drain is electrically coupled to the second circuit point, and a source is inputted with the DC low voltage;

circuit structures of the first pull-down holding part and the second pull-down holding part are the same.

7. The self-compensating gate driving circuit according to claim 1, wherein the pull-down holding part further comprises a third capacitor, and an upper electrode plate of the third capacitor is electrically coupled to the first circuit point, and a lower electrode plate of the third capacitor is electrically coupled to the DC low voltage;

a twentieth thin film transistor, and a gate of the twentieth thin film transistor is electrically coupled to the N+1 th horizontal scan line, and a drain is electrically coupled to the second circuit point, and a source is inputted with the DC low voltage;

circuit structures of the first pull-down holding part and the second pull-down holding part are the same.

8. The self-compensating gate driving circuit according to claim 2, wherein the first high frequency clock and the second high frequency clock are two high frequency clocks that phases are completely opposite;

the first low frequency clock and the second low frequency clock are two low frequency clocks that phases are completely opposite.

9. The self-compensating gate driving circuit according to claim 2, wherein in the first pull-down part, the gate of the eighteenth thin film transistor and the gate of the nineteenth thin film transistor are both electrically coupled to the N+2 th horizontal scan line mainly for realizing three stages of a voltage level of the Nth gate signal point, and in the first stage, the voltage level is raised to a high voltage level and kept for a certain period, and in the second stage, the voltage level is raised to another high voltage level and kept for another certain period based on the first stage, and in the third stage, the voltage level is dropped to the high voltage level of the first stage to be hold based on the second stage, and then self-compensation of the threshold voltage is implemented in the third stage.

10. The self-compensating gate driving circuit according to claim 9, wherein the voltage level of the Nth gate signal point has the three stages, and a variation of the voltage level in the third stage is mainly influenced by the sixth thin film transistor or the thirteenth thin film transistor.

11. A self-compensating gate driving circuit, comprising:

a plurality of gate driver on array units which are cascade connected, and a Nth gate driver on array unit controls charge to a Nth horizontal scanning line in a display area, and the Nth gate driver on array unit comprises a pull-up controlling part, a pull-up part, a transmission part, a first pull-down part, a bootstrap capacitor part and a pull-down holding part;

the pull-up part, the first pull-down part, the bootstrap capacitor part and the pull-down holding circuit are respectively coupled to a Nth gate signal point and the Nth horizontal scanning line, and the pull-up controlling part and the transmission part are respectively coupled to the Nth gate signal point, and the pull-down holding part is inputted with a DC low voltage;

the pull-down holding part comprises a first pull-down holding part and a second pull-down holding part to alternately work;

the first pull-down holding part comprises;

a first thin film transistor, and a gate of the first thin film transistor is electrically coupled to the first circuit point, and a drain is electrically coupled to the Nth horizontal scanning line, and a source is inputted with the DC low voltage;

a second thin film transistor, and a gate of the second thin film transistor is electrically coupled to the first circuit point, and a drain is electrically coupled to the Nth gate signal point, and a source is inputted with the DC low voltage;

a third thin film transistor, and a gate is electrically coupled to a first low frequency clock or a first high frequency clock, and a drain is electrically coupled to a first low frequency clock or a first high frequency clock, and a source is electrically coupled to a second circuit point;

a fourth thin film transistor, and a gate of the fourth thin film transistor is electrically coupled to the Nth gate signal point, and a drain is electrically coupled to the second circuit point, and a source is inputted with the DC low voltage;

a fifth thin film transistor, and a gate of the fifth thin film transistor is electrically coupled to a N−

1 th gate signal point, a drain is electrically coupled to the first circuit point, and a source is inputted with the DC low voltage;

a sixth thin film transistor, and a gate of the sixth thin film transistor is electrically coupled to a N+1 th horizontal scan line, and a drain is electrically coupled to the first circuit point, and a source is electrically coupled to the Nth gate signal point;

a seventh thin film transistor, and a gate of the seventh thin film transistor is electrically coupled to a second low frequency clock or a second high frequency clock, and a drain is a first low frequency clock or a first high frequency clock, and a source is electrically coupled to the second circuit point;

a first capacitor, and an upper electrode plate of the first capacitor is electrically coupled to the second circuit point and a lower electrode plate of the first capacitor is electrically coupled to the first circuit point;

the second pull-down holding part comprises;

an eighth thin film transistor, and a gate of the eighth thin film transistor is electrically coupled to the third circuit point, and a drain is electrically coupled to the Nth horizontal scanning line, and a source is inputted with the DC low voltage;

a ninth thin film transistor, and a gate of the ninth thin film transistor is electrically coupled to the third circuit point, and a drain is electrically coupled to the Nth gate signal point, and a source is inputted with the DC low voltage;

a tenth thin film transistor, and a gate of the tenth thin film transistor is electrically coupled to a second low frequency clock or a second high frequency clock, and a drain is electrically coupled to a second low frequency clock or a second high frequency clock, and a source is electrically coupled to a fourth circuit point;

an eleventh thin film transistor, and a gate of the eleventh thin film transistor is electrically coupled to the Nth gate signal point, and a drain is electrically coupled to the fourth circuit point, and a source is inputted with the DC low voltage;

a twelfth thin film transistor, and a gate of the twelfth thin film transistor is electrically coupled to a N−

1 th gate signal point, a drain is electrically coupled to the third circuit point, and a source is inputted with the DC low voltage;

a thirteenth thin film transistor, and a gate of the thirteenth thin film transistor is electrically coupled to a N+1 th horizontal scan line, and a drain is electrically coupled to the third circuit point, and a source is electrically coupled to the Nth gate signal point;

a fourteenth thin film transistor, and a gate of the fourteenth thin film transistor is electrically coupled to a first low frequency clock or a first high frequency clock, and a drain is a second low frequency clock or a second high frequency clock, and a source is electrically coupled to the fourth circuit point;

a second capacitor, and an upper electrode plate of the second capacitor is electrically coupled to the fourth circuit point and a lower electrode plate of the second capacitor is electrically coupled to the third circuit point;

wherein the pull-up controlling part comprises;

a fifteenth thin film transistor, and a gate of the fifteenth thin film transistor is inputted with a transmission signal from a N−

1 th gate driver on array unit, and a drain is electrically coupled to a N−

1 th horizontal scan line, and a source is electrically coupled to the Nth gate signal point;

the pull-up part comprises a sixteenth thin film transistor, and a gate of the sixteenth thin film transistor is electrically coupled to the Nth gate signal point, and a drain is inputted with a first high frequency clock or a second high frequency clock, and a source is electrically coupled to the Nth horizontal scan line;

the transmission part comprises a seventeenth thin film transistor, and a gate of the seventeenth thin film transistor is electrically coupled to the Nth gate signal point, and a drain is inputted with the first high frequency clock or the second high frequency clock, and a source outputs a Nth transmission signal;

the first pull-down part comprises an eighteenth thin film transistor, and a gate of the eighteenth thin film transistor is electrically coupled to a N+2 th horizontal scan line, and a drain is electrically coupled to the Nth horizontal scan line, and a source is inputted with the DC low voltage;

a nineteenth thin film transistor, and a gate of the nineteenth thin film transistor is electrically coupled to the N+2 th horizontal scan line, and a drain is electrically coupled to the Nth gate signal point, and a source is inputted with the DC low voltage;

the bootstrap capacitor part comprises a bootstrap capacitor;

wherein in the first level connection, the gate of the fifth thin film transistor is electrically coupled to a circuit activation signal;

the gate of the twelfth thin film transistor is electrically coupled to the circuit activation signal;

the gate and the drain of the fifteenth thin film transistor are both electrically coupled to the circuit activation signal;

wherein in the last level connection, the gate of the sixth thin film transistor is electrically coupled to a circuit activation signal;

the gate of the thirteenth thin film transistor is electrically coupled to the circuit activation signal;

the gate of the eighteenth thin film transistor is electrically coupled to the 2 th horizontal scan line;

the gate of the nineteenth thin film transistor is electrically coupled to the 2 th horizontal scan line;

wherein the first high frequency clock and the second high frequency clock are two high frequency clocks that phases are completely opposite;

the first low frequency clock and the second low frequency clock are two low frequency clocks that phases are completely opposite;

wherein in the first pull-down part, the gate of the eighteenth thin film transistor and the gate of the nineteenth thin film transistor are both electrically coupled to the N+2 th horizontal scan line mainly for realizing three stages of a voltage level of the Nth gate signal point, and in the first stage, the voltage level is raised to a high voltage level and kept for a certain period, and in the second stage, the voltage level is raised to another high voltage level and kept for another certain period based on the first stage, and in the third stage, the voltage level is dropped to the high voltage level of the first stage to be hold based on the second stage, and then self-compensation of the threshold voltage is implemented in the third stage;

wherein the voltage level of the Nth gate signal point has the three stages, and a variation of the voltage level in the third stage is mainly influenced by the sixth thin film transistor or the thirteenth thin film transistor.