Shift register, method for controlling the same, gate driving circuit and display apparatus

Patent metadata

Field	Value
Publication number	US-10885999-B2
Application number	US-201816120869-A
Country	US
Kind code	B2
Filing date	Sep 4, 2018
Priority date	Jan 8, 2018
Publication date	Jan 5, 2021
Grant date	Jan 5, 2021

Abstract

The embodiments of the present application provide a shift register, a method for controlling the same, a gate driving circuit, and a display apparatus. The shift register includes: an input circuit coupled to a signal input terminal and a pull-up node; a pull-up circuit coupled to the pull-up node, a first clock signal terminal and a signal output terminal; a pull-down circuit coupled to a reset signal terminal, a first voltage signal terminal, the pull-up node, and the signal output terminal; a pull-down control circuit coupled to a second clock signal terminal, the pull-up node, a pull-down node, and the first voltage signal terminal; a first de-noising circuit coupled to the pull-up node, the signal input terminal, the first voltage signal terminal, and a compensation node; and a compensation circuit coupled to the first clock signal terminal, the second clock signal terminal, and the compensation node.

First claim

We claim:

1. A shift register, comprising:
an input circuit coupled electronically to a signal input terminal and a pull-up node, and configured to apply a voltage at the signal input terminal to the pull-up node under a control of an input signal provided by the signal input terminal;
a pull-up circuit coupled electronically to the pull-up node, a first clock signal terminal and a signal output terminal, and configured to apply a voltage at the first clock signal terminal to the signal output terminal under a control of a voltage at the pull-up node;
a pull-down circuit coupled electronically to a reset signal terminal, a first voltage signal terminal, the pull-up node, and the signal output terminal, and configured to apply a voltage at the first voltage signal terminal to the signal output terminal and the pull-up node under a control of a voltage at the reset signal terminal;
a pull-down control circuit coupled electronically to a second clock signal terminal, the pull-up node, a pull-down node, and the first voltage signal terminal, and configured to apply a voltage at the second clock signal terminal to the pull-down node under a control of a clock signal provided by the second clock signal terminal, and apply the voltage at the first voltage signal terminal to the pull-down node under the control of the voltage at the pull-up node;
a first de-noising circuit coupled electronically to the pull-up node, the signal input terminal, the first voltage signal terminal, the output signal terminal, and a compensation node, and configured to perform de-noising processing on an output signal at the signal output terminal; and
a compensation circuit coupled electronically to the first clock signal terminal, the second clock signal terminal, the compensation node, and the first voltage signal terminal, and configured to simulate a drift of a threshold voltage for a transistor in the first de-noising circuit according to clock signals provided by the first clock signal terminal and the second clock signal terminal, so as to compensate for the threshold voltage of the transistor;
the compensation circuit comprises:
a fourth transistor having a control electrode and a first electrode coupled electronically to the compensation node, and a second electrode coupled electronically to the second clock signal terminal;
a second capacitor having a first terminal coupled electronically to the compensation node, and a second terminal coupled electronically to the second clock signal terminal;
a fifth transistor having a control electrode and a first electrode coupled electronically to the first clock signal terminal, and a second electrode coupled electronically to the compensation node; and
a sixth transistor having a control electrode coupled electronically to the first clock signal terminal, a first electrode coupled electronically to the first voltage signal terminal, and a second electrode coupled electronically to the second clock signal terminal.

2. The shift register according to claim 1 , further comprising:
a second de-noising circuit coupled electronically to the pull-down node, the pull-up node, the first voltage signal terminal, and the signal output terminal, and configured to de-noise the output signal at the signal output terminal according to the voltage at the pull-up node under a control of a voltage at the pull-down node.

3. The shift register according to claim 1 , wherein the pull-up circuit comprises:
a first transistor having a control electrode coupled electronically to the pull-up node, a first electrode coupled electronically to the signal output terminal, and a second electrode coupled electronically to the first clock signal terminal; and
a first capacitor having a first terminal coupled electronically to the pull-up node, and a second terminal coupled electronically to the signal output terminal.

4. The shift register according to claim 1 , wherein the first de-noising circuit comprises:
a second transistor having a control electrode coupled electronically to the compensation node, a first electrode coupled electronically to the first voltage signal terminal, and a second electrode coupled electronically to the signal output terminal; and
a third transistor having a control electrode coupled electronically to the compensation node, a first electrode coupled electronically to the pull-up node, and a second electrode coupled electronically to the signal input terminal.

5. The shift register according to claim 4 , wherein channel width to length ratios of the fourth transistor, the fifth transistor, and the sixth transistor are defined so that the voltage at the compensation node is greater than a threshold voltage of the second transistor and a threshold voltage of the third transistor in the first de-noising circuit while the second capacitor being charged.

6. The shift register according to claim 2 , wherein the second de-noising circuit comprises:
a seventh transistor having a control electrode coupled electronically to the pull-down node, a first electrode coupled electronically to the first voltage signal terminal, and a second electrode coupled electronically to the signal output terminal; and
an eighth transistor having a control electrode coupled electronically to the pull-down node, a first electrode coupled electronically to the first voltage signal terminal, and a second electrode coupled electronically to the pull-up node.

7. The shift register according to claim 1 , wherein the pull-down control circuit comprises:
a ninth transistor having a control electrode and a first electrode both coupled electronically to the second clock signal terminal, and a second electrode coupled electronically to pull-down control node;
a tenth transistor having a control electrode coupled electronically to the pull-down control node, a first electrode coupled electronically to the second clock signal terminal, and a second electrode coupled electronically to the pull-down node;
an eleventh transistor having a control electrode coupled electronically to the pull-up node, a first electrode coupled electronically to the first voltage signal terminal, and a second electrode coupled electronically to the pull-down node; and
a twelfth transistor having a control electrode coupled electronically to the pull-up node, a first electrode coupled electronically to the first voltage signal terminal, and a second electrode coupled electronically to the pull-down control node.

8. The shift register according to claim 1 , wherein the pull-down circuit comprises:
a thirteenth transistor having a control electrode coupled electronically to the reset signal terminal, a first electrode coupled electronically to the first voltage signal terminal, and a second electrode coupled electronically to the signal output terminal; and
a fourteenth transistor having a control electrode coupled electronically to the reset signal terminal, a first electrode coupled electronically to the first voltage signal terminal, and a second electrode coupled electronically to the pull-up node.

9. The shift register according to claim 1 , wherein the input circuit comprises:
a fifteenth transistor having a control electrode coupled electronically to the signal input terminal, a first electrode coupled electronically to the pull-up node, and a second electrode coupled electronically to the control electrode of the fifteenth transistor.

10. A gate driving circuit, comprising the shift register according to claim 1 .

11. A display apparatus, comprising the gate driving circuit according to claim 10 .

12. A method for controlling the shift register according to claim 1 , comprising:
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Assignees

• Boe Technology Group Co Ltd
• Hefei Xinsheng Optoelectronics Technology Co Ltd

Inventors

• Qian Xianrui
• Chen Yuting
• Li Fei
• Li Bo

Classifications

• G09G2300/0809

  Several active elements per pixel in active matrix panels · CPC title

• G09G2320/0233

  Improving the luminance or brightness uniformity across the screen · CPC title

• G11C19/28 Primary

  using semiconductor elements (G11C19/14, G11C19/36 take precedence) · CPC title

• G09G3/20 Primary

  for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix {no fixed position being assigned to or needed to be assigned to the individual characters or partial characters} · CPC title

• G09G3/3677

  suitable for active matrices only · CPC title