# US 9,437,324 B2 · Shift register unit, driving method thereof, shift register and display device

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 9,437,324 B2
- Document ID: US9437324B2
- Status: Granted
- Kind: B2
- Application number: 14/359,856
- Filed: 2013-11-21
- Published: 2015-02-12
- Granted: 2016-09-06
- Earliest claimed: 2013-08-09
- Assignees: Boe Technology Group Co., Ltd.; Chengdu Boe Optoelectronics Technology Co., Ltd.
- Applicants: Boe Technology Group Co., Ltd.; Chengdu Boe Optoelectronics Technology Co., Ltd.
- Inventors: Wen Tan; Xiaojing Qi
- Web page: https://patentgrep.com/patent/US9437324B2

## CPC

- G11C 19/184: {with field-effect transistors, e.g. MOS-FET}
- G11C 19/28: using semiconductor elements (G11C19/14, G11C19/36 take precedence)
- G09G 3/3266: Details of drivers for scan electrodes
- G09G 2310/0286: Details of a shift registers arranged for use in a driving circuit
- G11C: STATIC STORES (semiconductor memory devices H10B)
- G09G: ARRANGEMENTS OR CIRCUITS FOR CONTROL OF INDICATING DEVICES USING STATIC MEANS TO PRESENT VARIABLE INFORMATION (arrangements for transferring data between digital computers and displays G06F3/14; static indicating arrangements comprising an association of a number of separate sources or light control cells G09F9/00; static indicating arrangements comprising integral associations of a number of light sources H01J, H01K, H10H, H05B33/12; scanning, transmission or reproduction of documents or the like, e.g. facsimile transmission, details thereof H04N1/00)

## Abstract

Embodiments of the present invention provides a shift register unit, driving method thereof, a shift register and a display device. A switch-off module is provided to disconnect electrical connections between a pull-up node and a precharge module and between the pull-up node and a pull-down module at a pull-up stage. As a result, it is able to prevent excessive electric leakage of a GOA circuit, thereby to improve the reliability and power consumption of the GOA circuit with an Oxide TFT.

## Claims

### Claim 1

A shift register unit comprising a first capacitor, a pull-up module, a precharge module and a pull-down module, a first end of the first capacitor being coupled to the pull-up module at a pull-up node, the shift register unit further comprising:
a switch-off module coupled to the pull-up node and to a first node located between the precharge module and the pull-down module, configured to disconnect electrical connections (i) between the pull-up node and the precharge module and (ii) between the pull-up node and the pull-down module at a pull-up stage,
wherein the switch-off module comprises:
a first TFT, a source electrode of the first TFT is coupled to the first node, a gate electrode of the first TFT is coupled to a second clock signal input, and a drain electrode of the first TFT is coupled to the pull-up node; and
a switch-off controlling unit configured to control a source voltage of the first TFT at the pull-up stage so as to enable the first TFT to be in a fully off state, thereby to disconnect the electrical connections (i) between the pull-up node and the precharge module and (ii) between the pull-up node and the pull-down module.

### Claim 2 (depends on 1)

The shift register unit according to claim 1, wherein the switch-off controlling unit comprises:
a feedback capacitor, a first end of the feedback capacitor is coupled to the source electrode of the first TFT, and a second end of the feedback capacitor is coupled to the pull-up module and the pull-down module.

### Claim 3 (depends on 1)

The shift register unit according to claim 1, wherein the switch-off controlling unit further comprises:
a second TFT, a source electrode of the second TFT is coupled to the pull-up module and the pull-down module, a gate electrode of second TFT is coupled to a first clock signal input, and a drain electrode of second TFT is coupled to the source electrode of the first TFT.

### Claim 4 (depends on 1)

The shift register unit according to claim 1, wherein the switch-off controlling unit further comprises:
a second TFT, a source electrode of second TFT is coupled to the pull-up module and the pull-down module, a gate electrode of second TFT is coupled to the source electrode of the second TFT, and a drain electrode of second TFT is coupled to the source electrode of the first TFT.

### Claim 5 (depends on 1)

The shift register unit according to claim 1, wherein the switch-off controlling unit comprises a second TFT, and the switch-off module further comprises a third TFT,
the source electrode of the first TFT is coupled to a drain electrode of the second TFT and a drain electrode of the third TFT
a source electrode of the second TFT is coupled to the pull-up module and the pull-down module, and a gate electrode of the second TFT is coupled to a first clock signal input; and
a source electrode of the third TFT is coupled to the first node, and a gate electrode of the third TFT is coupled to the second clock signal input.

### Claim 6 (depends on 1)

The shift register unit according to claim 1, wherein the pull-up module comprises:
a fourth TFT, a source electrode of the fourth TFT is coupled to a first clock signal input, a gate electrode of the fourth TFT is coupled to the pull-up node, and a drain electrode of the fourth TFT is coupled to a second end of the first capacitor, the pull-down module and a signal output.

### Claim 7 (depends on 1)

The shift register unit according to claim 1, wherein the pull-up module comprises:
a fourth TFT and a fifth TFT,
wherein:
a source electrode of the fourth TFT is coupled to a source electrode of the fifth TFT and a first clock signal input;
a gate electrode of the fourth TFT is coupled to a gate electrode of the fifth TFT and the pull-up node;
a drain electrode of the fourth TFT is coupled to a gate signal output, a second end of the first capacitor and the pull-down module; and
a drain electrode of the fifth TFT is coupled to the switch-off module, the pull-down module and a start signal output.

### Claim 8 (depends on 1)

The shift register unit according to claim 1, wherein the precharge module comprises:
a sixth TFT, a source electrode and a gate electrode of the sixth TFT are coupled to a start signal input, and a drain electrode of the sixth TFT is coupled to the switch-off module and the pull-down module.

### Claim 9 (depends on 1)

The shift register unit according to claim 1, wherein the pull-down module comprises:
a seventh TFT, an eighth TFT, a ninth TFT, and a pull-down controlling unit configured to control an on or off state of the seventh, eighth and ninth TFTs,
wherein:
a source electrode of the seventh TFT is coupled to the precharge module and the switch-off module, a gate electrode of the seventh TFT is coupled to the pull-down controlling unit, a gate electrode of the eighth TFT and a gate electrode of the ninth TFT at a pull-down node, and a drain electrode of the seventh TFT is coupled to a first level signal input;
a source electrode of the eighth TFT is coupled to the pull-up module, the switch-off module and a start signal output, and a drain electrode of the eighth TFT is coupled to the first level signal input; and
a source electrode of the ninth TFT is coupled to the pull-up module, a second end of the first capacitor, and a gate signal output, and a drain electrode of the ninth TFT is coupled to a second level signal input.

### Claim 10 (depends on 9)

The shift register unit according to claim 9, wherein a potential of an input signal from the second level signal input is less than 0 and greater than a potential of an input signal from the first level signal input.

### Claim 11 (depends on 9)

The shift register unit according to claim 9, wherein the pull-down controlling unit comprises a tenth TFT and an eleventh TFT, wherein:
a source electrode and a gate electrode of the tenth TFT are coupled to the second clock signal input, and a drain electrode of the tenth TFT is coupled to the pull-down node, and
a drain electrode of the eleventh TFT is coupled to the pull-down node, a gate electrode of the eleventh TFT is coupled to a start signal input, and a source electrode of the eleventh TFT is coupled to the first level signal input.

### Claim 12 (depends on 9)

The shift register unit according to claim 9, wherein the pull-down controlling unit comprises a third capacitor and a tenth TFT, wherein:
a first end of the third capacitor is coupled to the second clock signal input, and a second end of the third capacitor is coupled to the pull-down node, and
a drain electrode of the tenth TFT is coupled to the pull-down node, a gate electrode of the tenth TFT is coupled to a start signal input, and a source electrode of the tenth TFT is coupled to the first level signal input.

### Claim 13 (depends on 9)

The shift register unit according to claim 9, wherein the pull-down controlling unit comprises a tenth TFT, an eleventh TFT, a twelfth TFT and a thirteenth TFT, wherein:
a source electrode and a gate electrode of the tenth TFT are coupled to the second clock signal input, and a drain electrode of the tenth TFT is coupled to a gate electrode of the eleventh TFT and a drain electrode of the twelfth TFT,
a source electrode of the eleventh TFT is coupled to the second clock signal input, and a drain electrode of the eleventh TFT is coupled to the pull-down node,
a gate electrode of the twelfth TFT is coupled to a start signal input and a gate electrode of the thirteenth TFT, and a source electrode of the twelfth TFT is coupled to the first level signal input and a source electrode of the thirteenth TFT, and
a drain electrode of the thirteenth TFT is coupled to the pull-down node.

### Claim 14 (depends on 1)

A method for driving the shift register unit according to claim 1, the method comprising:
at a precharge stage, pulling up a pull-up node and a first node to a first potential, and enabling a switch-off module to be in an on state;
at a pull-up stage, pulling up the pull-up node and the first node to a second potential greater than the first potential, enabling the switch-off module to be in a fully off state, and disconnecting electrical connections between the pull-up node and a precharge module and between the pull-up node and a pull-down module;
at a resetting stage, enabling the switch-off module to be in the on state, and pulling down the pull-up node and the first node to a third potential less than the first potential; and
at a resetting-maintaining stage, enabling the switch-off module to be in the off state, and maintaining the pull-up node and the first node at the third potential.

### Claim 15 (depends on 14)

The method according to claim 14, wherein:
at the precharge stage, a low level signal is input by a first clock signal input, a high level signal is input by the second clock signal input, and a high level signal is input by a start signal input;
at the pull-up stage, a high level signal is input by the first clock signal input, a low level signal is input by the second clock signal input, and a low level signal is input by the start signal input;
at the resetting stage, a low level signal is input by the first clock signal input, a high level signal is input by the second clock signal input, and a low level signal is input by the start signal input; and
at the resetting-maintaining stage, a high level signal is input by the first clock signal input, a low level signal is input by the second clock signal input, and a low level signal is input by the start signal input.

### Claim 16 (depends on 1)

A display device, comprising multi-levels of shift register unit according to claim 1.

### Claim 17

A shift register unit comprising: a first capacitor, a pull-up module, a precharge module, and a pull-down module, a first end of the first capacitor being coupled to the pull-up module at a pull-up node, the shift register unit further comprising:
a switch-off module coupled to the pull-up node and to a first node located between the precharge module and the pull-down module, configured to disconnect electrical connections (i) between the pull-up node and the precharge module and (ii) between the pull-up node and the pull-down module at a pull-up stage;
wherein the switch-off module comprises:
a first TFT, a second TFT, and a third TFT,
wherein:
a source electrode of the first TFT is coupled to a drain electrode of the second TFT and a drain electrode of the third TFT, a gate electrode of the first TFT is coupled to a second clock signal input, and a drain electrode of the first TFT is coupled to the pull-up node;
a source electrode of the second TFT is coupled to the pull-up module and the pull-down module, and a gate electrode of the second TFT is coupled to a first clock signal input; and
a source electrode of the third TFT is coupled to the first node, and a gate electrode of the third TFT is coupled to the second clock signal input.