# US 10,311,787 B2 · Pixel driving circuit, driving method, pixel unit, and display apparatus

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

- Number: US 10,311,787 B2
- Document ID: US10311787B2
- Status: Granted
- Kind: B2
- Application number: 15/724,597
- Filed: 2017-10-04
- Published: 2018-06-14
- Granted: 2019-06-04
- Earliest claimed: 2016-12-08
- Assignees: Boe Technology Group Co., Ltd.; Hefei Xinsheng Optoelectronics Technology Co., Ltd.
- Applicants: Boe Technology Group Co., Ltd.; Hefei Xinsheng Optoelectronics Technology Co., Ltd.
- Inventors: Maoxiu Zhou; Haipeng Yang; Ke Dai; Yongjun Yoon; Zhou Rui
- Web page: https://patentgrep.com/patent/US10311787B2

## CPC

- G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element
- G09G 3/3225: using an active matrix
- G09G 3/3266: Details of drivers for scan electrodes
- G09G 3/3291: in which the data driver supplies a variable data voltage for setting the current through, or the voltage across, the light-emitting elements
- G09G 2300/0814: used for selection purposes, e.g. logical AND for partial update
- G09G 2300/0819: used for counteracting undesired variations, e.g. feedback or autozeroing
- G09G 2300/0842: forming a memory circuit, e.g. a dynamic memory with one capacitor
- G09G 2310/0248: Precharge or discharge of column electrodes before or after applying exact column voltages
- G09G 2310/08: Details of timing specific for flat panels, other than clock recovery
- G09G 2320/0233: Improving the luminance or brightness uniformity across the screen
- G09G 2330/021: Power management, e.g. power saving
- 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

The present disclosure provides a pixel driving circuit, a driving method, a pixel unit, and a display apparatus. The pixel driving circuit includes a driving transistor, a charging/discharging circuitry, a light-emitting control circuitry, a data write-in control circuitry, and a charging/discharging control circuitry, where a first electrode of the charging/discharging circuitry is connected to a second electrode of the driving transistor, and the charging/discharging control circuitry is configured to enable a first electrode of the driving transistor to be electrically connected to a second level output terminal under the control of a data line, and enable a second terminal of the charging/discharging circuitry to be electrically connected to a gate electrode of the driving transistor under the control of a first scan line.

## Claims

### Claim 1

A pixel driving circuit, comprising:
a driving transistor, a first electrode of which is connected to a light emitting component;
a charging/discharging circuitry, a first terminal of which is connected to a second electrode of the driving transistor;
a light-emitting control circuitry, connected to a first scan line, the second electrode of the driving transistor, and a first level output terminal, and configured to enable the second electrode of the driving transistor to be electrically connected to the first level output terminal under the control of the first scan line;
a data write-in control circuitry, connected to a data line, a second scan line, and a gate electrode of the driving transistor, and configured to enable the gate electrode of the driving transistor to be electrically connected to the data line under the control of the second scan line; and
a charging/discharging control circuitry, connected to the data line, the first electrode of the driving transistor, a second level output terminal, the first scan line, a second terminal of the charging/discharging circuitry, and the gate electrode of the driving transistor, and configured to enable the first electrode of the driving transistor to be electrically connected to the second level output terminal under the control of the data line, and enable the second terminal of the charging/discharging circuitry to be electrically connected to the gate electrode of the driving transistor under the control of the first scan line.

### Claim 2 (depends on 1)

The pixel driving circuit of claim 1, wherein a working cycle of the pixel driving circuit comprises a charging phase, a circuit adjustment phase, and a light-emitting phase, and wherein the charging/discharging control circuitry is further configured to control the first electrode of the driving transistor to be electrically connected to the second level output terminal during the circuit adjustment phase under the control of the data line, and to control the second terminal of the charging circuitry to be electrically connected to the gate electrode of the driving transistor during both the charging phase and the light-emitting phase under the control of the first scan line.

### Claim 3 (depends on 2)

The pixel driving circuit of claim 2, wherein the light-emitting control circuitry is further configured to control the second electrode of the driving transistor to be electrically connected to the first level output terminal during both the charging phase and the light-emitting phase under the control of the first scan line, and wherein the data write-in control circuitry is further to control the gate electrode of the driving transistor to be electrically connected to the data line during both the charging phase and the circuit adjustment phase under the control of the second scan line.

### Claim 4 (depends on 1)

The pixel driving circuit of claim 1, wherein the light-emitting control circuitry includes a light-emitting control transistor, a gate electrode of which is connected to the first scan line, a first electrode of which is connected to the first electrode of the driving transistor, and a second electrode of which is connected to the first level output terminal.

### Claim 5 (depends on 1)

The pixel driving circuitry of claim 1, wherein the data write-in control circuitry includes a data write-in control transistor, a gate electrode of which is connected to the second scan line, a first electrode of which is connected to the data line, and a second electrode of which is connected to the gate electrode of the driving transistor.

### Claim 6 (depends on 1)

The pixel driving circuit of claim 1, wherein the charging/discharging control circuitry includes:
a first charging/discharging control transistor, a gate electrode of which is connected to the data line, a first electrode of which is connected to the second level output terminal, and a second electrode of which is connected to the first electrode of the driving transistor; and
a second charging/discharging control transistor, a gate electrode of which is connected to the first scan line, a first electrode of which is connected to the gate electrode of the driving transistor, and a second electrode of which is connected to the second terminal of the charging/discharging circuitry.

### Claim 7 (depends on 6)

The pixel driving circuit of claim 6, wherein the charging/discharging circuitry comprises a storage capacitor, the storage capacitor, a first terminal of which is connected to the second electrode of the driving transistor and a second terminal of which is connected to the second electrode of the second charging/discharging control transistor.

### Claim 8 (depends on 7)

The pixel driving circuit of claim 7, wherein the light-emitting control circuitry comprises a light-emitting control transistor, a gate electrode of which is connected to the first scan line, a first electrode of which is connected to the first electrode of the driving transistor, and a second electrode of which is connected to the first level output terminal; and
wherein the data write-in control circuitry comprises a data write-in control transistor, a gate electrode of which is connected to the second scan line, a first electrode of which is connected to the data line, and a second electrode of which is connected to the gate electrode of the driving transistor.

### Claim 9 (depends on 8)

A driving method for the pixel driving circuit of claim 8, wherein a working cycle of the pixel driving circuit comprises a charging phase, a circuit adjustment phase, and a light-emitting phase, the driving transistor is an n-type transistor, and the driving method comprises:
during the charging phase, outputting, by the data line, a low level, outputting, by the first scan line, a high level, and outputting, by the second scan line, a high level, so as to turn on the light-emitting control transistor, the data write-in control transistor, and the second charging/discharging control transistor, and turn off the driving transistor and the first charging/discharging control transistor;
during the circuit adjustment phase, outputting, by the data line, a high level, outputting, by the first scan line, a low level, and outputting, by the second scan line, a high level, so as to turn off the light-emitting control transistor and the second charging/discharging control transistor, and turn on the data write-in control transistor, the driving transistor, and the first charging/discharging control transistor; and
during the light-emitting phase, outputting, by the data line, a low level, outputting, by the first scan line, a high level, and outputting, by the second scan line, a low level, so as to turn off the data write-in control transistor and the first charging/discharging control transistor, and so as to turn on the light-emitting control transistor, the driving transistor, and the second charging/discharging control transistor.

### Claim 10 (depends on 9)

The driving method of claim 9, wherein, during the circuit adjustment phase, a low level output from the first scan line is greater than a reverse breakdown voltage of the light-emitting control transistor, and is smaller than a voltage difference between the threshold voltage of the light-emitting control transistor and a turn-off voltage of the light-emitting control transistor, and a high level output from the second scan line is between a data voltage corresponding to a lowest brightness value and a data voltage corresponding to a highest brightness value.

### Claim 11 (depends on 1)

The pixel driving circuit of claim 1, wherein the charging/discharging circuitry comprises a storage capacitor, a first terminal of which is connected to the second electrode of the driving transistor and a second terminal of which is connected to the charging/discharging control circuitry.

### Claim 12 (depends on 1)

A driving method for the pixel driving circuit of claim 1, wherein a working cycle of the pixel driving circuit comprises a charging phase, a circuit adjustment phase, and a light-emitting phase, and the method comprises:
during the charging phase, controlling, by the light-emitting control circuitry, the first electrode of the driving transistor to be electrically connected to the first level output terminal under the control of the first scan line, controlling, by the data write-in control circuitry, the gate electrode of the driving transistor to be electrically connected to the data line under the control of the second scan line, outputting, by the data line, a third level so as to turn off the driving transistor, and controlling, by the charging/discharging control circuitry, the second terminal of the charging/discharging circuitry be electrically connected to the gate electrode of the driving transistor under the control of the first scan line;
during the circuit adjustment phase, outputting, by the data line, a data voltage, controlling, by the data write-in control circuitry, the gate electrode of the driving transistor to be electrically connected to the data line under the control of the second scan line, and controlling, by the charging/discharging control circuitry, the first electrode of the driving transistor to be electrically connected to the second level output terminal under the control of the data voltage, so as to turn on the driving transistor until the charging/discharging circuitry discharges, such that a potential difference between a voltage at the first terminal of the charging/discharging circuitry and a voltage at the second terminal of the charging/discharging circuitry is a sum of the data voltage and a threshold voltage of the driving transistor; and
during the light-emitting phase, controlling, by the light-emitting control circuitry, the first electrode of the driving transistor to be electrically connected to the first level output terminal, and controlling, by the charging/discharging control circuitry, the second terminal of the charging/discharging circuitry to be electrically connected to the gate electrode of the driving transistor under the control of the first scan line, so as to maintain a gate voltage of the driving transistor at the sum of the data voltage and the threshold voltage of the driving transistor, such that the driving transistor is turned on to compensate for the threshold voltage of the driving transistor by controlling the gate voltage of the driving transistor.

### Claim 13 (depends on 12)

The driving method of claim 12, wherein the third level is determined according to the first level and the threshold voltage of the driving transistor.

### Claim 14 (depends on 12)

The driving method of claim 12, wherein, in the case that the driving transistor is an n-type transistor, a difference between the third level and the first level is smaller than the threshold voltage of the driving transistor so as to turn off the driving transistor during the charging phase.

### Claim 15 (depends on 12)

The driving method of claim 12, wherein, in the case that the driving transistor is a p-type transistor, a difference between the third level and the first level is greater than the threshold voltage of the driving transistor so as to turn off the driving transistor during the charging phase.

### Claim 16 (depends on 1)

A pixel unit, comprising a light emitting component and a pixel driving circuit of claim 1, wherein the pixel driving circuit is connected to the light emitting component and configured to drive the light emitting component to emit light.

### Claim 17 (depends on 16)

A display apparatus, comprising a pixel unit of claim 16.