Pixel circuit and driving method thereof, display panel

Patent metadata

Field	Value
Publication number	US-11373582-B2
Application number	US-201916492676-A
Country	US
Kind code	B2
Filing date	Feb 15, 2019
Priority date	Jun 8, 2018
Publication date	Jun 28, 2022
Grant date	Jun 28, 2022

Abstract

A pixel circuit, a method of driving a pixel circuit and a display panel. The pixel circuit includes: a drive circuit, a data writing circuit, a compensation circuit, and a light emitting element. The drive circuit includes a control terminal, a first terminal and a second terminal, and is configured to control a drive current flowing through the first terminal and the second terminal for driving the light emitting element to emit light. The data writing circuit is configured to write a data signal to a first terminal of the drive circuit in response to a first scanning signal. The compensation circuit stores a data signal written by the data writing circuit and compensates the drive circuit in response to a second scanning signal. A first terminal of the light emitting element receives a drive current, and a second terminal thereof is connected to a second voltage terminal.

First claim

What is claimed is:

1. A pixel circuit, comprising: a drive circuit, a data writing circuit, a compensation circuit, and a light emitting element, wherein
the drive circuit includes a control terminal, a first terminal and a second terminal, and is configured to control a drive current flowing through the first terminal and the second terminal for driving the light emitting element to emit light;
the data writing circuit is connected to a first terminal of the drive circuit and configured to write a data signal to the first terminal of the drive circuit in response to a first scanning signal;
the compensation circuit is connected to a control terminal and a second terminal of the drive circuit and connected to a first voltage terminal, and is configured to store a data signal written by the data writing circuit and compensate the drive circuit in response to a second scanning signal; and
the light emitting element includes a first terminal and a second terminal, and a first terminal of the light emitting element is configured to receive the drive current, and a second terminal of the light emitting element is connected to a second voltage terminal;
a first light emitting control circuit connected to the first terminal of the drive circuit and the first voltage terminal; and
a second light emitting control circuit connected to the second terminal of the drive circuit and the first terminal of the light emitting element.

2. The pixel circuit according to claim 1 ,
wherein the first light emitting control circuit is configured to apply a first voltage received from the first voltage terminal to the first terminal of the drive circuit in response to a first light emitting control signal.

3. The pixel circuit according to claim 2 , wherein the first light emitting control circuit comprises a fourth transistor; and
wherein a gate electrode of the fourth transistor is connected to a first light emitting control line for receiving the first light emitting control signal, a first electrode of the fourth transistor is connected to the first voltage terminal for receiving the first voltage, and a second electrode of the fourth transistor is connected to the first terminal of the drive circuit.

4. A method for driving the pixel circuit according to claim 2 , comprising: a data writing and compensation stage and a light emitting stage, wherein
in the data writing and compensation stage, the first scanning signal, the second scanning signal and the data signal are input to turn on the data writing circuit, the drive circuit and the compensation circuit, and the data writing circuit writes the data signal into the drive circuit, the compensation circuit stores the data signal, and the compensation circuit compensates the drive circuit; and
in the light emitting stage, the first light emitting control signal is input so as to turn on the first light emitting control circuit and the drive circuit, and the first light emitting control circuit applies the drive current to the light emitting element so that the light emitting element emits light; and
wherein the first scanning signal and the second scanning signal are simultaneously on-signals within at least part of the data writing and compensation stage and the light emitting stage.

5. The pixel circuit according to claim 2 ,
wherein the second light emitting control circuit is configured to apply the drive current to the light emitting element in response to a second light emitting control signal.

6. The pixel circuit according to claim 5 , wherein the second light emitting control circuit comprises a fifth transistor; and
wherein a gate electrode of the fifth transistor is connected to a second light emitting control line for receiving the second light emitting control signal, a first electrode of the fifth transistor is connected to the second terminal of the drive circuit, and a second electrode of the fifth transistor is connected to the first terminal of the light emitting element.

7. The pixel circuit according to claim 5 , further comprising a reset circuit,
wherein the reset circuit is connected to a reset voltage terminal and the first terminal of the light emitting element, and is configured to apply a reset voltage received from the reset voltage terminal to the first terminal of the light emitting element in response to a reset signal; and
wherein the reset signal is the second scanning signal.

8. The pixel circuit of claim 7 , wherein the compensation circuit and the reset circuit each comprise an N-type transistor, and the drive circuit, the data writing circuit, the first light emitting control circuit, and the second light emitting control circuit each comprise a P-type transistor.

9. A method for driving the pixel circuit according to claim 7 , comprising: an initialization stage, a data writing and compensation stage, a pre-light emitting stage and a light emitting stage;
wherein, in the initialization stage, the reset signal, the second scanning signal and the second light emitting control signal are input so as to turn on the reset circuit, the compensation circuit and the second light emitting control circuit, and the reset voltage is applied to the control terminal, the first terminal and the second terminal of the drive circuit and the first terminal of the light emitting element;
in the data writing and compensation stage, the first scanning signal, the second scanning signal and the data signal are input so as to turn on the data writing circuit, the drive circuit and the compensation circuit, and the data writing circuit writes the data signal into the drive circuit, the compensation circuit stores the data signal, and the compensation circuit compensates the drive circuit;
in the pre-light emitting stage, the first light emitting control signal is input so as to turn on the first light emitting control circuit and the drive circuit, and the first light emitting control circuit applies the first voltage to the first terminal of the drive circuit;
in the light emitting stage, the first light emitting control signal and the second light emitting control signal are input so as to turn on the first light emitting control circuit, the second light emitting control circuit and the drive circuit, and the second light emitting control circuit applies the drive current to the light emitting element so that the light emitting element emits light;
wherein the first scanning signal and the second scanning signal are simultaneously on signals within at least part of the initialization stage, the data writing and compensation stage, the pre-light emitting stage and the light emitting stage, and the first light emitting control signal and the second light emitting control signal are simultaneously on signals within at least part of the initialization stage, the data writing and compensation stage, the pre-light emitting stage and the light emitting stage.

10. The driving method of the pixel circuit according to claim 9 , further comprising: a data write holding stage,
wherein, in the data write holding stage, the first scanning signal is input so as to turn on the data writing circuit, and the second scanning signal is input so as to turn off the compensation circuit for holding a voltage at the control terminal of the drive circuit.

11. The pixel circuit of claim 7 , wherein the reset circuit comprises a sixth transistor; and
wherein a gate electrode of the sixth transistor is connected to a second scanning line for receiving the second scanning signal as the reset signal, a first electrode of the sixth transistor is connected to the reset voltage terminal for receiving the reset voltage, and a second electrode of the sixth transis

Assignees

• Chengdu Boe Optoelect Tech Co
• Boe Technology Group Co Ltd

Inventors

• Lee Sang Won
• Zhu Yidan

Classifications

• G09G3/3233 Primary

  with pixel circuitry controlling the current through the light-emitting element · CPC title

• G09G2310/0294

  Details of sampling or holding circuits arranged for use in a driver for data electrodes · CPC title

• G09G2310/0251

  Precharge or discharge of pixel before applying new pixel voltage · CPC title

• G09G2300/0426

  Layout of electrodes and connections · CPC title

• G09G2300/0861

  with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes · CPC title