Pixel circuit and driving method thereof, display panel and display apparatus

Patent metadata

Field	Value
Publication number	US-11869423-B2
Application number	US-201916486201-A
Country	US
Kind code	B2
Filing date	Jan 14, 2019
Priority date	Jun 13, 2018
Publication date	Jan 9, 2024
Grant date	Jan 9, 2024

Abstract

A pixel circuit, a display panel, a display apparatus and a driving method. The pixel circuit includes a data signal writing module, a driving module, a threshold compensation transistor, a first power voltage writing module and a light-emitting module, wherein the driving module includes a driving transistor.

First claim

What is claimed is:

1. A pixel circuit, comprising: a data signal writing module; a driving module; a threshold compensation transistor; a first power voltage writing module; a reference signal writing module; and a light-emitting module, wherein the driving module comprises a driving transistor, wherein:
the first power voltage writing module is connected to a first light-emitting control signal terminal, a first power voltage terminal, a source of the driving transistor and a gate of the driving transistor, and the first power voltage writing module is configured to write a first power voltage signal of the first power voltage terminal to the source of the driving transistor under control of a first light-emitting control signal of the first light-emitting control signal terminal;
the data signal writing module is connected to a writing control terminal, a data signal terminal and the source of the driving transistor, and the data signal writing module is configured to transmit a data signal of the data signal terminal to the source of the driving transistor under control of a writing control signal of the writing control terminal;
the threshold compensation transistor has a gate connected to a first node, a source connected to the gate of the driving transistor and a drain connected to a drain of the driving transistor, and the threshold compensation transistor is configured to perform voltage compensation to the gate of the driving transistor in case that the first node is at an valid level;
the reference signal writing module is connected to a reference control terminal, a reference signal terminal, the first light-emitting control signal terminal and the first node, and the reference signal writing module is configured to control potential of the first node according to a reference control signal of the reference control terminal and the first light-emitting control signal of the first light-emitting control signal terminal; and
the light-emitting module has a first terminal connected to the drain of the driving transistor and a second terminal connected to a second power voltage terminal.

2. The pixel circuit of claim 1 , wherein the threshold compensation transistor is an oxide transistor.

3. The pixel circuit of claim 1 , wherein the pixel circuit further comprises:
a reset module connected to a reset control terminal, a reset potential terminal and the first terminal of the light-emitting module and configured to reset the first terminal of the light-emitting module and the gate of the driving transistor under control of a reset control signal of the reset control terminal.

4. The pixel circuit of claim 3 , wherein the reset module comprises: a reset transistor having a gate connected to the reset control terminal, a source connected to the first terminal of the light-emitting module, and a drain connected to the reset potential terminal.

5. The pixel circuit according to claim 4 , wherein a second power voltage of the second power voltage terminal is lower than a reset potential of the reset potential terminal.

6. The pixel circuit of claim 1 , wherein the pixel circuit further comprises:
a light-emitting control module connected to a second light-emitting control signal terminal, the drain of the drive transistor and the first terminal of the light-emitting module, and configured to drive the light-emitting module to emit light under control of a second light-emitting control signal of the second light-emitting control signal terminal.

7. The pixel circuit of claim 6 , wherein the light-emitting control module comprises:
a light-emitting control transistor having a gate connected to the second light-emitting control signal terminal, a source connected to the drain of the driving transistor, and a drain connected to the first terminal of the light-emitting module.

8. The pixel circuit of claim 1 , wherein the reference signal writing module comprises:
a reference signal writing transistor having a gate connected to the reference control terminal, a source connected to the first node, and a drain connected to the reference signal terminal; and
a first capacitor connected between the first light-emitting control signal terminal and the first node.

9. The pixel circuit of claim 1 , wherein the data signal writing module comprises:
a data writing transistor having a gate connected to a data writing control terminal, a source connected to the data signal terminal, and a drain connected to the source of the drive transistor.

10. The pixel circuit of claim 1 , wherein the first power voltage writing module comprises:
a first power voltage writing transistor having a gate connected to the first light-emitting control signal terminal, a source connected to the first power voltage terminal, and a drain connected to the source of the driving transistor.

11. The pixel circuit of claim 1 , wherein the driving module further comprises:
a second capacitor connected between the first power voltage terminal and the gate of the driving transistor.

12. The pixel circuit of claim 1 , wherein the light-emitting module comprises:
an organic light-emitting diode (OLED), an anode of the OLED serving as the first terminal of the light-emitting module, and a cathode of the OLED serving as the second terminal of the light-emitting module.

13. A display panel comprising the pixel circuit of claim 1 .

14. A method for driving the pixel circuit of claim 1 , comprising:
in a data writing and threshold compensation phase, writing the data signal of the data signal terminal to the source of the driving transistor, the writing control signal of the writing control terminal being at a first level, and the reference control signal of the reference control terminal being hopped from the first level to a second level, level of the first light-emitting control signal being hopped from the first level to the second level, level of the first node being raised, and potential of the gate of the driving transistor being compensated under control of the first node; and
in a light-emitting phase, directing a driving current of the driving transistor to the light-emitting module to drive the light-emitting module to emit light, wherein the second light-emitting control signal of the second light-emitting control signal terminal is at the first level.

15. The method of claim 14 , wherein: the pixel circuit further comprises:
a reference signal writing module connected to the reference control terminal, the reference signal terminal, the first light-emitting control signal terminal, and the first node; and
the method further comprises: a first initialization phase and a second initialization phase,
in the first initialization phase, in which the reference control signal of the reference control terminal is at a first level, transmitting the reference signal of the reference signal terminal to the first node; and
in the second initialization phase, transitioning the reference control signal of the reference control terminal from the first level to the second level, transitioning the level of the first light-emitting control signal from the first level to the second level, and raising the level of the first node.

16. The method of claim 15 , wherein the reference signal of the reference signal terminal is adjusted based on an offset of a threshold voltage of the threshold compensation transistor after the pixel circuit has operated for a preset time.

17. The method of claim 14 , wherein: the pixel circuit further comprises:
a reset module connected to the reset control terminal, the reset pote

Assignees

• Boe Technology Group Co Ltd

Inventors

• Gao Xueling
• Yang Chengchung
• Wang Tieshi
• Peng Jintao

Classifications

• G09G3/3233 Primary

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

• G09G2300/0426

  Layout of electrodes and connections · CPC title

• G09G2300/0819

  used for counteracting undesired variations, e.g. feedback or autozeroing · CPC title

• G09G2300/0852

  being a dynamic memory with more than one capacitor · CPC title

• G09G2310/08

  Details of timing specific for flat panels, other than clock recovery · CPC title