# US 10,769,998 B2 · Pixel circuit and driving method thereof, array substrate, and display panel

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- Number: US 10,769,998 B2
- Document ID: US10769998B2
- Status: Granted
- Kind: B2
- Application number: 16/225,633
- Filed: 2018-12-19
- Published: 2019-11-28
- Granted: 2020-09-08
- Earliest claimed: 2018-05-28
- 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: Yingsong Xu
- Web page: https://patentgrep.com/patent/US10769998B2

## CPC

- G09G 3/3241: the current through the light-emitting element being set using a data current provided by the data driver, e.g. by using a two-transistor current mirror
- G09G 3/32: semiconductive, e.g. using light-emitting diodes [LED]
- G09G 3/3233: with pixel circuitry controlling the current through the light-emitting element
- G09G 3/3225: using an active matrix
- G09G 2300/0819: used for counteracting undesired variations, e.g. feedback or autozeroing
- G09G 2300/0852: being a dynamic memory with more than one capacitor
- G09G 2300/0861: with additional control of the display period without amending the charge stored in a pixel memory, e.g. by means of additional select electrodes
- G09G 2320/0204: Compensation of DC component across the pixels in flat panels
- G09G 2320/0223: Compensation for problems related to R-C delay and attenuation in electrodes of matrix panels, e.g. in gate electrodes or on-substrate video signal electrodes
- G09G 2320/0233: Improving the luminance or brightness uniformity across the screen
- G09G 2320/045: Compensation of drifts in the characteristics of light emitting or modulating elements
- 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 disclosure provide a pixel circuit and a drive method thereof, an array substrate, and a display panel. The pixel circuit includes a drive transistor, a data write circuit, a light emission control circuit, a compensation circuit, a reset circuit, and a light emitting device. A first control electrode of the drive transistor is coupled to a first node, a second control electrode of the drive transistor is coupled to a second node, a first electrode of the drive transistor is coupled to a first voltage signal terminal, and a second electrode of the drive transistor is coupled to a third node and may provide a drive current. The light emitting device is coupled between the light emission control circuit and a second voltage signal terminal and may emit light based on the drive current.

## Claims

### Claim 1

A method for driving a pixel circuit,
wherein the pixel circuit comprises a drive transistor, a data write circuit, a light emission control circuit, a compensation circuit, a reset circuit, and a light emitting device,
wherein a first control electrode of the drive transistor is coupled to a first node, wherein a second control electrode of the drive transistor is coupled to a second node, wherein a first electrode of the drive transistor is coupled to a first voltage signal terminal, wherein a second electrode of the drive transistor is coupled to a third node, and wherein the drive transistor is configured to provide a drive current;
wherein the data write circuit is configured to provide a reference signal or a data signal from a data line to the first node according to a first drive signal from a first drive signal terminal;
wherein the light emission control circuit is configured to control, according to a pixel drive signal from a pixel drive signal terminal, to provide the drive current to the light emitting device;
wherein the compensation circuit is configured to control a voltage of the second node to be equal to a voltage of the third node according to a second drive signal from a second drive signal terminal;
wherein the reset circuit is configured to provide a third voltage signal from a third voltage signal terminal to the second node according to a reset signal from a reset signal terminal; and
wherein the light emitting device is coupled between the light emission control circuit and a second voltage signal terminal and is configured to emit light according to the drive current;
wherein the method comprises:
providing the reset signal, the second drive signal, and the pixel drive signal, such that the voltage of the second node is equal to the voltage of the third node, and the drive current of the drive transistor is provided to the third voltage signal terminal via the compensation circuit and the reset circuit to reset the light emitting device;
providing the second drive signal, such that the voltage of the second node and the voltage of the third node rise to the equal voltage, and providing the first drive signal to provide the reference signal to the first node, such that the threshold voltage of the drive transistor is a voltage difference between a voltage of the reference signal and a voltage of a first voltage signal from the first voltage signal terminal;
providing the first drive signal to provide the data signal to the first node, and holding the threshold voltage of the drive transistor to be the voltage difference between the voltage of the reference signal and the voltage of the first voltage signal; and
providing the pixel drive signal, such that the light emitting device emits light according to the drive current of the drive transistor.

### Claim 2 (depends on 1)

The method according to claim 1,
wherein the first drive signal is a gate drive signal for the pixel circuit; and
wherein the second drive signal is a gate drive signal for another pixel circuit.

### Claim 3 (depends on 1)

The method according to claim 1,
wherein a voltage of the data signal is smaller than a voltage of the reference signal, and wherein the voltage of the reference signal is smaller than a voltage of the first voltage signal from the first voltage signal terminal.

### Claim 4

An array substrate comprising:
a plurality of pixel circuits, the plurality of pixel circuits arranged in a matrix;
wherein each of the pixel circuits comprises a drive transistor, a data write circuit, a light emission control circuit, a compensation circuit, a reset circuit, and a light emitting device,
wherein a first control electrode of the drive transistor is coupled to a first node, wherein a second control electrode of the drive transistor is coupled to a second node, wherein a first electrode of the drive transistor is coupled to a first voltage signal terminal, wherein a second electrode of the drive transistor is coupled to a third node, and wherein the drive transistor is configured to provide a drive current;
wherein the data write circuit is configured to provide a reference signal or a data signal from a data line to the first node according to a first drive signal from a first drive signal terminal;
wherein the light emission control circuit is configured to control, according to a pixel drive signal from a pixel drive signal terminal, to provide the drive current to the light emitting device;
wherein the compensation circuit is configured to control a voltage of the second node to be equal to a voltage of the third node according to a second drive signal from a second drive signal terminal;
wherein the reset circuit is configured to provide a third voltage signal from a third voltage signal terminal to the second node according to a reset signal from a reset signal terminal; and
wherein the light emitting device is coupled between the light emission control circuit and a second voltage signal terminal and is configured to emit light according to the drive current
wherein the array substrate further comprises a plurality of cascade-coupled gate driving transistors, wherein a gate drive signal provided by the (n−1)th stage gate driving transistor serves as a second drive signal of the nth row of pixel circuits, and wherein a gate drive signal provided by the nth stage gate driving transistor serves as a first drive signal of the nth row of pixel circuits.

### Claim 5 (depends on 4)

The array substrate according to claim 4, wherein the pixel circuit further comprises:
a voltage holding circuit, configured to hold at least one of a voltage difference between a first voltage signal terminal and a first node, and a voltage difference between a first voltage signal terminal and a second node.

### Claim 6 (depends on 5)

The array substrate according to claim 5, wherein the voltage holding circuit comprises at least one of:
a first capacitor coupled between the first voltage signal terminal and the first node; and
a second capacitor coupled between the first voltage signal terminal and the second node.

### Claim 7 (depends on 4)

The array substrate according to claim 4,
wherein a voltage of the data signal is smaller than a voltage of the reference signal, and wherein the voltage of the reference signal is smaller than a voltage of a first voltage signal from the first voltage signal terminal.

### Claim 8 (depends on 4)

A display panel comprising the array substrate according to claim 4.

### Claim 9 (depends on 8)

The display panel according to claim 8, wherein the pixel circuit further comprises:
a voltage holding circuit, configured to hold at least one of a voltage difference between a first voltage signal terminal and a first node, and a voltage difference between a first voltage signal terminal and a second node.