Method for driving a pixel circuit

Patent metadata

Field	Value
Publication number	US-11854459-B2
Application number	US-202217988091-A
Country	US
Kind code	B2
Filing date	Nov 16, 2022
Priority date	Sep 1, 2020
Publication date	Dec 26, 2023
Grant date	Dec 26, 2023

Abstract

A method for driving a pixel circuit. The pixel circuit includes a drive transistor. The method includes: acquiring a theoretical threshold voltage of the drive transistor and actual threshold voltages of the drive transistor at a plurality of different gray levels; determining compensation data voltages of the drive transistor at the plurality of different gray levels according to the theoretical threshold voltage of the drive transistor and the actual threshold voltages of the drive transistor at the plurality of different gray levels; and driving the pixel circuit emit light according to the compensation data voltages of the drive transistor at the plurality of different gray levels.

First claim

What is claimed is:

1. A method for driving a pixel circuit, wherein the pixel circuit comprises a drive transistor, and the method comprises:
acquiring a theoretical threshold voltage of the drive transistor and actual threshold voltages of the drive transistor at a plurality of different gray levels;
determining compensation data voltages of the drive transistor at the plurality of different gray levels according to the theoretical threshold voltage of the drive transistor and the actual threshold voltages of the drive transistor at the plurality of different gray levels;
driving the pixel circuit to emit light according to the compensation data voltages of the drive transistor at the plurality of different gray levels,
providing a preset voltage, writing the preset voltage to a gate of the drive transistor through threshold compensation until a gate potential of the drive transistor remains unchanged, reading a current gate potential of the drive transistor and determining the theoretical threshold voltage of the drive transistor according to the preset voltage and the current gate potential of the drive transistor; and
providing a plurality of different gray level voltages corresponding to the plurality of different gray levels sequentially, writing the plurality of different gray level voltages to the gate of the drive transistor through the threshold compensation, reading a plurality of gate potentials of the drive transistor in one-to-one correspondence with the plurality of different gray level voltages and determining the actual threshold voltages of the drive transistor at the plurality of different gray levels according to the plurality of different gray level voltages and the plurality of gate potentials of the drive transistor in one-to-one correspondence with the plurality of different gray level voltages.

2. The method according to claim 1 , wherein the pixel circuit further comprises a data voltage write transistor, a threshold compensation transistor, a first light emission control transistor, a second light emission control transistor, a first initialization transistor, a second initialization transistor, a capacitor and a light emission device, wherein a first electrode of the data voltage write transistor is electrically connected to a data signal line, and a second electrode of the data voltage write transistor is electrically connected to a first electrode of the drive transistor and a second electrode of the first light emission control transistor; a first electrode of the first light emission control transistor and a first terminal of the capacitor are electrically connected to a power signal line; a second electrode of the drive transistor is electrically connected to a second electrode of the threshold compensation transistor and a first electrode of the second light emission control transistor; a first electrode of the threshold compensation transistor and the gate of the drive transistor are electrically connected to a second terminal of the capacitor and a first electrode of the first initialization transistor; a second electrode of the first initialization transistor and a first electrode of the second initialization transistor are electrically connected to a reference signal line; a second electrode of the second light emission control transistor and a second electrode of the second initialization transistor are electrically connected to the light emission device; a gate of the first light emission control transistor and a gate of the second light emission control transistor are electrically connected to a light emission control signal line; a gate of the data voltage write transistor and a gate of the threshold compensation transistor are electrically connected to a second scan signal line; and a gate of the first initialization transistor is electrically connected to a first scan signal line; and
wherein providing the preset voltage, writing the preset voltage to the gate of the drive transistor through the threshold compensation until the gate potential of the drive transistor remains unchanged, reading the current gate potential of the drive transistor and determining the theoretical threshold voltage of the drive transistor according to the preset voltage and the current gate potential of the drive transistor comprise:
in a first compensation stage, controlling the data voltage write transistor and the threshold compensation transistor to turn on, providing the preset voltage through the data signal line and writing the preset voltage to the gate of the drive transistor through the threshold compensation until the gate potential of the drive transistor remains unchanged;
in a first data read stage, controlling the first initialization transistor to turn on and reading the current gate potential of the drive transistor through the reference signal line and the first initialization transistor; and
computing a difference value between the preset voltage and the current gate potential of the drive transistor to determine the theoretical threshold voltage of the drive transistor.

3. The method according to claim 2 , before the first compensation stage, the method further comprising:
in a first initialization stage, controlling the first initialization transistor to turn on and providing a reference signal to the gate of the drive transistor through the reference signal line.

4. The method according to claim 2 , wherein providing the plurality of different gray level voltages corresponding to the plurality of different gray levels sequentially, writing the plurality of different gray level voltages to the gate of the drive transistor through the threshold compensation, reading the plurality of gate potentials of the drive transistor in one-to-one correspondence with the plurality of different gray level voltages and determining the actual threshold voltages of the drive transistor at the plurality of different gray levels according to the plurality of different gray level voltages and the plurality of gate potentials of the drive transistor in one-to-one correspondence with the plurality of different gray level voltages comprise:
providing one gray level voltage of the plurality of different gray level voltages, writing the one gray level voltage to the gate of the drive transistor through the threshold compensation, reading the current gate potential of the drive transistor and determining an actual threshold voltage of the drive transistor at a gray level corresponding to the one gray level voltage according to the one gray level voltage and the current gate potential of the drive transistor; and
repeatedly performing the step of determining the actual threshold voltage of the drive transistor at the gray level corresponding to the one gray level voltage and sequentially providing a plurality of gray level voltages to acquire actual threshold voltages of the drive transistor at a plurality of gray levels.

5. The method according to claim 4 , wherein providing the one gray level voltage of the plurality of different gray level voltages, writing the one gray level voltage to the gate of the drive transistor through the threshold compensation, reading the current gate potential of the drive transistor and determining the actual threshold voltage of the drive transistor at the gray level corresponding to the one gray level voltage according to the one gray level voltage and the current gate potential of the drive transistor comprise:
in a second initialization stage, controlling the first initialization transistor to turn on to reset a gate potential of the drive transistor;
in a second compensation stage, controlling the data voltage write transistor and the threshold compensation transistor to turn on and providing the one gray level voltage to the gate of the drive transistor through the dat

Assignees

• Yungu Guan Tech Co Ltd

Inventors

• Wang Ling
• Gai Cuili
• Mi Lei

Classifications

• G09G3/2092 Primary

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