Pixel circuit

Patent metadata

Field	Value
Publication number	US-11495155-B2
Application number	US-202016952199-A
Country	US
Kind code	B2
Filing date	Nov 19, 2020
Priority date	Jun 14, 2018
Publication date	Nov 8, 2022
Grant date	Nov 8, 2022

Abstract

A pixel circuit includes a light emitting element, a first driver transistor, a second driver transistor, and a first compensation capacitor. A first terminal of the first driving transistor is configured to receive a power signal, and a second terminal of the first driving transistor is electrically coupled to the light emitting element. A first terminal of the second driving transistor receives the power signal, and a control terminal of the second driving transistor is electrically coupled to the light emitting element. The first compensation capacitance is electrically coupled to a control terminal of the first driving transistor and the second terminal of the second driving transistor, respectively.

First claim

What is claimed is:

1. A pixel circuit, comprising:
a light emitting element;
a first driver transistor comprising a first terminal, a second terminal and a control terminal, wherein the first terminal of the first driving transistor is configured to receive a power signal, and the second terminal of the first driving transistor is electrically connected to the light emitting element;
a second driver transistor comprising a first terminal, a second terminal and a control terminal, wherein the first terminal of the second driving transistor receives the power signal, and the control terminal of the second driving transistor is electrically connected to the light emitting element;
a first compensation capacitor electrically connected to the control terminal of the first driving transistor and the second terminal of the second driving transistor; and
a second compensation capacitor comprising a first terminal and a second terminal, wherein the first terminal of the second compensation capacitor is electrically connected to a reference voltage source, and the second terminal of the second compensation capacitor is electrically connected to the control terminal of the first driver transistor;
wherein a threshold voltage value of the first driver transistor matches to a threshold voltage value of the second driver transistor;
wherein the second terminal of the second driver transistor is electrically connected to the first compensation capacitor through a compensation node.

2. The pixel circuit of claim 1 , wherein the threshold voltage value of the first driving transistor and the threshold voltage value of the second driving transistor have a first matching relationship, a capacitance value of the first compensation capacitor and a capacitance value of the second compensation capacitor have a second matching relationship, and the first matching relationship is the same as the second matching relationship.

3. The pixel circuit of claim 2 , wherein the first driving transistor and the second driving transistor have the same threshold voltage value, and the first compensation capacitor and the second compensation capacitor have the same capacitance value.

4. The pixel circuit of claim 1 , further comprising:
a transistor switch comprising a first terminal, a second terminal and a control terminal, wherein the first terminal of the transistor switch is configured to receive a data signal, the second terminal of the transistor switch is electrically connected to the control terminal of the first driving transistor, and the control terminal of the transistor switch is configured to receive a gate signal.

Assignees

• Au Optronics Corp

Inventors

• Lin Chih-Lung
• Tseng Chin-Hsien
• Lai Po-Cheng
• Lin Yu-Sheng
• Cheng Mao-Hsun

Classifications

• G09G2300/0465

  Improved aperture ratio, e.g. by size reduction of the pixel circuit, e.g. for improving the pixel density or the maximum displayable luminance or brightness · CPC title

• G09G2300/0852

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

• G09G2300/043

  Compensation electrodes or other additional electrodes in matrix displays related to distortions or compensation signals, e.g. for modifying TFT threshold voltage in column driver · CPC title

• G09G2300/0819

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

• G09G3/20 Primary

  for presentation of an assembly of a number of characters, e.g. a page, by composing the assembly by combination of individual elements arranged in a matrix {no fixed position being assigned to or needed to be assigned to the individual characters or partial characters} · CPC title