Dual-Gate TFT Pixel Circuit Charge Sharing

Solution Overview

Problem

In TFT-LCD display panels, single-gate transistors lead to insufficient pixel electrode charging, resulting in increased power consumption and potential output voltage range exceedance, which can cause display issues like splash screen and afterimage.

Innovation Solution

The use of a dual-gate thin film transistor with a shared capacitor and transistor configuration, allowing for charge sharing before pixel unit charging, reduces power consumption and enhances driving stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If single-gate transistors are used for pixel electrode charging, then device complexity is reduced, but charging rate is insufficient and power consumption increases

Engineering Contradiction:

Improvetransistor structureVSAvoidcharging rate

Core Design Contradiction:

Device complexityVSProductivity

Solution Approach 1:

The transistor gate is segmented into two independent gates (first gate and second gate), allowing separate control of charge injection and charge sharing processes. This segmentation enables the dual-gate transistor to achieve higher charging rates by independently optimizing each function, resolving the contradiction between device simplicity and charging performance.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The shared capacitor performs preliminary charge sharing before the pixel electrode charging process. By pre-charging the pixel electrode through the shared capacitor using charges from adjacent pixel electrodes, the system reduces the charging burden on the switch transistor, thereby improving overall charging rate without significantly increasing device complexity.

Inventive Principle:

Principle #10Preliminary action

2Device complexity

If single-gate transistors are used, then device complexity is reduced, but power consumption increases due to insufficient charging

Engineering Contradiction:

Improvetransistor structureVSAvoidpower consumption

Core Design Contradiction:

Device complexityVSUse of energy by moving object

Solution Approach 1:

The shared capacitor performs preliminary charge sharing before the pixel electrode charging process. By pre-charging the pixel electrode through the shared capacitor using charges from adjacent pixel electrodes, the system reduces the charging burden on the switch transistor, thereby improving overall charging rate without significantly increasing device complexity.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Adjacent pixel electrodes serve each other by sharing charges through the shared capacitor. This self-service mechanism allows the display panel to reduce overall power consumption by utilizing the electrical charges already present in the system rather than requiring complete re-charging from the data lines for each pixel.

Inventive Principle:

Principle #25Self-service

3Device complexity

If single-gate transistors are used, then device complexity is reduced, but display stability deteriorates due to voltage fluctuations

Engineering Contradiction:

Improvetransistor structureVSAvoiddisplay stability

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The shared capacitor acts as an intermediary between adjacent pixel electrodes and the current pixel electrode being charged. This intermediary component stabilizes voltage fluctuations by providing a buffer that smooths out charge transfer variations, thereby improving display stability without requiring complex transistor structures.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The shared capacitor performs preliminary charge sharing before the pixel electrode charging process. By pre-charging the pixel electrode through the shared capacitor using charges from adjacent pixel electrodes, the system reduces the charging burden on the switch transistor, thereby improving overall charging rate without significantly increasing device complexity.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS10585320B2Array substrate and driving method and manufacturing method thereof

Publication Date: 2020.03.10 BOE TECHNOLOGY GROUP CO LTD

AI summary

The embodiment of the present disclosure discloses an array substrate. The array substrate comprises: a base, a plurality of first scanning lines, a plurality of second scanning lines, a plurality of data lines, a common electrode line, and a plurality of pixel units. Each of the pixel units comprises: a first electrode, a second electrode, a switch transistor, a shared transistor and a shared capacitor. The switch transistor has a first terminal coupled to the second electrode, a second terminal coupled to one of the plurality of data lines, a bottom gate coupled to one of the plurality of first scanning lines, and a top gate coupled to one of the plurality of second scanning lines, and is configured to transfer a data signal of the data line to the second electrode under the control of a first scanning signal and a second scanning signal.