GOA Circuit Transistor Drift Mitigation via Bidirectional Stress

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Solution Overview

Problem

Gate On Array (GOA) circuits experience deteriorated transistor characteristics due to continuous directional driving stress, leading to threshold voltage drift and adverse effects on charging/discharging capability, resulting in output abnormalities.

Innovation Solution

A gate driving unit comprising a first pull-down node control circuit, a second pull-down node control circuit, and a pull-up node resetting circuit, which control the electrical connection and disconnection of nodes under the influence of potential voltages to apply reverse stress and prevent threshold voltage drift.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If GOA circuit operates continuously in same direction, then display function is maintained, but transistor threshold voltage drifts and charging/discharging capability deteriorates

Engineering Contradiction:

Improvetransistor characteristic stabilityVSAvoidcontinuous operation time

Core Design Contradiction:

ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent implements periodic bidirectional stress application by alternating the stress application circuit connection between first and second control voltage ends at regular intervals. This periodic reversal prevents cumulative threshold voltage drift by applying stress in both directions, thereby maintaining transistor characteristic stability during continuous operation.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent applies stress in reverse direction by switching the connection of the stress application circuit between the first control voltage end and the second control voltage end. This inversion of stress direction compensates for threshold voltage drift by applying opposite polarity stress, preventing characteristic deterioration.

Inventive Principle:

Principle #13The other way round (Inversion)

2Reliability

If stress application circuit is switched between control voltage ends, then threshold voltage drift is prevented, but circuit complexity increases

Engineering Contradiction:

Improvetransistor characteristic stabilityVSAvoidgate driving unit structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The stress application circuit serves multiple functions: it applies stress in both directions, acts as a control switch, and integrates with existing gate driving circuitry. By making this single circuit multi-functional, the patent avoids adding separate dedicated components for each function, thereby limiting the increase in overall circuit complexity.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the stress application function with the existing control voltage ends and switching circuitry of the GOA driver. Instead of adding a completely separate stress application system, the functionality is integrated into the existing circuit architecture, reducing the net increase in device complexity.

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS10854130B2Gate driving unit, gate driving method, gate driving circuit and display device

Publication Date: 2020.12.01 HEFEI XINSHENG OPTOELECTRONICS TECH CO LTD

AI summary

A gate driving unit includes a first pull-down node control circuit, a second pull-down node control circuit and a pull-up node resetting circuit. The first/second pull-down node control circuit is configured to control a first/second pull-down node to be electrically connected to, or electrically disconnected from, a second/first control voltage end under the control of a potential at a pull-up node. The pull-up node resetting circuit is configured to control the pull-up node to be electrically connected to the second control voltage end under the control of a potential at the first pull-down node, and control the pull-up node to be electrically connected to the first control voltage end under the control of a potential at the second pull-down node.