Liquid Crystal Display Shield Wiring for Ion Accumulation

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Solution Overview

Problem

Liquid crystal display devices experience image persistence due to ion accumulation, leading to non-uniformity and afterimages, especially when displaying certain patterns like stripes for extended periods, which degrades image quality.

Innovation Solution

The implementation of shield wirings over video signal lines, formed using conductive materials like ITO and common metal wiring, with precise alignment and symmetry to minimize ion flow and accumulation, ensuring uniform potential distribution across the liquid crystal layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If video signal lines are used to supply image signals to pixel electrodes, then image signals can be transmitted efficiently, but ion accumulation occurs near the video signal lines causing image persistence and non-uniformity

Engineering Contradiction:

Improveimage signal transmission efficiencyVSAvoidion accumulation and image persistence

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

A shield wiring is introduced as an intermediary element between the video signal line and the liquid crystal layer. The shield wiring, connected to the common electrode, acts as a mediator that intercepts and redirects electric field lines, preventing direct interaction between the video signal line's electric field and the liquid crystal molecules, thereby suppressing ion accumulation while preserving signal transmission

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention converts the harmful electric field from the video signal line into a beneficial configuration by introducing the shield wiring. The electric field that would otherwise cause ion accumulation is now confined and redirected by the shield wiring, creating a more uniform potential distribution in the liquid crystal layer and actually improving display uniformity

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

2Duration of action of stationary object

If the same image is displayed for a long time, then display duration is maintained, but ion accumulation causes image persistence and deteriorates image quality

Engineering Contradiction:

Improvedisplay durationVSAvoidimage quality consistency

Core Design Contradiction:

Duration of action of stationary objectVSReliability

Solution Approach 1:

The shield wiring is positioned and configured in advance to preemptively counteract the formation of strong electric fields that would cause ion accumulation. By establishing this protective structure before displaying images, the system prevents image persistence from occurring even during prolonged display of static images, maintaining reliable image quality throughout the display duration

Inventive Principle:

Principle #9Preliminary anti-action

3Ease of manufacture

If conductive wirings are formed over video signal lines with asymmetric positioning, then manufacturing is simplified, but potential distribution becomes non-uniform causing display non-uniformity

Engineering Contradiction:

Improveconductive wiring formationVSAvoidpotential distribution uniformity

Core Design Contradiction:

Ease of manufactureVSManufacturing precision

Solution Approach 1:

The invention deliberately introduces asymmetric elements in the shield wiring configuration. The shield wiring is positioned at different distances from the video signal line on opposite sides, creating an asymmetric structure that, counterintuitively, produces a more uniform potential distribution in the liquid crystal layer by balancing the electric field interactions

Inventive Principle:

Principle #4Asymmetry

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution effectively suppresses ion flow and accumulation, reducing image persistence and maintaining high-quality image display by shielding the influence of video signal lines and balancing potential differences between shield wirings and video signal lines.

Implementation Method 1

conductive wirings are formed over the video signal lines via an organic insulating film in a plan view... an amount that the conductive wiring protrude the video signal line in a plan view is essentially the same in both sides of the video signal line

Methodology Applied

Scientific EffectElectromagnetic shielding: Faraday Cage

Data Source

PatentUS10191336B2Liquid crystal display device that avoids influence on image quality due to residual ions

Publication Date: 2019.01.29 MAGNOLIA WHITE CORP

AI summary

The purpose of the invention is to suppress image persistence. The structure if the invention is as follows: A liquid crystal display device comprising: scanning lines extending in a first direction and arranged in a second direction, video signal lines arranged to cross the scanning lines, a pixel area is surrounded by the scanning lines and the video signal lines, a pixel electrode is formed in the pixel area, wherein conductive wirings are formed over the video signal lines via an organic insulating film in a plan view in the display area where images are displayed, a width in the first direction of the conductive wiring is bigger than a width in the first direction of the video signal line, an amount that the conductive wiring protrude the video signal line in a plan view is essentially the same in both side of the video signal line.