Touch Electrode Layout Using a Dummy Electrode for Higher Sensitivity

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Solution Overview

Problem

Existing touch structures using metal meshes for touch electrodes face challenges in detection sensitivity due to low resistance and high sensitivity to subtle capacitance changes, leading to reduced detection accuracy and effectiveness.

Innovation Solution

Incorporating a dummy electrode at or near the intersection of touch driving and sensing electrodes to reduce the reference capacitance by blocking or redirecting electric field lines, thereby enhancing detection sensitivity and accuracy.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metal meshes are used for touch electrodes, then the touch structure achieves good electrical conductivity and transparency, but the detection sensitivity is reduced due to low resistance and high sensitivity to subtle capacitance changes

Engineering Contradiction:
Improveelectrical conductivityVSAvoiddetection sensitivity
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The dummy electrode acts as an intermediary element that mediates the electric field distribution between the touch driving electrode and touch sensing electrode. By introducing this intermediate structure, the patent reduces the reference capacitance and blocks harmful electric field lines, thereby improving detection sensitivity without compromising the electrical conductivity of the metal mesh electrodes

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent extracts and removes the harmful electric field lines that cause false capacitance changes by introducing the dummy electrode. The dummy electrode captures and redirects these spurious electric field lines, separating them from the useful signal path between the touch electrodes, thus improving measurement precision while maintaining the conductivity benefits of metal meshes

Inventive Principle:
Principle #2Taking out (Extraction)

2Stability of the object's composition

If the reference capacitance is high, then the touch structure has stable electrical connection, but the detection accuracy is reduced due to low proportion of capacitance change from finger touch

Engineering Contradiction:
Improveelectrical connection stabilityVSAvoiddetection accuracy
Core Design Contradiction:
Stability of the object's compositionVSMeasurement precision

Solution Approach 1:

The dummy electrode serves as a mediator that selectively interacts with electric field lines. It maintains stable electrical connection by providing a controlled reference capacitance while simultaneously blocking the harmful electric field lines that would otherwise create noise and reduce detection accuracy. This intermediary structure allows the system to achieve both stability and precision

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent converts the harmful effect of high reference capacitance (which causes low detection accuracy) into a beneficial reference standard. By using the dummy electrode to create a controlled, stable reference capacitance, the system transforms the previously problematic high reference capacitance into a useful baseline that improves detection accuracy while maintaining electrical connection stability

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

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

The dummy electrode improves detection sensitivity and accuracy by increasing the proportion of capacitance change caused by finger touch relative to the reference capacitance, thus enhancing the touch structure's detection performance.

Implementation Method 1

the dummy electrode is configured to be coupled with at least one selected from the group consisting of the first connection portion and the second connection portion through an electric field

Methodology Applied
Scientific EffectElectric field: Electric Field

Data Source

PatentEP4002073B1Touch structure, touch display panel, and electronic device
Publication Date: 2025.11.26 BOE TECHNOLOGY GROUP CO LTD
  • EP4002073B1 patent drawingFigure 1A~1B
  • EP4002073B1 patent drawingFigure 2A~2B
  • EP4002073B1 patent drawingFigure 3A

AI summary

A touch structure (20), a touch display panel (60) and an electronic apparatus (900) are provided. The touch structure (20) includes a first touch electrode (210) extended along a first direction (D1) and a second touch electrode (220) extended along a second direction (D2); the first touch electrode (210) includes first electrode main body portions (211) and a first connection portion (212), the first electrode main body portions (211) are in a first conductive layer (201) and the first connection portion (212) is in a second conductive layer (202); the second touch electrode (220) includes second electrode main body portions (221) and a second connection portion (222) in the first conductive layer (201); the first connection portion (212) is overlapped with the second connection portion (222) in a direction perpendicular to the first conductive layer (201); the first conductive layer (201) includes first metal meshes (213) formed by first metal lines (21), and the second conductive layer (202) includes second metal lines (22). The touch structure (20) also includes a dummy electrode (230) in the second conductive layer (202). The dummy electrode (230) is coupled with at least one of the first connection portion (212) and the second connection portion (222). The touch structure (20) can effectively improve the touch sensitivity.