Capacitive Touch Panel Circuit Segmentation for Impedance Reduction

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Solution Overview

Problem

Conventional capacitive touch panels have high impedance circuit patterns that weaken touch signals, leading to inaccurate determination of touch location and decreased reliability.

Innovation Solution

The circuit pattern is modified by dividing it into several electrode sensing blocks with low impedance metal leads connected in parallel, reducing signal transmission impedance and enhancing signal efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional circuit pattern with continuous ITO or ATO coating is used, then the touch panel can detect touch input, but the impedance is large which weakens the touch signal and reduces reliability

Engineering Contradiction:
Improvetouch signal reliabilityVSAvoidimpedance
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The continuous circuit pattern is divided into multiple discrete electrode sensing blocks arranged in series. Each block is separated by non-conductive regions, creating a segmented structure that reduces overall impedance while maintaining touch detection capability across the panel surface.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Multiple electrode sensing blocks are electrically connected in parallel through conductive leads to create an equivalent circuit with reduced impedance. The parallel configuration combines the conductive paths of individual blocks, lowering the total impedance presented to the touch signal.

Inventive Principle:
Principle #5Merging (Combining)

2Measurement precision

If a continuous circuit pattern is used, then the manufacturing process is simple, but the signal transmission accuracy is reduced due to high impedance

Engineering Contradiction:
Improvetouch location accuracyVSAvoidcircuit pattern complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The circuit pattern is segmented into multiple electrode sensing blocks with defined conductive and non-conductive regions. This segmentation improves touch location accuracy by creating distinct sensing zones while the systematic arrangement maintains manufacturing feasibility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The electrical parameters of the circuit pattern are modified by changing from a continuous high-impedance structure to a segmented parallel configuration. This parameter change reduces impedance and improves signal transmission accuracy without requiring fundamentally new manufacturing processes.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If the circuit pattern impedance is high, then the material coating can be continuous and simple, but the touch signal is weakened and transmission efficiency is reduced

Engineering Contradiction:
Improvesignal transmission efficiencyVSAvoidimpedance
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

Multiple electrode sensing blocks are merged into a parallel electrical configuration, combining their conductive pathways. This merging effect reduces the equivalent impedance and increases signal transmission efficiency while maintaining the segmented physical structure for accurate touch detection.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The continuous conductive layer is segmented into discrete electrode blocks that are electrically paralleled. This segmentation combined with parallel connection reduces the overall impedance presented to the touch signal, improving transmission efficiency without sacrificing detection accuracy.

Inventive Principle:
Principle #1Segmentation

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 design improves the accuracy and reliability of touch signal transmission by reducing impedance, allowing for precise determination of touch location and increased efficiency of capacitive sensing signals.

Implementation Method 1

The electrode sensing block and the low impedance metal lead are stacked together and electrically connected in parallel, utilizing the electrical conduction property to reduce signal transmission impedance

Methodology Applied
Scientific EffectElectrical Conduction: Conduction (electrical)

Implementation Method 2

When the human finger touches on the capacitive touch panel, the human finger will absorb a little current from the touch panel and the touch panel will calculate the percentage of the absorbed current to find the X-axis Y-axis coordinate of the touch location

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP2413222B1Circuit structure of capacitive touch panel
Publication Date: 2018.09.12 TPK TOUCH SOLUTIONS (XIAMEN) INC
  • EP2413222B1 patent drawingFigure 1A~1B
  • EP2413222B1 patent drawingFigure 2A~2B
  • EP2413222B1 patent drawingFigure 3A~3B

AI summary

A circuit pattern for capacitive touch panel is disclosed herein. The circuit pattern for capacitive touch panel includes a plurality of metal leads and a plurality of electrode sensing blocks. Those electrode sensing blocks are isolated to each other and electrically connected to the metal leads. The electrode sensing blocks will output a plurality of capacitive signals in accordance with a plurality of touch positions. According to the electrode pattern structure described above, the impedance of the electrode pattern can be decreased and the efficiency of the signal transmission can be improved and the sensibility of the touch panel can be increased.