Patterned Resistive Touch Panel Multi-Touch Detection

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Solution Overview

Problem

Existing touch panels cannot accurately determine the locations of multiple touch points simultaneously, limiting their functionality in applications requiring simultaneous input at multiple coordinates.

Innovation Solution

A touch panel design featuring two spaced component panels with a patterned resistive element, where the first panel provides a voltage to the resistive element at contact points, allowing measurement of voltage values to determine two-dimensional coordinates of each touch point, enabling detection of multiple touch points through a meandering resistive element pattern.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a conventional resistive touch panel with simple wire arrangements is used, then the device complexity is low, but the ability to determine multiple touch points simultaneously is lost

Engineering Contradiction:
Improvetouch point location determinationVSAvoidresistive element pattern
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The touch panel is divided into multiple independent touch areas, with each area having its own resistive element pattern. This segmentation allows each zone to independently detect touch points while maintaining overall system functionality, resolving the contradiction between measurement precision and device complexity by distributing the detection capability across separate segments.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent transitions from simple linear wire arrangements to two-dimensional meandering patterns of resistive elements. This dimensional expansion enables the detection of multiple touch points simultaneously across different spatial locations, achieving improved measurement precision while the systematic layout keeps device complexity manageable.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If parallel arranged electrodes are used to detect multiple touch points, then the quantity of detectable touch points increases, but the exact positions of contact points cannot be determined

Engineering Contradiction:
Improvecontact point positionVSAvoidmultiple touch point detection
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

Each touch area is equipped with locally optimized resistive element patterns that provide both positional resolution and multi-touch capability. The meandering design creates distinct voltage gradient patterns at different locations, enabling precise local position determination while maintaining the ability to detect multiple simultaneous touch points across different areas.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The resistive element patterns act as intermediaries between the touch contact points and the measurement system. These patterns convert physical touch positions into distinguishable voltage signals, allowing the system to simultaneously determine both the exact positions and the multiplicity of contact points through voltage measurement at the ends of the resistive elements.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If a meandering resistive element pattern is implemented, then multiple touch points can be detected with exact positions, but the manufacturing complexity increases

Engineering Contradiction:
Improvetwo-dimensional coordinates determinationVSAvoidpatterned resistive element fabrication
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The meandering resistive element pattern serves multiple functions simultaneously: it provides positional encoding, enables multi-touch detection, and creates distinguishable voltage gradients. This multi-functionality reduces the need for additional complex components, as the same patterned structure performs all detection functions, thereby improving ease of manufacture relative to the performance gains.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent uses parameter changes in the resistive element geometry (meandering patterns with specific pitch and amplitude) to achieve precise coordinate determination. By optimizing these geometric parameters, the system achieves high measurement precision while maintaining manufacturability through standardized pattern designs that can be produced using conventional fabrication techniques.

Inventive Principle:
Principle #35Parameter changes

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

Enables accurate determination of two-dimensional coordinates for multiple touch points, enhancing the panel's ability to handle simultaneous input events and improving user interaction with displayed information.

Implementation Method 1

the first panel provides an input voltage to the resistive element at each of the contact points

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP2249234B1Patterned resistive touch panel
Publication Date: 2014.10.08 AU OPTRONICS CORP
  • EP2249234B1 patent drawingFigure 1
  • EP2249234B1 patent drawingFigure 2a
  • EP2249234B1 patent drawingFigure 2b~3b

AI summary

A touch panel having a first panel and a second panel, wherein the first panel has a voltage providing area connected to a power source and the second panel has a patterned resistive element facing the voltage providing area so that when a touch event on the touch panel occurs, the first panel is caused to make contact with and provide a voltage to the second panel at one or more contact points on the resistive element. By measuring the voltage on one or both ends of the resistive element, it is possible to determine the two-dimensional coordinates of each contact point. The touch panel can have one or more resistive elements located at different touch areas for sensing one or more touch points in a touch event.