Touchscreen Panel Electrode Layout for Uniform Touch Sensitivity

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Solution Overview

Problem

Conventional touch display devices face issues with touch sensitivity due to undesired differences in capacitance among touch electrodes, which can be caused by variations in size, shape, and position, leading to inconsistent touch detection and accuracy.

Innovation Solution

The implementation of a touchscreen panel with patterned mesh-type electrode metals and strategically placed dummy metals, where dummy metals are electrically disconnected from the electrode metal and located on the same layer, helps in reducing capacitance differences by adjusting the ratio of dummy metals in corner areas and using different shapes and sizes of touch electrodes to maintain uniform touch sensitivity across all areas.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If touch electrodes have different sizes due to shapes and locations, then the touchscreen panel can cover various positions, but undesired differences in capacitance are caused, degrading touch sensitivity

Engineering Contradiction:
Improvecoverage of touchscreen panelVSAvoidtouch sensitivity
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies local quality by introducing dummy electrodes with different configurations at different locations. Corner touch electrodes have dummy electrodes configured to increase their capacitance, while non-corner touch electrodes have dummy electrodes configured differently. This local differentiation compensates for the inherent capacitance differences caused by varying electrode sizes and positions, ensuring uniform touch sensitivity across the entire touchscreen panel.

Inventive Principle:
Principle #3Local quality

2Ease of manufacture

If corner touch electrodes are smaller than non-corner touch electrodes, then the touchscreen panel layout is optimized, but capacitance differences between corner and non-corner electrodes increase, reducing touch detection accuracy

Engineering Contradiction:
Improvetouchscreen panel layoutVSAvoidtouch detection accuracy
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent uses the dummy electrodes as a counterweight mechanism. For corner touch electrodes, dummy electrodes are strategically placed and configured to add capacitance that counterbalances the smaller physical size of corner electrodes. This compensation ensures that corner electrodes achieve capacitance values comparable to larger non-corner electrodes, thereby maintaining uniform touch detection accuracy across the panel.

Inventive Principle:
Principle #8Anti-weight (Counterweight)

3Reliability

If dummy metals are added to increase capacitance of corner electrodes, then capacitance differences are reduced, but device complexity increases

Engineering Contradiction:
Improvecapacitance uniformityVSAvoidelectrode structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the dummy electrodes with the same conductive material layer as the touch electrodes, forming them simultaneously in the same manufacturing process. This integration approach allows both functional electrodes and compensating dummy electrodes to be created as a unified structure, reducing the need for additional processing steps and minimizing the increase in device complexity while achieving capacitance uniformity.

Inventive Principle:
Principle #5Merging (Combining)

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 enhances touch sensitivity by minimizing capacitance variations, ensuring accurate and consistent touch detection regardless of electrode position, shape, or size, thereby improving the overall performance of touch display devices.

Implementation Method 1

desirably reduce differences in capacitance between corner areas and non-corner areas

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP4006704B1Touch display device and touchscreen panel
Publication Date: 2024.09.11 LG DISPLAY CO LTD
  • EP4006704B1 patent drawingFigure 1
  • EP4006704B1 patent drawingFigure 2
  • EP4006704B1 patent drawingFigure 3

AI summary

A touch display device comprising a touchscreen panel including a corner region, an edge region, and an inner region; and a touch sensor that includes respective portions corresponding to the corner region, the edge region, and the inner region of the touchscreen panel and having different sizes, wherein a size of an area in which the portion of the touch sensor corresponding to the corner region overlaps a display driving electrode is different from a size of an area in which the portion of the touch sensor corresponding to the edge region overlaps the display driving electrode or a size of an area in which the portion of the touch sensor corresponding to the inner region overlaps the display driving electrode.