Touchscreen Panel Mesh Layout for Uniform Electrode Capacitance

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Solution Overview

Problem

Conventional touch display devices face challenges in achieving high touch sensitivity due to undesired differences in capacitance among touch electrodes, which can be exacerbated by variations in electrode size and shape, particularly in corner areas.

Innovation Solution

The implementation of a touchscreen panel with patterned mesh-type electrode metals, where dummy metals electrically disconnected from the electrode metal are strategically placed to maintain uniform capacitance across all areas, including corner regions with rounded outlines.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If touch electrodes are disposed with different sizes and shapes according to their positions, then the touchscreen panel can adapt to various layout requirements, but undesired differences in capacitance occur among touch electrodes, degrading touch sensitivity

Engineering Contradiction:

Improvelayout adaptabilityVSAvoidtouch sensitivity

Core Design Contradiction:

Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies local quality by introducing dummy metals with specific properties at different locations. Corner touch electrodes have dummy metals with first areas, while non-corner touch electrodes have dummy metals with second areas. This local differentiation compensates for the inherent capacitance differences caused by position-based size and shape variations, ensuring uniform touch sensitivity across the entire touchscreen panel.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the parameter of dummy metal area based on position. By adjusting the area of dummy metals (first area for corner electrodes, second area for non-corner electrodes), the capacitance values are equalized across different electrode positions. This parameter adjustment resolves the contradiction between layout adaptability and touch sensitivity.

Inventive Principle:

Principle #35Parameter changes

2Shape

If corner touch electrodes are made smaller to fit rounded corner areas, then the touchscreen panel can accommodate rounded outlines, but capacitance differences increase between corner and non-corner electrodes, reducing touch sensitivity

Engineering Contradiction:

Improverounded corner shapeVSAvoidtouch sensitivity

Core Design Contradiction:

ShapeVSReliability

Solution Approach 1:

The patent uses dummy metals as a counterweight mechanism. The dummy metals added to corner touch electrodes compensate for the capacitance reduction caused by their smaller size and rounded shape. This counterbalancing approach ensures that corner electrodes achieve capacitance values comparable to larger non-corner electrodes, maintaining uniform touch sensitivity across the panel.

Inventive Principle:

Principle #8Anti-weight (Counterweight)

Solution Approach 2:

The dummy metals are preliminarily configured with specific areas during the manufacturing process. By pre-calculating and pre-setting the dummy metal areas (first area for corner, second area for non-corner), the capacitance equalization is achieved before the touchscreen panel is deployed, ensuring consistent touch sensitivity from the outset.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If uniform touch electrode sizes are used across all positions, then capacitance uniformity is improved, but the touchscreen panel cannot adapt to rounded corner areas and various layout requirements

Engineering Contradiction:

Improvecapacitance uniformityVSAvoidlayout adaptability

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent segments the dummy metal configuration into different categories based on position. Corner touch electrodes receive dummy metals with first areas, while non-corner touch electrodes receive dummy metals with second areas. This segmentation allows the system to maintain capacitance uniformity while adapting to different layout requirements, including rounded corners and various electrode arrangements.

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 solution effectively prevents or removes undesired differences in capacitance among touch electrodes, thereby enhancing touch sensitivity and ensuring accurate capacitance-based touch sensing regardless of electrode size or shape variations.

Implementation Method 1

capacitance touch sensing is commonly used to sense a touch and determine touch coordinates using a plurality of touch electrodes disposed on a touchscreen panel, based on a change in capacitance between touch electrodes

Methodology Applied

Scientific EffectCapacitance: Capacitance

Data Source

PatentUS12204728B2Touch display device and touchscreen panel

Publication Date: 2025.01.21 LG DISPLAY CO LTD

AI summary

A touch display device and a touchscreen panel. Even in the case in which touch electrodes have different sizes or shapes or a located in different positions, a difference in capacitance is not formed among the touch electrodes. High touch sensitivity can be obtained. The touch display device comprises a plurality of touch electrodes, wherein a first touch electrode of the plurality of touch electrodes occupies a first area and comprises first mesh-shaped electrode metal. The touch display device comprises first dummy metal in a same layer as the first mesh-shaped electrode metal and in the first area occupied by the first touch electrode, the first dummy metal being electrically disconnected from the first mesh-shaped electrode metal.