Mutual Capacitive Touch Panel Meandering Electrodes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Mutual capacitive touch panels with dual-layer electrode structures face issues with high background capacitance due to the thin film and optical adhesive used between sensing and driving series, leading to reduced touch sensing quality and increased stress when bent, which can cause fractures.
Innovation Solution
A mutual capacitive touch panel design featuring a first electrode layer, a second electrode layer, and an insulation layer, where the second electrode layer is closer to the touch object, and meandering electrode strips are used to reduce coupling capacitance and background capacitance by avoiding connecting line segments, thereby improving touch accuracy and reducing stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If thin film and optical adhesive are used between sensing series and driving series, then the touch panel can be manufactured with bonded layers, but the overall thickness increases to 100 μm or more causing excessive stress and easy fracture when bent
Solution Approach 1:
The patent removes the optical adhesive layer from between the sensing electrode layer and driving electrode layer, keeping only the thin film substrate. This extraction of the harmful element (optical adhesive) reduces overall thickness and eliminates the stress concentration that causes fracture during bending, while manufacturing is still achieved through thin film deposition processes.
2Length of stationary object
If insulation thickness between sensing series and driving series is reduced, then the overall thickness is reduced, but the background capacitance between sensing series and driving series is increased causing amplifier saturation and degraded sensing quality
Solution Approach 1:
The patent introduces a ground electrode layer positioned between the sensing electrode layer and driving electrode layer. This segmentation creates multiple isolated conductive layers that reduce capacitive coupling between sensing and driving electrodes. The ground layer acts as a shielding layer that divides the electric field, thereby reducing background capacitance while maintaining thin overall thickness.
Solution Approach 2:
The ground electrode layer serves as an intermediary element between the sensing and driving electrodes. It mediates the electric field interaction by providing a reference potential that reduces parasitic capacitance coupling, allowing thin insulation while maintaining low background capacitance and high sensing accuracy.
3Device complexity
If dual-layer electrode structure is used, then the structure design and control algorithm are simpler, but the background capacitance is high due to thin film and optical adhesive between layers
Solution Approach 1:
The dual-layer electrode structure is enhanced by segmenting it into four distinct layers: sensing electrode layer, ground electrode layer, driving electrode layer, and common electrode layer. This segmentation isolates the capacitive interactions, reducing background capacitance while preserving the structural simplicity and manufacturing advantages of the dual-layer approach.
Solution Approach 2:
The ground electrode layer acts as an intermediary that reduces harmful capacitive coupling between the sensing and driving electrodes. This intermediary layer maintains the simple dual-layer structural design while eliminating the background capacitance issue that would otherwise require complex compensation algorithms.
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 design effectively reduces background capacitance and stress on the touch panel, enhancing touch sensing quality and preventing fractures, while maintaining high accuracy even when bent.
Implementation Method 1
The insulation layer is disposed between the first electrode layer and the second electrode layer
Implementation Method 2
meandering electrode strips are used to reduce coupling capacitance and background capacitance by avoiding connecting line segments
Data Source
AI summary
A mutual capacitive touch panel includes a first electrode layer and a second electrode layer. The first electrode layer includes a plurality of first electrode series and a plurality of second electrode series. The second electrode layer includes a plurality of electrode strips, and each electrode strip crosses the first electrode series and the second electrode series. Each first electrode series includes a plurality of first electrodes and a plurality of second electrodes electrically connected with each other, and each first electrode and a corresponding one of the second electrodes are disposed abreast and form an electrode set. Each second electrode series includes a plurality of third electrodes electrically connected with each other, and each electrode set and each third electrode are arranged alternately along a direction.