Touch Panel Electrode Spacing for Linearity
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Solution Overview
Problem
Conventional capacitive touch panels face poor sensing linearity due to insufficient overlap between adjacent signals when the spacing between electrode series is increased to enhance sensitivity, leading to inaccurate calculation of touch points, especially when drawing straight lines.
Innovation Solution
The touch panel design includes intersecting driving and sensing electrode series with varying spacings, where the second electrode spacing in the surrounding region is smaller than the first in the center region, optimizing the overlap of adjacent signals for improved linearity and sensitivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the spacing between the first electrode series and the second electrode series is increased to strengthen the sensed signal, then the sensing sensitivity is improved, but the sensing linearity deteriorates due to insufficient overlap between adjacent sensed signals
Solution Approach 1:
The patent applies local quality by differentiating the electrode spacing into two distinct regions: a first electrode spacing in the center region and a second electrode spacing in the surrounding region. This allows the touch panel to have different spacing characteristics in different areas, optimizing both sensitivity and linearity for their respective functions.
Solution Approach 2:
The sensing area is segmented into a center region and a surrounding region with different electrode spacing configurations. This segmentation enables independent optimization of each region's characteristics, with the center region optimized for sensitivity and the surrounding region optimized for maintaining signal overlap and linearity.
2Power
If the spacing between electrode series is increased to enhance capacitance variation signal, then the sensed signal strength is improved, but the ability to correctly calculate touch coordinates deteriorates
Solution Approach 1:
Different electrode spacing is applied to different regions: the center region uses a first spacing optimized for maximizing capacitance variation signal, while the surrounding region uses a second spacing that ensures sufficient signal overlap for accurate coordinate calculation through interpolation.
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 enhances the sensing linearity and sensitivity of the touch panel by ensuring sufficient overlap between adjacent signals, allowing accurate calculation of touch points and maintaining strong capacitance variation signals.
Implementation Method 1
the capacitance between the first electrode series and the second electrode series may be varied, and such a variation signal is transmitted to a controller, and then a coordinate of the touched position is calculated
Data Source
AI summary
A touch panel including a substrate, a plurality of driving electrode series and a plurality of sensing electrode series is provided. The plurality of driving electrode series extending along a first direction is disposed on the substrate. The plurality of sensing electrode series extending along a second direction different from the first direction is disposed on the substrate. The plurality of driving electrode series and the plurality of sensing electrode series are intersected to constitute a plurality of sensing units, in which each sensing unit has a center region and a surrounding region. A first electrode spacing is formed between the driving electrode series and the sensing electrode series disposed in the center region, and a second electrode spacing is formed between the driving electrode series and the sensing electrode series disposed in the surrounding region. The second electrode spacing is smaller than the first electrode spacing.