Mutual-Capacitance Touch Screen Electrode Ratio Optimization
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Solution Overview
Problem
Mutual-capacitance touch screens face challenges in detecting slight capacitance variations in interfered environments, leading to poor signal-to-noise ratios and detection accuracy.
Innovation Solution
The design incorporates multiple parallel first and second electrodes coupled to a touch-sensitive processing apparatus, with a covering layer that adjusts thickness and permittivity to optimize the ratio between electrode distances and layer thickness, enhancing the signal-to-noise ratio by controlling fringe capacitance variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a mutual-capacitance touch screen is used, then touch detection capability is provided, but detection accuracy deteriorates in interfered environments due to poor signal-to-noise ratio
Solution Approach 1:
The patent applies parameter changes by optimizing the thickness of the covering layer and the distance between electrodes to specific ratio ranges. By adjusting these physical parameters, the fringe capacitance is controlled to enhance the signal-to-noise ratio, thereby improving detection accuracy in interfered environments without changing the fundamental mutual-capacitance detection mechanism.
2Strength
If the covering layer thickness is increased, then protection and structural integrity are improved, but fringe capacitance increases leading to reduced detection accuracy
Solution Approach 1:
The patent resolves this contradiction by establishing an optimal ratio range between the covering layer thickness and the electrode distance. This parameter optimization ensures that the covering layer provides sufficient structural protection while controlling the fringe capacitance to maintain high detection accuracy, preventing the trade-off from degrading performance.
3Manufacturing precision
If electrode distance is increased, then manufacturing tolerance is relaxed, but fringe capacitance increases reducing signal-to-noise ratio
Solution Approach 1:
The patent addresses this contradiction by defining an optimal ratio range between electrode distance and covering layer thickness. This allows the electrode distance to be increased for relaxed manufacturing tolerance while the proportional adjustment of covering layer thickness maintains the fringe capacitance control, thereby preserving the signal-to-noise ratio.
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 improves the signal-to-noise ratio, enabling better detection accuracy of external conductive objects on the screen, even in challenging environments, by optimizing the relationship between the covering layer's thickness, permittivity, and electrode distances.
Implementation Method 1
mutual-capacitance touch screen
Implementation Method 2
a thickness of the covering layer and a permittivity of the covering layer form a liner relationship
Data Source
AI summary
The present invention provides a mutual-capacitance touch screen comprising multiple parallel first electrodes and multiple parallel second electrodes coupled to a touch sensitive processing apparatus; and a covering layer for covering the first and the second electrodes, wherein a thickness of the covering layer and a third distance between one of the first electrodes and an adjacent second electrode form a third ratio range.