Capacitive Touch Noise Correction via Digital Signal Processing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Capacitive touch devices face challenges in maintaining operation sensitivity due to noise interference from sources like human static electricity and electronic devices, which complicates signal detection and requires costly signal reinforcement methods that may compromise the device's compact design.
Innovation Solution
A capacitive touch device with a sensing point matrix and a processing unit that calculates noise correction values based on sensing values obtained at similar time points, allowing for noise reduction and improved signal-to-noise ratio without altering the device's structure or increasing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If signal reinforcement methods (increasing driving voltage, shielding, filtering, grounding) are applied to reduce noise and maintain SNR, then operation sensitivity is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces physical noise reduction methods (shielding, filtering, grounding) with a digital signal processing approach. The processing unit calculates noise correction values based on sensing values obtained at substantially the same time point and uses these to correct sensing values, thereby eliminating the need for complex physical noise reduction structures.
Solution Approach 2:
The patent creates a digital copy of the noise characteristics by measuring sensing values at multiple time points and using these copies to calculate noise correction values. This allows the system to compensate for noise effects without physically blocking or filtering noise sources, thus avoiding increased structural complexity.
2Reliability
If signal reinforcement methods (increasing driving voltage, shielding, filtering, grounding) are applied to reduce noise and maintain SNR, then operation sensitivity is improved, but manufacturing cost increases
Solution Approach 1:
The patent replaces costly physical noise reduction components (shielding materials, filters, grounding systems) with software-based noise correction algorithms. The processing unit calculates noise correction values using sensing data and applies these to correct sensing values, achieving noise reduction without additional manufacturing costs.
Solution Approach 2:
The patent uses inexpensive digital processing operations to achieve noise reduction. Instead of investing in expensive physical noise reduction infrastructure, the system employs computational methods that can be implemented through software, significantly reducing manufacturing costs while maintaining noise reduction effectiveness.
3Reliability
If physical noise reduction methods (shielding, filtering, grounding) are applied to reduce noise, then SNR is improved, but the device can no longer meet light and compact design targets
Solution Approach 1:
The patent substitutes physical noise reduction structures with a digital signal processing system. The processing unit calculates noise correction values based on sensing values obtained at substantially the same time point and applies these corrections, achieving SNR improvement without adding physical components that would compromise compactness.
Solution Approach 2:
The patent moves noise reduction from the physical dimension to the digital signal processing dimension. Instead of physically blocking or filtering noise through structural modifications, the system processes noise characteristics in the digital domain, maintaining a compact physical structure while achieving effective noise reduction.
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 solution effectively corrects noise-affected sensing values, enhancing the device's ability to accurately detect touch events and maintain sensitivity while adhering to a light and compact design target.
Implementation Method 1
a capacitive touch panel, having a sensing point matrix formed by m driving lines and n sensing lines
Implementation Method 2
The driving control unit, coupled to the m driving lines, sequentially provides m driving signals to the m driving lines in m corresponding driving periods, respectively
Data Source
AI summary
A detection method for a capacitive touch device is provided. The detection method includes steps of: driving an Mth driving line among an m driving lines of the capacitive touch device, wherein M is a natural number smaller than or equal to m and greater than 1; selecting a plurality of sensing lines among n sensing lines; obtaining a plurality of sensing values by detecting voltage changes at the selected sensing lines; determining whether to perform a noise reduction operation on the sensing values; if yes, calculating respective differences between the sensing values and a baseline value, and generating a noise correction value corresponding to the sensing values by performing a statistical computation on the differences; and correcting the differences according to the noise correction value.