Capacitive Touch Panel Noise Reduction via Frequency Spectrum Correction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Capacitance type touch panels are prone to malfunctions due to noise generated by the display, which affects the accuracy of touch position detection, and existing solutions like rear surface shielding electrodes increase costs.
Innovation Solution
A touch panel design that includes scanning and detection electrodes, with a signal processing method involving continuous drive pulses, Fourier transforms, and inverse Fourier transforms to generate and correct frequency spectra, allowing for noise reduction without a shielding electrode on the display side.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a rear surface shielding electrode is provided to reduce noise generated by the display, then anti-noise performance is improved, but manufacturing cost increases
Solution Approach 1:
The invention extracts and removes the rear surface shielding electrode from the touch panel structure. Instead of using a separate shielding electrode layer, the patent achieves noise reduction through signal processing techniques (Fourier transform and pulse extraction) that eliminate the need for the additional electrode component, thereby reducing manufacturing cost while maintaining anti-noise performance
Solution Approach 2:
The invention replaces the physical/m structural shielding approach (shielding electrode) with a signal processing approach (Fourier transform and pulse extraction). This substitution transitions from a hardware-based noise reduction method to a software/signal-based method, eliminating the need for additional physical components and reducing manufacturing complexity
2Ease of manufacture
If signal processing is improved to reduce noise without shielding electrodes, then manufacturing cost decreases, but signal processing complexity increases
Solution Approach 1:
The invention applies periodic action by extracting pulses at different intervals from the continuous detection pulse train. By using periodic pulse extraction with different periods to generate multiple data sequences, the system can identify and correct noise patterns through their periodic characteristics, managing processing complexity through structured periodic operations
Solution Approach 2:
The invention changes parameters by performing Fourier transform on data sequences extracted at different intervals. This transforms the signal from time domain to frequency domain, where noise can be identified and corrected by comparing frequency components. The parameter change from time-domain sampling to frequency-domain analysis manages complexity through mathematical transformation
3Measurement precision
If noise reduction techniques are applied, then touch position detection precision is improved, but processing time increases
Solution Approach 1:
The invention applies preliminary action by pre-processing the detection signal through pulse extraction at different intervals before final analysis. By extracting and organizing data sequences in advance with different sampling intervals, the system prepares the signal for efficient Fourier transform and noise correction, reducing the processing time required during actual touch detection operations
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 approach enhances anti-noise performance, improving the signal-to-noise ratio and enabling precise touch position detection while reducing costs by eliminating the need for a rear surface shielding electrode.
Implementation Method 1
performing Fourier transform on each of the at least two data sequences to generate a frequency spectrum of the each of the at least two data sequences
Data Source
AI summary
Provided is a touch panel with improved anti-noise performance. A continuous drive pulse train is input to a plurality of scanning electrodes for each one scanning period in turns, and a detection pulse train generated at detection electrodes which intersects the scanning electrodes is detected. The detection pulse train is sampled at different intervals to generate a plurality of data sequences. The plurality of data sequences may be generated from the detection pulse train over a plurality of frame periods. A signal strength of each frequency component is compared between the frequency spectra of the plurality of data sequences, and a frequency spectrum in which frequency components having different strengths have been corrected is generated. A detection signal is generated from the corrected frequency spectrum.