Touch Controller Frequency Spreading for Noise Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Capacitive touch panels face noise interference issues that affect touch sensitivity and accuracy, leading to errors in position detection and registration of touch inputs.
Innovation Solution
A touch controller that generates a driving signal by spreading the frequency of an input signal to a first frequency higher and a second frequency lower than a preset carrier frequency, using a noise analysis circuit to adjust the dodging frequency and avoid in-band noise, thereby improving sensing sensitivity without changing the carrier frequency or increasing sensing time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If frequency spreading is applied to avoid in-band noise, then touch sensitivity is improved, but device complexity increases
Solution Approach 1:
The patent applies parameter changes by modifying the frequency characteristics of the driving signal. Specifically, it spreads the power spectral density of the driving signal across a broader frequency range, changing from a concentrated frequency to a distributed frequency pattern. This parameter transformation allows the system to avoid in-band noise while maintaining signal integrity, thereby improving touch sensitivity without requiring fundamental architectural changes to the device
Solution Approach 2:
The patent introduces an intermediary approach by using a noise analysis circuit that analyzes noise characteristics and dynamically adjusts the frequency spreading parameters. This intermediary component mediates between the driving signal transmitter and the touch panel, allowing the system to adapt to varying noise conditions and optimize performance without directly complicating the core touch sensing mechanism
2Object-affected harmful factors
If carrier frequency is changed to avoid noise, then noise interference is reduced, but signal integrity deteriorates
Solution Approach 1:
The patent segments the frequency spectrum by dividing the power spectral density of the driving signal across multiple frequency components rather than concentrating it at a single carrier frequency. This segmentation allows the system to distribute signal energy away from noisy frequency bands while maintaining overall signal integrity through the combined effect of multiple frequency components
Solution Approach 2:
The patent implements dynamics by making the frequency spreading characteristics adaptive rather than fixed. The noise analysis circuit continuously monitors noise levels and dynamically adjusts the frequency distribution of the driving signal, allowing the system to respond to changing noise conditions while preserving signal integrity through real-time optimization
Data Source
AI summary
A touch controller includes a driving signal transmitter and a sensing signal receiver. The driving signal transmitter is configured to generate a driving signal by spreading a frequency of an input signal to a first frequency and a second frequency. The first frequency is higher than a preset carrier frequency and the second frequency is less than the carrier frequency. The driving signal transmitter inputs the driving signal to a touch panel. The sensing signal receiver is configured to receive a sensing signal generated in the touch panel based on the driving signal and generate touch data based on the sensing signal.