Stylus Pen Multi-Frequency Resonance Circuit for Touch Noise Reduction
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Solution Overview
Problem
Conventional touch sensors are vulnerable to noise interference due to resonant frequency matching with stylus pens, which hampers accurate touch input detection.
Innovation Solution
A stylus pen with multiple resonant frequencies and a touch apparatus that alternates between different driving frequencies to distinguish noise signals, improving signal-to-noise ratio and enabling precise touch position calculation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a resonance circuit is embedded in the stylus pen to enable sophisticated touch input, then the stylus pen can transmit signals to the touch sensor, but the touch sensor becomes vulnerable to noise at resonant frequencies
Solution Approach 1:
The patent applies frequency hopping by alternating between multiple resonant frequencies (first resonant frequency and second resonant frequency) in the resonance circuit portion of the stylus pen. This dynamic frequency switching prevents the touch sensor from being continuously exposed to noise at a single resonant frequency, thereby reducing noise interference while maintaining stylus functionality
Solution Approach 2:
The patent changes the operating frequency parameter of the resonance circuit portion by incorporating multiple resonance circuits with different resonant frequencies. The controller switches between these different frequencies to transmit signals to the touch sensor, transforming the system from a single-frequency operation to a multi-frequency hopping mode that avoids fixed-frequency noise interference
2Device complexity
If the touch sensor uses a fixed driving frequency to detect touch inputs, then the detection process is simple, but noise signals at the same frequency interfere with accurate touch detection
Solution Approach 1:
The controller dynamically switches between multiple driving frequencies (first driving frequency and second driving frequency) corresponding to different resonant circuits. By alternating frequencies in time, the system can distinguish between true touch signals and noise signals that persist at a single frequency, thereby improving detection accuracy without requiring complex filtering algorithms
Solution Approach 2:
The controller receives detection signals from the touch sensor at different frequencies and uses this feedback to determine whether a touch input occurred. By comparing signals at multiple frequencies, the system can identify genuine touch events versus noise, as noise typically appears at only one frequency while valid touch inputs can be detected across multiple frequency switches
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
Enhances reception sensitivity and accuracy of touch inputs by reducing noise interference through frequency hopping, allowing for improved touch position calculation and data transmission.
Implementation Method 1
a resonant circuit portion positioned in the body portion, electrically connected between the conductive tip and the ground portion, and including one or more resonance circuits that resonate with electrical signals of different frequencies transferred from the conductive tip to output resonance signals of different frequencies
Data Source
AI summary
An exemplary embodiment of the present invention provides a stylus pen including: a body portion; a conductive tip configured to be exposed from an inside of the body portion to an outside thereof; a ground portion configured to be electrically connected to a user; and a resonant circuit portion in the body portion, electrically connected between the conductive tip and the ground portion, and including one or more resonance circuits that resonate with electrical signals of different frequencies transferred from the conductive tip to output resonance signals of different frequencies.