Touch Sensor Frequency Tuning for Passive Stylus Detection
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Solution Overview
Problem
Existing electronic devices face challenges in accurately detecting and recognizing passive stylus pens due to difficulties in touch recognition, particularly in achieving a resonance frequency that maximizes signal amplitude for both active and passive stylus pens during charging and touch interactions.
Innovation Solution
An electronic device and control method that involve a touch sensor transmitting electromagnetic signals with multiple frequencies to a stylus pen and a touch controller determining the optimal frequency based on signal magnitude, allowing for improved touch data generation and reception sensitivity, even when the resonance frequency changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a passive stylus pen is used to reduce cost and eliminate battery requirements, then manufacturing cost and simplicity are improved, but touch recognition accuracy and signal detection capability deteriorate
Solution Approach 1:
The patent applies parameter changes by transmitting electromagnetic signals at multiple different frequencies to the stylus pen and detecting which frequency produces the strongest resonance response. This allows the system to adapt to variations in the passive stylus pen's resonant characteristics and achieve accurate touch recognition without requiring active electronic components in the stylus.
Solution Approach 2:
The system dynamically adjusts the detection frequency based on real-time feedback from the stylus pen's resonance response. By sequentially testing multiple frequencies and identifying the optimal resonance frequency, the system maintains high touch recognition accuracy despite using a simple passive stylus pen design.
2Measurement precision
If electromagnetic signals with multiple frequencies are transmitted to detect resonance frequency, then touch recognition accuracy is improved, but signal transmission time and processing complexity increase
Solution Approach 1:
The patent segments the frequency detection process into discrete sequential steps, where electromagnetic signals are transmitted at different frequencies in sequence rather than simultaneously. This allows the system to efficiently identify the resonance frequency by testing individual frequency points and stopping once the optimal frequency is found, reducing overall processing time.
3Adaptability or versatility
If the resonance frequency of the stylus pen changes due to environmental factors, then adaptability is improved, but signal magnitude and detection stability deteriorate
Solution Approach 1:
The system employs feedback by continuously monitoring the magnitude of the electromagnetic signal received from the stylus pen at different frequencies. Based on this feedback, the system identifies the frequency that produces the strongest response and adjusts subsequent transmissions to use this optimal frequency, maintaining stable and reliable signal detection even when resonance characteristics change.
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 the magnitude of the signal output from the stylus pen, improves touch input reception sensitivity, and accurately calculates touch positions, addressing the limitations of existing technologies in recognizing passive stylus pens.
Implementation Method 1
a touch sensor configured to sequentially transfer an electromagnetic signal having two or more frequencies to a stylus pen, and to receive the electromagnetic signal corresponding to the electromagnetic signal from the stylus pen
Implementation Method 2
a touch controller configured to operate the touch sensor by determining one of the two or more frequencies as the frequency of the electromagnetic signal depending on a change in the received electromagnetic signal
Data Source
AI summary
An embodiment of the present invention provides a display device including: a touch sensor configured to sequentially transfer an electromagnetic signal having two or more frequencies to a stylus pen, and to receive an electromagnetic signal corresponding to the electromagnetic signal from the stylus pen; and a touch controller configured to operate the touch sensor by determining one of the two or more frequencies as the frequency of the electromagnetic signal depending on a change in the received electromagnetic signal.