Touch Apparatus Stylus Detection Threshold Adjustment
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Solution Overview
Problem
Touch devices often fail to accurately detect the position of a stylus pen when a conductive object, such as a human body, is simultaneously contacted, due to interference in signal detection.
Innovation Solution
A touch device with a touch panel and a controller that applies different driving signals in various modes to distinguish between detection signals from a stylus pen and a conductive object, adjusting threshold values based on touch coordinates and patterns to accurately identify valid touch signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a single driving signal and threshold value are used for touch detection, then the detection system is simple, but the stylus pen touch position cannot be accurately detected when a conductive object is simultaneously contacted
Solution Approach 1:
The patent divides the touch detection process into multiple modes (first driving mode and second driving mode) with different driving signals and threshold values. The controller selectively applies different detection strategies based on the detected touch conditions, segmenting the detection task to handle stylus pen touches and conductive object touches separately, thereby improving accuracy without requiring a completely complex unified system.
Solution Approach 2:
The patent implements dynamic threshold value adjustment where the second threshold value is determined based on first detection signals. The system adapts the detection parameters in real-time based on the touch characteristics detected in the first mode, allowing the same hardware to dynamically optimize its detection accuracy for different touch scenarios without physical reconfiguration.
2Reliability
If different driving signals and threshold values are applied for different touch modes, then stylus pen touch detection accuracy improves, but the control and signal processing complexity increases
Solution Approach 1:
The patent employs feedback mechanisms where the controller uses first detection signals to determine the second threshold value. This feedback loop allows the system to learn from the initial detection results and adjust subsequent detection parameters, improving reliability while keeping the control logic manageable through iterative refinement rather than requiring complex predetermined rules for all scenarios.
Solution Approach 2:
The patent changes detection parameters (driving signal frequency and threshold values) based on detected touch conditions. By adjusting these parameters dynamically rather than using fixed complex processing rules, the system improves reliability for stylus pen detection while maintaining relatively simple control logic through parameter adaptation rather than algorithmic complexity.
3Measurement precision
If the threshold value is set high to avoid false positives, then false negative rates increase when conductive objects are present
Solution Approach 1:
The patent performs preliminary touch detection using a first driving signal and first threshold value before applying the second driving signal with adjusted threshold values. This preliminary action allows the system to identify basic touch conditions and determine appropriate subsequent detection parameters, preventing false negatives by ensuring that valid stylus pen touches are detected in the preliminary stage before more specific filtering is applied.
Solution Approach 2:
The controller uses feedback from first detection signals to determine appropriate second threshold values. This feedback mechanism allows the system to adapt the threshold dynamically based on the detected touch characteristics, preventing false negatives by adjusting the threshold downward when conductive objects are detected, while maintaining high accuracy through the feedback-driven adaptation process.
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
Enables precise detection of the stylus pen's position even when a conductive object is simultaneously contacted, improving touch data accuracy and preventing false negatives.
Implementation Method 1
the stylus pen generates a signal by resonating with the driving signal applied to the touch sensor, and the touch sensor detects a touch position by receiving a resonant signal of the stylus pen
Data Source
AI summary
A touch device includes: a touch panel including a plurality of touch electrodes; a driver/receiver for applying a first driving signal to the touch panel while driven in a first mode, and applying a second driving signal that is different from the first driving signal to the touch panel while driven in a second mode; and a controller for comparing first detection signals received from the touch panel with a first threshold value to obtain first touch data while driven in the first mode, and comparing second detection signals received from the touch panel with a second threshold value to obtain second touch data while driven in the second mode, wherein the controller determines the second threshold value based on at least part of the first detection signals.