Touch Panel System Pressing Force Detection Amplification
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Solution Overview
Problem
The electrostatic capacitance type touch panel systems with a cover member suffer from reduced detection sensitivity of pressing force due to the decreased change in electrostatic capacitance between the drive and pressing force sense electrodes, which hampers accurate force detection.
Innovation Solution
Incorporating a controller that amplifies signal values from the pressing force detection electrodes, allowing for improved detection sensitivity by enhancing the signal values within the pressing force detection range, thereby accurately calculating the pressing force even with a cover member present.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a cover member is provided to prevent damage to the touch panel, then reliability is improved, but detection sensitivity of pressing force decreases
Solution Approach 1:
The patent applies parameter changes by modifying the electrical characteristics of the touch panel system. Specifically, it changes the capacitance values of the detection electrodes and adjusts the detection algorithm parameters to compensate for the signal attenuation caused by the cover member, thereby maintaining detection sensitivity while preserving the protective function.
Solution Approach 2:
The patent implements feedback mechanisms by continuously monitoring the capacitance changes between the drive electrode and pressing force sense electrode, and adjusting the detection thresholds and signal processing parameters based on the detected pressing force magnitude. This feedback loop enables accurate force detection despite the presence of the cover member.
2Reliability
If a cover member is provided to prevent damage to the touch panel, then reliability is improved, but change amount of electrostatic capacitance decreases
Solution Approach 1:
The patent compensates for the reduced capacitance change by adjusting the detection sensitivity parameters and signal amplification factors. The system modifies its operational parameters to detect smaller capacitance variations that occur when a cover member is present, effectively counteracting the reduction in capacitance change amount.
Solution Approach 2:
The patent introduces signal processing intermediaries including amplification stages and filtering algorithms that enhance the weak capacitance change signals. These intermediary processing steps bridge the gap between the reduced physical capacitance change and the required detection threshold, enabling accurate measurement despite the cover member's dampening effect.
3Measurement precision
If signal values are amplified in pressing force detection range, then detection sensitivity is improved, but device complexity increases
Solution Approach 1:
The patent applies partial action by selectively amplifying only the signal values within the pressing force detection range rather than amplifying all signals. This targeted approach achieves the necessary detection sensitivity improvement while minimizing the added complexity, as the amplification is applied only where needed in the signal processing pipeline.
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
The amplification of signal values in the pressing force detection range significantly enhances the detection sensitivity of the touch panel system, ensuring accurate and precise force detection despite the presence of a cover member.
Implementation Method 1
electrostatic capacitance between the drive electrode and the pressing force sense electrode increases, and a signal from the pressing force sense electrode changes. The magnitude of a pressing force is determined based on the change in the signal from the pressing force sense electrode.
Data Source
AI summary
A touch panel system includes a touch panel, a cover member overlapping the touch panel, and a controller. The controller includes a position detection unit configured to detect a position of a pointer, based on a signal value obtained from a position detection electrode, an amplification processing unit configured to perform amplification processing on at least one signal value in a pressing force detection range corresponding to the position of the pointer detected by the position detection unit among signal values obtained from a pressing force detection electrode, and a pressing force detection unit configured to calculate magnitude of a pressing force generated by the pointer, based on a signal value after the amplification processing being a signal value in the pressing force detection range including a signal value obtained by amplification by the amplification processing unit.