Capacitive Detection Device for Pressure Sensing
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Solution Overview
Problem
Current touch control technologies, such as capacitive touch screens, struggle to accurately detect pressure changes, which limits the dimensions of input and affects user experience, as they fail to simulate the experience of using a real pen for writing.
Innovation Solution
A capacitive detection device comprising a differential amplifier, capacitors, a charging module, and a control module that calculates the capacitance difference between two capacitors, allowing for improved pressure detection sensitivity and accuracy by amplifying signals and outputting them to a calculation module.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional capacitive touch screen is used, then touch control function is provided, but pressure detection accuracy is insufficient
Solution Approach 1:
The detection device is segmented into multiple functional modules: charging module, differential amplifier module, and calculation module. Each module performs a specific function in the capacitance detection process, allowing for optimized design of each component while maintaining overall system functionality and improving pressure detection accuracy.
Solution Approach 2:
A differential amplifier is introduced as an intermediary component between the capacitors and the calculation module. The differential amplifier amplifies the voltage difference signal from the capacitors, enabling more accurate capacitance difference detection without requiring direct complex measurement circuitry.
2Loss of information
If capacitance difference detection is implemented, then pressure information can be obtained, but signal amplification is required increasing device complexity
Solution Approach 1:
The differential amplifier serves as an intermediary that bridges the gap between the small capacitance difference signal and the calculation module. It amplifies the voltage difference proportionally to the capacitance difference, making the signal suitable for further processing without loss of information.
Solution Approach 2:
The system changes the voltage parameter through the differential amplifier to reflect the capacitance difference. By amplifying the voltage difference signal, the system transforms an extremely small electrical signal into a more measurable parameter while maintaining the relationship between voltage and capacitance difference.
3Measurement precision
If pressure detection sensitivity is improved, then user experience is enhanced, but detection device complexity increases
Solution Approach 1:
The detection device is divided into specialized modules with distinct functions: the charging module handles capacitor charging, the differential amplifier module handles signal amplification, and the calculation module handles capacitance difference computation. This segmentation allows each module to be optimized for its specific function, improving overall sensitivity while managing complexity through modular design.
Solution Approach 2:
The patent replaces complex mechanical pressure sensing mechanisms with an electrical capacitance-based detection system. By using capacitive sensing combined with differential amplification, the system achieves high pressure detection sensitivity without requiring complex mechanical structures.
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 user experience by accurately detecting pressure changes, enabling more precise input and simulating the experience of using a real pen for writing, while also improving the sensitivity of pressure detection on touch screens and mobile devices.
Implementation Method 1
the differential amplifier is configured to amplify a signal and output the amplified signal from the first output terminal and the second output terminal to the calculation module
Implementation Method 2
in a first phase, the control module is configured to control the charging module to charge the third capacitor and the fourth capacitor
Data Source
AI summary
A capacitive detection device, a method and a pressure detection system are provided. The capacitive detection device includes a differential amplifier, a first capacitor, a second capacitor, a charging module, a control module and a calculation module. The charging module is controlled by the control module to charge two capacitors to be detected, then an amount of charge of the capacitors to be detected is transferred to the first capacitor and the second capacitor, and a signal is amplified through the differential amplifier and the amplified signal is output to the calculation module, so that a capacitance difference of different capacitors may be obtained through a voltage at an output terminal of the differential amplifier, a supply voltage of the charging module, a capacitance of the first capacitor and a capacitance of the second capacitor.