Capacitance Sensing Electrode Ranges for Accurate Hover Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing capacitance detection devices face challenges in accurately detecting proximity positions due to undefined resistance values of detection electrodes, leading to insufficient detection performance and reduced sensor detection ranges.
Innovation Solution
A capacitance detection device with a detection electrode having a resistance gradient between 5 kΩ to 270 kΩ and an active shield electrode with a capacitance of 30 pF to 130 pF, utilizing operational amplifiers and adjustment circuits to amplify voltage differences, enabling accurate detection of proximity positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the resistance value of the detection electrode is reduced to improve capacitance detection accuracy, then the capacitance detection value reduction decreases, but the device complexity increases due to the need for simulation and specification definition
Solution Approach 1:
The patent defines specific parameter ranges for the detection electrode resistance value (5 kΩ to 270 kΩ) and active shield electrode capacitance (30 pF to 130 pF) to optimize capacitance detection accuracy. By establishing these concrete parameter specifications, the patent resolves the contradiction by providing clear design guidelines that eliminate the need for repeated simulations while ensuring optimal detection performance within the defined ranges.
2Measurement precision
If the resistance value of the detection electrode is reduced to improve detection performance, then the capacitance detection value reduction decreases, but the detection electrode dimensions or material requirements become more stringent
Solution Approach 1:
The patent establishes a specific resistance value range (5 kΩ to 270 kΩ) for the detection electrode that balances detection accuracy with manufacturing feasibility. This parameter definition resolves the contradiction by providing a practical range that achieves optimal capacitance detection without requiring excessively low resistance values that would demand stringent manufacturing precision.
3Adaptability or versatility
If the capacitance between the detection electrode and active shield electrode is increased to improve detection range, then the detection performance improves, but the active shield electrode design becomes more complex
Solution Approach 1:
The patent defines a specific capacitance range (30 pF to 130 pF) for the active shield electrode that expands the detection range while maintaining manageable design complexity. By establishing this parameter boundary, the patent resolves the contradiction by providing a capacitance range that improves detection versatility without requiring excessively high capacitance values that would complicate the active shield electrode design.
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 device achieves precise detection of object proximity, including hover operations, by defining suitable resistance and capacitance ranges, ensuring accurate sensor detection and improved signal-to-noise ratio.
Implementation Method 1
a detection electrode configured to detect a capacitance between the detection electrode and the object
Implementation Method 2
a first operational amplifier configured to amplify a voltage difference between an inverting input terminal of the first operational amplifier and a non-inverting input terminal of the first operational amplifier
Data Source
AI summary
A capacitance detection device for detecting a capacitance between a detection electrode and an object in proximity to the detection electrode includes the detection electrode configured to detect a capacitance between the detection electrode and the object, an active shield electrode disposed in proximity to the detection electrode, a voltage output circuit for outputting an alternating voltage to be supplied to the active shield electrode, a first adjustment circuit for adjusting an amplitude of an alternating voltage output from the voltage output circuit, and a first operational amplifier for amplifying and outputting a voltage difference between an inverting input terminal thereof connected to one end of the detection electrode and a non-inverting input terminal thereof to which an alternating voltage adjusted by the first adjustment circuit is applied. The detection electrode has, between one end and the other end thereof, a resistance value from 5 kΩ to 270 kΩ.