Capacitance Sensor Electrostatic Shielding for Disturbance Reduction
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Solution Overview
Problem
Capacitance sensors with elastically deformable dielectrics face interference from disturbance capacitance between wiring lines and electrodes, which degrades measurement accuracy.
Innovation Solution
Incorporating a grounded electrostatic shielding member between wiring lines and electrodes to minimize disturbance capacitance by positioning it in strategic locations where wiring lines move relative to electrodes during elastic deformation, ensuring it does not overlap with the electrodes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a wiring line is connected to each electrode to measure capacitance, then capacitance measurement becomes possible, but disturbance capacitance between wiring lines and electrodes interferes with measurement accuracy
Solution Approach 1:
The patent introduces a grounded electrostatic shielding member as an intermediary between the wiring lines and the electrodes. This shielding member acts as a mediator that intercepts and redirects electric field lines, preventing direct capacitive coupling between the wiring lines and electrodes. The grounded shield effectively isolates the measurement circuit from the sensor electrodes, eliminating the disturbance capacitance while allowing the wiring lines to remain connected for capacitance measurement.
Solution Approach 2:
The patent extracts the harmful disturbance capacitance from the measurement system by introducing a separate grounded shielding structure. The electrostatic shield is positioned between the wiring lines and electrodes to physically and electrically separate the measurement circuit from the sensor elements, removing the parasitic capacitance effect from the measurement path while preserving the intended capacitance measurement between electrodes.
2Measurement precision
If an electrostatic shielding member is arranged between wiring lines and electrodes, then disturbance capacitance is reduced, but device complexity increases
Solution Approach 1:
The patent employs a thin film-shaped electrostatic shielding member that can be easily integrated into the sensor structure. This flexible, film-like shield conforms to the sensor geometry and can be deposited or attached as a thin layer between the wiring lines and electrodes, minimizing structural complexity while effectively providing electrostatic shielding. The thin film approach avoids bulky shielding structures and maintains the compactness of the original sensor 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
Significantly reduces disturbance capacitance to improve measurement accuracy of the capacitance between electrodes, allowing for precise detection of elastic deformation and external forces.
Implementation Method 1
a grounded electrostatic shielding member is arranged in at least one or more of a place between a first wiring portion of the first electrode-side wiring line that moves relative to the second electrode together with the first electrode as the base material elastically deforms and the second electrode
Implementation Method 2
an elastically deformable base material formed of a dielectric
Data Source
AI summary
A capacitance sensor 1A in which first electrodes 3(1) to 3(4) and a second electrode 4 are arranged on a base material 2 made of a dielectric includes grounded electrostatic shielding members (5(1) to 5(6)). The electrostatic shielding members 5 are arranged, for example, at positions between first wiring portions 6(1)in, 6(2)in, 6(4) in connected to the first electrodes 3(1), 3(2), 3(4) and the second electrode 4, at a position between a second wiring portion 6(5)in connected to the second electrode 4 and the first electrode 3(4), and at a position between the second wiring portion 6(5)in and the first wiring portion 6(4)in.