Capacitive Sensor Using Bent Conductor for Force Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing force sensors, such as capacitive sensors, face challenges in accurately measuring force applied to displays due to displacement variations, which are not effectively addressed in detecting changes in distance between elements.
Innovation Solution
A sensor system utilizing a bent conductor between two elements, where the self-capacitance caused by the conductor's bend diameter corresponds to displacement, allowing for force measurement through signal analysis and processing, enabling digital or analog detection of force applied to a display.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a conventional capacitive sensor measures displacement between parallel plates, then force sensing capability is achieved, but measurement precision deteriorates due to displacement variations not being effectively addressed
Solution Approach 1:
The patent changes the measurement parameter from direct displacement between parallel plates to self-capacitance of a bent conductor, where the capacitance value directly reflects the bend diameter and thus the applied force, eliminating the need to account for variable displacement distances
Solution Approach 2:
The patent replaces the mechanical parallel plate displacement measurement system with an electrical self-capacitance measurement system, where the conductor's own capacitance serves as the measurement parameter, transforming a mechanical measurement problem into an electrical one that is more precise and reliable
2Measurement precision
If a bent conductor is used to measure displacement through self-capacitance, then measurement precision improves, but device complexity increases due to additional signal processing requirements
Solution Approach 1:
The conductor itself serves dual purposes: it is both the structural element that deforms under force and the sensing element whose self-capacitance is measured. This self-service approach eliminates the need for separate measurement infrastructure, reducing overall system complexity despite the sophisticated measurement technique
Solution Approach 2:
The bent conductor performs multiple functions simultaneously: it acts as a mechanical element connecting components, a structural element that deforms with applied force, and a sensing element whose electrical capacitance provides the measurement signal, thereby reducing the need for additional dedicated sensing components
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
This solution effectively measures force applied to displays by transforming self-capacitance distortions into measurable force values, providing accurate force detection suitable for various devices including smartphones and industrial applications.
Implementation Method 1
an electric voltage causing a self-capacitance in the conductor relative to a diameter of the bend
Data Source
Figure 1
Figure 2a
Figure 2b
AI summary
A sensor and a method for detecting a displacement are disclosed with one implementation having a force sensor on a display. The sensor reacts to a bend of a conductor, wherein a diameter of the bends corresponds to a self-capacitance that is measurable from the conductor. In one embodiment the bent conductor is placed between two circuit boards or between a circuit board and a display, wherein a force applied to either surface causes a change in the bend diameter and the force may be measured. The sensor may be digital with a processor or analog with discrete components.