Force Sensing Device Using Inductor Elements for Noise Reduction
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Solution Overview
Problem
Conventional mechanical switches require significant space, are prone to electric shock, and struggle with dust-proofing and waterproofing, while also experiencing noise interference from external factors, making them unsuitable for modern wearable devices with sleek designs.
Innovation Solution
A force sensing device with two conductive force members and inductor elements, where the application of force changes the inductance, generating distinct resonance frequencies for accurate force detection, and a support member ensures opposite movement of the force members, allowing for precise force position detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical switch is used for force sensing, then the switch function can be implemented, but the device size and space requirement increase significantly
Solution Approach 1:
The patent replaces the mechanical switch structure with an electromagnetic sensing system consisting of a movable coil and fixed coil that generate electromagnetic forces. This substitution eliminates the need for traditional mechanical components while achieving the same force sensing and switching functionality, thereby reducing device space requirements
Solution Approach 2:
The patent utilizes changes in electromagnetic parameters (inductance, electromagnetic force) in response to applied force to detect and sense the force. By monitoring parameter changes rather than mechanical position, the system achieves force sensing with minimal physical space
2Reliability
If a mechanical switch with direct electrical contact is used, then switching function is achieved, but the risk of electric shock increases
Solution Approach 1:
The patent replaces direct mechanical and electrical contact with an electromagnetic field-based sensing system. The movable coil and fixed coil interact through electromagnetic forces without direct contact, eliminating the pathway for electric shock while maintaining switching functionality
Solution Approach 2:
The patent introduces electromagnetic fields as an intermediary between the force application and the switching action. The electromagnetic field mediates the interaction between the movable coil and fixed coil, allowing force sensing and switching without direct electrical contact between components
3Reliability
If a mechanical switch structure is used, then switching capability is provided, but dust-proofing and waterproofing become difficult to implement
Solution Approach 1:
The patent replaces the mechanical switch structure with an electromagnetic sensing system that has no moving mechanical parts requiring seals or enclosures. This eliminates the complexity of making mechanical switches dust-proof and waterproof, as the electromagnetic components can be hermetically sealed or integrated into the device housing
4Reliability
If conventional switch devices are used, then basic switching function is achieved, but noise or interference from external environmental factors occurs
Solution Approach 1:
The patent employs feedback mechanisms where the system continuously monitors the electromagnetic parameters and adjusts to compensate for external disturbances. The differential measurement approach compares signals from multiple coils to identify and reject common-mode noise, improving signal quality and reducing interference
Solution Approach 2:
The patent uses vibration-based electromagnetic actuation and sensing, where controlled vibrations of the movable coil enable precise force detection. The vibrational approach allows for high-frequency signaling that can be differentiated from low-frequency environmental noise
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 solution enables accurate force sensing with reduced noise interference and improved design integration, addressing the space and safety issues of conventional switches by providing a compact and reliable force detection mechanism.
Implementation Method 1
a first inductor element disposed on a first surface of the substrate and spaced apart from the first force member, the first inductor element having a first inductance, which is variable at a time of force input pressing the first force member
Data Source
AI summary
A force sensing device includes: a substrate disposed inside a housing and spaced apart from inner side surfaces of a first force member and a second force member; a first inductor element mounted on a first surface of the substrate and spaced apart from the first force member, the first inductor element having a first inductance, variable at a time of force input pressing the first force member; a second inductor element mounted on the first surface of the substrate and spaced apart from the second force member, the second inductor element having a second inductance, variable at a time of force input; and a support member having one end contacting the first surface of the substrate between the first inductor element and the second inductor element and another end contacting an inner side surface of the housing between the first force member and the second force member.