Ingress-Tolerant Switch Assembly Using Magnetic Sensing
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Solution Overview
Problem
Portable electronic devices face challenges in maintaining ingress protection against water due to the vulnerability of moving parts in user input devices, such as buttons or switches, which can lead to water ingress despite having watertight housings.
Innovation Solution
An ingress-tolerant switch assembly is designed with components made of corrosion-resistant materials, including a button, spring, and magnet, which communicates electromagnetically with internal electronics, allowing the switch assembly to operate effectively even when not watertight, using a magnetic sensor to detect the magnet's position and generate signals for device functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If mechanical buttons or switches are used for user input, then ease of operation is improved, but water ingress protection is worsened due to vulnerability of moving parts
Solution Approach 1:
The patent replaces the traditional mechanical button press mechanism with a magnetic field-based detection system. A magnet is positioned behind the button, and a magnetic sensor detects the magnet's position to determine button press events. This eliminates mechanical contact points and moving parts that could compromise water ingress protection, while preserving the user-friendly button interface.
2Reliability
If watertight housing is implemented, then ingress protection is improved, but device complexity increases due to additional sealing requirements
Solution Approach 1:
By substituting mechanical button mechanisms with magnetic field sensing, the patent eliminates the need for complex sealed button assemblies and moving parts within the housing. The magnetic sensor and magnet can be positioned outside the sealed enclosure, simplifying the watertight design while maintaining input functionality.
3Ease of operation
If magnetic sensor is used inside enclosure, then ease of operation is maintained, but object-generated harmful factors worsen due to magnetic field interference with electronics
Solution Approach 1:
The patent introduces a magnetic field as an intermediary between the button interface and the internal electronics. The magnet responds to button presses and transmits this information to the magnetic sensor without requiring direct mechanical or electrical connection. This intermediary approach maintains button functionality while isolating the ingress-protected enclosure from mechanical 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
The solution ensures that the electronic device remains functional and protected from water ingress, as the switch assembly expels any fluid that enters the recessed portion, maintaining the device's operational integrity while avoiding the need for mechanical or electrical interfaces within the housing.
Implementation Method 1
A spring force of the spring is overcome by a pressing force applied by a user to the button such that the spring moves the magnet into proximity of the magnetic sensor to cause the magnetic sensor to generate a sensor signal
Data Source
Figure 1
Figure 2~4
AI summary
This disclosure relates to ingress-tolerant input devices. Aspects of the disclosure relate to an ingress-tolerant switch assembly 100 for operating an electronic device 10 in an ingress-protected manner. The switch assembly includes a button 115 configured to be coupled to an outer surface 30 of an enclosure 20 of the electronic device 10. The switch assembly also includes a spring 120 operably coupled to the button 115 and a magnet 130 coupled to the spring 120. A pressing force applied by a user to the button 115 overcomes a spring force of the spring 120 to move the magnet 130 into proximity of a magnetic sensor 50 to cause the magnetic sensor to generate a sensor signal for performing a function of the electronic device.