Electropermanent Magnet Key Assembly for Adjustable Tactile Feedback
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Solution Overview
Problem
Existing keyboard technologies using permanent magnets lack adjustability in the upward force required to return keys to their neutral position, limiting customization and tactile feedback for users.
Innovation Solution
The use of electropermanent magnets (EPMs) in key assemblies, which can be individually controlled to provide adjustable upward force and allow for multiple neutral positions, enabling customizable tactile sensation and reduced material usage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If permanent magnets are used in key assemblies, then the upward force to return keys to neutral position is provided, but adjustability and customization are limited
Solution Approach 1:
The patent applies the dynamics principle by transitioning from static permanent magnets to electropermanent magnets that can dynamically change their magnetic state. The EPM allows the upward force to be adjusted between different levels (including fully on, fully off, and intermediate states) by applying electrical current pulses, enabling real-time adaptability of key resistance without increasing overall system complexity
Solution Approach 2:
The patent implements parameter changes by modifying the magnetic flux density parameter of the magnet through electrical control. The electropermanent magnet can change its magnetic field strength from maximum to zero or intermediate values by applying reverse current pulses, directly enabling adjustable upward force and customizable tactile feedback for different keys
2Loss of substance
If traditional spring mechanisms are used to provide upward force, then simplicity is maintained, but material usage and weight increase
Solution Approach 1:
The patent replaces the traditional mechanical spring system with an electropermanent magnet-based magnetic field system. This substitution eliminates the need for physical springs and associated materials, reducing material usage and weight while providing precise control over the upward force through electrical signals, thereby improving both resource efficiency and operational control
Solution Approach 2:
The patent employs composite material principles by combining permanent magnet material with magnetically soft material in the EPM structure. This composite approach creates a magnet system that exhibits both permanent magnetic properties and controllable magnetic switching characteristics, enabling adjustable upward force with reduced material consumption compared to traditional mechanical systems
3Ease of operation
If electropermanent magnets are used, then granular control of key resistance is achieved, but device complexity increases
Solution Approach 1:
The patent applies periodic action by using pulsed electrical current signals to control the EPM state changes. Instead of continuous power delivery, brief current pulses are applied to switch the magnetic state of individual EPMs, enabling granular control of key resistance with minimal energy consumption and simplified control logic compared to continuous analog control systems
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
EPMs allow for granular control of key resistance, reducing material costs and weight while providing a robust tactile experience, enabling users to adjust the force and position of keys based on user preference and application needs.
Implementation Method 1
a magnet situated beneath the scissor plates. Once the user removes the downward force, the magnet may exert a magnetic force to pull the flange operably connected to the scissor plates back toward the magnet
Implementation Method 2
The use of electropermanent magnets (EPMs) in key assemblies, which can be individually controlled to provide adjustable upward force
Data Source
AI summary
An electro-permanent magnet (EPM) key assembly of an information handling system may comprise a pair of scissor plates operably connected to a base contact assembly including an EPM such that each of the pair of scissor plates may rotate away from one another in the presence of downward force on a key cap situated atop the pair of scissor plates for actuation of the EPM key assembly; the EPM comprising a low-coercivity magnet and a high-coercivity magnet; wherein an application of a first current pulse applied to an electrically conductive wire coiled around the low-coercivity magnet places the EPM in a first on state to assert a first magnetic field on a ferromagnetic flange operatively coupled to rotate with at least one scissor plate about a hinge; and wherein an application of a second current pulse applied to the electrically conductive wire places the EPM in a second on state to increase the magnetic field on the ferromagnetic flange.