Electropermanent Magnet Key Switch Calibration

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Solution Overview

Problem

Existing keyboard technologies using permanent magnets lack adjustability in key actuation force, limiting user customization and tactile feedback, and are prone to mechanical degradation over time.

Innovation Solution

Employing electropermanent magnets (EPMs) with a magnetic field sensor and control system that allows for adjustable key actuation force, enabling individual key customization and compensation for manufacturing defects or degradation, using a calibration module to adjust the magnetic field strength via current pulses and voltage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If permanent magnets are used in key switch assembly, then the structure is simple and reliable, but the key actuation force cannot be adjusted and degrades over time

Engineering Contradiction:

Improvekey actuation force consistencyVSAvoidadjustability of key actuation force

Core Design Contradiction:

ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent applies electropermanent magnets instead of permanent magnets, enabling the magnetic field strength to be dynamically adjusted through electrical control. This allows the key actuation force to be customized and adapted to different user preferences while maintaining the structural simplicity of permanent magnet systems.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent changes the magnetic field parameter of the electropermanent magnet through electrical current control, allowing adjustment of the key actuation force. This enables the system to adapt to different requirements while maintaining reliability, as the electrical parameters can be modified without changing the physical structure.

Inventive Principle:

Principle #35Parameter changes

2Adaptability or versatility

If electropermanent magnets with sensors and control systems are used, then adjustability and customization are improved, but device complexity increases

Engineering Contradiction:

Improvecustomization of key actuation forceVSAvoidcomplexity of magnetic field control system

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent incorporates magnetic field sensors that provide feedback to the control system, enabling automatic calibration and compensation for manufacturing variations. This feedback mechanism allows the system to achieve high precision and consistency without requiring overly complex manual adjustment mechanisms.

Inventive Principle:

Principle #23Feedback

Solution Approach 2:

The calibration module automatically calibrates each electropermanent magnet during assembly or initialization, eliminating the need for manual adjustment of each key. This self-calibrating capability reduces operational complexity while maintaining high adaptability and customization potential.

Inventive Principle:

Principle #25Self-service

3Reliability

If calibration module is added to adjust magnetic field strength, then manufacturing defects and degradation are compensated, but device complexity and manufacturing cost increase

Engineering Contradiction:

Improvecompensation for manufacturing defectsVSAvoidmanufacturing process complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The calibration module performs preliminary calibration of each electropermanent magnet during the manufacturing or assembly process. This preliminary action compensates for manufacturing defects and variations before the product reaches the user, ensuring consistent performance without requiring complex post-manufacturing adjustments.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system automatically calibrates itself through the calibration module, which measures and adjusts each electropermanent magnet's magnetic field strength without requiring manual intervention. This self-calibrating process simplifies manufacturing by eliminating the need for skilled manual adjustment while ensuring high reliability and defect compensation.

Inventive Principle:

Principle #25Self-service

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

Provides a customizable and consistent tactile experience across keys, reducing material usage and weight while maintaining robustness and adjustability, ensuring optimal key actuation force regardless of mechanical changes or defects.

Implementation Method 1

the magnet may exert a magnetic force to pull the flange operably connected to the scissor plates back toward the magnet

Methodology Applied

Scientific EffectMagnetic force: Magnetism

Implementation Method 2

supply a consistent upward force the user must overcome in order to depress the key cap

Methodology Applied

Scientific EffectMagnetic force: Magnetism

Data Source

PatentUS10797699B1System and method for calibrating an electro-permanent magnet key switch assembly

Publication Date: 2020.10.06 DELL PROD LP

AI summary

An electro-permanent magnet (EPM) key assembly of an information handling system may include an electro-permanent magnet (EPM) that may include a low-coercivity magnet and a high-coercivity magnet and a magnetic field sensor to detect the magnitude of the magnetic field of the EPM; and a calibration module to calibrate the magnitude of the magnetic field of the EPM by receiving a sensed magnitude value of the magnetic field of the EPM and adjusting the magnitude value of the magnetic field of the EPM when that magnitude value deviates from an established value by a threshold amount.