Magnetic Key Switch Eliminates Rubber Fatigue

Solution Overview

Problem

Conventional key switches rely on resilient members like rubber, which can fatigue over time, reducing the switch's lifetime.

Innovation Solution

A key switch design utilizing magnetic attraction forces to move a key cap between pressed and non-pressed positions, eliminating the need for resilient members by using a support device and magnetic areas to maintain and restore the key cap's position.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a resilient member is used to support the key cap and provide elastic force, then the key cap can return to its original position after being pressed, but the resilient member will get fatigue over time and reduce the lifetime of the key switch

Engineering Contradiction:

Improvelifetime of key switchVSAvoidservice life of resilient member

Core Design Contradiction:

ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent replaces the mechanical resilient member with a magnetic field-based support system. The base includes a magnetic member that generates a magnetic field to support the key cap, eliminating the need for rubber or spring elements. This substitution of mechanical components with a magnetic field-based system resolves the fatigue issue of resilient members while maintaining the key cap's ability to return to its original position.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the physical state and properties of the support mechanism from elastic mechanical deformation to magnetic field interaction. By utilizing magnetic attraction and repulsion forces instead of elastic material deformation, the system achieves indefinite operational life without fatigue, as magnetic fields do not degrade like elastic materials.

Inventive Principle:

Principle #35Parameter changes

2Ease of operation

If a resilient member is used to enable key cap movement between pressed and non-pressed positions, then the key switch can function properly, but the resilient member is subject to wear and tear

Engineering Contradiction:

Improvekey cap movementVSAvoidwear resistance

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent replaces the mechanical resilient member with a magnetic field-based support system. The base includes a magnetic member that generates a magnetic field to support the key cap, eliminating the need for rubber or spring elements. This substitution of mechanical components with a magnetic field-based system resolves the fatigue issue of resilient members while maintaining the key cap's ability to return to its original position.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Strength

If rubber material is used for the resilient member, then the key cap can be supported and returned to position, but the rubber may get fatigue after long use

Engineering Contradiction:

Improveelastic forceVSAvoidservice life before fatigue

Core Design Contradiction:

StrengthVSDuration of action of moving object

Solution Approach 1:

The patent replaces the mechanical resilient member with a magnetic field-based support system. The base includes a magnetic member that generates a magnetic field to support the key cap, eliminating the need for rubber or spring elements. This substitution of mechanical components with a magnetic field-based system resolves the fatigue issue of resilient members while maintaining the key cap's ability to return to its original position.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs a composite approach by combining magnetic materials in the base with a non-magnetic support device, creating a hybrid system that leverages the advantages of magnetic field generation while avoiding the limitations of elastic materials. This composite structure enables the key cap to be supported and returned to position without the fatigue problems associated with rubber.

Inventive Principle:

Principle #40Composite materials

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 design extends the key switch's lifetime by avoiding the wear and tear associated with resilient members, ensuring consistent operation without the need for replacement.

Implementation Method 1

The magnetic member induces the magnetic induction member to generate magnetism, so as to form a second magnetic area on the magnetic induction member

Methodology Applied

Scientific EffectMagnetic induction: Electromagnetic Induction

Implementation Method 2

a magnetic attraction force between the first magnetic area and the second magnetic area keeps the key cap at the non-pressed position

Methodology Applied

Scientific EffectMagnetic attraction force: Magnetism

Data Source

PatentUS11049673B2Key switch

Publication Date: 2021.06.29 DARFON ELECTRONICS CORP

AI summary

A key switch includes a key cap, a base, a support device and a bracket. The base has a first magnetic area. The support device is disposed between the key cap and the base. The bracket is movably connected to the support device. The bracket has a second magnetic area corresponding to the first magnetic area. When the key cap is not pressed, a magnetic attraction force between the first and second magnetic areas keeps the key cap at a non-pressed position. When the key cap is pressed by an external force, the key cap moves with the support device from the non-pressed position to a pressed position. When the external force is released, the second magnetic area moves toward the first magnetic area due to the magnetic attraction force, such that the key cap moves with the support device from the pressed position to the non-pressed position.