Magnetic Attraction Key Switch Structure for Thin Keyboard Design

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Solution Overview

Problem

Conventional keyswitch structures relying on elastic members like rubber domes face challenges in miniaturization for thin keyboards, as they compromise tactile feedback and structural stability, and have limited service life due to deformation-based return forces.

Innovation Solution

A keyswitch structure utilizing magnetic attraction forces between frames to provide return force, eliminating the need for elastic members and enhancing tactile feedback while increasing service life by avoiding deformation-based mechanisms.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If an elastic member (rubber dome) is used to provide return force for the keycap, then the keycap can return to its original position, but the size of the elastic member cannot be reduced without losing tactile feedback and action stability

Engineering Contradiction:

Improvesize of elastic memberVSAvoidtactile feedback and action stability

Core Design Contradiction:

Volume of moving objectVSReliability

Solution Approach 1:

The patent replaces the elastic member (rubber dome) with a magnetic field interaction system. Magnets are positioned on the keycap and the base, creating magnetic attraction force that provides the return force when the keycap is released. This substitution eliminates the need for a large-volume elastic member while maintaining tactile feedback and action stability through magnetic field forces.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the physical mechanism from elastic deformation to magnetic field interaction. By adjusting magnetic field strength, magnet positions, and keycap mass, the return force characteristics can be optimized to provide adequate tactile feedback in a compact design, resolving the contradiction between size reduction and performance maintenance.

Inventive Principle:

Principle #35Parameter changes

2Force

If an elastic member with relatively large volume is used to provide return force, then sufficient tactile feedback can be achieved, but the structural strength and stability of other members (such as lift mechanism) are affected

Engineering Contradiction:

Improvereturn force magnitudeVSAvoidstructural strength and stability

Core Design Contradiction:

ForceVSStrength

Solution Approach 1:

The patent replaces the elastic member with a magnetic field-based return force mechanism. Magnets are strategically positioned on the keycap and base structure, creating magnetic attraction that provides the necessary return force without requiring a large-volume elastic component. This eliminates the conflict between return force magnitude and structural strength, as the magnetic field can be optimized independently of the mechanical structure.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Duration of action of moving object

If the keyswitch structure uses shape deformation of elastic member to provide return force, then the keycap can move upward, but the service life depends on the deformation durability of the elastic member

Engineering Contradiction:

Improveservice lifeVSAvoiddeformation durability

Core Design Contradiction:

Duration of action of moving objectVSReliability

Solution Approach 1:

The patent replaces the elastic member's shape deformation mechanism with magnetic field interaction. The magnets on the keycap and base create magnetic attraction force that acts as the return force when the keycap is released. This eliminates the wear and deformation issues associated with elastic members, significantly extending the service life of the keyswitch structure while maintaining reliable operation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 magnetic attraction-based keyswitch structure achieves sufficient tactile feedback and stability suitable for thin keyboards, with a longer service life and reduced impact on structural strength, enabling effective miniaturization without compromising action stability.

Implementation Method 1

The second magnetic portion and the first magnetic portion produce a magnetic attraction force therebetween

Methodology Applied

Scientific EffectMagnetic attraction force: Magnetism

Data Source

PatentUS9984840B2Keyswitch structure, switch structure and method of assembling a keyswitch structure

Publication Date: 2018.05.29 DARFON ELECTRONICS (SUZHOU) CO LTD

AI summary

A keyswitch structure includes a base, a keycap, a frame disposed between the base and the keycap for providing a supporting and moving mechanism to the keycap, and another frame interacting with the former frame through a magnetic attraction force. When the keycap is not pressed, the magnetic attraction force drives the two frames to stably stand on the base and form a stable supporting structure, so that the keycap is located at a farther position relative to the base. When the keycap is pressed with an external force to move toward the base, the magnetic attraction force is overcome so that the two frames depart from each other; that is, the above stable supporting structure is temporarily destroyed. Once the external force applied to the keycap is eliminated, the two frames will form the stable supporting structure again due to the magnetic attraction force.