Electromagnetic Induction Key Switch for Quiet Contactless Sensing

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing switch technologies face challenges in extending the wear life of contact parts, often resulting in noise and compromising user experience due to severe wear and tear.

Innovation Solution

A key design utilizing a magnetic component, closed loop, voltage drop detection chip, and conductor that cuts magnetic induction lines to generate induced current, eliminating the need for contact parts and enhancing user experience through reduced noise and improved durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional snap joints, springs and capacitances are used in keys and switches, then the device can be manufactured with existing technologies, but the wear life of contact parts is limited and noise is generated during operation

Engineering Contradiction:
Improvewear life of contact partsVSAvoidnoise during operation
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the traditional mechanical contact-based switch mechanism (snap joints, springs, capacitances) with a magnetic field-based detection system. A magnetic component generates a magnetic field, and a conductor detects changes in magnetic flux as the key moves, generating voltage signals without physical contact. This eliminates mechanical wear and operational noise while maintaining switching functionality.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces a magnetic field as an intermediary between the key movement and the detection system. Instead of direct mechanical contact, the key's movement alters the magnetic flux through a conductor, which generates voltage signals. This magnetic intermediary eliminates direct contact between moving parts, thereby extending wear life and reducing noise.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If materials and processing costs are increased to extend the wear life of contact parts, then the service life can be improved, but the manufacturing cost increases and good hand feeling is not obtained

Engineering Contradiction:
Improveservice life of contact partsVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent eliminates the need for durable contact materials by replacing the mechanical contact system with a magnetic field detection system. The key movement is detected through changes in magnetic flux that induce voltage in a conductor, requiring no wear-resistant materials or complex processing, thereby reducing manufacturing costs while extending service life.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent extracts and removes the contact parts from the switching mechanism entirely. By using magnetic field detection, the system eliminates the need for physical contact elements that would require expensive wear-resistant materials and complex processing, simplifying manufacturing while improving reliability.

Inventive Principle:
Principle #2Taking out (Extraction)

3Device complexity

If traditional contact-based switches are used, then the device structure can be simple, but the operational noise compromises user experience and the wear life is limited

Engineering Contradiction:
Improvestructure of key mechanismVSAvoidoperational noise
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent replaces the simple mechanical contact structure with a magnetic field-based detection system. While the magnetic component and conductor add some structural elements, they eliminate the need for complex wear-resistant contact mechanisms. The magnetic field detection provides noise-free operation while maintaining reasonable structural simplicity.

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 solution significantly extends the service life of the key, reduces noise, and improves hand feeling, thereby enhancing user experience by leveraging electromagnetic induction to detect key states without physical contact.

Implementation Method 1

the key body moves, the key body drives the conductor to cut magnetic induction lines in the magnetic field

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3163752B1key
Publication Date: 2019.09.25 ZTE CORP
  • EP3163752B1 patent drawingFigure 1
  • EP3163752B1 patent drawingFigure 2
  • EP3163752B1 patent drawingFigure 3

AI summary

A key is provided, including: a magnetic component arranged to generate a magnetic field; a closed loop, herein the closed loop includes a preset device in series connection and a conductor set in the magnetic field; a voltage drop detection chip, herein the voltage drop detection chip has two pins respectively connected to two ends of the preset device and an output port arranged to output a detected voltage drop signal between the two pins; and a key body movably connected on a supporting part, herein the key body is connected to the conductor, the key body can move in two opposite directions on the supporting part, and the key body drives the conductor to cut magnetic induction lines in the magnetic field during motion.