Adjustable Magnetic Closure for Foldable Device Hinge Torque

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Magnetic closure arrangements in foldable electronic devices face variability due to manufacturing tolerances, leading to inconsistent opening forces, which can result in a sub-optimal user experience, either making the device difficult to open or causing it to open unexpectedly.

Innovation Solution

The solution involves selectively adjustable metal members that allow for customizable magnetic interaction areas, enabling precise control of the magnetic opening force to balance hinge torque, ensuring the device remains closed when supported and can be opened with a single finger.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If magnetic strength is increased to accommodate manufacturing tolerances, then the device remains securely closed, but the device becomes more difficult to open

Engineering Contradiction:
Improvedevice closure stabilityVSAvoidopening force
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The patent applies parameter changes by adjusting the magnetic force strength to specific ranges (e.g., 0.5N to 2N opening force) and modifying physical parameters such as magnet size, magnet-to-metal distance, and metal member configuration to achieve optimal balance between closure stability and ease of opening

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements local quality by adding selective metal members (tabs, strips, or sheets) at specific locations within the base or cover to locally enhance magnetic interaction in areas where additional magnetic force is needed, rather than uniformly increasing magnetic strength across the entire device

Inventive Principle:
Principle #3Local quality

2Ease of operation

If magnetic strength is decreased to ease opening, then the device opens easily, but the device may open unexpectedly when closed

Engineering Contradiction:
Improveopening forceVSAvoiddevice closure stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent uses parameter changes to set the magnetic force within optimized ranges that prevent unexpected opening while maintaining ease of operation, specifically controlling the opening force to be between 0.5N and 2N through adjustments in magnet strength, distance, and metal member configuration

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The magnetic closure arrangement is designed to automatically maintain proper closure force without external intervention, where the magnetic attraction naturally balances between holding the device closed and allowing intentional opening by the user

Inventive Principle:
Principle #25Self-service

3Manufacturing precision

If binning magnets or high-torque hinges are used to control opening force, then consistent magnetic force is achieved, but system cost increases

Engineering Contradiction:
Improvemagnetic force consistencyVSAvoidsystem cost
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent achieves magnetic force consistency through parameter changes in the design stage, specifying optimal magnet sizes, distances, and metal member configurations that provide consistent performance across production batches without requiring expensive binning or specialized high-torque hinges

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses cost-effective metal members (such as metal tabs, strips, or sheets) that can be easily manufactured and integrated into the device structure, replacing more expensive solutions like binned magnets or specialized high-torque hinge mechanisms

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 approach ensures a consistent and optimal user experience by allowing the magnetic force to be adjusted to meet specific device requirements, satisfying both spine and table tests, thereby maintaining the device in a closed position when needed and allowing single-finger operation when desired.

Implementation Method 1

a magnetic closure arrangement maintains the two portions in abutting engagement when in a closed position

Methodology Applied
Scientific EffectMagnetic force: Magnetism

Implementation Method 2

The metal members are attracted to the magnets and the magnetic interaction area selectively changes to adjust a corresponding magnetic force

Methodology Applied
Scientific EffectMagnetic attraction: Magnetism

Data Source

PatentEP4022412B1Opening force control for foldable electronic devices
Publication Date: 2024.10.30 MICROSOFT TECHNOLOGY LICENSING LLC
  • EP4022412B1 patent drawingFigure 1
  • EP4022412B1 patent drawingFigure 2
  • EP4022412B1 patent drawingFigure 3

AI summary

A foldable electronic device includes a first portion, a second portion, and a hinge connecting the first portion and the second portion. The hinge is configured to allow pivoting movement of the first portion relative to the second portion, wherein the hinge has a hinge force. One or more magnets are coupled to the first portion, and a plurality of metal members are coupled to the second portion. Each metal member of the plurality of metal members is configured for individual removal from the second portion to define a magnetic force based on the hinge force, thereby allowing the first and second portions to be maintained together when in a closed orientation and allowing for easy one finger opening operation from the closed orientation.