3D Multipolar Magnet Array for Foldable Hinge Gap Reduction

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Solution Overview

Problem

In foldable electronic devices, the magnetic fields generated by magnets at the ends of separated housings reduce the area available for input devices using electromagnetic induction, such as stylus pens, due to the repulsive force forming gaps when the device is folded.

Innovation Solution

A magnet array with a designated three-dimensional multipolar configuration is used, accompanied by guide members to deviate the magnetic field direction, ensuring reduced magnetic field magnitude on the display area while maintaining gap reduction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If magnets are disposed at two opposite ends of the separated housings to reduce the gap, then the gap between housings is reduced, but the area available for input devices using electromagnetic induction is reduced

Engineering Contradiction:
Improvegap reduction forceVSAvoidarea available for input device
Core Design Contradiction:
ForceVSArea of stationary object

Solution Approach 1:

The magnet array uses magnets with different polarities arranged in a specific pattern where magnets closer to the display area have polarities that create weaker magnetic fields in that region, while magnets farther away have polarities optimized for gap reduction. This local variation in magnetic field strength allows simultaneous achievement of gap reduction and preservation of input device functionality.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention changes the parameters of the magnetic field distribution by using a multipolar arrangement instead of a simple bipolar configuration. By varying the polarity pattern and spatial distribution of magnets, the magnetic field strength is adjusted to be stronger at the edges for gap reduction and weaker in the central display area for input device compatibility.

Inventive Principle:
Principle #35Parameter changes

2Force

If a strong magnetic field is generated to reduce the gap between housings, then the gap reduction effect is improved, but the magnetic field interference with input devices increases

Engineering Contradiction:
Improvegap reduction effectVSAvoidmagnetic field interference
Core Design Contradiction:
ForceVSObject-affected harmful factors

Solution Approach 1:

Different regions of the magnet array produce different magnetic field strengths tailored to local requirements. The edge regions generate strong fields for gap reduction, while the central regions generate weaker fields to minimize interference with electromagnetic induction-based input devices.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention converts what would normally be a harmful strong magnetic field into a beneficial force by strategically directing it away from the display area using the multipolar arrangement. The strong fields are positioned to act on the housing edges for gap reduction, while the field geometry naturally directs weaker fields toward the display area, turning a potential harm into a benefit.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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 field is effectively directed away from the display area, preserving input device functionality while minimizing gaps between device sections.

Implementation Method 1

magnet array including a plurality of magnets in a three-dimensional multipolar magnetic array

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

the magnetic field generated from the magnet

Methodology Applied
Scientific EffectMagnetic force: Lorentz Force

Implementation Method 3

the electronic device may detect the magnetic field generated from the input device using electro magnetic resonance (hereinafter, referred to as EMR) scheme

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP4167049B1Electronic device comprising magnet array
Publication Date: 2026.03.18 SAMSUNG ELECTRONICS CO LTD
  • EP4167049B1 patent drawingFigure 1
  • EP4167049B1 patent drawingFigure 2
  • EP4167049B1 patent drawingFigure 3

AI summary

An electronic device according to various embodiments of the present invention comprises: a foldable housing which has a hinge structure and includes a first housing and a second housing, wherein the first housing is connected to the hinge structure and includes a first surface facing a first direction, a second surface facing a second direction opposite the first direction, and a first side surrounding at least a portion of the space between the first surface and the second surface, and the second housing is connected to the hinge structure and includes a third surface facing a third direction, a fourth surface facing a fourth direction opposite the third direction, and a second side surrounding at least a portion of the space between the third surface and the fourth surface, the first surface facing the third surface when the electronic device is in a folded state, and the third direction being the same as the first direction when the electronic device is in an unfolded state; a flexible display extending from the first surface to the third surface; and a magnet array which has a plurality of magnets in a three-dimensional multipolar magnetic arrangement, and includes a first magnet array disposed within the first housing and a second magnet array disposed within the second housing, wherein the first magnet array may correspond to the second magnet array when the electronic device is in the folded state.