Dual-Direction Magnet Actuator for Audio and Haptic Resonance

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Solution Overview

Problem

Existing magnet actuators face challenges in manufacturing due to dimensional tolerance variations and limited resonance frequency ranges, making them costly and inefficient for producing both audio and haptic feedback, which require different frequency ranges.

Innovation Solution

A magnet actuator design featuring a first and second housing arrangement with balancing magnets and coils, maintaining force equilibrium and generating alternating magnetic forces to allow for displacement and broader resonance frequency ranges, enabling simultaneous production of audio and haptic feedback.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If magnets are arranged in force equilibrium with resilient support elements, then the magnet actuator can generate sound waves, but dimensional tolerance variations and force variations cause defects that are only detectable after assembly, increasing repair time and cost

Engineering Contradiction:
Improveforce equilibrium stabilityVSAvoidassembly defect detection
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by pre-assembling and balancing the magnets with resilient support elements in a force equilibrium state before final device assembly. This allows dimensional tolerance variations and force variations to be compensated in advance, ensuring that the magnet actuator is already balanced when integrated into the electronic device, thereby eliminating post-assembly defects and reducing repair requirements

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent employs parameter changes by adjusting the properties of resilient support elements to compensate for dimensional tolerance variations in magnets and housing. By modifying the resilience parameters of the support elements, the system achieves force equilibrium despite variations in component dimensions, ensuring reliable operation without requiring post-assembly adjustments

Inventive Principle:
Principle #35Parameter changes

2Device complexity

If a single magnet actuator is used, then the device structure is simplified, but the resonance frequency range is too limited to produce both audio (1000 Hz) and haptic feedback (100-200 Hz)

Engineering Contradiction:
Improvemagnet actuator structureVSAvoidresonance frequency range
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent applies universality by designing a single magnet actuator structure that can operate across multiple resonance frequency ranges. By using a main magnet interacting with multiple balancing magnets (first and second balancing magnets) that can be independently controlled through separate coils, the system achieves both audio frequency (1000 Hz) and haptic feedback frequency (100-200 Hz) operation within one integrated device, eliminating the need for separate actuators

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If multiple magnet actuators are used to cover broad resonance frequency range, then both audio and haptic feedback can be produced, but the device complexity and manufacturing cost increase

Engineering Contradiction:
Improveresonance frequency rangeVSAvoidnumber of magnet actuators
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies merging by combining multiple magnet interaction pairs into a single integrated magnet actuator structure. The main magnet interacts with both first and second balancing magnets through shared housing and resilient support elements, allowing the system to achieve broad resonance frequency coverage (both audio and haptic feedback) through one unified structure rather than requiring separate actuators, thereby reducing device complexity and manufacturing cost

Inventive Principle:
Principle #5Merging (Combining)

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 allows for a compact, cost-effective magnet actuator that maintains force balance during manufacturing, reduces defects, and generates resonance frequencies suitable for both audio and haptic feedback, simplifying production and repair.

Implementation Method 1

the first coil and the main magnet being configured to generate a first alternating magnetic force therebetween, the second coil and the main magnet being configured to generate a second alternating magnetic force therebetween

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

the first balancing magnet and the main magnet being configured to generate a first constant repulsive force therebetween, counteracting the first constant attractive force

Methodology Applied
Scientific EffectMagnetic repulsion: Magnetism

Data Source

PatentEP3906569B1Dual direction magnet actuator
Publication Date: 2024.07.31 HUAWEI TECH CO LTD
  • EP3906569B1 patent drawingFigure 1a~1b
  • EP3906569B1 patent drawingFigure 2
  • EP3906569B1 patent drawingFigure 3a~3b

AI summary

A magnet actuator (1) comprising a first housing arrangement (2) comprising a first housing (2a), a first balancing magnet (2b), and a first coil (2c) partially surrounding the first balancing magnet (2b), a second housing arrangement (3) comprising a second housing (3a), a second balancing magnet (3b), and a second coil (3c) partially surrounding the second balancing magnet (3b), and a main magnet (4) arranged between the first balancing magnet (2b) and the second balancing magnet (3b). A first constant attractive force (FC1) is generated between the first housing (2a) and the main magnet (4), the first balancing magnet (2b) and the main magnet (4) being configured to generate a first constant repulsive force (FC2) counteracting the first constant attractive force (FC1), such that the first housing arrangement (2) and the main magnet (4) are maintained in a force equilibrium state. A second constant attractive force (FC3) is generated between the second housing (3a) and the main magnet (4), the second balancing magnet (3b) and the main magnet (4) being configured to generate a second constant repulsive force (FC4) counteracting the second constant attractive force (FC3), such that the second housing arrangement (3) and the main magnet (4) are maintained in a force equilibrium state. The first coil (2c) and the main magnet (4) are configured to generate a first alternating magnetic force (FA1), and the second coil (3c) and the main magnet (4) are configured to generate a second alternating magnetic force (FA2). Manipulating electrical current in the first coil (2c) causes a change in the first alternating magnetic force (FA1) thereby causing displacement of the first housing arrangement (2) in relation to the main magnet (4), and/or manipulating electrical current in the second coil (3c) causes a change in the second alternating magnetic force (FA2) thereby causing displacement of the second housing arrangement (3) in relation to the main magnet (4). By using one magnet to operate two moving magnets, the magnet actuator is made compact while being able to generate resonance frequencies within two different ranges simultaneously.