Halbach Mirror Module Assembly Without Adhesive Magnet Bonding

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Solution Overview

Problem

The use of adhesive resin to bond multiple magnets in a Halbach array for an optical module leads to potential separation and increased workload and costs, affecting reliability.

Innovation Solution

An optical module design with a magnet portion having a Halbach structure, supported by a package with a bottom wall, side wall, and restriction portion, which restricts movement of magnets without adhesive resin, ensuring they remain integrated and efficient magnetic force utilization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If adhesive resin is used to bond multiple magnets in a Halbach array, then the magnets can be assembled together, but the bonding interface may peel off and magnets may separate, reducing reliability

Engineering Contradiction:
Improveease of magnet assemblyVSAvoidreliability of magnet bonding
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent replaces the chemical bonding system (adhesive resin) with a mechanical constraint system (package structure with positioning protrusions and recesses). The package includes a body with a magnet accommodating cavity and positioning protrusions that mechanically constrain the magnets, eliminating the need for adhesive resin and thereby preventing bonding interface peeling and magnet separation.

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

2Ease of manufacture

If adhesive resin is used to bond multiple magnets, then the magnets can be fixed together, but the workload and manufacturing costs increase

Engineering Contradiction:
Improveease of magnet fixationVSAvoidcomplexity of bonding process
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent merges the magnet fixation function into the package structure itself. The positioning protrusions and recesses are integrated features of the package body, combining the packaging and magnet assembly functions into a single component. This eliminates the need for separate adhesive application processes and reduces manufacturing complexity.

Inventive Principle:
Principle #5Merging (Combining)

3Use of energy by moving object

If magnets are closely positioned to the movable mirror portion, then magnetic force utilization is improved, but the magnets may move or separate without proper constraints

Engineering Contradiction:
Improvemagnetic force utilization efficiencyVSAvoidstability of magnet position
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The patent implements preliminary action by pre-positioning the magnets within the package cavity using positioning protrusions and recesses before the actual operation. The magnets are constrained in advance to prevent any movement or separation, ensuring both close positioning for efficient magnetic force utilization and stable position throughout operation.

Inventive Principle:
Principle #10Preliminary action

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

Improves reliability and reduces costs by maintaining magnet integrity and optimizing magnetic force utilization, while allowing precise positioning and efficient coil placement.

Implementation Method 1

a magnet portion (50) having an upper surface (50a), a bottom surface (50b), and a side surface (50s) extending from the upper surface to the bottom surface, and configured to generate a magnetic field acting on the movable mirror portion (10)

Methodology Applied
Scientific EffectMagnetic field generation: Magnetic Field

Implementation Method 2

The magnet portion (50) has a Halbach structure including a first magnet (51) and a pair of second magnets (52, 53)

Methodology Applied
Scientific EffectHalbach array magnetic field configuration: Halbach Array

Data Source

PatentEP4235709B1Optical module and method for manufacturing optical module
Publication Date: 2025.10.15 HAMAMATSU PHOTONICS KK
  • EP4235709B1 patent drawingFigure 1
  • EP4235709B1 patent drawingFigure 2
  • EP4235709B1 patent drawingFigure 3

AI summary

An optical module includes a mirror unit having a movable mirror portion, a magnet portion configured to generate a magnetic field acting on the movable mirror portion, and a package accommodating the magnet portion. The magnet portion has a Halbach structure including a first magnet applied with a force in a first direction, and a second magnet applied with a force in a second direction. The package has a bottom walls portion, a side wall portion, and a restriction portion configured to restrict movement of the second magnet in the second direction. The movable mirror portion is disposed in a space formed by the restriction portion.