Speaker Magnetic Circuit with Opposing Inner and Outer Magnets
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Solution Overview
Problem
Existing speaker technologies face challenges in achieving a strong magnetic circuit for improved performance, particularly in miniaturized speakers like headphones, where magnetic flux density and acoustic characteristics are compromised due to magnet size and configuration limitations.
Innovation Solution
A speaker design featuring an outer magnet and an inner magnet with opposing magnetization directions, where the inner magnet is disposed within the outer magnet through a gap, forming a strong magnetic circuit. This configuration allows for a reduced magnet size while maintaining equivalent magnetic flux density, enhancing acoustic and output characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a single permanent magnet is used in conventional speaker designs, then the structure is simple, but the magnetic flux density is insufficient and the magnetic circuit is not strong enough
Solution Approach 1:
The single permanent magnet is divided into two separate permanent magnets (first and second), each with specific magnetization directions. This segmentation allows the magnetic fields to combine constructively, increasing the overall magnetic flux density in the magnetic gap while maintaining a relatively simple structure.
Solution Approach 2:
The first and second permanent magnets are positioned in a nested configuration where they work together to create a combined magnetic field. The magnets are arranged such that their magnetic fields overlap and reinforce each other in the magnetic gap, achieving stronger magnetic flux density without significantly increasing the overall speaker size.
2Volume of moving object
If the magnet size is reduced for miniaturization, then the speaker can be miniaturized, but the magnetic flux density and acoustic characteristics are compromised
Solution Approach 1:
The magnetic field distribution is optimized locally by positioning the first and second permanent magnets at specific locations with specific magnetization directions. This creates a concentrated strong magnetic field in the magnetic gap region where it is most needed, allowing for miniaturization without sacrificing magnetic flux density in the critical area.
Solution Approach 2:
The magnetic circuit uses a composite configuration combining two permanent magnets with different magnetization directions along with magnetic materials (yoke, pole pieces) to create an optimized magnetic field distribution. This composite approach allows for more efficient use of magnetic materials and achieves high magnetic flux density in a compact volume.
3Ease of manufacture
If conventional magnet configurations are used, then the manufacturing process is straightforward, but the acoustic output characteristics are limited
Solution Approach 1:
Instead of trying to increase magnet size to improve acoustic output, the invention inverts the approach by using two smaller magnets with optimized magnetization directions to create a more efficient magnetic circuit. This inverted thinking allows for improved acoustic output through better magnetic field utilization rather than simply scaling up magnet dimensions.
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 enables a stronger magnetic circuit with improved sensitivity and reduced risk of abnormal noise, allowing for miniaturization of speakers while maintaining high acoustic and output performance, and can be applied to various speaker sizes.
Implementation Method 1
the outer magnet has a ring shape and is magnetized along an axial direction of the ring shape; the inner magnet is magnetized in a direction opposite to a direction of the outer magnet along the axial direction
Implementation Method 2
a conductor portion that is a structure having a smaller electric resistance ratio than that of a magnetic body material constituting a magnetic circuit is disposed near the voice coil of a driver unit. Electromagnetic induction coupling is then generated between the voice coil and the conductor portion
Data Source
AI summary
It is an object to provide a speaker including a strong magnetic circuit and a method of manufacturing a speaker. To achieve the object, a speaker according to the present technology includes an outer magnet and an inner magnet. The outer magnet has a ring shape and is magnetized along an axial direction of the ring shape. The inner magnet has a circular outer shape when viewed from the axial direction of the outer magnet, is magnetized in a direction opposite to a direction of the outer magnet along the axial direction, and is disposed inside the outer magnet through a gap.