Flat Speaker Diaphragm Vibration Damping via Segmented Support

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Solution Overview

Problem

Existing flat speakers face challenges in suppressing vibrations at the outer circumference of the diaphragm, leading to interference and reduced acoustic characteristics due to insufficient cancellation of transmitted and reflected vibrations, which results in divided resonance.

Innovation Solution

The implementation of a flat speaker design that includes a diaphragm with a flat plate shape, a drive unit attached to its back surface, a fixing member that secures the diaphragm's outer circumference, and support members with varying hardness and internal loss values to absorb and cancel out vibrations, along with a heat insulating member to prevent heat transfer and maintain acoustic quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If a fixing member is used to secure the diaphragm outer circumference, then the diaphragm is fixed in position, but vibrations at the outer circumference are not sufficiently suppressed leading to divided resonance

Engineering Contradiction:
Improvediaphragm positioning stabilityVSAvoiddivided resonance
Core Design Contradiction:
Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

The support structure is segmented into multiple support members arranged along the radial direction, with each member having different hardness values. This segmentation allows different portions of the diaphragm outer circumference to be supported with different damping characteristics, effectively suppressing vibrations and preventing divided resonance while maintaining positional stability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different support members are assigned different hardness values based on their positions along the radial direction. This local quality differentiation optimizes vibration suppression at different locations, where softer support members provide better damping for regions prone to resonance while harder support members maintain structural integrity and positioning stability.

Inventive Principle:
Principle #3Local quality

2Object-generated harmful factors

If support members with varying hardness are introduced to suppress vibrations, then acoustic characteristics are improved, but device complexity increases

Engineering Contradiction:
Improvevibration suppressionVSAvoidsupport member configuration
Core Design Contradiction:
Object-generated harmful factorsVSDevice complexity

Solution Approach 1:

The support members are designed with varying hardness values to create a dynamic damping effect that adapts to different vibration frequencies and amplitudes. This dynamic characteristic allows the support structure to effectively suppress vibrations across a broad frequency range while maintaining a relatively simple overall configuration.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The hardness parameter of support members is systematically varied along the radial direction to optimize vibration suppression performance. By changing this physical parameter in a controlled manner, the patent achieves effective damping without requiring complex multi-component structures, thus improving acoustic characteristics while limiting complexity increase.

Inventive Principle:
Principle #35Parameter changes

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 configuration effectively absorbs and cancels out vibrations, suppresses resonance, and enhances acoustic characteristics by improving frequency response and reducing heat transfer to the diaphragm, resulting in improved sound emission and speaker performance.

Implementation Method 1

support members with varying hardness and internal loss values to absorb and cancel out vibrations

Methodology Applied
Scientific EffectVibration damping: Damping

Implementation Method 2

support members with varying hardness and internal loss values to absorb and cancel out vibrations

Methodology Applied
Scientific EffectInternal loss: Hysteresis

Implementation Method 3

heat insulating member to prevent heat transfer and maintain acoustic quality

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Data Source

PatentEP3528510B1Flat speaker and display device
Publication Date: 2022.02.09 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3528510B1 patent drawingFigure 1
  • EP3528510B1 patent drawingFigure 2
  • EP3528510B1 patent drawingFigure 3

AI summary

A flat speaker is provided that is capable of improving acoustic characteristics. The flat speaker includes a diaphragm having a flat plate shape, a drive unit that is attached to a back surface of the diaphragm and vibrates the diaphragm, a fixing member that fixes an outer circumference of the diaphragm in a circumferential direction, a first support member that is disposed on an inner side in a radial direction of the fixing member, supports the back surface of the diaphragm in the circumferential direction, and has a value of hardness smaller than a value of hardness of the fixing member and/or a value of internal loss larger than a value of internal loss of the fixing member, and a second support member that is disposed on an inner side in the radial direction of the first support member, supports the back surface of the diaphragm in the circumferential direction, and has a value of hardness smaller than the value of hardness of the first support member and/or a value of internal loss larger than the value of internal loss of the first support member.