Speaker Damper Stop Structure for Large-Amplitude Diaphragm Protection

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Solution Overview

Problem

Existing acoustic devices face challenges in preventing damage to the diaphragm and deterioration of acoustic characteristics when the diaphragm moves with a large amplitude due to excessive input to the voice coil.

Innovation Solution

An acoustic device with a damper regulation unit positioned behind the damper to control the movement of the vibrating body, preventing collisions that could cause damage by ensuring the damper collides with the regulation unit before the diaphragm or other components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a buffer member is provided near the yoke or on the diaphragm to prevent damage during large amplitude movement, then the diaphragm is protected from collision damage, but collision still occurs and damage cannot be completely prevented

Engineering Contradiction:
Improvediaphragm protectionVSAvoidcollision damage
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The damper regulation unit is positioned in advance on the rear surface of the damper at a location facing the damper, creating a preliminary stop that prevents the diaphragm from reaching the yoke. This preliminary action stops the diaphragm's excessive rearward movement before collision can occur, rather than relying on buffer members that only mitigate damage after collision has already happened.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The damper regulation unit acts as a beforehand cushioning mechanism by providing a controlled stopping point for the damper's rearward movement. This prevents the chain reaction that would lead to diaphragm-yoke collision, cushioning the system's movement in advance rather than reacting to damage after it occurs.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Power

If the diaphragm is allowed to move with large amplitude, then the acoustic output is maintained, but damage to the diaphragm and deterioration of acoustic characteristics may occur

Engineering Contradiction:
Improveacoustic outputVSAvoidacoustic characteristics
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The damper regulation unit provides mechanical feedback by physically limiting the damper's rearward movement. When the diaphragm attempts to move with excessive amplitude, the damper regulation unit engages to prevent further movement, creating a feedback mechanism that maintains acoustic output within safe limits while preventing damage and deterioration of acoustic characteristics.

Inventive Principle:
Principle #23Feedback

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

Prevents damage to the diaphragm and maintains acoustic characteristics by regulating excessive movement of the vibrating body, thereby avoiding collisions and ensuring smooth operation.

Implementation Method 1

a coil (7) located inside of a magnetic gap (G) of the magnetic circuit unit (3)

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Implementation Method 2

a damper (6) configured to connect the main body case (2) to the bobbin (5)

Methodology Applied
Scientific EffectFriction damping: Friction

Data Source

PatentEP4021014B1Acoustic device
Publication Date: 2026.04.22 ALPS ALPINE CO LTD
  • EP4021014B1 patent drawingFigure 1
  • EP4021014B1 patent drawingFigure 2
  • EP4021014B1 patent drawingFigure 3

AI summary

An acoustic device includes a main body case, a vibrating body provided inside of the main body case, a magnetic circuit unit disposed in front of the vibrating body in a sound emitting direction of the vibrating body, a coil located inside of a magnetic gap of the magnetic circuit unit, a bobbin configured to support the coil and vibrate along with the vibrating body, and a damper configured to connect the main body case to the bobbin. The damper is disposed in the rear of the vibrating body, and a damper regulation unit is provided in the rear of the damper at a position facing the damper.