Micro Speaker Capacitive Diaphragm Amplitude Detection
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Solution Overview
Problem
The existing methods for detecting the amplitude of a speaker's diaphragm, such as the linear estimation method, fail to accurately detect the real-time amplitude of a micro speaker.
Innovation Solution
A micro speaker design that includes a magnetic circuit system with a pole plate forming capacitors with a conductive dome, allowing for the detection of real-time diaphragm amplitude and unbalanced vibrations through changes in capacitor values as the diaphragm vibrates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If linear estimation method is used to detect diaphragm amplitude, then the detection method is simple, but the measurement precision is insufficient and cannot detect real-time amplitude correctly
Solution Approach 1:
The patent replaces the conventional linear estimation method (mechanical/mathematical calculation approach) with a capacitive sensing system that directly measures diaphragm position through electrical field changes. The conductive diaphragm forms a capacitor with the segmented pole plate, and changes in capacitance directly reflect real-time diaphragm amplitude without requiring complex signal processing or estimation algorithms.
Solution Approach 2:
The patent introduces an electrical field as an intermediary between the diaphragm and the detection system. By forming a capacitor with the segmented pole plate, the diaphragm's mechanical vibrations are converted into electrical signals through changes in capacitance, providing a direct and accurate measurement of real-time amplitude.
2Measurement precision
If capacitor-based detection system is implemented, then real-time amplitude detection precision is improved, but the device structure becomes more complex
Solution Approach 1:
The patent makes the pole plate serve multiple functions: it remains a core component of the magnetic circuit system for generating the magnetic field necessary for speaker operation, and simultaneously acts as one electrode of a capacitor for detecting diaphragm vibrations. This multi-functionality eliminates the need for separate detection components, reducing overall device complexity while maintaining high measurement precision.
Solution Approach 2:
The patent merges the magnetic circuit system and the capacitive sensing system by integrating the pole plate as both a magnetic component and a capacitive electrode. This combination allows the same structural element to fulfill both magnetic field generation and vibration detection functions, simplifying the overall device architecture.
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
Enables accurate real-time detection of diaphragm amplitude and unbalanced vibrations, improving the measurement precision of micro speaker performance.
Implementation Method 1
Each unit of the pole plate forms a capacitor with the conductive dome
Data Source
AI summary
A micro speaker is disclosed. The micro speaker includes a vibration system including a diaphragm and a voice coil for driving the diaphragm, the diaphragm including a conductive dome a suspension surrounding the conductive dome; a magnetic circuit system including a lower plate, a first magnetic part on the lower plate, a second magnetic part on the lower plate, a pole plate attached to the first magnetic part and including a plurality of units, one of the first and second magnetic part being a permanent magnet for forming a magnetic gap; capacitors formed by the conductive dome and the units of the pole plate for outputting electrical signals according to vibrations of the diaphragm and for detecting real-time replacement of the diaphragm.