Piezoelectric Speaker Flexible Weight Frequency Response
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Solution Overview
Problem
Piezoelectric speakers suffer from unstable output and sound distortion due to peak-dip phenomena in their frequency response characteristic, which degrades sound quality and makes them unsuitable for thin, portable devices.
Innovation Solution
A piezoelectric speaker design that incorporates a weight made of flexible material on or below the acoustic diaphragm to control resonant mode amplitude, thereby enhancing the frequency response characteristic and improving sound quality by adding mass and widening the frequency band.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If a piezoelectric speaker uses resonance of a piezoelectric thin film itself to drive the diaphragm, then the speaker becomes thin and lightweight, but peak-dip phenomena occur in the frequency response characteristic causing unstable output and sound distortion
Solution Approach 1:
The patent changes the physical parameters of the diaphragm by adding a weight layer with specific mass (0.1-10% of total diaphragm mass) and adjusting its position (distance of 0.1-10mm from diaphragm surface). This parameter modification shifts the resonant frequency and dampens peak-dip phenomena, stabilizing the frequency response while preserving the thin-profile design of the piezoelectric speaker.
2Reliability
If conventional methods bond piezoelectric devices with different resonant frequencies on both surfaces of the diaphragm or increase the mass of the piezoelectric body, then the resonant frequency is lowered to adjust amplitude, but this generally enhances peak-dip in the lower register and does not achieve uniform sound quality
Solution Approach 1:
The patent introduces a weight layer as an intermediary element between the piezoelectric actuator and the diaphragm. This intermediate mass modifies the vibrational characteristics by adding inertial loading, which dampens resonant peaks and fills frequency dips. The weight layer acts as a mediator that smooths the frequency response without requiring complex multi-device configurations, achieving uniform sound quality across the frequency spectrum.
3Weight of moving object
If the mass of the piezoelectric body is increased by disposing a vibration adjusting portion at the center, then the resonant frequency decreases, but this approach does not sufficiently enhance overall sound quality and may increase device complexity
Solution Approach 1:
The patent segments the mass addition function from the piezoelectric body itself and places it as a separate weight layer on or near the diaphragm. This segmentation allows independent optimization: the piezoelectric body remains lightweight and simple, while the separate weight layer provides the necessary mass for frequency adjustment. The modular approach reduces manufacturing complexity compared to integrating vibration-adjusting portions directly into the piezoelectric structure.
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 addition of a flexible weight above or below the acoustic diaphragm reduces initial resonant frequency, stabilizes output, and enhances sound flatness, significantly improving the frequency response characteristic and overall sound quality.
Implementation Method 1
a piezoelectric device having at least one piezoelectric layer and an electrode formed on or on and below the piezoelectric layer to apply an electrical signal to the piezoelectric layer
Implementation Method 2
disposing a weight of a flexible material on an acoustic diaphragm or on and below an acoustic diaphragm to thereby control a vibration
Implementation Method 3
a weight disposed above the acoustic diaphragm or above and below the acoustic diaphragm on which the piezoelectric device is disposed to thereby control a vibration
Data Source
AI summary
The present disclosure relates to a piezoelectric speaker having a weight that enables a frequency response characteristic of the piezoelectric speaker to be uniform by disposing a weight of a flexible material on an acoustic diaphragm or on and below an acoustic diaphragm of the piezoelectric speaker, thereby enhancing flatness of sound. The piezoelectric speaker having the weight includes a piezoelectric device having a piezoelectric layer and an electrode formed on or on and below the piezoelectric layer to apply an electrical signal to the piezoelectric layer; an acoustic diaphragm having a wider area than the piezoelectric device and bonded on one surface of the piezoelectric device; a frame disposed in a form that surrounds a side surface of the acoustic diaphragm; and a weight disposed above the acoustic diaphragm or above and below the acoustic diaphragm on which the piezoelectric device is disposed to thereby control a vibration.