Acoustic Generator Damper Placement for Frequency Response Smoothing

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Solution Overview

Problem

Conventional acoustic generators experience peaks and dips in sound pressure frequency characteristics due to resonance, making it difficult to achieve high-quality sound.

Innovation Solution

An acoustic generator with an exciter mounted on a vibrating body, featuring pairs of adjacent portions with different stiffness and a damper contacting both portions to reduce resonance and smooth sound pressure frequency characteristics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If resonance of the vibrating plate is actively utilized, then sound pressure output is improved, but frequency characteristics show peaks and dips making sound quality poor

Engineering Contradiction:

Improvesound pressure outputVSAvoidsound quality uniformity

Core Design Contradiction:

PowerVSEase of manufacture

Solution Approach 1:

The patent applies the principle of converting harm into benefit by utilizing the resonance phenomenon that causes peaks and dips in frequency characteristics. Instead of simply suppressing resonance, the invention strategically positions dampers at specific locations where resonance occurs to transform the harmful resonant vibrations into beneficial damping effects, thereby flattening frequency response while maintaining adequate sound pressure output.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent introduces a damper as an intermediary element between the vibrating plate and the surrounding structure. This damper acts as a mediator that absorbs excess vibrational energy at resonant frequencies, preventing the harmful peaks and dips in frequency characteristics while allowing the vibrating plate to maintain its resonant operation for adequate sound pressure generation.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Stress or pressure

If resonance is utilized to generate sound, then sound pressure is increased, but frequency response becomes uneven with peaks and dips

Engineering Contradiction:

Improvesound pressureVSAvoidfrequency response uniformity

Core Design Contradiction:

Stress or pressureVSStability of the object's composition

Solution Approach 1:

The patent applies local quality by positioning dampers at specific localized regions on the vibrating plate where resonance peaks occur. Rather than uniformly distributing damping throughout the entire plate, the invention identifies and targets specific local areas with high resonant energy, placing dampers only where needed to flatten frequency response while preserving sound pressure generation capabilities in other regions.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent utilizes parameter changes by adjusting the mass and stiffness parameters of the vibrating plate system through strategic damper placement. By changing the effective mass distribution and stiffness characteristics at resonant frequencies, the invention modifies the system's natural frequency response to reduce peaks and dips while maintaining adequate sound pressure output through appropriate parameter selection.

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

The solution effectively reduces peaks and dips in sound pressure frequency characteristics, resulting in improved sound quality with smoother frequency variations.

Implementation Method 1

an exciter 5 that receives an input of an electrical signal and is caused to vibrate

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Implementation Method 2

at least one damper 8 provided contacting with both of the two adjacent portions

Methodology Applied

Scientific EffectDamping: Damping

Data Source

PatentUS9392372B2Acoustic generator, acoustic generation device, and electronic device

Publication Date: 2016.07.12 KYOCERA CORP

AI summary

An acoustic generator according to an aspect of an embodiment includes a piezoelectric element (exciter), a vibrating body. The piezoelectric element receives an input of an electrical signal and is caused to vibrate. The piezoelectric element is mounted on the vibrating body, and the vibrating body is caused to vibrate by the vibration of the piezoelectric element. The acoustic generator includes at least one pair of two adjacent portions with different stiffnesses in a plan view, and has at least one damper provided contacting with both of the two adjacent portions.