Ultrasonic Speaker Demodulation Structure for Variable-Gap Acoustic Output
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing speaker devices suffer from low efficiency in demodulating audible sound due to low vibration amplitude and poor acoustic performance caused by distortion of symmetrical ultrasonic waves passing through narrow gaps.
Innovation Solution
A speaker device design featuring a support structure with a sound chamber and sound hole, incorporating an ultrasonic sound emitting unit and a demodulation structure with a diaphragm and gap, where the demodulation structure vibrates in response to amplitude-modulated ultrasonic waves, altering the gap size to efficiently demodulate sound waves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If symmetrical ultrasonic waves pass through a narrow gap to demodulate audible sound, then demodulation occurs, but the vibration amplitude is low and demodulation efficiency is poor
Solution Approach 1:
The patent introduces an asymmetric resonant cavity structure with a specific cavity body and opening, replacing the conventional symmetric narrow gap. The asymmetric geometry creates stronger nonlinear acoustic effects that enhance demodulation efficiency while improving acoustic performance through resonant amplification.
Solution Approach 2:
The patent utilizes mechanical resonance by designing the demodulation structure as a resonant cavity with specific dimensional parameters. The ultrasonic waves excite resonant vibrations in the cavity, amplifying the vibration amplitude and enhancing the demodulation process through resonant coupling between the ultrasonic carrier and audible signal.
2Productivity
If the vibration amplitude of the demodulation structure is increased, then demodulation efficiency improves, but the device complexity increases
Solution Approach 1:
The patent optimizes demodulation efficiency by carefully selecting and adjusting physical parameters of the resonant cavity, including cavity length, width, opening size, and wall thickness. These parameter optimizations enable high vibration amplitude with a relatively simple cavity structure, avoiding excessive complexity while achieving superior demodulation performance.
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
Enhances sound wave demodulation efficiency and vibration amplitude, resulting in improved acoustic performance by minimizing distortion and maximizing sound pressure.
Implementation Method 1
an ultrasonic sound emitting unit located in the sound chamber and fixed on an inner peripheral side of the support body for emitting amplitude-modulated ultrasonic waves
Implementation Method 2
emitting amplitude-modulated ultrasonic waves
Implementation Method 3
a mechanical resonance frequency of the diaphragm is substantially equivalent to a carrier frequency of the amplitude-modulated ultrasonic wave
Implementation Method 4
a vibration of the diaphragm causes a geometric dimension change of the gap in at least one direction, resulting in periodic variations of acoustic impedance of the gap
Data Source
AI summary
The present invention provides a speaker device having a support structure with a support body provided with a sound chamber and an annular sound hole. The speaker device further includes an ultrasonic sound emitting unit for emitting symmetrical ultrasonic waves, and a demodulation structure with a diaphragm and multiple fixed parts. The diaphragm is spaced apart from the sound hole. The ultrasonic waves emitted by the ultrasonic sound emitting unit drive the demodulation structure to vibrate, adjusting the size of the gap. Compared with the prior art, the speaker device of the present invention has high sound wave demodulation efficiency, good improvement in vibration system amplitude, and excellent acoustic performance.