Air-Pulse Device With Zigzag Slit for Acoustic Impedance Reduction
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Solution Overview
Problem
Conventional speaker designs face challenges in covering the entire audio frequency band from 20 Hz to 20 KHz with high fidelity and sufficient sound pressure level, due to the need for large radiating surfaces and enclosures.
Innovation Solution
An air-pulse generating device with a film structure featuring a first and second flap, actuated at ultrasonic frequencies to produce asymmetric air pressure pulses. The flaps perform differential movement to create a zigzagging slit, reducing airflow congestion and enhancing asymmetry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional speaker designs use large radiating surfaces and enclosures, then sound pressure level and fidelity are improved, but device size and complexity increase
Solution Approach 1:
The patent employs ultrasonic periodic action at frequencies above human hearing (typically 20-100 kHz) to generate air pressure pulses. The periodic opening and closing of the virtual valve at ultrasonic frequencies creates asymmetric pressure pulses that can be perceived as audible sound through rectification and demodulation effects, eliminating the need for large enclosures while maintaining sound quality
Solution Approach 2:
The invention replaces conventional mechanical speaker drivers with a virtual valve mechanism formed by differential movement of flaps. This substitution eliminates the need for physical diaphragms and large enclosures, achieving sound generation through controlled air pressure pulses created by the virtual valve's opening and closing actions
2Reliability
If flaps perform differential movement to create a virtual valve, then asymmetric air pressure pulses are produced, but airflow congestion increases
Solution Approach 1:
The patent introduces a zigzagging slit pattern that extends airflow paths in multiple dimensions rather than a single straight line. This dimensional change allows air to flow through the virtual valve opening from multiple angles and paths, reducing congestion and improving flow efficiency while maintaining asymmetric pressure pulse generation
Solution Approach 2:
The slit is patterned with varying local characteristics including zigzagging paths, different widths, and tooth-like structures at specific locations. These local quality variations optimize airflow by creating controlled turbulence and pressure differentials that reduce congestion while maintaining the asymmetric pulse characteristic needed for sound generation
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 device effectively produces asymmetric air pressure pulses, improving sound production and air movement applications by minimizing acoustic impedance and lateral airflow components, thus enhancing the overall performance of air-pulse generating devices.
Implementation Method 1
the film structure is actuated to operate at an ultrasonic frequency, and the air-pulse generating device produces a plurality of air pulses at an ultrasonic pulse rate
Implementation Method 2
the air-pulse generating device produces asymmetric air pressure pulses
Implementation Method 3
the slit is formed as a zigzagging pattern on the film structure... reducing airflow congestion and enhancing asymmetry
Data Source
AI summary
An air-pulse generating device includes a film structure including a first flap and a second flap opposite to each other. The film structure is actuated to operate at an ultrasonic frequency, and the air-pulse generating device produces a plurality of air pulses at an ultrasonic pulse rate. The first flap and the second flap are actuated to perform a differential movement to form an opening or a virtual valve. A slit is formed between the first flap and the second flap, and the opening or the virtual valve is formed because of the slit. The slit is formed as a zigzagging pattern on the film structure.