Electrostatic Transducer Array with Varying Card Widths

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Solution Overview

Problem

Conventional loudspeakers are inefficient in converting electrical energy into audio energy, bulky due to large enclosures, and fail to efficiently produce a wide range of frequencies, with thermoacoustic speakers being particularly inefficient and cone speakers relying on mechanical resonance.

Innovation Solution

The use of an array of electrically conductive membrane transducers, such as polyester-metal membrane pumps, which generate sound through pressurized airflow, allowing for compact design and efficient sound production across a wide frequency range by utilizing electrostatic transducers with varying card widths to eliminate the need for cone drivers.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional cone speakers are used to produce sound, then mechanical motion can generate audio waves, but efficiency is low (less than 10% energy conversion) and size is bulky due to large enclosures

Engineering Contradiction:

Improveenergy conversion efficiencyVSAvoidspeaker enclosure volume

Core Design Contradiction:

Loss of energyVSVolume of stationary object

Solution Approach 1:

The patent replaces the conventional mechanical cone-driven acoustic system with an electrostatic transducer system that uses electric fields to directly move a diaphragm, eliminating the need for large mechanical enclosures and improving energy conversion efficiency from less than 10% to significantly higher levels

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention extracts and eliminates the bulky enclosure component traditionally required for cone speakers by using electrostatic transducers that can operate effectively in compact configurations without large resonant chambers

Inventive Principle:

Principle #2Taking out (Extraction)

2Adaptability or versatility

If cone speakers are designed for specific frequency ranges, then they can produce targeted audio output, but they fail to efficiently produce a wide range of frequencies due to mechanical resonance limitations

Engineering Contradiction:

Improvefrequency range coverageVSAvoidfrequency production efficiency

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

The electrostatic transducer system enables dynamic adjustment and efficient production across a wide frequency range by using electric field control rather than mechanical resonance, allowing each transducer element to respond effectively to varying frequencies without the limitations of fixed mechanical resonant frequencies

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent uses multiple electrostatic transducer elements that can be independently controlled to cover different frequency ranges, with each element optimized for specific frequency bands while collectively providing wide-frequency coverage with high efficiency

Inventive Principle:

Principle #1Segmentation

3Loss of energy

If thermoacoustic speakers are used to produce sound, then heating elements can generate sound waves, but efficiency is terribly low (well under 1% energy conversion)

Engineering Contradiction:

Improveenergy conversion efficiencyVSAvoidaudio power output

Core Design Contradiction:

Loss of energyVSPower

Solution Approach 1:

The patent replaces the inefficient thermal-to-acoustic conversion process with direct electrostatic-to-mechanical conversion, eliminating the intermediate heating step that causes energy loss and achieving significantly higher overall efficiency while maintaining or increasing audio power output

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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

This solution significantly increases audio power and efficiency, allowing for high-quality sound production with reduced size and weight, while maintaining a null sound plane for improved microphone performance and voice recognition capabilities.

Implementation Method 1

an electrostatic transducer or an array of electrostatic transducers. The electrically conductive transducers generate the desired sound by the use of pressurized airflow.

Methodology Applied

Scientific EffectElectrostatic: Electrostatics

Data Source

PatentUS10791401B2Compact electroacoustic transducer and loudspeaker system and method of use thereof

Publication Date: 2020.09.29 BRANE AUDIO LLC

AI summary

An improved loudspeaker that has a plurality of stacks of cards having electrostatic transducers, in which one stack of cards has a different width as another stack of cards in the plurality of stacks. At frequencies above 200 Hz, and at the same drive voltage and current, the stack of lesser width produced significantly greater microphone voltage as compared to the stack of greater width cards. By combining the plurality of stacks of cards with different widths, this provides for the elimination of conventional cone drivers, and provides for improved sound both above and below 200 Hz using only electrostatic transducers. It also assists in maintaining a null sound plane that is beneficial for voice recognition.