Electrostatic Loudspeaker Card Stack for Thin Enclosures
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional audio speakers are bulky, inefficient, and generate physical vibrations, making them unsuitable for limited space environments like sound bars and televisions, as they require separate subwoofers for low bass frequencies and have a thick form factor.
Innovation Solution
Loudspeakers utilizing a stack of electrostatic actuator cards within a partial enclosure, which direct in-phase sound waves and use control circuitry to generate sound waves with minimal vibration, providing low bass frequencies without a separate subwoofer and a thin form factor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional cone speakers are used, then sound waves can be generated, but the speakers become bulky and require large enclosures
Solution Approach 1:
The speaker is divided into multiple electrostatic actuator cards stacked together, each card contributing to sound generation. This segmentation allows the system to achieve sufficient sound output without requiring a large enclosure volume, directly resolving the contradiction between compact size and effective sound generation.
Solution Approach 2:
The conventional mechanical cone speaker system is replaced with an electrostatic actuation system. Instead of using a mechanically moving cone within a large enclosure, electrostatic fields directly actuate the air molecules, enabling efficient sound generation in a compact form factor.
2Object-affected harmful factors
If conventional speakers are used in limited space, then they can produce sound, but they generate substantial physical vibrations causing wall or floor rattle
Solution Approach 1:
The mechanical vibration-based sound generation is replaced with electrostatic actuation. The electrostatic actuator cards use electric fields to directly move air molecules, eliminating the mechanical vibrations that cause wall and floor rattle while maintaining effective sound output in limited spaces.
3Use of energy by moving object
If conventional speakers are used, then they can produce sound, but less than ten percent of electrical energy is converted into audio energy
Solution Approach 1:
The inefficient mechanical energy conversion of conventional speakers is replaced with direct electrostatic actuation. The electrostatic actuator cards convert electrical energy to acoustic energy with significantly higher efficiency by using electric fields to directly manipulate air molecules, rather than through mechanical intermediate steps.
4Adaptability or versatility
If conventional speakers are used in limited space environments, then they can function, but they require a separate subwoofer for low bass frequencies
Solution Approach 1:
The electrostatic actuator card system is designed to handle the full audio frequency range, including low bass frequencies, within a single integrated unit. This multi-functional capability eliminates the need for separate subwoofer systems, reducing overall system complexity while maintaining adaptability across all frequency ranges.
5Length of moving object
If conventional speakers are used, then they can produce sound, but they have a thick form factor unsuitable for sound bars and televisions
Solution Approach 1:
The speaker system is segmented into multiple thin electrostatic actuator cards stacked together. This segmentation allows the achievement of sufficient sound pressure generation capability through the combined effect of multiple cards, while each individual card maintains a thin profile suitable for integration into sound bars and televisions.
Solution Approach 2:
The electrostatic actuator cards utilize composite structures combining conductive and insulating materials in thin layers. This composite construction enables effective electrostatic actuation while maintaining a thin overall form factor, resolving the contradiction between thickness and sound pressure generation capability.
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 enables lightweight, vibration-free loudspeakers that efficiently produce sound in limited spaces by using a series stack of electrostatic actuator cards to increase sound pressure and overcome backpressure in enclosures, improving efficiency and reducing physical vibrations.
Implementation Method 1
a plurality of membranes, wherein one of the membranes is positioned between two adjacent stators and electrostatically actuated based on an electric field existing between the two adjacent stators
Implementation Method 2
an electric field existing between the two adjacent stators
Implementation Method 3
The series arrangement of the card stacks increases the sound pressure that can be generated by the loudspeaker
Implementation Method 4
co-aligned vent members that enable inter-stack flow of air between the two adjacent card stacks when the series stack is generating sound waves
Data Source
AI summary
This disclosure relates to loudspeakers that use one or more stacks of electrically actuated cards that pump air through vents to produce sound waves in response to an acoustic signal. Each stack can include several electrostatic actuator cards that are stacked on top of each other and collectively operate to pump air through a vent to produce a sound wave. Each card may include an electrically conductive membrane that is pushed/pulled between two electrically conductive stators. As the membrane is pushed and pulled along a first axis, air is pumped through vents in a direction orthogonal to the first axis. In one embodiment, stacks of cards can be arranged in series to increase sound pressure generated by the loud speaker. In another embodiment, a single stack of cards can be driven with relatively high electric field strength to increase the sound pressure generated by the loud speaker.