Rollable Bistable Membrane Loudspeaker for Compact Transport
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Solution Overview
Problem
Existing mobile loudspeakers face challenges in achieving good sound quality while being compact and easily transportable, as they often compromise on weight, volume, and stability due to limited installation space in smartphones.
Innovation Solution
A bistable membrane is integrated with an electromechanical transducer, allowing the membrane to switch between a stable operating state for sound playback and a compact transport state, which is achieved by using a spring steel membrane that can roll up around a cylindrical housing, reducing volume and enhancing transportability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional rigid membrane is used in mobile loudspeakers, then sound quality is improved, but volume and weight increase, reducing transportability
Solution Approach 1:
The membrane is designed to be dynamically changeable between two stable states: an extended operating state for sound playback and a rolled-up transport state for compact storage. This dynamic transformation allows the membrane to provide large surface area when needed while minimizing volume during transport, resolving the contradiction between sound quality requirements and portability needs.
Solution Approach 2:
The membrane's physical parameters (shape, volume, surface area) are changed by transitioning between bistable states. In the operating state, the membrane has large surface area and extended shape for optimal sound quality. In the transport state, the membrane rolls up to reduce volume and weight, enabling easy portability. This parameter transformation resolves the contradiction between maintaining sound quality and reducing device size.
2Ease of operation
If the membrane is made flexible and rollable, then transportability is improved, but stability and sound quality deteriorate
Solution Approach 1:
The membrane incorporates bistability, allowing it to maintain stable configurations in both extended and rolled-up states. The dynamic transition between these states enables easy transportability when rolled, while the extended stable state provides the structural integrity needed for high-quality sound playback, thus resolving the contradiction between flexibility and stability.
Solution Approach 2:
The membrane is constructed from composite materials that combine flexibility for rolling with structural stability for sound playback. This composite structure enables the membrane to be easily transported when rolled up while maintaining sufficient rigidity and stability when extended for optimal acoustic performance.
3Reliability
If the membrane is made rigid to maintain shape, then sound quality is improved, but flexibility and rollability are lost
Solution Approach 1:
The membrane exhibits dynamic adaptability through bistability, transitioning between an extended rigid-like state for sound playback and a rolled-up flexible state for transport. This dynamic behavior provides both the structural characteristics needed for high-quality sound and the flexibility required for portability, resolving the contradiction between rigidity and adaptability.
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 provides a compact, lightweight loudspeaker with improved sound quality that can easily transition between operating and transport states, addressing the need for both good sound and portability.
Implementation Method 1
an electromechanical transducer for converting electrical signals into mechanical oscillations
Implementation Method 2
the employment of piezomechanical elements would also be conceivable, which convert electrical signals into mechanical movements or oscillations
Implementation Method 3
the membrane is bistably configured to assume either a stable operating state or a stable transport state
Data Source
AI summary
The invention relates to a mobile loudspeaker apparatus for playing back sound. Mobile loudspeaker systems are often disadvantageous in that they have a poor sound quality or require equipment for a good sound quality that is not easy to transport. A loudspeaker apparatus which firstly provides a good sound quality and secondly is also easily transportable is desirable. Previously, these two requirements were often mutually exclusive. By way of a bistable membrane, or a membrane that is stable in more than two states, said membrane being coupleable to the loudspeaker apparatus, it is possible to manage the balancing act between good transportability and a good sound quality of the loudspeaker apparatus. The bistable membrane can be changed from a stable operating state into a stable transport state. By way of a slight pressure at both ends of the bistable membrane, the latter can be rolled up and consequently changed into the transport state. By way of example, in the transport state, the bistable membrane can engage around a cylindrical housing that partly or wholly encloses the loudspeaker apparatus.