Variable Acoustic Cavity Speaker Layout for Foldable Electronics

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Loudspeakers in mobile electronic devices face challenges in producing high-quality audio and high sound pressure levels due to limited acoustic cavity size, which is constrained by the device's inner and outer dimensions.

Innovation Solution

An audio generating arrangement with moveable bodies forming an acoustic cavity that adjusts its volume in response to the movement of these bodies, allowing a larger cavity without increasing the device's outer dimensions, comprising a foldable display module and a sliding mechanism to enhance sound quality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If the acoustic cavity size is increased to improve audio quality and sound pressure levels, then the audio performance is improved, but the outer dimensions of the electronic device must be increased

Engineering Contradiction:
Improveaudio qualityVSAvoiddevice dimensions
Core Design Contradiction:
Manufacturing precisionVSLength of stationary object

Solution Approach 1:

The patent applies the dynamics principle by making the acoustic cavity volume variable rather than fixed. The cavity volume changes dynamically in response to the movement of moveable bodies (such as display modules or keyboard assemblies) within the device. This allows the system to achieve larger effective cavity volumes for improved audio performance only when needed, while maintaining compact device dimensions when the moveable bodies are in positions that minimize cavity volume.

Inventive Principle:
Principle #15Dynamics

2Power

If the acoustic cavity volume is increased to achieve higher sound pressure levels, then the loudness is improved, but the device size must be increased

Engineering Contradiction:
Improvesound pressure levelVSAvoiddevice volume
Core Design Contradiction:
PowerVSVolume of stationary object

Solution Approach 1:

The invention utilizes dynamic adjustment of the acoustic cavity volume through moveable bodies that change the available space for sound wave propagation. When higher sound pressure levels are required, the moveable bodies position themselves to maximize the cavity volume. This dynamic adaptation allows the system to achieve high power output temporarily without permanently increasing the device volume.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements the nesting principle by placing moveable functional bodies (such as display modules or keyboards) within the device housing in such a way that their movement creates variable acoustic cavity spaces. These moveable bodies effectively nest within the device structure, and their repositioning creates or expands acoustic cavities without requiring additional dedicated space for the audio function.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Manufacturing precision

If the acoustic cavity size is increased to improve audio clarity, then the sound quality is improved, but the available internal space is reduced

Engineering Contradiction:
Improveaudio clarityVSAvoidinternal space
Core Design Contradiction:
Manufacturing precisionVSVolume of stationary object

Solution Approach 1:

The system dynamically adjusts the acoustic cavity volume to provide optimal audio clarity only when needed. The moveable bodies can be repositioned based on operational requirements, allowing the cavity to expand for improved audio clarity during audio playback modes while contracting or being reconfigured when other functions require the internal space.

Inventive Principle:
Principle #15Dynamics

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 improved audio quality and higher sound pressure levels by dynamically adjusting the acoustic cavity volume, enhancing the user experience without additional components or increased device size.

Implementation Method 1

at least one loudspeaker

Methodology Applied
Scientific EffectElectroacoustic transduction:

Data Source

PatentEP4085649B1Audio generating arrangement and electronic device comprising such arrangement
Publication Date: 2026.04.22 HUAWEI TECH CO LTD
  • EP4085649B1 patent drawingFigure 1(a)~2(b)
  • EP4085649B1 patent drawingFigure 3~4b
  • EP4085649B1 patent drawingFigure 5a~6b

AI summary

An audio generating arrangement (1) for an electronic device (10), the arrangement (1) comprising at least one loudspeaker (2), a first body (3), and a second body (4) at least partially enclosing the loudspeaker (2). At least one of the first body (3) and the second body (4) is moveable with respect to the other body (3, 4). An acoustic cavity (5) is formed by the loudspeaker (2) and at least one of the first body (3) and the second body (4). A volume of the acoustic cavity (5) is configured to increase or decrease in response to movement of the first body (3) or the second body (4). Implementing the arrangement in an electronic device enables increasing the volume of the acoustic cavity without also increasing the outer dimensions of the device. An increase in the volume of the acoustic cavity results in improved audio quality, higher sound pressure levels, and lower frequencies.