Audio Device with Movable Display for Directional Sound
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Solution Overview
Problem
Existing audio displays in mobile communications devices, such as mobile phone handsets and tablets, face challenges in reproducing low-frequency sounds and ensuring user privacy due to the emission of sound waves affecting those nearby, as the movement of the display is small and non-directional.
Innovation Solution
An audio device with a housing covered by a transparent layer, featuring a display actuating element that flexes to generate sound waves, and an air cavity with an entrance to enhance low-frequency sound reproduction and directional audio emission, reducing noise leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the display movement is increased to improve low-frequency sound reproduction, then sound quality improves, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The audio device is segmented into distinct functional zones: a first region with the display actuating element for mid-high frequencies, and a second region with the acoustic waveguide and resonant cavity for low-frequency enhancement. This segmentation allows each zone to be optimized independently, improving overall sound quality without requiring the entire display to move excessively, thus avoiding increased device complexity.
Solution Approach 2:
An acoustic waveguide structure acts as an intermediary between the display actuating element and the external environment. The waveguide includes a resonant cavity that amplifies low-frequency sounds generated by the display's movement, enabling effective bass reproduction without requiring large display excursions or complex mechanical systems.
2Reliability
If the whole display emits sound to provide audio output, then audio coverage is improved, but user privacy deteriorates as nearby people can hear the sound
Solution Approach 1:
Different regions of the audio device have different acoustic properties: the first region (display area) provides general audio coverage, while the second region (acoustic waveguide with resonant cavity) provides directional low-frequency output. This local differentiation allows the device to maintain overall audio coverage while creating a specific directional path for bass frequencies that can be oriented toward the user's ear.
Solution Approach 2:
The acoustic waveguide introduces a spatial dimension to sound emission by creating a directed acoustic path rather than omnidirectional emission. The resonant cavity and waveguide structure channel low-frequency sounds in a specific direction (toward the user's ear when the device is held normally), adding directional control to the previously omnidirectional sound field.
3Length of moving object
If the display movement is kept small to maintain device thinness, then device portability is improved, but low-frequency sound reproduction deteriorates
Solution Approach 1:
The acoustic waveguide with resonant cavity serves as a mechanical intermediary that amplifies the effect of small display movements. The resonant cavity is designed with specific dimensions to resonate at low frequencies, multiplying the acoustic output from the small displacements generated by the thin display actuating element, thus enabling bass reproduction without increasing device thickness.
Solution Approach 2:
The resonant cavity parameters (volume, shape, opening size) are specifically designed to resonate at low frequencies. By tuning these parameters, the system achieves enhanced low-frequency output from the small movements of a thin display, transforming the physical parameters of the acoustic system to compensate for the limited mechanical displacement available in a thin device.
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 effectively boosts low-frequency sound reproduction and enhances user privacy by directing sound waves, meeting telecommunications standards with reduced power requirements and minimal electronic amplification, while minimizing sound emission to those nearby.
Implementation Method 1
at least one display actuating element in the housing configured to flex the display and the layer of transparent material to generate sound waves
Implementation Method 2
There is at least one air cavity formed between the layer of display material and the housing; and an entrance formed in the layer of transparent material to allow air to pass between the air cavity and an exterior of the device
Data Source
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AI summary
An audio device is described which comprises a housing holding electronic components and having a face being substantially covered by a layer of transparent material. The audio device has a display comprising a layer of display material supported under at least part of the layer of transparent material; and at least one display actuating element in the housing configured to flex the display and the layer of transparent material to generate sound waves. There is at least one air cavity formed between the layer of display material and the housing; and an entrance formed in the layer of transparent material to allow air to pass between the air cavity and an exterior of the device.