Panel-Form Loudspeaker Using Device Cover as Vibration Plate
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Solution Overview
Problem
Conventional mobile device loudspeakers with small diameters (10-15 mm) have limited frequency response, especially in the low frequency region below 700 Hz, due to their small vibration plates, and using larger speakers is impractical as devices shrink in size, while panel-form loudspeakers using displays as vibration plates face issues with glass breakage and unadjustable sound performance.
Innovation Solution
A panel-form loudspeaker design utilizing the back or front cover of mobile devices as a vibration plate, incorporating a diaphragm and piezoelectric plates to generate sound, with recesses, stepped portions, and sound holes for improved vibration and sound transmission, allowing for enhanced low-frequency sound reproduction without increasing device size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional small-diameter speakers (10-15 mm) are used, then the device size is kept compact, but the frequency response is limited especially in low frequency region below 700 Hz
Solution Approach 1:
The patent merges the speaker function with the device back cover by making the back cover itself serve as the vibration plate. This integration allows the entire back cover surface to function as the speaker diaphragm, effectively creating a large-diameter speaker without increasing device volume. The back cover is directly driven by the voice coil assembly to produce sound waves, eliminating the need for separate speaker housings and mounting structures.
Solution Approach 2:
The back cover serves multiple functions: it acts as both the structural housing component and the speaker vibration plate. This multi-functionality allows the same component to provide both mechanical protection and acoustic output, particularly for low frequency sounds, without requiring additional space or components.
2Reliability
If panel-form loudspeaker using display as vibration plate is used, then low frequency sound is generated, but the glass plate is easy to be broken by actuator vibration
Solution Approach 1:
The patent extracts the vibration plate function from the display assembly and assigns it to the back cover instead. By removing the display from the speaker function, the fragile glass plate is no longer subjected to actuator vibrations, eliminating the risk of breakage while preserving the low frequency sound reproduction capability through the back cover vibration.
Solution Approach 2:
The back cover serves as an intermediary component that receives vibration from the voice coil and transmits it to generate sound. This intermediary structure protects the display assembly from direct mechanical stress while still enabling effective low frequency sound production through the back cover's vibration.
3Reliability
If display is used as vibration plate, then low frequency sound is generated, but sound performance cannot be adjusted once display is fixed
Solution Approach 1:
The patent implements a adjustable speaker assembly that can be positioned at different locations on the back cover and oriented at different angles. The voice coil assembly and magnet assembly can be dynamically adjusted to optimize sound performance for different usage scenarios, providing adaptability that fixed display-based solutions cannot achieve.
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 enhances low-frequency sound reproduction in mobile devices by using the device covers as vibration plates, improving sound performance and durability while maintaining compact device dimensions.
Implementation Method 1
incorporating a diaphragm and piezoelectric plates to generate sound
Data Source
AI summary
A panel-form loudspeaker is disclosed. The panel-form loudspeaker includes a lower cover including a recess, and a vibration acoustic unit facing the recess with a periphery thereof fixed on the lower cover for actuating the lower cover to vibrate and generate sound.