Tuned Spring-Mass Resonator for Mobile Display Low-Frequency Audio
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Smaller form factor devices like smartphones face challenges in producing high-quality sound at distances due to limited packaging space and small air gaps that impede vibration, particularly in lower frequency ranges, leading to audio quality issues and discontinuities.
Innovation Solution
Tuning the spring mass resonator by adjusting components such as spring stiffness and mass to shift the fundamental frequency from 350 Hz to 700 Hz, reducing attenuation and improving uniformity in sound pressure levels across this range.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the air gap between internal components and display is reduced to save space, then device compactness is improved, but vibration quality and audio output in lower frequency ranges deteriorate
Solution Approach 1:
The patent modifies the spring mass resonator by adjusting parameters such as spring stiffness and mass to shift the fundamental frequency from 350 Hz to 700 Hz. This parameter change allows the system to compensate for the detrimental effects of small air gaps on low-frequency vibration, maintaining audio quality while preserving device compactness.
Solution Approach 2:
The patent utilizes mechanical vibration principles by tuning the spring mass resonator to operate at a higher fundamental frequency (700 Hz). This vibration-based approach enables the display to effectively radiate sound in the frequency range where small air gaps would otherwise cause significant attenuation, thereby resolving the contradiction between compactness and vibration quality.
2Reliability
If the fundamental frequency is increased from 350 Hz to 700 Hz, then sound pressure level uniformity is improved, but the resonant frequency range shifts
Solution Approach 1:
The patent deliberately changes the fundamental frequency parameter from 350 Hz to 700 Hz through spring mass resonator tuning. This parameter change is designed to improve sound pressure level uniformity across the operating range, accepting that the resonant frequency range shifts to higher frequencies where the display maintains more consistent acoustic performance.
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
Enhances audio quality by providing consistent sound pressure levels and reducing audio discontinuities in lower frequencies, resulting in more stable and aurally pleasing sound output.
Implementation Method 1
a flat panel audio loudspeaker utilizes one or more actuators to induce vibration modes in a panel
Implementation Method 2
The display 104 with the spring mass resonator 130 in an untuned condition exhibits an untuned slope of a radiated sound pressure level that changes from a positive slope at a first frequency less than 350 Hz. to a negative slope at a second frequency between 350 Hz. and 700 Hz.
Implementation Method 3
In some instances of smaller form factor devices, such as a mobile phone, a small air gaps between components and a panel can create significant air stiffness effects that impede the vibration of a panel
Data Source
AI summary
Mobile computing devices and methods for manufacturing mobile computing devices and tuning a spring mass resonator of a distributed mode loudspeaker in such devices are disclosed. A mobile computing device includes a display to which the spring mass resonator is affixed. At least one component of the spring mass resonator is modified to increase a frequency response of the display within at least a portion of a frequency range between 350 Hz. and 700 Hz.