Speaker Diaphragm Rib Design for Inverse Resonance Control
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Solution Overview
Problem
Conventional speaker devices in portable electronic devices suffer from inverse resonance between the dome-shaped diaphragm and the edge portion, leading to distortion in high tone ranges and deterioration of acoustic characteristics due to reduced rigidity and size constraints.
Innovation Solution
A vibrating body for an acoustic transducer is designed with a diaphragm comprising a first and second vibrating part, an edge portion, and radial first reinforcing portions extending from the second vibrating part to the edge portion, enhancing rigidity and suppressing inverse resonance by adjusting the height and shape of these reinforcing elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the thickness of the diaphragm and edge portion is reduced to decrease weight, then the weight is reduced, but the rigidity decreases causing deformation and rolling phenomenon
Solution Approach 1:
The diaphragm is divided into multiple vibrating parts (first vibrating part and second vibrating part) with different functions. The first vibrating part handles low-frequency vibrations while the second vibrating part handles high-frequency vibrations, allowing each part to be optimized for its specific frequency range and reducing the need for excessive thickness throughout the entire diaphragm.
Solution Approach 2:
Different regions of the diaphragm and edge portion are given different thicknesses and structural properties. The edge portion has varying thickness to provide localized reinforcement where needed while maintaining overall weight reduction. The first and second vibrating parts have different structural characteristics optimized for their respective frequency ranges.
2Volume of moving object
If the size of the speaker device is reduced for portability, then the device becomes more portable, but the resonance frequency increases causing distortion in high tone ranges
Solution Approach 1:
The vibration system is segmented into multiple vibrating parts that operate at different frequency ranges. This segmentation allows the speaker to maintain accurate frequency response across the audible spectrum even in a compact size, as each vibrating part is optimized for its specific frequency range rather than requiring a single large diaphragm to handle all frequencies.
Solution Approach 2:
The invention introduces a new dimension of vibration control by creating multiple vibrating parts that can vibrate independently in different modes. This multi-dimensional vibration approach allows compact speaker design while maintaining accurate frequency response, as the different vibrating parts compensate for each other's limitations in a small form factor.
3Weight of moving object
If the edge portion is made thinner to reduce weight, then the weight is reduced, but inverse resonance occurs between the diaphragm and edge portion
Solution Approach 1:
The vibration system is divided into separate vibrating parts with distinct resonance characteristics. The first vibrating part and second vibrating part have different resonance frequencies, which prevents inverse resonance between the diaphragm and edge portion even when the edge portion is made thinner for weight reduction.
4Strength
If reinforcing structures are added to increase rigidity, then the rigidity is improved, but the weight and complexity increase
Solution Approach 1:
The edge portion is designed with non-uniform thickness, providing localized reinforcement only in the regions where it is structurally necessary to prevent deformation and rolling phenomenon. Other regions maintain thinner profiles to minimize weight, achieving an optimal balance between rigidity and weight without requiring comprehensive reinforcing structures throughout the entire edge portion.
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 moves the high resonance frequency outside the audible range, improving the acoustic characteristic of the speaker device with a flat frequency response and reduced distortion, while maintaining a compact size.
Implementation Method 1
a first reinforcing portion is formed so as to extend from the second vibrating part to the edge portion in a radial direction
Implementation Method 2
a diaphragm that vibrates in response to an electric signal applied to a voice coil and emits a sound wave
Data Source
AI summary
An example vibrating body for the acoustic transducer may include a diaphragm including a first vibrating part and a second vibrating part located at an outer circumference of the first vibrating part. A coil is configured to vibrate the diaphragm. An edge portion is located at an outer circumference of the diaphragm. A plurality of ribs are provided outside of the coil on the second vibrating part formed integrally with the second vibrating part. A plurality of ribs is provided on the edge portion formed integrally with the edge portion. None of the integrally formed ribs is provided inside of the coil on the first vibrating part. The ribs provided on the second vibrating part are formed in an inner circumferential side of regions of the edge portion, the regions being located between the ribs provided on the edge portion next to each other.