Eccentric Cap Speaker Unit for Adjustable Directivity
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Solution Overview
Problem
Existing speaker units with eccentric vibration plates face design complexity and cost increases due to the need for corresponding frame shapes, and they struggle to maintain good sound output when the bobbin's axial direction is not aligned with the front-rear direction.
Innovation Solution
A speaker unit with a cap attached to the vibration plate, where the bobbin's center axis is inclined relative to the horizontal or vertical plane, and the cap is formed in a shape eccentric to the center axis, allowing for adjustable directivity characteristics without increasing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the vibration plate is formed in an eccentric shape to suppress resonance and broaden the band, then the sound output quality is improved, but the frame shape must also be formed correspondingly which increases cost and design difficulty
Solution Approach 1:
The patent extracts the eccentric shape requirement from the frame and applies it only to the cap component. The cap is formed in an eccentric shape relative to the bobbin center axis, while the frame maintains a simple circular shape, thus achieving the desired sound output quality without increasing frame complexity or cost
Solution Approach 2:
The eccentric shape is applied locally only to the cap component rather than the entire frame structure. This localized application of asymmetry achieves the resonance suppression and bandwidth broadening effects while keeping the overall frame design simple and cost-effective
2Adaptability or versatility
If the bobbin axial direction is arranged in a direction different from the front-rear direction, then the speaker unit can be arranged in different orientations, but it becomes difficult to ensure good sound output state
Solution Approach 1:
The cap is designed with an eccentric shape relative to the bobbin center axis, creating asymmetric directivity characteristics. This asymmetry allows the speaker unit to maintain good sound output quality even when the bobbin axial direction is not aligned with the front-rear direction, enabling flexible arrangement orientations
Solution Approach 2:
The patent introduces directional control in the radial dimension through the eccentric cap shape, rather than relying solely on the axial orientation. This allows the speaker to achieve good sound output in multiple orientation configurations by utilizing the eccentric geometry's directional properties
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
This configuration enables flexible control of sound direction, ensuring good directivity and sound output without design or cost complications, even when the bobbin's axis is not aligned with the front-rear direction.
Implementation Method 1
a vibration plate is vibrated by driving a magnetic circuit to output sound... a magnetic circuit having a magnet, a yoke, and a coil
Data Source
AI summary
A good output state of sound is ensured without a cost increase. A speaker unit includes: a vibration plate; a magnetic circuit; a bobbin to which an inner peripheral portion of the vibration plate is attached and which is varied in an axial direction by the magnetic circuit; and a cap attached to the vibration plate and located to face the bobbin in the axial direction of the bobbin, in which a center axis of the bobbin is arranged in a state of being inclined with respect to a horizontal plane or a vertical plane, and the cap is formed in a shape eccentric to the center axis of the bobbin. Thus, since the cap is eccentric to the center axis in a state in which the center axis of the bobbin is inclined with respect to the horizontal plane or the vertical plane, it is possible to freely control a pointing direction in an inclined direction, good directivity characteristics can be obtained, and a good output state of sound can be ensured without a cost increase.