Earphone Driver Alignment for High-Frequency Response
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Solution Overview
Problem
Conventional canal-type earphones using multiple balanced armature driver units suffer from attenuation of high-frequency sound components due to the configuration of sound emission axes and the size of the unit case, leading to compromised frequency response and discomfort during wear.
Innovation Solution
The earphone design aligns the sound emission axis of the high-frequency driver unit with the central axis of the sound delivery tube, while positioning the sound outlet nozzle of other frequency range driver units in a retracted parallel configuration, allowing direct sound propagation and reducing the unit case size to prevent discomfort.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the sound emission axes of multiple BA driver units are arranged at specific angles to accommodate them in the unit case, then the unit case can house multiple driver units, but the high-frequency sound components are attenuated due to reflection losses
Solution Approach 1:
The patent changes the spatial arrangement of driver units from angular configuration to a linear configuration along the sound emission axis. The first BA driver unit is positioned with its sound emission axis coinciding with the central axis of the sound delivery tube, while the second BA driver unit is positioned parallel to this axis at a retracted position, eliminating angular reflections and enabling direct sound propagation to the ear canal.
2Quantity of substance
If the unit case is enlarged to accommodate multiple driver units with proper spacing, then multiple driver units can be housed, but the earphone becomes uncomfortable to wear
Solution Approach 1:
The patent positions the second BA driver unit at a retracted position along the sound emission axis, effectively nesting the driver units within a compact linear arrangement. This nested configuration allows multiple driver units to be housed in a small unit case volume, maintaining wearability comfort while accommodating multiple drivers for extended frequency response.
3Loss of energy
If the sound emission axis of the high-frequency driver is aligned with the central axis of the sound delivery tube, then direct sound propagation is achieved, but the positioning becomes more complex
Solution Approach 1:
The patent applies different positioning strategies to different driver units based on their frequency ranges. The first BA driver unit (high-frequency) is positioned with its sound emission axis coinciding with the central axis of the sound delivery tube for direct propagation, while the second BA driver unit (other frequency ranges) is positioned parallel at a retracted position. This localized differentiation optimizes sound propagation for each frequency range while maintaining overall system compactness.
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 enhances the frequency response by minimizing reflection losses and maintains a comfortable fit by avoiding the need for an enlarged unit case, ensuring comprehensive sound reproduction and wearability.
Implementation Method 1
The armature (a piece of iron plate) is vibrated by a drive current corresponding to an audio signal and vibration of the armature is transmitted to the diaphragm through a drive rod to reproduce sound waves
Implementation Method 2
a sound delivery tube that communicates with the unit case and leads a reproduced sound (sound waves) to users' ear canal
Data Source
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AI summary
An earphone (1) includes a first driver units (2d,2e) reproducing sound waves in a high-frequency range, a second driver units (2f,2g) reproducing sound waves other than the high-frequency range of the first driver units, and a unit case (3) for housing the respective driver units and a sound delivery tube (4) for leading sound waves from the driver units to a user's ear canal, the sound delivery tube (4) being formed to communicate with the unit case (3). A sound emission axis (A1) of the first driver units and a sound emission axis (A2) of the second driver units are disposed in parallel to each other, and the sound emission axis of the first driver unit passes through in an opening (8a) of the sound delivery tube (4). This construction, including multiple driver units for producing different frequency ranges, allows to provide an earphone in which attenuation of high-frequency components in particular is reduced.