Open-Ear Acoustic Output Structure With Split-Frequency Loudspeakers
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Solution Overview
Problem
Open-ear earphones require a specialized loudspeaker design to meet sound pressure requirements within specific frequency bands while allowing users to hear ambient sounds, which existing designs fail to address effectively.
Innovation Solution
The acoustic output device incorporates a housing with two loudspeakers, each with a magnet and diaphragm spaced apart along their vibration direction, and sound outlet holes acoustically coupled to the diaphragms, positioned to optimize sound output and projection, with one loudspeaker emitting lower frequencies than the other, and the magnets having specific magnetic pole orientations and spacings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single loudspeaker is used in open-ear earphones, then the device structure is simple, but the sound pressure requirements within specific frequency bands cannot be met
Solution Approach 1:
The patent divides the audio frequency range into different bands and uses separate loudspeakers for different frequency ranges. Specifically, it employs a first loudspeaker for low frequencies and a second loudspeaker for high frequencies, allowing each speaker to be optimized for its specific frequency band rather than requiring a single speaker to handle all frequencies effectively.
Solution Approach 2:
The patent positions the two loudspeakers at different locations within the housing, with the first loudspeaker positioned away from the ear canal opening and the second loudspeaker positioned closer to the ear canal opening. This spatial arrangement in different dimensions allows each speaker to project sound effectively in its optimal direction without blocking the ear canal.
2Reliability
If loudspeakers are positioned close to the ear canal opening to enhance sound output, then the sound pressure is improved, but the ear canal becomes blocked and ambient sound perception is reduced
Solution Approach 1:
The patent segments the sound projection function between two loudspeakers positioned at different locations. The second loudspeaker is positioned closer to the ear canal opening to project high-frequency sound directly toward the ear canal, while the first loudspeaker is positioned away from the opening to project low-frequency sound without blocking the canal, thus maintaining ambient sound perception.
Solution Approach 2:
Different regions of the housing are assigned different functions: one region (near the ear canal opening) is optimized for high-frequency sound projection, while another region (away from the opening) is optimized for low-frequency sound projection. This local optimization allows each area to contribute to its specific function without compromising the overall performance.
3Reliability
If multiple loudspeakers are used to meet sound pressure requirements, then the sound output is enhanced, but the device complexity increases
Solution Approach 1:
The patent combines two loudspeakers with different frequency responses into a single housing structure, where they work together to cover the full audio frequency range. The first loudspeaker handles low frequencies and the second loudspeaker handles high frequencies, merging their capabilities to achieve comprehensive sound coverage that would be difficult to obtain with a single speaker.
Solution Approach 2:
Each loudspeaker is designed to perform a specific function (low-frequency or high-frequency sound projection), and together they provide universal coverage across the entire audio spectrum. This multi-functional approach allows the device to deliver both bass and treble sounds effectively without requiring a complex single-speaker design.
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 device enhances sound output and ensures users can hear ambient sounds by positioning loudspeakers to project sound effectively without blocking the ear canal, improving safety and comfort.
Implementation Method 1
the first loudspeaker includes a first magnet and a first diaphragm, the first magnet and the first diaphragm are spaced apart along a vibration direction of the first diaphragm; and the second loudspeaker is accommodated within the inner cavity, and the second loudspeaker includes a second magnet and a second diaphragm
Implementation Method 2
the first loudspeaker includes a first magnet and a first diaphragm, the first magnet and the first diaphragm are spaced apart along a vibration direction of the first diaphragm
Data Source
Figure 1
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Figure 3A
AI summary
One or more embodiments of the present disclosure relate to an acoustic output device. The acoustic output device includes a housing, a support structure, a first loudspeaker, and a second loudspeaker. The housing forms an inner cavity; the support structure is configured to wear the housing on an ear without blocking an ear canal. The first loudspeaker is accommodated within the inner cavity, and the first loudspeaker includes a first magnet and a first diaphragm. The first magnet and the first diaphragm are spaced apart along a vibration direction of the first diaphragm. The second loudspeaker is accommodated within the inner cavity, and the second loudspeaker includes a second magnet and a second diaphragm. The second magnet and the second diaphragm are spaced apart along a vibration direction of the second diaphragm.