Single MEMS Microphone with Dual Sound Inlets for Directional Pickup
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Solution Overview
Problem
Conventional MEMS microphones in mobile devices are omnidirectional, limiting the ability to implement directional or bidirectional sound recording, and using multiple microphones for directional control occupies significant space and incurs high costs.
Innovation Solution
A single MEMS microphone with dual sound inlet holes and damping pieces to alter sound pressure amplitude and phase, enabling directional or bidirectional pickup without additional microphones.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a single omnidirectional MEMS microphone is used, then the device occupies small space and has low cost, but directional or bidirectional sound pickup cannot be implemented
Solution Approach 1:
The single microphone's sound pickup function is segmented into multiple independent paths by providing multiple sound inlet holes (first sound inlet hole and second sound inlet hole) positioned at different locations and orientations. Each inlet hole receives sounds from different directions and feeds them to different regions of the diaphragm, enabling directional and bidirectional pickup patterns without using multiple microphones.
Solution Approach 2:
The patent transitions from a single sound inlet to multiple sound inlets positioned in different spatial dimensions. The first sound inlet hole is positioned at a first position and the second sound inlet hole at a second position, creating spatial separation that enables different pickup patterns. This dimensional approach allows a single microphone to achieve what traditionally required multiple microphones.
2Adaptability or versatility
If multiple microphones are used to achieve directional sound pickup, then directional recording can be implemented, but the device occupies large space and incurs high cost
Solution Approach 1:
The patent merges the functions of multiple microphones into a single MEMS microphone device. By integrating multiple sound inlet holes and corresponding damping pieces within one microphone housing, the patent achieves directional and bidirectional pickup capabilities that traditionally required multiple separate microphones, thereby reducing the total space occupied and lowering component costs.
Solution Approach 2:
The single MEMS microphone is designed to perform multiple functions: omnidirectional pickup, directional pickup, and bidirectional pickup. By adjusting the damping factors of the damping pieces and configuring the sound inlet holes appropriately, the same microphone structure can adapt to different sound pickup requirements, making it a universal solution replacing multiple specialized microphones.
3Adaptability or versatility
If multiple microphones are used to achieve bidirectional sound pickup, then front and back sound recording can be implemented, but use cost increases
Solution Approach 1:
The patent introduces adjustable damping pieces in the sound paths from different inlet holes to the diaphragm. By dynamically adjusting the damping factors of these damping pieces, the microphone can switch between different pickup patterns including bidirectional mode, where sounds from front and back are picked up while side sounds are suppressed. This dynamic adjustment capability eliminates the need for multiple fixed-pattern microphones.
4Adaptability or versatility
If conventional single sound inlet MEMS microphone is used, then manufacturing is simple, but sound pickup directionality cannot be controlled
Solution Approach 1:
The patent applies different damping characteristics to different sound paths by placing damping pieces with specific damping factors in the sound paths from different inlet holes. Each damping piece is tailored to its specific position and function, creating local quality variations that enable directional control. This localized approach to damping allows directionality control without requiring complete redesign of the entire microphone structure.
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
Improves directional and bidirectional sound pickup efficiency while minimizing space and cost by using a single microphone with adjustable damping factors.
Implementation Method 1
a damping piece, configured to alter an amplitude value and a phase that are of a sound pressure acting on the diaphragm
Implementation Method 2
The damping piece is located on a path on which a sound wave passes through the second sound inlet hole and acts on the other side of the diaphragm
Data Source
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AI summary
This application discloses a terminal device, including a housing, a display screen, a microphone, and a damping piece. A first sound inlet hole is disposed on the back of the housing, and a second sound inlet hole is disposed on the front of the display screen. A microphone housing and a microphone circuit board form a microphone chamber. A chip chamber is formed in a micro-electro-mechanical system chip. The chip chamber is connected to the outside of the back of the housing through the first sound inlet hole, and the microphone chamber is connected to the outside of the front of the display screen through the second sound inlet hole, so that a sound wave from the back of the housing passes through the first sound inlet hole and acts on one side of a diaphragm, and a sound wave from the front of the display screen passes through the second sound inlet hole and acts on the other side of the diaphragm. The damping piece is located on a path on which a sound wave passes through the second sound inlet hole and acts on the other side of the diaphragm, so that the sound wave entering from the second sound inlet hole passes through the damping piece and acts on the other side of the diaphragm. In this application, comparatively good directivity of the microphone can be implemented, a directional sound pickup effect or a bidirectional sound pickup effect of the terminal device can be improved, comparatively small space is occupied, and use costs are comparatively low.