CN118509776A - Electret microphone - Google Patents

Abstract

The application relates to the field of microphone technology, in particular to an electret microphone, which comprises a shell, wherein the shell is used for bearing and protecting circuit elements; a back plate disposed within the housing, the back plate being coated with electret material; the vibration assembly comprises a plurality of layers of vibration diaphragms, is arranged in the shell and is opposite to the backboard; the elastic sheet is positioned between the backboard and the vibration component, one end of the elastic sheet is fixed on the shell, and the other end of the elastic sheet is abutted with the vibration component; and the circuit board is electrically connected with the backboard and the vibration component and is used for signal amplification and processing circuits. The application has the effect of relieving the problem that the frequency response of the related electret microphone is limited and is easy to generate distortion.

Description

Electret microphone

Technical Field

The application relates to the field of microphone technology, in particular to an electret microphone.

Background

Electret microphones have been widely used in various audio capturing devices since their advent due to their high stability, low cost and excellent electroacoustic conversion efficiency. From professional-grade recording equipment to daily consumer electronics such as mobile phones, smart home devices and high-fidelity audio systems, the development of electret microphones has been an important force to push sound technology forward.

However, with the increasing demands on sound quality, some limitations also occur with conventional electret microphones. Firstly, the frequency response range and sensitivity are insufficient, the optimal sound capturing range is difficult to achieve or the sound capturing range is adapted to complex environmental changes, and when the sound signals in a wide frequency range are processed, the fidelity and dynamic response of the sound are limited, so that the performance such as nonlinear distortion is insufficient.

Thus, the related electret microphone has a problem that the frequency response is limited and distortion is easily generated.

Disclosure of Invention

In order to alleviate the problem that the frequency response of the related electret microphone is limited and is easy to generate distortion, the application provides an electret microphone.

The electret microphone provided by the application adopts the following technical scheme:

an electret microphone comprising:

A housing for carrying and protecting the circuit elements;

a backplate disposed within the housing, coated with electret material;

The vibration assembly comprises a plurality of layers of vibration diaphragms, is arranged in the shell and is opposite to the backboard;

The elastic sheet is positioned between the back plate and the vibration component, one end of the elastic sheet is fixed on the shell, and the other end of the elastic sheet is abutted against the vibration component;

and the circuit board is electrically connected with the backboard and the vibration component and is used for a signal amplifying and processing circuit.

By adopting the technical scheme, the structure of the multi-layer vibrating diaphragm is adopted in the vibrating assembly, each layer of diaphragm is optimized for a specific frequency range, the response capability of the microphone to sounds with different frequencies is enhanced, and the accuracy and quality of sound capturing are improved, so that broader frequency response and finer sound restoration are realized as a whole. The housing provides physical protection and acoustic isolation, reducing interference from external environmental noise. The back plate is coated with electret material to form stable electrostatic field, which provides basis for converting sound into electric signal. The arrangement of the elastic sheet ensures a proper distance between the vibrating diaphragm and the back plate, maintains the stability of the microphone capacitor, and simultaneously allows the vibrating diaphragm to vibrate freely to respond to sound waves. The circuit board is responsible for carrying out necessary amplification and processing on the sound signals converted by the vibrating diaphragm, and ensures the definition and usability of output signals.

Optionally, an acoustic transparent layer is disposed between the vibrating diaphragms for coupling.

By adopting the above technical solution, in an electret microphone, the vibrating diaphragms are coupled by an acoustically transparent layer, which allows, first, sound waves to be efficiently transferred from one vibrating diaphragm to another without introducing excessive sound attenuation, thereby preserving the integrity and clarity of the sound signal. Second, this coupling creates a mechanical link between the different diaphragms, allowing them to respond to sound waves in a coordinated manner, helping to expand the frequency response range of the microphone and improving the capture of sound details.

Optionally, an adjusting structure is arranged between the vibrating diaphragms to adjust the coupling degree between the vibrating diaphragms.

By adopting the technical scheme, in the design of the electret microphone, the adjusting structure is introduced, the adjusting structure allows the microphone to dynamically adjust the coupling strength between the vibrating diaphragms, the response of the microphone to sounds with different frequencies can be optimized, the resolution and quality of the sounds can be improved, different sound environments or specific sound requirements can be met, and the application performance of the microphone in a changeable environment can be enhanced. At the same time, adjusting the degree of coupling can help reduce unwanted acoustic interference between different vibrating diaphragms, thereby improving the clarity and degree of restoration of sound.

Optionally, the adjustment structure includes at least one layer of piezoelectric material disposed in the acoustically transparent layer and changing thickness in response to an electrical signal.

By adopting the technical scheme, at least one piezoelectric material layer is arranged in the acoustic transparent layer and responds to the electric signal to change the thickness, and the microphone is allowed to dynamically adjust the coupling degree between the vibrating diaphragms by changing the thickness of the piezoelectric material layer, so that the fine control on sound signals is realized, the microphone can adapt to different sound environments, the response to specific frequencies is optimized, and the sensitivity and the definition of sound capture are improved. In addition, as the piezoelectric material layer is directly integrated in the acoustic transparent layer, the response speed is high, and the acoustic characteristics of the microphone can be adjusted in real time, so that the microphone can respond to rapidly-changed sound signals. This fast speed adjustment capability is particularly important for application scenarios requiring real-time sound analysis and processing.

Optionally, the circuit board is provided with a feedback system that adjusts the layer of piezoelectric material based on microphone output.

Through adopting above-mentioned technical scheme, with feedback system integration to the circuit board in, based on the microphone output adjusts the piezoelectricity material layer, the microphone not only can respond to sound environment passively, but also can initiatively adjust self acoustic performance in order to adapt to different sound conditions, has strengthened intelligent and self-adaptation ability. The feedback system enables the microphone to dynamically adjust the thickness of the piezoelectric material layer according to the real-time analysis result of the output signal of the microphone, allows the microphone to automatically optimize the performance of the microphone, and improves the response capability and accuracy to specific sound events.

Alternatively, the diaphragms are made of materials with different acoustic properties and have different frequency response intervals.

By adopting the technical scheme, the vibrating diaphragms made of materials with different acoustic characteristics are used, so that each layer of vibrating diaphragms has different frequency response intervals, each layer of vibrating diaphragms can be optimized for a specific frequency range, the whole microphone can cover wider frequency response, the microphone can simultaneously and effectively capture low-frequency and high-frequency sounds, and more comprehensive sound capturing capacity is provided. In addition, the vibrating diaphragms made of different materials can reduce distortion at specific frequencies, enhance definition and detail of sound, and the multilayer structure is beneficial to balancing the overall performance of sound, so that the output is more natural and real.

Optionally, a damping layer is disposed between the vibrating diaphragm and the housing.

By adopting the technical scheme, the damping layer can effectively reduce the resonance phenomenon of the system. The damping layer helps to stabilize the motion of the vibrating diaphragm by absorbing part of the vibration energy, and reduces distortion caused by resonance. Meanwhile, by reducing resonance and vibration of non-target sound, the damping layer is helpful to improve definition and restoration degree of sound, so that sound output by the microphone is more natural and real. In addition, the damping layer can also provide physical protection, reduce the direct impact that the vibrating diaphragm receives because of external vibrations or striking, increase durability and the reliability of microphone.

Alternatively, the thickness of each layer of the vibrating membrane is different, and the thickness gradually increases from the sound source side to the back plate side.

By adopting the technical scheme, the membrane thinner at the sound source side is more suitable for capturing high-frequency sound, and the response to the high-frequency sound wave is more sensitive, so that the high-frequency sound can be effectively transmitted and captured, and meanwhile, the attenuation possibly generated when the high-frequency sound passes through the thicker membrane is avoided. The gradually thickened diaphragm is beneficial to enhancing the capturing capability of the microphone to low-frequency sound, and the diaphragm can more effectively respond to low-frequency sound waves along with the thickening of the diaphragm to the back plate side, so that the low-frequency response of the microphone is enhanced.

Optionally, the shell is a double-layer shell structure, and an air layer or a sound absorbing material is sandwiched between the shell and the shell.

By adopting the technical scheme, the double-layer shell structure provides a remarkable acoustic isolation effect, and the air layer or the sound absorbing material can effectively absorb or isolate external sound, so that the sound capture inside the microphone is not influenced by external environment, and the interference of external noise is reduced. In addition, the double-layer shell structure can reduce the influence of external vibration on the internal components of the microphone, protect the internal sensitive elements from damage or performance reduction caused by vibration, and improve the durability and service life of the microphone.

Optionally, an acoustic hole is formed on a side, close to the vibration component, of the housing, and sound from a desired direction is captured.

By adopting the technical scheme, the acoustic holes are formed in the specific positions, the microphone can more effectively capture the sound from the expected direction, the directivity of the microphone is enhanced, and the microphone can more accurately capture the target sound source in specific applications such as conference systems, stage sound or directional recording. The acoustic holes help to reduce acoustic signals from non-target directions, thereby reducing interference from background noise. By precisely controlling the path of sound entering the microphone, the acoustic holes are beneficial to optimizing the transmission of sound waves, reducing loss and distortion in the sound transmission process, increasing the signal-to-noise ratio and improving the definition of sound, thereby improving the overall quality of sound.

In summary, the present application includes at least one of the following beneficial technical effects:

1. By adopting the structure of the multi-layer vibrating diaphragms, each layer of diaphragm is optimized for a specific frequency range, the response capability of the microphone to sounds with different frequencies is enhanced, and wider frequency response and finer sound restoration are realized;

2. The feedback system analyzes the output signals in real time to dynamically adjust the thickness of the piezoelectric material layer, so as to dynamically adjust the coupling degree between the vibrating diaphragms, achieve fine control on sound signals, and enable the microphone to adapt to different sound environments;

3. By controlling the thickness and arrangement of the vibrating diaphragms, while having excellent response and capture capabilities for high frequency sound waves and low frequency sound waves, a more comprehensive and realistic sound experience is provided.

Drawings

Fig. 1 is an overall schematic diagram of an electret microphone in an embodiment of the application.

Fig. 2 is a schematic view of an electret microphone structure according to an embodiment of the application.

FIG. 3 is a schematic view of a spring plate according to an embodiment of the present application.

Fig. 4 is an enlarged view of area a in an embodiment of the present application.

Reference numerals illustrate:

1. a housing; 11. an acoustic hole; 2. a back plate; 3. a vibration assembly; 31. a vibrating diaphragm; 32. an acoustically transparent layer; 33. a piezoelectric material layer; 34. a damping layer; 4. a spring plate; 5. a circuit board.

Detailed Description

The present application will be described in further detail below with reference to the accompanying drawings.

The embodiment of the application discloses an electret microphone.

Referring to fig. 1 and 2, an electret microphone comprises a housing 1, a backplate 2, a vibrating assembly 3, a spring plate 4 and a circuit board 5, each of which is intended to optimize the overall performance of the microphone. The shell 1 provides physical protection for the internal components of the microphone, avoids mechanical damage and invasion of environmental factors such as dust and moisture, has an acoustic isolation function, and effectively reduces interference of external environmental noise on the performance of the microphone, thereby improving the purity and accuracy of sound capture.

The back plate 2 is arranged inside the shell 1 and is opposite to the vibration component 3, and is coated with electret materials, so that a necessary electrostatic field is provided for the microphone, the electrostatic field is the key of converting sound signals into electric signals, is the basis for capturing and converting sound waves, and ensures the effective conversion and transmission of the sound signals.

Referring to fig. 2 and 3, the elastic sheet 4 is located between the back plate 2 and the vibration component 3, one end of the elastic sheet is fixed on the housing 1, and the other end of the elastic sheet is abutted against the vibration component 3, so that a proper distance between the vibration diaphragm 31 and the back plate 2 is ensured, stability of an internal capacitor of the microphone is maintained, and free vibration of the vibration diaphragm 31 under the action of sound waves is ensured.

Finally, the circuit board 5 is electrically connected with the backboard 2 and the vibration component 3, and is used for amplifying and processing the sound signals converted by the vibration component 3, so that nondestructive transmission and effective processing of the sound signals are ensured, and finally, the output sound signals are clear and accurate, and the requirement of high-quality sound capture is met.

Wherein the shell 1 adopts a double-layer shell structure, and the interlayer is filled with high-efficiency sound absorbing materials. The double-layer shell not only enhances the acoustic isolation effect, but also effectively prevents the invasion of environmental noise and interference sound by absorbing or isolating external sound waves, and ensures that the inside of the microphone can capture sound in a purer acoustic environment. In addition to the acoustic isolation function, the double shell structure provides additional mechanical protection for the microphone. By reducing vibration and impact from the outside, the sensitive element inside the microphone is protected, and vibration-related damage or performance degradation is prevented, thereby prolonging the service life of the microphone and improving the reliability thereof.

The acoustic holes 11 are provided in the side of the housing 1 of the microphone, taking into account the effective capturing of sound, as well as the directionality and quality of the sound. The acoustic holes 11 are directed towards the inner vibrating assembly 3, forming a precise sound channel, so that the microphone can more intensively capture sound waves coming from a specific direction, which is important for applications requiring a high degree of directivity.

Meanwhile, the acoustic holes 11 obviously reduce sound signals from other directions, and effectively reduce interference of non-target sounds, so that a high signal-to-noise ratio is maintained in a complex sound environment, and the definition and purity of target sounds are ensured. Through the acoustic holes 11, the transmission path of the sound wave is optimized, reflection and scattering phenomena possibly occurring in the transmission process are reduced, sound distortion is reduced, and the integrity of the sound signal is improved.

In addition, through the acoustic hole 11, the microphone not only can improve the response sensitivity to the target sound source, but also can control the incoming angle and range of sound to a certain extent, thereby enhancing the practicability and flexibility of the microphone in specific application scenes.

In an electret microphone the vibrating assembly 3, towards which the acoustic holes 11 are directed, is a complex set of multi-layer vibrating diaphragms 31 structures, wherein each layer of vibrating diaphragms 31 is made of a material with different acoustic properties and each layer is designed to have an optimal response to a specific frequency range. This multi-layer structure enables the microphone to operate over a wider frequency response range, thereby enabling simultaneous capture of low and high frequency sounds. This not only expands the application range of the microphone, but also enhances its adaptability in various sound environments.

The cooperative operation of the multiple diaphragms 31 also helps balance the sound performance of the overall microphone, ensuring the naturalness and realism of the output sound, thereby providing a high quality sound output in a variety of use scenarios.

In the electret microphone, the thickness variation of each layer of the vibrating diaphragm 31 is carefully designed, and the thickness of the diaphragm gradually increases from the side near the acoustic hole 11 to the back plate 2 side. This graduated thickness configuration provides microphones with specific response to sounds of different frequencies, enhancing their diversity and flexibility in frequency coverage.

On the sound source side, a thinner diaphragm 31 is used to optimize the capturing of high frequency sound. Because of its relatively low mass, these thin films are capable of responding quickly to high frequency sound waves, thereby providing sensitive and accurate capture of high frequency sound signals that are rich in detail. This design reduces the potential attenuation of high frequency sound as it passes through the diaphragm, ensuring the clarity and integrity of the high frequency sound.

As the diaphragm gradually thickens toward the back plate 2 side, the capturing ability of low-frequency sound gradually increases. Thicker diaphragms can respond more effectively to low frequency sound waves due to their increased mass, which is critical for capturing deep bass or background noise. Such a configuration ensures sensitivity and response capability of the microphone in the low frequency range, enhancing the overall sound capture quality.

Furthermore, a damping layer 34 is provided between the diaphragm 31 and the housing 1, which not only improves the quality of sound but also enhances the physical stability of the microphone. The damping material is specially designed to absorb and disperse the excess energy generated by the moving diaphragm, effectively reducing the resonance phenomenon of the system and stabilizing the dynamic response of the vibrating diaphragm 31. The sound distortion caused by system resonance is reduced, and the real restoration of the sound signal is ensured. In addition, the damping material layer can effectively isolate vibration and noise from the shell 1, and particularly in an environment with high sound pressure level, the definition of sound can be remarkably improved.

From the viewpoint of physical protection, the damping layer 34 also provides an additional protection layer for the vibration diaphragm 31 against direct influences of external impact and vibration, thereby increasing the overall durability and long-term stability of the microphone, ensuring that the microphone maintains reliable performance even in a severe use environment, and prolonging its service life.

Referring to fig. 4, the vibration diaphragms 31 are coupled through an acoustically transparent layer 32, and the acoustically transparent layer 32 can promote the sound wave to be effectively and almost non-attenuated to be transmitted between the adjacent vibration diaphragms 31, so that the original integrity and definition of the sound signals from the source to the output can be maintained, and the barrier-free sound wave transmission mechanism avoids the attenuation possibly occurring in the transmission process between the diaphragms, thereby ensuring the high quality of the sound output.

Further, the acoustically transparent layer 32 not only serves to maintain the transmission efficiency of sound waves, but also establishes a mechanical connection between the different diaphragms 31. This association allows the layers of the diaphragm to vibrate cooperatively in response to sound waves. Such a synergistic effect not only enhances the response sensitivity of the diaphragm 31 to sound waves, but also helps to capture a wider frequency range, and can effectively capture and restore both low-frequency booming sounds and high-frequency fine tone colors.

An acoustically transparent layer 32 has embedded therein a conditioning structure comprising at least one layer 33 of piezoelectric material providing acoustic conditioning capability to the microphone. The piezoelectric material layer 33 is capable of varying its thickness in response to an electrical signal, thereby finely adjusting the degree of coupling between the vibrating diaphragms 31, so that the microphone can not only provide optimized performance under static conditions, but also dynamically adapt to varying sound environments.

By adjusting the thickness of the piezoelectric material layer 33, the transmission efficiency and the interaction strength of the sound waves between the vibrating diaphragms 31 can be changed, so that the frequency response and the sensitivity of the sound capturing of the microphone can be carefully controlled, and the microphone can realize the optimal sound performance under different application scenes, such as a noisy background or a situation requiring capturing of fine sounds.

In addition, the integration of the piezoelectric material layer 33 into the acoustically transparent layer 32 enables the tuning structure to respond quickly to electrical signals, enabling real-time tuning of acoustic properties. For applications requiring a fast response to environmental changes, such as real-time audio monitoring, dynamic sound scene analysis, etc., it is particularly critical. The microphone allows the microphone to quickly adjust the acoustic properties of the microphone when receiving a new sound signal or changing the environmental conditions, and ensures continuous optimization and accuracy of sound capture.

The dynamic tuning capability of the piezoelectric material layer 33, controlled by a feedback system on the circuit board 5, is capable of autonomously tuning the acoustic performance based on the analysis of the real-time output signal. The core of the feedback mechanism is its real-time and accuracy, which is capable of capturing small changes in microphone output and adjusting the thickness of the piezoelectric material layer 33 accordingly, thereby affecting the degree of coupling between the vibrating diaphragms 31.

The feedback system allows the microphone response to be no longer limited to passive sound reception. In contrast, the sound-emitting device can actively adapt to the sound change of the environment, and adjust the acoustic characteristics of the sound-emitting device according to different sound scenes, so that the flexibility of the microphone is improved, and the application potential of the sound-emitting device in a changeable environment is greatly enhanced.

The implementation principle of the electret microphone provided by the embodiment of the application is as follows:

In electret microphones, a multi-layer vibrating diaphragm 31 structure is employed, wherein the diaphragms of each layer are optimized for a specific frequency range. Not only the response capability of the microphone to sounds with various frequencies is enhanced, but also the frequency response range is widened. The specialized design of each layer of diaphragm allows the microphone to accurately capture various sound waves from low to high frequencies, thereby achieving finer, more accurate sound reproduction. The multi-layer structure ensures that the microphone is able to capture the full spectrum of sound, providing a richer and dynamic sound experience.

Further, the feedback system built in the microphone monitors the output signal on the circuit board 5 in real time, and dynamically adjusts the thickness of the piezoelectric material layer 33 based on the data, so that the microphone can dynamically adjust the coupling degree between the vibrating diaphragms 31, fine control of sound signals is realized, the microphone can not only passively respond to sound environments, but also actively adjust the acoustic performance of the microphone to adapt to changeable sound conditions, and therefore excellent sound capturing performance can be maintained in various environments.

In addition, by skillfully controlling the thickness of each layer of the vibration film 31 and the arrangement order thereof, the microphone exhibits excellent sensitivity and capturing ability in processing high-frequency and low-frequency sound waves. The thin film sheet optimizes the capturing of high-frequency sound, the thick film sheet enhances the response to low-frequency sound waves, and the gradual change thickness design not only improves the reduction degree of sound, but also increases the sound capturing range of the microphone, so that a user is ensured to obtain more comprehensive and real sound experience.

The above embodiments are not intended to limit the scope of the present application, so: all equivalent changes in structure, shape and principle of the application should be covered in the scope of protection of the application.

Claims (10)

1. An electret microphone, comprising:

-a housing (1), the housing (1) being for carrying and protecting a circuit element;

a back plate (2), the back plate (2) being arranged within the housing (1) and being coated with electret material;

A vibration assembly (3), the vibration assembly (3) comprising a plurality of layers of vibration diaphragms (31) arranged in the housing (1) and arranged opposite to the back plate (2);

The elastic sheet (4) is positioned between the back plate (2) and the vibration component (3), one end of the elastic sheet (4) is fixed on the shell (1), and the other end of the elastic sheet is in abutting connection with the vibration component (3);

And the circuit board (5) is electrically connected with the backboard (2) and the vibration component (3) and is used for a signal amplifying and processing circuit.

2. An electret microphone according to claim 1, characterized in that the vibrating diaphragms (31) are coupled with an acoustically transparent layer (32).

3. An electret microphone according to claim 2, characterized in that an adjusting structure is arranged between the vibrating diaphragms (31) for adjusting the degree of coupling between the vibrating diaphragms (31).

4. An electret microphone according to claim 3, characterized in that the adjustment structure comprises at least one layer (33) of piezoelectric material, which layer (33) of piezoelectric material is arranged in the acoustically transparent layer (32) and changes in thickness in response to an electrical signal.

5. An electret microphone according to claim 4, characterized in that the circuit board (5) is provided with a feedback system which adjusts the layer (33) of piezoelectric material based on microphone output.

6. An electret microphone according to claim 1, characterized in that the vibrating diaphragms (31) are each made of materials of different acoustic properties, having different frequency response intervals.

7. An electret microphone according to claim 6, characterized in that a damping layer (34) is arranged between the vibrating diaphragm (31) and the housing (1).

8. An electret microphone according to claim 7, characterized in that the thickness of each layer of the vibrating diaphragm (31) differs, and the thickness gradually increases from the sound source side to the back plate (2) side.

9. An electret microphone according to claim 1, characterized in that the housing (1) has a double-layer structure with an air layer or a sound-absorbing material sandwiched therebetween.

10. An electret microphone according to claim 9, characterized in that the side of the housing (1) close to the vibrating assembly (3) is provided with an acoustic hole (11) for capturing sound from a desired direction.