WO2023272496A1 - 录音传声器后极板及录音传声器 - Google Patents

录音传声器后极板及录音传声器 Download PDF

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WO2023272496A1
WO2023272496A1 PCT/CN2021/103174 CN2021103174W WO2023272496A1 WO 2023272496 A1 WO2023272496 A1 WO 2023272496A1 CN 2021103174 W CN2021103174 W CN 2021103174W WO 2023272496 A1 WO2023272496 A1 WO 2023272496A1
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Prior art keywords
diaphragm
recording microphone
rear plate
spherical surface
microphone
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PCT/CN2021/103174
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English (en)
French (fr)
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乔琼
王鹏
李亮
吕兆明
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九声(唐山)科技有限公司
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Priority to PCT/CN2021/103174 priority Critical patent/WO2023272496A1/zh
Priority to DE112021000019.5T priority patent/DE112021000019T5/de
Priority to US17/395,447 priority patent/US11877137B2/en
Publication of WO2023272496A1 publication Critical patent/WO2023272496A1/zh

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R19/00—Electrostatic transducers
    • H04R19/04—Microphones
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R9/00—Transducers of moving-coil, moving-strip, or moving-wire type
    • H04R9/08—Microphones
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R31/00—Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R7/00—Diaphragms for electromechanical transducers; Cones
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R31/00—Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor
    • H04R31/003—Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor for diaphragms or their outer suspension

Definitions

  • the present application relates to the technical field of acoustic-electric conversion, in particular to a rear plate of a recording microphone and the recording microphone.
  • Microphones are essential input devices in electroacoustic systems. According to different application scenarios, microphones can be divided into recording microphones and measurement microphones. Among them, the recording microphone is mainly used to record music, human voice, etc., which is fundamentally different from the measurement microphone. "The main function of the sound is not to restore the original sound as real as possible.
  • a condenser microphone is a microphone that can be used in recording scenes, and it includes two plates, one of which is a diaphragm, and the other is a rear plate.
  • the diaphragm When the sound signal acts on the diaphragm, the diaphragm is forced to vibrate, thereby changing the distance between the diaphragm and the rear plate, causing the capacitance between the two plates to change, and the effect of the polarization circuit will be The sound signal is converted into an electrical signal.
  • the diaphragm when the diaphragm is in a static state, the diaphragm is parallel to the surface of the rear plate facing the diaphragm, and when a loud sound signal acts on the diaphragm, under the action of the polarization voltage, The diaphragm moves towards the rear plate, and the two are infinitely close to each other, so they are easily adsorbed together, causing the microphone to be inactive for a moment.
  • the application provides a recording microphone rear plate and the recording microphone.
  • the rear plate of a recording microphone provided by the application adopts the following technical scheme:
  • a rear pole plate of a recording microphone the surface of the rear pole plate facing the diaphragm is a spherical surface sunken away from the diaphragm.
  • the membrane suction voltage of the recording microphone can be increased, and the occurrence of adsorption of the membrane to the rear plate under the action of a sound signal at a loud pressure level can be reduced.
  • chord length of the spherical surface is equal to the diameter of the vibration range of the diaphragm
  • the maximum depth at the center of the spherical surface is greater than or equal to the maximum amplitude at the center of the diaphragm.
  • the suction membrane voltage of the recording microphone can be increased and the sound quality can be improved.
  • the spherical surface is formed by laser processing.
  • a recording microphone provided by the application adopts the following technical solution:
  • a recording microphone comprising the aforementioned recording microphone rear plate and a diaphragm located on one side of the spherical surface of the rear plate.
  • the rear plate of the recording microphone and the recording microphone provided by this application can effectively improve the maximum sound pressure level that the recording microphone can withstand, and reduce the occurrence of adsorption of the diaphragm to the rear plate under the action of the sound pressure level signal .
  • Fig. 1 is a schematic diagram of the structure of the rear plate and the positional relationship between the diaphragm and the rear plate;
  • Figure 2 is a schematic diagram of the ideal vibration mode of the diaphragm.
  • the embodiment of the present application discloses a rear plate of a recording microphone, and the rear plate is made of metal materials such as copper in the related art. Since the diaphragm can be idealized into a parabolic shape during the vibration process, the surface of the rear plate facing the diaphragm can be set as a spherical surface concave away from the diaphragm, so as to provide a certain vibration gap and reduce the vibration of the diaphragm. Adsorption with the rear plate occurs.
  • the spherical surface can be processed by laser processing and other processes, so as to ensure that the spherical surface has good processing accuracy.
  • the chord length L of the spherical surface is set to be twice the radius R 1 of the rear plate.
  • the radius R1 of the rear plate is set to be equal to the radius R2 of the vibration region of the diaphragm.
  • the maximum depth of the center of the spherical surface is determined in the following way:
  • T is the edge tension of the diaphragm
  • ⁇ is the angle between the edge tension T and the diameter of the diaphragm at rest.
  • the restoring force F 1 and the edge tension T of the diaphragm at the maximum amplitude can be calculated.
  • the maximum amplitude of the diaphragm is:
  • the maximum depth H of the center of the spherical surface is set to be greater than or equal to the maximum amplitude u of the diaphragm, and the maximum amplitude u of the diaphragm is related to the sound pressure level of the application scene of the recording microphone. According to the characteristics of the recording microphone, as the depth of the spherical surface increases, the capacitance between the diaphragm and the rear plate when it vibrates under the condition of a large sound pressure level increases accordingly, so that the sensitivity of the microphone increases accordingly.
  • the maximum central amplitude of the diaphragm under the forced vibration of a large sound pressure level signal at a certain resonant frequency is 45 ⁇ m.
  • the maximum depth H of the center of the spherical surface is 45 ⁇ m, the center of the diaphragm is just parallel to the spherical surface when it reaches the maximum amplitude. gap, thereby reducing the occurrence of adsorption between the diaphragm and the rear plate.
  • a recording microphone with a traditional structure in order to enable the diaphragm to vibrate freely, it is usually necessary to set a 40-45 ⁇ m thick polyester gasket between the rear plate and the diaphragm.
  • the spherical surface is directly processed on the rear plate through laser processing technology, thereby eliminating the need to use gaskets, simplifying the overall structure of the recording microphone and improving assembly efficiency.
  • the processing accuracy of the gasket is generally 45 ⁇ 2 ⁇ m, while the processing accuracy of the spherical surface formed by the laser processing technology can reach 45 ⁇ 0.5 ⁇ m, which can improve the output of the recording microphone of the same product. Consistency, and can improve the stability of the output of the recording microphone and improve the sound quality.
  • Table 1 shows the corresponding suction film voltage data obtained under the same signal-to-noise ratio and different resonance frequency conditions when the maximum depth of the center of the spherical surface is 45 ⁇ m.
  • Table 1 The test data of the suction membrane voltage of the spherical rear pole recording microphone
  • test data of the film suction voltage and release voltage are:
  • the present application also discloses a recording microphone, which adopts the aforementioned rear plate with a spherical surface, and a diaphragm is arranged on one side of the spherical surface of the rear plate.
  • the rear plate of the recording microphone provided by this application, by setting the surface close to the diaphragm as a spherical surface, improves the membrane suction voltage of the recording microphone, and can reduce the contact between the diaphragm and the rear substrate of the recording microphone under the action of the sound pressure level signal. Adsorption leads to inanimate situations.
  • the recording microphone adopting the rear plate of the present application has the advantages of low equivalent noise level and good sound quality.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Manufacturing & Machinery (AREA)
  • Electrostatic, Electromagnetic, Magneto- Strictive, And Variable-Resistance Transducers (AREA)

Abstract

本申请涉及一种传声器后极板及录音传声器，属于声电转换领域，该后极板朝向膜片的表面为向远离膜片的方向凹陷的球形面。本申请提供的录音传声器后极板及录音传声器，能够有效提升录音传声器的可承受最大声压级，减少膜片在大声压级信号的作用下与后极板吸附的情况发生。

Description

录音传声器后极板及录音传声器 技术领域
本申请涉及声电转换技术领域，尤其涉及一种录音传声器后极板及录音传声器。
背景技术
传声器是电声系统中必不可少的输入设备，根据应用场景的不同，传声器可分为录音传声器和测量传声器。其中，录音传声器是主要用于录制音乐、人声等，其与测量传声器的用途有着本质性的差别，测量的目的是真实的还原事物本身的属性，而录音传声器则向用户提供“悦耳、动听”的声音，其主要作用并不是越真实的还原原声越好。
电容传声器是一种可用于录音场景的传声器，其包括两个极板，其中一个极板为膜片，另外一个极板为后极板。当声音信号作用于膜片上时，膜片发生受迫振动，从而改变膜片与后极板之间的距离，引起两个极板之间的电容发生变化，在极化电路的作用，将声音信号转化为电信号。在相关技术的电容传声器中，当膜片处于静止状态时，膜片与后极板朝向膜片的表面相平行，当大声压声音信号作用于膜片上时，在极化电压的作用下，膜片朝向后极板运动，二者无限接近，极易吸附在一起，导致传声器瞬间无灵。
发明内容
为了减少膜片在大声压声音信号的作用下与后极板吸附的情况发生，本申请提供一种录音传声器后极板及录音传声器。
第一方面，本申请提供的一种录音传声器后极板采用如下的技术方案：
一种录音传声器后极板，所述后极板朝向膜片的表面为向远离膜片的方向凹陷的球形面。
通过采用上述技术方案，能够提高录音传声器的吸膜电压，减少膜片在大声压级声音信号的作用下与后极板吸附的情况发生。
可选的，所述球形面的弦长与膜片振动范围的直径相等；
所述球形面的中心最大深度大于等于膜片中心的最大振幅。
通过采用上述技术方案，能够提高录音传声器的吸膜电压并提高音质。
可选的，所述球形面采用激光加工工艺形成。
通过采用上述技术方案，能够提高球形面的加工高精度。
第二方面，本申请提供的一种录音传声器采用如下的技术方案：
一种录音传声器，包括前述的录音传声器后极板以及位于后极板的球形面一侧的膜片。
综上所述，本申请提供的录音传声器后极板及录音传声器，能够有效提升录音传声器的可承受最大声压级，减少膜片在大声压级信号的作用下与后极板吸附的情况发生。
附图说明
图1是后极板结构及膜片与后极板位置关系示意图；
图2是膜片理想振动模态示意图。
具体实施方式
以下结合附图1-2对本申请作进一步详细说明。
参照图1，本申请实施例公开了一种录音传声器后极板，后极板采用相关技术中已有的铜等金属材料制作。由于膜片在振动过程中可以理想化为抛物线形状，因此，可以将后极板朝向膜片的表面设置为向远离膜片的方向凹陷的球形面，从而为提供一定的振动间隙，降低膜片与后极板吸附的情况发生。球形面可以采用激光加工等工艺进行加工，从而保证球形面具有良好的加工精度。
在本申请中，为了使膜片在振动过程中与球形面具有较好的匹配度，球形面的弦长L设置为后极板的半径R 1的2倍。后极板的半径R 1设置为与膜片的振动区域的半径R 2相等。
在本申请中，球形面的中心最大深度采用以下方式确定：
参照图2，根据膜片的振动模态，在理想情况下，膜片中心离开平衡位置的位移u与膜片振动时的恢复力F 1的关系为：
F 1＝-2πR 2Tsinα
式中，T为膜片的边缘张力，α为边缘张力T与膜片静止时直径的夹角。
由于膜片的振幅为微小振幅，因此有
Figure PCTCN2021103174-appb-000001
则有
Figure PCTCN2021103174-appb-000002
根据录音传声器的性能要求及膜片的材料属性，可计算得到膜片在最大振幅情况下的恢复力F 1以及边缘张力T。由此，膜片的最大振幅为：
Figure PCTCN2021103174-appb-000003
此处，将球形面的中心最大深度H设定为大于等于膜片的最大振幅u，膜片的最大振幅u与录音传声器所应用场景的声压级相关。根据录音传声器的特性，随着球形面的深度增加，膜片处于大声压级条件下发生振动时与后极板之间的电容随之增大，从而使得传声器的灵敏度随之提高。
在本申请中，以膜片的振动范围直径为28mm为例，则有膜片在某一谐振频率的大声压级信号受迫振动下的中心最大振幅为45μm。当球形面的中心最大深度H为45μm时，膜片的中心在达到最大振幅时恰好与球形面相平行，在球形面中心最大深度大于45μm时，膜片在达到最大振幅时与后极板仍然保持间隙，从而降低膜片与后极板吸附的情况发生。
在传统结构的录音传声器中，为了使膜片能够自由振动，通常需要在后极板和膜片之间设置40-45μm厚的聚酯垫片。在本申请中，通过激光加工工艺，直接在后极板上加工出球形面，由此无需使用垫片，简化了录音传声器的整体结构，提高了组装效率。而且，在传统的录音传声器中，垫片的加工精度一般为45±2μm，而通过激光加工工艺形成的球形面的加工精度可以达到45±0.5μm，由此可以提高同种产品录音传声器输出的一致性，并且能够提高录音传声器输出的稳定性，提高音质。
表一为球形面的中心最大深度为45μm时，在相同的信噪比、不同的谐振频率条件下测试得到的对应的吸膜电压数据。
表一球形面后极录音传声器吸膜电压测试数据
谐振频率(Hz) 电容(pF) 吸膜电压(V) 绝缘阻抗(Ω)
900 77.3 115 4.7T
1200 81 135 4.7T
1400 85 135 4.7T
由表一可知，在1200Hz和1400Hz的谐振频率下，吸膜电压达到了135V。
参见表二，在振动范围直径为28mm的情况下，当膜片与普通的平面后极板相配合时，其吸膜电压和释放电压的测试数据为：
表二平面后极板录音传声器吸膜电压和释放电压测试数据
Figure PCTCN2021103174-appb-000004
Figure PCTCN2021103174-appb-000005
通过对比可知，在相同的高声压级信号作用下，采用普通的平面后极板时，吸膜电压最高不超过125V。
参见表三，在膜片振动范围直径为28mm的情况下，膜片与球形面后极板和平面后极板配合时的性能参数对比数据为：
表三球形面后极板与平面后极板录音传声器性能参数对比数据
参数 球形面后极板 平面后极板
极化电压 120V 60V
灵敏度 -23.4dB -32.5dB
噪声 1.8mV/-115.4dB A 1.4mV/-117.4dB A
等效噪声级 2.3dB A 9.4dB A
Max in 3.4V 3.6V
Max out 3.0V 3.2V
放大倍数 0.89 0.89
测试电容 83pF 83pF
通过表三数据对比可知，在录音传声器的其他部件参数不变的情况下，当录音传声器采用球形面后极板时，相比于平面后极板，录音传声器的极化电压由60V提高到120V后，录音传声器不仅未发生吸膜，而且等效噪声级由9.4dB A降低至2.3dB A，有效提高了录音传声器的音质。
本申请还公开一种录音传声器，采用前述的具有球形面的后极板，在后极板的球形面一侧设置有膜片。
本申请提供的录音传声器后极板，通过将靠近膜片一侧的表面设置为球形面，提高了录音传声器的吸膜电压，能够降低录音传声器在大声压级信号的作用下膜片与后基板吸附导致无灵的情况发生。同时，采用本申请后极板的录音传声器具有等效噪声级低、音质好的优点。
以上为本申请的较佳实施例，并非依此限制本申请的保护范围，故：凡依本申 请的结构、形状、原理所做的等效变化，均应涵盖于本申请的保护范围之内。

Claims (4)

  1. 一种录音传声器后极板，其特征在于，所述后极板朝向膜片的表面为向远离膜片的方向凹陷的球形面。
  2. 根据权利要求1所述的录音传声器后极板，其特征在于，所述球形面的弦长与膜片振动范围的直径相等；
    所述球形面的中心最大深度大于等于膜片中心的最大振幅。
  3. 根据权利要求1所述的录音传声器后极板，其特征在于，所述球形面采用激光加工工艺形成。
  4. 一种录音传声器，其特征在于，包括权利要求1-3任一项所述的后极板以及位于后极板的球形面一侧的膜片。
PCT/CN2021/103174 2021-06-29 2021-06-29 录音传声器后极板及录音传声器 WO2023272496A1 (zh)

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DE112021000019.5T DE112021000019T5 (de) 2021-06-29 2021-06-29 Hintere Elektrodenplatte eines Aufnahmemikrofons und Aufnahmemikrofon
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