A self-calibrating outdoor condenser microphone

Abstract

A self-calibrating outdoor condenser microphone disclosed in the present invention comprises an outer protective cover, a microphone unit detachably mounted in the outer protective cover, and an electrostatic excitation unit fixedly mounted in the outer protective cover, wherein the microphone unit comprises a condenser microphone, the condenser microphone comprises a microphone diaphragm, a metal protective cover is provided on the microphone diaphragm, and one end of the electrostatic excitation unit abuts against the metal protective cover. A self-calibrating outdoor condenser microphone disclosed in the present invention integrates a detachable electrostatic excitation calibration function, which can not only complete electrostatic excitation calibration, but also conveniently and quickly perform sound calibration using a standard sound calibrator.

Description

Technical Field

[0001] The invention relates to the field of environmental monitoring acoustic equipment, and in particular to a self-calibration outdoor condenser microphone. Background Art

[0002] An outdoor microphone is an acoustic device commonly used for environmental noise monitoring, usually consisting of a working standard condenser microphone and a specially designed outdoor kit. As the outdoor environment is complex and changeable, and condenser microphones are precision instruments and equipment, when outdoor microphones are used for long-term, all-weather monitoring tasks, in addition to being waterproof, windproof, and dustproof, they must also be able to perform daily inspections on the microphones to detect whether the microphones have sensitivity fluctuations due to long-term operation or environmental changes, so that users can correct the correction coefficients in a timely manner to avoid deviations in noise monitoring results.

[0003] Capacitive sensor calibration is usually divided into two methods: acoustic signal calibration and electrostatic excitation calibration. Acoustic signal calibration requires placing a standard acoustic calibrator on the microphone. The calibrator emits a standard single-frequency acoustic signal as a calibration reference. Since the standard acoustic calibrator is only applicable to laboratory standard microphones, if the acoustic calibration method is used for daily detection of outdoor microphones, it needs to be frequently disassembled and assembled. Therefore, in order to facilitate long-term monitoring of environmental noise, the daily inspection of outdoor microphones mainly uses the electrostatic excitation calibration method. The principle is to transmit an electrical signal of known frequency and amplitude directly to the microphone diaphragm through an electrostatic excitation device to stimulate the microphone response, and then compare the original electrical signal and the microphone response. If the microphone response deviation exceeds the set value, the user is prompted to use the acoustic signal calibrator to adjust the correction coefficient of the outdoor microphone system. In summary, outdoor microphones suitable for long-term monitoring of environmental noise should not only have the function of daily detection and calibration of electrostatic excitation, but also be able to use standard acoustic calibrators for acoustic calibration conveniently and quickly.

[0004] Based on the above requirements, existing outdoor microphone products with electrostatic excitation calibration function have the following defects:

[0005] (1) Outdoor microphones with electrostatic excitation calibration are usually equipped with an electrostatic excitation adapter on the condenser microphone, and the microphone diaphragm must be exposed to the electrostatic excitation device without the protective cover. Therefore. When sound calibration is required, the outdoor protection kit and adapter must be removed first, and the microphone protective cover must be installed before the standard sound calibrator can be installed. The operation is cumbersome and it is easy to introduce manual installation errors or damage the precision parts of the microphone due to improper operation.

[0006] (2) Some improved outdoor microphones with electrostatic excitation calibration function are designed by integrating the electrostatic excitation device and the condenser microphone. When calibrating the sound signal, the electrostatic excitation device can be directly installed in the standard sound calibrator without removing the electrostatic device. However, the electrostatic excitation kit of these products has a complex structure, which increases the size of the outdoor microphone. In order to adapt to the specifications of the sound calibrator, the outdoor microphone with the kit is usually as large as a 1 / 2-inch condenser microphone. The condenser microphone installed in the kit can only be reduced in size or specially designed. This not only sacrifices the acoustic performance of the outdoor microphone, but is also not conducive to mass production. Summary of the invention

[0007] The purpose of the present invention is to provide a self-calibrating outdoor condenser microphone, which integrates a detachable electrostatic excitation calibration function, and can not only complete the electrostatic excitation calibration, but also conveniently and quickly use a standard sound calibrator for sound calibration.

[0008] In order to solve the above technical problems, the technical solution of the present invention is:

[0009] A self-calibration outdoor condenser microphone comprises an outer protective cover, a microphone unit detachably mounted in the outer protective cover, and an electrostatic excitation unit fixedly mounted in the outer protective cover, wherein the microphone unit comprises a condenser microphone, the condenser microphone comprises a microphone diaphragm, a metal protective cover is provided on the microphone diaphragm, and one end of the electrostatic excitation unit abuts against the metal protective cover.

[0010] Preferably, the electrostatic excitation unit comprises an electrostatic exciter and a conductive ejector, one end of the conductive ejector is connected to the electrostatic exciter via a spring, and the other end of the conductive ejector is in contact with the metal protective cover.

[0011] Preferably, the metal protective cover comprises a protective cover shell threadedly connected to the condenser microphone, a metal end cover covered on the protective cover shell, and an insulating pad arranged between the protective cover shell and the metal end cover.

[0012] Preferably, a plurality of through holes are formed on the metal end cover, and the other end of the conductive ejector pin abuts against the through hole in the center of the metal end cover.

[0013] Preferably, the electrostatic excitation unit further comprises a first control circuit electrically connected to the electrostatic actuator, and the first control circuit controls the signal frequency, signal amplitude and calibration times of the self-calibration of the microphone unit.

[0014] Preferably, the self-calibration outdoor condenser microphone further comprises a handle threadedly connected to one end of the outer protective cover, and the first control circuit is disposed in the handle.

[0015] Preferably, the microphone unit further comprises a preamplifier connected to the condenser microphone, and a temperature and humidity monitoring unit is installed on the preamplifier.

[0016] Preferably, the temperature and humidity monitoring unit comprises a temperature and humidity sensor mounted on the preamplifier and an electric heating film wrapped around the preamplifier.

[0017] Preferably, the temperature and humidity monitoring unit further comprises a second control circuit electrically connected to the temperature and humidity sensor and the electric heating film, wherein the second control circuit collects monitoring data of the temperature and humidity sensor and controls the start and stop of the electric heating film.

[0018] Preferably, the self-calibration outdoor condenser microphone further comprises a handle threadedly connected to one end of the outer protective cover, and the second control circuit is disposed in the handle.

[0019] Preferably, a microphone socket is provided in the handle, and the microphone unit is fixedly installed in the microphone socket.

[0020] Preferably, a transfer hole is provided on the tail end surface of the handle.

[0021] Preferably, the self-calibration outdoor condenser microphone further comprises a wind ball completely sleeved outside the outer protective cover, the outer surface of the wind ball is provided with a circle of positioning grooves, and the positioning grooves are arranged corresponding to the microphone diaphragm.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] (1) The electrostatic excitation unit is integrated into an outer protective cover that is detachably connected to the microphone unit, and a metal protective cover is provided on the microphone diaphragm of the condenser microphone. One end of the electrostatic excitation unit is abutted against the metal protective cover, so that the self-calibration outdoor condenser microphone can complete the electrostatic excitation calibration without removing the electrostatic excitation unit. The electrostatic excitation unit can also be quickly removed, which is convenient for using a standard sound calibrator for sound calibration.

[0024] (2) The metal protective cover is always placed on the microphone diaphragm and has the functions of an electrostatic excitation calibration conductive plate and a microphone diaphragm protective cover. Therefore, the condenser microphone used can be a common laboratory standard 1 / 2-inch microphone, which simplifies the production process and allows for quick and convenient maintenance of outdoor microphones during long-term outdoor noise monitoring work.

[0025] (3) Equipped with a temperature and humidity monitoring unit, it can automatically detect low temperature and high humidity environments and turn on the heating function to prevent the calibration system from failing in high humidity environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are only for explanation purposes and are not intended to limit the scope of the present invention in any way. In addition, the shapes and proportional dimensions of the components in the drawings are only for illustration purposes and are used to help understand the present invention. They do not specifically limit the shapes and proportional dimensions of the components of the present invention. Under the guidance of the present invention, those skilled in the art can select various possible shapes and proportional dimensions to implement the present invention according to specific circumstances. In the drawings:

[0027] Figure 1 It is a structural schematic diagram of a self-calibration outdoor condenser microphone of the present invention;

[0028] Figure 2 It is a schematic structural diagram of a microphone unit and an electrostatic excitation unit in the present invention;

[0029] Figure 3 It is a schematic diagram of the structure of the metal protective cover in the present invention;

[0030] Figure 4 It is a schematic diagram of the structure of the outer protective cover in the present invention;

[0031] Figure 5 It is a structural schematic diagram of the temperature and humidity monitoring unit in the present invention;

[0032] Figure 6 It is a structural schematic diagram of the handle in the present invention;

[0033] Figure 7 It is a schematic diagram of the structure of the bird-proof frame and the wind ball in the present invention;

[0034] As shown in the figure:

[0035] 1. Outer protective cover; 11. Hollow grid; 111. Sound-transmitting window; 112. Inclined platform; 2. Handle; 21. Adapter hole; 3. Bird-proof frame; 31. Anti-loosening barb; 32. Limiting step; 4. Wind ball; 41. Positioning groove; 5. Microphone unit; 51. Capacitor microphone; 511. Microphone diaphragm; 52. Preamplifier; 6. Electrostatic excitation unit; 61. Electrostatic exciter; 62. Conductive ejector pin; 63. First control circuit; 64. Electrostatic signal transmission line; 7. Metal protective cover; 71. Protective cover shell; 72. Metal end cap; 721. Through hole; 73. Insulating pad; 8. Temperature and humidity monitoring unit; 81. Temperature and humidity sensor; 82. Electric heating film; 83. Second control circuit. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0037] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only embodiment.

[0038] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0039] like Figure 1 and Figure 2 As shown, a self-calibration outdoor condenser microphone corresponding to a preferred embodiment of the present invention comprises an outer protective cover 1, a handle 2 threadedly connected to one end of the outer protective cover 1, a bird-proof frame 3 threadedly connected to the other end of the outer protective cover 1, and a wind ball 4 completely sleeved outside the outer protective cover 1. A microphone unit 5 and an electrostatic excitation unit 6 are detachably installed in the outer protective cover 1, and the microphone unit 5 comprises a condenser microphone 51, and the condenser microphone 51 comprises a microphone diaphragm 511, and a metal protective cover 7 is provided on the microphone diaphragm 511, and one end of the electrostatic excitation unit 6 abuts against the metal protective cover 7.

[0040] like Figure 2 and Figure 6As shown, the electrostatic excitation unit 6 includes an electrostatic exciter 61, a conductive ejector pin 62 and a first control circuit 63. In the present embodiment, the electrostatic exciter 61 is fixedly mounted on the upper end of the outer protective cover 1, one end of the conductive ejector pin 62 is connected to the output end of the electrostatic exciter 61 through a spring, and the other end is abutted against the metal protective cover 7. Under normal installation conditions, the spring is in a compressed state, and the reaction force of the spring can press the conductive ejector pin 62 toward the metal protective cover 7 to prevent the ejector pin from loosening. The first control circuit 63 is electrically connected to the electrostatic exciter 61 to control the signal frequency, signal amplitude and calibration times of the self-calibration of the microphone unit 5. Preferably, a hole is opened on one side of the upper end of the outer protective cover 1 for inserting an electrostatic signal transmission line 64 connected between the first control circuit 63 and the electrostatic exciter 61, and the first control circuit 63 is arranged in the handle 2.

[0041] like Figure 2 and Figure 4 As shown, the outer protective cover 1 is a conical structure that is narrow at the top and wide at the bottom, and a plurality of hollow grids 11 are arranged at intervals on the side wall at the end. When the electrostatic signal transmission line 64 is installed, it is placed close to the surface of one of the hollow grids 11 to minimize the influence of the transmission line on the sound field. The hollow grid 11 includes a sound-transmitting window 111 and a ramp 112 located below the sound-transmitting window 111. The sound-transmitting window 111 is preferably a columnar structure, and the ramp 112 is preferably smooth inside and outside, with an inclination angle of about 75° relative to the horizontal plane. The inner surface of the ramp 112 is tightly matched with the outer wall of the condenser microphone 51, so that the condenser microphone 51 will not shake in the outer protective cover 1, and the microphone diaphragm 511 is installed at the sound-transmitting window 111 to facilitate sound pickup.

[0042] like Figure 3 As shown, the metal protective cover 7 includes a protective cover shell 71 threadedly connected to the capacitor microphone 51, a metal end cap 72 covered on the protective cover shell 71, and an insulating pad 73 arranged between the protective cover shell 71 and the metal end cap 72. The metal end cap 72 is made of conductive metal material, and a plurality of through holes 721 with the functions of sound transmission and reducing acoustic resistance are opened on the surface. The other end of the conductive ejector pin 62 abuts against the through hole 721 in the center of the metal end cap 72. Preferably, the other end of the conductive ejector pin 62 is hemispherical, and the diameter is slightly larger than the through hole, so that the two are not easy to fall off when abutting. The metal end cap 72 can be used as a conductive plate to excite the vibration of the microphone diaphragm 511 in the electrostatic excitation calibration, and plays a role in protecting the microphone diaphragm 511 in the sound signal calibration and daily monitoring. The insulating pad 73 is arranged below the metal end cap 72, and can prevent the metal end cap 72 from contacting the microphone diaphragm 511 when in use. The protective cover shell 71 is preferably made of stainless steel and has an internal thread therein, which can be screwed together with an external thread disposed below the microphone diaphragm 511 .

[0043] like Figure 5 and Figure 6 As shown, the microphone unit 5 also includes a preamplifier 52 connected to the condenser microphone 51, and a temperature and humidity monitoring unit 8 is installed on the preamplifier 52. The temperature and humidity monitoring unit 8 includes a temperature and humidity sensor 81 installed on the preamplifier 52, an electric heating film 82 wrapped outside the preamplifier 52, and a second control circuit 83 electrically connected to the temperature and humidity sensor 81 and the electric heating film 82. In this embodiment, the temperature and humidity sensor 81 is preferably pasted on the tail of the preamplifier 52, and the electric heating film 82 is wrapped along the outer wall of the preamplifier 52. The upper edge is close to the connection edge of the condenser microphone 51 and the preamplifier 52, and the length is preferably 30mm. The second control circuit 83 is arranged in the handle 2 to collect the monitoring data of the temperature and humidity sensor 81 and control the start and stop of the electric heating film. During operation, the temperature and humidity sensor 81 detects the temperature and humidity of the air in real time. When the temperature is lower than the set value or the humidity is higher than the set value, the second control circuit controls the electric heating film 82 to start the heating function. Since the preamplifier 52, the housing of the condenser microphone 51, and the microphone diaphragm 511 are all made of metal materials, the microphone diaphragm 511 can be heated and dried by heat conduction.

[0044] A microphone socket (not shown) is provided in the handle, and the microphone unit 5 is fixedly installed in the microphone socket. Preferably, when the preamplifier 52 is installed in the microphone socket, the microphone diaphragm 511 of the capacitor microphone 51 is located approximately in the middle of the area surrounded by the sound-transmitting window 111.

[0045] The end surface of the handle 2 is provided with an adapter hole 21. The signal output line of the condenser microphone 51 and the control line of the external device pass through the adapter hole 21. In addition, according to the needs, threaded adapters of different specifications can be installed on the adapter hole 21 to connect the extension rod, so as to facilitate the use of the outdoor microphone in various environmental conditions.

[0046] like Figure 7 As shown, the self-calibration outdoor condenser microphone also includes a wind ball 4 completely mounted outside the outer protective cover 1. The wind ball 4 is a protective component of the outdoor microphone, which is used to prevent wind noise, dust and water. The structure of the wind ball 4 is an elliptical sponge ball with a central hole, and a circle of positioning grooves 41 are provided on its outer surface. When the wind ball 4 is installed, the positioning grooves 41 are correspondingly arranged with the microphone diaphragm 511, which is convenient for users to accurately collect noise.

[0047] The bird-proof frame 3 is provided with anti-loosening barbs 31 and limiting steps 32 to fix the wind ball 4. The wind ball 4 is partially mounted on the bird-proof frame 3 and fixed by the anti-loosening barbs 31. The top of the wind ball 4 abuts against the limiting step 32 to ensure that the wind ball 4 can completely cover the outer protective cover 1. At this time, the position of the positioning groove 41 is near the plane of the microphone diaphragm 511, which is convenient for users to accurately collect noise.

[0048] The condenser microphone 51 used in this embodiment is a 1 / 2 inch condenser microphone, and the first control circuit 63 and the second control circuit 83 can be integrated into a unified circuit.

[0049] The self-calibration outdoor condenser microphone assembly process of the present invention includes:

[0050] Before assembly, the first control circuit 63, the second control circuit 83 and the microphone socket are pre-installed in the handle, the electrostatic excitation unit 6 is pre-installed in the outer protective cover 1, and the electrostatic signal transmission line 64 is fixed to one of the grid surfaces of the side wall of the outer protective cover 1.

[0051] During assembly, first, a metal protective net is put on the outer protective cover 1. The protective net should cover all the hollow grids 11 and expose the threaded joint on the top of the outer protective cover 1.

[0052] Secondly, screw the threaded joint of the outer protective cover into the bottom of the bird-proof frame, while pressing the metal protective net tightly;

[0053] Glue the temperature and humidity sensor 81 and the electric heating film 82 to the outer wall of the preamplifier 52 of the microphone unit 5, with the temperature and humidity sensor 81 glued near the tail joint, and the upper edge of the electric heating film 82 close to the joint between the preamplifier 52 and the capacitor microphone 51, and then insert the microphone unit 5 into the microphone socket reserved in the handle 2;

[0054] Remove the original protective cover of the condenser microphone, install the metal protective cover 7 and tighten it;

[0055] Install the condenser microphone 51 into the assembled outer protective cover 1. Observe through the hollow grid 11 whether the conductive pin 62 is pressed against the metal protective cover 7. After confirmation, tighten the bottom thread of the outer protective cover.

[0056] Finally, insert the wind ball 4 from the tip of the bird-proof frame, and gently drag the wind ball 4 toward the handle 2 until the limiting step 32 on the bird-proof frame 3 is exposed. At this time, the positioning groove 41 on the wind ball is located near the plane of the microphone diaphragm 511.

[0057] When the self-calibration outdoor capacitor microphone of the present invention is calibrated by electrostatic excitation, the metal end cap 72 serves as a conductive plate to excite the vibration of the microphone diaphragm 511, and forms a capacitor with the microphone diaphragm 511. After voltage is applied to the metal end cap 72, an electrostatic force F is generated on the microphone diaphragm 511, and F causes the microphone diaphragm 511 to vibrate, similar to the vibration generated by the microphone under the action of sound pressure. The working voltage of the electrostatic actuator 61 only uses AC voltage, measures the instantaneous excitation sound pressure of the microphone diaphragm 511, and compares it with the amplitude of the original excitation signal to calculate the error value and determine whether the error exceeds the set value. If it exceeds the tolerance, the user is prompted that the outdoor microphone needs maintenance. The advantages of using AC voltage as the calibration signal here include: 1. The excitation power module is small in size and suitable for handheld outdoor microphones; 2. The use of direct current requires a high voltage of hundreds of volts to excite sufficient instantaneous sound pressure. In a high-humidity environment, the high voltage is easy to break through the microphone diaphragm and damage the equipment.

[0058] When signal calibration is required, it is only necessary to remove the outer protective cover 1 to expose the condenser microphone 51, and directly install the condenser microphone 51 into the standard sound calibrator, which greatly simplifies the operation steps. At this time, the metal protective cover 7 is still installed on the microphone diaphragm 511. When the outer protective cover 1 is installed again, the distance between the electrostatic actuator 61 and the microphone diaphragm 511 is always consistent, avoiding the operation error introduced by the repeated disassembly and assembly in the traditional electrostatic excitation calibration; in daily noise monitoring work, the metal protective cover 7 also plays a role in dust prevention.

[0059] It should be understood that the above description is for illustration and not for limitation. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but rather with reference to the foregoing claims and the full scope of equivalents to which such claims are entitled. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended to be a waiver of such subject matter, nor should it be considered that the applicant has not considered such subject matter to be part of the disclosed inventive subject matter.

Claims

1. A self-calibrating outdoor condenser microphone, characterized in that: The device comprises an outer protective cover, a microphone unit detachably mounted in the outer protective cover, and an electrostatic excitation unit fixedly mounted in the outer protective cover, wherein the microphone unit comprises a condenser microphone, the condenser microphone comprises a microphone diaphragm, a metal protective cover is provided on the microphone diaphragm, and one end of the electrostatic excitation unit abuts against the metal protective cover; The electrostatic excitation unit includes an electrostatic exciter and a conductive ejector, one end of the conductive ejector is connected to the electrostatic exciter through a spring, and the other end is in contact with the metal protective cover; the metal protective cover includes a protective cover shell threadedly connected to the condenser microphone, a metal end cover covered on the protective cover shell, and an insulating pad arranged between the protective cover shell and the metal end cover; The electrostatic excitation unit further includes a first control circuit electrically connected to the electrostatic actuator, and the first control circuit controls the signal frequency, signal amplitude and calibration times of the self-calibration of the microphone unit.

2. The self-calibrating outdoor condenser microphone according to claim 1, characterized in that: The metal end cover is provided with a plurality of through holes, and the other end of the conductive ejector pin abuts against the through hole in the center of the metal end cover.

3. The self-calibrating outdoor condenser microphone according to claim 1, characterized in that: The self-calibration outdoor condenser microphone further comprises a handle threadedly connected to one end of the outer protective cover, and the first control circuit is arranged in the handle.

4. The self-calibrating outdoor condenser microphone according to claim 1, characterized in that: The microphone unit also includes a preamplifier connected to the capacitor microphone, and a temperature and humidity monitoring unit is installed on the preamplifier.

5. The self-calibrating outdoor condenser microphone according to claim 4, characterized in that: The temperature and humidity monitoring unit includes a temperature and humidity sensor installed on the preamplifier and an electric heating film wrapped outside the preamplifier.

6. The self-calibrating outdoor condenser microphone according to claim 5, characterized in that: The temperature and humidity monitoring unit also includes a second control circuit electrically connected to the temperature and humidity sensor and the electric heating film. The second control circuit collects monitoring data of the temperature and humidity sensor and controls the start and stop of the electric heating film.

7. The self-calibrating outdoor condenser microphone according to claim 6, characterized in that: The self-calibration outdoor condenser microphone further comprises a handle threadedly connected to one end of the outer protective cover, and the second control circuit is arranged in the handle.

8. The self-calibrating outdoor condenser microphone according to claim 3 or 7, characterized in that: A microphone socket is arranged in the handle, and the microphone unit is fixedly installed in the microphone socket.

9. The self-calibrating outdoor condenser microphone according to claim 3 or 7, characterized in that: The tail end surface of the handle is provided with a transfer hole.

10. The self-calibrating outdoor condenser microphone according to claim 1, characterized in that: The self-calibration outdoor condenser microphone also includes a wind ball completely sleeved outside the outer protective cover, and a circle of positioning grooves is arranged on the outer surface of the wind ball, and the positioning grooves are arranged corresponding to the microphone diaphragm.

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