Microphone

Abstract

To provide a microphone having high waterproofness and water repellency.SOLUTION: A microphone comprises: a contour member 12 having a sound hole; a first mesh 13 made of metallic mesh weaved in a tatami-mat shape, arranged inside the contour member; a spacer 14 having a diameter corresponding to an inner diameter of the contour member, whose first surface contacts the first mesh and which presses the first mesh against the inside of the contour member; a second mesh 15 having water repellency that contacts a second surface of the spacer; and a microphone unit 11 that is stored below the second mesh.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a microphone. [Background technology]

[0002] There are known microphones that are used under conditions where they are exposed to water, such as when they are used outdoors, when they are placed on a desk or the like where drinks or the like may be spilled, or when they are embedded in a desk.

[0003] For example, a microphone has been disclosed in the past that covers a first opening of a housing with a sheet member that is breathable and water-repellent, and has a windscreen on the outside of the housing that has drainage properties (see, for example, Patent Document 1).

[0004] The microphone disclosed in Patent Document 1 was difficult to miniaturize because it required a windscreen. In addition, the windscreen has high water retention and is prone to absorbing water, so once it gets wet, it is difficult to restore its original performance. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2017-55228 A Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a microphone that is highly waterproof and water-repellent. [Means for solving the problem]

[0007] The microphone of the present invention comprises an outer casing member having a sound hole, a first mesh made of woven tatami mat arranged inside the outer casing member, a spacer having a diameter corresponding to the inner diameter of the outer casing member and a first surface abutting the first mesh and pressing the first mesh against the inside of the outer casing member, a water-repellent second mesh abutting a second surface of the spacer, and a microphone unit housed below the second mesh. Effect of the Invention

[0008] According to the present invention, a microphone having high waterproof and water-repellent properties is obtained. [Brief description of the drawings]

[0009] [Figure 1] 1A and 1B are a side view and a cross-sectional view, respectively, showing a first embodiment of a microphone according to the present invention. [Diagram 2] FIG. 2 is a vertical cross-sectional view of the microphone. [Diagram 3] FIG. 2 is an exploded perspective view of the microphone. [Figure 4] 5A and 5B are a side view and a cross-sectional view showing a second embodiment of a microphone according to the present invention. [Diagram 5] FIG. 2 is a vertical cross-sectional view of the microphone. [Figure 6] FIG. 2 is an exploded perspective view of the microphone. [Figure 7] 3 is a partially enlarged perspective view showing an acoustic adjustment member and a microphone unit provided in the microphone, with some members omitted. FIG. [Figure 8] FIG. 2 is an acoustic equivalent circuit diagram of the microphone. [Figure 9] 4 is a graph showing the frequency response characteristics of the microphone. [Figure 10] Graphs showing the frequency response characteristics of microphones in related technology: (a) a microphone with a volume ratio between the front air chamber and the rear air chamber of 1:2.5; (b) a microphone with the volume ratio of 1:3; and (c) a microphone with a volume ratio of 1:3.5. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of a microphone according to the present invention will be described with reference to the drawings. In the following description, the axial direction of the microphone 1 is also referred to as the z direction, and the directions perpendicular to the z direction are also referred to as the x direction and the y direction. The surface facing the +z direction is also referred to as the top surface, and the surface facing the -z direction is also referred to as the bottom surface. Note that the arrangement direction of the microphone is not limited to this direction.

[0011] ●Microphone(1)● As shown in FIG. 1 and FIG. 2, the microphone 1 is a member having a substantially cylindrical shape. The microphone 1 has a unit portion 1a that houses a microphone unit 11 (see FIG. 2) at its upper end. A screw portion 1b is threaded on the outer peripheral surface of the housing 30 below the unit portion 1a of the microphone 1. The microphone 1 is fixed to the installation surface such as a desk or a ceiling by screwing the screw portion 1b into a screw hole provided on the installation surface. A circuit board 40 is disposed inside the housing 30. For example, a FET (Field effect transistor) as an impedance converter, an amplifier circuit, a low-cut circuit, and the like are mounted on the circuit board 40. An output connector 1d (see FIG. 2) is disposed on the bottom surface 1c of the microphone 1. The microphone unit 11 is electrically connected to an external device via the output connector 1d.

[0012] As shown in FIGS. 2 and 3, the unit portion 1a mainly includes a microphone unit 11, an outer casing member 12, a first mesh 13, a spacer 14, a second mesh 15, a cover 16, and a fixing portion 20. As shown in FIG.

[0013] The microphone unit 11 is a member that includes a diaphragm and converts sound waves from the outside of the microphone 1 into electric signals. The microphone unit 11 is a member having a substantially cylindrical shape. In this embodiment, the bottom surface of the microphone unit 11 does not communicate with the outside. In other words, the microphone 1 is omnidirectional. However, the technical scope of the present invention is not limited to this.

[0014] The outer casing member 12 is a member that constitutes the outer casing of the upper surface of the microphone 1, and is a cylindrical member with a bottom having multiple sound holes. The outer casing member 12 is made of, for example, an etched plate or a punched plate with small diameter holes. Instead of this configuration, the outer casing member 12 may be an etched plate provided inside a wire mesh. Also, the outer casing member 12 may have one large hole on the top surface instead of multiple sound holes. A first mesh 13 is pressed against the inner wall of the outer casing member 12.

[0015] The first mesh 13 is a mesh made of metal or resin. The first mesh 13 is woven using a tatami weave. The tatami weave can be, for example, a plain tatami weave or a twill tatami weave. A plain tatami weave wire mesh is a wire mesh woven by enlarging the mesh size of the vertical lines and then successively weaving the horizontal lines into a tightly packed mesh. A twill tatami weave wire mesh is a tatami weave wire mesh with a twill weave structure. The horizontal lines of the twill tatami weave wire mesh are in tight contact with both the front and back of the metal, so the density of the twill tatami weave wire mesh is higher than that of the plain tatami weave wire mesh.

[0016] Tatami weave is a weaving method in which horizontal lines proceed obliquely from the front to the back of adjacent vertical lines with respect to the plane of the wire mesh. Therefore, the air holes do not proceed in a straight line. Therefore, with the first mesh 13 made of Tatami weave, there are no flat openings in the mesh like with plain weave, and liquid passes through the gaps at the intersections of the vertical and horizontal lines. In other words, liquid proceeding from the outside toward the first mesh 13 meanders into the inside. Therefore, with the first mesh 13, the water pressure of liquid from the outside can be reduced.

[0017] Furthermore, the first mesh 13 made of woven wire mesh can be made smaller than a microphone with a urethane windscreen. Furthermore, the first mesh 13 made of woven wire mesh is less likely to get stuck in the mesh and less likely to become clogged than a urethane windscreen, ensuring the performance of the microphone 1. Therefore, the microphone 1 can be used outdoors.

[0018] The first mesh 13 can repel small amounts of liquid or liquids with low water pressure due to surface tension. Therefore, the microphone 1 can easily return to its original state by wiping off water droplets on the surface, such as water spilled from a cup or light rain. In addition, since the first mesh 13 located on the outside is made of metal, the microphone 1 has a lower water retention capacity than a urethane windscreen, and therefore dries easily even when liquid adheres to it. For example, when the microphone 1 is embedded in a desk and only the upper part is exposed to the desk surface, it dries easily and maintains its sound collection performance even if liquid is spilled on the desk.

[0019] The metallic first mesh 13 is more durable than urethane. Therefore, the microphone 1 requires less frequent maintenance and can be easily used even in places that are difficult for workers to reach, such as outdoors or on the ceiling.

[0020] The spacer 14 is a substantially annular member. The spacer 14 has an annular portion 14a, a small annular portion 14b, and a plurality of spokes 14c. The annular portion 14a constitutes the outer periphery of the spacer 14, and the small annular portion 14b is substantially concentric with the annular portion 14a and is disposed within the annular portion 14a. The spokes 14c connect the annular portion 14a and the small annular portion 14b. In other words, the spacer 14 has a plurality of through holes 14d surrounded by the annular portion 14a, the small annular portion 14b, and the plurality of spokes 14c. The annular portion 14a has a rib 14e that protrudes in the thickness direction around the entire circumference of the outer edge.

[0021] The spacer 14 has a diameter that fits inside the outer casing member 12. The spacer 14 is an elastic member formed of, for example, resin. The outer diameter of the annular portion 14a in its natural state is slightly larger than the inner diameter of the outer casing member 12. With this configuration, when the first mesh 13 is pressed into the inside of the outer casing member 12 together with the spacer 14, the spacer 14 expands inside the outer casing member 12. That is, the first surface of the spacer 14 abuts against the first mesh 13 and presses the first mesh 13 into the inside of the outer casing member 12. The first mesh 13 and the spacer 14 are then fixed inside the outer casing member 12.

[0022] The annular portion 14a of the spacer 14 has a pair of recesses 14f facing each other. The recesses 14f are adapted to fit with the protrusions 16e of the cover 16 in an assembled state.

[0023] The cover 16 is a cylindrical member with a bottom having an opening 16a on the bottom side (-z side) of the microphone 1. The cover 16 is made of, for example, resin. The second mesh 15 is fixed to the bottom 16b and the outer peripheral surface 16c of the cover 16. That is, the second surface of the spacer 14 abuts against the second mesh 15 fixed to the bottom 16b.

[0024] The second mesh 15 is a water-repellent mesh made of, for example, plain weave. The second mesh may be made of metal or resin. The second mesh 15 repels liquid entering from the outside and prevents the liquid from entering the inside of the cover 16. The cover 16 has a plurality of holes in the bottom 16b and the outer circumferential surface 16c. External sound reaches the microphone unit 11 through the holes and the second mesh 15.

[0025] In this way, the microphone 1 according to the present invention achieves high waterproofing and water repellency by the first mesh 13 and the second mesh 15, which are woven differently from each other. Specifically, liquid splashed on the microphone 1 is dispersed by the first mesh 13, resulting in a reduction in weight and a reduction in water pressure per unit. The microphone 1 repels this liquid by the second mesh 15, so that the intrusion of the liquid into the inside can be reliably prevented. Furthermore, the outer casing member 12 adjusts the inflow direction of the liquid to a direction perpendicular to the first mesh 13 by the sound hole. In other words, the outer casing member 12 further increases the effect of reducing water pressure by the first mesh 13. Furthermore, the first gap K1 between the first mesh 13 and the second mesh 15 further reduces water pressure, and the second mesh 15 can reliably prevent the intrusion of liquid.

[0026] Here, the first mesh 13 has high acoustic resistance because not only liquid but also gas cannot pass through it in a straight line. Therefore, a configuration for controlling the acoustic resistance value generated by the first mesh 13 and ensuring the characteristics of the microphone 1 will be described below.

[0027] As described above with reference to FIG. 2 and FIG. 3, the spacer 14 is disposed between the first mesh 13 and the second mesh 15. That is, a first gap K1 is formed between the first mesh 13 and the second mesh 15 in the axial direction of the microphone 1. The first gap K1 is formed by the sidewall of the through hole defined by the annular portion 14a, the small annular portion 14b, and the spokes 14c of the spacer 14. A plurality of first gaps K1 are arranged in parallel on the xy plane. In addition, the rib 14e of the annular portion 14a of the spacer 14 presses the first mesh 13 along the curved portion of the outer casing member 12. As a result, a second gap K2 is formed by the rib 14e, the second mesh 15 fixed to the outer peripheral surface 16c of the cover 16, and the inner sidewall of the first annular portion 20a of the fixing portion 20.

[0028] According to the configuration in which the spacer 14 presses the first mesh 13 against the inner wall of the outer casing member 12, the volumes of the first gap K1 and the second gap K2 formed between the first mesh 13 and the second mesh 15 can be made constant. That is, the acoustic resistance value generated by the first mesh 13 becomes approximately constant for each individual unit in mass production, and is maintained over a long period of time. As a result, it is possible to design the microphone 1 taking into consideration the acoustic resistance of the first mesh 13, so that the characteristics of the microphone 1 can be guaranteed while the first mesh 13 with high acoustic resistance is disposed on the outside of the microphone unit 11.

[0029] The outer peripheral surface 16c of the cover 16 has a protrusion 16e protruding in the radial direction. The protrusions 16e are formed in pairs at positions facing each other, and engage with the recesses 14f of the spacer 14. In this embodiment, there are two recesses 14f and two protrusions 16e, but this number is merely an example. The cover 16 also has a rib 16d protruding in the radial direction around the entire circumference at the end of the opening 16a. The rib 16d abuts against the inner wall of a step 20c (see FIG. 2) formed in the fixing portion 20, and the axial position is fixed.

[0030] The unit holding member 17 is a cylindrical member that holds the microphone unit 11 inside. The unit holding member 17 is formed of an elastic member such as elastomer or rubber. As shown in FIG. 2, the unit holding member 17 holds the microphone unit 11 at its upper end and is housed in the upper end of the housing 30. The unit holding member 17 has an outer diameter on the upper surface side that is larger than the outer diameter on the bottom surface side. This difference in outer diameter forms a step 17a that extends over the entire outer periphery. On the other hand, the inner diameter of the upper end of the housing 30 is larger than the inner diameter of the central portion. Due to this difference in inner diameter, a step 30a is formed on the inner wall of the housing 30. The step 17a of the unit holding member 17 abuts against the step 30a.

[0031] The fixing part 20 is an annular member that holds the cover 16. The fixing part 20 has a shape in which a first annular part 20a and a second annular part 20b, which have different diameters, are connected over the entire circumference by a step part 20c. The first annular part 20a has a larger inner diameter than the second annular part 20b. The outer casing member 12 is fitted inside the first annular part 20a. The first annular part 20a and the outer casing member 12 integrally hold the first mesh 13, the spacer 14, and the second mesh 15. The upper end of the housing 30 is inserted into the second annular part 20b, and the second annular part 20b and the housing 30 are connected to each other. The manner of connection can be appropriately selected, but the second annular part 20b and the housing 30 may be connected to each other by a screw that is inserted into a small hole 20d of the second annular part 20b and a hole in the housing 30, for example.

[0032] In this way, the microphone 1 according to the present invention can achieve high waterproof and water repellency.

[0033] ●Microphone(2)● The second embodiment of the microphone according to the present invention will be described, focusing on the differences from the first embodiment. The microphone according to the second embodiment differs from the first embodiment in that the front and rear sides of the microphone unit are open and configured as a directional microphone. In the following figures, the same reference numerals are used for the same components as the first embodiment.

[0034] 5 and 6, in this embodiment, microphone unit 11 is held in a direction (x direction in the drawings) substantially perpendicular to the axial direction of microphone 101. Microphone unit 11 is held by acoustic adjustment member 50. Front surface 11a and rear surface 11b of microphone unit 11 each serve as a sound collecting surface.

[0035] The acoustic adjustment member 50 is a member that holds the microphone unit 11 and is connected to the housing 30. The acoustic adjustment member 50 may be made of an elastic material. For example, the acoustic adjustment member 50 is made of an elastomer or a rubber molded product. With this configuration, the acoustic adjustment member 50 is press-fitted and expands inside the housing 30, so that the acoustic adjustment member 50 is connected to the housing 30 without any gaps.

[0036] The acoustic adjustment member 50 mainly includes a base portion 51 and an acoustic adjustment portion 52 . The base 51 is a substantially cylindrical member having an outer diameter corresponding to the inner peripheral surface of the housing. The base 51 is a member that holds the microphone unit 11 at the lower part of the acoustic adjustment member 50 and is connected to the housing 30.

[0037] The base 51 has a substantially partially cylindrical housing portion 51a on the upper surface. The housing portion 51a has a shape corresponding to the outer periphery of the microphone unit 11. The housing portion 51a is formed across the x direction. The housing portion 51a houses the microphone unit 11 in an assembled state.

[0038] The acoustic adjustment unit 52 is a member disposed on the upper part of the base 51. The base 51 and the acoustic adjustment unit 52 may be integrally formed. The acoustic adjustment unit 52 is a crescent-shaped member. That is, the outer peripheral surface of the acoustic adjustment unit 52 has a shape in which a first curved surface 52a curved in a convex shape and a second curved surface 52b curved in a concave shape are connected. The first curved surface 52a and the second curved surface 52b are cylindrical surfaces, and the curvature of the second curved surface 52b is larger than the curvature of the first curved surface 52a. The first curved surface 52a may be formed along the outer periphery of the base 51. The upper surface of the acoustic adjustment unit 52 abuts against the inner wall of the cover 16.

[0039] With the configuration in which the acoustic adjustment unit 52 and the housing 30 are integrated, even a small microphone 101 can have a long acoustic terminal distance. Therefore, with this configuration, a microphone with high directivity can be realized. Note that the acoustic terminal refers to the position of the air that effectively applies sound pressure to the microphone unit, and is the central position of the air that moves simultaneously with the diaphragm of the microphone unit.

[0040] 6 and 7, the acoustic adjustment unit 52 has a through hole 53 penetrating the first curved surface 52a and the second curved surface 52b in the x direction. The through hole 53 is disposed above the accommodation portion 51a. The microphone unit 11 is accommodated such that the outer peripheral surface of the microphone unit 11 abuts against the accommodation portion 51a and a part of the front surface 11a side is disposed at the position of the through hole 53 from the second curved surface 52b side. As a result, at least a part of the front surface 11a of the microphone unit 11 is opened to the first curved surface 52a side via the through hole 53.

[0041] A front air chamber K111 is formed on the front surface 11a side of the microphone unit 11. The front air chamber K111 is an area surrounded by the front surface 11a of the microphone unit 11, the inner wall of the through hole 53, the cover 16, and the second mesh 15 connected to the outer periphery of the cover 16. A rear air chamber K112 is formed on the rear surface 11b side of the microphone unit 11. The rear air chamber K112 is an area surrounded by the rear surface 11b of the microphone unit 11, the second curved surface 52b of the acoustic adjustment part 52, the cover 16, and the second mesh 15 connected to the outer periphery of the cover 16.

[0042] That is, the acoustic adjustment section 52 divides the inside of the microphone 101 into a front air chamber K111 and a rear air chamber K112.

[0043] The volume of the rear air chamber K112 is sufficiently larger than the volume of the front air chamber K111. Here, if the first mesh 13 with a large acoustic resistance is disposed between the sound source and the microphone unit 11, the distance between the front acoustic terminal and the rear acoustic terminal becomes small, and the vibration of the diaphragm becomes small. Therefore, by making the rear air chamber K112 larger than the front air chamber K111, the impedance on the rear side becomes small, and the driving force of the diaphragm can be secured. That is, according to this configuration, a microphone that is waterproof, water repellent, and highly directional can be realized.

[0044] For example, the volume ratio of the front air chamber K111 to the rear air chamber K112 is 1:7. In this waterproof structure, the volume ratio of the front air chamber K111 to the rear air chamber K112 is preferably about 1:7 to 1:10. The microphone 101 in which the volume ratio of the front air chamber K111 to the rear air chamber K112 is about 1:7 to 1:10 can ensure sufficient driving force of the diaphragm. In this embodiment, if the volume ratio is smaller than 1:7, the sound collection performance in the sound collection band is insufficient. A configuration in which the volume ratio is larger than 1:10 is not preferable due to the constraints of the external shape of the microphone 101.

[0045] 6, in this embodiment, a holding member 121 is disposed between the acoustic adjustment member 50 and the microphone unit 11. The holding member 121 is a partially cylindrical member located on the front surface 11a side of the microphone unit 11. The diameter of the holding member 121 increases from approximately the center toward the upper side. The holding member 121 has a through hole 121a at a position corresponding to the front surface 11a of the microphone unit 11. The holding member 121 may be omitted, and the microphone unit 11 may be held by, for example, the acoustic adjustment part 52 or the fixed part 120.

[0046] In this embodiment, instead of the fixing part 20, a fixing part 120 having a part of the outer circumferential surface linearly cut out is connected to the outer casing 12 and the housing 30. The cutout surfaces of this cutout are approximately parallel to each other. Note that, instead of the fixing part 120, the fixing part 20 having an approximately cylindrical outer periphery may be connected to the outer casing 12 and the housing 30 in this embodiment as well. In this embodiment, the number of cutouts is two, but it may be one, or three or more.

[0047] Acoustic equivalent circuit Here, the configuration of microphone 101 will be explained using an acoustic equivalent circuit. As shown in Fig. 8, an audio signal source P1 and an audio signal source P2 are disposed on the front side and the rear side, respectively, with the microphone unit 11 in between. The audio signal source P1 and the microphone unit 11 located on the front side are separated by an acoustic resistance r f1 , and the acoustic resistance r of the second mesh 15 f2 Also, the acoustic resistance r f1 and acoustic resistance r f2 Between them, there is an acoustic stiffness S caused by the first air gap K1. f1 are connected in parallel. Furthermore, the acoustic resistance r f2 Between the microphone unit 11 and the microphone unit 11, there is an acoustic stiffness S generated by the front air chamber K111. f2 are connected in parallel.

[0048] The audio signal source P2 and the microphone unit 11 located on the rear side are connected in series with each other through the acoustic resistance r r1 , and the acoustic resistance r of the second mesh 15 r2 In addition, between the audio signal source P2 and the microphone unit 11, an acoustic resistance r r1 and acoustic resistance r r2 Between them, there is an acoustic stiffness S caused by the first air gap K1. r1 are connected in parallel. Here, the acoustic resistance r r1 and acoustic resistance r f1 , acoustic resistance r r2 and acoustic resistance rf2 , acoustic stiffness S r1 and acoustic stiffness S f1 are approximately equal to each other.

[0049] acoustic resistance r r2 Between the microphone unit 11 and the microphone unit 11, an acoustic stiffness S generated by the rear air chamber K112 is provided. r2 are connected in parallel, where the acoustic stiffness S f2 and acoustic stiffness S r2 If the difference between these is small, in a specified frequency range where the distance between the front sound wave introduction hole and the rear sound wave introduction hole and the half-length of the sound wave are the same, resonance occurs on the front side and the rear side of the microphone unit 11, and a load is generated on the diaphragm inside the microphone unit 11. In other words, the level of the sound waves picked up in that frequency range becomes small.

[0050] Acoustic Stiffness S f2 and acoustic stiffness S r2 When the difference between the front and rear sides is sufficiently large, a phase difference and a pressure difference occur between the front and rear sides, and the diaphragm operates sufficiently. Therefore, the microphone of the second embodiment operates as a pressure gradient microphone and has high directivity because the diaphragm has sufficient driving force. In addition, by shifting the resonance frequency between the front side and the rear side, the resonance at the above-mentioned predetermined frequency is suppressed.

[0051] Frequency response characteristics Figures 9 and 10 show the frequency response characteristics of a microphone. That is, the horizontal axis shows frequency and the vertical axis shows output level (dBV). Characteristic A shows the characteristics when sound waves arrive at 0 degrees to the sound collection axis, i.e. from the front, characteristic B shows the characteristics when sound waves arrive at 90 degrees, i.e. from the side, and characteristic C shows the characteristics when sound waves arrive at 180 degrees, i.e. from behind. The test conditions in Figures 9 and 10 are the same except for the volume ratio between the front air chamber and the rear air chamber.

[0052] FIG. 10(a) shows the frequency response characteristics of a microphone with a volume ratio of the front air chamber to the rear air chamber of 1:2.5, FIG. 10(b) shows the frequency response characteristics of a microphone with a volume ratio of 1:3, and FIG. 10(c) shows the frequency response characteristics of a microphone with a volume ratio of 1:3.5. In each figure, a downward peak appears in each characteristic in frequency range F, which is near the high-frequency limit frequency. In other words, a microphone with this configuration cannot adequately collect sound in frequency range F of the sound collection band. This is because, in that frequency range F, the acoustic equivalent circuits configured on the front and rear sides resonate with each other, reducing the vibration of the diaphragm. In addition, according to each figure, the downward peak becomes smaller as the volume ratio increases.

[0053] Fig. 9 shows the frequency response characteristics of a microphone with a volume ratio of the front air chamber K111 to the rear air chamber K112 of 1:7. In the figure, the frequency response characteristics also drop smoothly in the frequency domain F. In other words, a microphone with this configuration can adequately collect sound across the entire sound collection band.

[0054] In this way, a microphone in which the volume of the rear air chamber is sufficiently larger than the volume of the front air chamber can collect sound well across the entire sound collection frequency band.

[0055] According to the embodiment described above, a microphone with high waterproof and water-repellent properties can be realized. [Explanation of symbols]

[0056] 1 microphone 11 Microphone unit 12 Exterior components 13 1st mesh 14 Cover 15 2nd mesh 101 Microphone 50 Acoustic adjustment components

Claims

1. An outer shell member having a sound hole; A first mesh made of tatami weave is disposed inside the outer shell member; a spacer having a diameter corresponding to an inner diameter of the outer member, a first surface of the spacer being in contact with the first mesh and pressing the first mesh against the inside of the outer member; a second mesh having water repellency and in contact with a second surface of the spacer; A microphone unit accommodated below the second mesh; Equipped with the spacer includes a rib protruding toward the second mesh around an entire periphery of the spacer; Further comprising a second gap defined by the second mesh, the rib, and the inner wall of the outer shell member. Microphone.

2. the spacer includes a through hole penetrating the first surface and the second surface, a first gap defined by a side wall of the through hole, the first mesh, and the second mesh; 2. The microphone of claim 1.

3. an acoustic adjustment member for supporting the microphone unit below the second mesh; The acoustic adjustment member is an acoustic adjustment section that divides a front air chamber formed on a front side of the microphone unit and a rear air chamber formed on a rear side of the microphone unit; a through hole formed in the acoustic adjustment unit and opening at least a part of the front surface to the front air chamber; having The volume of the rear air chamber is larger than the volume of the front air chamber.

3. The microphone according to claim 1 or 2.

4. The volume ratio of the front air chamber to the rear air chamber is between 1:7 and 1:

10.

4. The microphone according to claim 3.

5. The acoustic adjustment unit has a first convex curved surface and a second concave curved surface, and a front surface of the microphone unit abuts against the second curved surface.

5. The microphone according to claim 3 or 4.

6. An outer shell member having a sound hole; A first mesh made of tatami weave is disposed inside the outer shell member; a spacer having a diameter corresponding to an inner diameter of the outer member, a first surface of the spacer being in contact with the first mesh and pressing the first mesh against the inside of the outer member; a second mesh having water repellency and in contact with a second surface of the spacer; A microphone unit accommodated below the second mesh; an acoustic adjustment member that supports the microphone unit below the second mesh; Equipped with The acoustic adjustment member is an acoustic adjustment section that divides a front air chamber formed on a front side of the microphone unit and a rear air chamber formed on a rear side of the microphone unit; a through hole formed in the acoustic adjustment unit and opening at least a part of the front surface to the front air chamber; having The volume of the rear air chamber is larger than the volume of the front air chamber, The acoustic adjustment unit has a first convex curved surface and a second concave curved surface, and a front surface of the microphone unit abuts against the second curved surface. Microphone.

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