Directional microphone module

Abstract

Disclosed is a directional microphone module, comprising: a sound-transmitting mesh fabric, a housing covered with the sound-transmitting mesh fabric, a circuit board fixed to the housing, and a MEMS microphone fixed to the circuit board. The housing comprises a top wall and side walls; the circuit board and the top wall are spaced apart to form a first cavity; the circuit board and the sound-transmitting mesh fabric are spaced apart to form a second cavity; the side walls comprise two first side walls arranged opposite to each other and two second side walls arranged opposite to each other; the first cavity and the second cavity are communicated only at one of the two second side walls; the MEMS microphone is arranged in the first cavity and located at the other of the two second side walls; the MEMS microphone is provided with a first sound hole facing the top wall and a second sound hole facing the circuit board; the first sound hole is communicated with the first cavity; the circuit board is provided with a through hole; and the second sound hole is communicated with the second cavity by means of the through hole. The directional microphone module of the present disclosure has stable performance and simple structure, and can improve production efficiency and reduce labor costs.

Description

Directional microphone module Technical Field

[0001] The utility model relates to the field of sound-to-electricity conversion, in particular to a directional microphone module. Background Art

[0002] Directional microphone modules in related technologies usually use a built-in pressure-difference electret microphone to achieve directivity. Technical issues

[0003] However, the performance of pressure-gap electret microphones degrades over time, making them unstable and unsuitable for long-term applications. Furthermore, assembly of pressure-gap electret microphones requires surface mounting and manual soldering, resulting in low production efficiency and high labor costs.

[0004] Therefore, it is necessary to provide a new directional microphone module to solve the above technical problems. Technical Solutions

[0005] The purpose of the present invention is to overcome the above technical problems and provide a directional microphone module with stable performance, simple structure, improved production efficiency and reduced labor costs.

[0006] In order to achieve the above-mentioned purpose, the present invention provides a directional microphone module, comprising a sound-transmitting mesh, a shell connected to the sound-transmitting mesh to form a receiving space, a circuit board arranged in the receiving space and fixed to the shell, and a MEMS microphone arranged in the receiving space and fixed to the circuit board, the shell comprising a top wall spaced apart from the sound-transmitting mesh and a side wall extending from the top wall and fixedly connected to the sound-transmitting mesh, the circuit board being arranged between the top wall and the sound-transmitting mesh, and the circuit board and the top wall being spaced apart to form a first cavity, and the circuit board and the sound-transmitting mesh being spaced apart to form a second cavity The side wall includes two first side walls arranged opposite to each other and two second side walls arranged opposite to each other connecting the two first side walls. The first cavity and the second cavity are connected only at one of the two second side walls. The MEMS microphone is arranged in the first cavity and located at the other of the two second side walls. The MEMS microphone is provided with a first sound hole facing the top wall and a second sound hole facing the circuit board. The first sound hole is connected to the first cavity. The circuit board is provided with a through hole connecting the second sound hole and the second cavity. The second sound hole is connected to the second cavity through the through hole.

[0007] Preferably, the directional microphone module has a long axis and a short axis arranged perpendicular to the long axis, the two first side walls extend along the long axis, the two second side walls extend along the short axis, and in the direction along the long axis, the circuit board is spaced apart from the one second side wall.

[0008] Preferably, the top wall, the circuit board and the sound-transmitting mesh are arranged in parallel, and the distance between the circuit board and the top wall is equal to the distance between the circuit board and the sound-transmitting mesh.

[0009] Preferably, the second sound hole is closer to the other second side wall than the first sound hole.

[0010] Preferably, the housing is provided with a step portion extending from the top wall toward the direction close to the sound-permeable mesh, the step portion only extends along the two first side walls and the other second side wall, and the circuit board is fixed to the step portion.

[0011] Preferably, the first sound hole, the second sound hole and the through hole are all circular holes, and the circular hole center of the second sound hole and the circular hole center of the through hole are on a straight line.

[0012] Preferably, the circular aperture of the through hole is larger than the circular aperture of the second sound hole.

[0013] Preferably, the first sound hole, the second sound hole and the through hole are all located in the middle between the two first side walls.

[0014] Preferably, the MEMS microphone is fixed to the circuit board by surface mounting technology. Beneficial effects

[0015] The directional microphone module of the present invention adopts a double-sided sound-inlet MEMS microphone in conjunction with a shell, a sound-transparent mesh and a circuit board to achieve directionality. The overall structure is simple. At the same time, since the performance of the MEMS microphone is stable during operation, the directional microphone module of the present invention can be applied to scenarios that require long-term operation. In addition, the MEMS microphone is easy to assemble and can be surface-mounted in one step without the need for manual welding, thereby improving production efficiency and reducing labor costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art in the field of the present invention, other drawings can be obtained based on these drawings without creative work. Among them:

[0017] FIG1 is a schematic diagram of the exploded structure of a directional microphone module of the present invention;

[0018] FIG2 is a schematic structural diagram of a housing of a directional microphone module of the present invention;

[0019] FIG3 is a schematic cross-sectional view of the directional microphone module of the present invention;

[0020] FIG4 is a schematic diagram of a sound propagation path of a sound in a first direction received by a directional microphone module of the present invention;

[0021] FIG5 is a schematic diagram of a sound propagation path for receiving sound in a second direction by the directional microphone module of the present invention. Best Mode for Carrying Out the Invention

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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 the field of the present invention without making creative efforts are within the scope of protection of the present invention.

[0023] Please refer to Figures 1-3. The present invention provides a directional microphone module 100, which includes a sound-transmitting mesh 1, a shell 2 covering the sound-transmitting mesh 1 to form a receiving space, a circuit board 3 arranged in the receiving space and fixed to the shell 2, and a MEMS microphone 4 arranged in the receiving space and fixed to the circuit board 3.

[0024] The MEMS microphone 4 is fixed to the circuit board 3 by surface mounting technology.

[0025] The housing 2 includes a top wall 21 spaced apart from the sound-transmitting mesh 1 and a side wall 22 extending from the top wall 21 and fixedly connected to the sound-transmitting mesh 1 .

[0026] The circuit board 3 is disposed between the top wall 21 and the sound-transmitting mesh 1 , and the circuit board 3 and the top wall 21 are spaced apart to form a first cavity 11 , and the circuit board 3 and the sound-transmitting mesh 1 are spaced apart to form a second cavity 12 .

[0027] The sidewalls 22 include two first sidewalls 221 disposed opposite each other and two second sidewalls 222 disposed opposite each other and connecting the two first sidewalls 221. The directional microphone module 100 has a long axis X and a short axis Y disposed perpendicular to the long axis X. The two first sidewalls 221 extend along the long axis X, and the two second sidewalls 222 extend along the short axis Y.

[0028] The first cavity 11 and the second cavity 12 are connected only at one of the two second side walls 222, 222a. The MEMS microphone 4 is disposed within the first cavity 11 and located at the other of the two second side walls 222, 222b. Along the longitudinal axis X, the circuit board 3 is spaced apart from the one second side wall 222a.

[0029] The MEMS microphone 4 is provided with a first sound hole 41 facing the top wall 21 and a second sound hole 42 facing the circuit board 3. The first sound hole 41 is connected to the first cavity 11. The circuit board 3 is provided with a through hole 31 connecting the second sound hole 42 and the second cavity 12. The second sound hole 42 is connected to the second cavity 12 through the through hole 31.

[0030] The housing 2 is provided with a step portion 23 extending from the top wall 21 toward the sound-permeable mesh 1 . The step portion 23 extends only along the two first side walls 221 and the other second side wall 222 b . The circuit board 3 is fixed to the step portion 23 .

[0031] The top wall 21 , the circuit board 3 and the sound-transmitting mesh 1 are arranged in parallel, and the distance d1 between the circuit board 3 and the top wall 21 is equal to the distance d2 between the circuit board 3 and the sound-transmitting mesh 1 .

[0032] The second sound hole 42 is closer to the other second side wall 222 b than the first sound hole 41 .

[0033] The first sound hole 41 , the second sound hole 42 and the through hole 31 are all circular holes, and the center of the circular hole of the second sound hole 42 and the center of the circular hole of the through hole 31 are on a straight line Z.

[0034] The circular aperture of the through hole 31 is larger than the circular aperture of the second sound hole 42 .

[0035] The first sound hole 41 , the second sound hole 42 and the through hole 31 are all located in the middle between the two first side walls 221 .

[0036] Please refer to Figures 4-5. Figure 4 is a schematic diagram of the sound propagation path of the directional microphone module 100 receiving sound in a first direction. The sound in the first direction enters the MEMS microphone through the first sound hole and the second sound hole respectively along the two sound propagation paths shown by the dotted lines in Figure 4. The sound propagation path of the sound entering the MEMS microphone through the first sound hole is longer, and the sound propagation path of the sound entering the MEMS microphone through the second sound hole is shorter, so that the sound signals on the positive and negative sides form a pressure difference signal. Figure 5 is a schematic diagram of the sound propagation path of the directional microphone module 100 receiving sound in the second direction. The sound in the second direction enters the MEMS microphone through the first sound hole and the second sound hole respectively along the two sound propagation paths shown by the dotted lines in Figure 5. The sound propagation path of the sound entering the MEMS microphone through the first sound hole and the sound propagation path of the sound entering the MEMS microphone through the second sound hole are almost the same length, so that the sound signals on the positive and negative sides cancel each other out. Therefore, due to the difference in sound propagation paths of sounds from different directions, the directional microphone module 100 achieves directionality.

[0037] The directional microphone module of the present invention adopts a double-sided sound-inlet MEMS microphone in conjunction with a shell, a sound-transparent mesh and a circuit board to achieve directionality. The overall structure is simple. At the same time, since the performance of the MEMS microphone is stable during operation, the directional microphone module of the present invention can be applied to scenarios that require long-term operation. In addition, the MEMS microphone is easy to assemble and can be surface-mounted in one step without the need for manual welding, thereby improving production efficiency and reducing labor costs.

[0038] The above is only an implementation method of the present invention. It should be pointed out that for ordinary technicians in the field of the present invention, improvements can be made without departing from the creative concept of the present invention, but these all fall within the scope of protection of the present invention.

Claims

1. A directional microphone module, characterized in that: The invention comprises an acoustically transparent mesh, a housing connected to the acoustically transparent mesh to form a receiving space, a circuit board disposed in the receiving space and fixed to the housing, and a MEMS microphone disposed in the receiving space and fixed to the circuit board. The housing comprises a top wall spaced apart from the acoustically transparent mesh and a side wall extending from the top wall and fixedly connected to the acoustically transparent mesh. The circuit board is disposed between the top wall and the acoustically transparent mesh, and the circuit board and the top wall are spaced apart to form a first cavity. The circuit board and the acoustically transparent mesh are spaced apart to form a second cavity. The side wall comprises two first side walls disposed opposite each other and two second side walls disposed opposite each other connecting the two first side walls. The first cavity and the second cavity are connected only at one of the two second side walls. The MEMS microphone is disposed in the first cavity and located at the other of the two second side walls. The MEMS microphone is provided with a first sound hole facing the top wall and a second sound hole facing the circuit board. The first sound hole is connected to the first cavity. The circuit board is provided with a through hole connecting the second sound hole and the second cavity. The second sound hole is connected to the second cavity via the through hole.

2. The directional microphone module according to claim 1, wherein: The directional microphone module has a long axis and a short axis perpendicular to the long axis, the two first side walls extend along the long axis, the two second side walls extend along the short axis, and in the direction along the long axis, the circuit board is spaced apart from the one second side wall.

3. The directional microphone module according to claim 1, wherein: The top wall, the circuit board and the sound-transmitting mesh are arranged in parallel, and the distance between the circuit board and the top wall is equal to the distance between the circuit board and the sound-transmitting mesh.

4. The directional microphone module according to claim 1, wherein: The second sound hole is closer to the other second side wall than the first sound hole.

5. The directional microphone module according to claim 1, wherein: The housing is provided with a step portion extending from the top wall toward the direction close to the sound-permeable mesh, the step portion only extends along the two first side walls and the other second side wall, and the circuit board is fixed to the step portion.

6. The directional microphone module according to claim 1, characterized in that: The first sound hole, the second sound hole and the through hole are all circular holes, and the circular hole center of the second sound hole and the circular hole center of the through hole are on a straight line.

7. The directional microphone module according to claim 6, characterized in that: The circular aperture of the through hole is larger than the circular aperture of the second sound hole.

8. The directional microphone module according to claim 1, wherein: The first sound hole, the second sound hole and the through hole are all located in a middle position between the two first side walls.

9. The directional microphone module according to claim 1, wherein: The MEMS microphone is fixed to the circuit board through surface mounting technology.

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