Bone conduction microphone

Abstract

The bone conduction microphone of the utility model comprises a circuit board having an acoustic channel; the shell is in covering connection with the circuit board to form an accommodating space; the metal cover is arranged in the containing space and connected with the circuit board in a covering mode to form a first cavity, and the metal cover comprises a top wall arranged with the circuit board in a spaced mode and a side wall located between the top wall and the circuit board; the vibration assembly is arranged in the containing space and connected with the top wall in a covering mode to form a second cavity, the vibration assembly comprises a vibration piece arranged with the top wall in a spaced mode and a spacer located between the vibration piece and the top wall, and a first conduction cavity is defined by the shell, the vibration assembly, the metal cover and the circuit board; the MEMS chip is arranged in the first cavity and fixed to the circuit board, the MEMS chip is provided with a back cavity, the acoustic channel is communicated with the first conduction cavity and the back cavity, and vibration of the vibration piece is conducted to one side of the MEMS chip through the first conduction cavity, the acoustic channel and the back cavity. The bone conduction microphone provided by the utility model can reduce the influence of electromagnetic interference and improve the signal-to-noise ratio.

Description

[Technical field]

[0001] The utility model relates to the field of sound-to-electricity conversion, in particular to a bone conduction microphone. [Background technology]

[0002] Bone conduction microphones use the slight vibrations of the head and neck bones caused by speaking to convert them into electrical signals. Unlike traditional microphones that collect sound through air conduction, bone conduction microphones can restore sound with high clarity even in noisy environments, thus avoiding noise interference caused by airborne sound and ensuring high sound quality. However, due to the influence of electromagnetic interference on the MEMS chip and ASIC chip in the bone conduction microphones of related technologies, the signal-to-noise ratio is insufficient.

[0003] Therefore, it is necessary to provide a new bone conduction microphone to solve the above technical problems. [Utility Model Content]

[0004] The purpose of the utility model is to overcome the above technical problems and provide a bone conduction microphone which can reduce the influence of electromagnetic interference and improve the signal-to-noise ratio.

[0005] In order to achieve the above object, the utility model provides a bone conduction microphone, comprising:

[0006] A circuit board having an acoustic channel;

[0007] A housing, connected with the circuit board cover to form a receiving space;

[0008] A metal cover is arranged in the receiving space and connected with the circuit board to form a first cavity, the metal cover comprising a top wall spaced apart from the circuit board and a side wall located between the top wall and the circuit board;

[0009] a vibration assembly, arranged in the receiving space and connected to the top wall to form a second cavity, the vibration assembly comprising a vibration member spaced apart from the top wall and a spacer between the vibration member and the top wall, the housing, the vibration assembly, the metal cover and the circuit board enclose a first conduction cavity;

[0010] A MEMS chip is disposed in the first cavity and fixed to the circuit board. The MEMS chip has a back cavity. The acoustic channel connects the first conduction cavity and the back cavity. The vibration of the vibrator is conducted to one side of the MEMS chip via the first conduction cavity, the acoustic channel and the back cavity.

[0011] Preferably, the top wall is provided with a connecting hole connecting the first cavity and the second cavity, the first cavity, the connecting hole and the second cavity form a second conduction cavity, and the vibration of the vibrator is also conducted to the other side of the MEMS chip through the second conduction cavity.

[0012] Preferably, the top wall is a metal plate having a porous structure, the porous structure is arranged in an array, and the connecting holes are the porous structure.

[0013] Preferably, the top wall is a metal mesh, and the connecting holes are mesh holes of the metal mesh.

[0014] Preferably, the metal cover is an integrally formed structure, or the metal cover is formed by fixedly connecting the top wall and the side walls.

[0015] Preferably, the vibration member includes a vibration membrane fixed to the spacer and a mass block fixed on the vibration membrane.

[0016] Preferably, the bone conduction microphone further includes an ASIC chip electrically connected to the MEMS chip, and the ASIC chip is disposed in the first cavity and fixed to the circuit board.

[0017] Preferably, the shell is a metal shell.

[0018] Preferably, the spacer is a part of the top wall, and a protrusion of the top wall extending in a direction away from the circuit board forms the spacer.

[0019] Preferably, the spacer is a part of the vibration membrane, and a protrusion of the vibration membrane extending in a direction close to the circuit board forms the spacer.

[0020] Preferably, the vibration membrane is a breathable membrane.

[0021] Preferably, the MEMS chip comprises a diaphragm, and the diaphragm is a gas permeable membrane.

[0022] In the bone conduction microphone of the utility model, the metal cover can play the role of electromagnetic shielding, thereby reducing the impact of electromagnetic interference on the MEMS chip and the ASIC chip, and improving the signal-to-noise ratio of the bone conduction microphone. In addition, the top wall of the metal cover can also protect the MEMS chip and the ASIC chip from the impact of the vibrating part, thereby improving the reliability of the bone conduction microphone.

Brief Description of the Drawings

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in the field of the present invention, other drawings can be obtained based on these drawings without creative work, among which:

[0024] Figure 1 It is a schematic diagram of the structure of the bone conduction microphone of the utility model;

[0025] Figure 2 It is a structural schematic diagram of the top wall of the metal cover of the bone conduction microphone of the present invention;

[0026] Figure 3 It is a schematic structural diagram of another bone conduction microphone of the present invention. [Specific implementation method]

[0027] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in the field of the utility model without creative work are within the scope of protection of the utility model.

[0028] See also Figure 1 As shown, the utility model provides a bone conduction microphone 100, which includes a circuit board 1 with an acoustic channel 10, a shell 2 covered with the circuit board 1 to form a receiving space, a metal cover 3 arranged in the receiving space and covered with the circuit board 1 to form a first cavity 30, a vibration component 4 arranged in the receiving space, and a MEMS chip 5 with a back cavity 50 arranged in the first cavity 30 and fixed to the circuit board 1.

[0029] The metal cover 3 includes a top wall 31 spaced apart from the circuit board 1 and a side wall 32 located between the top wall 31 and the circuit board 1 .

[0030] The vibration assembly 4 includes a vibration member 41 spaced apart from the top wall 31 and a spacer 42 located between the vibration member 41 and the top wall 31. The vibration assembly 4 and the top wall 31 are covered to form a second cavity 40.

[0031] The housing 2, the vibration assembly 4, the metal cover 3 and the circuit board 1 enclose a first conduction cavity 101. The acoustic channel 10 connects the first conduction cavity 101 and the back cavity 50. The vibration of the vibration member 41 is conducted to one side of the MEMS chip 5 via the first conduction cavity 101, the acoustic channel 10 and the back cavity 50.

[0032] The vibrating member 41 includes a vibrating membrane 411 fixed to the spacer 42 and a mass block 412 fixed to the vibrating membrane 411. The mass block 412 is fixed below the vibrating membrane 411. Figure 3 In the illustrated embodiment, the mass block 412 may also be fixed above the vibration membrane 411. Optionally, the vibration membrane 411 may be a breathable membrane, and the breathable membrane may be formed by making the membrane body of the vibration membrane 411 from a breathable material, or by providing the vibration membrane 411 with a breathable structure, and the breathable structure is not limited to holes, gaps, cutouts, movable valves, etc.

[0033] The bone conduction microphone 100 further includes an ASIC chip 6 electrically connected to the MEMS chip 5, and the ASIC chip 6 is disposed in the first cavity 30 and fixed to the circuit board 1. In other embodiments, the ASIC chip 6 may also be fixed to the metal cover 3, or integrated with the MEMS chip 5.

[0034] The metal cover 3 can play the role of electromagnetic shielding, thereby reducing the impact of electromagnetic interference on the MEMS chip 5 and the ASIC chip 6, and improving the signal-to-noise ratio of the bone conduction microphone 100. In addition, the top wall 31 can also protect the MEMS chip 5 and the ASIC chip 6 from the impact of the vibration member 41, thereby improving the reliability of the bone conduction microphone 100.

[0035] As an option, the housing 2 may be a metal shell, thereby further improving the electromagnetic shielding effect and increasing the overall structural strength of the bone conduction microphone 100 .

[0036] As an option, the metal cover 3 may be an integrally formed structure, or the metal cover 3 may be formed by fixing the top wall 31 and the side wall 32 together, and the fixing connection may be welding or gluing.

[0037] As an optional method, the top wall 31 can be a wall structure without holes, or the top wall 31 can also be provided with a connecting hole 311 connecting the first cavity 30 and the second cavity 40. In this method, the first cavity 30, the connecting hole 311 and the second cavity 40 form a second conduction cavity 102, and the vibration of the vibrator 41 is also conducted to the other side of the MEMS chip 5 through the second conduction cavity 102, thereby improving the sensitivity of the bone conduction microphone 100 in a differential manner. Figure 2 In the illustrated embodiment, the top wall 31 may be a metal plate having a porous structure 3111, the porous structure 3111 is arranged in an array, and the connecting hole 311 is the porous structure 3111. In other embodiments, the top wall 31 may also be a metal mesh, and the connecting hole 311 is the mesh of the metal mesh. It should be noted that the number of the connecting holes 311 may be a single hole, a double hole, or multiple holes with more than two holes. The utility model does not limit the number, position, shape, size, formation method, and arrangement method of the connecting holes 311, as long as the first cavity 30 and the second cavity 40 can be connected.

[0038] As an optional method, the MEMS chip 5 includes a diaphragm 51, and the diaphragm 51 can be a breathable membrane. The breathable membrane can be formed by making the membrane body of the diaphragm 51 from a breathable material, or the diaphragm 51 is provided with a breathable structure, and the breathable structure is not limited to holes, gaps, incisions, movable valves, etc.

[0039] As an option, the spacer 42 can be an independent frame structure, or the spacer 42 can also be a part of the top wall 31, and the protrusion of the top wall 31 extending in the direction away from the circuit board 1 forms the spacer 42, or the spacer 42 is a part of the vibration membrane 411, and the protrusion of the vibration membrane 411 extending in the direction close to the circuit board 1 forms the spacer 42.

[0040] The above is only an implementation method of the present invention. It should be pointed out that ordinary technicians in the field of the present invention can make improvements 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 bone conduction microphone, characterized in that: include: A circuit board having an acoustic channel; A housing, connected with the circuit board cover to form a receiving space; A metal cover is arranged in the receiving space and connected with the circuit board to form a first cavity, the metal cover comprising a top wall spaced apart from the circuit board and a side wall located between the top wall and the circuit board; a vibration assembly, arranged in the receiving space and connected to the top wall to form a second cavity, the vibration assembly comprising a vibration member spaced apart from the top wall and a spacer between the vibration member and the top wall, the housing, the vibration assembly, the metal cover and the circuit board enclose a first conduction cavity; A MEMS chip is disposed in the first cavity and fixed to the circuit board. The MEMS chip has a back cavity. The acoustic channel connects the first conduction cavity and the back cavity. The vibration of the vibrator is conducted to one side of the MEMS chip via the first conduction cavity, the acoustic channel and the back cavity.

2. The bone conduction microphone according to claim 1, characterized in that: The top wall is provided with a connecting hole connecting the first cavity and the second cavity. The first cavity, the connecting hole and the second cavity form a second conduction cavity. The vibration of the vibrator is also conducted to the other side of the MEMS chip through the second conduction cavity.

3. The bone conduction microphone according to claim 2, characterized in that: The top wall is a metal plate with a porous structure, the porous structure is arranged in an array, and the connecting holes are the porous structure.

4. The bone conduction microphone according to claim 2, characterized in that: The top wall is a metal mesh, and the connecting holes are mesh holes of the metal mesh.

5. The bone conduction microphone according to claim 1, characterized in that: The metal cover is an integrally formed structure, or the metal cover is formed by fixedly connecting the top wall and the side wall.

6. The bone conduction microphone according to claim 1, characterized in that: The vibration member includes a vibration membrane fixed to the spacer and a mass block fixed on the vibration membrane.

7. The bone conduction microphone according to claim 1, characterized in that: The bone conduction microphone further includes an ASIC chip electrically connected to the MEMS chip. The ASIC chip is disposed in the first cavity and fixed to the circuit board.

8. The bone conduction microphone according to claim 1, characterized in that: The shell is a metal shell.

9. The bone conduction microphone according to claim 1, characterized in that: The spacer is a part of the top wall, and a protrusion of the top wall extending in a direction away from the circuit board forms the spacer.

10. The bone conduction microphone according to claim 6, characterized in that: The spacer is a part of the vibration membrane, and a protrusion of the vibration membrane extending in a direction close to the circuit board forms the spacer.

11. The bone conduction microphone according to claim 6, characterized in that: The vibration membrane is a breathable membrane.

12. The bone conduction microphone according to claim 1, characterized in that: The MEMS chip includes a diaphragm, and the diaphragm is a gas-permeable membrane.

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