Bone conduction microphone

Abstract

The utility model provides a bone conduction microphone, which belongs to the technical field of microphones and comprises a first shell, a circuit board is arranged at an opening outside the first shell, a second shell is arranged on the periphery of the first shell, and a first cavity is formed among the second shell, the circuit board and the first shell. A vibration assembly is arranged at the position, located in the first cavity, of the outer side of the first shell, a second cavity is formed between the vibration assembly and the first shell, and the size of the second cavity is not larger than one third of the size of the first cavity; according to the utility model, the vibration assembly is changed, so that the first cavity can generate large airflow or air pressure change more easily, and the sensitivity is improved; the selection range of the vibration piece to the elastic material is wider, the selection range of the mass block to the size and the weight is wider, and performance optimization is easier to achieve. Due to the arrangement of the double-layer metal shell of the first shell and the second shell, the anti-interference performance is better.

Description

Technical Field

[0001] This utility model relates to a microphone.

[0002] Specifically, it involves a bone conduction microphone. Background Technology

[0003] Bone conduction microphones, as a new type of microphone that only picks up vibration signals, are widely used in TWS earphones to reduce noise and wind noise. The most mature solution at present is to use a diaphragm and a mass block to sense the signal from the human skull and convert the vibration signal into an electrical signal for output.

[0004] Common solutions are as follows: (see attached) Figure 1 After the vibration is transmitted to bone conduction, due to inertia, the internal mass block drives the diaphragm to vibrate. The resulting acoustic pressure difference between cavity 100 and cavity 200 acts on the MEMS, causing the MEMS diaphragm to vibrate and convert it into an electrical signal, which is then output by the ASIC. This forms a small voltage signal, which is processed by the ASIC and output, ultimately completing the conversion from vibration signal to electrical signal. The main disadvantage of this method is that the cavity 200 has a large space, resulting in a small pressure difference acting on the MEMS diaphragm, leading to lower sensitivity. Additionally, the process of encapsulating the mass block inside the metal shell 300 is difficult, making it hard to guarantee consistency and stability. Utility Model Content

[0005] The purpose of this invention is to overcome the shortcomings of the above-mentioned traditional technologies and provide a bone conduction microphone.

[0006] The purpose of this utility model is achieved through the following technical measures: a bone conduction microphone, including a first housing, a circuit board provided at the opening outside the first housing, and a second housing provided on the outer periphery of the first housing, the second housing, the circuit board and the first housing forming a first cavity, characterized in that: a vibration component is provided on the outer side of the first housing within the first cavity, the vibration component and the first housing forming a second cavity, the volume of the second cavity not exceeding one-third of the volume of the first cavity.

[0007] As an improvement, the vibration assembly includes a support member disposed on the first housing, a vibrating element disposed at one end of the support member away from the first housing, a mass block disposed on the vibrating element, and the support member, the vibrating element and the first housing forming the second cavity.

[0008] As a further improvement, the mass block is disposed on the side of the vibrating element close to the first housing, the distance H1 from the upper surface of the mass block to the first housing, and the thickness h1 of the mass block, H1≤1 / 2h1.

[0009] As a further improvement, the end of the support member away from the first housing extends and connects to the second housing, and a third cavity is formed between the support member, the second housing, and the vibrating member, wherein the volume of the second cavity is not greater than half the volume of the third cavity.

[0010] As a further improvement, the mass block is positioned on the vibrating element away from the first cavity. side The distance H2 from the lower surface of the mass block to the second shell is given, and the thickness of the mass block is h1, H2 ≤ 1 / 2h1.

[0011] As a further improvement, the vibrating element is a diaphragm or an FPC flexible board.

[0012] As a further improvement, the first housing is a metal housing.

[0013] As a further improvement, the second housing is a metal housing.

[0014] As a further improvement, the first housing is provided with a microphone assembly, which includes MEMS and ASIC.

[0015] As a further improvement, the first housing includes an electrical connection board through which the microphone assembly is electrically connected to the circuit board.

[0016] Due to the adoption of the above technical solution, the advantages of this utility model compared with the prior art are:

[0017] This invention improves sensitivity by modifying the vibration component, making it easier for the first cavity to generate larger airflow or air pressure changes; the vibrating element has a wider range of choices for elastic materials, and the mass block has a wider range of choices for size and weight, making it easier to optimize performance; the double-layer metal shell design of the first and second shells provides better anti-interference performance.

[0018] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0019] Appendix Figure 1 This is a schematic diagram of the existing technology structure;

[0020] Appendix Figure 2 This is a schematic diagram of the structure of Embodiment 1;

[0021] Appendix Figure 3 This is a schematic diagram of the structure of Embodiment 2;

[0022] Appendix Figure 4 This is a schematic diagram of the structure of Embodiment 3;

[0023] Appendix Figure 5 This is another schematic diagram of the MEMS and ASIC structure described in Embodiment 3;

[0024] Appendix Figure 6 This is another schematic diagram of the MEMS and ASIC structure described in Embodiment 3;

[0025] Appendix Figure 7 This is another schematic diagram of the MEMS and ASIC structures described in Embodiment 3. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0027] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0028] In this utility model, unless otherwise explicitly specified and limited, the terms "installation", "setting", "connection", "fixing", "screw connection", etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0029] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0030] Example 1: As shown in the attached document Figure 2 As shown, a bone conduction microphone includes a first housing 1, a circuit board 2 at an opening outside the first housing 1, and a second housing 3 on the outer periphery of the first housing 1. Both the first housing 1 and the second housing 3 are metal housings, forming a double-layer metal housing for better anti-interference performance. The second housing 3 has a first equalization hole 31 with a diameter <0.1mm. The first housing 1 has a through hole 11 leading to a diaphragm of a MEMS, and the diameter of the through hole 11 must be smaller than the diameter of the MEMS back cavity.

[0031] A first cavity 4 is formed between the second housing 3, the circuit board 2 and the first housing 1. A vibration component 5 is provided on the outside of the first housing 1 inside the first cavity 4. A second cavity 6 is formed between the vibration component 5 and the first housing 1. The volume of the second cavity 6 is no more than one-third of the volume of the first cavity 4, which makes it easier to generate a larger air pressure difference, thereby improving sensitivity.

[0032] The vibration assembly 5 includes a support member 51 disposed on the first housing 1, and a vibration member 52 is provided at one end of the support member 51 away from the first housing 1. The vibration member 52 is a diaphragm or an FPC flexible board.

[0033] The vibration component 5 is provided with a second equalizing hole 54, the diameter of which is <0.1mm.

[0034] The length and width of the vibration component 5 are at least 0.2 mm smaller than the length and width of the first housing 1.

[0035] The mass block 53 is disposed on the side of the vibrating member 52 near the first housing 1. The distance H1 from the upper surface of the mass block 53 to the first housing 1 is 1. The thickness of the mass block 53 is h1, and H1 ≤ 1 / 2h1.

[0036] The first housing 1 contains a MEMS 8 and an ASIC 9 that are electrically connected through a connecting plate 7 and gold wires.

[0037] The vibration assembly 5, formed by the vibrating element 52 and the mass block 53, is directly attached to the outer plane of the first housing 1, making the process easier to implement and allowing for monitoring of firmness and ensuring consistency.

[0038] Example 2: As shown in the attached document Figure 3 As shown, the structure is the same as in Embodiment 1, except that: the end of the support member 51 away from the first housing 1 extends and connects to the second housing 3, and a third cavity 10 is formed between the support member 51, the second housing 3 and the vibrating member 52, and the volume of the second cavity 6 is not greater than half the volume of the third cavity 10.

[0039] The mass block 53 is positioned away from the first cavity 1 on the vibrating element 52. side The distance H2 from the lower surface of the mass block 533 to the second housing 3, and the thickness h1 of the mass block 53, H2≤1 / 2h1.

[0040] In this embodiment, the volume of the second cavity 6 is divided into two second cavities 6 and a third cavity 10, thereby reducing the volume of the cavities above and below the vibration component 5 and improving the sensitivity.

[0041] Example 3: As shown in the attached document Figure 4 As shown, the structure is the same as in Embodiment 1, except that: the first housing 1 includes an electrical connection board 7, and a microphone assembly is provided on the first housing 1. The microphone assembly includes a MEMS 8 and an ASIC 9, and the microphone assembly is electrically connected to the circuit board 2 through the electrical connection board 7.

[0042] As attached Figure 5-7 As shown, the first housing 1 itself is used as an electrical connection board. The first housing 1 is provided with a microphone assembly, which includes MEMS8 and ASIC9, that is, different schemes of MEMS8 and ASIC9 being located at different positions on the first housing 1.

[0043] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A bone conduction microphone, comprising a first shell, a circuit board arranged at an opening of the first shell, and a second shell arranged at an outer periphery of the first shell, wherein a first cavity is formed between the second shell, the circuit board and the first shell, characterized in that: The first shell is provided with a vibration assembly outside the first cavity, and a second cavity is formed between the vibration assembly and the first shell, and the volume of the second cavity is not more than one third of the volume of the first cavity.

2. The bone conduction microphone of claim 1, wherein: The vibration assembly comprises a support provided on the first shell, and a vibration piece is provided at the end of the support away from the first shell, and a mass block is provided on the vibration piece, and the support, the vibration piece and the first shell form the second cavity.

3. The bone conduction microphone of claim 2, wherein: The mass block is provided on the side of the vibration piece close to the first shell, the distance from the upper surface of the mass block to the first shell is H1, and H1≤1 / 2h1.

4. The bone conduction microphone of claim 2, wherein: The end of the support away from the first shell is connected with the second shell, a third cavity is formed between the support, the second shell and the vibration piece, and the volume of the second cavity is not more than half of the volume of the third cavity.

5. A microphone according to claim 4, characterised in that: The mass block is provided on the side of the vibration piece away from the first cavity, and the distance from the lower surface of the mass block to the second shell is H2, and H2≤1 / 2h1.

6. The bone conduction microphone of any one of claims 2-5, wherein: The vibration piece is a diaphragm or an FPC soft board.

7. The bone conduction microphone of any one of claims 2-5, wherein: The first shell is a metal shell.

8. The bone conduction microphone of claim 7, wherein: The second shell is a metal shell.

9. The bone conduction microphone of claim 1, wherein: The first shell is provided with a microphone assembly, and the microphone assembly comprises a MEMS and an ASIC.

10. The bone conduction microphone of claim 9, wherein: The first shell comprises an electric connection plate, and the microphone assembly is electrically connected with the circuit board through the electric connection plate.

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