Array microphone

Abstract

An array microphone, comprising: a housing provided with an opening; a first circuit board provided in the housing; a plurality of microphones provided on the first circuit board; and a mesh enclosure covering the opening and provided with a plurality of mesh holes, wherein the area of the mesh enclosure is greater than or equal to that of the first circuit board, and the aperture ratio of the mesh enclosure = the sum of the areas of the mesh holes in the projection area of the first circuit board on the mesh enclosure / the area of the first circuit board, and the aperture ratio is greater than or equal to 50% and less than or equal to 70%. In the array microphone provided by the present application, when the aperture ratio is greater than or equal to 50% and less than or equal to 70%, both the pickup effect of the microphone and the strength of the mesh enclosure can be considered, and the frequency response curve consistency of the plurality of microphones can be ensured.

Description

Array microphone Technical Field

[0001] This application relates to an array microphone, and more particularly to a non-desktop array microphone for enhancing human voice pickup. Background Technology

[0002] In multi-person remote conferencing and video conferencing scenarios, microphones are placed on the table close to the speaker to pick up their voice. Typically, each speaker has a microphone in front of them. While this avoids people moving around and improves the efficiency of multi-person remote conferencing and video conferencing, it also makes the table more cluttered. Furthermore, microphones pick up desktop noise (e.g., the sound of papers turning, pens writing, and electronic devices being picked up or placed on the table). Therefore, usually only the microphone in front of the speaker is kept on, while the others are turned off. However, when two or more speakers are conversing, even with multiple microphones on, it is still possible to pick up a significant amount of desktop noise.

[0003] One existing improvement is to provide an array microphone that can be mounted on the ceiling or wall, which saves desktop space (avoiding desktop clutter) and also avoids the microphone picking up noise on the desktop. However, this array microphone is far from the speaker, which causes white noise (e.g., random signals in electronic devices, airflow) to affect its accuracy in picking up human voices.

[0004] Summary of the Invention

[0005] In view of the problems existing in the background art, this application provides an array microphone, including:

[0006] A shell with an opening;

[0007] A first circuit board disposed within the housing;

[0008] Multiple microphones disposed on the first circuit board; and

[0009] A mesh cover with multiple mesh openings is applied over the opening. The area of ​​the mesh cover is greater than or equal to the area of ​​the first circuit board. The opening ratio of the mesh cover is equal to the sum of the mesh opening areas of the projection area of ​​the first circuit board on the mesh cover / the area of ​​the first circuit board, wherein 50% ≤ opening ratio ≤ 70%.

[0010] In some embodiments of this application, every two microphones form a microphone unit, and each microphone unit has two independent pickup holes.

[0011] In some embodiments of this application, there are a total of 64 microphone units, of which 1 microphone unit is located at the center of the first circuit board, 3 microphone units are evenly arranged on a first annular strip with a radius of 20 cm, 6 microphone units are evenly arranged on a second annular strip with a radius of 50 cm, 12 microphone units are evenly arranged on a third annular strip with a radius of 100 cm, 18 microphone units are evenly arranged on a fourth annular strip with a radius of 180 cm, and 24 microphone units are evenly arranged on a fifth annular strip with a radius of 255 cm.

[0012] In some embodiments of this application, the array microphone includes a dustproof mesh covering the inside of the mesh cover.

[0013] In some embodiments of this application, the dustproof net is a nylon net.

[0014] In some embodiments of this application, the array microphone includes a microphone dust cover disposed on the first circuit board and covering each of the microphone units.

[0015] In some embodiments of this application, the array microphone includes support foam disposed between the first circuit board and the mesh cover.

[0016] In some embodiments of this application, the array microphone includes a light panel disposed inside the housing; a light guide disposed on the housing, wherein light-shielding cotton is disposed on the contact surface between the light guide and the housing, and the light guide contains 4g / kg of light-diffusing powder.

[0017] In some embodiments of this application, the array microphone includes a rear cover plate disposed on the housing, and a receiving cavity is formed between the rear cover plate and the housing; a second circuit board is disposed on the rear cover plate and located in the receiving cavity via a heat sink, a chip is disposed on the second circuit board, and thermally conductive silicone is disposed on the contact surface between the heat sink and the rear cover plate and the contact surface between the chip and the heat sink.

[0018] In some embodiments of this application, the array microphone includes a lanyard disposed on the rear cover; and a retractable rope with one end connected to the lanyard and the other end fixed to the ceiling.

[0019] In theory, the best state for microphone pickup is to be completely exposed to the environment without any obstruction. However, complete exposure can significantly impact a microphone's reliability and lifespan (e.g., exposure to airborne dust, water vapor, and direct impacts). Therefore, a mesh cover (usually made of aluminum) is needed to protect the microphone. On one hand, a larger mesh opening reduces microphone obstruction. On the other hand, a larger opening reduces the mesh's strength (poorer mechanical properties), making it more susceptible to deformation from impacts. Therefore, a mesh opening of 50% ≤ opening ≤ 70% balances microphone pickup performance with mesh strength and ensures consistent frequency response curves across multiple microphones. Attached Figure Description

[0020] Figure 1 is an exploded view of an array microphone provided in an embodiment of this application;

[0021] Figure 2 is an assembly diagram (front view) of the array microphone shown in Figure 1;

[0022] Figure 3 shows the assembly diagram (back side) of the array microphone shown in Figure 1;

[0023] Figure 4 is a schematic diagram of the array microphone shown in Figure 1 installed on the ceiling;

[0024] Figure 5 is a partial sectional view of the shell;

[0025] Figure 6 is a schematic diagram of multiple microphone units arrayed on the first circuit board;

[0026] Figure 7 is another partial sectional view of the shell;

[0027] Figure 8 is a partial sectional view of the rear cover;

[0028] Figure 9 shows the measured frequency response curve of the microphone unit (with a mesh opening rate of 50%).

[0029] Figure 10 shows the measured frequency response curve of the microphone unit (with a mesh opening ratio of 25%).

[0030] Figure 11 shows the measured frequency response curve of the microphone unit (the mesh opening rate is 50%, and the dustproof mesh is made of nylon).

[0031] Figure 12 shows the measured frequency response curve of the microphone unit (the mesh opening rate is 50%, and the dustproof mesh is made of non-woven fabric).

[0032] Explanation of reference numerals in the attached drawings: Array microphone 100; Housing 10; Opening 10a; Front shell 11; Rear shell 12; Rear cover 13; Hanging ring 14; Retractable rope 15; First circuit board 20; Microphone 30; Microphone unit 30a; Microphone dustproof mesh 31; Mesh cover 40; Dustproof mesh 41; Supporting foam 42; Light board 50; Light guide 51; Light-blocking cotton 52; Second circuit board 60; Heat sink 61; Chip 62; Thermal conductive silicone 63; Power board 70. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] As shown in Figures 1-6, one embodiment of this application provides an array microphone 100, mainly including a housing 10, a first circuit board 20, multiple microphones 30, and a mesh cover 40. The housing 10 has an opening 10a, the first circuit board 20 is disposed within the housing 10, the multiple microphones 30 are disposed on the first circuit board 20, and the mesh cover 40, having multiple mesh openings, covers the opening 10a. The area of ​​the mesh cover 40 is greater than or equal to the area of ​​the first circuit board 20. The aperture ratio of the mesh cover 40 is equal to the sum of the mesh opening areas within the projection area of ​​the first circuit board on the mesh cover / the area of ​​the first circuit board, where 50% ≤ aperture ratio ≤ 70%.

[0035] In this embodiment, the housing 10 includes a front shell 11 and a rear shell 12 that are fixedly connected by screws. A first circuit board 20 is disposed inside the housing 10 and fixed to the rear shell 12 by screws. An opening 10a is formed on the front shell 11, and a mesh cover 40 is fixed to the front shell 11 by screws and covers the opening 10a.

[0036] In other embodiments, the front shell 11 and the rear shell 12 can be fixedly connected to each other by means of riveting, welding, bonding, etc. The mesh cover 40 can also be fixedly disposed on the front shell 11 by means of riveting, welding, bonding, etc.

[0037] Those skilled in the art should understand that, theoretically, the best state for microphone 30 to pick up sound is to be completely exposed to the environment without any obstruction. However, complete exposure of microphone 30 will greatly affect its reliability and service life (e.g., exposure to dust, water mist, and direct impact from external forces). Therefore, a mesh cover 40 is needed to protect microphone 30 (mesh cover 40 is generally made of aluminum sheet). On the one hand, the larger the opening ratio of mesh cover 40, the less it obstructs microphone 30. On the other hand, the larger the opening ratio of mesh cover 40, the lower its own strength (the worse its mechanical properties), and the more easily it is deformed after being impacted by external forces. Therefore, with an opening ratio of 50% ≤ opening ratio ≤ 70%, it is possible to balance the sound pickup effect of microphone 30 and the strength of mesh cover 40, and to ensure the consistency of frequency response curves of multiple microphones 30.

[0038] Referring specifically to Figure 6, further, every two microphones 30 form a microphone unit 30a, and each microphone unit 30a has two independent pickup holes.

[0039] Furthermore, there are a total of 64 microphone units 30a. One microphone unit 30a is located at the center of the first circuit board 20, three microphone units 30a are evenly arranged on a first annular strip with a radius of 20 cm, six microphone units 30a are evenly arranged on a second annular strip with a radius of 50 cm, twelve microphone units 30a are evenly arranged on a third annular strip with a radius of 100 cm, eighteen microphone units 30a are evenly arranged on a fourth annular strip with a radius of 180 cm, and twenty-four microphone units 30a are evenly arranged on a fifth annular strip with a radius of 255 cm.

[0040] Those skilled in the art should understand that existing array microphones can only handle audio signals with a high-frequency limit of approximately 8000 Hz and a low-frequency limit of approximately 500 Hz, resulting in insufficient audio quality for uplink speech. Improving the signal-to-noise ratio (SNR) is crucial for enhancing speech clarity and sound quality. To achieve effective sound pickup within a 5–7 meter range, array microphones need to improve the SNR by approximately 30 to 40 dB. Based on the relationship between sound wavelength λ, sound speed v (approximately 343 m / s), and frequency f (λ = v / f), and considering that the frequency range of human voice is 200–8000 Hz, the microphone array needs to be able to adapt to wavelengths of at least 4–170 cm. Based on this, microphone units 30a are arranged at the center of the first circuit board 20 and on annular bands with radii of 20 cm, 50 cm, 100 cm, 180 cm, and 255 cm to form differential directional beams, thereby optimizing sound pickup and reducing ambient noise interference by directional sound capture. This aims to meet the full-frequency pickup needs of human voices, ensuring that audio from low to high frequencies can be effectively captured. Furthermore, as shown in Figures 9 and 10, taking the outermost 16 microphone units 30a as an example (numbered 49-64), the prototype with a 50% opening ratio of the mesh cover 40 exhibits good consistency in its frequency response curve, while the prototype with a 25% opening ratio of the mesh cover 40 exhibits poor consistency in its frequency response curve.

[0041] Referring again to Figures 1 and 5, the array microphone 100 further includes a dustproof mesh 41 covering the inside of the mesh cover 40.

[0042] Furthermore, the dustproof net 41 is made of nylon.

[0043] In this embodiment, the dustproof mesh 41 is glued to the inside of the mesh cover 40 by spraying adhesive. As shown in Figures 11 and 12, taking the outermost 16 microphone units 30a (numbered 49 to 64) as an example, for the prototype with an opening rate of 50% for the mesh cover 40, the frequency response curves are actually more consistent after the nylon mesh is glued on, but less consistent after the non-woven fabric is glued on.

[0044] Referring again to Figures 5 and 6, the array microphone 100 further includes a microphone dust cover 31 disposed on the first circuit board 20 and covering each microphone unit 30a.

[0045] Furthermore, the array microphone 100 includes a support foam 42 disposed between the first circuit board 20 and the mesh cover 40.

[0046] Those skilled in the art should understand that the microphone dust cover 31 can also be made of nylon mesh, just like the dust cover 41, which will not affect the frequency response consistency of the microphone unit 30a and can also play a further role in dust prevention. The supporting foam 42 can prevent the mesh cover 40 from collapsing into the interior of the housing 10 due to external impact, and has a protective function for the components located inside the housing 10.

[0047] Referring to FIG7, the array microphone 100 further includes a lamp plate 50 disposed inside the housing 10, a light guide 51 disposed on the housing 10, a light-shielding cotton 52 disposed on the contact surface between the light guide 51 and the housing 10, and the light guide 51 contains 4g / kg of light-diffusing powder.

[0048] In this embodiment, the lamp panel 50 and the rear shell 12 are fixedly connected by screws. The light guide 51 and the face shell 11 are also fixedly connected by screws, and the light-shielding cotton 52 is held in position by the light guide 51 and the face shell 11 from both sides.

[0049] In other embodiments, the lamp panel 50 and the rear shell 12, and the light guide 51 and the front shell 11 can be fixedly connected to each other by means of riveting, welding, bonding, etc. The light-blocking cotton 52 can be directly bonded to the front shell 11.

[0050] Those skilled in the art should understand that the light emitted by the light-emitting elements (e.g., LED beads) on the light panel 50 can be conducted to the outside of the housing 10 via the light guide 51, thereby indicating to the user whether the array microphone 100 is on or off. The light-blocking cotton 52 is used to fill the gap between the light guide 51 and the housing 11 to prevent light leakage.

[0051] Referring to Figure 8, the array microphone 100 further includes a rear cover 13 disposed on the housing 10, with a receiving cavity formed between the rear cover 13 and the housing 10. A second circuit board 60 is disposed on the rear cover 13 and located in the receiving cavity via a heat sink 61. A chip 62 is disposed on the second circuit board 60. Thermally conductive silicone 63 is disposed on the contact surface between the heat sink 61 and the rear cover 13, and on the contact surface between the chip 62 and the heat sink 61.

[0052] In this embodiment, both the rear cover 13 and the heat sink 61 are made of aluminum alloy, and the heat sink 61 is coated with nano-carbon, both of which have excellent heat dissipation performance. The second circuit board 60 is the main control board.

[0053] In this embodiment, a power board 70 is also provided in the cavity formed between the rear cover 13 and the housing 10. The power board 70 is connected to the second circuit board 60 via a flexible printed circuit board (FPC). The second circuit board 60 can have its own power supply module, thus eliminating the need for the power board 70. A wire-through hole is provided on the rear housing 12, and the second circuit board 60, the first circuit board 20, and the lamp board 50 are also interconnected after passing through the wire-through hole via a flexible printed circuit board.

[0054] Those skilled in the art should understand that the second circuit board 60 with chip 62 generates a large amount of heat. The selection of the heat sink affects the heat dissipation effect of the motherboard, the service life of the product, and the user experience (for example, the software defines 85°C as the over-temperature protection value of the chip, and the system will be forced to stop operating if the temperature is exceeded). The heat sink 61 (aluminum alloy sprayed with nano carbon, with a mass of about 181.5g) and the thermally conductive silicone 63 can direct the generated heat to the rear cover 13 side to avoid the chip 62 temperature from getting too high (for example, under normal circumstances, the chip temperature is controlled below 50°C), and at the same time prevent the heat from being conducted to the housing 10 side and reducing the performance of the first circuit board 20 and the microphone 30.

[0055] Furthermore, the array microphone 100 includes a lanyard 14 disposed on the rear cover 13, and a retractable rope 15 with one end connected to the lanyard 14 and the other end fixed to the ceiling.

[0056] During installation, a mesh cover 40, a dustproof mesh 41, and a light guide 51 are fixedly mounted on the front shell 11, forming the front shell assembly. A first circuit board 20 and a lamp board 50 are fixedly mounted on the rear shell 12, forming the rear shell assembly. A second circuit board 60, a heat sink 61, and a power board 70 are fixedly mounted on the rear cover 13, forming the rear cover assembly. The front shell assembly, rear shell assembly, and rear cover assembly are then connected to each other with screws, enabling modular installation and disassembly. Adjusting the length of the retractable rope 15 allows the array microphone 100 to remain flush with the rest of the ceiling, without affecting aesthetics.

[0057] In the description of this specification, the references to terms such as "certain embodiments," "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0058] In this application, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise expressly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can mean a fixed connection, a detachable connection, or an integral connection; "link" can mean a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application and are not restrictive. Although this application has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of this application do not depart from the spirit and scope of the technical solutions of this application, and should all be covered within the scope of the claims of this application.

Claims

1. An array microphone, characterized in that, include: A shell with an opening; A first circuit board disposed within the housing; Multiple microphones are mounted on the first circuit board; as well as A mesh cover with multiple mesh openings is applied over the opening. The area of ​​the mesh cover is greater than or equal to the area of ​​the first circuit board. The opening ratio of the mesh cover is equal to the sum of the mesh opening areas of the projection area of ​​the first circuit board on the mesh cover / the area of ​​the first circuit board, wherein 50% ≤ opening ratio ≤ 70%.

2. The array microphone according to claim 1, characterized in that: Each pair of microphones forms a microphone unit, and each microphone unit has two independent pickup holes.

3. The array microphone according to claim 2, characterized in that: There are a total of 64 microphone units. One microphone unit is located at the center of the first circuit board. Three microphone units are evenly arranged on a first annular strip with a radius of 20 cm. Six microphone units are evenly arranged on a second annular strip with a radius of 50 cm. Twelve microphone units are evenly arranged on a third annular strip with a radius of 100 cm. Eighteen microphone units are evenly arranged on a fourth annular strip with a radius of 180 cm. Twenty-four microphone units are evenly arranged on a fifth annular strip with a radius of 255 cm.

4. The array microphone according to claim 1, characterized in that, include: A dustproof net covering the inside of the mesh cover.

5. The array microphone according to claim 4, characterized in that: The dustproof net is made of nylon.

6. The array microphone according to claim 1, characterized in that, include: A microphone dust cover is disposed on the first circuit board and covers each of the microphone units.

7. The array microphone according to claim 1, characterized in that, include: Support foam is disposed between the first circuit board and the mesh cover.

8. The array microphone according to claim 1, characterized in that, include: The lamp panel is disposed inside the housing; A light guide is disposed on the housing, and light-shielding cotton is disposed on the contact surface between the light guide and the housing. The light guide contains 4g / kg of light-diffusing powder.

9. The array microphone according to claim 1, characterized in that, include: A rear cover plate is disposed on the housing, and a receiving cavity is formed between the rear cover plate and the housing; The second circuit board is mounted on the rear cover plate via a heat sink and is located within the receiving cavity. A chip is mounted on the second circuit board, and thermally conductive silicone is provided on the contact surface between the heat sink and the rear cover plate, and on the contact surface between the chip and the heat sink.

10. The array microphone according to claim 9, characterized in that, include: The lifting ring is provided on the rear cover plate; A retractable rope with one end connected to the lifting ring and the other end fixed to the ceiling.

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