Directional microphone and product processing method based on the microphone

Abstract

An embodiment of this specification provides a directional microphone. The directional microphone at least includes a diaphragm and a first component located on the back side of the diaphragm; the first component has a first acoustic impedance that matches the target acoustic impedance, so that when the directional microphone is deployed in the target device, the target directivity is achieved; the target acoustic impedance includes the acoustic impedance corresponding to the target device; the first acoustic impedance is obtained by adjusting at least one part in the first component. This solution can effectively reduce the influence of the acoustic impedance corresponding to the overall structure of the target device on its own directivity performance, and obtain a microphone product with better directivity performance.

Description

Technical Field

[0001] The embodiments of this specification relate to the technical field of acoustic signal processing, and specifically, to a directional microphone and a product processing method based on this microphone. Background Art

[0002] The directivity of a microphone (i.e., a microphone, also known as a mic) refers to its ability to pick up sounds from different directions in space, which is one of the important performances of a microphone.

[0003] Currently, in some product design solutions for microphones, for the directivity test of the microphone, most are carried out in an ideal experimental environment, resulting in a significant deviation between the directivity of the designed microphone in the actual application environment and the target directivity, making it difficult to achieve the expected sound pickup performance.

[0004] Therefore, how to make the directivity performance of the microphone closer to the expectation has become one of the technical problems to be solved in this field. Summary of the Invention

[0005] This specification describes a directional microphone and a product processing method based on this microphone. By adjusting the first acoustic impedance possessed by the microphone itself to match the acoustic impedance generated by the target device, the influence of the target device on the directivity of the mic is offset.

[0006] In a first aspect, the embodiments of this specification provide a directional microphone deployed on a target device. The directional microphone at least includes a diaphragm and a first component located on the back side of the diaphragm; the first component has a first acoustic impedance that matches the target acoustic impedance, so that the directional microphone reaches the target directivity when deployed on the target device; the target acoustic impedance includes the acoustic impedance corresponding to the target device; the first acoustic impedance is obtained by adjusting at least one part in the first component.

[0007] In one embodiment, the first component includes a first sound inlet surface; the first acoustic impedance is obtained by adjusting the first sound inlet surface.

[0008] In one embodiment, the first acoustic impedance is obtained by adjusting the material property parameters of the first sound inlet surface; the material property parameters include any one or any combination of the sound absorption coefficient, porosity, and air permeability.

[0009] In one embodiment, the material of the first sound inlet surface is a fabric with mesh holes; the first acoustic impedance is obtained by adjusting the material property parameters of the fabric.

[0010] In one embodiment, the air permeability of the fabric is less than 900 mm / s.

[0011] In one embodiment, the air permeability of the fabric is 180 - 220 mm / s.

[0012] In one embodiment, the directional microphone is an electret condenser microphone ECM. The first component includes a first sound inlet surface and a back plate, and the back plate is disposed between the first sound inlet surface and the diaphragm; the first acoustic impedance is obtained by adjusting the back plate.

[0013] In one embodiment, at least one sound inlet hole is formed on the back plate; the first acoustic impedance is obtained by adjusting at least one sound inlet hole on the back plate.

[0014] In one embodiment, the first acoustic impedance is obtained by adjusting the number and / or size of at least one sound inlet hole.

[0015] In one embodiment, the first component further includes a rear chamber, and the rear chamber is disposed between the diaphragm and the back plate; the first acoustic impedance is further obtained by adjusting the rear chamber.

[0016] In one embodiment, the directional microphone further includes a second component located on the front side of the diaphragm; the second component has a second acoustic impedance matching the target acoustic impedance, so that the directional microphone further achieves the target directivity when deployed in the target device; the second acoustic impedance is obtained by adjusting at least one part in the second component.

[0017] In a second aspect, an embodiment of the present specification further provides a sound pickup device, and the sound pickup device includes the directional microphone described in any one of the above.

[0018] In a third aspect, an embodiment of the present specification further provides a conference phone device, and the conference phone device includes the directional microphone described in any one of the above.

[0019] In a fourth aspect, an embodiment of the present specification further provides a mobile terminal, and the mobile terminal includes the directional microphone described in any one of the above.

[0020] In a fifth aspect, an embodiment of the present specification further provides a recording device, and the recording device includes the directional microphone described in any one of the above.

[0021] In a sixth aspect, an embodiment of the present specification further provides a portable wearable device, which supports voice recognition, voice call and / or video call, and includes the directional microphone described in any one of the above.

[0022] In a seventh aspect, an embodiment of the present specification further provides an IoT device, which at least supports voice acquisition and includes the directional microphone described in any one of the above.

[0023] In an eighth aspect, an embodiment of the present specification further provides a smart home device that at least supports voice collection and includes a directional microphone as described in any one of the above.

[0024] In a ninth aspect, an embodiment of the present specification further provides a transportation device that at least supports voice collection and includes a directional microphone as described in any one of the above.

[0025] In a tenth aspect, an embodiment of the present specification further provides a product processing method based on a directional microphone. The directional microphone is deployed on a target device and at least includes a diaphragm and a first component located on the back side of the diaphragm;

[0026] The method includes: adjusting at least one part in the first component until the first component has a first acoustic impedance that matches the target acoustic impedance, so that the directional microphone achieves a target directivity when deployed on the target device; the target acoustic impedance includes the acoustic impedance corresponding to the target device.

[0027] In one embodiment, adjusting at least one part in the first component until the first component has a first acoustic impedance that matches the target acoustic impedance includes:

[0028] Testing the first directivity corresponding to the directional microphone when deployed on the target device; according to the difference between the first directivity and the target directivity, adjusting at least one part in the first component in the direction of reducing the difference until the difference between the first directivity and the target directivity is lower than a predetermined threshold condition, then it is determined that the current first component has a first acoustic impedance that matches the target acoustic impedance.

[0029] In one embodiment, the first component includes a first sound inlet surface; adjusting at least one part in the first component includes: adjusting the first sound inlet surface.

[0030] In one embodiment, adjusting the first sound inlet surface includes adjusting the material property parameters of the first sound inlet surface; the material property parameters include any one or any combination of the sound absorption coefficient, porosity, and air permeability.

[0031] In one embodiment, the material of the first sound inlet surface is a fabric with mesh holes; adjusting the first sound inlet surface includes: adjusting the material property parameters of the fabric.

[0032] In one embodiment, the air permeability of the fabric is less than 900 mm / s.

[0033] In one embodiment, the air permeability of the fabric is 180 - 220 mm / s.

[0034] In one embodiment, the directional microphone is an electret condenser microphone ECM. The first component includes a first sound inlet surface and a back plate, and the back plate is disposed between the first sound inlet surface and the diaphragm; adjusting at least one part in the first component includes: adjusting the back plate.

[0035] In one embodiment, at least one sound inlet hole is formed on the back plate; adjusting the back plate includes: adjusting at least one sound inlet hole on the back plate.

[0036] In one embodiment, adjusting at least one sound inlet hole on the back plate includes: adjusting the number and / or size of at least one sound inlet hole.

[0037] In one embodiment, the first component further includes a rear chamber, and the rear chamber is disposed between the diaphragm and the back plate; adjusting at least one part in the first component further includes: adjusting the rear chamber.

[0038] In one embodiment, the directional microphone further includes a second component located on the front side of the diaphragm; the method further includes: adjusting the second component to obtain a second acoustic impedance that matches the target acoustic impedance, so that the directional microphone further achieves the target directivity when deployed in the target device.

[0039] Using the microphone-based product parameter processing method provided in the embodiments of the present specification, by adjusting the acoustic properties of at least one part located on the back side of the microphone to have a first acoustic impedance that matches the target acoustic impedance generated by the target device correspondingly, that is, by changing the acoustic properties on the back side of the microphone to offset the influence of the hardware structure of the target device on the directivity of the microphone, so that after the microphone is installed in the target device, it still maintains the directivity performance that meets the design expectations. Description of the Drawings

[0040] In order to more clearly illustrate the technical solutions of the multiple embodiments disclosed in this specification, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only the multiple embodiments disclosed in this specification. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0041] Figure 1 Shows the corresponding directivity test result diagram of the microphone assembled in the target device before adjustment;

[0042] Figure 2 Shows the cross-sectional view of the microphone in one embodiment of this specification;

[0043] Figure 3 Shows the schematic acoustic structure diagrams corresponding to the back side of the microphone and the overall structure of the target device in one embodiment of this specification;

[0044] Figure 4 shows an acoustic impedance equivalent diagram of the acoustic structures respectively corresponding to the back side of the microphone and the overall structure of the target device in an embodiment of this specification;

[0045] Figure 5 shows a schematic internal three-dimensional structure diagram (not the overall structure) of the target device with multiple microphones installed in an embodiment of this specification;

[0046] Figure 6 shows a corresponding directivity test result diagram of the microphone (after adjustment) assembled in the target device in an embodiment of this specification. Detailed implementation manners

[0047] The following describes multiple embodiments disclosed in this specification with reference to the accompanying drawings.

[0048] During the product R & D process, the inventors found that in the structural designs of some existing directional microphones, the influence of the acoustic impedance formed by the environment outside the microphone on the directivity of the microphone in actual applications was not considered. Specifically, the microphone (hereinafter or simply referred to as mic) monomer can achieve the expected directivity performance in the test environment. However, after the mic is installed in the target device, the overall structure of the target device will form a certain acoustic impedance, and this part of the acoustic impedance will affect the directivity of the microphone. Most of the existing microphones under the current technology fail to discover this influence during product design and also fail to make adjustments for this influence.

[0049] For example, directivity tests are respectively carried out in the state of the mic monomer and the overall state after being installed in the target device. Exemplarily, the mic to be measured is a cardioid directional mic, and the target device is a conference phone device. In the test environment, it is assumed that the sound source emits sound wave signals with frequencies of 315 Hz, 500 Hz, 1 kHz, 3.15 kHz, and 5 kHz respectively, and a test point is arranged every 10° within a 360° range around the object to be measured, and the ability of the mic to pick up the sound wave signals is tested from all directions. The directivity test results corresponding to the state when the mic is not installed in the sound pickup device are referred to Figure 1 as shown, where Figure 1 the multiple straight lines radiating from the center of the circle are the reference lines corresponding to the respective angle markings; the circles marked with the numbers "0", "-10", "-20", and "-30" represent the reference lines corresponding to the sound wave signals of 0 dB (decibel), -10 dB, -20 dB, and -30 dB emitted by the test sound source respectively. The multiple irregular solid curves shown based on the above straight reference lines and circular reference lines are the directivity curves of the mic at each frequency. It can be seen that the directivity curve at this time is close to the ideal cardioid directivity.

[0050] In a situation where the acoustic wave signal emitted by the sound source, the layout and quantity of the test points are completely the same in the test environment, the mic is installed in the sound pickup device and then tested. The measured directivity curves are as shown by the multiple dotted curves in Figure 1 . From this Figure 1 , it can be clearly seen that after the mic is installed in the sound pickup device, there are obvious differences in the shapes of the dotted curve and the solid curve. The shape of the dotted curve significantly deviates from the expected heart shape and is closer to a supercardioid shape, failing to meet the original heart-shaped directivity requirement. It can be seen that the heart-shaped directivity mic with relatively good original directivity performance has its directivity significantly affected after being installed in the sound pickup device.

[0051] In view of this, this specification discloses a directional microphone and a product processing method based on this microphone, which adjusts the acoustic impedance of the mic itself to match the external acoustic impedance. In the solution disclosed in this specification, when the mic is initially designed, the target environment to be applied is first determined, that is, the target device is determined. According to the external acoustic impedance corresponding to the target device, the structure of the mic itself is adaptively adjusted. For example, at least one component on the back side of the mic itself is adjusted to have a first acoustic impedance to match the target acoustic impedance generated by the actual application environment, so that the microphone can adapt to the actual application environment and still achieve the expected directivity after being assembled into the target device. In the embodiments of this specification, the target device includes various devices that can install the microphone. For example, the target device may include conference phone devices, terminal devices, microphones, etc.

[0052] Specifically, the directional microphone provided by an embodiment of this specification is shown in Figure 2 . The microphone 11 includes a diaphragm 111 and a first component located on the back side of the diaphragm. The first component may include at least one component on the back side of the diaphragm. For example, it may include a first sound inlet surface 112, a back plate 114, etc. The first component has a first acoustic impedance that matches the target acoustic impedance.

[0053] In the embodiments of this specification, for the convenience of understanding, taking the diaphragm 111 as the boundary, the overall structure of the microphone is described from the perspectives of the front side and the back side. The part located on the back side is defined as the first component. For example, Figure 2 each component within the dotted box marked with the text "back side" in Figure 2Each component within the dashed box with the front-side text marker constitutes the second component. The second component includes at least a second in-sound surface 113. In the directional microphone design solution provided in this specification, in most embodiments, only the acoustic impedance formed corresponding to the first component on the back side is adjusted. It should be noted that this description method is only for easy understanding and does not actually split the structure of the microphone into the first component and the second component.

[0054] The first acoustic impedance, including the acoustic impedance corresponding to at least one component in the first component on the back side of the diaphragm in the microphone, is used to represent the combined effect of the acoustic capacitance, acoustic resistance, and acoustic reactance structures corresponding to the first component on the back side of the diaphragm in the microphone on the acoustic wave signal. In one embodiment, the first acoustic impedance is the acoustic impedance formed by at least one type of component on the back side of the microphone on the acoustic wave signal passing through the first in-sound surface. Correspondingly, the target acoustic impedance includes the acoustic impedance corresponding to the target device, that is, the acoustic impedance formed corresponding to the overall structure of the target device (excluding the microphone) when the microphone is installed in the target device. The target acoustic impedance is used to represent the combined effect of various acoustic capacitance, acoustic resistance, and acoustic reactance structures in the overall structure of the sound pickup device on the acoustic wave signal.

[0055] For example, refer to Figure 3 , the rear chamber in the microphone forms the first acoustic capacitance Ca1, the first in-sound surface is a fabric with mesh holes, such as a mesh cloth, and this mesh cloth and the back plate together form the first acoustic resistance Ra1 and the first acoustic reactance La1. Exemplarily, the shape of the overall structure of a sound pickup device is as shown in Figure 3 , which has two cavities with acoustic capacitance properties and multiple acoustic channels (acoustic reactances), forming the second acoustic capacitance Ca2, the third acoustic capacitance Ca3, and the second acoustic reactance La2, the third acoustic reactance La3, and the fourth acoustic reactance La4 respectively.

[0056] Refer to Figure 4 as shown, Figure 4 shows the acoustic impedance equivalent diagram of the acoustic structures corresponding to the back side of the microphone and the overall structure of the target device respectively. Among them, La1 and Ra1 determine the first acoustic impedance corresponding to the microphone, and the second acoustic capacitance Ca2, the third acoustic capacitance Ca3, and the second acoustic reactance La2, the third acoustic reactance La3, and the fourth acoustic reactance La4 determine the target acoustic impedance corresponding to the overall structure of the sound pickup device. For the diaphragm, the first acoustic impedance and the target acoustic impedance constitute the combined acoustic impedance to the external acoustic wave signal of the sound pickup device. This combined acoustic impedance is also the Figure 4 output equivalent impedance shown in. It should be noted that Figure 4 using the capacitance symbol to represent acoustic capacitance, the resistance symbol to represent acoustic resistance, and the inductance to represent acoustic reactance in is only for easy understanding and does not represent the actual product structure, and is not a limitation on the actual product structure.

[0057] In the embodiments of this specification, specifically, whether the first acoustic impedance matches the target acoustic impedance is determined by whether the target directivity performance can be obtained after the microphone is installed in the target device. That is, if the microphone with the first acoustic impedance can achieve the target directivity performance after being applied to the target device, it is considered that the first acoustic impedance matches the target device; if there is a large deviation from the target directivity, it is considered unmatched. The target directivity is the directivity that is expected to be achieved and meets the expected requirements, such as cardioid, figure-eight directivity, etc.

[0058] The matching of the first acoustic impedance and the target acoustic impedance can enable, after the microphone is installed in the target device, the combined acoustic impedance formed by the first acoustic impedance and the target acoustic impedance on the back side of the diaphragm to meet the acoustic impedance requirements for the back side at the beginning of the directivity design, so as to compensate for the influence of the overall environment of the target device on the directivity of the microphone.

[0059] Specifically, at least one part in the first component can be adjusted to obtain the first acoustic impedance that matches the target acoustic impedance. In some embodiments, the following method can be used for adjustment:

[0060] Test the first directivity corresponding to the original unadjusted microphone deployed in the target device. According to the difference between the first directivity and the target directivity, adjust at least one part in the first component in the direction of reducing the difference until the difference between the first directivity and the target directivity is lower than a predetermined threshold condition, then it is determined that the current first component has the first acoustic impedance that matches the target acoustic impedance. For example Figure 1 the multiple irregular dotted curves in correspond to the first directivity, Figure 1 and the multiple irregular solid curves in correspond to the target directivity. By adjusting at least one part in the first component, the curve shape of the first directivity can be made closer to the curve shape of the target directivity.

[0061] In one embodiment, when adjusting at least one part in the first component, the adjustment direction can be determined first, that is, first determine whether the influence of the target acoustic impedance makes the combined acoustic impedance higher or lower than the original acoustic impedance level. If it is higher, then lower the first acoustic impedance; if it is lower, then raise the first acoustic impedance, so that the combined acoustic impedance is restored or closer to the proper acoustic impedance level. The original acoustic impedance level is the acoustic impedance on the back side of the original unadjusted microphone in an ideal test environment. For example, when the influence of the target acoustic impedance on the mic is to reduce the acoustic impedance level on the back side of the mic, then raise the first acoustic impedance; when the influence of the target acoustic impedance on the mic is to increase the acoustic impedance level on the back side, then lower the first acoustic impedance, so that the combined acoustic impedance is closer to the original acoustic impedance level.

[0062] Specifically, the adjustment of the first acoustic impedance is achieved by adjusting at least one component on the back side of the microphone. The adjustment of the component means changing the product parameters of the component so that the first component as a whole has the first acoustic impedance. The product parameters include various parameters that can affect the acoustic impedance, such as dimensional parameters, structural parameters, shape parameters, material property parameters, etc., that is, by adjusting the indirect parameters that affect the acoustic impedance to achieve the purpose of adjusting the acoustic impedance. The material property parameters can include any one or any combination of the sound absorption coefficient, porosity, air permeability, etc. For example, the air permeability, porosity, etc. of the materials of each component are adjusted, or the number, size, etc. of the sound inlet holes are adjusted. All product parameters that can affect the acoustic impedance can be used as the adjustment targets. In one embodiment, the acoustic impedance of each component can also be directly adjusted, and the direct adjustment of the acoustic impedance requires accurate measurement of the acoustic impedance of each component as a prerequisite. In most embodiments, the dimensional parameters and material property parameters are easier to adjust and more practical.

[0063] It should be noted that the adjustment of at least one component in the first component includes the adjustment of any one or any combination of multiple components in the first component.

[0064] In one embodiment, the first sound inlet surface and / or the back plate are adjusted. The material of the first sound inlet surface is a fabric with mesh holes, and the material property parameters of the fabric can be adjusted. For example, the air permeability of the fabric is adjusted. Tests have shown that when the target device is determined, when the air permeability of the fabric is 900 mm / s, after the corresponding microphone is installed in the target device, the directivity performance significantly deviates from the expectation. The air permeability of the fabric is adjusted to be less than 900 mm / s until the target directivity is reached or approached. In a more specific embodiment, when the air permeability of the fabric is 180 - 220 mm / s, after the microphone is assembled into the whole sound pickup device, better directivity performance can be obtained. In another embodiment, other types of material property parameters such as the porosity of the fabric can also be adjusted so that the first component has the first acoustic impedance.

[0065] In the embodiments of this specification, the directional microphone is a unidirectional microphone or a bidirectional microphone, and can be a moving coil type, a capacitive type, an electret type, or a silicon micro-microphone, a laser microphone, etc. Some descriptions in the embodiments of this specification are only exemplary descriptions with the electret type as an example. For other types of microphones, specific adaptive settings can be made according to the technical means disclosed in the embodiments of this specification.

[0066] For example, refer to Figure 2As shown, when the microphone is an electret capacitance microphone (ECM), there is also a backplate 114 between the first sound inlet surface 112 and the diaphragm. The backplate 114 is provided with sound inlet holes 116 of a specified number and size. A rear chamber 115 is provided between the diaphragm and the backplate. In one embodiment, the first acoustic impedance can also be obtained by adjusting the backplate and / or the rear chamber. For example, changing the number and size of the sound inlet holes on the backplate, changing the distribution position of the sound inlet holes on the backplate, etc., changing the depth, shape, etc. of the rear chamber. Adjusting the rear chamber requires changing the original structure of the microphone, which is costly. In most embodiments, the first acoustic impedance is obtained by changing the product parameters of the backplate or the first sound inlet surface.

[0067] In most embodiments of this specification, when only the acoustic impedance of the structural components on the back side of the microphone is adjusted to match the target acoustic impedance of the overall structure of the target device, better directional pickup performance can be achieved. The overall structure of the target device also has a certain influence on the acoustic impedance of the front side of the microphone. Tests have shown that in most cases, this influence can be ignored, but it does not exclude that in other embodiments, the acoustic impedance of the structural components on the front side can also be adjusted. That is, in a few embodiments, at least one component in the second component located on the front side of the diaphragm is also adjusted to obtain a second acoustic impedance that matches the target acoustic impedance, so that when the microphone is deployed in the target device, it further matches the overall acoustic impedance of the pickup device and is closer to the target directivity.

[0068] It should be noted that in the embodiments of this specification, the distinction between the back side and the front side of the diaphragm is determined based on the target pickup direction of the microphone's directivity performance. For a unidirectional microphone, such as a cardioid directivity or a supercardioid directivity, the side facing the target pickup direction is the front side, and the side opposite to the target pickup direction is the back side. Or, the side corresponding to the direction where the pickup ability is suppressed is the back side. Correspondingly, Figure 2 the second sound inlet surface 113 shown in is the front sound inlet surface, that is, the side facing the target pickup direction, and the first sound inlet surface 112 is the back sound inlet surface, that is, the side opposite to the front sound inlet surface, which is generally used to suppress the entry of sound wave signals in the direction. For a bidirectional microphone, such as an 8-shaped directivity microphone, the target pickup directions are symmetric. In this case, the side facing the inside of the target device is regarded as the back side, and the side facing the outside of the target device is regarded as the front side.

[0069] To avoid confusion, further exemplary explanations are provided. Refer to Figure 5As shown in the figure, the target device is a conference phone device, and multiple microphones can be installed in this device. There is a support plate 12 in the target device, and multiple microphones 11 are symmetrically distributed along the edge of the support plate 12. At this time, the target sound pickup direction of the target device is 360° omnidirectional around. However, for a single microphone, its target sound pickup direction is only the pickup angle of its corresponding local range. The sound pickup direction of the whole target device cannot be used as a reference direction to distinguish the front and back of a single microphone, but the target sound pickup direction of the single microphone itself should be used as a reference. Therefore, in the Figure 5 shown situation, the surface facing the center direction of the sound pickup device is the back of the microphone (the first sound input surface 112), and the surface facing the outside direction of the sound pickup device is the front (the second sound input surface 113).

[0070] Refer to Figure 6 As shown in the figure, for the microphone obtained based on the above solution, the directivity test is carried out again. After the sound impedance of the mic is adjusted by using the solution disclosed in this specification, it is installed in the target device, and the directivity test is carried out on it. Still, sound wave signals with frequencies of 315 Hz, 500 Hz, 1 kHz, 3.15 kHz, and 5 kHz are used. Test points are arranged every 10° within the range of 360° around the object to be measured, and the sensitivity of the sound induction of the mic is tested from each direction. The test results are as Figure 6 shown. Figure 6 In the figure, the multiple irregular dotted curves are the adjusted directivity curves. It can be clearly seen from Figure 6 the figure that after adjusting the first sound impedance on the back side of the mic monomer itself to match the target sound impedance, to a certain extent, the directivity influence of the whole structure of the sound pickup device on the microphone is offset, and the obtained directivity is closer to the target directivity and approaches the ideal cardioid directivity.

[0071] The embodiment of this specification also provides a product processing method based on a directional microphone. This method is implemented based on a directional microphone, and this directional microphone at least includes a diaphragm and a first component located on the back side of the diaphragm. For the specific structure, refer to the above embodiment and will not be elaborated here.

[0072] Specifically, this method may include the following process: adjusting at least one part in the first component until the first component has a first sound impedance that matches the target sound impedance, so that when the microphone is deployed in the target device, the target directivity is achieved.

[0073] In one embodiment, adjusting at least one part in the first component until the first component has a first acoustic impedance matching the target acoustic impedance includes: testing the first directivity corresponding to when the test microphone is deployed on the target device, and according to the difference between the first directivity and the target directivity, adjusting at least one part in the first component in the direction of reducing the difference until the difference between the first directivity and the target directivity is lower than a predetermined threshold condition, then it is determined that the current first component has a first acoustic impedance matching the target acoustic impedance. For example, the first component includes a first sound inlet surface, and the first sound inlet surface is adjusted to obtain the first acoustic impedance. Adjusting the first sound inlet surface includes adjusting the material property parameters of the first sound inlet surface; the material property parameters include any one or any combination of the sound absorption coefficient, porosity, and air permeability. More specifically, the material of the first sound inlet surface is a fabric with mesh holes, and the material property parameters of the fabric can be adjusted, such as the air permeability.

[0074] In another embodiment, the backplate can also be adjusted. At least one sound inlet hole is provided on the backplate. For example, the number and / or size of the sound inlet holes on the backplate are adjusted. In one embodiment, the first component further includes a rear chamber, and the rear chamber can also be adjusted to adjust the acoustic impedance to obtain the first acoustic impedance.

[0075] In one embodiment, the microphone further includes a second component located on the front side of the diaphragm. Adjusting the second component to obtain a second acoustic impedance matching the target acoustic impedance so that when the microphone is deployed on the target device, the target directivity is further achieved. For the adjustment of the second acoustic impedance on the front side, reference can be made to the adjustment of the first acoustic impedance, which will not be elaborated here.

[0076] The directional microphone provided in the above embodiments of this specification can be applied not only to conference phones, but also to recording pens, mobile phones, TVs, intelligent Internet of Things (IOT) devices, etc.

[0077] The embodiments of this specification also provide a conference phone device. The conference phone device includes the directional microphone as described in any one of the above embodiments. For example, the conference phone device can be a product such as an octopus for multi-party conference phones.

[0078] The embodiments of this specification also provide a mobile terminal, such as a mobile phone, a tablet computer, a laptop computer, a portable POS machine, etc. The mobile terminal includes the directional microphone as described in any one of the above embodiments.

[0079] The embodiments of this specification also provide a recording device, such as a recording pen or a recorder. The recording device includes the directional microphone as described in any one of the above embodiments.

[0080] The embodiments of this specification also provide a portable wearable device, which supports voice recognition, voice call and / or video call, and includes a directional microphone as described in any one of the above embodiments. For example, the portable wearable device can be any one of devices such as headphones, smartwatches, smart bracelets, smart rings, smart sports shoes, and smart collars, necklaces, smart glasses, smart helmets, etc.

[0081] The embodiments of this specification also provide an IoT (Internet of Things) device, which at least supports voice collection, and the IoT device (i.e., the Internet of Things device) includes a directional microphone as described in any one of the above embodiments. For example, the IoT device can include smart home devices, wearable devices, travel devices, etc.

[0082] The embodiments of this specification also provide a smart home device, which at least supports voice collection and includes a directional microphone as described in any one of the above embodiments. The smart home device can include large household appliances (such as TVs, refrigerators, washing machines, air conditioners, etc.), small household appliances (such as electric pressure cookers, induction cookers, water dispensers, vacuum cleaners, routers, floor sweeping robots, fans, air purifiers, curtains, drying racks, etc.), as well as devices related to personal care and health such as hair dryers, razors, sphygmomanometers, and electrical appliances related to basic and safety such as lighting, door locks, cameras, and socket switches. For example, the directional microphone provided in the above embodiments can also be integrated on the integrated circuit inside the TV, or the sound pickup device provided in the above embodiments can also be set in various remote controls that support voice control.

[0083] The embodiments of this specification also provide a transportation device, which at least supports voice collection and includes a directional microphone as described in any one of the above embodiments. For example, the transportation device can include bicycles (including shared bicycles), electric vehicles, balance bikes, scooters, dash cams, in-vehicle air purifiers, etc.

[0084] The specific embodiments described above further elaborate on the objectives, technical solutions, and beneficial effects of multiple embodiments disclosed in this specification. It should be understood that the above is only the specific embodiments of multiple embodiments disclosed in this specification and is not used to limit the protection scope of multiple embodiments disclosed in this specification. Any modifications, equivalent replacements, improvements, etc. made on the basis of the technical solutions of multiple embodiments disclosed in this specification shall be included within the protection scope of multiple embodiments disclosed in this specification.

Claims

1. A directional microphone is deployed on a target device. The directional microphone at least includes a diaphragm and a first component located on the back side of the diaphragm. The first component has a first acoustic impedance that matches the target acoustic impedance. The first acoustic impedance and the target acoustic impedance form a combined acoustic impedance, so that when the directional microphone is deployed on the target device, a target directivity is achieved. The target acoustic impedance includes the acoustic impedance corresponding to the target device. The first acoustic impedance is obtained by adjusting at least one part in the first component.

2. The directional microphone according to claim 1, wherein, the first component includes a first sound inlet surface; the first acoustic impedance is obtained by adjusting the first sound inlet surface.

3. The directional microphone according to claim 2, wherein, the first acoustic impedance is obtained by adjusting the material property parameters of the first sound inlet surface. The material property parameters include any one or any combination of the sound absorption coefficient, porosity, and air permeability.

4. The directional microphone according to claim 3, wherein, the material of the first sound inlet surface is a fabric with mesh holes; the first acoustic impedance is obtained by adjusting the material property parameters of the fabric.

5. The directional microphone according to claim 4, wherein, the air permeability of the fabric is less than 900 mm / s.

6. The directional microphone according to claim 4, wherein, the air permeability of the fabric is 180 - 220 mm / s.

7. The directional microphone according to claim 1, wherein, the directional microphone is an electret condenser microphone ECM. The first component includes a first sound inlet surface and a back plate. The back plate is arranged between the first sound inlet surface and the diaphragm; the first acoustic impedance is obtained by adjusting the back plate.

8. The directional microphone according to claim 7, wherein, at least one sound inlet hole is formed on the back plate; the first acoustic impedance is obtained by adjusting at least one sound inlet hole on the back plate.

9. The directional microphone according to claim 8, wherein, the first acoustic impedance is obtained by adjusting the number and / or size of the at least one sound inlet hole.

10. The directional microphone according to claim 7, wherein, the first component further includes a rear chamber. The rear chamber is arranged between the diaphragm and the back plate; the first acoustic impedance is further obtained by adjusting the rear chamber.

11. The directional microphone according to any one of claims 1 - 10, wherein, the directional microphone further includes a second component located on the front side of the diaphragm; the second component has a second acoustic impedance that matches the target acoustic impedance, so that when the directional microphone is deployed on the target device, the target directivity is further achieved. The second acoustic impedance is obtained by adjusting at least one part in the second component.

12. A sound pickup device, wherein, the sound pickup device includes the directional microphone according to any one of claims 1 - 10.

13. A conference phone device, wherein, the conference phone device includes a directional microphone as described in any one of claims 1 - 10.

14. A mobile terminal, wherein, the mobile terminal includes a directional microphone as described in any one of claims 1 - 10.

15. A recording device, wherein, the recording device includes a directional microphone as described in any one of claims 1 - 10.

16. A portable wearable device, wherein, the portable wearable device supports any one or any combination of voice recognition, voice call, and video call, and includes a directional microphone as described in any one of claims 1 - 10.

17. An IoT device, wherein, the IoT device at least supports voice acquisition and includes a directional microphone as described in any one of claims 1 - 10.

18. A smart home device, wherein, the smart home device at least supports voice acquisition and includes a directional microphone as described in any one of claims 1 - 10.

19. A transportation device, wherein, the transportation device at least supports voice acquisition and includes a directional microphone as described in any one of claims 1 - 10.

20. A product processing method based on a directional microphone, the directional microphone being deployed in a target device and including at least a diaphragm and a first component located on the back side of the diaphragm; the method includes: Adjusting at least one part in the first component until the first component has a first acoustic impedance that matches a target acoustic impedance, and the first acoustic impedance and the target acoustic impedance form a combined acoustic impedance, so that when the directional microphone is deployed in the target device, a target directivity is achieved; the target acoustic impedance includes the acoustic impedance corresponding to the target device.

21. The method according to claim 20, wherein, adjusting at least one part in the first component until the first component has a first acoustic impedance that matches a target acoustic impedance includes: Testing the first directivity corresponding to when the directional microphone is deployed in the target device; According to the difference between the first directivity and the target directivity, adjusting at least one part in the first component in the direction of reducing the difference until the difference between the first directivity and the target directivity is lower than a predetermined threshold condition, then it is determined that the current first component has a first acoustic impedance that matches the target acoustic impedance.

22. The method according to claim 20, wherein, the first component includes a first sound inlet surface; adjusting at least one part in the first component includes: adjusting the first sound inlet surface.

23. The method according to claim 22, wherein, adjusting the first sound inlet surface includes adjusting the material property parameters of the first sound inlet surface; the material property parameters include any one or any combination of sound absorption coefficient, porosity, and air permeability.

24. The method according to claim 23, wherein, the material of the first sound inlet surface is a fabric with mesh holes; adjusting the first sound inlet surface includes: adjusting the material property parameters of the fabric.

25. The method according to claim 24, wherein, the air permeability of the fabric is less than 900 mm / s.

26. The method according to claim 24, wherein, the air permeability of the fabric is 180 - 220 mm / s.

27. The method according to claim 20, wherein, the directional microphone is an electret condenser directional microphone ECM, the first component includes a first sound inlet surface and a back plate, and the back plate is disposed between the first sound inlet surface and the diaphragm; adjusting at least one part in the first component includes: adjusting the back plate.

28. The method according to claim 27, wherein, at least one sound inlet hole is formed on the back plate; adjusting the back plate includes: adjusting at least one sound inlet hole on the back plate.

29. The method according to claim 28, wherein, adjusting at least one sound inlet hole on the back plate includes: adjusting the number and / or size of the at least one sound inlet hole.

30. The method according to claim 27, wherein, the first component further includes a rear chamber, and the rear chamber is disposed between the diaphragm and the back plate; adjusting at least one part in the first component further includes: adjusting the rear chamber.

31. The method according to any one of claims 20 - 30, wherein, the directional microphone further includes a second component located on the front side of the diaphragm; the method further includes: adjusting the second component to obtain a second acoustic impedance matching the target acoustic impedance, so that when the directional microphone is deployed in the target device, the target directivity is further achieved.

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