A vibration sensor

Abstract

The embodiments of the present specification disclose a vibration sensing device, comprising: an acoustic transducer; a vibration assembly connected with the acoustic transducer, the vibration assembly is configured to transmit an external vibration signal to the acoustic transducer to generate an electrical signal, the vibration assembly comprises one or more groups of diaphragms and mass blocks, the mass blocks are physically connected to the diaphragms; the vibration assembly is configured to make the sensitivity of the vibration sensor greater than the sensitivity of the acoustic transducer within one or more target frequency bands.

Description

TECHNICAL FIELD

[0001] The present specification relates to the field of sensors, and in particular to a vibration sensor including a vibration assembly. BACKGROUND

[0002] A vibration sensor is an energy conversion device that converts a vibration signal into an electrical signal, and its uses include as a microphone (such as an air-conduction microphone, a bone-conduction microphone, etc.) or a monitoring device, etc. The vibration sensor can obtain data such as the amplitude and direction of vibration, and convert it into an electrical signal or other required form for further analysis and processing.

[0003] Sensitivity is an important performance indicator of a vibration sensor, and how to improve the sensitivity of a vibration sensor becomes a problem to be solved. SUMMARY

[0004] One of the embodiments of the present specification provides a vibration sensor, including: an acoustic transducer and a vibration assembly connected with the acoustic transducer. The vibration assembly is configured to transmit an external vibration signal to the acoustic transducer to generate a sound signal, and the vibration assembly includes one or more groups of diaphragms and mass blocks, the mass blocks being physically connected to the diaphragms; the vibration assembly is configured to make the sensitivity of the vibration sensor greater than the sensitivity of the acoustic transducer within one or more target frequency bands.

[0005] In some embodiments, the one or more groups of diaphragms and mass blocks are sequentially arranged along the vibration direction of the diaphragms; the distance between adjacent diaphragms in the vibration assembly is not less than the maximum amplitude of the adjacent diaphragms.

[0006] In some embodiments, in the vibration direction of the diaphragm, the projection area of the mass block is located within the projection area of the diaphragm.

[0007] In some embodiments, each group of diaphragms and mass blocks in the one or more groups of diaphragms and mass blocks corresponds to one target frequency band in the one or more different target frequency bands, so that the sensitivity of the vibration sensor is greater than the sensitivity of the acoustic transducer within the corresponding target frequency band.

[0008] In some embodiments, the resonance frequency of the one or more groups of diaphragms and mass blocks is less than the resonance frequency of the acoustic transducer so that the sensitivity of the vibration sensor is greater than the sensitivity of the acoustic transducer within the one or more target frequency bands.

[0009] In some embodiments, the difference between the resonance frequency of the one or more groups of diaphragms and mass blocks and the resonance frequency of the acoustic transducer is within 1 kHz-10 kHz.

[0010] In some embodiments, the resonance frequencies of at least two of the plurality of sets of diaphragm and mass are different.

[0011] In some embodiments, the resonance frequencies of the plurality of sets of diaphragm and mass differ by less than 2 kHz.

[0012] In some embodiments, the resonance frequencies of the plurality of sets of diaphragm and mass differ by no more than 1 kHz.

[0013] In some embodiments, the resonance frequencies of the one set and the plurality of sets of diaphragm and mass are within 1 kHz to 10 kHz.

[0014] In some embodiments, the resonance frequencies of the one set and the plurality of sets of diaphragm and mass are within 1 kHz to 5 kHz.

[0015] In some embodiments, the resonance frequencies of the one set and the plurality of sets of diaphragm and mass are related to a parameter of the diaphragm and / or the mass, the parameter comprising at least one of a modulus of the diaphragm, a volume of a cavity formed between the acoustic transducer and the diaphragm, a radius of the mass, a height of the mass, and a density of the mass.

[0016] In some embodiments, the modulus of the diaphragm is within 1 GPa to 10 GPa.

[0017] In some embodiments, the radius of the mass is within 500 pm to 3 mm.

[0018] In some embodiments, the vibration sensor has a frequency response curve with multiple resonance peaks under the action of the one set or the plurality of sets of diaphragm and mass.

[0019] In some embodiments, the vibration assembly further comprises a support structure for supporting the one set or the plurality of sets of diaphragm and mass, the support structure being physically connected to the acoustic transducer, the one set or the plurality of sets of diaphragm and mass being connected to the support structure.

[0020] In some embodiments, the support structure is made of a gas-impermeable material.

[0021] In some embodiments, in a direction perpendicular to a surface connected to the diaphragm and the mass, a projection area of the mass does not overlap with a projection area of the support structure.

[0022] In some embodiments, the mass is concentrically arranged with the diaphragm.

[0023] In some embodiments, the diaphragm is configured to allow air to pass through.

[0024] In some embodiments, among the plurality of diaphragms, the diaphragm farthest from the acoustic transducer is configured to be incapable of passing air.

[0025] In some embodiments, the diaphragm comprises a gas permeable membrane.

[0026] In some embodiments, the diaphragm comprises at least one of polytetrafluoroethylene, expanded polytetrafluoroethylene, polyethersulfone, polyvinylidene fluoride, polypropylene, polyethylene terephthalate, nylon, nitrocellulose, or mixed cellulose.

[0027] In some embodiments, the vibration assembly further comprises a limiting structure configured to make the distance between adjacent diaphragms in the vibration assembly no less than the maximum amplitude of the adjacent diaphragms.

[0028] In some embodiments, the acoustic transducer is a gas conduction microphone; the resonant frequency of the one or more target frequency bands is configured to be 1 kHz-10 kHz lower than the resonant frequency of the gas conduction microphone.

[0029] In some embodiments, the gas conduction microphone comprises a sound pickup hole, and the one or more groups of diaphragms and masses are arranged within the sound pickup hole parallel to the radial cross section of the sound pickup hole; or, are arranged outside the sound pickup hole.

[0030] In some embodiments, the mass does not contact the inner wall of the sound pickup hole.

[0031] One of the embodiments of the present specification provides a sound input device comprising any one of the above-mentioned vibration sensors. BRIEF DESCRIPTION OF DRAWINGS

[0032] The present specification will be further illustrated in the manner of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting, and in these embodiments, the same numbers represent the same structures, in which:

[0033] Figure 1 is a modular schematic diagram of a vibration sensor according to some embodiments of the present specification;

[0034] Figure 2 is a structural schematic diagram of a vibration sensor according to some embodiments of the present specification;

[0035] Figure 3 is a structural schematic diagram of a vibration sensor according to some embodiments of the present specification;

[0036] Figure 4 is a structural schematic diagram of a vibration assembly according to some embodiments of the present specification;

[0037] Figure 5 is a frequency response curve of a vibration sensor according to some embodiments of the present specification;

[0038] Figure 6 is a schematic diagram of a vibration sensor structure according to some embodiments of the present specification. DETAILED DESCRIPTION

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present specification, the drawings required to be used in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some examples or embodiments of the present specification, and for those skilled in the art, the present specification can also be applied to other similar scenarios without creative labor. It should be understood that these exemplary embodiments are only presented to enable those skilled in the art to better understand and implement the present application, and do not limit the scope of the present application in any way. Unless the context clearly indicates otherwise or otherwise stated, the same reference numbers in the drawings represent the same structures or operations.

[0040] As shown in the present specification and claims, unless the context clearly indicates otherwise or otherwise stated, the words "one", "a", "an", and / or "the" do not specifically refer to the singular, but can also include the plural. Generally speaking, the terms "comprise" and "include" only indicate the inclusion of the steps and elements explicitly identified, and these steps and elements do not constitute an exclusive list, and the method or device can also include other steps or elements. The term "based on" is "at least partially based on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment". The related definitions of other terms will be given in the following description.

[0041] In some embodiments, the vibration sensor as a microphone (such as an air conduction microphone, a bone conduction microphone, etc.), wherein the means for converting vibration into an electrical signal includes an acoustic transducer. Generally, there is only one resonance peak for a single acoustic transducer, and the acoustic transducer only has high sensitivity near the frequency of the resonance peak. In some embodiments, in order to improve the sensitivity of the vibration sensor, a plurality of acoustic transducers with different resonance peaks are arranged to increase the receiving frequency range and sensitivity, but increasing the number of acoustic transducers will cause the increase of the volume and manufacturing cost of the vibration sensor.

[0042] In view of this, the present specification relates to a vibration sensor that has a vibration assembly connected to an acoustic transducer such that the vibration sensor has a sensitivity greater than the acoustic transducer in one or more target frequency bands. The vibration sensor can be used to receive an external vibration signal and convert the vibration signal into an electrical signal that reflects sound information, where the external signal can include a mechanical vibration signal or an acoustic signal, etc. The vibration assembly can include one or more sets of diaphragms and masses, with the masses physically connected to the diaphragms. The vibration assembly is configured to cause the vibration sensor to have a sensitivity greater than the acoustic transducer in one or more target frequency bands.

[0043] As shown in Figure 1 , the vibration sensor 100 can include an acoustic transducer 120 and a vibration assembly 130. In some embodiments, the acoustic transducer 120 is connected to the vibration assembly 130, which is configured to transmit an external vibration signal to the acoustic transducer to generate an electrical signal. When a vibration occurs in the external environment, the vibration assembly 130 responds to the vibration of the external environment and transmits the vibration signal to the acoustic transducer 120, which then converts the vibration signal into an electrical signal. The vibration sensor 100 can be applied to a mobile device, a wearable device, a virtual reality device, an augmented reality device, etc., or any combination thereof. In some embodiments, the mobile device can include a smartphone, a tablet computer, a personal digital assistant (PDA), a gaming device, a navigation device, etc., or any combination thereof. In some embodiments, the wearable device can include a smart bracelet, a headset, a hearing aid, a smart helmet, a smart watch, smart clothing, a smart backpack, a smart accessory, etc., or any combination thereof. In some embodiments, the virtual reality device and / or the augmented reality device can include a virtual reality helmet, a virtual reality glasses, a virtual reality patch, an augmented reality helmet, an augmented reality glasses, an augmented reality patch, etc., or any combination thereof. For example, the virtual reality device and / or the augmented reality device can include Google Glass, Oculus Rift, Hololens, Gear VR, etc.

[0044] As shown in Figure 1 , the vibration assembly 130 includes a diaphragm 131 and a mass 132, where the mass 132 is physically connected to the diaphragm 131. The vibration assembly 130 is configured to cause the vibration sensor 100 to have a sensitivity greater than the acoustic transducer 120 in one or more target frequency bands.

[0045] In some embodiments, one or more sets of diaphragms 131 and masses 132 are arranged in sequence along the vibration direction of the diaphragm 131; the distance between adjacent diaphragms 131 in the vibration assembly 130 is not less than the maximum amplitude of the adjacent diaphragms 131. In some embodiments, the diaphragm 131 is configured to allow air to pass through.

[0046] In some embodiments, each set of diaphragm 131 and mass 132 corresponds to one of the one or more different target frequency bands, so that the sensitivity of the vibration sensor 100 in the corresponding target frequency band can be greater than the sensitivity of the acoustic transducer 120. In some embodiments, the sensitivity of the vibration sensor 100 with one or more sets of diaphragm 131 and mass 132 can be improved by 3dB-30dB compared to the sensitivity of the acoustic transducer 120 in the target frequency band. It should be noted that in some embodiments, the sensitivity of the vibration sensor 100 with one or more sets of diaphragm 131 and mass 132 can be improved by more than 30dB compared to the sensitivity of the acoustic transducer 120, such as when the multiple sets of diaphragm 131 and mass 132 have the same resonance peak.

[0047] In some embodiments, the method of measuring the sensitivity of the vibration sensor 100 and the acoustic transducer 120 can be: under a given acceleration excitation (such as 1g, g is the acceleration of gravity), the electrical signal of the device (such as -30dBV) is collected, and the sensitivity is -30dBV / g. In some embodiments, such as when the acoustic transducer 120 is an air-conducted microphone, the excitation source can be replaced by sound pressure when measuring the sensitivity, that is, the sound pressure in the specified frequency band is input as the excitation, and the electrical signal of the collection device is measured.

[0048] In some embodiments, the frequency response curve of the vibration sensor 100 under the action of one or more sets of diaphragm 131 and mass 132 can have multiple resonance peaks.

[0049] In some embodiments, the resonance frequencies of the plurality of sets of mass blocks 132 and diaphragms 131 are within 1 kHz to 10 kHz. In some embodiments, the resonance frequencies of the plurality of sets of mass blocks 132 and diaphragms 131 are within 1 kHz to 5 kHz. In some embodiments, the resonance frequencies of at least two sets of mass blocks 132 and diaphragms 131 in the plurality of sets of mass blocks 132 and diaphragms 131 are different. In some embodiments, the resonance frequencies of the plurality of sets of mass blocks 132 and diaphragms 131 differ by less than 2 kHz between adjacent resonance frequencies. In some embodiments, the resonance frequencies of the plurality of sets of mass blocks 132 and diaphragms 131 differ by no more than 1.5 kHz between adjacent resonance frequencies. In some embodiments, the resonance frequencies of the plurality of sets of mass blocks 132 and diaphragms 131 differ by no more than 1 kHz, such as 500 Hz, 700 Hz, or 800 Hz, between adjacent resonance frequencies. In some embodiments, the resonance frequencies of the plurality of sets of mass blocks 132 and diaphragms 131 differ by no more than 500 Hz between adjacent resonance frequencies.

[0050] In some embodiments, the diaphragm 131 can include a gas permeable membrane. Further description of the vibration assembly can be found in the detailed description of Figures 2-6 .

[0051] Figure 2 is a structural schematic diagram of a vibration sensor according to some embodiments of the present specification.

[0052] Figure 2 The vibration sensor 200 described in Figure 1 may be an embodiment of the vibration sensor 100 in . In some embodiments, the vibration sensor 200 includes an acoustic transducer 220 and a vibration assembly 230. The acoustic transducer 220 can include an air conduction microphone, also known as an air-conducted microphone, which can obtain the sound pressure changes in a sound pickup area (such as at the sound pickup hole 211) and convert them into electrical signals. For ease of description, hereinafter, all descriptions are made by way of air conduction microphones. It should be noted that in some other embodiments, the acoustic transducer can also be in other forms, such as a liquid microphone and a laser microphone.

[0053] Referring to Figure 2 , in some embodiments, the air conduction microphone includes a housing structure 210 and a sound pickup device 221. In some embodiments, the sound pickup device 221 can include a transducer in a form of a condenser, a piezoelectric, or the like according to the transduction principle, which is not limited in the present specification.

[0054] In some embodiments, the shell structure 210 can have a shape of a cuboid, a cuboid-like shape, a cylinder, a sphere, or any other shape. The shell structure 210 encloses a receiving space in which the sound pickup device 221 is disposed. In some embodiments, the sound pickup device 221 is physically connected to the shell structure 210, and the physical connection can include welding, clamping, bonding, or one-piece forming, without limitation. In some embodiments, the shell structure 210 can be made of a material with a certain hardness, so as to protect the sound pickup device 221 and internal components. In some embodiments, the material of the shell structure 210 can include one or more of metal, alloy material (such as aluminum alloy, chromium-molybdenum steel, scandium alloy, magnesium alloy, titanium alloy, magnesium-lithium alloy, nickel alloy, etc.), glass fiber or carbon fiber, and high polymer material (such as acrylonitrile-butadiene-styrene copolymer, polyvinyl chloride, polycarbonate, polypropylene, etc.).

[0055] In some embodiments, the shell structure 210 is provided with a sound pickup hole 211 for sound pickup. In some embodiments, the vibration assembly 230 is disposed near the sound pickup hole 211 of the shell structure 210. In some embodiments, the one or more sets of diaphragms and mass blocks are disposed outside the sound pickup hole. In some embodiments, the vibration assembly 230 is physically connected to the shell structure, and the physical connection can include welding, clamping, bonding, or one-piece forming, without limitation. It should be noted that in some embodiments, the one or more sets of diaphragms and mass blocks can also be disposed in the sound pickup hole in parallel to the radial cross section of the sound pickup hole, which will be described in detail below. Figure 5 Related description.

[0056] In some embodiments, when the vibration sensor 200 is used for air conduction sound pickup, when the external environment generates vibration (e.g., sound wave), the one or more sets of diaphragms and mass blocks on the diaphragms vibrate in response to the vibration of the external environment. Since the diaphragm can allow air to pass through, the vibration generated by the diaphragm and the mass block together with the external vibration signal (e.g., sound wave) can cause the sound pressure in the sound pickup hole 211 to change (or air vibration) so that the vibration signal is transmitted to the sound pickup device 221 through the sound pickup hole 211 to be converted into an electrical signal, thereby realizing the process of strengthening the vibration signal in one or more target frequency bands and converting it into an electrical signal. The target frequency band can be a frequency range corresponding to the resonance frequency (or harmonic frequency) of the one or more sets of diaphragms and mass blocks. For example, when the vibration sensor 200 is used as a microphone, the target frequency band can range from 200 Hz to 2 kHz. Specifically, in some embodiments, if the resonance frequency of the acoustic transducer is 2 kHz, the resonance frequency of the vibration assembly 230 can be configured to be 1 kHz.

[0057] In some embodiments, when the vibration sensor 200 is used for bone conduction sound pickup, a conductive housing can be provided outside the pickup hole 211. The acoustic transducer 220 and the conductive housing can form a receiving space, and one or more sets of diaphragms and mass blocks are disposed within the receiving space. In some embodiments, the vibration component (e.g., a vibrating element) can be physically connected to the housing. When the external environment vibrates, the vibration is received through the conductive housing and causes the vibration component to vibrate. The vibration of the vibration component can cause the air in the receiving space to vibrate. The vibration generated by the diaphragm and mass block, together with the vibration signal in the receiving space, is transmitted through the pickup hole 211 to the pickup device 221 and converted into an electrical signal.

[0058] like Figure 2 As shown, in some embodiments, the vibration sensor 200 includes three sets of diaphragms and mass blocks. Specifically, the three sets of diaphragms and mass blocks can have different resonant frequencies. Each set of diaphragms and mass blocks can resonate under the action of vibration at different frequencies in the external vibration signal, so that the sensitivity of the sound signal acquired by the vibration sensor 200 relative to the acoustic transducer 220 in the three target frequency bands is greater than the sensitivity of the acoustic transducer 220. It should be noted that in some embodiments, multiple sets of diaphragms and mass blocks can have the same resonant frequency to greatly improve the sensitivity in the target frequency band. For example, when the vibration sensor 200 is used to mainly detect mechanical vibrations in the range of 5kHz to 5.5kHz, the resonant frequencies of multiple sets of diaphragms and mass blocks can be configured to values ​​within this detection range (e.g., 5.3kHz), so that the vibration sensor 200 has higher sensitivity within the detection range compared to the case of only one set of diaphragms and mass blocks. It should be noted that... Figure 2 The number of groups of diaphragms and mass blocks shown is for illustrative purposes only and does not limit the scope of the invention. For example, the number of groups of diaphragms and mass blocks can be one, two, four, etc.

[0059] In some embodiments, when the vibrating assembly 230 has multiple diaphragms, the diaphragm furthest from the acoustic transducer 220 is configured to prevent air from passing through. Figure 2 As shown, the third diaphragm 2313 can be configured to prevent air from passing through. This configuration creates a sealed space between the third diaphragm 2313 and the acoustic transducer 220, allowing for better vibration feedback. It should be noted that in some embodiments, the diaphragm furthest from the acoustic transducer 220 can be configured to allow air to pass through. For example, when a conductive housing is provided outside the pickup hole 211, the conductive housing and the acoustic transducer 220 form a containment space, where the air can effectively reflect vibration information.

[0060] Figure 3This is a schematic diagram of the vibration sensor structure according to some embodiments of this specification.

[0061] like Figure 3 As shown, in some embodiments, the vibration component 330 in the vibration sensor 300 may include a set of diaphragms 331 and a mass block 332, which are connected to the sound sensor 320 via a support structure 333. Specifically, the mass block 332 is physically connected to the diaphragm 331, and the mass block 332 is positioned on the outer side of the diaphragm 331. In some embodiments, the mass block 332 resonates in response to vibrations in the external environment. The resonance generated by the diaphragm 331 and the mass block 332 transmits the external vibration signal to the acoustic transducer 320, thereby enhancing the sensitivity of the vibration component 330 near the resonant frequency, realizing the process of converting the vibration signal into an electrical signal after amplification within the target frequency band.

[0062] In some embodiments, since the vibration sensor 300 includes only one set of diaphragms 331 and mass blocks 332, in order to enable it to have better sound pickup, in some embodiments the diaphragms 331 may be airtight.

[0063] In some embodiments, the resonant frequency of each diaphragm and mass block is related to parameters of the diaphragm and / or mass block, including the modulus of the diaphragm, the volume of the cavity formed between the acoustic transducer and the diaphragm, the radius of the mass block, the height of the mass block, the density of the mass block, and combinations thereof. Specifically, the mathematical relationship between the resonant frequency and the parameters can be found in Equation 1 of the specification.

[0064] Please continue to refer to this. Figure 2 In this embodiment, the vibration assembly 230 may include a first diaphragm 2311, a second diaphragm 2312, and a third diaphragm 2313 arranged sequentially in the vibration direction; the mass block may include a first mass block 2321, a second mass block 2322, and a third mass block 2323 arranged sequentially in the vibration direction. The first diaphragm 2311 is connected to the first mass block 2321, the second diaphragm 2312 is connected to the second mass block 2322, and the third diaphragm 2313 is connected to the third mass block 2323. In some embodiments, the distance between any two adjacent diaphragms among the first diaphragm 2311, the second diaphragm 2312, and the third diaphragm 2313 is not less than the maximum amplitude of the two adjacent diaphragms. This arrangement is used to ensure that the diaphragms do not interfere with adjacent diaphragms during vibration, thereby affecting the transmission effect of the vibration signal. In some embodiments, when the vibration assembly 230 includes multiple sets of diaphragms and mass blocks, the diaphragms are arranged sequentially along the vibration direction perpendicular to the diaphragm. In some embodiments, the distance between adjacent diaphragms may be the same or different. In some embodiments, the diaphragm may form multiple cavities in the gap between it and its adjacent diaphragms, and the multiple cavities between the diaphragm and its adjacent diaphragms may contain air and allow the diaphragm to vibrate therein.

[0065] In some embodiments, the vibration assembly 230 can further include a limiting structure (not shown in the figure) configured to make the distance between adjacent diaphragms in the vibration assembly no less than the maximum amplitude of the adjacent diaphragms. In some embodiments, the limiting structure can be connected with the edge of the diaphragm and will not interfere with the vibration of the diaphragm by controlling the damping of the limiting structure.

[0066] In some embodiments, the mass in the vibration assembly 230 can include multiple, and the multiple masses can be respectively arranged on both sides of the diaphragm. For example, assuming that a vibration assembly includes two masses, the two masses are symmetrically arranged on both sides of the diaphragm. In some embodiments, the mass in the vibration assembly 230 can be located on the same side of the diaphragm, wherein the mass can be arranged on the outer side or the inner side of the diaphragm, wherein the side of the diaphragm close to the acoustic transducer 220 is the inner side, and the side of the diaphragm away from the acoustic transducer 220 is the outer side. It should be noted that in some embodiments, the mass in the vibration assembly can be located on different sides of the diaphragm, such as the first mass 1321 and the second mass 2322 located on the outer side of the corresponding diaphragm, and the third mass 2323 located on the inner side of the corresponding diaphragm.

[0067] In some embodiments, the diaphragm is configured as a thin film structure capable of passing air, and in some embodiments, the diaphragm can be a gas permeable membrane. The diaphragm is configured to pass air while the vibration signal enables the vibration assembly 230 to generate vibrations, so as to be further penetrated through the gas permeable membrane and received by the acoustic transducer, thereby improving the sensitivity at the target frequency band. In some embodiments, the material of the diaphragm is a material capable of producing elastic deformation within a certain range. Specifically, the diaphragm can be made of at least one of the following materials: PTFE (polytetrafluoroethylene), ePTFE (expanded polytetrafluoroethylene), PES (polyether sulfone), PVDF (polyvinylidene fluoride), PP (polypropylene), PETE (polyethylene terephthalate), nylon, NC (nitrocellulose), and MCE (mixed cellulose), etc. In some embodiments, the diaphragm and the mass can be connected by clamping, bonding or one-piece forming, etc., and the connection manner is not limited in the present specification. In some embodiments, the thickness of the diaphragm can be 0.05 μm to 100 μm. Specifically, the thickness of the diaphragm is related to the material of the diaphragm, for example, when ePTFE (expanded polytetrafluoroethylene) is selected as the diaphragm material, the thickness is 0.5 μm to 100 μm, and preferably the ePTFE film thickness is 1 μm to 10 μm, such as 2 μm, 5 μm, 7 μm, etc. In some embodiments, preferably, the minimum air permeability of the ePTFE film can be controlled to be not less than 10 L / hr to ensure good air permeability, and the ePTFE film provides a certain degree of waterproof performance to protect the internal components. In some embodiments, other gas permeable materials with a modulus of 1 GPa to 10 GPa or one-tenth to one-hundredth of the modulus of the sensitive element 222 in the acoustic transducer 220 can also be selected as the diaphragm, and the sensitive element is a device in the acoustic transducer 220 for receiving the vibration signal. In some embodiments, the materials and sizes of the plurality of diaphragms in the vibration assembly 230 can be different or the same. For example, the first diaphragm 2311 can be made of nylon, and the second diaphragm 2312 can be made of ePTFE material; the radius of the third diaphragm 2313 can be larger than that of the first diaphragm 2311 and the second diaphragm 2312.

[0068] In some embodiments, when the diaphragm is configured to be gas impermeable, the material of the diaphragm can be a high molecular film such as polyurethane, epoxy resin, acrylate, etc., or a metal film such as copper, aluminum, tin or other alloy and its composite film, etc. In some embodiments, the above-mentioned gas permeable membrane can also be treated (such as covering the gas permeable holes).

[0069] In some embodiments, the diaphragm can be a thin film material with through-holes, and the diameter of the through-holes is 0.01 μm to 10 μm. Preferably, the diameter of the through-holes can be 0.1 μm to 5 μm, such as 0.2 μm, 0.5 μm, 0.8 μm, 1 μm, 2 μm, etc. In some embodiments, the diameters of the through-holes on the plurality of diaphragms in the vibration assembly 230 can be the same or different, and the diameters of the through-holes on a single diaphragm can be the same or different. In some embodiments, the diameter of the through-holes can also be greater than 5 μm. When the diameter of the through-holes is greater than 5 μm, other materials (such as silica gel, etc.) can be provided on the diaphragm to cover part of the through-holes or part of the area of the through-holes without affecting the air permeability.

[0070] In some embodiments, the material of the mass can be one or more of copper, tin or other alloys and their composite materials. In some embodiments, the vibration sensor 200 can be applied to a MEMS device design, and in the MEMS device process, the diaphragm can be a single layer of material along its thickness direction, such as Si, SiO2, SiNx, SiC, etc., or a double layer or multi-layer composite material, such as Si / SiO2, SiO2 / Si, Si / SiNx, SiNx / Si / SiO2, etc. The counterweight can be a single layer of material, such as Si, Cu, etc., or a double layer or multi-layer composite material, such as Si / SiO2, SiO2 / Si, Si / SiNx, SiNx / Si / SiO2, etc.

[0071] In some embodiments, the vibration assembly 230 can further include a support structure 233 for supporting one or more groups of diaphragms and masses. The support structure 233 is physically connected to the acoustic transducer 220 (e.g., the housing structure 210), and one or more groups of diaphragms and masses are connected to the support structure 233. Specifically, the support structure 233 is physically connected to the housing structure 210, and the physical connection can include clamping, bonding or one-piece forming, etc. In some embodiments, the support structure 233 is preferably bonded to the housing structure 210, and the bonding material can include but is not limited to epoxy and silicone, etc.

[0072] In some embodiments, the support structure can also be connected to the support structure 233 to achieve fixed support to control the spacing between adjacent diaphragms and to ensure the transmission effect of the vibration signal.

[0073] Figure 4 is a structural schematic diagram of a vibration assembly according to some embodiments of the present specification.

[0074] Reference is made to Figure 2 and Figure 4In some embodiments, one or more sets of diaphragms and masses in the vibration assembly are located within the space enclosed by the support structure 233 and are physically connected to the support structure 233. Specifically, the physical connection can be by adhesion, clamping, or the like. Preferably, the connection can be by adhesion, and the adhesive material can include, but is not limited to, epoxy and silicone, and the like. In some embodiments, the support structure 233 can have a tubular structure with hollow and openings at both ends, and the cross section of the tubular structure can be rectangular, triangular, circular, or other shapes. In some embodiments, the cross-sectional area of the tubular structure can be the same everywhere, or can not be completely the same, such as having a larger cross-sectional area near one end of the acoustic transducer 220. In some embodiments, one set of diaphragms and masses in the vibration assembly 230 can be mounted at the openings of the support structure 233.

[0075] In some embodiments, the diaphragms can be embedded on the inner wall of the support structure 233 or embedded in the support structure 233. In some embodiments, the diaphragms can vibrate within the space inside the support structure 233 while the diaphragms can completely block the openings of the support structure, i.e., the area of the diaphragms can be greater than or equal to the opening area of the support structure. Such a configuration allows the air vibrations (e.g., sound waves) in the external environment to pass through the diaphragms as much as possible and then be picked up by the pickup device 221, which can effectively improve the pickup quality.

[0076] In some embodiments, the support structure 233 is made of a gas-impermeable material. The gas-impermeable support structure 233 can cause the air vibration signal to cause a change in the sound pressure (or air vibration) in the support structure 233 during transmission, so that the vibration signal inside the support structure 233 is transmitted to the acoustic transducer 220 through the pickup hole 211, and during transmission, it will not escape outward through the support structure 233, thereby ensuring the sound pressure intensity and improving the sound transmission effect. In some embodiments, the support structure 233 can include one or more of metal, alloy material (such as aluminum alloy, chromium-molybdenum steel, scandium alloy, magnesium alloy, titanium alloy, magnesium-lithium alloy, nickel alloy, etc.), hard plastic, foam, and the like.

[0077] Reference Figure 4 In some embodiments, in the vibration direction of the diaphragm, the projection area of the mass is located within the projection area of the diaphragm, i.e., in the direction parallel to the surface connecting the diaphragm and the mass (i.e., perpendicular to the vibration direction), the cross-sectional area of the mass is smaller than the cross-sectional area of the diaphragm. In combination with Figure 2 For example, the first mass 2321 is located within the projection area of the first diaphragm 2311; the second mass 2322 is located within the projection area of the second diaphragm 2312, and the third mass 2323 is located within the projection area of the third diaphragm 2313. By ensuring that the cross-sectional size of the mass is smaller than that of the diaphragm, the mass will not interfere with the vibration of the diaphragm.

[0078] In some embodiments, the projected area of the mass in the direction perpendicular to the surface connected to the diaphragm and the mass (i.e. perpendicular to the direction of vibration) does not overlap with the projected area of the support structure. Such a configuration is to avoid the vibration of the diaphragm and the mass being limited by the support structure 233.

[0079] In some embodiments, the shape of the diaphragm can include a circle, a rectangle, a triangle, or an irregular shape, etc. In some embodiments, the shape of the diaphragm can also be configured according to the shape of the support structure or the conduit, which is not limited in the present specification. In some embodiments, the shape of the mass can be a cylinder, a circular truncated cone, a circular cone, a cube, a triangular body, etc. The size and material of the mass will be described later, and the shape of the mass is not limited in the present specification.

[0080] In some embodiments, when the mass or the diaphragm has a circular outer contour, the mass can be concentrically arranged with the diaphragm. When the concentrically arranged mass vibrates, the kinetic energy is more evenly dispersed on the diaphragm, so that the diaphragm can better respond to the vibration. In some other embodiments, the mass can also be arranged at other positions of the diaphragm, such as an eccentric position. The eccentric position refers to that the mass is not concentrically arranged with the diaphragm. Preferably, the eccentric distance between the mass and the diaphragm can be less than 50 μm. In some embodiments, the resonance frequency of the one or more groups of diaphragms and masses is less than the resonance frequency of the acoustic transducer so that the sensitivity of the vibration sensor in one or more target frequency bands is greater than the sensitivity of the acoustic transducer. In some embodiments, the relationship between the diaphragm and the mass and the resonance frequency and the sensitivity of the acoustic transducer can be seen from the frequency response curve of the vibration sensor. Figure 5 In some embodiments, the resonance frequency of the one or more groups of diaphragms and masses is less than the resonance frequency of the acoustic transducer so that the sensitivity of the vibration sensor in one or more target frequency bands is greater than the sensitivity of the acoustic transducer. In some embodiments, the relationship between the diaphragm and the mass and the resonance frequency and the sensitivity of the acoustic transducer can be seen from the frequency response curve of the vibration sensor.

[0081] Specifically, in some embodiments, the one or more groups of diaphragms and masses can be configured to have a resonance frequency that is 1 kHz to 10 kHz, such as 2 kHz, 3 kHz, 5 kHz, or 7.5 kHz, etc., lower than the resonance frequency of the acoustic transducer, so that the overall sensitivity of the vibration sensor is improved. In some embodiments, when the acoustic transducer is the aforementioned air conduction microphone, the one or more groups of diaphragms and masses are configured to have a resonance frequency that is 1 kHz to 10 kHz, such as 1.5 kHz, 2 kHz, 3 kHz, or 5 kHz, etc., lower than the resonance frequency of the air conduction microphone, so that the sensitivity of the vibration sensor in one or more target frequency bands is greater than the sensitivity of the acoustic transducer.

[0082] Figure 5 In some embodiments, the resonance frequency of the one or more groups of diaphragms and masses is less than the resonance frequency of the acoustic transducer so that the sensitivity of the vibration sensor in one or more target frequency bands is greater than the sensitivity of the acoustic transducer. In some embodiments, the relationship between the diaphragm and the mass and the resonance frequency and the sensitivity of the acoustic transducer can be seen from the frequency response curve of the vibration sensor.

[0083] In some embodiments, the resonance frequency of the one or more groups of diaphragms and masses is less than the resonance frequency of the acoustic transducer so that the sensitivity of the vibration sensor in one or more target frequency bands is greater than the sensitivity of the acoustic transducer. In some embodiments, the relationship between the diaphragm and the mass and the resonance frequency and the sensitivity of the acoustic transducer can be seen from the frequency response curve of the vibration sensor. Figure 5In some embodiments, the frequency response curve of the vibration sensor under the action of the one or more sets of diaphragms and masses has multiple resonance peaks. In the figure, f1, f2 and f3 correspond to the resonance peaks of the added sets of masses and diaphragms, respectively, and f0 is the resonance peak of the acoustic transducer. In some embodiments, each set of diaphragms and masses in the one or more sets of diaphragms and masses corresponds to one of the one or more different target frequency bands, so that the sensitivity of the vibration sensor in the corresponding target frequency band is greater than the sensitivity of the acoustic transducer. In the figure, the solid line is the frequency response curve 500 of the vibration sensor after adding the sets of masses and diaphragms. After adding the one or more sets of diaphragms and masses with resonance frequencies less than the acoustic transducer, the vibration sensor corresponds to one or more resonance peaks.

[0084] As can be seen from the figure, the frequency response curve 500 of the vibration sensor has four resonance peaks, and its sensitivity is at least improved by AS relative to the acoustic transducer. At the same time, as can be seen from the frequency response curve of the acoustic transducer (i.e., the curve where the resonance peak f0 is located), the vibration sensor has higher sensitivity in the frequency band of f1-f3. As can be seen, the diaphragms and masses increase the width of the frequency band with higher sensitivity of the vibration sensor, so that it can receive vibration signals in a larger frequency range, increasing the receiving frequency range and sensitivity of the vibration sensor. Compared with the way of increasing the receiving frequency range by adding multiple acoustic transducers with different resonance peaks, the overall volume of the device is reduced, the cost is reduced, and the performance is stronger on the basis of higher integration.

[0085] For example, in some embodiments, the resonance frequencies of the one or more sets of diaphragms and masses are different from each other. Figure 4 Taking three sets of diaphragms and masses as an example, the resonance frequencies of the three sets of diaphragms f1, f2 and f3 can be 1.5 kHz, 2 kHz and 2.5 kHz, respectively. In some embodiments, by this setting, the vibration sensor can obtain better pickup capability, especially better voice information in the corresponding frequency band.

[0086] In some embodiments, the resonance frequencies of the one or more sets of diaphragms and masses are related to parameters of the diaphragms and / or masses, including at least one of the modulus of the diaphragm, the volume of the cavity formed between the acoustic transducer and the diaphragm, the radius of the mass, the height of the mass, and the density of the mass. In some embodiments, the relationship between the resonance frequencies of the multiple sets of diaphragms and masses and the sensitivity can be expressed as:

[0087] (S, f) = g (K film ,K foam ,V cavity ,R m ,h m ,ρ m ) (1)

[0088] where S is the sensitivity of the vibration sensor after setting the vibration assembly, f is the resonance frequency of the vibration assembly, K film is the stiffness of the diaphragm, K foam is the stiffness of the support structure, V cavity is the volume of the cavity, R m is the radius of the mass, h m is the height of the mass, r m is the density of the mass. The volume of the cavity V cavity is the volume of the space formed between the sensitive element 222 on the pickup device 221 and the diaphragm in the vibration assembly 230 closest to it, such as the first diaphragm 2311 in the vibration sensor 200. Figure 2

[0089] Specifically, in some embodiments, the sensitivity S decreases with the increase of the stiffness of the diaphragm K film , decreases with the increase of the stiffness of the support structure K foam , increases first and then decreases with the increase of the volume of the cavity V cavity , increases first and then decreases with the increase of the radius of the mass R m , increases with the increase of the height of the mass h m , and increases with the increase of the density of the mass r m . The resonance frequency f of the vibration assembly increases with the increase of the stiffness of the diaphragm K film , increases with the increase of the stiffness of the support structure K foam , decreases first and then increases with the increase of the radius of the mass R m , decreases with the increase of the height of the mass h m , and decreases with the increase of the density of the mass r m . In some embodiments, the size of the sensitivity and the resonance frequency can be adjusted by controlling the stiffness of the diaphragm, the volume of the cavity, and the material and size of the mass.

[0090] Figure 6 is a schematic diagram of a vibration sensor structure according to some embodiments shown in this specification.

[0091] In some embodiments, one or more groups of diaphragms and masses in the vibration sensor 600 can be arranged in the pickup hole parallel to the radial cross section of the pickup hole (i.e. perpendicular to the vibration direction). As Figure 6 shown, in some embodiments, a conduit 611 can be arranged at the pickup hole, and the diaphragms and masses include a first diaphragm 6311, a second diaphragm 6312, a first mass 6321, and a second mass 6322 arranged in the pickup hole parallel to the radial cross section of the pickup hole. In some embodiments, the conduit 611 can be made of a gas-impermeable material, which functions similarly to the support structure 233 in the vibration sensor 200 described above. When calculating the sensitivity and the resonance frequency of the vibration assembly, the stiffness of the support structure K​foam The stiffness of the conduit 611 can be taken from the material of the conduit 611. In some embodiments, in order to ensure the free vibration of the mass, the mass is not in contact with the inner wall of the sound hole or the conduit 611. It should be noted that the provision of the conduit 611 is only a specific embodiment and does not limit the scope of the present application. For example, in some embodiments, the conduit 611 can also not be provided, and one or more sets of diaphragms and masses are directly connected to the sound hole, or a support structure is provided in the sound hole and supports one or more sets of diaphragms and masses.

[0092] In some embodiments, the first mass 6321 and the second mass 6322 can simultaneously generate resonance in response to the vibration of the external environment, and the resonance generated by the first diaphragm 6311, the second diaphragm 6312, the first mass 6321 and the second mass 6322 transmits the vibration signal of the external environment to the acoustic sensor 620 through the conduit 611 and converts it into an electrical signal, thereby realizing the process of strengthening the vibration signal in one or more target frequency bands and converting it into an electrical signal. It should be noted that, Figure 6 The number of sets of diaphragms and masses shown in FIG. 6 is two, which is only for illustration and does not limit the protection scope of the present application. For example, the number of sets of diaphragms and masses can be one, three or other.

[0093] In some embodiments of the present application, a sound input device is also provided, which includes the vibration sensor in the foregoing embodiments, and the sound is picked up by the vibration sensor and converted into an electrical signal for further processing.

[0094] The above has described the basic concept, and it is obvious that the above-mentioned disclosure of the application is only as an example and does not limit the present application. Although it is not explicitly stated here, those skilled in the art can make various modifications, improvements and corrections to the present application. Such modifications, improvements and corrections are suggested in the present application, so such modifications, improvements and corrections still belong to the spirit and scope of the exemplary embodiments of the present application.

[0095] Meanwhile, specific terms are used in the present application to describe the embodiments of the present application. As "one embodiment", "an embodiment" and / or "some embodiments" mean a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that the "one embodiment" or "one embodiment" or "one alternative embodiment" mentioned in different places in the present application does not necessarily refer to the same embodiment. In addition, some features, structures or characteristics in one or more embodiments of the present application can be properly combined.

[0096] Moreover, those skilled in the art will appreciate that the various aspects of the disclosure can be illustrated and described by means of a number of illustrative examples, including any new and useful devices, methods, products, or materials, or any new and useful improvements to the same, including any products or processes presently known or later developed in the art. Accordingly, the various aspects of the disclosure can be embodied in hardware and / or in software (including firmware, resident software, micro-code, etc.) that runs on hardware, and that works alone or in combination with other software. Either of these hardware or software embodiments can be referred to as a "data block," "module," "engine," "unit," "component," or "system." Moreover, the various aspects of the disclosure can be embodied as a computer program product that includes computer-readable program code.

[0097] Moreover, the order of execution or performance of the operations of the aspects of the disclosure illustrated and described herein is not essential, unless otherwise specified. Accordingly, some of the operations can be performed in a different order or concurrently with one another. Furthermore, where indicated, aspects of the disclosure can be implemented via an apparatus comprising a processor configured to perform the recited operations, and / or a computer program comprising program code configured to make a processor perform the recited operations.

[0098] Similarly, it is to be noticed that the term "comprising" is to be construed as specifying the presence of stated features or steps and is not to be construed as limiting them. It is also to be noticed that for the sake of clarity, the attached drawings can not necessarily be to scale and that relative dimensions of different elements in these figures can be exaggerated or reduced.

[0099] Some embodiments use numerical values to describe components, quantities of attributes. It is to be understood that such numerical values used in the description of the embodiments are, in some examples, modified by the use of the terms "about," "approximately," or "substantially," etc. Unless otherwise stated, "about," "approximately," or "substantially" mean that the value is ±20% of the stated value. Accordingly, numerical values used in the description and claims of some embodiments are approximations that can vary depending on the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical values are those obtained using the specified instrumentation and methodology. Although the numerical ranges and values given above are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, can contain certain errors associated with testing measurements.

[0100] Finally, it should be understood that the embodiments described herein are only given by way of example. Other variations might fall within the scope of the present description. Accordingly, the present description is not limited to the embodiments described herein. Instead, other alternative configurations can be used and still fall within the scope of the present description. For example, the present description can be used in other applications and with other configurations, and are not limited to the specific configurations described herein.

Claims

1. A vibration sensor, comprising: an acoustic transducer; the acoustic transducer comprising a housing and a pickup device; a vibration assembly connected with the acoustic transducer, the vibration assembly being configured to transfer an external vibration signal to the acoustic transducer to generate an electrical signal, the vibration assembly comprising one or more sets of diaphragms and masses, the masses being physically connected with the diaphragms, wherein a frequency response curve of the vibration sensor under the action of the one or more sets of diaphragms and masses has a plurality of resonance peaks; when the vibration assembly comprises the one set of diaphragms and masses, the vibration sensor is configured to have a sensitivity greater than that of the acoustic transducer within a target frequency band; when the vibration assembly comprises the multiple sets of diaphragms and masses, the vibration sensor is configured to have a sensitivity greater than that of the acoustic transducer within one or more target frequency bands.

2. The vibratory sensor of claim 1, wherein, the multiple sets of diaphragms and masses are arranged in sequence along a vibration direction of the diaphragms; a distance between adjacent diaphragms in the vibration assembly is not less than a maximum amplitude of the adjacent diaphragms.

3. The vibratory sensor of claim 1, wherein, each set of diaphragms and masses in the one or more sets of diaphragms and masses corresponds to one target frequency band in the one or more different target frequency bands, so that the vibration sensor has a sensitivity greater than that of the acoustic transducer within the corresponding target frequency band.

4. The vibratory sensor of claim 3, wherein, a resonance frequency of the one or more sets of diaphragms and masses is less than a resonance frequency of the acoustic transducer so that the vibration sensor has a sensitivity greater than that of the acoustic transducer within the one or more target frequency bands.

5. The vibratory sensor of claim 4, wherein, a difference between the resonance frequency of the one or more sets of diaphragms and masses and the resonance frequency of the acoustic transducer is within 1 kHz-10 kHz.

6. The vibratory sensor of claim 3, wherein, resonance frequencies of at least two sets of diaphragms and masses in the multiple sets of diaphragms and masses are different.

7. The vibratory sensor of claim 6, wherein, a difference between two adjacent resonance frequencies in the resonance frequencies of the multiple sets of diaphragms and masses is less than 2 kHz.

8. The vibratory sensor of claim 6, wherein, a difference between two adjacent resonance frequencies in the resonance frequencies of the multiple sets of diaphragms and masses is not greater than 1 kHz.

9. The vibratory sensor of claim 3, wherein, the resonance frequency of the one or more sets of diaphragms and masses is within 1 kHz-10 kHz.

10. The vibratory sensor of claim 3, wherein, the resonance frequency of the one or more sets of diaphragms and masses is within 1 kHz-5 kHz.

11. The vibratory sensor of claim 3, wherein, the resonance frequency of the one or more sets of diaphragms and masses is related to a parameter of the diaphragm and / or the mass, the parameter comprising at least one of a modulus of the diaphragm, a volume of a cavity formed between the acoustic transducer and the diaphragm, a radius of the mass, a height of the mass, and a density of the mass.

12. The vibratory sensor of claim 11, wherein, the modulus of the diaphragm is within 1 GPa-10 GPa.

13. The vibratory sensor of claim 11, wherein, the radius of the mass is within 500 μm-3 mm.

14. The vibratory sensor of claim 1, wherein, and a projection area of the mass is located within a projection area of the diaphragm in the vibration direction of the diaphragm.

15. The vibratory sensor of claim 1, wherein, the vibration assembly further comprises a support structure for supporting the one or more sets of diaphragms and masses, the support structure being physically connected with the acoustic transducer, and the one or more sets of diaphragms and masses being connected with the support structure.

16. The vibratory sensor of claim 15, wherein, The support structure is made of a gas-impermeable material.

17. The vibration sensor of claim 15, wherein, In a direction perpendicular to the surface connected with the diaphragm and the mass, a projected area of the mass does not overlap with a projected area of the support structure.

18. The vibration sensor of claim 1, wherein, The mass is concentrically arranged with the diaphragm.

19. The vibratory sensor of claim 1, wherein, The diaphragm is configured to be capable of passing air.

20. The vibratory sensor of claim 19, wherein, A through hole is arranged on the diaphragm.

21. The vibratory sensor of claim 19, wherein, The diaphragm comprises a gas-permeable film.

22. The vibratory sensor of claim 21, wherein, The diaphragm comprises at least one of polytetrafluoroethylene, expanded polytetrafluoroethylene, polyethersulfone, polyvinylidene fluoride, polypropylene, polyethylene terephthalate, nylon, nitrocellulose, or mixed cellulose.

23. The vibratory sensor of claim 19, wherein, Among the plurality of diaphragms, the diaphragm farthest from the acoustic transducer is configured to be incapable of passing air.

24. The vibration sensor of claim 2, the vibration assembly further comprising a limiting structure configured to make a distance between adjacent diaphragms in the vibration assembly no less than a maximum amplitude of the adjacent diaphragms.

25. The vibratory sensor of claim 1, wherein, The acoustic transducer is a gas-routed microphone. A resonance frequency of the one or more target frequency bands is configured to be lower than a resonance frequency of the gas-routed microphone, 1 kHz~10 kHz.

26. The vibratory sensor of claim 25, wherein, The gas-routed microphone comprises A sound pickup hole, the one or more groups of diaphragms and masses are arranged in the sound pickup hole parallel to a radial cross section of the sound pickup hole; or, Arranged outside the sound pickup hole.

27. The vibratory sensor of claim 26, wherein, The mass does not contact an inner wall of the sound pickup hole.

28. A sound input device comprising the vibration sensor of any one of claims 1~27.

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