Vibration sensor and frequency detection system

Abstract

To provide a vibration sensor and vibration frequency detection system that can be miniaturized and thinned. [Solution] A vibration sensor for detecting vibration frequency, comprising a deformable portion, a gas layer, a metal layer, and a support portion, wherein the gas layer is disposed between the deformable portion and the metal layer, the deformable portion has a resistance layer and a dielectric layer, the deformable portion is configured in a sheet shape, and the deformable portion is configured such that the distance between at least a part of the deformable portion and the metal layer changes when the deformable portion bends due to vibration applied to the vibration sensor, the support portion supports the deformable portion such that the gas layer is formed between the deformable portion and the metal layer, and the vibration sensor is configured to change the reflection loss of radio waves by changing the distance due to the vibration.

Description

Technical Field

[0001] The present invention relates to a vibration sensor and a vibration frequency detection system.

Background Art

[0002] Patent Document 1 discloses a vibration sensor used for diagnosing deterioration of structures such as buildings. The vibration sensor described in Patent Document 1 includes an antenna provided on a housing, a wireless circuit board used to generate and output a signal related to the vibration detected by the vibration sensor, a battery for driving various circuits, and the like.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] ]> A vibration sensor using a battery (power source) or the like requires various components such as a battery, a circuit board, and an antenna, and is likely to be enlarged.

[0005] An object of the present invention is to provide a vibration sensor and a vibration frequency detection system that can be miniaturized and thinned.

Means for Solving the Problems

[0006] According to the present invention, a vibration sensor for detecting frequency is provided, comprising a deformable portion, a gas layer, a metal layer, and a support portion, wherein the gas layer is disposed between the deformable portion and the metal layer, the deformable portion has a resistive layer and a dielectric layer, the deformable portion is configured in a sheet shape, and the deformable portion is configured such that the distance between at least a part of the deformable portion and the metal layer changes as the deformable portion bends due to vibration applied to the vibration sensor, the support portion supports the deformable portion so that the gas layer is formed between the deformable portion and the metal layer, and the vibration sensor is configured such that the reflection loss of radio waves changes as the distance changes due to the vibration, the reflection loss is based on a first power of a first radio wave incident on the deformable portion and a second power of a second radio wave that is reflected by the metal layer after being incident on the deformable portion and radiated from the deformable portion.

[0007] According to the present invention, the vibration sensor is configured such that the vibration causes the deformable part to bend, which changes the distance between at least a part of the deformable part and the metal layer, thereby changing the reflection loss of radio waves. Since the reflection loss of radio waves is used for frequency detection, for example, a wireless circuit board, a power supply circuit and power supply (battery) to drive it are unnecessary, and miniaturization and thinning are possible. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram showing the general configuration of the frequency detection system 100. [Figure 2] Figure 2A is a perspective view of the vibration sensor 2 (vibration sensor body 2B), and Figure 2B is a perspective view showing the vibration sensor 2 (vibration sensor body 2B) shown in Figure 2A with the deformed part 2a removed. [Figure 3] Figure 3 is a side view of the vibration sensor 2 shown in Figure 2A, and is an explanatory diagram of the incident and reflected radio waves. [Figure 4] Figure 4 is a functional block diagram of the information processing unit 1B. [Figure 5] Figure 5 is a functional block diagram of the control unit 12. [Figure 6] Figure 6 is a graph showing how the reflection loss changes as the distance x between the deformed part 2a and the metal layer 2c changes due to vibration of the vibration sensor 2. Figure 6 shows the results (21 graphs in total) when the distance x is changed in increments of 0.001 cm in the range of 0.99 to 1.01 cm. [Figure 7] Figure 7 is a magnified view of the graph shown in Figure 6, specifically the range from 260 to 280 GHz. In Figure 7, the graphs in the area overlapping with arrow Ar are arranged sequentially in the direction of arrow Ar, starting with the graph at x=0.99 cm, then x=0.1, and finally x=0.01 cm. In other words, when looking at the area where the graphs overlap with arrow Ar, the graph adjacent to the graph at x=0.99 cm in the direction of arrow Ar corresponds to the graph at x=0.991 cm (dashed line), and the graph adjacent to this corresponds to the graph at x=0.992 cm (single dot dashed line). [Modes for carrying out the invention]

[0009] Embodiments of the present invention will be described below with reference to the drawings. The various features shown in the embodiments below can be combined with each other. Furthermore, each feature constitutes an independent invention.

[0010] 1. Description of the Configuration of the Embodiment As shown in Figure 1, in this embodiment, the frequency detection system 100 comprises a transmitting / receiving device 1 and a vibration sensor 2 that can communicate with the transmitting / receiving device 1. In the frequency detection system 100, the vibration sensor 2 has a radio wave absorber structure (in this embodiment, a so-called λ / 4 type radio wave absorber structure) and also has a structure that can be bent and deformed (in this embodiment, a deformable part 2a, described later, bends and deforms). As a result, the absorption frequency band of the vibration sensor 2 as a radio wave absorber changes. The detailed configuration of the vibration sensor 2 according to this embodiment will be described in detail later, but as shown in Figure 2, the vibration sensor 2 comprises a deformable part 2a, a support part 2b, a metal layer 2c, and a gas layer 2d. When the deformable part 2a vibrates (the distance x between the deformable part 2a and the metal layer 2c changes), the radio wave absorption characteristics change. The frequency detection system 100 makes it possible to detect the frequency of the vibration sensor 2 by acquiring the power of the radio waves to be transmitted and the power of the radio waves reflected back by the vibration sensor 2.

[0011] 1-1. Transmitter / Receiver 1 As shown in Figures 1 and 4, the transmitting and receiving device 1 comprises a housing 1A, an information processing unit 1B, and an antenna unit 1C.

[0012] 1-1-1. Enclosure 1A Enclosure 1A is a case that houses the information processing unit 1B. An antenna unit 1C is also provided within enclosure 1A.

[0013] 1-1-2. Information Processing Unit 1B The information processing unit 1B has functions such as generating and processing transmission signals and receiving and processing reception signals. Here, the transmission signal is a signal radiated as a radio wave (first radio wave) via the antenna unit 1C, and this radio wave propagates through space to reach the vibration sensor 2. The reception signal is a signal that is received by the antenna unit 1C after the radio wave (second radio wave) reflected by the vibration sensor 2 propagates through space and is processed by the information processing unit 1B.

[0014] As shown in Figure 4, the information processing unit 1B comprises a communication unit 10, a storage unit 11, a control unit 12, an output unit 13, and an input unit 14. Also, as shown in Figure 5, the control unit 12 comprises a transmission unit 120, a reception unit 121, a frequency acquisition unit 122, and a notification unit 123.

[0015] Each component of the above information processing unit 1B may be realized by software or by hardware. When realized by software, various functions can be realized by a CPU executing a computer program. The program may be stored in a non-temporary computer-readable recording medium, may be provided so as to be downloadable from an external server, or may also be realized by so-called cloud computing that reads a program stored in an external storage unit to realize functions. When realized by hardware, it can be realized by various circuits such as an ASIC, an FPGA, or a DRP. In the embodiment, various kinds of information and concepts including these are handled, and these are represented by the high and low of signal values or quantum bits as a set of binary bits composed of 0 or 1, and communication and calculation can be executed by the above software or hardware modes. Note that the software may be a general-purpose OS or a dedicated OS.

[0016] The communication unit 10 can adopt a wired communication means such as, for example, USB, IEEE1394, Thunderbolt (registered trademark), wired LAN network communication, etc. Note that the communication unit 10 may adopt a configuration connected to a communication network via a wireless communication means such as, for example, wireless LAN network communication, mobile communication such as 3G / LTE / 5G, Bluetooth (registered trademark) communication, etc. Also, the communication unit 10 may have a configuration that combines the above-described wired communication means and wireless communication means.

[0017] The storage unit 11 stores various values such as various programs, constants, variables, and setting values of the information processing unit 1B executed by the control unit 12, for example. Also, the storage unit 11 stores information processed by each functional unit of the information processing unit 1B, for example. As the storage unit 11, a storage device such as a solid state drive (SSD) or a random access memory (RAM) that stores temporarily necessary information (arguments, arrays, etc.) related to the calculation of programs can be adopted. In addition to the storage unit 11, the information processing unit 1B may also use an external storage unit (for example, an external storage medium, cloud, etc.) in combination.

[0018] The control unit 12 is configured to execute processing and control related to the information processing of the information processing unit 1B. The control unit 12 can be configured by, for example, a central processing unit (CPU). In the embodiment, the control unit 12 is an example of a processor capable of executing various programs. The control unit 12 realizes various functions related to the information processing unit 1B by, for example, reading out the programs stored in the storage unit 11. Also, the software information processing in the information processing unit 1B is realized by, for example, various programs stored in the storage unit 11 being processed by the control unit 12 as hardware.

[0019] The output unit 13 is, for example, a display unit of the information processing unit 1B. The output unit 13 may be included in the housing 1A or may be externally attached. The output unit 13 displays a screen of a graphical user interface (GUI) operable by the user. As the output unit 13, in addition to display devices such as a CRT display, a liquid crystal display, an organic EL display, a plasma display, and an electronic paper display, display devices such as a lit light or a projector can also be adopted. Whether or not the information processing unit 1B includes the output unit 13 is optional. For example, the output of the information processing unit 1B may be displayed on a display unit at a location independent of the location where the information processing unit 1B is installed. Also, the output unit 13 may have a device that outputs in voice.

[0020] The input unit 14 is configured to receive, for example, operation inputs made by a user. The input unit 14 may be included in the housing 1A or it may be external. The input unit 14 can be, for example, a touch panel, switch buttons, a mouse, a keyboard, etc. Whether or not the information processing unit 1B includes the input unit 14 is optional. For example, operation inputs to the information processing unit 1B may be received by the information processing unit 1B via the communication unit 10 from an information processing terminal located in a separate location independent of where the information processing unit 1B is installed.

[0021] 1-1-2-1. Transmitter 120 The transmitting unit 120 is configured to transmit a first radio wave to the vibration sensor 2. In other words, the transmitting unit 120 is configured to radiate the first radio wave via the antenna unit 1C by performing processing to generate the first radio wave. The signal generated by the transmitting unit 120 is amplified by an amplifier, for example, by an oscillator (not shown), and radiated from the antenna unit 1C as a carrier wave of the desired power.

[0022] The frequency (GHz) of the signal generated by the transmitting unit 120 (the first radio wave transmitted by the transmitting unit 120) specifically includes, for example, 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, and 1500, and may also include a range between any two of the values ​​exemplified here. For example, the first radio wave transmitted by the transmitting unit 120 is 15 GHz or higher. The higher the frequency, the higher the resolution of the vibration frequency detection system 100, and the smaller and thinner the vibration sensor 2 can be. Note that this frequency may be divided into multiple frequency ranges. For example, if defined using the values ​​listed above, it could be a frequency range of 100 GHz or more and 400 GHz or less, and a frequency range of 800 GHz or more and 1000 GHz or less.

[0023] Furthermore, the information processing unit 1B is housed in the housing 1A. In other words, the transmitting unit 120, the receiving unit 121, and the vibration frequency acquisition unit 122 are provided in housing 1A, which is independent of the vibration sensor 2 (housing 2A). In this embodiment, the case in which the transmitting unit 120 and the receiving unit 121 are housed in the same housing 1A was described as an example, but the invention is not limited to this. The transmitting unit 120 and the receiving unit 121 may be housed in separate housings. In this case, the information processing unit 1B will be arranged separately in two separate housings. Preferably, the receiving unit 121 is housed in the same housing as the frequency acquisition unit 122 and the notification unit 123. Furthermore, it is preferable that the information processing unit in the housing that houses the transmitting unit 120 is configured to communicate with the information processing unit in the housing that houses the receiving unit 121.

[0024] 1-1-2-2. Receiving unit 121 The receiving unit 121 is configured to receive a second radio wave from the vibration sensor 2. The receiving unit 121 receives the second radio wave w2 via the antenna unit 1C. The second radio wave is a reflected wave of the first radio wave w1 that was carried to the vibration sensor 2. Because the vibration sensor 2 functions as a radio wave absorber, the second radio wave w2 is attenuated compared to the first radio wave w1. In other words, the second power P2, which corresponds to the second radio wave w2, is smaller than the first power P1, which corresponds to the first radio wave w1.

[0025] 1-1-2-3.Frequency acquisition unit 122 The frequency acquisition unit 122 acquires the frequency using reflection loss based on the first power of the first radio wave and the second power of the second radio wave. Here, the reflection loss is based on the first power of the first radio wave incident on the vibration sensor 2 (deformable part 2a, described later) and the second power of the second radio wave that is reflected by the metal layer 2c of the vibration sensor 2 (deformable part 2a, described later) after being incident on the vibration sensor 2 (deformable part 2a) and radiated from the deformable part 2a.

[0026] The frequency acquisition unit 122 has the function of acquiring power. For example, if the power of the signal transmitted from the transmitting unit 120 (the first radio wave w1 radiated from the antenna unit 1C) is predetermined, the frequency acquisition unit 122 can acquire this value from the storage unit 11. In addition, the frequency acquisition unit 122 can acquire the power of the signal received by the receiving unit 121 (the second radio wave w2 received by the antenna unit 1C) by, for example, using a power detection circuit (not shown) provided in the information processing unit 1B.

[0027] As the deformable part 2a of the vibration sensor 2 vibrates, in other words, as the distance x between the deformable part 2a and the metal layer 2c changes, the radio wave absorption characteristics change, as shown in Figures 6 and 7. Figure 7 shows the radio wave absorption characteristics when the distance x is changed in increments of 0.001 cm within the range of 0.99 to 1.01 cm, and it can be seen that each absorption characteristic is unique depending on the distance x. Figures 6 and 7 are based on simulation results assuming that the thickness of the dielectric layer 2a1 (described later) is 200 μm, the thickness of the dielectric layer 2a3 is 50 μm, the material of the metal layer 2c (described later) is copper (with various properties such as conductivity being the same as copper), and the planar size of these layers is infinite.

[0028] Furthermore, it should be noted that the absorption characteristics shown in Figures 6 and 7 will vary depending on how the deformation portion 2a deforms. For example, in the embodiment, the deformation of the deformation portion 2a is such that a weight portion 2a4 (see Figures 2A and 3) is placed in the center of the deformation portion 2a, and both ends of the deformation portion 2a are supported by support portions 2b. Therefore, the displacement of the central part of the deformation portion 2a is relatively larger than the displacement of the parts at both ends. In other words, during vibration of the deformation portion 2a, the fluctuation of distance x of the part of the deformation portion 2a closer to the support portion 2b is relatively small (the position of the support portion 2b does not change), but the fluctuation of distance x of the part of the deformation portion 2a further from the support portion 2b (the central part) is relatively large. To put it another way, in the embodiment, the distance between at least a part of the deformation portion 2a and the metal layer 2c changes. On the other hand, the way the deformable part 2a vibrates could also involve a structure in which the entire deformable part 2a moves closer to or away from the metal layer 2c. For example, elastic members (e.g., spring members) could be placed at the corners of the deformable part 2a (the four corners if the deformable part 2a is rectangular). In such a configuration, precise elastic members (spring members) would be required, which could increase manufacturing costs. In this respect, the configuration in which the deformable part 2a is supported by the support part 2b offers advantages in terms of manufacturing costs.

[0029] As explained above, the characteristics shown in Figures 6 and 7 may vary depending on the way the deformed portion 2a vibrates, but the principle is the same. In the case of the vibration method of this embodiment, since the distance x changes depending on the part of the deformed portion 2a, for example, the average value of the distance between the deformed portion 2a and the metal layer 2c can be used for distance x, or the shortest distance (shortest distance) between the deformed portion 2a and the metal layer 2c can be used. Also, please note that the absorption characteristics shown in Figures 6 and 7 will vary depending on the constituent materials of the deformed portion 2a and the metal layer 2c. In other words, the characteristics shown in Figures 6 and 7 are merely examples to illustrate the principle of the embodiment.

[0030] Figure 7 shows only the range of 0.99 to 1.01 (cm) as an example, but it is advisable to prepare a number of graphs (absorption characteristics) depending on the length of the assumed distance x and the required accuracy. The radio wave absorption characteristics are specific to the configuration of the vibration sensor 2 (vibration sensor body 2B) and are predetermined. The memory unit 11 stores information related to the relationship between the graph shown in Figure 7 (relationship between reflection loss and frequency). This information may be in the form of a table, or it may be in the form of a calculation formula that is sequentially calculated by the frequency acquisition unit 122.

[0031] In this embodiment, reflection loss (dB) is used as the absorption characteristic of radio waves. Reflection loss can be defined, for example, as -10Log(P2 / P1). Here, P1 corresponds to the first power, which is the power of the first radio wave w1, and P2 corresponds to the second power, which is the power of the second radio wave.

[0032] The frequency acquisition unit 122 can sequentially calculate the reflection loss at predetermined timings based on the values ​​of P1 and P2. Then, as shown in Figure 7, the distance x between the deformed part 2a and the metal layer 2c can be determined based on the acquired reflection loss. By acquiring multiple reflection losses, the vibration state of the deformed part 2a (temporal variation of distance x) can be determined, and as a result, the vibration (frequency) of the vibration sensor 2 can be detected. In this way, the frequency acquisition unit 122 acquires the vibration (frequency) of the vibration sensor 2 based on the first power P1 of the first radio wave w1 and the second power P2 of the second radio wave w2.

[0033] In this embodiment, the frequency acquisition unit 122 is described as having functions such as calculating reflection loss, but it is not limited to this. The calculation may be performed by an external device other than the transmitting / receiving device 1, and the frequency acquisition unit 122 may acquire the calculation result via the communication unit 10.

[0034] 1-1-2-4. Hochi Department 123 The notification unit 123 has the function of notifying the user of vibration information acquired by the vibration frequency acquisition unit 122 from the vibration sensor 2. If the vibration sensor 2 is, for example, a vibrometer, the notification unit 123 controls the output unit 13 to notify the current vibration frequency of the vibration sensor 2. If the vibration sensor 2 is, for example, a seismometer, the notification unit 123 can control the output unit 13 to notify the current seismic intensity. If the vibration sensor 2 is, for example, a sensor used to determine the deterioration of a structure, the notification unit 123 can control the output unit 13 to notify the deterioration state of the structure. The applications of the vibration sensor 2 are not limited to these, and it can be applied to other applications as well. Whether or not the vibration frequency detection system 100 includes a notification unit 123 is optional.

[0035] 1-2. Vibration Sensor 2 The vibration sensor 2 shown in Figures 1 to 3 is configured such that when vibration is applied to the vibration sensor 2, the deformable part 2a bends and deforms (elastically deforms), changing the distance x between the deformable part 2a and the metal layer 2c, thereby changing the reflection loss of radio waves in the vibration sensor 2. In other words, the vibration sensor 2 functions as a radio wave absorber, and is configured to change the reflection loss of radio waves when the vibration sensor 2 vibrates. The vibration sensor 2 is a suitable sensor for the frequency band of 15 GHz or higher (wavelength band of radio waves of 15 GHz or higher) as described in "1-1-2-1. Transmitter 120". Furthermore, the vibration sensor 2 does not require power (power supply, battery), and the applicable radio wave frequency band is high (the applicable radio wave wavelength is short), allowing for miniaturization and thinning. For example, if a vibration sensor 2 for the 300 GHz band is manufactured, it will be 2 cm 3 It is possible to construct it in a size of approximately that.

[0036] Furthermore, at least a portion of the vibration sensor body 2B may be made of a transparent material (a light-transmitting material). If the vibration sensor body 2B is made transparent, for example, at least one of the deformable part 2a and the support part 2b may be made of a transparent material. This improves the design and has advantages, for example, when applying the vibration sensor 2 to a wearable device.

[0037] 1-2-1. Enclosure 2A The housing 2A is a case that houses the vibration sensor body 2B. The housing 2A may also be equipped with an antenna to facilitate the transmission of radio waves to the vibration sensor body 2B.

[0038] 1-2-2. Vibration Sensor Body 2B As shown in Figures 2 and 3, the vibration sensor body 2B is a vibration sensor for detecting vibration frequency and comprises a deformable portion 2a, a support portion 2b, a metal layer 2c, and a gas layer 2d.

[0039] 1-2-2-1. Deformed part 2a The deformable portion 2a has a dielectric layer 2a1 (an example of a first dielectric layer), a resistive layer 2a2, and a dielectric layer 2a3 (an example of a second dielectric layer), and is configured in a sheet shape. The vibration sensor 2 is equipped with a weight portion 2a4, and the deformable portion 2a is provided with the weight portion 2a4. The deformable portion 2a may also have a configuration in which the weight portion 2a4 is placed (for example, inside the dielectric layer 2a1). The deformable portion 2a is constructed by stacking the dielectric layer 2a1, the resistive layer 2a2, and the dielectric layer 2a3 in the order of the dielectric layer 2a1, the resistive layer 2a2, and the dielectric layer 2a3 in the direction from the deformable portion 2a toward the metal layer 2c. The deformable portion 2a is capable of bending deformation, but it is preferable that this deformation is elastic deformation such that the deformable portion 2a returns to its original shape when the vibration stops.

[0040] The width (cm) of the deformed portion 2a when viewed from above is, for example, 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0, 4.2, 4.4, 4.6, 4.8, 5.0, 5.2, 5.4, 5.6, 5.8, 6.0, 6.2, 6.4, 6.6, 6.8, 7.0, 7.2, 7.4, 7.6, 7.8, 8.0, 8.2, 8.4, 8.6, 8.8, 9.0, 9.2, 9.4, 9.6, 9.8, 10.0, and may also be within the range between any two of the examples given here. The width referred to here means the largest width among the deformable parts 2a. For example, if the deformable part 2a is a rectangle, the width corresponds to the length of the longer side.

[0041] <Dielectric layer> The dielectric layers 2a1 and 2a3 sandwich the resistive layer 2a2 to protect it. Various dielectric materials can be used for the dielectric layers 2a1 and 2a3. The dielectric materials constituting dielectric layers 2a1 and 2a3 may include polymer materials. These polymer materials may be synthetic resins (including thermoplastic elastomers) such as polyvinyl chloride, polyvinylidene fluoride, acrylic resin, ethylene vinyl acetate copolymer, polyurethane, acrylic urethane resin, ionomer, polyolefin, polypropylene, polyethylene, silicone resin, polyester, polystyrene, polyimide, polyamide, polysulfone, polyethersulfone, and epoxy resin, or synthetic rubbers such as polyisoprene rubber, polystyrene-butadiene rubber, polybutadiene rubber, chloroprene rubber, acrylonitrile butadiene rubber, butyl rubber, acrylic rubber, ethylene propylene rubber, and silicone rubber. These may be used individually or in combination of two or more to constitute the polymer material. The dielectric layers may also be made of materials such as glass, titanium oxide, alumina, and barium titanate.

[0042] Furthermore, dielectric layers 2a1 and 2a3 may contain flexible materials. Specifically, they may contain flexible materials such as rubber-based materials or elastomers, as described below. In other words, dielectric layers 2a1 and 2a3 can be composed of a material which is a mixture of a dielectric material for imparting dielectric properties and a flexible material for imparting bending properties (elasticity), as described above. Furthermore, if the flexible material also has suitable dielectric properties, it is not necessary to mix in a separate dielectric material. Examples of flexible materials that can be used include natural rubber, isoprene rubber, butadiene rubber, styrene-butadiene rubber, butyl rubber, nitrile rubber, ethylene-propylene rubber, chloroprene rubber, acrylic rubber, chlorosulfonated polyethylene rubber, urethane rubber, silicone rubber, fluororubber, ethylene-vinyl acetate rubber, epichlorohydrin rubber, and polysulfide rubber.

[0043] The constituent materials of dielectric layer 2a1 and dielectric layer 2a3 may be the same or different.

[0044] In addition, while the above describes how flexibility can be imparted by modifying the constituent materials, flexibility can also be imparted by forming a lattice structure or pattern structure in the structure of the deformable part 2a, or by foaming the dielectric layer of the deformable part 2a to make it porous.

[0045] The relative permittivity of dielectric layers 2a1 and 2a3 can be set as appropriate, but specifically, for example, they can be 1.0, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, or 10, and may also be within the range of any two of the values ​​exemplified here. The relative permittivity of dielectric layer 2a1 and dielectric layer 2a3 may be the same or different.

[0046] The thickness (μm) of dielectric layers 2a1 and 2a3 can be, for example, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1500, 2000, 2500, 3000, 4000, 4500, 5000, 6000, 7000, 8000, 9000, 10000, and may be within the range of any two of the values ​​exemplified here. The thicknesses of dielectric layer 2a1 and dielectric layer 2a3 may be the same or different.

[0047] <Resistance layer> The resistive layer 2a2 is positioned and protected between the dielectric layer 2a1 and the dielectric layer 2a3. The constituent material of the resistive layer 2a2 can be, for example, a conductive organic polymer film, a sputtered film, a vapor-deposited film, etc. Furthermore, the constituent materials of the resistive layer 2a2 are preferably composed of carbon materials such as carbon microcoils, carbon nanotubes, and graphene. Here, it is preferable that the resistive layer 2a2 is also easily flexible, similar to the dielectric layers 2a1 and 2a3, so it is preferable to use highly flexible materials such as carbon nanotubes and graphene for the resistive layer 2a2.

[0048] In one embodiment, the resistive layer 2a2 is a so-called solid layer. In other words, the resistive layer 2a2 is composed of a sheet-like structure in which the entire area inside the outer edge of the resistive layer 2a2 is filled with the constituent material of the resistive layer 2a2. Note that the resistive layer 2a2 does not necessarily have to be formed as a solid layer; it may be in a patterned shape, or in a shape in which a part of the solid surface has been removed.

[0049] The thickness (μm) of the resistive layer 2a2 is specifically, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1500, 2000, and may also be within the range of any two of the values ​​exemplified here.

[0050] Furthermore, the resistance value (Ω / sq) of the resistive layer 2a2 is specifically, for example, 20, 30, 40, 50, 50, 60, 70, 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 310, 320, 330, 340, 350, 360, 370, 380, 390, 400, and may also be within the range of any two of the values ​​exemplified here.

[0051] In this embodiment, the dielectric layer has two layers and the resistive layer has one layer, but the invention is not limited to this; the dielectric layer may have three or more layers, or the resistive layer may have two or more layers.

[0052] <Weight section> The weight portion 2a4 functions as a cone and has the function of making it easier to bend (deform) the deformable portion 2a when the vibration sensor 2 vibrates. The weight portion 2a4 also has the function of determining the vibration frequency of the vibration sensor 2 system (the vibration frequency of the deformable portion). The weight portion 2a4 has a density higher than that of the dielectric layers (dielectric layers 2a1 and 2a3) of the deformable portion 2a and is made of a heavy material. The weight portion 2a4 may be made of a metal material, a resin, or a combination of these. The weight portion 2a4 may be attached to the deformation portion 2a separately, or it may be integrally formed with the deformation portion 2a. In this embodiment, the weight portion 2a4 is attached to the dielectric layer 2a1 of the deformation portion 2a separately. The weight portion 2a4 may also be attached to the dielectric layer 2a3. The mounting position of the weight portion 2a4 is preferably in the center of the plane of the deformation portion 2a in order to stably deform the deformation portion 2a, but it is not limited to this. Furthermore, the method of attaching the weight portion 2a4 may be, for example, by adhesive, or by forming an engagement structure and connecting them. If the weight portion 2a4 is integrally formed with the deformation portion 2a, the weight portion 2a4 can be configured to be embedded inside the deformation portion 2a.

[0053] The plan view shape of the weight portion 2a4 may be rectangular (e.g., square, rectangle, etc.) or annular (donut-shaped). If the weight portion 2a4 is annular, the outer and inner edges may be circular or rectangular. When the weight portion 2a4 is annular, the entire deformable portion 2a is more easily deformed uniformly, which can be expected to improve the sensitivity of the sensor.

[0054] The density of the weight portion 2a4 is specifically, for example, 1.5, 2.0, 2.5, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, or 10.0 times the density of the dielectric layers (dielectric layer 2a1 and dielectric layer 2a3), and may be within the range of any two of the values ​​exemplified here. The weight of the weight portion 2a4 is specifically, for example, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 times the weight of the dielectric layer (the total weight of dielectric layer 2a1 and dielectric layer 2a3), and may be within the range of any two of the values ​​exemplified here.

[0055] 1-2-2-2. Support part 2b The support portion 2b is connected to the deformable portion 2a. In this embodiment, the vibration sensor 2 is configured to have a pair of support portions 2b provided to support both ends of the deformable portion 2a. Alternatively, four support portions 2b may be provided to support the four corners of the deformable portion 2a. The support section 2b has a shaft section 2b1, a shaft holding section 2b2, and a frame section 2b3. The shaft section 2b1 is connected to the deformation section 2a, and the shaft holding section 2b2 is fixed to the frame section 2b3 and holds the shaft section 2b1. The shaft section 2b1 is connected to the end of the deformation section 2a.

[0056] The connection between the deformable part 2a and the support part 2b may be, for example, by interlocking grooves (for example, by forming grooves in the support part 2b and inserting the end of the deformable part 2a), by using a claw structure, by using fixing parts such as bolts or screws, by using adhesive, or by combining these methods.

[0057] 1-2-2-3. Metal layer 2c The metal layer 2c functions as a reflective layer that reflects radio waves. In other words, the metal layer 2c is configured to reflect radio waves that have passed through the deformed portion 2a and the gas layer 2d. The metal layer 2c is directly or indirectly connected to the housing 2A and fixed together with the housing 2A. In this embodiment, the metal layer 2c is fixed on the frame portion 2b3 and is therefore indirectly connected to the housing 2A.

[0058] The metal layer 2c preferably has a low resistance value, and for example, a metallic material (such as highly conductive copper or silver) can be used as the metal layer 2c. The metal layer 2c can have a mesh structure (see Figure 2B), or a structure in which the entire area inside the outer edge of the metal layer 2c is formed of metal (a so-called solid structure). When a mesh structure is adopted, an opening is formed, making it easier to ensure a certain degree of transparency, which can be effective depending on the location and application in which the vibration sensor 2 is installed.

[0059] The thickness (μm) of the metal layer 2c can be, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 30, 40, 50, 60, 70, 80, 90, 100, 150, 200, 250, 300, 350, 400, 500, 600, 700, 800, 900, 1000, and may be within the range of any two of the values ​​exemplified here.

[0060] 1-2-2-4. Gas layer 2d A gas layer 2d is placed between the deformable portion and the metal layer. The vibration sensor 2 is able to vibrate because it has a gas layer 2d. In this embodiment, the gas layer 2d is made of air, that is, the gas layer 2d is an air layer, but it may be any other gas besides air.

[0061] The thickness (cm) of the gas layer 2d is specifically, for example, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, and may also be within the range of any two of the values ​​exemplified here.

[0062] 2. Operation Description The transmitting unit 120 of the transceiver 1 transmits the first radio wave w1 to the vibration sensor 2. The transmitting unit 120 may continuously transmit the first radio wave w1, or it may be configured to transmit the first radio wave w1 at predetermined timings or times in order to reduce power consumption. The first radio wave w1 propagates through space and reaches the vibration sensor 2. A portion of the first radio wave w1 as an incident wave is reflected by the resistive layer 2a2, and the remaining portion of the first radio wave w1 as an incident wave (passed wave w3) passes through the dielectric layer 2a1, the resistive layer 2a2, the dielectric layer 2a3, and the gas layer 2d. The passed wave w3 is reflected by the metal layer 2c and becomes the reflected wave w4.

[0063] Here, the phase of the reflected wave w4 changes due to reflection in the metal layer 2c. As a result, the reflected wave w4 interferes with the transmitted wave w3 in the gas layer 2d and is attenuated, and the reflected wave w4 also interferes with the incident wave, the first radio wave w1, and is attenuated. The second radio wave w2, which returns to the transmitting / receiving device 1, is composed of waves reflected by the resistive layer 2a2 and the metal layer 2c. Due to this attenuation, its power is lower than that of the first radio wave w1. In other words, the vibration sensor body 2B functions as a radio wave absorber, absorbing some of the power of the first radio wave w1 by causing interference between the radio waves.

[0064] The receiving unit 121 of the transmitting / receiving device 1 receives the second radio wave w2 via the antenna unit 1C. The frequency acquisition unit 122 then calculates the reflection loss based on the first power P1 of the first radio wave w1 and the second power P2 of the second radio wave w2, and calculates the distance x based on this reflection loss. In one example of this embodiment, the first power P1 of the first radio wave w1 is a predetermined value, so it is possible to use a value stored in the memory unit 11. The second power P2 can be obtained using a power detection circuit (not shown). The reflection loss is given by -10Log(P2 / P1). The distance x can be obtained using a relationship (either a table or an equation) like the one shown in the graph in Figure 7. In other words, since the frequency of the first radio wave w1, etc., is predetermined and known, the distance x can be obtained by using the acquired reflection loss.

[0065] Furthermore, if the vibration frequency detection system 100 includes a notification unit 123, the notification unit 123 notifies the user of the vibration information of the vibration sensor 2 acquired by the vibration frequency acquisition unit 122.

[0066] 3. Description of the operation and effects of the embodiment In the vibration sensor 2 according to this embodiment, the vibration frequency detection system 100 is configured to change the reflection loss of radio waves by changing the distance x between the deformed part 2a and the metal layer 2c, and the vibration frequency is detected based on this reflection loss. As a result, for example, a wireless circuit board, a power supply circuit and power supply (battery) to drive it are unnecessary, and miniaturization and thinning are possible.

[0067] The vibration sensor 2 can be applied to a variety of devices, not only for seismic applications, but also because it can be miniaturized and thinned. For example, the vibration sensor 2 can be applied to wearable devices (such as smartwatches and heart rate monitors) to sense weak vibrations in the body.

[0068] Various embodiments are illustrated below. The embodiments shown below can be combined with each other. [Note 1] A vibration sensor for detecting vibration frequency, It comprises a deformable part, a gas layer, a metal layer, and a support part. The gas layer is disposed between the deformed portion and the metal layer. The deformable portion comprises a resistive layer and a dielectric layer, and the deformable portion is configured in a sheet-like shape, and the deformable portion is configured such that the distance between at least a portion of the deformable portion and the metal layer changes as the deformable portion flexes due to vibrations applied to the vibration sensor. The support portion supports the deformed portion such that the gas layer is formed between the deformed portion and the metal layer. The vibration sensor is configured such that the reflection loss of radio waves changes as the distance changes due to the vibration. A vibration sensor in which the reflection loss is based on a first power of a first radio wave incident on the deformed portion and a second power of a second radio wave that is reflected by the metal layer after being incident on the deformed portion and radiated from the deformed portion. [Note 2] The vibration sensor described in Appendix 1, It also has a weight section, A vibration sensor in which the weight portion is attached to the deformation portion separately from the deformation portion, or is integrally configured with the deformation portion. [Note 3] A vibration sensor as described in Appendix 1 or Appendix 2, The dielectric layer of the deformed portion has a first dielectric layer and a second dielectric layer. The vibration sensor is configured such that the deformable portion is stacked in the order of the first dielectric layer, the resistive layer, and the second dielectric layer in the direction from the deformable portion toward the metal layer. [Note 4] A vibration sensor described in any one of the appendices 1 to 3, The vibration sensor wherein the metal layer has a mesh structure, or a structure in which the entire region inside the outer edge of the metal layer is formed of metal. [Note 5] A frequency detection system having a vibration sensor described in any one of the appendices 1 to 4, It comprises a transmitting unit, a receiving unit, and a frequency acquisition unit. The transmitting unit is configured to transmit the first radio wave to the vibration sensor, The receiving unit is configured to receive the second radio wave from the vibration sensor, The frequency acquisition unit is a frequency detection system that acquires the frequency using the reflection loss based on the first power of the first radio wave and the second power of the second radio wave. [Note 6] The frequency detection system described in Appendix 5, A frequency detection system in which the transmitting unit, the receiving unit, and the frequency acquisition unit are housed in a housing independent of the vibration sensor. [Note 7] A frequency detection system as described in Appendix 5 or Appendix 6, A frequency detection system in which the first radio wave transmitted by the transmitting unit is 15 GHz or higher. [Explanation of Symbols]

[0069] 1: Transceiver 1A: Enclosure 1B: Information Processing Department 1C: Antenna section 2: Vibration sensor 2A: Enclosure 2B: Vibration sensor body 2a: Deformed part 2a1: Dielectric layer 2a2 :Resistance layer 2a3: Dielectric layer 2a4: Weight section 2b: Support part 2b1:Shaft part 2b2: Shaft holding part 2b3: Frame section 2c: Metal layer 2d: Gas layer 10: Communications Department 11: Storage section 12: Control Unit 13: Output section 14: Input section 100: Frequency detection system 120: Transmitter 121: Receiving unit 122: Frequency acquisition part 123: Hochi Department

Claims

1. A vibration sensor for detecting vibration frequency, It comprises a deformable part, a gas layer, a metal layer, and a support part. The gas layer is disposed between the deformed portion and the metal layer. The deformable portion comprises a resistive layer and a dielectric layer, and the deformable portion is configured in a sheet-like shape, and the deformable portion is configured such that the distance between at least a portion of the deformable portion and the metal layer changes as the deformable portion flexes due to vibrations applied to the vibration sensor. The support portion supports the deformed portion such that the gas layer is formed between the deformed portion and the metal layer. The vibration sensor is configured such that the reflection loss of radio waves changes as the distance changes due to the vibration. The vibration sensor wherein the reflection loss is based on a first power of a first radio wave incident on the deformed portion and a second power of a second radio wave that is reflected by the metal layer after being incident on the deformed portion and radiated from the deformed portion.

2. A vibration sensor according to claim 1, It also has a weight section, A vibration sensor in which the weight portion is attached to the deformation portion separately from the deformation portion, or is integrally configured with the deformation portion.

3. A vibration sensor according to claim 1 or claim 2, The dielectric layer of the deformed portion has a first dielectric layer and a second dielectric layer. The vibration sensor is configured such that the deformable portion is stacked in the order of the first dielectric layer, the resistive layer, and the second dielectric layer in the direction from the deformable portion toward the metal layer.

4. A vibration sensor according to claim 1 or claim 2, The vibration sensor wherein the metal layer has a mesh structure, or a structure in which the entire region inside the outer edge of the metal layer is formed of metal.

5. A frequency detection system having a vibration sensor according to claim 1 or claim 2, It comprises a transmitting unit, a receiving unit, and a frequency acquisition unit. The transmitting unit is configured to transmit the first radio wave to the vibration sensor, The receiving unit is configured to receive the second radio wave from the vibration sensor, The frequency acquisition unit is a frequency detection system that acquires the frequency using the reflection loss based on the first power of the first radio wave and the second power of the second radio wave.

6. A frequency detection system according to claim 5, A frequency detection system in which the transmitting unit, the receiving unit, and the frequency acquisition unit are housed in a housing independent of the vibration sensor.

7. A frequency detection system according to claim 5, A frequency detection system in which the first radio wave transmitted by the transmitting unit is 15 GHz or higher.

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