JP2007150654A - Sensor unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sensor unit arranged in the vicinity of the surface of a sheet-like signal transmission apparatus and transmitting results of various measurements to the signal transmission apparatus. <P>SOLUTION: An electromagnetic field is propagated between first and second conductor parts 111, 121 in the sheet-like signal transmission apparatus, which has a region 141 in the vicinity of the surface thereof wherein the electromagnetic field infiltrates, sensor tags 942 each comprising an interface unit connected with a communication unit allocated with an identification code are arranged apart from the signal transmission apparatus, when some of the sensor tags 942 belong to the region 141 wherein the electromagnetic field infiltrates, the sensor tags 942 are communicable with the signal transmission apparatus, and when some of the sensor tags 942 belong to the region 141 wherein the electromagnetic field infiltrates, the sensor tags 942 transmit the identification code to the signal transmission apparatus so as to detect that the sensor tags 942 belong to the region wherein the electromagnetic field infiltrates. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a sensor device capable of transmitting various measurement results to a signal transmission device by being arranged near the surface of a sheet-shaped signal transmission device.

Conventionally, a sheet shape in which a plurality of communication elements are embedded (a cloth shape, a paper shape, a foil shape, a plate shape, a film shape, a film shape, a mesh shape, etc., having a wide surface and a small thickness). The technology relating to the communication device has been proposed by the inventors of the present application. For example, in the following documents, a communication in which a plurality of communication elements embedded in a sheet-like member (hereinafter referred to as “sheet-like body”) transmits signals by relaying signals without forming individual wirings. A device has been proposed.
Japanese Patent Laid-Open No. 2004-007448

  Here, in the technique disclosed in [Patent Document 1], each communication element is arranged at the apex of a lattice-like, triangular, or honeycomb-like figure on the surface of the sheet-like body. Each communication element communicates only with other communication elements arranged in the vicinity by utilizing the fact that the potential change generated by the communication element is strong in the vicinity and attenuated and propagated in the distance.

  By sequentially transmitting the signals between the communication elements by this local communication, the signals are transmitted to the target communication element. The plurality of communication elements are divided into hierarchies by the management function, and route data is set in each hierarchy, so that signals can be efficiently transmitted to the final target communication element.

  On the other hand, according to the inventors' research, there is an electromagnetic field in a narrow region sandwiched between sheet-like bodies facing each other, and the electromagnetic field is changed by changing the voltage between the two sheet-like bodies. A technology has been developed in which the voltage between the sheet-like bodies is changed by the change, the electromagnetic field is advanced, and communication is performed.

  In order to detect the voltage between two sheet-like bodies, it has been common to directly connect a communication device to both of them or provide a connector on the sheet-like body and connect it to the communication device.

  However, if such a wired connection is not performed as much as possible and an external communication device is brought close to the sheet-like body so that a signal can be transmitted, it is easy for the user to use and maintenance efficiency is improved.

  At this time, if various sensors can be used as an external communication device, the convenience is further enhanced.

  Therefore, there is a strong demand for new technologies to meet such demands.

  The present invention responds to such a demand by changing the electromagnetic field in the narrow area sandwiched between the mesh-like conductor part and the sheet-like conductor part and the leaching area outside the mesh-like conductor part. An object of the present invention is to provide a signal transmission device for transmitting.

  In order to achieve the above object, the following invention is disclosed in accordance with the principle of the present invention.

  A sensor device according to a first aspect of the present invention includes a sheet-like signal transmission device and an interface device, and is configured as follows.

  First, the sheet-like signal transmission device has a region in which an electromagnetic field propagates inside and the electromagnetic field is leached in the vicinity of the surface.

  On the other hand, when the interface device is disposed apart from the signal transmission device and belongs to a region where the electromagnetic field is leached, the interface device can communicate with the signal transmission device via the leached electromagnetic field.

  Further, when the identification information is given to the interface device and belongs to a region where the electromagnetic field is leached, the interface code is transmitted to the region where the electromagnetic field is leached by transmitting the identification code to the signal transmission device. Detect that the device belongs.

  In the sensor device of the present invention, the interface device can be configured to be provided with the identification information by an RF tag.

  Further, in the sensor device of the present invention, an elastic body for separating them is arranged between the signal transmission device and the interface device to detect that the interface device belongs to a region where the electromagnetic field is leached. In this case, it can be configured to detect that pressure is applied in the vicinity of the interface device.

  Further, in the sensor device of the present invention, an elastic body for separating them is arranged between the signal transmission device and the interface device to detect that the interface device belongs to a region where the electromagnetic field is leached. In this case, the deformation amount of the elastic body can be detected based on the strength of communication between the interface device and the signal transmission device.

  In the sensor device of the present invention, the elastic body can be configured to be a rubber, sponge, or metal beam structure.

  In the sensor device of the present invention, a dielectric whose dielectric constant changes due to a change in physical quantity is disposed between the signal transmission device and the interface device, and the interface device is located in a region where the electromagnetic field is leached. Can be configured to detect the change in the physical quantity based on the strength of communication between the interface device and the signal transmission device.

  In the sensor device of the present invention, the interface device may be configured integrally with the dielectric, and the dielectric and the signal transmission device may be configured to be detachable.

  ADVANTAGE OF THE INVENTION According to this invention, the sensor apparatus which can transmit a various measurement result to the said signal transmission apparatus can be provided by arrange | positioning in the surface vicinity of a sheet-like signal transmission apparatus.

  Embodiments of the present invention will be described below. The embodiments described below are for explanation, and do not limit the scope of the present invention. Therefore, those skilled in the art can employ embodiments in which each of these elements or all of the elements are replaced with equivalent ones, and these embodiments are also included in the scope of the present invention.

  In the following, regarding a signal transmission device having a flat plate shape, an interface device (connector) for acquiring a signal in close proximity to the signal transmission device and sending a signal, a sensor constituted by a combination thereof, These will be described in order.

  In the following, in order to facilitate understanding, what is a conductor in the frequency band of the electromagnetic wave used for signal transmission is referred to as “conductor”, and what is a dielectric in the frequency band is referred to as “dielectric”. . Therefore, for example, what is an insulator against a direct current may be referred to as a “conductor”.

(Signal transmission device)
FIG. 1 is an explanatory diagram showing a schematic configuration of the signal transmission device according to the present embodiment. Hereinafter, a description will be given with reference to FIG.

  This figure (b) is sectional drawing of the signal transmission apparatus 101 which concerns on this embodiment. As shown in the figure, the signal transmission device 101 includes a mesh-like first conductor portion 111 and a flat plate-like second conductor portion 121 substantially parallel to the first conductor portion 111.

  Here, a region sandwiched between the first conductor portion 111 and the second conductor portion 121 is a narrow space region 131, and a region on the upper side of the first conductor portion 111 in this drawing is a leaching region 141.

  This figure (a) is a top view of the signal transmission device 101. The first conductor portion 111 of this embodiment has a square mesh shape, and the second conductor portion 121 can be seen through the square.

  Further, the repeating unit of the mesh is equal to the distance between the centers of the squares adjacent to each other, which is substantially equal to the length of one side of the square.

  In this embodiment, the gap region 131 and the leaching region 141 are both air, but either one or both or part of them is made of various dielectrics, water or earth, or vacuum. May be.

  The outer shapes of the first conductor portion 111 and the second conductor portion 121 are all sheet-like (cloth-like, paper-like, foil-like, plate-like, film-like, film-like, mesh-like, etc., and have a wide surface. Is thin.)

  Therefore, for example, when the wall of the room is used as the signal transmission device of the present embodiment, first, a metal foil is pasted as the second conductor portion 121, and then an insulator is sprayed, and then the first conductor portion 111 is a metal. Paste the net, and then paste the insulator wallpaper.

  Now, in this way, in the signal transmission device 101, attention is paid to the electromagnetic wave mode propagating between the narrow regions 131 sandwiched between the first conductor portion 111 and the second conductor portion 121.

  If the first conductor 111 is not a mesh and has a structure without a foil-like opening, the electromagnetic wave is completely confined in the narrow space 131.

  However, the first conductor portion 111 has a mesh-like structure and has an opening. With such a shape, the electromagnetic field oozes to a height that is about the same as the mesh interval. A region where the electromagnetic wave oozes out is a leaching region 141.

  The height (thickness) of the leaching region 141 is approximately the same as the mesh repeating unit. Actually, the intensity of the electromagnetic wave attenuates exponentially according to the distance from the surface of the first conductor portion 111.

  FIG. 2 is an explanatory diagram showing a state of an interface device having the simplest shape with respect to the signal transmission device of the present embodiment. This figure shows a state in which communication is performed with the signal transmission device 101 by using a loop antenna or a dipole antenna as an interface device. Hereinafter, a description will be given with reference to FIG.

  In the drawing, four combinations of the communication circuit 201 that performs transmission and reception and the loop antenna 202 connected to the communication circuit are shown in the leaching region 141 existing on the surface of the mesh-shaped first conductor portion 111. ing.

  The length of the loop type antenna 202 is preferably about half of the wavelength of the electromagnetic wave transmitted by the signal transmission device 101, but communication is possible even if it is larger or smaller than this.

  This figure shows a case where the rectangular loop antenna 202 is arranged in parallel to the surface of the first conductor portion 111 and is arranged perpendicular to the surface of the first conductor portion 111.

  Further, in this figure, a case where both ends of the U-shaped loop antenna 202 are terminated by the communication circuit 201 and arranged in parallel to the surface of the first conductor portion 111 is shown.

  Further, in this figure, the U-shaped loop antenna 202 is connected to the communication circuit 201 and the end thereof extends to the opposite side of the communication circuit 201. The case where it arrange | positions perpendicularly | vertically to the surface of the part 111 is shown.

  In addition, an interface device using a dipole antenna 203 in which the core wire of the coaxial cable is exposed is also illustrated. In this case, electromagnetic waves can be exchanged between the communication device connected to the coaxial cable and the signal transmission device 101 by bringing the core wire of the dipole antenna 203 close to the first conductor portion 111.

  These communication circuits 201 can communicate with each other, or the communication device connected to the coaxial cable and the communication circuit 201 can communicate with each other via the signal transmission device 101. In addition, although not shown in the figure, when there is a communication device that is directly connected to the first conductor portion 111 and the second conductor portion 121 by wire, communication with the communication device is also possible. In this way, any one-to-one, one-to-N, N-to-one, or N-to-N communication is possible.

  Further, an RFID tag circuit can be used as the communication circuit 201, and this apparatus can be used as a tag reading apparatus, and a sensor can be mounted there. In addition, there is a usage form in which a communication circuit is connected to an external device by wiring, or is connected to a coaxial cable instead of being connected to the communication circuit and connected to the external device.

  It is also possible to supply power by charging the interface device side using microwaves.

  In the above-described embodiment, the second conductor 121 is a conductor without a foil-like opening, but the second conductor 121 may be a mesh similar to the first conductor 111. FIG. 3 is a cross-sectional view of such a configuration.

  As shown in this figure, there is a counter area 151 corresponding to the leaching area 141 on the outside of the second conductor portion 121, and electromagnetic waves ooze out here. Therefore, since electromagnetic waves are leached on both the front and back surfaces, signals can be exchanged by bringing the interface device close to either surface.

Now, the theoretical background of the leaching region 141 will be briefly described below. In the signal transmission device 101 configured as described above, the electromagnetic wave that travels without “radiating” the electromagnetic wave to the outside of the signal transmission device 101 in the gap region 131 (and the leaching region 141 and the opposing region 151 in the vicinity thereof). Mode φ _n exists.

  Here, the height L of the near field where the electromagnetic field of the same degree as the gap region 131 oozes out and there is no electromagnetic radiation in the distance is L = d / where the unit length of the mesh repetition is d. It is about (2π).

Here, in the leaching region 141 and the opposing region 151, when the distance from the surface of the first conductor portion 111 or the second conductor portion 121 is z, the amplitude of the ^leaked electromagnetic wave is approximately e ^{−z / L.} Attenuates.

Therefore, the interface device is arranged within a distance L from the first conductor portion 111 (or the second conductor portion 121), and φ _n is induced to transmit a signal. Depending on the sensitivity of the interface device, the distance d may be about d instead of the distance L. That is, the thickness of the leaching region 141 (or the opposing region 151) can be considered to be about L to d.

  The following is considered in more detail. FIG. 4 is an explanatory diagram showing the state of the coordinate system used for the analysis of the signal transmission device 101. Hereinafter, a description will be given with reference to FIG.

  As shown in this figure, a mesh-shaped first conductor 111 having a repeating unit length d is disposed at z = 0, and a second conductor 121 is disposed at z = -D. And The portions other than the first conductor portion 111 and the second conductor portion 121 are filled with a dielectric having a dielectric constant ε. The mesh is a square mesh. The origin overlaps the mesh intersection, and the x and y axes are parallel to the mesh.

At this time, electromagnetic energy is localized in the vicinity of the mesh, and for the electric field E of the electromagnetic field,
E _z = Af (x, y, z) exp (-j (xk _x + yk _y ))
There is a traveling wave solution in the form of Where E _z is the z component of the electric field, A, k _x , k _y are constants, f (x, y, z) is a function with period d in the x direction and y direction, and k = (k _x , k _y , 0) is a wave vector (propagation vector) indicating the traveling direction of the traveling wave.

That is, for any x, y, z
f (x + d, y, z) = f (x, y, z) = f (x, y + d, z)
Is established.

Now, the electromagnetic field including E _z has a wave equation ΔE _z =-(ω ² / c ² ) E _{z in the} dielectric.
The filling,
k _x ² + k _y ² ≒ ω ² / c ²
It is.

Here, paying attention to the electromagnetic field at z> 0, f can be subjected to the following Fourier expansion due to the periodicity of f.
f (x, y, z) = Σ _{m, n} a (m, n) exp (2πj mx / d) exp (2πj ny / d) g (m, n, z)
Here, m and n are integers.

When d is sufficiently smaller than the electromagnetic wave length λ, 2π / d is sufficiently larger than ω / c, and (m, n) ≠ (0,0), the independence of each component of the Fourier expansion
u (m, n) = exp (2πj mx / d) exp (2πj ny / d) g (m, n, z)
Is approximately
Δu = (-(2πm / d) ^2- (2πn / d) ² + ∂ ² / ∂z ² ) u = 0
That is,
∂ ² / ∂z ² g ≒ (2π) ² (m ² + n ² ) / d ² g
Meet. Therefore,
g (m, n, z) ≒ B exp (-2π (m ² + n ² ) ^1/2 z / d)
It is. However, B is a constant. Therefore, for the component of (m, n) ≠ (0,0), the attenuation constant is d / (2π) or less.

  Here, the component of (m, n) ≠ (0,0) corresponds to a traveling wave component subjected to modulation of the period of the mesh structure.

Further, (m, n) = component corresponding to (0,0), i.e., the traveling wave component not modulated periodic mesh structure, the wavelength ^{_{λ = 2π / (k x 2}} + k y 2) 1 ^It reaches up to about ^{/ 2,} but its strength is small. This component is a component directly related to the term exp (−j (xk _x + yk _y )).

Due to such a theoretical background, the first conductor portion 111 is a mesh-shaped conductor having a square mesh shape of d = 2 [mm], the second conductor portion 121 is a foil-like conductor, and the first conductor portion 111 is When the average linear charge density σ = 1 [C / m] is given, the vertical electric field E _z [V / m] generated is multiplied by a constant 4πε.

  Similarly to the above, the first conductor portion 111 is disposed at z = 0, and the second conductor portion 121 is disposed at z = −D. The origin overlaps the mesh intersection, and the x and y axes are parallel to the mesh.

  FIG. 5 is an explanatory diagram showing the strength of the vertical electric field at various locations of the signal transmission device in this case. Hereinafter, a description will be given with reference to FIG.

  As shown in the upper three graphs, (x, y) = (0,0), (x, y) = (d / 2, d / 2), (x, y) = (d / 2 , 0), it can be seen that the vertical electric field becomes almost zero from around z = 1 [mm]. Further, the vertical electric field at y = 1 [mm] and z = 0.2 [mm] has a periodic pattern as shown in one graph at the bottom of the figure.

  Thus, when the repeating unit length of the mesh is 2 mm, the leakage of the electromagnetic field is considered to be about 1 mm, so if you bring the interface device closer than this distance, induction between the electromagnetic field becomes possible, It will be possible to send and receive signals.

  The electric field distribution when the second conductor 121 arranged at z = −D has the same mesh structure as that of the first conductor 111 arranged at z = 0 is based on the principle of symmetry, z = −D / The distribution is the same as that in the case where the foil-like second conductor portion 121 is arranged in 2 and the mesh-like first conductor portion 111 is arranged in z = 0. Therefore, the same conclusion as above can be obtained.

  As described above, it is sufficient to consider the order of d / (2π) to d / 2 to d as the thickness of the leaching region 141 and the facing region 151, and the interface in the leaching region 141 and the facing region 151 is sufficient. Communication can be performed by “soaking” the device.

Incidentally, sometimes leach to (m, n) = component corresponding to (0,0), the degree of electromagnetic wavelength ^{_{λ = 2π / (k x 2}} + k y 2) 1/2 in the communication layer However, near the surface of the communication layer, the intensity of this component is smaller than that of the other components and can be ignored.

  Note that the mesh does not necessarily have to be a square repetition, and may be various polygonal meshes. Further, the unit of the mesh need not be limited to the same shape, and may be a different shape as long as it has an appropriate mesh shape. In this case, the value corresponding to the above d can be considered as an average of the sizes of the meshes. Moreover, when these basic periods exist, the period can also be considered as d.

  In addition, a flat conductor having a plurality of honeycomb punch holes formed in a honeycomb shape may be used as the first conductor portion 111. In this case, the distance between the centers of the circles corresponds to d described above.

(Interface device)
In the above description, the loop antenna 202 and the dipole antenna 203 are used in the interface device. However, an interface device capable of emitting a directional electromagnetic field is proposed below.

  Note that the interface device proposed here is preferably used in combination with the signal transmission device 101 described above, but communication is possible if it can be in contact with an electromagnetic field that transmits a signal. Therefore, the situation where the interface device is used is not limited to the combination with the signal transmission device 101 described above.

  FIG. 6 is an explanatory diagram for explaining the directivity of such an electromagnetic field. Hereinafter, a description will be given with reference to FIG.

As shown in this figure, when the angle around the z-axis set perpendicular to the first conductor portion 111 and the second conductor portion 121 of the signal transmission device 101 is θ, the interface device according to the present embodiment emits. When the electromagnetic field φ ₁ is E _z , the z-axis counterclockwise magnetic field component is B _θ ,
E _z ≒ e (r, z) cosθ;
B _θ ≒ b (r, z) cos θ;
However, r ² = (x ² + y ² ).

(Example of interface device)
FIG. 7 is an explanatory diagram showing a schematic configuration of one embodiment of an interface device having such directivity. Hereinafter, a description will be given with reference to FIG.

  The interface device 601 can be broadly divided into an inner conductor portion 602, an outer conductor portion 603, and a route conductor portion 604.

  The internal conductor portion 602 is a conductor close to the signal transmission device 101 and has a belt-like shape having a width t. One end thereof is connected to the external conductor portion 603 and the other end is connected to the path conductor portion 604. Has been.

  The outer conductor portion 603 has a box-like structure and covers the inner conductor portion 602. The outer conductor portion 603 has an opening, and the path conductor portion 604 passes through the opening in a non-contact manner.

  Thereby, the current path of the outer conductor part 603 to the inner conductor part 602 to the path conductor part 604 is established. When a coaxial cable or a signal transmission / reception circuit is coupled to the outer conductor portion 603 and the path conductor portion 604 in the vicinity of the opening of the outer conductor portion 603 and the current flowing therethrough is changed, the electromagnetic wave is mainly shown in FIG. It will be emitted in the direction of the arrow.

  Note that θ = 0 is a direction along the inner conductor portion 602.

  As described above, since the outer conductor 603 covers the inner conductor 602 and the path conductor 604, unnecessary electromagnetic radiation to the outside of the interface device 601 can be prevented, so that the signal transmission device 101 can be efficiently connected. Electromagnetic energy can be exchanged.

  Note that portions other than the outer conductor portion 603, the inner conductor portion 602, and the route conductor portion 604 may be filled with a dielectric. Further, the outer conductor portion 603, the inner conductor portion 602, and the route conductor portion 604 may be any conductor as long as the surface thereof is the skin thickness, and the material inside thereof may be arbitrary.

  The mutually facing surfaces of the outer conductor portion 603 and the inner conductor portion 602 are preferably parallel to each other, and the inner conductor portion 602 is also preferably formed as a flat belt, but may have a step or unevenness.

  When the distance between the mutually facing surfaces of the outer conductor portion 603 and the inner conductor portion 602 is w, it is desirable that t does not become extremely larger than w. That is, it is desirable that t is approximately the same as w or t is equal to or less than w.

  FIG. 8 is an explanatory diagram showing the relationship between the values of t and w in the interface device 601. Hereinafter, a description will be given with reference to FIG.

  If t is equal to or less than w, the electromagnetic field generated by the current flowing through the internal conductor 602 is also generated outside the interface device 601 (shaded area on the right side of the figure), and signal transmission is performed. In combination with the traveling wave mode of the device 101, a traveling wave can be induced.

  On the other hand, if t increases and the entire bottom surface of the interface device 601 is covered, no signal can be transmitted or received.

  However, if there is a gap in a part of the bottom surface, coupling with the traveling wave mode of the narrow space 131 of the signal transmission device 101 occurs. Therefore, when impedance matching with a cable or communication circuit that drives the interface device 601 is performed, the inside of the interface device 601 is viewed from the opening of the external conductor portion 603 (which is a connection portion between the cable and the interface device 601). In order to reduce the impedance at the time, it may be considered that t is set larger than w.

  However, in that case, the ratio of the energy accumulated in the shaded area S on the left side of the figure to the electromagnetic energy generated outside the interface device 601 increases, and the first conductor portion 111 in contact with the area S and the dielectric in the area S Loss causes extra energy loss.

  Therefore, instead of increasing t itself, it is possible to employ a technique of matching the impedance by making the inner conductor portion 602 consist of a plurality of thin bands. FIG. 9 is an explanatory diagram showing an outline of the side of the internal conductor 602 that is connected to the path conductor 604 in such a case.

  As shown in the figure, the inner conductor 602 has a fork-like shape, and a plurality of thin bands extend from the path conductor 604 and are connected to the outer conductor 603 (not shown in the figure). It is constituted so that.

  Further, the length R of the inner conductor portion 602 (the distance between the point where the inner conductor portion 602 is connected to the outer conductor portion 603 and the point where the inner conductor portion 602 is connected to the path conductor portion 604 is R − m. ) And the wavelength λ of the electromagnetic field, it is desirable that R is not extremely smaller than λ.

Here, lambda is the wavelength ^{_{2π / (k x 2 + k}} y 2) of the traveling wave in the signal transmission device 101 is ^1/2.

  If 2πR << λ is established, the ratio of the energy radiated far away to the electromagnetic energy locally generated in the vicinity of the current path is remarkably reduced. Therefore, when electromagnetic waves are sent to the signal transmission device 101, This is because the ratio of energy loss (due to dielectric loss around the interface portion and metal resistance) increases.

  The interface device 601 having such a general shape can be combined with the signal transmission device 101 described above, and in addition to a signal transmission device in which two sheet-like conductors are opposed to each other and a hole is locally provided, It can also be combined with a signal transmission device in which a sheet-like dielectric is pasted on the sheet-like conductor. Therefore, the interface device 601 can be applied to various signal transmission devices.

  Hereinafter, the electromagnetic field generated by the interface device 601 will be examined in more detail.

  FIG. 10 is an explanatory diagram showing parameters of the shape of the interface device 601. Hereinafter, a description will be given with reference to FIG.

  The length of the internal conductor 602 (hereinafter also referred to as “proximity path” as appropriate) is R, the distance between the internal conductor 602 and the external conductor 603 is w, and the internal conductor 602 is connected to the path conductor 604. Let m be the length of further stretching beyond the connection point.

  FIG. 11 is an explanatory diagram showing a state of an electromagnetic field generated in the region S near the internal conductor portion 602 under such conditions.

  R, m, w, and t are adjusted so that the impedance of the coaxial cable connected to the interface device 601 and the impedance when the inside of the interface device 601 is viewed from the portion where the coaxial cable is connected. Here, there is a place where the reactance component of the impedance crosses zero when R≈λ / 4. Therefore, the length of R is set to a location where it crosses zero.

  Next, m, t, and w are adjusted together so that the real part of the impedance becomes the impedance of the coaxial cable.

Such a φ ₁ mode electromagnetic field is generated, and FIG. 12 is an explanatory diagram showing a state of the φ ₁ mode electromagnetic field. Hereinafter, a description will be given with reference to FIG.

  The rectangles shown in the upper part of the figure and the lower part of the figure correspond to the internal conductor portion 602. Further, the outer conductor portion 603 has a circular shape indicated by a dotted line.

The upper part of the figure shows the distribution of the magnetic field B _θ in the signal transmission device 101 in the direction of θ = 0, 180 °. The other direction has a shape obtained by multiplying the distribution of this figure by cos θ. In the near the center, but also present Dokei direction component B _r is the magnetic field, in the present invention, not play a major role as.

  The state of current flowing through the first conductor portion 111 in the signal transmission device 101 is shown. In this way, electromagnetic waves can be emitted simply by inducing current in one direction, which is convenient.

That is, the electromagnetic field generated by the interface device 601 of this embodiment has a large overlap with the asymmetric φ ₁ mode electromagnetic field, and electromagnetic waves are emitted simply by inducing a unidirectional magnetic field or current in the vicinity of the signal transmission device 101. The For this reason, it couple | bonds well with the electromagnetic field of the signal transmission apparatus 101 which the interface apparatus 601 of this embodiment produces.

(Interface devices of various shapes)
In the following, other types of interface devices will be further proposed. 13 and 14 are explanatory diagrams showing a schematic configuration of a circular interface device. Hereinafter, a description will be given with reference to FIG.

  The upper part of FIG. 13 is a bottom view of the interface device 601, and the middle part and the lower part are sectional views. FIG. 14 is a perspective view of the interface device 601.

  As shown in this figure, the outer conductor portion 603 of the circular interface device 601 has a shape in which a circular plate is provided with a cylindrical side surface, and the opposite side of the circular plate is edged. The inner conductor portion 602 is connected to the border.

  Further, the inner conductor portion 602 passes through the center of the circle and is connected to the path conductor portion 604 at a location corresponding to the center of the circle.

  The route conductor 604 passes through an opening provided near the center of the external conductor 603.

  The region covered with the outer conductor is filled with a dielectric and forms an insulator 605.

In this structure, it is easy to couple with a standing wave symmetric about the central axis of the interface device 601, and both the φ ₁ mode and the axially symmetric mode (a mode in which electromagnetic waves travel radially from the interface device 601 with equal energy density in all directions). Since it can be coupled, it can be considered that stable coupling with little location dependency is possible regardless of where the interface device 601 exists in the mesh.

  Further, in the present embodiment, the internal conductor portion 602 is formed in a cross shape, the center of the cross is connected to the path conductor portion 604, and the four ends of the cross are connected to the external conductor portion 603. May be.

  FIG. 15 is an explanatory view showing another embodiment. Hereinafter, a description will be given with reference to FIG.

  In the example shown in this figure, the internal conductor part 602 and the path conductor part 604 are integrated, and one loop-shaped conducting wire is connected at a connection point 606 of the disk-like external conductor part 603. Thus, while being covered with the outer conductor portion 603 functioning as a shield, a current path may be secured by looping.

  In addition, a form in which the inner conductor portion 602 is not connected to the outer conductor portion 603 can be considered. FIG. 16 is an explanatory diagram showing the relationship of parameters and the state of current and magnetic field in such a case. Hereinafter, a description will be given with reference to FIG.

  In a form in which the internal conductor portion 602 is not directly connected to the external conductor portion 603, the length R of the internal conductor portion 602 is desirably about half of the wavelength λ as shown in the upper part of the figure. The smaller distance among the width t of the internal conductor 602, the distance w between the internal conductor 602 and the external conductor 603, and the distance from the contact between the internal conductor 602 and the path conductor 604 to the end point of the internal conductor 602. Impedance matching is achieved by adjusting m.

  The three graphs in the lower part of the figure show the current distribution, magnetic field distribution, and electric field distribution. The shape of the graph of FIG. 11 is obtained by further extending the shape of the graph of FIG.

  In the case of the example shown in this figure, the length of the internal conductor portion 602 is set to half of the electromagnetic wave length λ. As shown in this figure, when looking at the impedance Z at a distance x from the right end of the inner conductor portion 602 toward the center of the interface device 601, when x = 0, the circuit is open and Z = ∞. However, it approaches Z = 0 when x = λ / 4.

  Therefore, this is the same as when the inner conductor portion 602 and the outer conductor portion 603 are short-circuited at the point of x = λ / 4. That is, at the wavelength λ, the inner conductor portion 602 and the outer conductor portion 603 equivalently form a series connection of a capacitor and a coil, so that it can be considered that a loop current path is formed.

  FIG. 17 is an explanatory diagram showing another method for performing impedance matching. Hereinafter, a description will be given with reference to FIG.

  As shown in this figure, the internal conductor portion 602 is cut halfway and is coupled capacitively.

  In this way, cutting the internal conductor portion 602 halfway has the same effect as connecting a capacitance (typically a capacitor) to the internal conductor portion 602 in series at the entrance of the interface device 601.

  In these cases, the current path is divided, but the vicinity of the dividing point functions as a capacitor, and it has been confirmed by experiments that a good connection is possible depending on the frequency band used for communication. That is, even in such a case, it can be considered that a current loop is formed for the non-DC component.

  In the case of the embodiment shown in FIG. 17, even if the interface device 601 has a small outer shape, there is an advantage that impedance matching can be easily performed by dividing.

  In the case of the embodiment shown in FIGS. 16 and 17, the intensity of electromagnetic wave radiation and reception is determined by the current flowing through the loop structure (including the division) and the path length, and the position of the division and the signal transmission device 101. The relative positional relationship between and does not directly determine its strength.

  As described above, in the above-described embodiment, since electromagnetic waves are two-dimensionally confined and communication is performed, energy required for information transmission to a certain distance is smaller than that in the case of so-called wireless communication.

  In addition, since the range in which energy is diffused is narrow, it is possible to supply power.

  Furthermore, it is considered that the multipath problem can be avoided and the speed can be increased as compared with wireless.

  In addition, it is possible to exchange signals between the interface device 601 and the signal transmission device 101 without electrical wiring.

(Experimental result)
The region covered with the outer conductor 603 of the interface device 601 was filled with a dielectric having a relative dielectric constant of 10, the frequency band was 2.4 GHz, R = 10 mm, and w = 1.6 mm. The connection position m of the path conductor portion 604 showed a good result even when m = 5 mm, but the experimental result when m = 0 mm is shown below. Further, the mesh period d = 15 mm.

  FIG. 18 is an explanatory diagram showing experimental parameters of the signal transmission device 101 and the interface device 601.

  The two interface devices 601 are arranged with a center interval of 10 [cm] and the 2.4 [GHz] signal having an amplitude of 1 [V] is transmitted from one to the other according to the specifications in FIG. The received voltage (S12) when the height (position in the z-axis direction) of the other interface device 601 was changed was observed. Also, a 50 [Ω] cable is connected to the interfaces on both sides, and the received voltage (S12) is measured using a network analyzer.

  In the specifications in this figure, “line width is 1 mm, mesh opening side is 14 mm”, which corresponds to the case where the mesh repeating unit d is 15 mm.

  FIG. 19 is a graph showing the results. By about 0.5 mm away, the received intensity decreased rapidly.

  In the next experiment, the interval between the two interface devices 601 was set to 6 [cm], and three directions of the receiving-side interface device 601 with respect to the mesh were considered. The received voltage S12 when a 1 V amplitude signal is input for each frequency between 1 GHz and 5 GHz is plotted in a graph. A 50Ω cable is connected to the two interfaces, and the received voltage (S12) is measured using a network analyzer.

  FIG. 20 is a graph showing the results. The left end of the horizontal axis of the graph corresponds to 1 GHz and the right end corresponds to 5 GHz. As shown in the figure, signals were observed in a wide band, confirming the effectiveness of the present invention. Each impedance is shown at the bottom of the figure. Since the coupling between the interface device 601 and the signal transmission device 101 is strong, it can be seen that the impedance in the 2.4 GHz band changes depending on the installation direction.

  FIG. 21 is a graph when the position of one interface device 601 is moved in the above case. As shown in the figure, a sufficiently strong signal was observed at any location.

  Now, various modifications of the above embodiment will be described below.

  FIG. 22 is an explanatory view showing a cross section of another embodiment of the interface device. Hereinafter, a description will be given with reference to FIG.

  The interface device 601 described in the lower part of the figure has a form corresponding to a combination of the communication device 201 and the loop antenna 202 described in FIG. It can be considered that the open side of the loop antenna 202 corresponds to the inner conductor portion 602, and the outer conductor portion 603 side of the loop antenna 202 corresponds to the path conductor portion 604.

  The interface device 601 described in the middle of the figure adopts a communication device 201 instead of the path conductor portion 604 and directly connects the outer conductor portion 603 and the inner conductor portion 602 with the communication device 201.

  The interface device 601 shown in the upper part of the figure is a form in which the inner conductor part 602 and the outer conductor part 603 are connected in the vicinity of the opening, and is similar to the embodiment shown in FIG. .

  In the interface device 601 of the present invention, the inner conductor 602 forms a part of a loop, and the loop is perpendicular to the surface of the signal transmission device 101 when the interface device 601 contacts the signal transmission device 101. It is a close coupling of electromagnetic fields. At this time, in order to prevent leakage of the electromagnetic field, an external conductor portion 603 covering these is prepared.

  FIG. 23 is a cross-sectional view showing the relationship between the interface device and another form of signal transmission device to which the interface device can be connected. Hereinafter, a description will be given with reference to FIG.

  The interface device 601 shown in the upper part of the figure is arranged near the opening of the conductor plate 901 having an opening, out of two conductor plates (which may be sheet-like conductors; the same applies hereinafter) 901 arranged opposite to each other. Has been. Since the electromagnetic wave is confined between the two conductor plates 901 as in the above embodiment, the signal can be transmitted and the interface device 601 communicates via the electromagnetic field that oozes from the opening.

  The interface device 601 shown in the lower part of the figure is similar to the above, but in this embodiment, a lower conductor plate 901 and a narrower information conductor 901 are arranged, and two conductor plates are provided. All 901 extend in a direction orthogonal to the figure, and have a belt-like shape as a whole. And although electromagnetic waves are confined in the area | region pinched | interposed into the two conductor plates 901, since a width | variety differs, as shown in this figure, an electromagnetic field oozes out when the lower conductor plate 901 is exposed. Therefore, using this, the interface device 601 performs communication.

  FIG. 24 is an explanatory diagram when a wired connection is made to the signal transmission device. Hereinafter, a description will be given with reference to FIG.

  As shown in this figure, the width of the electric wire is adjusted so that the impedance is matched immediately before the joint portion 903 where the mesh-shaped first conductor portion 111 of the signal transmission device 101 is connected to the core wire of the coaxial cable 902. Further, the outer conductor of the coaxial cable 902 is connected to the second conductor portion 121.

  Further, in the example shown in the figure, a strip-shaped conductor portion 904 is disposed on the edge of the first conductor portion 111, and a collective resistance or the like is provided between the strip-shaped conductor portion 904 and the second conductor portion 121. The electromagnetic wave absorber is arranged to prevent leakage of electromagnetic waves.

  FIG. 25 is an explanatory diagram showing an embodiment in which the first conductor portion of the signal transmission device is not in a mesh shape but in a stripe shape.

  As shown in the figure, the first conductor portion 111 of the signal transmission device 101 is disposed on the front side of the second conductor portion 121 in the figure, and the first conductor portion 111 is not in a mesh shape but in a stripe shape concentrated at the root. It is the shape of. If the distance between the stripes is d, the degree of oozing out of the electromagnetic wave is about d as in the above embodiment, so that the leaching region similar to that in the above embodiment can be formed.

(Dipole interface device)
As described above, a mesh-like signal transmission device (FIGS. 1 and 3 etc.), a signal transmission device (FIGS. 23, 25, etc.) having an aperture or a stripe structure by changing the size of the conductor In each case, an electromagnetic wave leaching region is formed.

  In FIG. 2, the aspect in which the antenna functions as an interface device by being brought close to such an electromagnetic wave leaching region has been described.

  In the following, a horizontal feed system that is one form in which the relationship between the interface device and the signal transmission device is arranged will be proposed, and a form using a dipole antenna having a configuration different from that of the interface device will be described.

  FIG. 26 is an explanatory diagram showing a basic idea type of the horizontal power feeding method for the signal transmission device. Hereinafter, a description will be given with reference to FIG.

  When the first conductor portion 111 and the second conductor portion 121 are arranged substantially in parallel and there is a region where the first conductor portion 111 does not overlap the second conductor portion 121, an electromagnetic wave leaching region may exist. Consider the signal transmission device 101 that will be. In this figure, a region where the first conductor portion 111 does not overlap the second conductor portion 121 is an opening 931 having a size 2r.

  In the horizontal power feeding method, a voltage is applied to the two connection regions 932 at the edge of the opening 931 provided in the first conductor portion 111, or a current is passed between the two, so that the signal is transmitted. This is a method for sending and receiving.

  As a method for applying a voltage to the connection region 932 or forming a current path, the interface device 601 can be directly connected as shown in FIG. As shown in b), indirect connection is possible only by bringing the electrode 933 of the interface device 601 close in the horizontal direction. Further, as shown in FIG. 7C, the connection region 932 and the electrode 933 of the interface device 601 can be arranged at intervals in the vertical direction of the drawing to be capacitively coupled.

  Typically, the two connection regions 932 have a line-symmetric shape with respect to a straight line passing through the center of the opening, as shown in FIG. Further, as shown in this figure, the connection region 932 and the electrode 933 are shaped so as to smoothly spread from the center of the opening 931 toward the edge, thereby reducing reflection and reducing the frequency characteristics. Can be improved.

  Note that the electrode 933 may have a simple line shape and a constant width and thickness.

  In the middle of a path formed by the connection region 932 and a device for applying voltage and generating current, an inductance such as a coil and a capacitance such as a capacitor may be appropriately combined in order to match impedance.

By such a horizontal power feeding method, the φ ₁ mode electromagnetic wave as described above with reference to FIG. 6 is generated.

  Since the waves radiated from the two connection regions 932 are driven in opposite phases, in order to improve the communication characteristics by strengthening the waves by interference, the wavelength λ of the electromagnetic wave in the gap region 131 is It is desirable that the size (diameter) 2r of the opening 931 and the total length L of the two electrodes 933 be about λ / 2. Actually, since the detour of the wave occurs at the edge of the opening 931 and the edge of the connection region 932, the optimal 2r and L sizes may deviate from λ / 2.

  The configuration of a dipole interface device (proximity connector) using an electrode 933 that is not directly connected as shown in FIG. 26B will be described below.

  The voltage or current between the two electrodes 933, the electric field or magnetic field, the electric flux density and the hourly density in each of the two connection regions 932 (these correspond to the generalized voltage and current and changes thereof). Are caused to interact by being directly connected or arranged in the vicinity, particularly when capacitively coupled or inductively coupled (in this case, it is necessary to be close to the wavelength of the electromagnetic wave). This interaction works greatly. And communication can be performed when both changes respond to each other.

  Here, when a charge is generated on the electrode surface in a state where the electrode is close to the conductive layer, a charge having an opposite sign is induced in the conductive layer. This is called a “capacitive coupling state”.

  Further, when a current is generated on the electrode surface, the current flows on the surface of the conductive layer so as to eliminate the magnetic field generated thereby from the inside of the conductive layer. This is called “inductively coupled state”.

  As a result of simultaneous charge distribution and current distribution on one electrode, they may occur simultaneously.

  FIG. 27 is an explanatory view showing a state of a cross section in which a dipole interface device is brought close to the signal transmission device. Hereinafter, a description will be given with reference to FIG.

  As shown in this figure, two linear electrodes (hereinafter referred to as “linear electrodes”) 933 are formed in the region of the first conductor portion 111 having an opening 931 as a region that does not overlap the second conductor portion 121. The interface device 601 having the proximity. The distance between the first conductor portion 111 and the second conductor portion 121 is d, and the gap region 131 is filled with a dielectric having a relative dielectric constant ε.

  An external communication device 934 is connected to the electrode 933. If the communication device 934 applies voltage or current to the electrode 933, transmission can be performed. If a change in the electromagnetic field in the leaching region near the opening 931 is detected, Can receive.

  The two linear electrodes 933 are preferably arranged separately on a straight line passing through the center of the opening 931. Here, the total length L of the interface device 601 composed of the two linear electrodes 933 is preferably about λ / 2, but detailed optimum conditions will be described later. Further, one length (feeding position) of the linear electrode 933 is x, and the width of the linear electrode 933 (in the case where the linear electrode 933 is constituted by an electric wire, this corresponds to the diameter of the thickness of the electric wire. .) Is D.

  The dipole-type interface device 601 shown in this figure operates on the same principle as the various loop antennas 202 and dipole antennas 203 using coaxial cables shown in FIG. The optimum conditions are different from those described above. This will be described in detail below.

  Let R be the impedance of the cable connected to the interface device 601 and the output impedance of the communication device 934. Further, the distance from the edge of the opening 931 to one end of the electrode 933 of the interface device 601 is defined as g. In the following, it is assumed that R = 50Ω, d = 3 mm, ε = 2.0, D = 0.1 mm, and the electromagnetic wave frequency band is 2.4 GHz.

If the size of the opening 931 is infinite and the lengths of the two linear electrodes 933 are both infinite, the characteristic impedance Z ₀ between the linear electrode 933 and the second conductor portion 121 is Z ₀ ≈ 260Ω. Further, the impedance between the two linear electrodes 933 is about 2 Z ₀ .

  Here, it is assumed that the first conductor portion 111 does not exist.

When L is small, the absolute value of the impedance between the two linear electrodes 933 is larger than 2 Z ₀ , indicating a capacitive property.

  From this point, when L is increased, when a certain value of L≈λ / 2 is reached, the impedance between the two linear electrodes 933 becomes a real number and the absolute value becomes a minimum value. At this time, a standing wave is generated in the vicinity of the linear electrode 933.

  The magnetic field of the standing wave is substantially perpendicular to the linear electrode 933 and substantially parallel to the surface of the second conductor portion 121 in the space between the linear electrode 933 and the second conductor portion 121.

  In general, when n is an integer, a state in which the impedance between the two linear electrodes 933 is a real number appears periodically in the vicinity of L≈ (λ / 2) n.

  Under such a premise, L, x, d, D, g, and the distance between the linear electrodes 933 are adjusted so that the impedance between the linear electrodes 933 matches the driving impedance R. Can do.

  When the impedance is matched in this way, for example, when a cable is connected to the interface device 601, the energy of the electromagnetic wave traveling through the cable is radiated to the narrow space 131 without being reflected.

When the absolute value of the impedance between the end of the linear electrode 933 and the nearest point of the first conductor portion 111 is larger than Z ₀ (for example, when g is large), when matching occurs in the vicinity of the linear electrode 933 ( Consider the electric field distribution during resonance. FIG. 28 is an explanatory diagram showing a state of an electric field distribution in a resonance state of n = 1. Hereinafter, a description will be given with reference to FIG.

  At resonance, the electric field in the gap region 131 can be expressed as E exp (jωt + θ) using the real number E, and is substantially perpendicular to the boundary surface of the gap region 131. In this figure, the distribution of E at this time is shown. As shown in the figure, the electric field distribution E in the vicinity of the linear electrode 933 crosses zero at the center.

As in the case where the absolute value of the impedance between the nearest point of the first conductor portion 111 is greater than Z ₀ , such as when g is large, the total length L of the linear electrode 933 is greater than the opening 931. If the coupling between the linear electrode 933 and the first conductor portion 111 is sufficiently strong, the situation is different. This case will be described below.

  For easy understanding, it is assumed that the interface device 601 has a symmetric shape, and a spaced portion between the linear electrodes 933 is disposed at the center of the opening 931. FIG. 29 is an explanatory diagram showing the positional relationship between the interface device 601 and the signal transmission device 101 in such a case. Hereinafter, a description will be given with reference to FIG.

  The condition for impedance matching when the coupling between the linear electrode 933 and the first conductor portion 111 is sufficiently strong depends more on the radius r of the opening 931 than on the total length L of the linear electrode 933. .

When g is large, the impedance z when looking out from the end point of the linear electrode 933 satisfies | z | >> Z ₀ (open end condition). On the other hand, in the case shown in the figure, a point P (black circle in the figure) facing the edge of the opening 931 of the linear electrode 933 and a point Q (black in the figure) between the second conductor 121 facing this point. In some cases, the impedance z between the two dots becomes | z | << Z ₀ (short-circuit condition).

  When the short-circuit condition is satisfied, if r is selected so as to satisfy 2r≈λ / 2, the impedance between the linear electrodes 933 becomes a real number, and the absolute value thereof is maximized.

  Optimum performance can be obtained by adjusting each parameter so that the impedance at this time becomes equal to R.

In the above example, when the impedance at the end point of the electrode 933 is about the same as Z ₀ , the optimum condition may be greatly different from L≈λ / 2 or 2r≈λ / 2. It is also possible to select appropriate parameters.

  In any of the above cases, even if the impedance is not perfectly matched, electromagnetic waves can be transmitted and received with a certain level of power, and the parameters can be changed as appropriate according to the application.

  The linear electrode 933 may employ a wire-shaped material with a constant thickness as the linear electrode 933, but gradually and gradually spreads outward as shown in FIG. 26 (c). It is good also as such a shape.

  In the latter case, even if the relative position between the interface device 601 and the opening 931 is shifted, the reflection coefficient does not change abruptly, and the impedance between the linear electrodes 933 does not change extremely. Therefore, the connection with the signal transmission device 101 is smooth, and strong reflection at a specific portion of the linear electrode 933 is suppressed, and signal transmission in a wide band is possible.

  FIG. 30 is an explanatory view showing cross sections of various shapes of the interface device of the present embodiment. Hereinafter, a description will be given with reference to FIG.

  FIGS. (I) and (II) correspond to the embodiment shown in FIGS. 27 and 29. FIGS. (III) and (IV) are different from the embodiment shown in FIG. Thus, a shield 935 covering the linear electrode 933 is prepared.

  In this drawing (III), the linear electrode 933 is configured independently of the shield 935, and in this drawing (IV), one of the linear electrodes 933 is connected to the shield 935. Further, although not shown in the drawing, both of the linear electrodes 933 may be connected to the shield 935.

  When the shield 935 is used, electromagnetic waves can be prevented from being radiated to the side opposite to the signal transmission device 101. In this figure (IV), when g is sufficiently large, L≈λ / 4 is the optimum length, and at this time, the impedance between the drive terminals is minimized.

  In addition, when a shield 935 is provided (not shown) with respect to this figure (I) and both end points of both of the linear electrodes 933 are connected to the shield 935, g> 0 and L≈ λ / 2 is the optimum length, and the impedance between the drive terminals becomes maximum at that time.

  FIG. 31 is an explanatory view showing the shape of a folded dipole interface device. Hereinafter, a description will be given with reference to FIG.

  As shown in the figure, the total length L of the interface device 601 is smaller than the diameter 2r of the opening 931.

  Further, only one bending electrode 936 is prepared by bending both end portions of the linear conductor in parallel with the remaining portion. When the communication device 934 is connected to this, the shape is such that the communication device 934 is inserted by using a long rectangular side as an electrode and dividing a part of the longitudinal side.

  The form shown in this figure has a shape like a loop antenna as shown in FIG. 2 at first glance, but actually, an electromagnetic field similar to that of two dipole antennas is formed, and the driving impedance is increased. However, communication characteristics similar to those of the simple dipole interface device 601 as described above are exhibited.

  The folded portion may be rounded. It is also possible to adopt a curved shape such as an elliptical shape instead of a rectangular shape.

Here, the features of these embodiments will be summarized.
(1) The total length L of the linear electrode 933 has an optimum value in the vicinity of λ / 2, but signals can be transmitted and received at other lengths.
(2) The optimum value of the power feeding position x is not necessarily L / 2, and can be appropriately adjusted according to the application and mode of implementation.
(3) There are few restrictions on the thickness and shape of the linear electrode 933. Typically, a linear shape is adopted, but a bent shape or a V-shape may be used. Further, an asymmetric structure (for example, one having a wide band, the other having a narrow band, etc.) in which the shapes of the two linear electrodes 933 are different may be employed.
(3) A coil or a resonator may be inserted as part of the linear electrode 933. When g is large, L can be reduced by inserting a coil. In addition, when a resonator is inserted, driving at a plurality of frequencies is possible.
(4) The size 2r of the opening 931 may be larger or smaller than L. Further, the center position of the opening 931 and the center position of the full length of the linear electrode 933 do not have to coincide with each other.
(5) In addition to being usable in the mesh type signal transmission device 101 as shown in FIG. 1, it can also be applied to a case where a conductor wire is stretched in the opening 931 to form a mesh. .

(Sensor device)
As described above, by arranging the interface device 601 in the evanescent region where the electromagnetic field leaks out in various signal transmission devices 101, communication with the communication device 934 connected to the interface device 601 is possible.

  Therefore, an RF tag is adopted as the communication device 934, and the interface device 601 and the RF tag combined together are referred to as “sensor tags”.

  If multiple sensor tags are prepared and each ID is different, which sensor tag exists in the evanescent area and which sensor tag exists outside the evanescent area is connected via the signal transmission device 101. It can be detected by an RF tag reader or various computers. Therefore, a sensor device to which these are applied can be configured.

Since it detects whether or not it is in the evanescent region, in the configuration of the sensor device using this,
(1) Detecting a change in the distance between the signal transmission device 101 and the sensor tag (2) Two types are possible: detecting a change in dielectric constant between the signal transmission device 101 and the sensor tag.

  First, the first method will be described. FIG. 32 is an explanatory diagram showing a cross section of the sensor device by detecting a change in the distance between the signal transmission device 101 and the sensor tag. Hereinafter, a description will be given with reference to FIG.

  As shown in the figure, an elastic body 941 is disposed on the leaching region 141 side of the signal transmission device 101 so as to cover the first conductor portion 111 and the narrow space region 131.

  The elastic body 941 keeps the distance between the sensor tag 942 and the signal transmission device 101 so that the sensor tag 942 is arranged on the leaching region 141 side when the elastic body 941 has a natural length to which no external pressure is applied.

  When an external pressure is applied, the elastic body 941 is deformed and the sensor tag 942 enters the inside of the leaching region 141. Depending on which sensor tag 942 enters the leaching area 141, it is possible to detect which position is applied with an external force.

  Further, the amount of deformation of the elastic body 941 in the vicinity of the sensor tag 942 (and thus the magnitude of the external force / pressure) can be obtained based on the strength of the signal in communication with the sensor tag 942. The greater the strength of the signal, the more the sensor tag 942 enters the leaching area 141, and the greater the deformation amount.

  As the elastic body 941, rubber, sponge, or the like can be adopted, or a metal having a beam structure shape can be adopted as shown in the figure.

  In addition, instead of the elastic body 941, if a material such as SMA or bimetal that deforms due to temperature change is adopted, it becomes a temperature sensor, and if a material that deforms due to light, humidity, chemicals, etc. is adopted, each sensor Become.

  Next, the second method will be described. FIG. 33 is an explanatory diagram showing a cross section of the sensor device by detecting a change in dielectric constant between the signal transmission device 101 and the sensor tag. Hereinafter, a description will be given with reference to FIG.

  As shown in this figure, a dielectric 943 is disposed on the signal transmission device 101 side of the sensor tag 942, and an interface device 601 to which an RF tag is connected is attached thereon. When the sensor tag 942 is arranged on the surface of the signal transmission device 101, the interface device 601 is arranged in the leaching region 141 of the signal transmission device 101 in an environment where the dielectric 943 exists. .

  If a material whose dielectric constant varies depending on light, heat, temperature, chemical substance, or pressure is used as the material of the dielectric 943, the electrical coupling (communication electromagnetic wave) between the interface device 601 and the signal transmission device 101 due to external factors. Transmission intensity) changes.

  By combining this information with the ID detection of the RF tag, the location of the signal transmission device 101 and the detected value at that location can be acquired.

  FIG. 34 shows an example in which these sensor tags 942 are arranged on the surface of the signal transmission device 101. As shown in the figure, the sensor tag 942 can be arranged at a favorite place.

  In this case, it is assumed that a dielectric 943 of an appropriate size is pasted on the bottom surface of the sensor tag 942 (the surface on the side where the signal transmission device 101 is disposed) and can be freely disposed. By using the sensor unit, it is possible to configure a sensor unit that detects different objects.

  When the detection target is constant, a sheet-like dielectric 943 can be attached to the surface of the signal transmission device 101, and the sensor tag 942 can be disposed at a desired position.

  As described above, according to the present invention, it is possible to provide a sensor device that can transmit various measurement results to the signal transmission device by being arranged near the surface of the sheet-shaped signal transmission device. .

It is explanatory drawing which shows schematic structure of the signal transmission apparatus used in combination with the interface apparatus which concerns on embodiment of this invention. It is explanatory drawing which shows the mode of the interface apparatus of the simplest shape with respect to the signal transmission apparatus of this embodiment. It is explanatory drawing which shows schematic structure of the signal transmission apparatus used in combination with the interface apparatus which concerns on embodiment of this invention. It is explanatory drawing which shows the mode of the coordinate system used for the analysis of a signal transmission apparatus. It is explanatory drawing which shows the intensity | strength of the vertical electric field of the various places of a signal transmission apparatus. It is explanatory drawing for demonstrating the directivity of an electromagnetic field. It is explanatory drawing which shows schematic structure of one Embodiment of the interface apparatus which has directivity. It is explanatory drawing which shows the relationship between the value of t and w in an interface apparatus. It is explanatory drawing which shows the general form of the side connected to the path | route conductor part of an internal conductor part. It is explanatory drawing which shows the parameter of the shape of an interface apparatus. It is explanatory drawing which shows the mode of the electromagnetic field produced in the area | region of the vicinity of an internal conductor part. It is explanatory drawing which shows the mode of the electromagnetic field of (phi) ₁ mode. It is explanatory drawing which shows schematic structure of a circular interface apparatus. It is explanatory drawing which shows schematic structure of a circular interface apparatus. It is explanatory drawing which shows other embodiment of an interface apparatus. It is explanatory drawing which shows the relationship of a parameter, and the mode of an electric current and a magnetic field. It is explanatory drawing which shows the method of performing impedance matching. It is explanatory drawing which shows the experimental parameter of a signal transmission apparatus and an interface apparatus. It is a graph which shows received power when an interface apparatus is gradually separated from a signal transmission apparatus. It is a graph which shows the other received power at the time of changing the direction with respect to one mesh of two interface apparatuses. It is a graph which shows the receiving power of the other at the time of moving one position of two interface apparatuses. It is explanatory drawing which shows the cross section of other embodiment of an interface apparatus. It is sectional drawing which shows the relationship between an interface apparatus and the signal transmission apparatus of the other form which can connect this. It is explanatory drawing in the case of performing wired connection to a signal transmission apparatus. It is explanatory drawing which shows embodiment which made the 1st conductor part of the signal transmission apparatus the stripe shape instead of the mesh shape. It is explanatory drawing which shows the basic idea type of the horizontal electric power feeding system with respect to a signal transmission apparatus. It is explanatory drawing which shows the mode of the cross section which made the dipole type interface apparatus adjoin to the signal transmission apparatus. It is explanatory drawing which shows the mode of the electric field distribution of the vicinity of a linear electrode. It is explanatory drawing which shows the positional relationship of an interface apparatus and a signal transmission apparatus. It is explanatory drawing which shows the cross section of the various shapes of the interface apparatus of this embodiment. It is explanatory drawing which shows the shape of a folding | turning dipole type | mold interface apparatus. It is explanatory drawing which shows the cross section of the sensor apparatus by detecting that the distance of a signal transmission apparatus and a sensor tag changes. It is explanatory drawing which shows the cross section of the sensor apparatus by detecting the change of the dielectric constant between a signal transmission apparatus and a sensor tag. It is explanatory drawing which shows the example which arrange | positions a sensor tag on the surface of a signal transmission apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Signal transmission apparatus 111 1st conductor part 121 2nd conductor part 131 Narrow area | region 141 Exudation area | region 151 Opposite area | region 201 Communication circuit 202 Loop type antenna 203 Dipole type antenna 601 Interface apparatus 602 Internal conductor part 603 External conductor part 604 Path | route conductor part 605 Insulator part 606 Connection point 901 Conductor plate 902 Coaxial cable 903 Joint part 904 Band-shaped conductor part 931 Open hole 932 Connection area 933 Electrode 934 Communication device 935 Shield 936 Bending electrode 941 Elastic body 942 Sensor tag 943 Dielectric

Claims (7)

A sheet-like signal transmission device having a region for propagating the electromagnetic field therein and leaching the electromagnetic field in the vicinity of the surface;
An interface device that is arranged separately from the signal transmission device and belongs to a region where the electromagnetic field is leached, and is capable of communicating with the signal transmission device via the leached electromagnetic field;
A sensor device comprising:
When the interface device is provided with identification information and belongs to a region where the electromagnetic field is leached, the interface device is transmitted to the signal transmission device so that the interface device is moved to the region where the electromagnetic field is leached. A sensor device characterized by detecting that it belongs. The sensor device according to claim 1,
The identification information is given to the interface device by an RF tag. The sensor device according to claim 1 or 2,
An elastic body is disposed between the signal transmission device and the interface device to separate them,
A sensor device, characterized in that, when it is detected that the interface device belongs to a region where the electromagnetic field is leached, it is detected that pressure is applied near the interface device. The sensor device according to claim 1 or 2,
An elastic body is disposed between the signal transmission device and the interface device to separate them,
When it is detected that the interface device belongs to a region where the electromagnetic field is leached, the deformation amount of the elastic body in the vicinity of the interface device is detected based on the strength of communication between the interface device and the signal transmission device. A sensor device. The sensor device according to claim 3 or 4,
The elastic device is a rubber, sponge, or metal beam structure. The sensor device according to claim 1 or 2,
Between the signal transmission device and the interface device, a dielectric whose dielectric constant changes due to a change in physical quantity is arranged,
A sensor device, wherein when detecting that the interface device belongs to a region where the electromagnetic field is leached, a change in the physical quantity is detected based on the strength of communication between the interface device and the signal transmission device. The sensor device according to claim 6,
The interface device is configured integrally with the dielectric,
The said dielectric and the said signal transmission apparatus are comprised so that attachment or detachment is possible. The sensor apparatus characterized by the above-mentioned.

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