JP2009003560A - Tag communication system and gate device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tag communication system and a gate device for preventing the reading omission of an RFID tag which is present at a position where it is difficult to read from a scan antenna, and for making the scale of the whole system compact, and for reduing cost. <P>SOLUTION: A reader/writer 3 and a scan antenna 4 are installed at one side of a gate 8, and a reflection plate 5A and a reflection plate 5B and a reflection plate 5C are respectively installed at the upper side of the gate 8, the other side of the gate 8 and the lower side of the gate 8. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a tag communication system and a gate device, and more particularly, to a tag communication system and a gate device that can satisfactorily communicate with an RFID tag in a position that is difficult to read with an antenna alone.

  Recently, in the logistics industry, a reader / writer, which is a tag communication device, and an antenna are installed at a gate, and each package is loaded from an SKU (Storage Keeping Unit: a lump of luggage loaded on a pallet). A so-called RFID system has been adopted in which an attached RFID tag is read to manage the loading and unloading of packages.

  According to this RFID system, for example, when a reader / writer having an antenna connected to a gate that is a cargo entry / exit gate is installed and a query wave is transmitted from this antenna, a response wave is transmitted from the SKU that passes through this gate. Since it is transmitted and data such as ID (Identification) can be automatically read, it is possible to improve the efficiency of physical distribution operations as compared with the prior art.

  Here, in order to reduce reading omission of the RFID tag, for example, a tag communication system described in Patent Document 1 has been devised in which the communication area is widened. In this tag communication system, the communication area is widened by using a scan antenna that can scan a beam of radio waves to be transmitted. Furthermore, by scanning the beam so that the surface specified by the scanning direction of the beam intersects the reflecting surface where the strongest reflected wave is generated, the traveling direction of the beam is changed toward the reflecting surface by scanning. In the incommunicable part, the radio wave intensity of the direct wave is different from the radio wave intensity of the reflected wave from the reflecting surface, multipath interference can be suppressed, and the tag communication device and the RFID tag can communicate with each other. It can cover a wide communication area. As described above, in the tag communication system described in Patent Document 1, by scanning the radio wave beam and scanning so as to suppress multipath interference, the communication area can be widened while eliminating the incommunicable portion. As a result, reading leakage from the RFID tag is eliminated.

  However, in this tag communication system, it is possible to reduce reading omissions with respect to the RFID tag that is visible from the scanning antenna, but radio waves are not transmitted to the RFID tag that is hidden by other workpieces. Although it is hard to reach and is prone to read omission, this tag communication system is also insufficient to improve this omission.

  A configuration is also possible in which a plurality of scan antennas are installed so that even RFID tags hidden by other workpieces can be read. However, if a plurality of scan antennas are installed, the system scale increases and costs increase. In addition to this, multipath interference also increases, and another problem arises that communication between tags cannot be performed satisfactorily.

JP 2006-20083 A

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to prevent reading of an RFID tag that is difficult to read from a scan antenna, and to reduce the size of the entire system and reduce the cost. Another object is to provide a tag communication system that can be realized.

  The present invention relates to a tag communication system that performs radio communication with an RFID tag attached to an object, and transmits a radio wave to be received by the RFID tag, and a scan antenna capable of changing the direction of the radio wave to be transmitted. A tag communication device that is connected to the scan antenna and controls communication between the scan antenna and the RFID tag, and at least one reflector that reflects radio waves transmitted from the scan antenna toward the RFID tag And.

  The present invention is a tag communication system for reading an RFID tag at a position that is difficult to read by a scan antenna. For this purpose, a radio wave transmitted from the scan antenna using a reflector is reflected by the reflector, and the reflected wave is directed to the RFID tag at a position difficult to read. As a result, it is difficult to read with the scan antenna alone, and RFID tags with reading omission are eliminated.

  Here, the “object” means an article such as a luggage or a product, but also includes humans and animals. For example, when the object is a human being, when a plurality of humans pass through the gate, an RFID tag attached to a person close to the scanning antenna can be read, but at a position away from the scanning antenna and to a plurality of persons. Since it is difficult to read an RFID tag attached to a person passing through a hidden place, the present invention can be applied to this case.

  Also, “attached” means that the RFID tag can be moved together with the object, for example, when the object is a package, an RFID tag is attached, or the RFID tag is attached with a tag. It means a state of being attached to, and various forms can be applied depending on the object.

  As the “RFID tag”, for example, a passive type RFID tag that does not have a power source such as a battery, operates a circuit with power transmitted from a reader / writer by radio waves, and performs wireless communication with the reader / writer, a battery An active type RFID tag having a power source is included.

  The “tag communication device” is, for example, a reader / writer or a reader / writer that can communicate with an RFID tag.

  The “scan antenna” is composed of, for example, a phased array antenna that can scan a beam of radio waves transmitted by electronic control at high speed, and a plurality of antenna elements and a plurality of phase shifters connected to each of the plurality of antenna elements. And one distribution synthesizer connected to all of the plurality of phase shifters. The radio wave input to the distribution synthesizer is distributed to the phase shifter for each antenna element, and after a desired phase change is made in each phase shifter, it is radiated from each antenna element. Are radiated strongly in a direction in which all are in phase, that is, in a direction in which the phases of the sine waves coincide.

  Further, the plurality of antenna elements may be, for example, ones in which patch antennas are linearly arranged or two-dimensionally arranged. If a plurality of antennas are configured from the patch antenna, it is preferable because the scan antenna can be manufactured thin and the manufacturing cost can be kept low. Further, if a plurality of antennas are arranged in a two-dimensional arrangement, for example, a plurality of antenna elements are arranged in a circular shape or a matrix shape on the same plane, scanning can be performed so as to draw a circle.

  The “reflector” reflects the radio wave from the scan antenna and travels toward the RFID tag, and a reflective surface is formed on the surface where the radio wave comes in by applying a metal finish or applying a radio wave reflector. The surface is configured to reflect radio waves. In short, this reflector may be of any material and shape as long as it can reflect the radio wave from the scan antenna toward the RFID tag. When the width of the reflector is the same as the wavelength of the radio wave, or 3/4, 1/2 of the wavelength, the electromagnetic wave resonance phenomenon is caused on the reflecting surface to attenuate, and the power of the reflected wave is reduced. Will fall. Therefore, the width of the reflector is preferably set to be equal to or greater than the wavelength of the radio wave. Furthermore, the reflecting surface of the reflecting plate can be formed in various shapes such as a planar shape, a secondary paraboloid, a cylindrical surface, and an elliptical surface. If the shape of the reflecting surface is a secondary paraboloidal surface, a cylindrical surface, an elliptical surface, or the like, the diffusion of reflected waves from the reflecting surface can be minimized as compared with a planar reflecting surface. In addition, if the reflecting surface is a secondary paraboloid that is recessed inward, the reflected wave exhibits parallel radiation characteristics. If the reflection surface is a cylindrical surface or an ellipsoidal surface that is recessed inward, the radiation characteristic that the reflected wave converges is exhibited. In some cases, the shape of the reflecting surface may be a secondary parabolic surface, a cylindrical surface, an elliptical surface, or the like protruding outward.

  The reflector may be configured to reflect a radio wave transmitted from the scan antenna toward the RFID tag and to change a reflection direction of a reflected wave reflected toward the RFID tag.

  As a configuration for changing the reflection direction of the reflected wave, for example, various methods such as providing a rotation mechanism capable of changing the angle of the reflection plate or making the reflection surface of the reflection plate a curved surface can be applied. Since the direction of the radio wave beam is scanned by the scan antenna, the reflection direction of the reflected wave can be changed depending on the position where the radio wave is reflected if the reflection surface is formed of a curved surface.

  Various installation locations of the scan antenna and the reflection plate are considered as follows.

  For example, the scan antenna is installed on one side of a gate that is an entrance of the object, and the reflector is installed on at least one of the upper side, the other side, and the lower side of the gate. It may be configured. Since the scanning antenna scans the beam of radio waves, if one reflector is placed, the reflected wave can be obtained by this reflector. However, if a plurality of reflectors are placed, the reflected wave can be obtained as many as the number placed. This makes it possible to widen the communication area and improve the reading leakage of the RFID tag.

  Further, the scan antenna may be installed on the upper side of the gate that is an entrance of the object, and the reflection plate may be installed on one side or both sides of the gate.

  The scan antenna may be installed on the upper side of the gate that is the entrance of the object, and the reflector may be installed on the lower side of the gate.

  The length of the reflecting plate in the object entering / exiting direction may be longer than the depth length of the gate in the object entering / exiting direction.

  Furthermore, the tag communication system of the present invention can be used not only when installed at a gate, but also when installed on a table on which products to be purchased beside a cash register, such as a retail store. In this case, for example, the scan antenna is provided on a table on which the object is placed, and a direction in which radio waves are transmitted is set above the table, and the reflector transmits the scan plate. What is necessary is just to comprise so that it may be provided in the transmission direction of an electromagnetic wave.

  Further, the present invention is a gate device that performs wireless communication with an RFID tag attached to an object, the gate being an entrance / exit of the object, a scan antenna installed above the gate, And a reflecting plate installed on both sides.

  Further, the present invention is a gate device that performs radio communication with an RFID tag attached to an object, the gate being an entrance / exit of the object, a scan antenna installed on one side of the gate, and the gate And a reflection plate installed on the other side.

  The reflector may be configured to reflect a radio wave transmitted from the scan antenna toward the RFID tag and to change a reflection direction of the reflected wave reflected toward the RFID tag. Good.

  As described above, according to the present invention, the beam of the radio wave transmitted by the scan antenna is scanned, and this beam is reflected by the reflector toward the object. As a result, it is possible to prevent reading of an RFID tag that is difficult to read from the scan antenna, to reduce the scale of the entire system, and to reduce the cost.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Hereinafter, in the first embodiment to the fourth embodiment, a case where the tag communication system of the present invention is applied to luggage entry / exit management is shown, and in the fifth embodiment, the tag communication system of the present invention is a store. The case where it is installed next to the cash register and applied to the purchase price calculation of the product is shown. However, the tag communication system of the present invention is not limited to these embodiments.

<First Embodiment>
1 is a plan view showing a schematic configuration of a tag communication system according to a first embodiment of the present invention, FIG. 2 is a block diagram showing a schematic configuration of an RFID tag, and FIG. 3 is a block diagram showing a schematic configuration of a reader / writer, FIG. 4 is a schematic diagram illustrating an outline of the scan antenna, and FIG. 5 is a schematic diagram illustrating a scan state of the scan antenna.

  As shown in FIG. 1, a tag communication system 1 in this embodiment includes a reader / writer (tag communication device) 3, a scan antenna 4, and reflection plates 5A to 5C (hereinafter collectively referred to as “reflection plate 5”). Thus, storage management of the SKU 60 that is a lump of a plurality of packages 6A to 6F (hereinafter collectively referred to as “package 6”) stacked on the pallet 7 is performed. The RFID tags 2 are attached to the packages 6A to 6F constituting the SKU 60, and the reflectors 5 are used to reflect radio waves to the RFID tags 2 that are difficult to read from the scan antenna 4. I try to read it. The above is the outline of the tag communication system in the present embodiment, which will be described in detail below.

  As shown in FIG. 2, the RFID tag 2 includes an antenna unit 20 and a wireless communication IC 21. As the RFID tag 2 of this type, for example, the above-described passive type or active type is used.

  The antenna unit 20 receives radio waves from the reader / writer 3 as a power source for operating the wireless communication IC 21. The antenna unit 20 converts radio waves received from the reader / writer 3 into radio signals and transmits the radio signals to the radio communication IC 21, and converts radio signals from the radio communication IC 21 into radio waves and transmits the radio signals to the reader / writer 3. is there. An antenna, a resonance circuit, or the like is used for the antenna unit 20.

  The wireless communication IC 21 stores data from the reader / writer 3 based on a signal received from the reader / writer 3 through the antenna unit 20, or transmits the stored data to the reader / writer 3 through the antenna unit 20. It is something to do. As shown in FIG. 2, the wireless communication IC 21 includes a power supply unit 211, a wireless processing unit 212, a control unit 213, and a memory unit 214.

  The power supply unit 211 rectifies the induced voltage generated when the antenna unit 20 receives radio waves with a rectifier circuit, adjusts the induced voltage to a predetermined voltage with the power supply circuit, and then supplies the rectified voltage to each unit of the wireless communication IC 21. . For the power supply unit 211, a bridge diode, a voltage adjusting capacitor, or the like is used.

  The wireless processing unit 212 converts a wireless signal received from the outside via the antenna unit 20 into an original format, transmits the converted data to the control unit 213, and is suitable for wireless transmission of the data received from the control unit 213. The converted radio signal is transmitted to the outside via the antenna unit 20. As the wireless processing unit 212, an A / D (Analog to Digital) conversion circuit, a D / A (Digital to Analog) conversion circuit, a modulation / demodulation circuit, an RF circuit, or the like is used.

  The control unit 213 controls the operations of the various configurations described above in the wireless communication IC 21 in an integrated manner. The control unit 213 includes a logical operation circuit, a register, and the like, and functions as a computer. And operation control of various composition is performed by making a computer run a control program. For example, this program may be used by reading a program installed in a ROM (Read Only Memory) or the like of the memory unit 214, or may be used from the reader / writer 3 via the antenna unit 20 and the wireless processing unit 212. The program may be downloaded, installed in the memory unit 214, and executed.

  In particular, the control unit 213 stores data from the reader / writer 3 in the memory unit 214 based on data received from the reader / writer 3 via the antenna unit 20 and the wireless processing unit 212, or is stored in the memory unit 214. The data is read out and transmitted to the reader / writer 3 via the wireless processing unit 212 and the antenna unit 20.

  The memory unit 214 includes a semiconductor memory such as the above-described ROM, SRAM (Static RAM), or FeRAM (ferroelectric memory). The contents stored in the memory unit 214 include the above-described control program, various other programs, and various data such as an ID. Since the wireless communication IC 21 uses the radio wave transmitted from the reader / writer 3 as a power source, it is desirable to use a non-volatile memory such as a ROM or a memory with low power consumption such as an SRAM or FeRAM.

  Next, the configuration of the reader / writer and the scan antenna will be described with reference to FIGS. FIG. 3 is a block diagram illustrating a schematic configuration of the reader / writer, FIG. 4 is a schematic diagram illustrating an overview of the scan antenna, and FIG. 5 is a schematic diagram illustrating a scan state of the scan antenna. FIG. 3 also schematically shows a state in which wireless communication with the RFID tag 2 is performed via the scan antenna 4.

  The reader / writer 3 includes an external communication unit 31, a tag communication control unit 32, a transmission unit 33, a reception unit 34, and a scan antenna control unit 35. The reader / writer 3 is configured to be connected to the scan antenna 4 and wirelessly communicate with the RFID tag 2. Has been.

  The external communication unit 31 stores the result of communication with the RFID tag 2 such as the ID (Identification) of the RFID tag 2 read by the reader / writer 3 and information indicating whether or not the writing to the RFID tag 2 has been successful. It is configured to transmit to an external device such as a computer, and to receive write information (transmission command information) from the external device and a command (command) from the external device to the RFID tag 2. Also, examples of the interface standard with an external device include USB (Universal Serial Bus), IEEE 1394, Ethernet (registered trademark), and the like.

  The tag communication control unit 32 receives the transmission command information transmitted from the external device via the external communication unit 31 and transmits it to the transmission unit 33. The tag communication control unit 32 stores a scan pattern table (not shown). The scan pattern table includes data defining the power and phase of each antenna element 40A, 40B, and 40C of the scan antenna 4, and the power and phase defined for each antenna element 40A, 40B, and 40C, respectively. By setting electrically, the scan pattern of the scan antenna 4 is generated.

  That is, the scan angle of the scan antenna 4 is set by this scan pattern table. As shown in FIG. 5, the scan angle is an inclination angle of the beam M measured with reference to the broadside direction (direction perpendicular to the arrangement direction of the antenna elements 40A, 40B,... 40K). In the present embodiment, the clockwise direction (α) in the figure is a positive value, and the counterclockwise direction (β) is a negative value. In the present embodiment, the scan angle is set in the direction of each of reflectors 5A to 5C, which will be described later, and the direction of the surface on which the RFID tag 2 is attached in the packages 6A to 6C. That is, as shown in FIG. 1, the scan angle is set in the direction of each of the transmission waves SW1 to SW5. Since FIG. 5 is a schematic diagram for explaining how to scan with the scan antenna 4, only α, β and binary values are described as scan angles.

  The tag communication control unit 32 reads the scan angle information from the scan table and transmits the scan angle information to the scan antenna control unit 35.

  The transmission unit 33 converts transmission command information transmitted from the tag communication control unit 32 into a format suitable for wireless transmission, and transmits the converted wireless signal (transmission command) to the outside via the scan antenna 4. Processing such as modulation and amplification of transmission command information is performed. The receiving unit 34 converts a radio signal (received data) received from the outside via the scan antenna 4 into an original format, and transmits the converted data to the tag communication control unit 32. Processing such as demodulation is performed.

  The scan antenna control unit 35 receives the scan angle information from the tag communication control unit 32, transmits a scan control signal to the scan antenna 4 based on the received scan angle information, and generates radio waves radiated from the scan antenna 4. The direction of the beam M is controlled.

  FIG. 4 is an explanatory diagram showing an outline of the scan antenna 4. The scan antenna 4 has a configuration in which a plurality of antenna elements 40 are linearly arranged and a variable phase shifter (phase shifter) 41 is connected to each antenna element 40. In FIG. 5, the number of antenna elements 40 is three, but the number of antenna elements 40 is not limited to three. The antenna elements 40 are not limited to a linear array, and may be arranged in a two-dimensional array. When the number of antenna elements 40 is increased, the width of the beam M becomes narrower. In FIG. 4, the number of antenna elements 40 is an arbitrary number, and a scanning method in the beam direction in the scan antenna 4 will be described below with reference to FIG. 4.

  When all the antenna elements 40A, 40B,... 40K transmit radio waves with the same phase, the radio waves radiated from the scan antenna 4 are in the broadside direction (arrangement direction of the antenna elements 40A, 40B,... 40K). It propagates as a plane wave in the direction perpendicular to On the other hand, in order to incline the propagation direction of the radio wave from the broadside direction by an angle θ (rad), the phase of the radio wave transmitted by each antenna element 40A, 40B,. Just shift it.

As shown in FIG. 4, the wavelength of the radio wave to be transmitted or received is λ (m), the distance between the reference antenna element 40A and the kth antenna element 40K is d _k (m), and the broken line in FIG. Of the shown equiphase surfaces, if the distance between the equiphase surface passing through the reference antenna element 40A and the kth antenna element 40K is l _k (m), the kth relative to the phase of the reference antenna element 40A. The phase shift ψ _k of the antenna element 40K is as follows.

[Formula]
ψ _k = (l _k / λ) × 2π = (d _k × sin θ / λ) × 2π

  In this way, the scan antenna 4 can direct the radio wave beam M in the target direction by shifting the phase of the signal so that each of the phase shifters 41A, 41B,... 41K satisfies the above equation. On the other hand, when receiving a radio wave, the direction of the received radio wave can be determined by detecting a phase shift of each antenna element 40A, 40B,. In the present embodiment, the reader / writer 3 connected to the scan antenna 4 configured as described above is provided on one side of the gate 8.

  The reflection plate 5 reflects the transmission waves SW1 to SW5 transmitted from the scan antenna 4 and travels toward the RFID tag 2, and has a metal finish or radio wave on the surface on which the transmission waves SW1 to SW5 come. A reflection surface is formed by applying a reflective agent, and radio waves are reflected by the reflection surface.

  In the present embodiment, the reflecting plate 5 is composed of three reflecting plates 5A to 5C provided on the gate 8. The reflecting plate 5A is on the upper side of the gate 8, and the reflecting plate 5B is on one side on which the reader / writer 3 is provided. On the opposite side, the reflecting plate 5C is provided below the gate 8 respectively. Further, the direction of each reflection surface is such that each transmission wave SW1, SW2 and SW5 transmitted from the scan antenna 4 is reflected by each reflection plate 5A to 5C and proceeds to the RFID tag 2 attached to the luggage 6. Is set.

  When the scan antenna 4 is installed at the position shown in FIG. 1, the RFID 2 attached to the upper surfaces of the packages 6A and 6D, the RFID tag 2 attached to the sides of the packages 6D to 6F, and the RFID tag 2 attached to the side of the packages 6C. Is difficult to read even if the scan wave is scanned by the scan antenna 4, and reading leakage is likely to occur. Therefore, in the present embodiment, the following reflectors 5A to 5C are provided on the gate 8 to prevent reading leakage of the RFID tag 2 that is likely to cause reading leakage.

  In other words, in FIG. 1, the transmission wave SW1 is reflected by the reflecting plate 5B and the reflected wave RW2 is reflected by the reflecting plate 5B so that the reflected wave RW1 is reflected by the reflecting plate 5A and directed toward the upper surface of the SKU 60. Each of the reflecting plates 5A to 5F is reflected so that the transmission wave SW5 is reflected by the reflecting plate 5C and the reflected wave RW5 is directed to the RFID tag 2 attached to the package 6C of the SKU 60 so that 6F faces the surface of the surface. The direction of the 5C reflecting surface is set. Since the reflecting plate 5C is installed on the floor surface below the gate 8, in this case, a position where the transmission wave SW5 of the scan antenna 4 is reflected by the reflecting plate 5C may be set.

  In the present embodiment, the reflecting plates 5A and 5B are formed with flat reflecting surfaces, and are attached to the gate 8 in a fixed state without moving the reflecting surfaces, but rotate to the reflecting plates 5A and 5B. A mechanism may be provided so that the direction of the reflecting surface can be changed. In this way, the communication range can be further expanded, and the effect of preventing reading omission is increased.

  Next, the operation of the tag communication system 1 configured as described above will be described. When the reader / writer 3 is activated, the scan antenna 4 repeatedly transmits the transmission waves SW1 to SW5 in the direction shown in FIG. Then, the transmission wave SW1 is reflected by the reflecting plate 5A to become a reflected wave RW1, and proceeds to the upper surface side of the SKU 60. Similarly, the transmission wave SW2 is reflected by the reflecting plate 5B to become a reflected wave RW2, and travels to the upper surface side of the SKU 60. Similarly, the transmission wave SW2 is reflected by the reflecting plate 5B, and the reflected wave RW2 travels in the direction of the surface on which the loads 6D to 6F of the SKU 60 are exposed. Similarly, the transmission wave SW5 is reflected by the reflecting plate 5C, and the reflected wave RW5 travels in the direction of the RFID tag 2 attached to the luggage 6C of the SKU 60. On the other hand, the transmission waves SW3 and SW4 travel directly toward the SKU 60 without being reflected by any of the reflection plates 5A to 5C.

  In the present embodiment, the reflecting plates 5A and 5B are fixed and described as having a constant reflecting direction. However, a rotating mechanism is provided in the reflecting plates 5A and 5B so that the direction in which the reflecting surface faces is changed as needed. Variations to be configured are also possible. In this case, the reflecting plates 5A and 5B may be moved simultaneously when the reader / writer is activated.

  As described above, in the present embodiment, only one scan antenna 4 is installed, and the reflected wave from the reflectors 5A to 5C is used for the RFID tag 2 that is difficult to read for the scan antenna 4. I read it. As a result, the scale of the entire system can be reduced, the cost can be reduced, and the communicable area can be widened.

  In the first embodiment, the reader / writer 3 and the scan antenna 4 are installed on one side of the gate 8, the reflective plate 5A is installed on the upper side, the reflective plate 5B is installed on the other side, and the reflective plate 5C is installed on the lower side. The writer 3, the scan antenna 4 and the reflection plate 5 may be installed as follows. Modification examples of the installation locations of the respective configurations will be described as second to fourth embodiments. In the following description, the components such as the scan antenna 4, the reader / writer 3, the reflector 5 and the gate 8 are the same as those in the first embodiment, so only the positional relationship of each component will be described, and the description and operation of each component. Description is omitted.

Second Embodiment
FIG. 6 is a plan view showing a schematic configuration of the tag communication system according to the second embodiment of the present invention and the gate device according to the first embodiment of the present invention. In the following, the tag communication system 1A will be described. The present invention includes a gate 8, a scan antenna 4 installed on the upper side of the gate 8, and reflectors 5D and 5E installed on both sides on one side of the gate 8. The gate device is realized.

  In the tag communication system 1A of this embodiment, the reader / writer 3 and the scan antenna 4 are installed on the upper side of the gate 8, the reflection plate 5D is on one side of the gate 8, that is, the left side of the gate 8 in FIG. The other side, that is, the right side of the gate 8 in FIG. Also in this embodiment, the reflecting plate 5D and the reflecting plate 5E may be attached to the gate 8 in a fixed state, or may be attached so as to change the reflecting surface together with a rotating mechanism (not shown).

  Also in this embodiment, when the reader / writer 3 is activated, the transmission waves SW1 to SW4 of the scan antenna 4 scan as shown in the figure. Then, the transmission wave SW1 is reflected by the reflecting plate 5D to become a reflected wave RW1, and travels in the direction of the surface on which the packages 6A to 6C of the SKU 60 are exposed. Similarly, the transmission wave SW4 is reflected by the reflecting plate 5E to become a reflected wave RW4, and travels in the direction of the surface on which the packages 6D to 6F of the SKU 60 are exposed. On the other hand, the transmission waves SW2 and SW3 travel in the direction of the upper side surface of the SKU 60 without being reflected by any reflector.

<Third Embodiment>
FIG. 7 is a side view showing a schematic configuration of a tag communication system 1B according to the third embodiment of the present invention. In this embodiment, as in the second embodiment, the reader / writer 3 and the scan antenna 4 are installed above the gate 8, but the scanning direction is repeatedly scanned in the illustrated traveling direction (arrow X). And the point that the reflecting plate 5F is installed under the gate 8. In this case, the length L1 (length in the object entry / exit direction) of the reflector 5F is set to be longer than the length L2 (depth length in the object entry / exit direction) of the gate 8. As a result, a communication path is configured with the RFID tag 2 (the RFID tag 2 attached to the baggage 6C in FIG. 7) in the front and rear and lower sides of the SKU 60, in particular, the RFID tag 2 facing downward. Wide area can be achieved.

  Also in this embodiment, when the reader / writer 3 is activated, the transmission waves SW1 to SW3 are transmitted as shown in the figure, SW1 proceeds to the upper side of the SKU 60, and SW2 proceeds to the surface of the luggage 6A to 6C of the SKU 60, SW3 is reflected by the reflecting plate 5F to become a reflected wave RW3, and the RFID tag 2 attached to the luggage 6C is read by the reflected wave RW3.

<Fourth embodiment>
FIG. 8 is a plan view showing a schematic configuration of a tag communication system 1C according to the fourth embodiment of the present invention and a gate device according to another embodiment of the present invention. In the following description, the tag communication system 1C will be described. The tag communication system 1C includes a gate 8, a scan antenna 4 installed on one side of the gate 8, and a reflector 5G installed on the other side of the gate 8. A gate device according to another embodiment is realized. In the present embodiment, as in the first embodiment, the reader / writer 3 and the scan antenna 4 are installed on one side of the gate 8, that is, on the left side of the gate 8 in FIG. That is, the right side of the gate 8 and the reflecting plate 5C are installed on the lower side of the gate 8, and the reflecting plate 5G is installed so as to be rotatable using a rotation mechanism (not shown). And different. The reflecting plate 5G can be rotated, that is, the direction of the reflected wave can be changed, and the direction of the reflecting surface can be changed. Thereby, the number of reflectors can be reduced while ensuring the same communication area as in the first embodiment.

  In this case, when a rotation mechanism (not shown) attached to the reader / writer 3 and the reflecting plate 5G is activated, the scan antenna 4 repeatedly scans the transmission waves SW1 to SW3 as shown in the figure, and the reflecting plate 5G also has the direction of the reflecting surface. It rotates repeatedly so that changes. Then, the transmission wave SW1 is reflected by the reflecting plate 5G to be reflected waves RW11 to RW13, and RW11 advances to the upper side of the SKU 60, and RW12 advances in the direction toward the surface on which the packages 6D to 6F of the SKU 60 are exposed. On the other hand, the RW 13 travels in the direction of the reflecting plate 5C and is reflected by the reflecting plate 5C to become a reflected wave RW131 and travels in the direction of the luggage 6F. On the other hand, SW2 and SW3 travel in a direction toward the surface on which the loads 6A to 6C of the SKU 60 are exposed.

<Fifth Embodiment>
The tag communication system 1D according to the present embodiment is a case where the tag communication system 1D is installed beside a cash register in a store and applied to the purchase price calculation of a product.

  In the present embodiment, the scan antenna 4A is installed in a table 9 on which products are placed, and a reflecting plate 5H and a reflecting plate 5I are installed above the table 9, respectively. In FIG. 9, products (objects) 6 </ b> G to 6 </ b> L to be purchased are placed on the base 9. The RFID tags 2 are attached to the products 6G to 6L, and the reader / writer 3 similar to the above is connected to the scan antenna 4A.

  In the present embodiment, for example, the reader / writer 3 is activated when a store is opened. Then, the transmission waves SW1 to SW4 are repeatedly scanned in the direction of the figure from the scan antenna 4. In this state, when the products 6G to 6L to be purchased are placed on the base 9, the transmission wave SW1 is reflected by the reflecting plate 5H to become a reflected wave RW1 and travels in the direction of the products 6G and 6H and is attached to each. Read the RFID tag 2. Similarly, the transmission wave SW3 is reflected by the reflecting plate 5I to become a reflected wave RW3 and travels in the direction of the product 6I. On the other hand, the transmission wave SW2 and the transmission wave SW4 do not reflect on any of the reflectors 5H and 5I, the transmission wave SW2 travels in the direction of the products 6J and 6K, reads the RFID tag 2 attached to each, and SW4 is the product. It proceeds toward 6L and reads the RFID tag 2 attached thereto.

  As described above, if the tag communication system 1D according to the present embodiment is installed on the stand 9 or the like installed next to a cash register such as a store, the total price of the product can be calculated without inputting the price of the product by the cash register. It is convenient because it can be done. Further, by using the reflectors 5H and 5I, the problem of field holes is solved, communication with more RFID tags 2 is possible, and the communication area can be widened.

1 is a plan view showing a schematic configuration of a tag communication system according to a first embodiment of the present invention. The block diagram which shows schematic structure of a RFID tag. The block diagram which shows schematic structure of a reader / writer. The schematic diagram which shows the outline | summary of a scanning antenna. The schematic diagram which shows the scanning state of a scanning antenna. The top view which shows schematic structure of the tag communication system which concerns on 2nd Embodiment of this invention. The side view which shows schematic structure of the tag communication system which concerns on 3rd Embodiment of this invention. The top view which shows schematic structure of the tag communication system which concerns on 4th Embodiment of this invention. The top view which shows schematic structure of the tag communication system which concerns on 5th Embodiment of this invention.

Explanation of symbols

1, 1A-1D tag communication system 2 RFID tag 3 reader / writer (tag communication device)
4 Scan antenna 5A-5I Reflector 60 SKU
6A-6F Luggage (object)
6G-6L product (object)
7 palettes 8 gates 9 units SW1 to SW4 transmission waves RW1 to RW4 reflected waves

Claims (10)

A tag communication system that performs wireless communication with an RFID tag attached to an object,
A radio wave for receiving by the RFID tag, and a scan antenna capable of changing the direction of the radio wave to be transmitted;
A tag communication device connected to the scan antenna and performing communication control between the scan antenna and the RFID tag;
A tag communication system comprising: at least one reflector that reflects radio waves transmitted from the scan antenna toward the RFID tag. The reflector is
The tag communication according to claim 1, wherein a radio wave transmitted from the scan antenna is reflected toward the RFID tag, and a reflection direction of a reflected wave reflected toward the RFID tag can be changed. system. The scan antenna is
Installed on one side of the gate which is the entrance of the object,
The reflector is
The tag communication system according to claim 1 or 2, wherein the tag communication system is installed in at least one of the upper side, the other side, and the lower side of the gate. The scan antenna is
It is installed on the upper side of the gate that is the gateway of the object,
The reflector is
The tag communication system according to claim 1 or 2, wherein the tag communication system is installed on one side or both sides of the gate. The scan antenna is
It is installed on the upper side of the gate that is the gateway of the object,
The reflector is
The tag communication system according to claim 1, wherein the tag communication system is installed under the gate. The length of the object in / out direction of the reflector is:
The tag communication system according to claim 5, wherein the tag communication system is longer than a depth length of the gate in the object entering / exiting direction. The scan antenna is
The object is provided on a table on which the object is placed, and the direction in which radio waves are transmitted is set above the table,
The reflector is
The tag communication system according to claim 1, wherein the tag communication system is provided in a transmission direction of a radio wave transmitted by the scan antenna. A gate device that performs wireless communication with an RFID tag attached to an object,
A gate that is an entrance of the object;
A scanning antenna installed above the gate;
A gate device comprising: reflectors installed on both sides of the gate. A gate device that performs wireless communication with an RFID tag attached to an object,
A gate that is an entrance of the object;
A scanning antenna installed on one side of the gate;
And a reflector installed on the other side of the gate. The reflector is
10. The reflection direction of the reflected wave reflected from the radio wave transmitted from the scan antenna toward the RFID tag and reflected toward the RFID tag can be changed. Gate device.

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