JP2009009205A - Metal-adaptable rfid tag, rfid tag-equipped metal pallet, and data communication system and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To heighten durability of an RFID tag, and to improve communication efficiency. <P>SOLUTION: In this data communication system, a metal-adaptable RFID tag 20 stuck with an inlet sheet 22 is installed on a slope of a triangle pole-shaped spacer 21 made of a nonconductor such that it is stored inside an L-shaped frame 13 of a metal pallet 10, an electric wave emitted toward an RFID tag-equipped metal pallet 2 from a reader/writer 3 is received, and an electric wave returned by the metal-adaptable RFID tag 20 is made to be reflected by the L-shaped frame 13 to improve gain. Thereby, the returned electric wave is certainly captured by the reader/writer 3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a metal-compatible RFID tag attached to a metal surface, a metal pallet with an RFID tag to which the tag is attached, and a data communication system and method using the metal pallet with an RFID tag.

  For example, in the field of logistics, a work platform called a pallet is used when transporting luggage by trucks, loading or storing luggage in factories or warehouses, and so on. As a general pallet shape, there are known types such as a flat type and a box type, and there are various types of materials such as wooden, resin or metal. An RFID tag that can communicate with the reader / writer is attached to the pallet, and data management of the luggage placed on the pallet is performed.

  In the case of a metal pallet among such pallets, when the RFID tag is directly attached to the metal surface, the antenna of the RFID tag comes close to the metal surface. Then, an eddy current is generated on the metal surface near the antenna by the electromagnetic field from the reader / writer, and the demagnetizing field due to this eddy current blocks the electromagnetic field necessary for communication, so the communication efficiency between the reader / writer and the RFID tag is improved. It gets worse. Therefore, conventionally, a spacer made of synthetic resin, rubber, or the like is bonded to the back surface of the RFID tag, and the distance between the RFID tag antenna and the metal surface is separated to suppress the generation of eddy currents, thereby improving the communication efficiency. .

  FIG. 5 is a diagram showing an example in which a conventional RFID tag is attached to a metal pallet. As shown in the figure, conventionally, in order to perform communication with the distance from the reader / writer to the RFID tag 50 as small as possible, the RFID tag 50 is connected to a support frame 52 on the outermost side of a metal pallet 51 via a spacer 53. It was attached. Further, in order to increase the communication efficiency between the reader / writer and the RFID tag 50, it is necessary to increase the thickness of the spacer 53 and to ensure a sufficient distance between the antenna of the RFID tag 50 and the metal surface of the support frame 52. Further, in order to increase the reception sensitivity of the antenna of the RFID tag 50, a magnetic sheet 54 containing a magnetic material such as ferrite is attached to the back surface of the spacer 53.

  As described above, conventionally, when attaching the RFID tag 50 to the metal pallet 51, the RFID tag 50 is attached via the thick spacer 53. Therefore, the entire RFID tag 50 including the spacer 53 is enlarged, and the work such as loading is performed. There was a problem that sometimes got in the way. Further, since the RFID tag 50 protrudes greatly on the outside of the metal pallet 51, the RFID tag 50 comes off from the support frame 52 due to contact with an operator or surrounding luggage, or the RFID tag 50 due to an impact at the time of contact. There was a problem that was broken. Furthermore, since the magnetic sheet 54 is expensive, there is also a problem that the cost required for system construction increases significantly when the magnetic sheet 54 is attached to each RFID tag 50.

  In addition, Patent Document 1 below discloses a tag mounting tool in which a rectangular parallelepiped or semi-cylindrical spacer is attached to an RFID tag, and the periphery of the spacer is covered with a metal plate. In order to attach the RFID tag to the metal pallet, it is necessary to separately provide a dedicated attachment hole on the pallet side, and the attachment location is also limited.

JP 2006-338361 A

  The present invention has been made in view of such problems, and an object of the present invention is to increase the durability of the RFID tag, improve the communication efficiency, and can be manufactured at a low cost. Another object is to provide a metal pallet with an RFID tag to which the tag is attached and a data communication system and method using the metal pallet with an RFID tag.

  In order to achieve the above object, the invention according to claim 1 of the present application is directed to a triangular prism spacer made of a non-conductive material, a conductive antenna provided on the slope of the spacer, and an IC connected to the antenna. A metal-compatible RFID tag characterized by comprising a chip. As the material for the spacer, synthetic resin, rubber, or the like is suitable.

  Here, the “RFID tag” in the present invention includes those generally used synonymously with this, for example, a non-contact IC tag, a wireless tag, an RFID data carrier, etc., and the communication system is an electromagnetic induction system. Or any of a radio wave system may be sufficient.

  The invention according to claim 2 of the present application is characterized in that, in the metal-compatible RFID tag according to claim 1, an inlet sheet on which an antenna and an IC chip are mounted is attached to the slope of the spacer.

  In the invention according to claim 3 of the present application, in the metal-compatible RFID tag according to claim 1 or 2, the length from the apex of the spacer to the antenna is set within a range of 0.1 to 0.7λ. It is characterized by that. The length from the top of the spacer to the antenna is determined by the frequency to be used. For example, the length is set to about 32 to 224 mm in the UHF (950 MHz) band and about 12 to 84 mm in the microwave (2.45 GHz) band. .

  Further, the invention according to claim 4 of the present application is made of a metal material, and a pedestal on which a load is placed, an L-shaped frame that supports the pedestal, and an inner wall surface of the L-shaped frame with a side surface of the spacer facing each other. An RFID tag-attached metal pallet comprising the attached metal-compatible RFID tag according to any one of claims 1 to 3 is provided.

  The invention according to claim 5 of the present application performs data communication between the metal pallet with RFID tag according to claim 4 and the metal-compatible RFID tag of the metal pallet with RFID tag by an induction electromagnetic field or radio wave. A data communication system comprising a communication device is provided.

  Here, the “communication device” in the present invention means a device capable of wirelessly reading and writing data with respect to the RFID tag, and includes a reader, a writer, and a reader / writer.

  In addition, the invention according to claim 6 of the present application is directed to the metal pallet with RFID tag according to claim 4 and receives an induction electromagnetic field or radio wave radiated from the communication device and is returned from the metal-compatible RFID tag. Alternatively, the present invention provides a data communication method that performs data communication by reflecting radio waves on an L-shaped frame.

  According to the present invention, an L-shaped frame of a metal pallet functions as a reflector of a so-called corner reflector antenna, and an induction electromagnetic field or radio wave radiated from a communication device toward a metal pallet with an RFID tag is converted into a metal-compatible RFID. When the tag replies, the induction electromagnetic field or radio wave is reflected to the L-shaped frame and becomes unidirectional so that the gain is improved. Therefore, the reduction of the communication distance is suppressed, and the reader / writer and the metal RFID tag are Can perform stable data communication.

  In addition, since it is possible to attach the metal-compatible RFID tag and spacer so as to fit inside the L-shaped frame, it does not interfere with work such as loading, and the metal-compatible RFID tag or spacer is placed outside the metal pallet. Therefore, it is possible to prevent the metal-compatible RFID tag from falling out or fail due to an impact at the time of contact, and to improve the durability of the metal-compatible RFID tag.

  Furthermore, the mounting position of the metal-compatible RFID tag can be arbitrarily determined depending on how to load and load, or the arrangement relationship with the reader / writer, and the metal-compatible RFID tag can be easily attached to the metal pallet. In addition, since there is no need to attach an expensive magnetic sheet or the like to the back surface of the metal-compatible RFID tag, a metal pallet with an RFID tag can be manufactured at a low cost, and the cost required for system construction can be greatly reduced.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 is an overall view showing a data communication system of the present invention, FIG. 2 is a partially enlarged view showing a main part of a metal pallet with an RFID tag of the present invention, and FIG. 3 is a side view showing a metal-compatible RFID tag of the present invention. FIG. 4 is an explanatory view showing the operation of the metal-compatible RFID tag of the present invention.

  As shown in FIG. 1, the data communication system 1 is a system for efficiently managing data related to the luggage 30 when transporting, loading, or storing the luggage 30 at a distribution site. The communication device is constructed of a handy terminal type reader / writer 3.

  The metal pallet 2 with an RFID tag is formed by detachably attaching a metal-compatible RFID tag 20 to a metal pallet 10.

  The metal pallet 10 of the present embodiment is a flat pallet, a pedestal 11 on which the luggage 30 is placed, a support frame 12 that supports the ends of the pedestal 11, and an L-shaped frame that supports both sides of the pedestal 11. 13 and all these parts are made of metal such as iron or aluminum. Further, two rows of insertion ports 14 for inserting lift claws are provided between the support frames 12 and 12 so that the metal pallet 10 can be lifted by a handlift or a forklift during loading.

  As shown in enlarged views in FIGS. 2 and 3, the metal-compatible RFID tag 20 is formed by attaching an inlet sheet 22 to a spacer 21.

  The spacer 21 is sized to fit inside the L-shaped frame 13 of the metal pallet 10 and has a triangular prism shape made of a right-angled isosceles triangle having a bottom apex angle α of 90 °. And non-conductive material such as rubber.

  In the present embodiment, the inlet sheet 22 functions as an RFID tag employing a radio wave system, and an antenna 23 and an IC chip 24 are mounted on a base material made of a synthetic resin film such as PET.

  The antenna 23 is formed by pattern-printing a conductive paste on the surface of the substrate by printing such as screen, ink jet, or intaglio, or etching or plating copper foil or aluminum foil. The conductive paste is a paste that can be printed by mixing and dispersing conductive particles such as gold, platinum, silver, copper, palladium, nickel, tin, lead, and indium in a resin binder of vinyl resin or phenol resin. It is a thing. The antenna 23 receives a radio wave from the reader / writer 3 and generates an electromotive force of the IC chip 24. Therefore, the antenna 23 is formed in a left-right symmetric planar dipole antenna type suitable for the radio wave system, and a pair of power feeding portions are terminals of the IC chip 24. It is connected to the. The total length of the planar dipole antenna is set to about half wavelength (λ / 2), that is, about 157 mm if the frequency of the radio wave used is UHF (950 MHz) band, and about 62 mm if the microwave (2.45 GHz) band is used. The

  The IC chip 24 is an electronic component that performs non-contact data communication with the reader / writer 3 by radio waves, and includes a CPU, ROM, RAM, and EEPROM. The CPU analyzes the signal received from the antenna unit of the reader / writer 3, executes the process, and transmits the execution result to the reader / writer 3. The ROM is a read-only memory that stores an execution program of the CPU, the RAM is a working memory that temporarily stores data, and the EEPROM is a non-volatile memory that rewrites data communicated with the reader / writer 3.

  As shown in FIG. 3, the inlet sheet 22 is attached to the triangular prism slope 21 a of the spacer 21 with an adhesive 25. As the adhesive 25, an epoxy or urethane adhesive can be used. The antenna 23 on the inlet sheet is arranged in parallel to the ridgeline of the spacer 21, and the distance from each of the two metal plates constituting the L-shaped frame 13 to the antenna 23 is equal to each other. Further, the length L from the apex 21b of the spacer 21 to the antenna 23 is 0.1 to 0.7λ as the shortest distance, that is, about 32 to 224 mm if the frequency of the radio wave used is a UHF (950 MHz) band. In the case of the (2.45 GHz) band, it is set to about 12 to 84 mm.

  The reason for setting the above length is that in the case of a corner reflector antenna having an apex angle α of 90 ° as in the present invention, the most gain is obtained when the distance L to the frame serving as the reflector is 0.1 to 0.7λ. This is because it has been theoretically proved that it can be kept high.

  As described above, in the data communication system 1 of the present invention, when the metal-compatible RFID tag 20 is attached to the metal pallet 10 as the configuration of the metal pallet 2 with the RFID tag, the inner wall surface of the L-shaped frame 13 is attached. Thus, the side surfaces 21c of the triangular prism-shaped spacers 21 are attached so as to face each other. Thus, when radio waves are radiated from the reader / writer 3 toward the metal pallet 2 with an RFID tag, the two metal plates constituting the L-shaped frame 13 function as reflectors of the corner reflector antenna.

  That is, as shown in FIG. 4A, the RFID tag provided with the normal dipole antenna has the same degree of directivity on the front and back of the antenna. Therefore, as shown in FIG. 2B, the return radio wave A from the metal-compatible RFID tag 20 in the front direction is radiated as it is toward the reader / writer 3. Further, the return radio wave B from the metal-compatible RFID tag 20 in the back direction passes through the spacer 21 and enters the L-shaped frame 13, and is reflected by the two metal plates of the L-shaped frame 13 with the same incident angle. Reflected at the corner and emitted toward the front. Therefore, when the return radio waves A and B are combined, the single directivity in the front direction is enhanced and the gain is improved, so that the return radio waves A and B are reliably captured by the reader / writer 3. Accordingly, problems such as a decrease in communication distance that occurs when a normal RFID tag is directly attached to a metal surface are eliminated, and data communication regarding the luggage 30 is reliably performed between the reader / writer 3 and the metal-compatible RFID tag 20. Can do.

  Further, since the spacer 21 can be attached so as to fit inside the L-shaped frame 13, the entire size of the metal-compatible RFID tag 20 including the spacer 21 can be reduced, and these parts are obstructive even during work such as loading. do not become. Moreover, since the metal-compatible RFID tag 20 does not protrude from the outside of the metal pallet 10, the metal-compatible RFID tag 20 falls off from the metal pallet 10 due to contact with an operator or surrounding luggage, or an impact at the time of contact. Thus, it is possible to prevent the failure of the metal-compatible RFID tag 20 and the durability of the metal-compatible RFID tag 20 is improved.

  Furthermore, the mounting position of the metal-compatible RFID tag 20 can be arbitrarily determined with respect to the metal pallet 10 depending on how to load or load the cargo or the arrangement relationship with the reader / writer 3, and the mounting work is also easily performed. It becomes possible. Further, since it is not necessary to attach an expensive magnetic sheet or the like to the back surface of the metal-compatible RFID tag 20, the metal pallet 2 with an RFID tag can be manufactured at low cost, and the cost required for system construction is greatly reduced.

  In the present embodiment, the radio wave method is adopted as a communication method between the reader / writer 3 and the metal-compatible RFID tag 20, but an induction electromagnetic method can be adopted instead. In addition, although the metal-compatible RFID tag 20 is obtained by attaching the inlet sheet 22 to the spacer 21, the antenna 23 and the IC chip 24 may be directly mounted on the spacer 21. Furthermore, the metal pallet 10 is not limited to a flat pallet, and other shapes such as a box type can be used as long as it has an L-shaped frame 13.

1 is an overall view showing a data communication system of the present invention. The elements on larger scale which show the principal part of the metal pallets with an RFID tag of this invention. The side view which shows the metal corresponding | compatible RFID tag of this invention. Explanatory drawing which shows the effect | action of the metal corresponding | compatible RFID tag of this invention. The figure which shows an example which attached the conventional RFID tag to metal pallets.

Explanation of symbols

1 Data Communication System 2 Metal Pallet with RFID Tag 3 Reader / Writer (Communication Device)
DESCRIPTION OF SYMBOLS 10 Metal pallet 11 Base 12 Prop frame 13 L-shaped frame 14 Insert port 20 Metal-adaptive RFID tag 21 Spacer 22 Inlet sheet 23 Antenna 24 IC chip 25 Adhesive 30 Luggage

Claims (6)

  A metal-compatible RFID tag comprising a triangular prism-shaped spacer made of a non-conductive material, a conductive antenna provided on a slope of the spacer, and an IC chip connected to the antenna.   The metal-compatible RFID tag according to claim 1, wherein an inlet sheet on which an antenna and an IC chip are mounted is attached to a slope of the spacer.   3. The metal-compatible RFID tag according to claim 1, wherein a length from the apex of the spacer to the antenna is set in a range of 0.1 to 0.7λ.   4. A pedestal made of a metal material, mounted on a pedestal, an L-shaped frame supporting the pedestal, and attached to an inner wall surface of the L-shaped frame with the side surfaces of the spacer facing each other. A metal-made pallet with an RFID tag, comprising the metal-compatible RFID tag according to the item.   A communication pallet comprising: a metal pallet with an RFID tag according to claim 4; and a communication device for performing data communication between the metal-compatible RFID tag of the metal pallet with an RFID tag using an induction electromagnetic field or a radio wave. Data communication system.   5. An induction electromagnetic field or radio wave returned from a metal-compatible RFID tag in response to an induction electromagnetic field or radio wave radiated from a communication device is reflected on the L-shaped frame with respect to the metal pallet with an RFID tag according to claim 4. A data communication method comprising performing data communication.

Images