JP2013079123A - Conveying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To highly accurately read an RFID tag attached to an article to be conveyed, in a conveying device for conveying a package to which the RFID tag is attached.SOLUTION: The conveying device 1 includes an article conveying part 5 provided to the front surface of the conveying device 1 and an operation part 10 for operating motion of the article conveying part 5. An antenna 20 for reader/writer for reading and writing the RFID tag is provided to the article conveying part 5. Further, a net-like metallic member 25 whose area is larger than that of the antenna 20 is provided to the rear surface of the antenna for reader/writer 20.

Description

  The present invention relates to a transport device, and more particularly to a transport device for transporting an article such as a forklift.

  In recent years, an RFID system using a reader / writer and an RFID (Radio Frequency Identification) tag is spreading. The RFID tag has ID information that can be identified for each tag. By reading and writing the RFID tag attached to the article with a reader / writer, the ID information of each article can be obtained by wireless communication. it can.

  This RFID system is expected to be used as an article management system in factories and warehouses. Specifically, for example, as disclosed in Patent Document 1 and Patent Document 2, an RFID tag is attached to a load or a pallet for transportation, and the information is read and written by a reader / writer provided in the forklift. A system has been proposed. Since this system can identify and collect information on the transportation destination of goods, inventory information, and the like via wireless communication, it can efficiently perform article management and physical distribution management in factories and warehouses.

  However, since there are a lot of other packages in the factory and warehouse as well as the packages to be transported, when the packages are separated from the reader / writer antenna, they are attached to other packages that are not transported. RFID tags may also be read. On the other hand, if the baggage and the reader / writer antenna are close, the possibility of reading an RFID tag attached to another baggage that is not transported is reduced, but the directivity of the antenna is limited. Therefore, it is difficult to reliably read RFID tags arranged in a wide range.

JP 2002-321899 A JP 2006-347713 A

  An object of the present invention is to provide a transport apparatus that can accurately read an RFID tag attached to an article to be transported such as a luggage or a transport pallet.

A transport apparatus according to an aspect of the present invention is
A transport device for transporting an article to be transported with an RFID tag,
Provided on the front surface of the transport apparatus, and has an article transport section for transporting the article to be transported, and an operation section for controlling operations of the transport apparatus and the article transport section,
A reader / writer antenna for reading and writing the RFID tag is provided in the transport device so that a radiation surface faces the article to be transported,
A net-like metal member having a larger area than the reader / writer antenna is disposed on the back side of the reader / writer antenna.
It is characterized by that.

  According to the present invention, since the net-like metal member having a larger area than the reader / writer antenna is disposed on the back side of the reader / writer antenna, the article to be transported does not greatly impair the operability of the transport device. The RFID tag attached to can be read with high accuracy.

1 is a schematic external view of a forklift and luggage according to an embodiment. It is an external appearance enlarged view of the net-like metal member (metal mesh) and the antenna part for reader / writers. It is a side view for demonstrating the positional relationship of the said forklift and a load. It is the elements on larger scale for demonstrating the reading principle of the tag by the antenna for reader / writers. It is the elements on larger scale of the said metal mesh. It is a general | schematic external view which shows the other example of the said mesh-like metal member (metal mesh).

  Hereinafter, embodiments of a transfer device according to the present invention will be described with reference to the accompanying drawings.

  The transport apparatus shown in FIG. 1 is a forklift 1, which includes a fork unit 5 that functions as an article transport unit for transporting articles to be transported (packages) 50 loaded on a transport pallet 40, and the forklift 1 and fork. A driver's seat 10 that functions as an operation unit for controlling the operation of the unit 5 is provided. An RFID system in the UHF band is used as the RFID system.

  The fork unit 5 can move up and down and is provided on the front surface of the forklift 1. Although not shown, the driver's seat 10 is provided with a lift lever for operating the fork unit 5, a handle for operating the main body of the forklift 1, a brake pedal, an accelerator pedal, and the like. The basic configuration of the forklift 1 is the same as that of a well-known forklift.

  As shown in FIG. 3, a UHF band RFID tag 51 is attached to one main surface side of each load 50 mounted on the transfer pallet 40. The RFID tag 51 includes an RFID IC chip having a memory circuit, a logic circuit, and the like, and an antenna element connected to the IC chip. A dipole antenna is used as the antenna element. The packages 50 are arranged on the pallet 40 so that the antenna elements of the RFID tags 51 attached to the packages 50 face the reader / writer antenna 20.

  As shown in FIGS. 1 and 3, the reader / writer antenna 20 for reading and writing the RFID tag 51 is provided on the front surface of the forklift 1 so that the radiation surface 20 a faces the mounting surface of the RFID tag 51 of the luggage 50. It has been. More specifically, the forklift 1 is attached to the surface of the fork portion 5 facing the load 50. The reader / writer antenna 20 is a patch antenna, and an information processing circuit for processing information read by the antenna element, a display device for displaying this information, and the like are connected to the reader / writer antenna 20. ing. These information processing circuit and display device may be housed in the same housing as the reader / writer antenna 20 or may be provided in a housing different from the housing of the reader / writer antenna 20.

  As shown in FIGS. 1, 2, and 3, a net-like metal member 25 is disposed on the back side of the reader / writer antenna 20 (on the side opposite to the radiation surface 20 a of the reader / writer antenna 20). The mesh metal member 25 is a metal mesh. The wire mesh 25 is provided on the fork portion 5 of the forklift 1 and is attached to the fork portion 5 so that the main surface thereof faces the surface of the luggage 50 to which the RFID tag 51 is attached. When the reader / writer antenna 20 and the wire mesh 25 are both provided in the fork portion 5 which is a movable portion in this way, the relative position between the reader / writer antenna 20 and the wire mesh 25 does not change. The wire mesh 25 has a larger area than the reader / writer antenna 20. That is, as shown in FIG. 5, the wire mesh 25 is made by braiding linear metal materials 25a and 25b, and has a plurality of openings 25c arranged in a grid. The area of the wire mesh 25 is preferably substantially equal to the area of the surface (opposed surface) of the luggage 50 to which the tag 51 is attached. If the area of the wire mesh 25 is too smaller than the area of the facing surface of the luggage 50, it will be difficult to read all of the plurality of RFID tags 51 properly. If it is too large, the RFID tag attached to the other luggage not being conveyed. May be read.

  In this forklift 1, in particular, between the reader / writer antenna 20 attached to the front surface of the forklift 1 and the driver's seat 10 for operating the forklift 1 and the fork unit 5, the rear surface of the reader / writer antenna 20 is provided. Since a net-like metal member (metal mesh) 25 having an area larger than that of the reader / writer is arranged on the side, even when the reader / writer antenna 20 is brought close to the RFID tag 51, it is attached to a plurality of packages 50. Further, each ID information of the plurality of RFID tags 51 can be read with high accuracy.

  More specifically, when the load 50 and the forklift 1 are separated from each other, the RFID tag attached to another load that is not transported may be read, so the tag 51 by the reader / writer antenna 20 is read. Is started when the fork unit 5 is inserted into the pallet 40 or when the fork unit 5 is inserted into the pallet 40. At this time, the distance between the reader / writer antenna 20 and the RFID tag 51 is short. Therefore, as shown in FIG. 4, the electromagnetic wave A directly reaching the RFID tag 51 among the electromagnetic waves radiated from the reader / writer antenna 20 can be picked up properly by the RFID tag 51. That is, the electromagnetic wave A contributes to the communication between the reader / writer and the RFID tag 51 regardless of the presence or absence of the wire mesh 25.

  On the other hand, when there is no wire mesh 25, the electromagnetic waves that did not reach the RFID tag 51 are partially reflected by the luggage 50 or the pallet 40, and the reflected electromagnetic waves are used for communication between the reader / writer and the RFID tag 51. Does not contribute. However, when the wire mesh 25 is arranged as in the present embodiment, the electromagnetic wave reflected by the luggage 50 and the pallet 40 is further reflected by the wire mesh 25 as shown by the electromagnetic wave B in FIG. Reaches the RFID tag 51, and the amount of electromagnetic waves contributing to communication with the RFID tag 51 increases. As a result, the ID information of the plurality of RFID tags 51 attached to the plurality of packages 50 can be read. Further, as shown in FIG. 5, since the wire mesh 25 has the opening 25 c, the visibility from the driver's seat 10 is not greatly deteriorated, and the operability of the forklift 1 by the driver and the fork part 5 The operability is hardly impaired.

  In this embodiment, the luggage 50 may be a case such as a cardboard box, but it is preferable that at least the surface to which the RFID tag 51 is attached is a metal surface case. The exterior of the case may be all metal. The case itself may be a metal case, or may be a metalized surface of a resin case. A metal powder mixed in a resin and molded may be used. If at least the surface to which the RFID tag 51 is attached is a metal, the electromagnetic wave radiated from the reader / writer antenna 20 is reflected by the metal surface of the case. Therefore, the amount of electromagnetic wave that does not contribute to communication with the RFID tag 51 is reduced. Can be reduced.

  Moreover, it is preferable that the opening diameter of the opening part 25a of the metal mesh 25 is λ / 4 or less of the carrier frequency. That is, in the case of a UHF band RFID system, it is preferable to set the opening diameter of the opening 25a to about 2.5 to 25 cm. If the opening diameter is in such a range, the wire mesh 25 can sufficiently function as a reflector. Note that the shape of the opening 25a is not limited to a square, and the lateral length (X) and the longitudinal length (Y) may be different. Moreover, you may have arbitrary shapes, such as circular and an ellipse.

  The wire mesh 25 is not limited to a flat wire mesh, and as shown in FIG. 6, a main surface portion 26 a provided in the back surface direction of the reader / writer and four sides provided in the side surface direction of the reader / writer 20. It may be a lid-shaped wire mesh having a portion (first side portion to fourth side portion 26b to 26e). Of the four side portions, for example, the shape may be such that the fourth side portion 26e is not provided, and it is not necessary to provide a wire mesh on all the side portions. Moreover, a hook-shaped (parabolic) wire mesh may be used.

  In addition, the conveying apparatus which concerns on this invention is not limited to the said Example, It can deform | transform variously within the range of the summary.

  For example, the RFID system to be used is not limited to the UHF band RFID system. For example, RFID systems in various frequency bands such as an HF band RFID system can be used.

  The article to be transported may be a pallet for mounting it as well as a luggage such as a case. That is, the RFID tag may be attached to the pallet as well as the luggage. It may be attached only to the pallet. The article to be transported may be accommodated in a case. In this case, the case is used only for conveyance.

  The reader / writer and the wire mesh are not limited to the configuration provided in the fork portion of the forklift. For example, the wire mesh is provided in the backrest portion or the lift body portion of the forklift, and the reader / writer is provided in the fork portion. Such a configuration may be adopted, and both the wire mesh and the reader / writer may be provided in the backrest portion or the lift main body portion.

  In addition to the dipole antenna, various antennas such as a loop antenna, an inverted F antenna, and a patch antenna can be used as the antenna of the RFID tag. Similarly, various antennas such as a dipole antenna, a loop antenna, and an inverted F antenna can be used for the reader / writer antenna in addition to the patch antenna.

  Further, the transport device is not limited to a forklift, and may be, for example, a hand cart or a car for transporting luggage.

  Moreover, although a metal mesh was used as the mesh metal member, this member is not limited to a metal mesh formed by weaving a linear metal, for example, a plurality of openings are provided in an insulating flat base material, Of the surface of the flat substrate, a metallized attachment surface of the reader / writer antenna may be used.

  The present invention is useful for a transport device such as a forklift, and is particularly excellent in that it can be used for information management of articles to be transported in a warehouse or factory.

DESCRIPTION OF SYMBOLS 1 ... Forklift 5 ... Fork part 10 ... Driver's seat 20 ... Reader / writer antenna 25 ... Wire mesh 50 ... Luggage 51 ... RFID tag

Claims (6)

A transport device for transporting an article to be transported with an RFID tag,
Provided on the front surface of the transport apparatus, and has an article transport section for transporting the article to be transported, and an operation section for controlling operations of the transport apparatus and the article transport section,
A reader / writer antenna for reading and writing the RFID tag is provided in the transport device so that a radiation surface faces the article to be transported,
A net-like metal member having a larger area than the reader / writer antenna is disposed on the back side of the reader / writer antenna.
A conveying apparatus characterized by that.   The transport apparatus according to claim 1, wherein the article to be transported is a case where at least a surface to which the RFID tag is attached is a metal surface, or is accommodated in the case.   The transport apparatus according to claim 1, wherein the reader / writer antenna and the mesh metal member are provided in the article transport section of the transport apparatus.   The conveying apparatus according to any one of claims 1 to 3, wherein an opening diameter of the opening in the net-like metal member is λ / 4 or less of a carrier frequency.   The net-like metal member has a main surface portion provided on a back surface side of the reader / writer antenna and a side surface portion provided on a side surface side of the reader / writer antenna. Item 5. The transport device according to any one of Items 4 to 5.   The transport apparatus according to any one of claims 1 to 5, wherein the transport apparatus is configured as a forklift having a fork section as the article transport section and a driver's seat as the operation section.

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