JP2010183379A - Wireless ic tag - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To extend a communication distance between IC tag and a reader/writer, and to prevent a communication distance between the tag and the reader/writer from being shortened, even if a metal object whose part has holes or the like is equipped with the tag, when the metal object is equipped with the wireless IC tag to carry out communications between the tag and the reader/writer. <P>SOLUTION: A first dielectric layer 12 is provided between a first communication antenna part 14 having an IC chip 13 and a second communication antenna part 11, a conductive layer 16 is provided on a surface of the first communication antenna 14 on a side opposite to the first dielectric layer 12 via a second dielectric layer 15, a notch 14a for impedance adjustment is provided in the first communication antenna part 14, and a notch 11a for frequency adjustment is provided in the second communication antenna part 11. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a wireless IC tag, and in particular, when a wireless IC tag is attached to a metal article and communication is performed between the wireless IC tag and a reader / writer, the communication with the reader / writer is performed. The feature is that the distance can be increased and the communication distance with the reader / writer can be prevented from being lowered even when it is attached to a metal article having holes or the like in part. It is what you have.

  In recent years, a wireless IC tag provided with a communication antenna and an IC chip is attached to an article for the purpose of managing the article or preventing theft of the article, and the wireless IC tag and reader / writer. RFID systems that communicate with each other have come to be used.

  In such a wireless IC tag, generally, when a radio wave of a predetermined frequency is transmitted from a reader / writer, operating power is generated from the radio wave received by the antenna to operate the IC chip. The stored information is rewritten, the information stored in the IC chip is read out, transmitted from the antenna, and read by the reader / writer.

  However, when the wireless IC tag as described above is attached to a metal article, when the wireless IC tag communicates with the reader / writer, radio waves received by the wireless IC tag are not received. As a result, communication between the wireless IC tag and the reader / writer may be performed due to the absorption of the metal object or interference with the reflected wave to prevent sufficient operating power from being obtained. There was a problem that the distance that could be shortened.

  In the past, when mounting the above wireless IC tag on a metal article, it was considered to increase the thickness of the spacer interposed between the wireless IC tag and the metal article. In such a case, there is a problem that the wireless IC tag becomes thick and obstructs.

  In recent years, as disclosed in Patent Document 1, a first antenna on which an IC chip is mounted and a first spacer for attaching the first antenna to a member via a required interval are provided. A wireless IC tag is proposed in which a second spacer is provided between the first antenna and a second antenna that resonates with a radio wave having a predetermined frequency.

  In the wireless IC tag disclosed in Patent Document 1, the second antenna has an auxiliary function for strengthening the radio wave transmitted from the first antenna, thereby increasing the communication distance at a predetermined frequency. I can do it.

  However, even in the wireless IC tag described in Patent Document 1, the distance that can be attached to a metal article and communicated with the reader / writer is still short, and information stored in the IC chip by the reader / writer is still A sufficient communication distance cannot be obtained for rewriting or reading information stored in an IC chip. To perform these operations, a reader / writer is used for wireless communication. There is a problem that it is necessary to guide the IC tag to a position close to the IC tag, and the work becomes very troublesome.

  Further, when the wireless IC tag described in Patent Document 1 is attached to a metal article having a hole, there is a problem that the distance that can be communicated with the reader / writer is greatly reduced.

Japanese Patent Laying-Open No. 2005-210676

  An object of the present invention is to solve the above-described problems in a wireless IC tag. A wireless IC tag is attached to a metal article, and the wireless IC tag and a reader / writer are connected to each other. When communicating with each other, the communication distance with the reader / writer can be increased, and the communication distance with the reader / writer can be increased even when it is attached to a metal article having a hole or the like in part. It is an object to be able to prevent the decrease.

  In the wireless IC tag of the present invention, a first dielectric layer is provided between the first communication antenna unit having the IC chip and the second communication antenna unit in order to solve the above-described problems. In addition, a conductive layer is provided via a second dielectric layer on the surface of the first communication antenna portion on the side opposite to the first dielectric layer, and an impedance adjustment cutout portion is provided in the first communication antenna portion. In addition, the second communication antenna unit is provided with a notch for frequency adjustment.

Here, in the above-described wireless IC tag, various conductive materials can be used as the material for the conductive layer, but a weak magnetic or diamagnetic so-called metal material such as aluminum, silver, or copper is used. It is preferable to use a nonmagnetic material. And, as such a material, the specific susceptibility preferably ¹⁰ -3 ^{to 10 -7} or ^-10 -3 ^{-10 -7} about materials.

  In addition, when the wireless IC tag is attached to a metal article made of a ferromagnetic material such as iron or nickel, the wireless IC tag can be easily attached to the metal article. In order to do so, the magnet part comprised with the magnet material can be provided under said conductive layer.

  In the wireless IC tag according to the present invention, the first communication antenna unit has a function as a matching circuit, and the first communication antenna unit is provided with a notch for adjusting impedance, while the first communication The second communication antenna portion provided via the antenna portion and the first dielectric layer is provided with a notch for adjusting the frequency, and the frequency adjustment and the impedance adjustment are performed between the second communication antenna portion and the first communication antenna portion. Since the antenna is separated from the communication antenna unit, the frequency and impedance of the wireless IC tag can be adjusted easily and appropriately.

  Then, by appropriately adjusting the frequency and impedance of the wireless IC tag as described above, the wireless IC tag is attached to a metal article and communicated with the reader / writer. In this case, it is considered that the communication distance between the reader / writer is greatly increased.

  In addition, in the wireless IC tag according to the present invention, as described above, the conductive layer is provided on the surface of the first communication antenna portion on the opposite side to the first dielectric layer via the second dielectric layer, and therefore a part thereof Even when the wireless IC tag is attached to a metal article having a hole or the like in the metal plate, the effect of the hole or the like provided in the metal article is suppressed by the conductive layer. Thus, it is possible to suppress a reduction in communication distance when performing communication.

  As a result, in the wireless IC tag according to the present invention, the distance that can be communicated with the reader / writer is greatly increased when the wireless IC tag is attached to a metal article and communicates with the reader / writer. Even when it is attached to a metal article having a hole or the like in part, it is possible to prevent the distance that can be communicated with the reader / writer from decreasing.

1 is an exploded perspective view of a wireless IC tag according to an embodiment of the present invention. It is a schematic plan view of the wireless IC tag according to the embodiment. It is the schematic explanatory drawing which showed the laminated structure of the radio | wireless IC tag which concerns on said embodiment. It is the schematic plan view which showed the state which mounted | wore the plate-shaped metal article | item with the radio | wireless IC tag which concerns on said embodiment. It is the schematic plan view which showed the state mounted | worn with the radio | wireless IC tag which concerns on said embodiment so that it might overlap with the hole of columnar metal articles | goods in which a hole exists. In the wireless IC tag according to the above embodiment, it is a schematic explanatory view showing a state in which a magnet portion is provided under a conductive layer.

  Next, a wireless IC tag according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings. The wireless IC tag according to the present invention is not particularly limited to those shown in the following embodiments, and can be implemented with appropriate modifications within a range not changing the gist thereof.

  As shown in FIG. 1, the wireless IC tag 10 in this embodiment includes a second communication antenna unit 11 made of a metal sheet such as an aluminum foil, and a first dielectric made of an insulating sheet such as polypropylene. Body layer 12, IC chip 13, first communication antenna portion 14 made of a metal sheet such as aluminum foil, second dielectric layer 15 made of an insulating sheet such as foamed polyethylene terephthalate, and aluminum It is comprised with the conductive layer 16 comprised with metal sheets, such as foil.

  The second communication antenna unit 11 is provided with a frequency adjusting cut portion 11a.

  Further, the first communication antenna section 14 is provided with a notch section 14a for impedance adjustment, and a pair of mounting sections extending so as to face each other at a necessary interval in the notch section 14a. The IC chip 13 is attached so as to span between 14b and 14b, and the impedance between the first communication antenna unit 14 and the IC chip 13 is matched.

  In the wireless IC tag 10 according to this embodiment, as shown in FIGS. 3 and 4, the impedance adjustment cut portion 14 a in the first communication antenna unit 14 to which the IC chip 13 is attached is provided in the second communication. The first dielectric layer 12 is placed between the first communication antenna unit 14 and the second communication antenna unit 11 so as to be positioned in the frequency adjustment cutout portion 11 a provided in the antenna unit 11. The first communication antenna unit 14 and the second communication antenna unit 11 are electrically separated from each other by the first dielectric layer 12 so as to be sandwiched therebetween.

  Further, a conductive layer 16 is laminated on the surface of the first communication antenna section 14 opposite to the first dielectric layer 12 with the second dielectric layer 15 interposed therebetween, and this second dielectric layer. 15, the first communication antenna unit 14 and the conductive layer 16 are electrically separated.

  And between the 2nd communication antenna part 11, the 1st dielectric material layer 12, the 1st communication antenna part 14, the 2nd dielectric material layer 15, and the conductive layer 16 which were laminated in this way, respectively. The wireless IC tag of this embodiment is obtained by bonding with an adhesive (not shown).

  Here, in the wireless IC tag 10 of this embodiment, the shape and size of the frequency adjustment cut-out portion 11 a provided in the second communication antenna unit 11 and the impedance adjustment provided in the first communication antenna unit 14. The shape and size of the cut portion 14a for use are appropriately changed in accordance with the frequency at the time of communication with the reader / writer (not shown), the impedance of the IC chip 13, and the like.

  Further, in the wireless IC tag of this embodiment, the notch portion 14a for impedance adjustment in the first communication antenna portion 14 to which the IC chip 13 is attached is used for frequency adjustment provided in the second communication antenna portion 11. Although it was made to locate in the notch part 11a, the notch part 14a for impedance adjustment of the antenna part 14 for 1st communication may be in the state covered with the antenna part 11 for 2nd communication. In short, the wireless IC tag 10 is connected to the reader / writer by the frequency adjusting cut portion 11a in the second communication antenna portion 11 and the impedance adjustment cut portion 14a in the first communication antenna portion 14. It is only necessary to be able to adapt to the frequency at the time of communication between the two and the impedance of the IC chip 13.

  Then, as shown in FIG. 4, the wireless IC tag 10 is connected to the metal article 1 described above so that the conductive layer 16 of the wireless IC tag 10 is in contact with the plate-like metal article 1. When the communication is performed with the reader / writer in the state of being attached to the reader / writer, since the adjustment of the frequency and the impedance in the wireless IC tag 10 is appropriately performed as described above, the reader / writer The distance that can be communicated with is greatly increased.

  In addition, as shown in FIG. 5, the wireless IC tag 10 is connected to the hole 1a of the columnar metal article 1 in which the hole 1a is present so that the conductive layer 16 of the wireless IC tag 10 has the above-described structure. Even when the metal article 1 is mounted, the conductive layer 16 suppresses the influence of the hole 1a provided in the metal article 1, and when communicating with the reader / writer. A reduction in communication distance is prevented.

  When the wireless IC tag 10 is attached to a metal article 1 made of a ferromagnetic material such as iron or stainless steel, it can be attached by sticking with an adhesive or the like. 6, a magnet portion 17 made of a magnetic material is provided under the conductive layer 16, and the wireless IC tag 10 is magnetically attached to the metal article 1 by the magnet portion 17. You can also Even when the magnet portion 17 made of a magnet material is provided under the conductive layer 16 as described above, if the conductive layer 16 is made of a nonmagnetic conductive material such as aluminum, silver, or copper, The communication distance when communicating with the reader / writer is not reduced.

  Next, in the wireless IC tag according to the present invention, both the case where it is attached to a metal article and the case where it is attached to a metal article having a hole are sufficient between the reader / writer. The fact that the communication distance can be obtained will be described with reference to examples and comparative examples.

  Here, in the wireless IC tag of the example, in the wireless IC tag 10 in the above embodiment, an aluminum foil having a thickness of 16 μm is formed on the first dielectric layer 12 in the second communication antenna unit 11. A polypropylene film having a thickness of 100 μm, an aluminum foil having a thickness of 16 μm for the first communication antenna portion 14, a foamed polyethylene terephthalate sheet having a thickness of 590 μm for the second dielectric layer 15, and an aluminum having a thickness of 16 μm for the conductive layer 16. A foil was used.

  On the other hand, in the wireless IC tag of the comparative example, the conductive layer 16 in the wireless IC tag of the above example was not provided.

  In Experiment 1, each of the wireless IC tags of the example and the comparative example is attached to a metal article made of a stainless steel plate as shown in FIG. 4, and in Experiment 2, the examples and comparative examples are mounted. As shown in FIG. 5, each wireless IC tag is mounted so as to include a hole portion in a metal article made of a perforated steel column, and each reader / writer (manufactured by Mitsubishi Electric Corporation: RF-RW001) is attached. ), The distance that can be communicated with each wireless IC tag was measured under the conditions of an output of 1 W and a frequency of 952 to 954 MHz. The results are shown in Table 1 below.

この結果、ステンレス板に装着させた実験１の場合、実施例の無線用ＩＣタグは、その通信距離が、比較例の無線用ＩＣタグの通信距離よりもある程度増加していた。

As a result, in Experiment 1 attached to a stainless steel plate, the communication distance of the wireless IC tag of the example was increased to some extent than the communication distance of the wireless IC tag of the comparative example.

  In the case of Experiment 2 attached to a perforated steel pillar, the communication distance of the wireless IC tag of the comparative example was greatly reduced compared to the case of Experiment 1 attached to a stainless steel plate. On the other hand, in the wireless IC tag of the embodiment, the communication distance is almost the same as in Experiment 1 in which the stainless steel plate is mounted, and the communication distance is significantly increased compared to the wireless IC tag of the comparative example. It was.

DESCRIPTION OF SYMBOLS 1 Metal article 1a Hole 10 Wireless IC tag 11 2nd communication antenna part 11a Frequency adjustment cut-in part 12 1st dielectric layer 13 IC chip 14 1st communication antenna part 14a Impedance adjustment cut-out part 14b Mounting portion 15 Second dielectric layer 16 Conductive layer 17 Magnet portion

Claims (3)

  A first dielectric layer is provided between the first communication antenna unit including the IC chip and the second communication antenna unit, and the first communication antenna unit on the side opposite to the first dielectric layer is provided. A conductive layer is provided on the surface via a second dielectric layer, an impedance adjustment cutout is provided in the first communication antenna section, and a frequency adjustment cutout is provided in the second communication antenna section. A wireless IC tag characterized in that a portion is provided.   2. The wireless IC tag according to claim 1, wherein the conductive layer is made of a nonmagnetic material.   The wireless IC tag according to claim 1 or 2, wherein a magnet portion made of a magnet material is provided under the conductive layer.

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