JP2022029374A - How to place RF-tagged articles and RF-tagged articles - Google Patents

Abstract

[Problem] To prevent RF tag communication from being impeded even when an article with an RF tag attached is placed on a metal fixture. [Solution] RF tagged article 1 is an article 3 to which an RF tag 2 is attached. The RF tag 2 has an IC chip 24 and an antenna 20 connected thereto. The antenna 20 has an antenna matching circuit 23 connected to the IC chip 24, and a first antenna element 21 and a second antenna element 22 connected to the antenna matching circuit 23, respectively, and at least the first antenna element 21 is planar. In the RF tagged article 1, the RF tag 2 is folded between the first antenna element 21 and the antenna matching circuit 23, and is attached to the article 3 such that the second antenna element 22 and the antenna matching circuit 23 are disposed on the side surface 3b of the article 3, and the first antenna element 21 is disposed on the bottom surface 3a of the article 3. [Selected Figure] Figure 1

Description

The present invention relates to an article and a metal fixture to which an RF (Radio-Frequency) tag is attached.

In automatic recognition technology using short-range wireless communication, information media attached to articles and people are called RF tags. The RF tag may also be referred to as a wireless tag, an IC tag, an RFID tag, or the like.

RF tags use radio waves (electromagnetic waves) for short-range wireless communication with reader / writers. Therefore, when the RF tag is attached to the metal surface, the communication of the RF tag is hindered by the reflected wave from the metal surface. Therefore, when attaching the RF tag to the metal surface, it is necessary to make the RF tag correspond to the metal surface.

Techniques for making RF tags correspond to metal surfaces have already been disclosed in various patent documents and the like. As a technique for making an RF tag correspond to a metal surface, a technique for providing a magnetic material having a high magnetic permeability (for example, ferrite) on the back surface of the RF tag is disclosed in Patent Document 1 and the like. On the other hand, as a technique for making an RF tag correspond to a metal surface, a technique for utilizing the metal surface of an article as a part of an antenna is also disclosed in Patent Document 2 and the like.

Japanese Unexamined Patent Publication No. 2006-301900 Re-table 2019/116758 Gazette

However, even if the surface of the article to which the RF tag is attached is not a metal surface, when the article to which the RF tag is attached is placed on a metal fixture (for example, a metal product shelf), the RF tag is affected by the metal fixture. ， RF tag communication is hindered.

Therefore, it is an object of the present invention to prevent the communication of the RF tag from being disturbed even if the article to which the RF tag is attached is placed on the metal fixture.

The first invention for solving the above-mentioned problems includes an IC chip and an antenna connected to the IC chip, and the antenna includes an antenna matching circuit connected to the IC chip and a first antenna element connected to the antenna matching circuit, respectively. An RF tag having a second antenna element and having at least the first antenna element in a planar shape is folded between the first antenna element and the antenna matching circuit, and the second antenna element and the antenna matching circuit are folded. Is an RF-tagged article characterized in that the first antenna element is arranged on the side surface of the article and attached to the article so that the first antenna element is arranged on the bottom surface of the article.

The second invention for solving the above-mentioned problems is a method of mounting the RF-tagged article described in the first invention on a metal fixture, in which the bottom surface of the RF-tagged article and the mounting surface of the metal fixture face each other. The RF-tagged article is placed on the metal fixture, and the RF-tagged antenna attached to the RF-tagged article has a planar shape arranged on the bottom surface of the RF-tagged article. It is a method for placing an article with an RF tag, which comprises capacitively coupling the first antenna element and the metal fixture.

The article with an RF tag according to the present invention is a surface arranged on the bottom surface of the article with an RF tag so that the communication of the RF tag is not obstructed even if the article with the RF tag is placed on a metal fixture. The first antenna element in the shape and the metal fixture are configured to be capacitively coupled.

The perspective view of the article with an RF tag which concerns on this embodiment. The figure explaining the RF tag. The figure explaining the inlay. The figure explaining how to attach an RF tag. The figure explaining the placement method of the article with an RF tag. The figure explaining the state which capacitively coupled with the planar first antenna element and the mounting surface of a metal fixture.

Hereinafter, the method of placing the RF-tagged article 1 according to the present invention and the RF-tagged article 1 according to the present invention will be described with reference to the drawings. It should be noted that the technical scope of the present invention is not limited to the contents of the embodiments described below, but extends to the inventions described in the claims and their equivalents.

FIG. 1 is a perspective view of an article 1 with an RF tag according to the present embodiment. The article 1 with an RF tag according to the present embodiment is an article 3 to which the RF tag 2 is attached. The RF tag 2 includes an IC chip 24 and an antenna 20 connected to the IC chip 24. The antenna 20 has an antenna matching circuit 23 connected to the IC chip 24, a first antenna element 21 and a second antenna element 22 connected to the antenna matching circuit 23, respectively, and at least the first antenna element 21 is planar. ing. In the article 1 with an RF tag, the RF tag 2 is folded between the first antenna element 21 and the antenna matching circuit 23, and the second antenna element 22 and the antenna matching circuit 23 are placed on the side surface 3b of the article 3 and the first antenna element. 21 is attached to the article 3 so as to be arranged on the bottom surface 3a of the article 3, respectively.

FIG. 2 is a diagram illustrating the RF tag 2. FIG. 2A is a surface view of the RF tag 2, and FIG. 2B is a diagram illustrating a layer structure of the RF tag 2.

As shown in FIG. 2A, the RF tag 2 attached to the article 3 is in the form of a sticker label, and its shape is substantially rectangular. The RF tag 2 is processed with a folding line 25 as a mark of a portion where the RF tag 2 is folded between the first antenna element 21 and the antenna matching circuit 23. The fold line 25 may be simply printed, but may be a perforation or a streak line if the antenna 20 is not cut.

As shown in FIG. 2B, the layer structure of the RF tag 2 includes a surface sheet 200 which is the surface of the RF tag 2, a first adhesive layer 201 formed by using an adhesive or the like, and an IC chip 24. The structure is such that an inlay 202 in which an antenna 20 connected to the antenna 20 is mounted on a base sheet 202a and a second adhesive layer 203 formed by using an adhesive or the like are laminated. The layer structure of the RF tag 2 shown in FIG. 2 is only an example, and the layer structure of the RF tag 2 attached to the article 3 is arbitrary.

On the surface sheet 200 that is the surface of the RF tag 2, a pattern for giving the RF tag 2 decorativeness can be printed. A plastic material that functions as a dielectric is used for the surface sheet 200. As the plastic material that functions as a dielectric, for example, polyethylene terephthalate can be used.

The first adhesive layer 201 is a layer for bonding the surface of the inlay 202 on which the antenna 20 and the like are mounted and the surface sheet 200. For the first pressure-sensitive adhesive layer 201, for example, known adhesives and pressure-sensitive adhesives such as rubber-based, EVA-based, olefin-based, polyester-based, polyamide-based, and urethane-based can be used.

The second adhesive layer 203 is a layer for bonding the surface of the inlay 202 on which the antenna 20 or the like is not mounted and the article 3. For the second pressure-sensitive adhesive layer 203, for example, known pressure-sensitive adhesives such as rubber-based, EVA-based, olefin-based, polyester-based, polyamide-based, and urethane-based can be used.

FIG. 3 is a diagram illustrating the inlay 202. The frequency band used by the RF tag 2 attached to the surface of the article 3 for short-range wireless communication is the UHF band (860 to 960 Mhz). The antenna 20 mounted on the inlay 202 is a UHF band antenna (for example, a half-wavelength dipole antenna). As described above, in the present embodiment, the antenna 20 mounted on the inlay 202 has the first antenna element 21 and the second antenna element 22 connected to both sides of the loop-shaped antenna matching circuit 23 to which the IC chip 24 is connected. It has a structure that makes it.

Various plastic materials such as polyethylene terephthalate can be used as the base material of the inlay 202 on which the antenna 20 and the like are mounted. The antenna 20 is formed by using a metal foil such as a copper foil or an aluminum foil.

The antenna matching circuit 23 of the antenna 20 mounted on the inlay 202 serves as an antenna element for impedance matching with the IC chip 24. The shape of the antenna matching circuit 23 connected to the IC chip 24 is loop-shaped in order to match the capacitance existing between the input terminals of the IC chip 24.

The first antenna element 21 and the second antenna element 22 included in the antenna 20 are antenna elements used for communication with an external reader / writer. The first antenna element 21 and the second antenna element 22 are arranged so as to oppose each other with the antenna matching circuit 23 interposed therebetween.

The first antenna element 21 included in the antenna 20 is an antenna element that is capacitively coupled to the mounting surface 4a of the metal fixture 4 on which the article 1 with the RF tag is mounted. The first antenna element 21 of the antenna 20 has a planar shape so that it can be capacitively coupled to the mounting surface 4a of the metal fixture 4, and the area of the first antenna element 21 is the same as the mounting surface 4a of the metal fixture 4. The size is such that the electrostatic capacity of the antenna can be sufficiently taken.

The second antenna element 22 included in the antenna 20 is an antenna element that is not capacitively coupled to the mounting surface 4a of the metal fixture 4. Therefore, the shape of the second antenna element 22 is arbitrary. In FIG. 3, the second antenna element 22 has the same shape as the first antenna element 21, but the second antenna element 22 may be linear (for example, a meander shape).

FIG. 4 is a diagram illustrating how to attach the RF tag 2. The fold line 25 processed into the RF tag 2 is aligned with one side of the bottom surface 3a of the article 3, and the RF tag in which the first antenna element 21 is arranged is arranged by using the second adhesive layer 203 formed on the back surface of the RF tag 2. Part 2 is attached to the bottom surface 3a of the article 3. Next, using the second adhesive layer 203 formed on the back surface of the RF tag 2, the remaining portion of the RF tag 2 in which the second antenna element 22 and the antenna matching circuit 23 are arranged is placed on the side surface 3b of the article 3. The RF tag 2 is attached to the article 3.

FIG. 5 is a diagram illustrating a method of placing the article 1 with an RF tag. The method of mounting the article 1 with an RF tag is a method of mounting the article 1 with an RF tag described above on the metal fixture 4, and the first antenna element 21 of the RF tag 2 and the mounting surface 4a of the metal fixture 4 are mounted. In order to perform capacitive coupling, the RF-tagged article 1 is placed on the metal fixture 4 with the bottom surface 3a of the RF-tagged article 1 and the mounting surface 4a of the metal fixture 4 facing each other. The number of RF-tagged articles 1 placed on one metal fixture 4 does not have to be one, and a plurality of RF-tagged articles 1 may be placed on one metal fixture 4. Further, in order to capacitively couple the first antenna element 21 of the RF tag 2 and the mounting surface 4a of the metal fixture 4, the sheet resistance of the mounting surface 4a of the metal fixture 4 is preferably 100Ω / sq or less. ..

FIG. 6 is a diagram illustrating a state in which the planar first antenna element 21 and the mounting surface 4a of the metal fixture 4 are capacitively coupled. By placing the RF-tagged article 1 on the metal fixture 4 with the bottom surface 3a of the RF-tagged article 1 and the mounting surface 4a of the metal fixture 4 facing each other, the first antenna element 21 of the RF tag 2 and the metal The first pressure-sensitive adhesive layer 201 of the RF tag 2 and the surface sheet 200 are present between the mounting surface 4a of the fixture 4. The first antenna element 21 of the RF tag 2 and the mounting surface 4a of the metal fixture 4 can be regarded as a pair of metal plates, and a dielectric such as the surface sheet 200 is sandwiched between the pair of metal plates. The space between the first antenna element 21 of the RF tag 2 and the mounting surface 4a of the metal fixture 4 functions as a capacitor. If the space between the first antenna element 21 of the RF tag 2 and the mounting surface 4a of the metal fixture 4 functions as a capacitor, a high frequency current will flow through the mounting surface 4a of the metal fixture 4, and the metal fixture 4 will be the RF tag. It functions as an antenna element of 2 and the communication of RF tag 2 is not disturbed.

1 Article with RF tag 2 RF tag 20 Antenna 21 1st antenna element 22 2nd antenna element 23 Antenna matching circuit 24 IC chip 3 Article 3a Bottom 3b Side surface 4 Metal fixture 4a Mounting surface

Claims (2)

The antenna includes an IC chip and an antenna connected to the IC chip, and the antenna has an antenna matching circuit connected to the IC chip, and a first antenna element and a second antenna element connected to the antenna matching circuit, respectively, and at least the first antenna element. The RF tag having one antenna element in a planar shape is folded between the first antenna element and the antenna matching circuit, and the second antenna element and the antenna matching circuit are arranged on the side surface of the article. An article with an RF tag, characterized in that the antenna element is attached to the article so as to be arranged on the bottom surface of the article. The method for mounting the RF-tagged article according to claim 1 on a metal fixture, wherein the RF-tagged article is placed on the metal fixture with the bottom surface of the RF-tagged article and the mounting surface of the metal fixture facing each other. The metal fixture is capacitively coupled to the planar first antenna element placed on the metal fixture and attached to the RF-tagged article by the RF-tagged antenna and arranged on the bottom surface of the RF-tagged article. A method of placing an article with an RF tag, which is characterized in that the article is placed.

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