JP2004140513A - Antenna for reader / writer and article control shelf provided with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna for reader / writer and an article control shelf with a simple configuration without the need for using many conductor materials capable of easily extending an influencing range of a magnetic field generated from a loop antenna on an IC card within a prescribed range or easily extending the prescribed range wherein the magnetic field generated from the IC card can be detected thereby to be surely capable of performing communication even when the position of the IC card with respect to the loop antenna is more ore less deviated and controlling articles with excellent reliability. <P>SOLUTION: In the antenna 2A for the reader / writer configured to arrange conductors in a way of interlinking with the magnetic field and for performing radio communication with the IC card, at least parts of the cross section of the conductors are shaped to be extended to a range of detecting the magnetic field. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a reader / writer antenna for performing wireless communication with an IC card attached to an article, and an article management shelf in which the reader / writer antenna is incorporated in a shelf for storing articles.
[0002]
[Prior art]
An article management system that manages articles by wireless communication using an IC card and a reader / writer can send and receive information about articles between the IC card and the reader / writer in a non-contact manner. Since the management of the location of articles can be performed very easily, it has recently been applied to various article management.
[0003]
The applicant has already applied such an article management system to libraries, etc., and in addition to the conventional lending business, obtains book position information in real time, grasps the lending status, and grasps the location of the book. Has proposed an article management system capable of managing books (for example, see Patent Document 1).
[0004]
FIG. 6 is a perspective view showing one article management shelf.
On the article management shelf 10A, three shelves are configured by shelves 1a, 1b, and 1c provided in a plurality of stages (three stages in the figure) in parallel in the vertical direction.
In each of the shelves 1a, 1b, 1c, a loop line forming a one-loop antenna 2A is embedded in the plane of the shelf 1a, and a loop line forming a tool loop antenna 2B is embedded in the plane of the shelf 1b. A loop line forming the four-loop antenna 2C is embedded in the plane of the shelf 1c.
[0005]
The one-loop antenna 2A has a rectangular shape along the outer shape of the shelf 1a, and the tool loop antenna 2B has a figure-eight shape having a shape folded at almost half the position of the shape of the shelf 1b. The antenna 2C has a shape that is folded at three positions of the shelf 1c, which are substantially divided into four.
The loop antennas 2A, 2B, and 2C are connected to a tuning circuit described later, and the tuning circuit is connected to the reader / writer 6 via the coaxial cable 20.
[0006]
FIG. 7 shows an example of the tuning circuit 3. The tuning circuit 3 is formed on a substrate by a transformer 3a and a capacitor 3b. The tuning circuit 3 resonates with the loop line 2a to achieve impedance matching, and is connected to the coaxial cable 20. The coaxial cable 20 is connected to the reader / writer 6 via a connector 20a.
[0007]
FIG. 8 is a perspective view showing a book to which an IC card is attached. The IC card 5 has a tag shape and is attached to the lower part of the spine 4 a of the book 4. As shown in FIG. 9, the IC card 5 includes a loop-shaped card antenna 5a and an IC chip 5b connected thereto. The resonance card 7 is attached to the lower part of the cover of the book 4 so that the end is close to the end of the IC card 5. When the resonance card 7 resonates with the card antenna 5a and the book mounting direction is different, for example, even when it is difficult for the IC card and the loop antenna to directly communicate with each other, the resonance of the resonance card and the loop antenna enable communication. I have.
[0008]
10A and 10B show an arrangement relationship between each shelf board and a book, wherein FIG. 10A is a perspective view and FIG. 10B is a side view. As is clear from these figures, each of the shelves 1a, 1b with respect to the mounting position of the book 4 so that the surface of the card antenna of the IC card 5 is located within the vertical plane of the loop coils of the loop antennas 2A and 2B. Loop antennas 2A and 2B are provided.
[0009]
[Patent Document 1]
JP-A-2002-2917 (page 2, FIG. 1)
[0010]
[Problems to be solved by the invention]
As described above, in the related art, the conductor forming the loop antenna is formed of a wire or the like having a circular cross-section in the length direction. In this case, the magnetic field (magnetic flux) formed by the loop antenna has a substantially circular shape centered on the conductor as shown in FIG. 10B, and the range over which the magnetic field acts is a radius of hcm (diameter of 2hcm). ). However, when a shelf board such as a bookshelf stores an article to which an IC card is attached, the effective range of the magnetic field covers the entire area where the part of the article to which the IC card is attached may be located. Is preferred. That is, in a loop antenna attached to a shelf or the like, it is desired that the shape of the magnetic field be formed along a predetermined portion of the shelf. On the other hand, extending the loop antenna around the entire shelf is not preferable from the viewpoint of conductor cost reduction and power saving. Accordingly, in the conventional loop antenna as shown in FIGS. 6 and 10, the book 4 is placed at a predetermined position, for example, by placing the book 4 at a shallow position relative to the shelf. If there is a deviation, the magnetic field from the loop antenna does not reach the IC card 5, or the magnetic field from the IC card 5 does not reach the loop antenna, so that communication by the loop antenna becomes impossible, and therefore, high reliability is obtained. There is a problem that article management becomes impossible.
[0011]
Therefore, the present invention has been made to solve the above-described problem, and can easily expand the influence range of a magnetic field generated from a loop antenna with a simple configuration, or can generate an IC card generated from an IC card. For a reader / writer that can detect magnetic fields over a wide range, and can reliably communicate even if the position of the IC card is slightly shifted, and thus can perform highly reliable article management. It is intended to provide an antenna and an article management shelf.
[0012]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention relates to a reader / writer antenna configured to arrange a conductor so as to interlink with a magnetic field and perform wireless communication with an IC card, and includes a cross section of at least a part of the conductor. The shape has a shape different from other portions.
[0013]
Since the magnetic field is generated so as to go around the conductor, by making the cross-sectional shape of one part different from that of the other part, it is possible to change the magnetic field detection region or the magnetic field generation region range in that part, and The present invention can be applied to a usage mode of a simple reader / writer system.
[0014]
Further, in the reader / writer antenna according to the present invention, the cross-sectional shape of at least a part of the antenna is characterized by being formed in a flat shape longer in one direction than in the other direction.
[0015]
Further, in the reader / writer antenna according to the present invention, the one direction has a direction parallel to a plane of a flat plate portion on which the reader / writer antenna is provided.
[0016]
In the antenna for a reader / writer according to the present invention, the conductor is formed of a conductive paste applied on a plane.
[0017]
The present invention also relates to an article management shelf in which a reader / writer antenna for performing wireless communication with an IC card attached to an article is incorporated in a shelf for storing the article, wherein the reader / writer antenna has a magnetic field and a chain. The conductors are arranged so as to intersect, and the cross-sectional shape of at least a part of the conductor has a shape different from other parts.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings, taking an example of a case where the present invention is applied to an article (book) management shelf applied to book management.
FIG. 1 is a perspective view showing one article management shelf.
The article management shelf 10A has three shelves of shelves 1a, 1b, and 1c provided in a plurality of stages (three stages in the figure) in parallel with each other in the same manner as in the related art.
In each of the shelves 1a, 1b, 1c, a loop-shaped conductor forming a one-loop antenna 2A is attached to the lower surface of the shelf 1a, and a loop-shaped conductor forming a tool loop antenna 2B is formed on the lower surface of the shelf 1b. A loop-shaped conductor forming a four-loop antenna 2C is additionally provided on the lower surface of the shelf 1c.
[0019]
The one-loop antenna 2A has a rectangular shape along the outer shape of the shelf 1a, and the tool loop antenna 2B has a figure-eight shape having a shape folded at almost half the position of the shape of the shelf 1b. The antenna 2C has a shape that is folded at three positions of the shelf 1c, which are substantially divided into four. These loop antennas 2A, 2B, 2C are connected to the tuning circuit 3 described in the related art, and the tuning circuit 3 is connected to the reader / writer 6 shown in FIG.
[0020]
FIG. 3 is a diagram showing the one-loop antenna 2A in detail, and FIG. 4 is a sectional view taken along line BB of FIG. The one-loop antenna 2A has a part corresponding to the front side of the shelf (a part where the back where the IC card is attached when the book is put on the shelf) is a part of the one-loop antenna 2A from the back side when the book is inserted. Are formed in a flat plate shape that is wider (a> b), and has a flat shape whose cross section is longer in the book insertion direction and shorter in the vertical direction. For example, when an existing wooden or plastic shelf is used as the shelf, or when a glass shelf is used, this loop antenna is provided on the back of the shelf via the insulating film 21 as shown in FIG. It can be easily formed by, for example, applying a conductive paste to the insulating film 21.
[0021]
According to such a loop antenna, as shown in FIG. 4, the magnetic field (magnetic flux) 22 is formed along the pattern of the conductive paste, which is a conductor, so as to surround the pattern. Can be made wider than conventional circular conductors in cross section, and even if the placement position of a book or the like deviates over a wide range, the IC card can surely detect the magnetic field. A magnetic field can be detected. Thereby, communication reliability can be improved. That is, according to the present invention, in one loop antenna, the cross-sectional shape of only the conductor portion corresponding to the position where the magnetic field detection range needs to be widened is extended (expanded) by extending the detection range. Thus, it is possible to cover a wide range of magnetic field detection using the minimum conductive material. According to this example, the influence range of the magnetic field can be expanded from about 2 h to a + 2 h in the depth direction on the front side of the shelf, and the value of a can also be increased in the height direction (perpendicular to the shelf). Can be extended to the height region corresponding to. The value of a (the cross-sectional width of the conductor constituting the loop antenna) is determined by considering the position of the IC card in the storage of the article in consideration of the shelf board, the articles to be stored therein, and the mounting position of the IC card used therein. It can be set based on how much it changes.
[0022]
As shown in FIG. 5, similarly to the one-loop antenna 2A, also for the tool loop antenna 2B and the four-loop antenna 2C, a portion located on the near side of the shelf, which is a part thereof, is formed in a flat plate shape, and its cross-sectional shape is It is formed in a flat shape that is long in the book insertion direction and short in the up and down direction.
[0023]
In the present embodiment, the reason why one-loop, tool-loop, and four-loop antennas are provided in each of the three-stage management shelves will be described below. The magnetic flux interlinking in each of the loop antennas 2A, 2B, and 2C is as follows. For example, in FIG. 2, when magnetic fluxes Φ1 and Φ2 are generated in the four-loop antenna 2C as shown in FIG. 2C, they are linked to the tool loop antenna 2B as shown in FIG. These magnetic fluxes cancel each other out (Φ3 = 0), no induced electromotive force is generated in the tool loop antenna 2B, and the one-loop antenna 2A is linked as shown in FIG. However, these magnetic fluxes are mutually canceled and canceled out (Φ4 = 0), and the induced electromotive force is generated in the one-loop antenna 2A. There. Of course, as is clear from FIG. 2, the relationship between the tool loop antenna 2B and the one-loop antenna 2A is the same, and the total number of magnetic fluxes generated by one loop antenna interlinking with the other loop antenna becomes zero. Also, generation of induced electromotive force is prevented.
[0024]
【The invention's effect】
As described in detail above, the present invention easily expands the influence range of the magnetic field generated from the loop antenna on the IC card within a predetermined range with a simple configuration and without requiring a large amount of conductive material. Or a predetermined range in which a magnetic field generated from the IC card can be detected can be easily widened. Therefore, even if the position of the IC card with respect to the loop antenna is slightly shifted, communication can be reliably performed. Accordingly, there is an effect that an antenna for a reader / writer and an article management shelf that can perform article management with excellent reliability can be provided.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an article management shelf according to the first embodiment.
FIG. 2 is a diagram showing an operation of the first embodiment.
FIG. 3 is a perspective view showing a one-loop antenna and a shelf board.
FIG. 4 is a sectional view taken along line BB of FIG. 3;
FIG. 5 is a perspective view showing a one-loop antenna, a tool loop antenna, and a four-loop antenna.
FIG. 6 is a perspective view showing a conventional article management shelf.
FIG. 7 is a circuit diagram showing a tuning circuit.
FIG. 8 is a perspective view showing a state in which an IC card is attached to a book.
FIG. 9 is a simplified configuration diagram showing an IC card.
FIG. 10 is a diagram illustrating an arrangement relationship between a loop antenna and a book.
[Explanation of symbols]
1a, 1b, 1c shelf board, 2A one loop antenna, 2B tool loop antenna, 2C four loop antenna, 4 books, 5 IC card, 6 reader / writer, 10A article management shelf, 21 insulating film.

Claims (5)

An antenna for a reader / writer configured to arrange a conductor so as to link with a magnetic field and perform wireless communication with an IC card,
An antenna for a reader / writer, wherein at least a part of the conductor has a cross-sectional shape different from that of another part. The antenna for a reader / writer according to claim 1,
The antenna for a reader / writer, wherein at least a part of the cross-sectional shape is formed in a flat shape longer in one direction than in another direction. The antenna for a reader / writer according to claim 2,
The antenna for a reader / writer, wherein the one direction has a direction parallel to a plane of a flat plate portion on which the reader / writer antenna is provided. The antenna for a reader / writer according to any one of claims 1 to 3,
The antenna for a reader / writer, wherein the conductor is formed of a conductive paste applied on a plane. An article management shelf in which a reader / writer antenna for performing wireless communication with an IC card attached to the article is incorporated in a shelf for storing the article,
The article management shelf, wherein the reader / writer antenna is configured by arranging a conductor so as to interlink with a magnetic field, and has a cross-sectional shape of at least a part of the conductor that is different from other parts.

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