JP2006025363A - Antenna for reader writer and article management system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna for a reader writer and an article management system for reading information of an IC tag, regardless of the direction of the IC tag attached to the article. <P>SOLUTION: In the article management system 10, an article stored in a management shelf 11 is managed by using an IC tag 31 and a reader writer 100 for communicating with the IC tag 31. A reader writer antenna 9 is assembled in a rear face plate 14 of the management shelf 11 so that radio communication with the IC tag 31 can be carried out. In this case, the reader writer antenna 9 has two or more antenna units, in which each loop antenna is arranged in the shape of chain, and two or more antenna units 9a, 9b are shifted in the chain direction and arranged in the same plane. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a reader / writer antenna suitable for a reader / writer that exchanges data with a non-contact type IC tag, and an article management system including the reader / writer antenna.

An article management system that manages an article by wireless communication using an IC tag and a reader / writer can send and receive information about the article while maintaining contact between the IC tag and the reader / writer. Compared with the management according to the above, since the management of the articles can be easily performed, it is applied to various article management systems.
In Patent Document 1, as an article management shelf suitable for application to a library or the like, an antenna unit of a reader / writer that performs wireless communication with an IC card attached to an article has a plurality of shelves for storing the article, respectively. In the built-in article management shelf, the antenna units have different shapes so as to cancel the magnetic fluxes between adjacent shelves. For example, in the case of having three shelf boards, the loop antenna arranged on the first shelf board is a one-loop antenna. The loop antenna disposed on the second shelf is a two-loop antenna, and the loop antenna disposed on the third shelf is a four-loop antenna.
JP 2002-02917 A

By the way, when the loop antenna is formed on the article management shelf as described above, depending on the direction of the IC tag attached to the article, information on the IC tag may not be read by the loop antenna attached to the management shelf.
This will be described with reference to the diagram showing the positional relationship between the magnetic field of the loop antenna and the IC tag shown in FIG.
As shown in FIGS. 7A and 7B, when the loop antenna 51 is formed on a certain plane 50, the direction of the electromagnetic field of the loop antenna 51 is a direction crossing the plane 50 as shown. For this reason, as shown in FIG. 7A, when the IC tag 60 is arranged in the horizontal direction with respect to the plane 50 on which the loop antenna 51 is formed, the IC tag 60 intersects the magnetic field of the loop antenna 50. Information on the IC tag 60 can be easily read by a reader / writer to which the antenna 51 is connected. On the other hand, when the IC tag 60 is arranged in a direction orthogonal to the plane 50 on which the loop antenna 51 is formed as shown in FIG. 7B, the IC tag 60 is parallel to the magnetic field of the loop antenna 50. Therefore, there is a drawback that it is difficult to read the information of the IC tag 60.
That is, in the article management system, depending on the orientation of the IC tag attached to the article, the information on the IC tag cannot be read by the loop antenna attached to the management shelf.
For this reason, for example, when an IC tag is attached to the back of the holder for storing files stored in the management shelf, the reader / writer loop antenna is attached to the management shelf so that information on the IC tag can be easily read. To the back plate (parallel to the IC tag on the back of the holder). However, when storing an article that does not have a surface parallel to the loop antenna provided on the back plate of the management shelf, such as a book, the IC tag attached to the article is in a posture orthogonal to the loop antenna, It becomes difficult to read the information of the IC tag. In such a case, it is necessary to change the installation location of the reader / writer loop antenna, and it is necessary to modify the management shelf.
Therefore, the present invention has been made in view of the above points, and an antenna for a reader / writer capable of reading information on an IC tag regardless of the orientation of the IC tag attached to an article, and such a reader. An object of the present invention is to provide an article management system using a writer antenna.

In order to achieve the above object, a reader / writer antenna according to claim 1 is a reader / writer antenna used for a reader / writer that communicates with an IC tag attached to an article, and a plurality of loop antennas are linked. And an antenna section constituted by a cross-connecting section in which the linear elements are insulatively crossed in a three-dimensional and X-shape between adjacent linear elements of adjacent loop antennas. It is characterized by.
According to a second aspect of the present invention, the antenna includes a plurality of the antenna portions, and is arranged in a three-dimensional manner so that the cross-connecting portions of the plurality of antenna portions do not overlap each other.
The reader / writer antenna according to claim 3 is configured so that the ratio of the length of the loop antenna to the length of the cross-connecting portion with respect to the chain direction is set to about 2: 1, so that the radio wave radiation surface of the antenna portion is set. Thus, the reading range of the IC tags arranged in the orthogonal direction is widened.
In the reader / writer antenna according to claim 4, the reading range of the IC tag arranged in a direction orthogonal to the radio wave radiation surface of the antenna unit is widened by forming a plurality of the cross-linking portions. Features.
According to a fifth aspect of the present invention, there is provided an article management system for managing an article to which an IC tag is attached. The management shelf provided with the reader / writer antenna according to claim 1, and the reader / writer antenna. A reader / writer that performs communication with the IC tag, an antenna switching unit that switches a plurality of antenna units provided in the reader / writer antenna, and a switching control unit that controls the antenna switching unit. It is characterized by providing.
The invention of the article management system according to claim 6 is characterized in that the switching control means switches the plurality of antennas alternately by controlling the antenna switching means.
The invention of the article management system according to claim 7 is characterized in that the reader / writer antenna is provided on a back plate or a shelf plate of the management shelf.

According to the reader / writer antenna of the present invention, there are provided a plurality of antenna sections configured by arranging loop antennas in a chain, and these antenna sections are arranged on the same plane and shifted in the chain direction. Information can be read regardless of the orientation of the IC tag.
According to the article management system of the present invention, the reader / writer antenna according to claim 1 is managed as an article management system that manages articles stored in a management shelf using a reader / writer that communicates with an IC tag. By incorporating it into the back plate of the shelf, information can be read regardless of the orientation of the IC tag attached to the article.

Hereinafter, embodiments of the present invention will be described.
FIG. 1 is a diagram showing a configuration of an article management system to which a reader / writer antenna according to an embodiment of the present invention is applied.
The article management system 10 shown in FIG. 1 includes a management shelf (furniture) 11 having a reader / writer antenna 9 for reading and writing management information of an IC tag (not shown) attached to the back of a holder 30, and an IC tag. A reader / writer 100 that reads and writes management information and a PC (control means) 50 that controls the reader / writer 100 are provided. The reader / writer 100 is connected to a reader / writer antenna 9 provided in the management shelf 11 via a cable 12.
The reader / writer antenna 9 is formed by two antenna portions 9a and 9b. The configuration of the reader / writer antenna 9 will be described later.
The switching circuit (antenna switching means) 15 is configured by a switch that can be switched from the outside. For example, the PC 50 or the reader / writer 100 performs switching control of the two antenna units 9a and 9b provided in the reader / writer antenna 9. ing. Further, in this example, the plurality of holders 30 are stored in the upper part of the shelf 13 that divides the upper and lower storage spaces of the management shelf 11, and information recorded on an IC tag (not shown) attached to the back of the holder 30 is managed. Reading is performed by a reader / writer antenna 9 attached to the back plate 14 of the upper accommodation space of the shelf 11.
Similarly, the shelf 13 is provided in the lower storage space of the management shelf 11, and the reader / writer antenna 9 is attached to the back plate 14.
The configuration of the management shelf 11 shown in FIG. 1 is merely an example, and the number of shelves can be arbitrarily set.

Next, the configuration of the reader / writer antenna according to the present embodiment provided in the management shelf 11 of the article management system 10 will be described with reference to FIGS.
FIG. 2 is a diagram showing a basic configuration of the reader / writer antenna according to the present embodiment. The antenna portion 9a shown in FIGS. 2 (a) and 2 (b) is formed by connecting four loop antennas 18a, 18b, 18c, and 18d in a state of being insulated on the surface of the back plate 14 made of metal or the like. . The intersection 19a of the loop antennas 18a and 18b, the intersection 19b of the loop antennas 18b and 18c, and the intersection 19c of the loop antennas 18c and 18d are formed so as to intersect three-dimensionally.
That is, the opposing linear elements 16a and 17b and the elements 16b and 17a of the adjacent loop antennas 18a and 18b are electrically connected by the cross connection portion 19a. That is, the cross-connecting portions 19a provided at appropriate positions in the middle portions of the elements 16a and 17b and 16b and 17a facing each other in parallel cross the linear elements in an X shape and are electrically insulated from each other at the crossing portions. It is configured as follows.
Similarly, the opposing elements of the adjacent loop antennas 18b and 18c are electrically connected by the cross connecting portion 19b, and the opposing elements of the loop antennas 18c and 18d are electrically connected by the cross connecting portion 19c. Yes. That is, the cross connection portion provided at an appropriate position in the middle of each element facing in parallel is configured to cross the linear elements in an X shape and to be electrically insulated from each other at the cross portion.
When the antenna portion 9a is formed in this way, a magnetic field as shown in the figure is formed by adjacent loop antennas. Therefore, if such an antenna unit 9a is applied to the reader / writer 100, even when the IC tag 31 is arranged so as to be orthogonal to the antenna unit 9a as shown in FIG. Information can be read. However, when the IC tag 31 is present, for example, at a position above the cross-connecting portion 19b (position indicated as the IC tag 31a), information can be read from the IC tag, but the IC tag 31 is located above the loop antenna portion 18b. Information cannot be read from the IC tag if it exists at the position (position indicated as IC tag 31b).

Of course, as shown in FIG. 2B, information can be read from the IC tag 31 even when the IC tag 31 is arranged in parallel with the antenna portion 9a. However, the IC tag 31 is connected to the loop antenna portion 18b. When the information is present in the upper position (position indicated as IC tag 31c), the information can be read from the IC tag, but the IC tag 31 is present in the upper position (position indicated as IC tag 31d) of the cross connection part 19b. In this case, information cannot be read from the IC tag.
Therefore, in the reader / writer antenna 9 of the present embodiment, the antenna section as shown in FIG. 2 is used so that an area where information cannot be read from the IC tag 31 as shown in FIG. 2 does not occur. A plurality of (for example, two) 9a are prepared, stacked in an insulated state on the same plane, and the information is read from the IC tag 31 by arranging the antenna portions 9a alternately by shifting the antenna portions 9a in the chain direction. It prevents the area that cannot be generated.
At this time, if the width (length) of the cross-linking portion 19 of the antenna portion 9b is too narrow, the width of the magnetic field generated in the direction perpendicular to the radio wave radiation surface (antenna surface) is narrow, and the radio wave radiation surface of the antenna portion 9a On the other hand, the range in which information can be read from the IC tag 31 arranged so as to be orthogonal to each other becomes narrow.
Therefore, in the reader / writer antenna 9 of the present embodiment, the width (length) of the cross connection portion 19 is widened, and information is read from the IC tag 31 arranged so as to be orthogonal to the antenna surface. I'm trying to widen the range I can. For example, by setting the ratio of the length a of the loop antenna 18 and the length b of the cross connection 19 to the chain direction of the antenna 9a to be approximately 2: 1, the direction orthogonal to the radio wave radiation surface of the antenna 9a. The reading range of the IC tag 31 arranged in the is widened.
Note that the length of the cross-connecting portion 19 can be arbitrarily set. For example, when the two antenna portions 9a and 9b are shifted and arranged, they are arranged in the horizontal and vertical directions with respect to the antenna surfaces of the antenna portions 9a and 9b. What is necessary is just to set to the width | variety (length) which can read information most from the IC tag 31 currently performed.
In addition, by providing a plurality of such cross-linking portions 19, the readable range of the IC tag 31 arranged in the direction orthogonal to the antenna surface is increased.
That is, the reader / writer antenna 9 according to the present embodiment includes a plurality of antenna portions 9a and 9b in which a plurality of cross connection portions 19 are provided and the width (length) of each cross connection portion 19 is appropriately set. The cross connecting portions 19 are arranged so as to be shifted in the chain direction so as not to overlap.

FIG. 3 is a diagram showing a configuration example of the reader / writer antenna 9 configured as described above. In the example shown in FIG. 3, the antenna portions 9a and 9b have different antenna shapes, but the antenna portions 9b are arranged so as to be shifted in the chain direction so that the cross-linking portions 19 of the antenna portions 9a are staggered. An antenna having the same function as is realized in the same plane size as the antenna portion 9a.
When the reader / writer antenna 9 formed in this way is connected to the reader / writer 100, a switching circuit 15 is provided between the reader / writer 100 and the reader / writer antenna 9, and the switching circuit 15 causes the reader / writer antenna 9 to be connected. By alternately switching the two antenna portions 9a and 9b constituting the IC tag 31, even when the IC tag 31 is arranged in two directions, the horizontal and vertical directions, with respect to the antenna surface of the reader / writer antenna 9. The information can be read from.
Here, the basic configuration of the reader / writer antenna according to the present embodiment will be further described with reference to FIG.
When an antenna is formed as in the present embodiment, the shape of each loop antenna is such that the antenna 20 that is most efficient when the loop areas on both sides are equal to the cross point as shown in FIG. Can be configured. That is, it is possible to configure the antenna 20 that can obtain the most efficient flow of magnetic flux and the effect of canceling the leakage electric field. Therefore, by combining the antenna 20 shown in FIG. 4A as shown in FIG. 4B, the reader / writer antenna of the present embodiment as shown in FIG. 4C can be formed. In this case, the length x of each loop antenna can be arbitrarily set. In addition, the number of loop antennas to be combined in forming the reader / writer antenna can be arbitrarily set. In this embodiment, the case where the loop antenna is formed so that the loop areas on both sides are equal to the cross point is taken as an example, but this is only an example, and the shape is arbitrarily changed depending on the application. Is possible.

The basic configuration and operation of the reader / writer and contacted IC tag used in the article management system of this embodiment will be described with reference to FIG.
FIG. 5 is a block diagram showing a configuration of an IC tag reader / writer. The IC tag reader / writer 100 shown in FIG. 5 is controlled by a computer (PC) 50 that sends and receives data to an external reader / writer 100 to control the entire system. The reader / writer 100 reads the transmission / reception device 1 that controls the communication protocol of data with the external computer 50, the control device 2 that controls the operation of the entire reader / writer 100, and the firmware that records the procedure for operating the control device 2. Memory device 3 for storing data, modulator 4 for modulating data from control device 2 on a carrier wave, input device 5 for inputting an operation command, and display device for displaying information controlled by control device 2 6, a power amplifier 7 that amplifies the command from the modulator 4, a detector demodulator 8 that converts the carrier wave received from the loop antenna 9 into binary data, and a power carrier wave and data for an IC tag (not shown) And a loop antenna 9 for receiving and transmitting the above.
Next, before describing the operation of the reader / writer 100 according to this configuration, the configuration of the paired IC tags will be described. FIG. 6 is a block diagram showing the configuration of the IC tag. The IC tag 200 receives the power carrier wave from the reader / writer 100, the transmission / reception circuit 21 that generates a write command read command, and the power carrier wave from the loop antenna 20 and rectifies it. From the power generation circuit 22 that converts the power into DC power, the memory device 23 that manages the storage of control firmware and data, the modulator 24 that modulates the transmission command from the control circuit 26 with a carrier wave, and the transmission / reception circuit 21 The detector 25 converts the carrier wave data into binarized data, and the control circuit 26 controls the overall operation of the IC tag 200. In addition to the ASK (Amplitude Shift Keying), the modulation system includes a PSK (Phase Shift Keying) system, an FSK (Frequency Shift Keying) system, and the like.

Next, each operation will be described with reference to FIGS. 5 and 6 together. When a power supply (not shown) is turned on, the reader / writer 100 starts an operation according to a program stored in the memory device 3 after the initial operation of the control device 2. First, initialization is performed. Next, in order to supply power to the IC tag 200, the control device 2 performs modulation by the modulator 4 when transmitting a command, and transmits a non-modulated signal from the power amplifier 7 when receiving a response from the IC tag 20. To do. The signal is radiated to the outside from the loop antenna 9 as an electromagnetic wave.
Next, when the IC tag 200 comes close to the reader / writer 100, the loop antenna 20 receives the power supply signal, rectifies the carrier wave by the power generation circuit 22 and converts it into DC power, and all the circuits in the tag To supply. When power is supplied and the control circuit 26 is driven, control is started in accordance with a program stored in the memory device 23.
Next, the control circuit 26 first demodulates the command from the transmission / reception circuit 21 by the detector 25 and converts it into a binary signal, and analyzes the command. As a result, when it is recognized that it is called, the response is modulated by the modulator 24 and transmitted from the loop antenna 20 via the transmission / reception circuit 21. The reader / writer 100 receives this response with the loop antenna 9, converts it into a binarized code with the detector demodulator 8, analyzes it with the control circuit 2, and recognizes that the IC tag 200 is a tag conforming to the standard. As a result, data is exchanged between the reader / writer 100 and the IC tag 200 thereafter.

In the present embodiment, the reader / writer antenna 9 has been described as being arranged so that the cross-connecting portions 19 of the two antenna portions 9a and 9b do not overlap, but three or more antenna portions are shifted. Of course, it is possible to arrange them. Even in such a case, the cross connection portions of the three or more antenna portions may be arranged in a three-dimensional manner so as not to overlap.
Further, it is not always necessary to provide a plurality of antenna units 9a. If information can be read from the IC tags 31 arranged in two directions, the horizontal and vertical directions, the antenna 10 for reader / writer is configured by one antenna unit 9a. It is also possible.
In addition, the cross-connecting portion in which the linear elements are insulatively intersected in a three-dimensional and X-shape does not mean a strict meaning of the X-shape, and a part of the opposing linear elements is Includes all intersecting configurations.
Further, in the present embodiment described so far, the reader / writer antenna 9 has been described as an example in which the reader / writer antenna 9 is disposed on the back plates 14 and 15 of the management shelf 11. Is possible.

1 is a configuration diagram of an article management system to which a reader / writer antenna according to an embodiment of the present invention is applied. It is the figure which showed the basic composition of the antenna for reader / writers which concerns on this Embodiment. It is the figure which showed the structure of the antenna for reader / writers which concerns on this Embodiment. It is the figure which showed the structure of the antenna for reader / writers which concerns on this Embodiment. It is the block diagram which showed the structure of the reader / writer for IC tags. It is a block diagram which shows the structure of an IC tag. It is the figure which showed the arrangement | positioning relationship between the magnetic field of a loop antenna, and an IC tag.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Transmission / reception apparatus, 2 Control apparatus, 3 Memory apparatus, 4 Modulator, 5 Input apparatus, 6 Display apparatus, 7 Power amplifier, 8 Detector demodulator, 9 Reader / writer antenna, 10 Article management system, 11 Management shelf (furniture) , 12 cables, 13 shelves, 14 15 back plate, 15 switching circuit, 17 base, 21 transmission / reception circuit, 22 power generation circuit, 23 memory device, 24 modulator, 25 detector, 26 control circuit, 30 holder, 31 IC Tag, 50 PC (control means), 100 reader / writer, 200 IC tag

Claims (7)

A reader / writer antenna used for a reader / writer that communicates with an IC tag attached to an article,
A plurality of loop antennas are arranged in a chain, and each linear element is constituted by a cross-connecting portion that is insulatively crossed in a three-dimensional and X-shape between opposing linear elements of adjacent loop antennas. An antenna for a reader / writer, characterized in that an antenna portion is provided.   2. The reader / writer antenna according to claim 1, wherein the reader / writer antenna is provided with a plurality of the antenna portions, and is three-dimensionally shifted so that the cross connection portions of the plurality of antenna portions do not overlap each other.   By setting the ratio of the length of the loop antenna with respect to the chain direction and the length of the cross-connecting portion to approximately 2: 1, reading of an IC tag arranged in a direction orthogonal to the radio wave radiation surface of the antenna portion 3. The reader / writer antenna according to claim 1, wherein the range is widened.   4. The reading range of the IC tag arranged in a direction orthogonal to the radio wave radiation surface of the antenna unit is widened by forming a plurality of the cross-linking units. 5. An antenna for a reader / writer as described in the paragraph.   2. An article management system for managing an article with an IC tag attached thereto, wherein the reader / writer communicates between the management shelf provided with the reader / writer antenna according to claim 1 and the IC tag by the reader / writer antenna. An article management system comprising: an antenna switching unit that switches a plurality of antenna units provided in the reader / writer antenna; and a switching control unit that controls the antenna switching unit.   6. The article management system according to claim 5, wherein the switching control unit switches the plurality of antennas alternately by controlling the antenna switching unit.   The article management system according to claim 5 or 6, wherein the reader / writer antenna is provided on a back plate or a shelf plate of the management shelf.

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