JP2024013622A - reading system - Google Patents

Abstract

[Problem] When installing multiple antennas inside a box to read information from an RFID tag, the effect of installing multiple antennas can be fully achieved. [Solution] A reading system that reads information from an RFID tag attached to an item stored in a box having multiple inner wall surfaces facing in different directions, antennas 1a to 1c for reading information from the RFID tag are attached to each of the three inner wall surfaces, and the antennas 1a to 1c are positioned such that the straight lines extending from the center of the antennas in the direction in which the maximum gain of the antennas is obtained do not intersect with each other. [Selected Figure] Figure 2

Description

The present invention relates to a reading system that reads information from an RFID tag attached to an article housed in a box.

In recent years, RFID tags that can write and read information in a non-contact state have been used for various purposes. For example, a technology has been considered in which an RFID tag is attached to an item such as a product, and information is written to or read from the RFID tag to manage the item. When managing goods using RFID tags in this way, it is possible to write and read information from multiple RFID tags at once, making it possible to improve the efficiency of work related to goods management. .

Patent Document 1 discloses an electronic tag reading system that stores a document binding with an electronic tag attached in a storage box and manages the document binding by reading information from the electronic tag in an anechoic box. In the device disclosed in Patent Document 1, an electronic tag is attached to the document binding, an antenna is installed on each inner wall surface of the anechoic box, and the storage box containing the document binding is mounted on a circular rotating table inside the anechoic box. information is read from the electronic tag via the antenna. The anechoic box is equipped with a door for taking the storage box in and out, and a slide shaft allows the annular rotary table to be moved in and out of the anechoic box.

Japanese Patent Application Publication No. 2011-8708

By the way, as mentioned above, in the case where information is read from an RFID tag via an antenna, radio waves are emitted from the antenna, and when the RFID tag receives these radio waves, the RFID tag is activated and information is read. . At this time, the region where the maximum gain of the antenna can be obtained depends on the directivity of the antenna.

In the device disclosed in Patent Document 1, antennas are installed on each inner wall surface of the anechoic box. However, if the areas where the maximum gain of the antennas can be obtained largely overlap, for example, when the antennas are installed in opposing areas on two opposing surfaces, the RFID tag There is a problem that there is a high possibility that there will be a wasted area where it will not be possible to obtain sufficient gain for reading information, and the effect of installing a plurality of antennas will not be sufficiently obtained.

The present invention has been made in view of the problems of the conventional technology as described above, and includes a reading system that reads information from an RFID tag attached to an article housed in a box. An object of the present invention is to provide a reading system that can fully obtain the effects of installing a plurality of antennas when reading information from an RFID tag by installing a plurality of antennas.

In order to achieve the above object, the present invention has the following features:
A reading system that reads information from an RFID tag attached to an article housed in a box having a plurality of inner walls facing in different directions, the reading system comprising:
An antenna for reading information from the RFID tag is attached to each of at least two of the plurality of inner wall surfaces,
The antennas attached to the inner wall surface are in a positional relationship such that straight lines extending from the central portion of the antenna in a direction in which the maximum gain of the antenna can be obtained do not intersect with each other.

In the present invention configured as described above, in a reading system that reads information from an RFID tag attached to an article housed in a box having a plurality of inner wall surfaces facing in different directions, At least two antennas are attached to each of the inner walls, and information is read from the RFID tag via these antennas. Since the straight lines extending in the direction of acquisition do not intersect with each other, the area where the maximum gain of the antenna can be obtained does not overlap significantly between multiple antennas. This reduces the possibility that there will be a region where it is not possible to obtain sufficient gain to read information from the antenna, and it becomes possible to fully obtain the effects of installing a plurality of antennas.

Additionally, if the antennas are attached to three or more inner walls of the box, there will be areas where it is not possible to obtain sufficient gain to read information from the RFID tag inside the box in which the item is housed. The possibility of this occurring is further reduced.

In addition, if the inner wall surfaces on which the antennas are attached face in directions perpendicular to each other, the directions in which the maximum gain of the antennas can be obtained will be perpendicular to each other, and this will also prevent RFID The likelihood that there will be regions where there is not enough gain to read information from the tag is reduced.

Further, for example, the box may be a rectangular parallelepiped or a cube.

In addition, the box body is composed of a drawer that can accommodate items with RFID tags attached, and a material that reflects or absorbs radio waves, or is surrounded by a material that reflects radio waves or a material that absorbs radio waves. The drawer has a drawer accommodating body that accommodates the drawer so that it can be taken out and taken out, an antenna is attached to the inner wall surface of the drawer accommodating body, and the drawer has a bottom plate on which articles to be stored in the drawer are placed, and four parts of the bottom plate. Among the edges, the side plate is attached to the edge that is the front side when the drawer is pulled out from the drawer storage body, and the side plate is installed to extend along the edge in the area above the other three edges of the bottom plate. the side plate is made of a material that reflects radio waves or a material that absorbs radio waves, or is covered with a material that reflects radio waves or a material that absorbs radio waves, and the bottom plate is made of an insulating material. If so, items with RFID tags attached and stored in a box can be managed by reading information from the RFID tag using radio waves via an antenna attached to the inner wall of the box. At this time, even if the RFID tag attached to the article is in contact with the bottom plate of the drawer when the article is placed on the bottom plate of the drawer, information can be read from the RFID tag.

In addition, the box body is composed of a drawer that can accommodate items with RFID tags attached, and a material that reflects or absorbs radio waves, or is surrounded by a material that reflects radio waves or a material that absorbs radio waves. The drawer has a drawer accommodating body that accommodates the drawer so that it can be taken out and taken out, an antenna is attached to the inner wall surface of the drawer accommodating body, and the drawer has a bottom plate on which articles to be stored in the drawer are placed, and four parts of the bottom plate. It has four side plates attached to each end, and among the four side plates, the front side plate, which is the front side when the drawer is pulled out from the drawer container, is made of a material that reflects radio waves or a material that absorbs radio waves. or is covered with a material that reflects radio waves or absorbs radio waves, and if the three side plates other than the front side plate and the bottom plate are made of insulating material, an RFID tag is attached as above. The items stored in the box can be managed by reading information from the RFID tag using radio waves via an antenna attached to the inner wall of the box. By placing the RFID tag on the item, even if the RFID tag attached to the item is in contact with the bottom plate of the drawer, information can be read from the RFID tag.

According to the present invention, in a reading system that reads information from an RFID tag attached to an article housed in a box having a plurality of inner wall surfaces facing in different directions, at least two of the inner wall surfaces of the plurality of inner wall surfaces are The antennas, each attached to read information from an RFID tag, are positioned so that the straight lines extending from the center of the antenna in the direction where the maximum gain of the antenna can be obtained do not intersect with each other, so that the maximum gain of the antenna is There is a possibility that the obtained area will not overlap significantly between multiple antennas, and as a result, there will be an area where it is not possible to obtain sufficient gain to read information from the RFID tag inside the box in which the item is housed. is reduced, and the effects of installing multiple antennas can be fully obtained.

Furthermore, in cases where antennas are attached to three or more inner walls of the box, it becomes impossible to obtain sufficient gain to read information from the RFID tag inside the box in which the item is housed. The possibility that the area will occur can be further reduced.

In addition, if the inner wall surfaces on which the antennas are attached face in directions perpendicular to each other, the directions in which the maximum gain of the antennas can be obtained will be perpendicular to each other, and as a result, even within the box body in which the item is housed, The possibility that there will be regions where sufficient gain cannot be obtained to read information from the RFID tag is reduced.

In addition, the box body is composed of a drawer that can accommodate items with RFID tags attached, and a material that reflects or absorbs radio waves, or is surrounded by a material that reflects radio waves or a material that absorbs radio waves. The drawer has a drawer accommodating body that accommodates the drawer so that it can be taken out and taken out, an antenna is attached to the inner wall surface of the drawer accommodating body, and the drawer has a bottom plate on which articles to be stored in the drawer are placed, and four parts of the bottom plate. Among the edges, the side plate is attached to the edge that is the front side when the drawer is pulled out from the drawer storage body, and the side plate is installed to extend along the edge in the area above the other three edges of the bottom plate. the side plate is made of a material that reflects radio waves or a material that absorbs radio waves, or is covered with a material that reflects radio waves or a material that absorbs radio waves, and the bottom plate is made of an insulating material. In some cases, items with RFID tags attached and stored in a box can be managed by reading information from the RFID tag using radio waves via an antenna attached to the inner wall of the box. At that time, even if the RFID tag attached to the article is in contact with the bottom plate of the drawer when the article is placed on the bottom plate of the drawer, information can be read from the RFID tag.

In addition, the box body is composed of a drawer that can accommodate items with RFID tags attached, and a material that reflects or absorbs radio waves, or is surrounded by a material that reflects radio waves or a material that absorbs radio waves. The drawer has a drawer accommodating body that accommodates the drawer so that it can be taken out and taken out, an antenna is attached to the inner wall surface of the drawer accommodating body, and the drawer has a bottom plate on which articles to be stored in the drawer are placed, and four parts of the bottom plate. It has four side plates attached to each end, and among the four side plates, the front side plate, which is the front side when the drawer is pulled out from the drawer container, is made of a material that reflects radio waves or a material that absorbs radio waves. , or is covered with a material that reflects radio waves or a material that absorbs radio waves, and the three side plates other than the front side plate and the bottom plate are made of insulating material, the same applies to RFID tags. can be managed by reading information from the RFID tag using radio waves via an antenna attached to the inner wall of the box. By placing the RFID tag on the bottom plate of the drawer, information can be read from the RFID tag even if the RFID tag attached to the item is in contact with the bottom plate of the drawer.

1 is a diagram showing the overall configuration of an embodiment of a reading system of the present invention. FIG. 2 is a diagram showing a detailed configuration of the box shown in FIG. 1. FIG. 2A and 2B are diagrams showing the attachment position of the antenna to the drawer housing in the reading system shown in FIG. 2, in which (a) is a view seen from the direction of arrow A in FIG. 2, and (b) is a view seen from the direction of arrow B in FIG. 2, (c) is a view seen from the direction of arrow C in FIG. 2. FIG. 2 is a block diagram showing the configuration of the RFID reader shown in FIG. 1. FIG. FIG. 2 is a block diagram showing the configuration of the management personal computer shown in FIG. 1. FIG. FIG. 2 is a diagram for explaining articles that are housed in a box and are to be managed by the reading system shown in FIG. 1; 2 is a flowchart for explaining processing when managing articles using the reading system shown in FIG. 1. FIG. 3 is a diagram for explaining a maximum gain region of the antenna shown in FIG. 2. FIG. FIG. 3 is a diagram showing the mounting position of the antenna when the reading performance through the antenna is compared by changing the mounting position of the antenna to the top plate and side plate of the drawer container in the box shown in FIG. 2; It is a figure showing other embodiments of the box used for the reading system of the present invention.

Embodiments of the present invention will be described below with reference to the drawings.

<Overall composition>
FIG. 1 is a diagram showing the overall configuration of an embodiment of a reading system of the present invention. FIG. 2 is a diagram showing a detailed configuration of the box body 10 shown in FIG. 1, and shows a state in which the drawer 20 is pulled out from the drawer container 30.

As shown in FIGS. 1 and 2, this embodiment includes antennas 1a to 1c attached to a box 10, an RFID reader 40, and a management personal computer 50.

The box 10 has a rectangular parallelepiped shape and includes a drawer 20 and a drawer container 30.

The drawer 20 is capable of storing articles attached with RFID tags, which will be described later, and includes a bottom plate 22, a side plate 21, and guides 23a to 23c and 24a to 24c.

The bottom plate 22 has a rectangular shape and is made of an insulating material such as resin, on which an article to which an RFID tag is attached is placed.

The side plate 21 is made of a material that reflects radio waves or a material that absorbs radio waves, and is attached to the near side when the drawer 20 is pulled out from the drawer container 30 among the four edges of the bottom plate 22. There is. A handle 25 is attached to the side plate 21 on the outside surface of the box 10, and by pulling the handle 25, the drawer 20 can be pulled out from the drawer container 30. Note that the side plate 21 is not made of a material that reflects radio waves or a material that absorbs radio waves, but may be covered with a material that reflects radio waves or a material that absorbs radio waves.

The guides 23a to 23c are provided on three edges of the bottom plate 22 other than the edge to which the side plate 21 is attached, extending along the edges. The guides 24a to 24c are provided above the guides 23a to 23c, spaced apart from the guides 23a to 23c by a predetermined distance, and parallel to the guides 23a to 23c.

The drawer container 30 includes a rectangular bottom plate 32, side plates 33a to 33c provided upright on three sides of the bottom plate 32, and end sides facing the bottom plate 32 and in contact with the bottom plate 32 of the side plates 33a to 33c. It has a top plate 31 which is in contact with the end side opposite to the top plate 31, and the side where the side plates 33a to 33c are not provided is open. The drawer container 30 is configured to be able to accommodate the drawer 20 from its open surface. These bottom plate 32, side plates 33a to 33c, and top plate 31 are each made of a material that reflects radio waves or a material that absorbs radio waves. Note that these bottom plate 32, side plates 33a to 33c, and top plate 31 are not made of a material that reflects radio waves or a material that absorbs radio waves, but are covered with a material that reflects radio waves or a material that absorbs radio waves. You can leave it there.

Rails 34a to 34b are attached to the inner surfaces of the box body 10, respectively, on two of the three side plates 33a to 33c that face each other. The rails 34a to 34b extend in the direction in which the drawer 20 is pulled out from the drawer container 30, and by engaging with the guides 24a and 24c of the drawer 20, the drawer 20 can be taken in and out of the drawer container 30. .

Antennas 1a to 1c are attached to the inner surfaces of the top plate 31 and the side plates 33b, 33c, which are the inner walls of the box 10, respectively. Details of the attachment positions of the antennas 1a to 1c to the top plate 31 and side plates 33b and 33c will be described later.

The RFID reader 40 is electrically connected via cables to the antennas 1a to 1c attached to the top plate 31 and side plates 33b and 33c of the drawer housing 30, and by emitting radio waves from the antennas 1a to 1c. , information is read from RFID tags attached to articles stored in the drawer 20 via antennas 1a to 1c. The RFID reader 40 can read information from all the RFID tags attached to the items stored in the drawer 20 via at least one of the antennas 1a to 1c using the output of radio waves radiated from the antennas 1a to 1c. The value is set to .

The management computer 50 is electrically connected to the RFID reader 40 via a cable, and the RFID reader 40 reads information from the RFID tags attached to the items stored in the drawer 20 via the antennas 1a to 1c. In this way, the articles stored in the drawer 20 are managed.

<Attachment positions of antennas 1a to 1c to drawer container 30>
FIG. 3 is a diagram showing the mounting positions of the antennas 1a to 1c in the reading system shown in FIG. 2 is a view seen from the direction of arrow B in FIG. 2, and (c) is a view seen from the direction of arrow C in FIG.

As described above, the antenna 1a is attached to the top plate 31 of the drawer container 30, the antenna 1b is attached to the side plate 33b of the drawer container 30, and the antenna 1c is attached to the side plate 33c of the drawer container 30.

Here, as shown in FIG. 3(a), if a straight line 2a is extended perpendicularly to the front direction of the antenna 1a from the central part of the antenna 1a attached to the top plate 31, this straight line 2a is attached to the side plate 33b. It does not intersect with the straight line 2b extending perpendicularly from the central part of the antenna 1b to the front direction of the antenna 1b. Furthermore, when a straight line 2c is extended perpendicularly to the front direction of the antenna 1c from the central part of the antenna 1c attached to the side plate 33c, this straight line 2c also extends from the central part of the antenna 1b attached to the side plate 33b to the front of the antenna 1b. It does not intersect with the straight line 2b extending perpendicularly to the direction.

In addition, as shown in FIG. 3(b), a straight line 2a extending perpendicularly from the center of the antenna 1a attached to the top plate 31 to the front direction of the antenna 1a corresponds to the center of the antenna 1c attached to the side plate 33c. It does not intersect with the straight line 2c extending perpendicularly to the front direction of the antenna 1c. Further, a straight line 2b extending perpendicularly from the central part of the antenna 1b attached to the side plate 33b to the front direction of the antenna 1b also extends perpendicularly from the central part of the antenna 1c attached to the side plate 33c to the front direction of the antenna 1c. It does not intersect straight line 2c.

Furthermore, as shown in FIG. 3(c), a straight line 2b extending perpendicularly from the center of the antenna 1b attached to the side plate 33b to the front direction of the antenna 1b is connected to the center of the antenna 1a attached to the top plate 31. It does not intersect with the straight line 2a extending perpendicularly to the front direction of the antenna 1a. Further, a straight line 2c extending perpendicularly from the central part of the antenna 1c attached to the side plate 33c to the front direction of the antenna 1c also extends perpendicularly from the central part of the antenna 1a attached to the top plate 31 to the front direction of the antenna 1a. It does not intersect with straight line 2a.

In this way, the antennas 1a to 1c attached to the top plate 31 and side plates 33b, 33c of the drawer container 30 are such that a straight line extending perpendicularly from the central part of the antenna to the front direction of the antenna is similar to that of the other antennas. It is attached in a twisted position that does not intersect with a straight line extending perpendicularly from the central portion in the front direction. At this time, if the guides 23a to 23c and 24a to 24c are made of a material that reflects radio waves or a material that absorbs radio waves, the antennas 1a to 1c are placed in the state in which the drawer 20 is accommodated in the drawer container 30. It is preferable to attach it at a position that does not overlap the guides 23a to 23c and 24a to 24c.

<Configuration of RFID reader 40>
FIG. 4 is a block diagram showing the configuration of the RFID reader 40 shown in FIG. 1.

As shown in FIG. 4, the RFID reader 40 shown in FIG. 47, and a tag data reception processing section 48.

The duplexer 41 transmits the signal output from the RF transmitter 46 as a radio signal via the antennas 1a to 1c, and outputs the radio signal received by the antennas 1a to 1c to the RF receiver 47.

The tag data transmission processing unit 42 outputs a signal for detecting an RFID tag during polling, and also outputs a signal for reading information from the RFID tag by non-contact communication.

The digital signal converter 43 converts the signal output from the tag data transmission processor 42 into an analog signal and outputs it to the RF transmitter 46, and also converts the signal received by the RF receiver 47 into a digital signal. and outputs it to the tag data reception processing section 48.

The communication unit 44 transmits and receives information to and from the management personal computer 50.

The RF transmitter 46 transmits the signal converted into an analog signal by the digital signal converter 43 onto a carrier wave via the duplexer 41 and the antennas 1a to 1c.

The RF receiving section 47 receives a response signal from the RFID tag in response to the signal transmitted from the RF transmitting section 46 via the antennas 1a to 1c and the duplexer 41.

The tag data reception processing unit 48 transmits the signal converted into a digital signal by the digital signal conversion unit 43 to the management personal computer 50 via the communication unit 44 as information read from the RFID tag.

<Configuration of management computer 50>
FIG. 5 is a block diagram showing the configuration of the management personal computer 50 shown in FIG. 1. As shown in FIG. Note that, in FIG. 5, illustrations and explanations of configurations of the management personal computer 50 that are not directly related to the present invention are omitted.

The management personal computer 50 shown in FIG. 1 has a communication section 51, a reading control section 56, an article management section 54, and an output section 55, as shown in FIG.

The communication unit 51 transmits and receives information to and from the RFID reader 40 .

The reading control unit 56 transmits a command to read information from the RFID tag to the RFID reader 40 via the communication unit 51, and also transmits the information read from the RFID tag by the RFID reader 40 via the communication unit 51. Receive.

The article management section 54 manages the articles stored in the box 10 based on information received from the RFID reader 40 via the communication section 51 by the reading control section 56 . For example, the article management section 54 has a database in which data related to articles housed in the box 10 is registered, and the information registered in this database and the information received from the RFID reader 40 via the communication section 51. By comparing the items, the items stored in the box 10 are managed.

The output unit 55 is comprised of a display or the like, and displays and outputs the management status of articles by the article management unit 54.

In this embodiment, the management personal computer 50 will be explained as an example, but any control device such as a computer capable of controlling the RFID reader 40, including a portable terminal etc., may have the above-mentioned configuration. Bye. Further, the configuration of the management personal computer 50 described above may be installed in the RFID reader 40.

<Processing in the reading system>
Below, a description will be given of a process for managing articles using the reading system configured as described above.

First, the articles contained in the box 10 and to be managed will be explained.

FIG. 6 is a diagram for explaining articles stored in the box 10 and to be managed by the reading system shown in FIG. be.

As shown in FIG. 6, articles 70 are arranged vertically and horizontally in the box 10 of the reading system shown in FIG. For example, as shown in FIG. 6, it is conceivable that a total of 48 articles 70 are stored in the drawer 20 by arranging them in four rows and stacking them in three stages. Each of the articles 70 housed in the drawer 20 is attached with an RFID tag 60 for management by pasting it on its top surface. Note that in the example shown in FIG. 6, the RFID tag 60 is attached to the top surface of the article 70, but the RFID tag 60 may be attached to the side or bottom of the article 70. . A unique ID is written in the RFID tag 60, and in the article management section 54 of the management computer 50, this unique ID corresponds to information regarding the article to which the RFID tag 60 having the unique ID is attached. It is managed accordingly.

Next, a process for managing articles using the reading system shown in FIG. 1 will be described using a flowchart.

FIG. 7 is a flowchart for explaining processing when managing articles using the reading system shown in FIG. Note that a description of the polling process performed by the RFID reader 40 prior to reading information from the RFID tag 60 will be omitted.

When managing articles using the reading system shown in FIG. sent to.

In the RFID reader 40, a command transmitted from the reading control unit 56 via the communication unit 51 is received via the communication unit 44, and when the RFID tag 60 is detected by polling processing (step S1), the command is received. According to the command, a signal for reading information from the RFID tag 60 is output from the tag data transmission processing section 42, and is converted into an analog signal by the digital signal conversion section 43. At this time, the information read from the RFID tag 60 becomes the unique tag ID stored in the RFID tag 60.

Thereafter, in the RF transmitting section 46, the signal converted into an analog signal by the digital signal converting section 43 is carried on a carrier wave and transmitted via the duplexer 41, thereby transmitting power from the RFID reader 40 to the RFID tag 60. is supplied, and a command to transmit the tag ID is transmitted to the RFID tag 60 (step S2). At this time, the output of the radio waves radiated from the antennas 1a to 1c is set to a value that allows information to be read from all RFID tags 60 present in the box body 10 via the antennas 1a to 1c. , information can be read from all the RFID tags 60 attached to the articles 70 housed in the drawer 20 without missing any information. Note that the articles 70 to which the RFID tags 60 are attached are housed in the drawer 20 in rows and columns, as described above. Therefore, when executing the process of reading information from the RFID tag 60, the output of radio waves radiated from the antennas 1a to 1c is transmitted to the RFID tag 60 present in the box body 10 through each of the antennas 1a to 1c. It is not necessary to set a value that allows information to be read from each, and information from all RFID tags 60 present in the box 10 can be read via at least one of the antennas 1a to 1c. It is sufficient if the value is set to .

When the command transmitted from the RFID reader 40 is received by the RFID tag 60 via the antennas 1a to 1c (step S3), the unique ID is transmitted from the RFID tag 60 as a response signal to the RFID reader 40 (step S3). S4). At this time, since the bottom plate 22 of the drawer 20 is made of an insulating material such as resin, when the article 70 is placed on the bottom plate 22 of the drawer 20, the RFID tag 60 affixed to the article 70 is transferred to the drawer 20. Even if the user contacts the bottom plate 22 of the RFID tag 60, information can be read from the RFID tag 60.

When the unique ID of the RFID tag 60 is transmitted as a response signal from the RFID tag 60 to the RFID reader 40 via at least one of the antennas 1a to 1c, the RFID reader 40 transmits the response signal from the RFID tag 60 to the antenna 1a. ~1c, the unique ID of the RFID tag 60 is received by the RF receiver 47 via the duplexer 41 (step S5), and is converted into a digital signal by the digital signal converter 43. Thereafter, in the tag data reception processing section 48, the unique ID of the RFID tag 60 converted into a digital signal is transmitted to the management personal computer 50 via the communication section 44 (step S6).

When the unique ID of the RFID tag 60 transmitted from the RFID reader 40 is received by the reading control unit 56 via the communication unit 51 of the management PC 50 (step S7), the article management unit 54 registers it in the database. By comparing the received information with the information received by the reading control unit 56 via the communication unit 51, the article 70 housed in the box 10 is managed (step S8). It is conceivable that the management state of the article 70 is displayed and outputted in the article management section 54 via the output section 55.

Reading of information from the RFID tag 60 as described above is performed while the drawer 20 is housed in the drawer container 30. In this case, since the side plate 21 of the drawer 20, the bottom plate 32, the side plates 33a to 33c, and the top plate 31 of the drawer container 30 are each made of a material that reflects radio waves or a material that absorbs radio waves, the box Information is read only from the RFID tag 60 affixed to the article 70 housed in the box 10 via the antennas 1a to 1c provided inside the box 10. This will prevent information from being read from an untargeted RFID tag via the antennas 1a to 1c.

<Reading performance via antennas 1a to 1c>
The reading performance via the antennas 1a to 1c in this embodiment will be explained below.

FIG. 8 is a diagram for explaining the maximum gain regions of the antennas 1a to 1c shown in FIG. 2, and shows the maximum gain region of the antenna 1a. Note that the maximum gain regions of antennas 1b to 1c are also the same.

The antennas 1a to 1c shown in FIG. 2 have radio wave radiation directivity directed toward the front of the antennas 1a to 1c. Therefore, as shown in FIG. 8, the area extending from the central portion of the antennas 1a to 1c in the front direction is the maximum gain area 2 where the antennas 1a to 1c can obtain the maximum gain.

Therefore, an experiment was conducted to compare the reading performance via the antennas 1a to 1c by changing the attachment positions of the antennas 1a to 1c to the top plate 31 and side plates 33b, 33c of the drawer container 30 in the box 10 shown in FIG. Ta.

FIG. 9 shows a comparison of reading performance via the antennas 1a to 1c by changing the mounting positions of the antennas 1a to 1c on the top plate 31 and side plates 33b, 33c of the drawer container 30 in the box 10 shown in FIG. FIG. 2 is a diagram showing the mounting positions of antennas 1a to 1c.

In order to compare the reading performance depending on the mounting position of the antennas 1a to 1c in the box body 10 shown in FIG. The reading rate of information from the RFID tag 60 affixed to the article 70 housed in the drawer 20 of the box 10 was measured by changing the attachment position of 1c. At this time, in the drawer 20 of the box 10, Styrofoam blocks with RFID tags 60 affixed to the sides and bottom, one each, are placed as articles 70 in four rows vertically and horizontally, similar to the one shown in FIG. They were lined up one by one and stacked in three layers to accommodate a total of 48 pieces.

As shown in FIG. 9(a), as attachment pattern 1 of the antennas 1a to 1c, the antenna 1a is attached to the top plate 31 near the corner where the top plate 31 of the drawer container 30 and the side plates 33b, 33c are adjacent. Attachment: The antenna 1b was attached to the side plate 33b, and the antenna 1c was attached to the side plate 33c. As a result, in attachment pattern 1, a straight line extending perpendicularly from the central part of each of the antennas 1a to 1c to the front direction of that antenna intersects a straight line extending perpendicularly from the central part of the other antenna to the front direction. It is in a state.

In attachment pattern 1, the reading rate at which the unique ID was read from the RFID tag 60 attached to the article 70 housed in the drawer 20 of the box body 10 via the antennas 1a to 1c was about 44%.

As shown in FIG. 9(b), as attachment pattern 2 for antennas 1a to 1c, antenna 1a is attached to top plate 31 at the center of each of top plate 31 and side plates 33b, 33c of drawer container 30, and 1b was attached to the side plate 33b, and the antenna 1c was attached to the side plate 33c. As a result, in attachment pattern 2, a straight line extending perpendicularly from the central part of each of the antennas 1a to 1c to the front direction of that antenna intersects a straight line extending perpendicularly from the central part of the other antenna to the front direction. It is in a state.

In attachment pattern 2, the reading rate at which the unique ID was read from the RFID tag 60 affixed to the article 70 housed in the drawer 20 of the box 10 via the antennas 1a to 1c was about 92%.

As shown in FIG. 9(c), the attachment pattern 3 of antennas 1a to 1c is similar to that shown in FIGS. 2 and 3. The antenna 1a was attached at a position where a straight line extending perpendicularly to the front direction of the antenna 1a had a twisted positional relationship that did not intersect a straight line extending perpendicularly to the front direction of the antennas 1b, 1c from the central portions of the antennas 1b, 1c. In addition, in the side plate 33b of the drawer container 30, a straight line extending perpendicularly from the central part of the antenna 1b to the front direction of the antenna 1b extends perpendicularly from the central part of the antennas 1a, 1c to the front direction of the antenna 1a, 1c. The antenna 1b was attached at a position that had a twisted positional relationship that did not intersect with a straight line. In addition, in the side plate 33c of the drawer container 30, a straight line extending perpendicularly from the central part of the antenna 1c to the front direction of the antenna 1c extends perpendicularly from the central part of the antenna 1a, 1b to the front direction of the antenna 1a, 1b. The antenna 1c was attached at a position that had a twisted positional relationship that did not intersect with a straight line.

In attachment pattern 3, the reading rate at which the unique ID was read from the RFID tag 60 affixed to the article 70 housed in the drawer 20 of the box 10 via the antennas 1a to 1c was approximately 100%.

In this way, the antennas 1a to 1c attached to the top plate 31 and side plates 33b, 33c of the drawer container 30 are connected so that the straight line extending perpendicularly from the central part of the antenna to the front direction of the antenna is the same as that of the other antennas. When the antennas 1a to 1c are attached in a twisted position that does not intersect with a straight line extending perpendicularly from the central portion in the front direction, the antennas 1a to 1c are attached at a position where the antennas 1a to 1c are attached more easily than in other cases. High reading performance.

Here, as shown in FIG. 8, the antennas 1a to 1c in this embodiment have the directivity of emitting radio waves in the front direction of the antennas 1a to 1c, so that The region facing the direction is the maximum gain region 2 where the maximum gain can be obtained by the antennas 1a to 1c. Therefore, the antennas 1a to 1c are installed in a position where a straight line extending perpendicularly to the front direction from the center portion thereof has a twisted positional relationship that does not intersect a straight line extending perpendicularly to the front direction from the center portion of the other antennas. As a result, the antennas 1a to 1c are in a positional relationship in which straight lines extending from the central portion of the antenna in the direction in which the maximum gain of the antenna can be obtained do not intersect with each other. With such a configuration, the regions where the maximum gain of the antennas can be obtained are dispersed among the plurality of antennas 1a to 1c, and do not overlap greatly. As a result, the possibility that a region where sufficient gain cannot be obtained to read information from the RFID tag 60 will occur in the box 10 in which the article 70 is housed is reduced, and the plurality of antennas 1a to 1c You will be able to get the full effect of installing it.

In the experiment described above, one RFID tag 60 was pasted on the side and bottom of the Styrofoam block serving as the article 70, but as shown in FIG. Even in the case where the antennas 1a to 1c are attached, similar results can be obtained with respect to the difference in reading rate caused by changing the mounting position of the antennas 1a to 1c as described above. Furthermore, in the experiment described above, a Styrofoam block was used as the article 70 to which the RFID tag 60 is attached, but the article 70 shown in FIG. There are items stored in cases. However, even if something other than a Styrofoam block is used as the article 70 shown in FIG. 6, the same results will be obtained with respect to the difference in reading rate caused by changing the mounting positions of the antennas 1a to 1c as described above. be able to. However, if the article 70 to which the RFID tag 60 is attached is a metal case made of a material that blocks radio waves, it may not be possible to read the information (unique ID) from the attached RFID tag 60. sell.

(Other embodiments)
FIG. 10 is a diagram showing another embodiment of the box used in the reading system of the present invention, showing a state in which the drawer 120 is pulled out from the drawer container 130.

As shown in FIG. 10, this embodiment is a box 110 in which the structure of the drawer 120 is different from that shown in FIG.

The drawer 120 is capable of accommodating the article 70 to which the RFID tag 60 is attached, and has a bottom plate 122 and side plates 121, 123a to 123c.

The bottom plate 122 has a rectangular shape and is made of an insulating material such as resin, and the article 70 to which the RFID tag 60 is attached is placed.

The side plate 121 serves as a front side plate in the present invention. The side plate 121 is made of a material that reflects radio waves or a material that absorbs radio waves, and is attached to the near side when the drawer 120 is pulled out from the drawer container 130 among the four edges of the bottom plate 122. There is. A handle 125 is attached to the side plate 121 on the outside surface of the box 110, and by pulling the handle 125, the drawer 120 can be pulled out from the drawer container 130. Note that the side plate 121 is not made of a material that reflects radio waves or a material that absorbs radio waves, but may be covered with a material that reflects radio waves or a material that absorbs radio waves.

The side plates 123a to 123c are made of an insulating material, and are respectively attached to three edges of the bottom plate 122 other than the edge to which the side plate 121 is attached, among the four edges of the bottom plate 122.

The drawer container 130 has the same configuration as the drawer container 30 shown in FIG. 2 .

Also in the box 110 configured as described above, the article 70 to which the RFID tag 60 is attached is stored in the drawer 120, and the drawer 120 is stored in the drawer container 130, similarly to the case shown in FIG. In this state, information is read from the RFID tag 60 via the antennas 101a to 101c attached to the drawer container 130. At this time, similarly to what is shown in FIG. 2, the antennas 101a to 101c attached to the top plate 131 and side plates 133b and 133c of the drawer container 130 have straight lines extending perpendicularly to the front direction from the central part thereof. By installing the antennas 101a to 101c in a twisted position that does not intersect with a straight line extending perpendicularly to the front direction from the center of the other antennas, the maximum gain of the antenna can be The positional relationship is such that straight lines extending in the obtained direction do not intersect with each other. As a result, the regions where the maximum gain of the antennas can be obtained are dispersed among the plurality of antennas 101a to 101c, and do not overlap greatly. As a result, the possibility that a region where sufficient gain cannot be obtained to read information from the RFID tag 60 will occur in the box 110 in which the article 70 is housed is reduced, and the plurality of antennas 101a to 101c are You will be able to get the full effect of installing it. Furthermore, since the side plates 123a to 123c are made of an insulating material, even when the drawer 120 is housed in the drawer container 130, the RFID tag can be detected via the antennas 101a to 101c attached to the drawer container 130. Information can be read from 60.

In the embodiment described above, the directivity of the antennas 1a to 1c and 101a to 101c attached to the drawer containers 30 and 130 is oriented in the front direction of the antennas 1a to 1c and 101a to 101c. The area extending from the central portion of antennas 1a to 1c and 101a to 101c in the front direction is the maximum gain area where the maximum gain can be obtained by antennas 1a to 1c and 101a to 101c. Therefore, the antennas 1a to 1c and 101a to 101c have a twisted positional relationship in which a straight line extending perpendicularly from the central part of the antenna to the front direction does not intersect with a straight line extending perpendicularly from the central part of the other antenna to the front direction. By attaching the antennas 1a to 1c and 101a to 101c at such positions, the antennas 1a to 1c and 101a to 101c have a positional relationship in which straight lines extending from the center of the antenna in a direction in which the maximum gain of the antenna can be obtained do not intersect with each other. However, even for antennas whose directivity does not face in the front direction, multiple antennas are positioned so that straight lines extending from the center of the antenna in the direction where the maximum gain of the antenna can be obtained do not intersect with each other. If it is attached to , the same effect as above can be obtained.

Furthermore, in the embodiment described above, the three antennas 1a to 1c and 101a to 101c are attached to the top plates 31, 131 and the side plates 33b, 33c, 133b, 133c, which are the three inner wall surfaces of the drawer containers 30, 130. Although the above configuration has been described as an example, the antennas may be attached to two or more inner wall surfaces of the drawer containers 30 and 130, respectively. However, if the antennas are attached to each of the three inner walls of the box, there will be areas where it is not possible to obtain sufficient gain to read information from the RFID tag inside the box where the item is stored. The possibility can be further reduced. Furthermore, depending on the size of the drawer containers 30, 130, a plurality of antennas may be attached to one inner wall surface, or antennas may be attached to the inner wall surfaces of the drawers 20, 120.

Furthermore, in the above-described embodiments, the boxes 10 and 110 in which the articles 70 to which the RFID tags 60 are attached are housed have a rectangular parallelepiped shape. As long as the box has a plurality of inner wall surfaces, it is not limited to a rectangular parallelepiped, and may be a cube or a box whose inner wall surfaces are not perpendicular to each other. However, if the inner wall surfaces on which the antennas are attached are oriented in directions perpendicular to each other, the directions in which the maximum gain of the antennas can be obtained will be perpendicular to each other, and this will also prevent the inside of the box in which the item is stored. It is possible to reduce the possibility that a region will occur where sufficient gain cannot be obtained to read information from the RFID tag.

1a~1c, 101a~101c Antenna 2 Maximum gain area 2a~2c Straight line 10,110 Box 20,120 Drawer 21,121, 123a~123c Side plate 22,122 Bottom plate 23a~23c, 24a~24c Guide 25,125 Handle 30 , 130 Drawer container 31, 131 Top plate 32, 132 Bottom plate 33a to 33c, 133a to 133c Side plate 34a, 34b Rail 40 RFID reader 41 Common device 42 Tag data transmission processing section 43 Digital signal conversion section 44, 51 Communication section 46 RF Transmission section 47 RF reception section 48 Tag data reception processing section 50 Management personal computer 54 Article management section 55 Output section 56 Reading control section 60 RFID tag 70 Article

Claims (6)

A reading system that reads information from an RFID tag attached to an article housed in a box having a plurality of inner walls facing in different directions, the reading system comprising:
An antenna for reading information from the RFID tag is attached to at least two inner wall surfaces of the plurality of inner wall surfaces, respectively,
In the reading system, the antennas attached to the inner wall surface are in a positional relationship such that straight lines extending from a central portion of the antennas in a direction in which a maximum gain of the antennas can be obtained do not intersect with each other. The reading system according to claim 1,
The reading system, wherein the antennas are respectively attached to three or more inner wall surfaces of the box body. The reading system according to claim 1 or 2,
A reading system, wherein the inner wall surfaces to which the antennas are attached are oriented in directions perpendicular to each other. The reading system according to claim 3,
The reading system, wherein the box is a rectangular parallelepiped or a cube. The reading system according to claim 4,
The box body is
a drawer that can accommodate items to which the RFID tag is attached;
a drawer accommodating body that is made of a material that reflects radio waves or a material that absorbs radio waves, or is surrounded by a material that reflects radio waves or a material that absorbs radio waves, and that accommodates the drawer so that the drawer can be put in and taken out;
The antenna is attached to an inner wall surface of the drawer container,
The drawer is
a bottom plate on which items stored in the drawer are placed;
a side plate attached to one of the four edges of the bottom plate that is on the near side when the drawer is pulled out from the drawer container;
a guide provided in a region above the other three edges of the bottom plate and extending along the edges;
The side plate is made of a material that reflects radio waves or a material that absorbs radio waves, or is covered with a material that reflects radio waves or a material that absorbs radio waves,
A reading system, wherein the bottom plate is constructed from an insulating material. The reading system according to claim 4,
The box body is
a drawer that can accommodate items to which the RFID tag is attached;
a drawer accommodating body that is made of a material that reflects radio waves or a material that absorbs radio waves, or is surrounded by a material that reflects radio waves or a material that absorbs radio waves, and that accommodates the drawer so that the drawer can be put in and taken out;
The antenna is attached to an inner wall surface of the drawer container,
The drawer is
a bottom plate on which items stored in the drawer are placed;
and four side plates respectively attached to the four end sides of the bottom plate,
Among the four side plates, the front side plate, which is the front side when the drawer is pulled out from the drawer container, is made of a material that reflects radio waves or a material that absorbs radio waves, or is made of a material that reflects radio waves or a material that absorbs radio waves. covered with material that absorbs
A reading system, wherein three side plates other than the front side plate and the bottom plate are made of an insulating material.

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