JP2010211537A - Media management system and reader/writer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide good communication without interference between adjacent antennas when a plurality of antennas for a reader/writer are arranged in proximity to each other. <P>SOLUTION: The invention is applied to a system which contains two or more media each including a noncontact radio tag and media cases. The system includes: a plurality of antennas (21a, 21b, 21c and so on) for the reader/writer which are arranged in compliance with each storage position at which the media or the media cases are disposed; and selection means which, among the plurality of antennas for the reader/writer, selects a antenna for the reader/writer used for communication. The antenna for the reader/writer selected by the selection means is defined as a first resonance frequency f1 corresponding to a radio communication frequency. The antenna for the reader/writer which is at least arranged in proximity to the antenna for the reader/writer defined as the first resonance frequency 1 is defined as a second resonance frequency f2 different from the first resonance frequency f1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a media management system that manages media such as disks stored in a case, and a reader / writer applied to the system.

  Conventionally, as a method for managing disc media such as CD (Compact Disc) and DVD (Digital Versatile Disc), an RFID (Radio Frequency IDentification) tag is pasted on a part of the disc, and information on the RFID tag is used when necessary. There is something to read and write. For example, in a place where many disk media are stored such as a library, an RFID tag in which each identification code is written is pasted on the surface of each disk to be stored. Then, when accepting lending or returning of a disk, the RFID tag of the disk is read by a reader / writer to manage lending. In this way, it is possible to identify the disk that is being rented and manage the disk easily.

  In this way, the RFID tag can be attached to each disk, and the disk can be managed by reading the RFID tag with a reader / writer when lending or returning the disk. It is necessary to read them close.

On the other hand, it has been proposed to read the RFID tag attached to each disk in a state where the disk is stored in a storage shelf (see Patent Document 1).
7 to 9 show an example of the system proposed previously.
First, as shown in FIG. 7A, a disc 1 to be managed such as a DVD is prepared, and a tag sheet 2 on which an RFID tag 2b and a coil antenna 2c are attached is prepared. Then, as shown in FIG. 7B, the tag sheet 2 is attached to the surface (the so-called label surface) opposite to the signal recording surface of the disk 1. In the example of FIG. 7, the tag sheet 2 is pasted around the hole 1 a at the center of the disk 1. The tag sheet 2 has a hole 2 a slightly larger than the hole 1 a of the disk 1.

  As shown in FIG. 7B, the tag sheet 2 is attached to the disk 1 and the vicinity of the center of the disk 1 (that is, the location of the tag sheet 2) is brought close to a reader / writer (not shown) so that the reader / writer In short-range wireless communication using electromagnetic induction, data is read from the memory in the RFID tag 2b, and data is written to the memory in the RFID tag 2b as necessary. Here, the short-range wireless communication between the reader / writer and the RFID tag 2b assumes a short distance of about several centimeters, for example.

  However, when the tag sheet 2 is directly attached to the disk 1 as shown in FIG. 7, the disk 1 is stored in a disk case formed of synthetic resin, and a plurality of disk cases are lined up and stored in a storage shelf. Therefore, reading with a reader / writer is difficult.

The technique described in Patent Document 1 solves this problem. As a disk case 10 formed of synthetic resin, a booster antenna 3 that connects the vicinity of the center of the stored disk and the end surface 17 of the case 10 is provided. It is provided.
The disc case 10 has a three-part structure of a lower case 11, a disc tray 13 disposed on the lower case 11, and an upper case 12 on the lid, and the disc tray 13 is joined to the lower case 11. .
A hole 1a (FIG. 7) of the disk 1 is fitted into the disk holding mechanism 15 at the center of the mounting surface 14 of the disk tray 13, and the disk 1 is held. The upper case 12 is attached so that the two fulcrum portions 18 are inserted into the holes 16 on the lower case 11 side and can be freely opened and closed.

  The booster antenna 3 is disposed between the lower case 11 and the disc tray 13. The booster antenna 3 has a first coil part 3a and a second coil part 3c, and both coil parts 3a and 3c are connected by a tuning circuit (not shown). The first coil portion 3 a is formed by winding a wire in a circular shape and is arranged on the back side of the disc holding mechanism 15 of the disc tray 13. The second coil portion 3 c is formed by winding a wire around a horizontally long rectangle and is disposed on an end surface (side surface) 17 of the lower case 11.

  By inserting the disc 1 with the tag sheet 2 pasted into the disc case 10 shown in FIG. 8, the reader / writer close to the end surface 17 of the disc case 10 passes the booster antenna 3 through the tag sheet 2. Communication with the RFID tag 2b.

That is, when the wireless communication state is shown in FIG. 9, the coil antenna 2c connected to the RFID chip 2b of the disk 1 via the tuning circuit 2d is close to the first coil portion 3a of the booster antenna 3 and can transmit and receive signals. Done.
The first coil portion 3a of the booster antenna 3 is connected to the second coil portion 3b via the tuning circuit 3b, and the second coil portion 3b is close to the coil antenna 4a of the reader / writer 4, Transmission / reception is possible with the reader / writer 4 side. The coil antenna 4a is connected to the main circuit 4c of the reader / writer 4 via the tuning circuit 4b, and outputs magnetic flux from the main circuit 4c to the coil antenna 4a side.

  Thus, the booster antenna 3 shown in FIG. 8 is attached to the disk case 1 and relayed by the booster antenna 3 as shown in FIG. 9, and the reader / writer is brought close to the end surface 17 of the disk case 1, Reading and writing of the RFID tag 2b attached to the disk 1 becomes possible.

  In Non-Patent Document 1, in the collection management of books and rentals in a library, RFID tags are affixed to corresponding products, and information on RFID tags is obtained in units of 10 to 20 using a shelf antenna and a high-power reader / writer. There is a description about performing batch reading.

JP 2008-207875 A

IT library system Hiroyuki Uchida http://www.uchida.co.jp/ulius/index.html

  A conventional library management system having a configuration as described in Non-Patent Document 1 uses a high output reader / writer of about 4 W, for example, and reads a plurality of RFID tags on a shelf antenna at a time. It is not a method of reading specific sheets. Therefore, it is difficult for a conventional system to determine and manage the exact storage position of each disk.

In order to read information from RFID tags attached to each disk placed on a storage shelf, etc., a plurality of reader / writer antennas are arranged corresponding to the number of disk cases to be stored. It is conceivable that the antenna is configured to perform wireless communication individually with the disk case side close to the antenna.
However, when a plurality of reader / writer antennas are arranged close to each other, the frequency of radio communication with each RFID tag is the same, so that each antenna has the same resonance frequency, but the same is placed in the vicinity. There is a problem that the resonance frequency antennas interfere with each other and cannot exhibit their original characteristics.

  The present invention has been made in view of the above points, and it is an object of the present invention to make it possible to satisfactorily communicate without interfering with neighboring antennas when a plurality of reader / writer antennas are arranged close to each other. And

The present invention is applied to a media management system that stores and manages a plurality of media or media cases each having a contactless wireless tag that performs wireless communication with an antenna connected to a reader / writer.
As a configuration, a plurality of reader / writer antennas arranged corresponding to respective storage positions where media or media cases are arranged, and a reader / writer that performs communication among the plurality of reader / writer antennas. Selecting means for selecting the antenna.
The reader / writer antenna selected by the selection means is set to a first resonance frequency corresponding to a frequency for performing wireless communication, and is disposed adjacent to at least the reader / writer antenna having the first resonance frequency. The reader / writer antenna is set to a second resonance frequency different from the first resonance frequency.

  According to the present invention, among a plurality of arranged reader / writer antennas, an antenna selected to perform wireless communication is at least adjacent to the selected antenna as a first resonance frequency for wireless communication. By setting the other antenna to a second resonance frequency different from the first resonance frequency, the antenna that performs wireless communication and the other antenna adjacent to the antenna do not interfere with each other. Therefore, even when a plurality of antennas are arranged side by side at a relatively narrow interval, each antenna can satisfactorily communicate wirelessly with a non-contact wireless tag adjacent thereto.

It is explanatory drawing which showed the example of the setting state of the resonant frequency by the example of one embodiment of this invention. 1 is a circuit diagram showing a circuit configuration example according to an example of an embodiment of the present invention. It is a perspective view which fractures | ruptures and shows a part of apparatus by the example of one embodiment of this invention. FIG. 4 is a perspective view showing a state in which the disk case is stored in the apparatus of FIG. 3. It is a block diagram which shows the system configuration example by one embodiment of this invention. It is the circuit diagram which showed the example of a circuit structure by the other example of one embodiment of this invention. It is explanatory drawing which shows the example of the state which affixed the tag sheet | seat on the disc. It is explanatory drawing which shows the structural example of the disk case with a booster antenna. It is a block diagram which shows the example of the communication state of a disc and a reader / writer.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, the tag sheet 2 in which the RFID chip 2b and the coil antenna 2c are arranged is pasted in the vicinity of the central portion of the disk 1 described in the background art section with reference to FIGS. Is used. A disk case 10 for storing the disk 1 is also prepared, which has a booster antenna 3 as shown in FIG. 8 and can communicate with the reader / writer antenna close to the end face 17 of the case. . In the present embodiment, the communication method in which the RFID chip 2b performs short-range wireless communication with the reader / writer via the booster antenna 3 is not particularly described, but has already been put into practical use for RFID. Various methods are applicable. Here, the frequency for wireless communication is 13.56 MHz as a resonance frequency, and communication is performed between the reader / writer and the RFID.

FIG. 1 is a diagram showing an outline of the storage shelf 20 of the present embodiment and the states of coil antennas 21a, 21b, 21c,... Arranged on the storage shelf 20 (resonance frequency setting state).
As shown in FIG. 1, a plurality of disk cases 10 a and 10 b are arranged side by side on the case placement surface 20 a of the storage shelf 20. The disk case 10a communicates with the RFID chip of the disk in the case by a reader / writer, and each surrounding disk case 10b does not communicate in the state of FIG.

  Coil antennas 21a, 21b, 21c,... Are embedded in the arrangement positions of the individual disk cases of the storage shelf 20. Each of the coil antennas 21a, 21b, 21c,... Of the present embodiment has a rectangular shape having a narrow width corresponding to the width of the bottom surface of the disk case, and is arranged at the same interval as the interval in which the disk case is stored.

  As shown in FIG. 1, assuming that wireless communication is performed between the RFID chip of the disk in the disk case 10a and the coil antenna 21c adjacent to the disk case 10a, the coil antenna 21c is wirelessly communicated with the reader / writer. Connect to the circuit. The connection with the wireless communication circuit is performed by a changeover switch 44 (see FIG. 5) described later.

Here, in this example, the coil antenna 21c has a resonance frequency of the first frequency f1, and the other coil antennas 21a, 21b, 21d, 21e, and 21f have a second frequency f2 that is different from the first frequency f1. And
The first frequency f1 is 13.56 MHz which is a frequency for performing wireless communication, and the second frequency f2 is a frequency different from this.
When the coil antenna that performs wireless communication is switched to another antenna, the coil antenna used for wireless communication at that time becomes the resonance frequency f1, and the remaining coil antennas change to the resonance frequency f2.
By setting the resonance frequency in this way, during the wireless communication by the coil antenna 21c, the other neighboring coil antennas 21a, 21b, 21d, and 21e all have a resonance frequency f2 different from the resonance frequency f1, and the coil antenna Mutual interference between 21c and another coil antenna can be prevented.

FIG. 2 is a diagram showing a circuit configuration of one coil antenna.
A transmission signal is supplied to the RF input terminal 51, and a resonance frequency switching signal is supplied to the control signal input terminal 52. RF input terminal 51 via a capacitor _{C 4} and the diode _{D 1,} Yes connected to one end of the coil _{L 1} and the capacitor _{C 1,} and connect the other end of the coil _{L 1} and the capacitor _{C 1} to the ground potential portion is there. Further to a connection point between the diode D ₁ and the coil L _1, Yes and connected to one end of the capacitor C _2, the other end of the capacitor C ₂ is, is connected to one fixed contact Sa of the switch S _1. Other fixed contact Sb of the switch S1, via the resistor R ₁ Yes connected to the ground potential portion, the movable contact Sm is directly is connected to the ground potential portion.

Connection state of the movable contact Sm of the switch S ₁ is controlled by the signal obtained at the control signal input terminal 52. That is, the control signal input terminal 52, resistor via a series circuit of R ₃ and coil L _2, Yes so connected to the connection point of the capacitor C ₄ and the diode D _1, a resistor R ₃ and the coil L ₂ in the signal obtained at the connection point, it is constituted to control the connection of the movable contact Sm switch S _1. Incidentally, the resistor to a connection point between R ₃ and the coil L _2, and one end of the resistor R ₂ at one end and the capacitor C ₃ is Yes connected, the other end of the resistor R ₂ at the other end and the capacitor C ₃ Is connected to the ground potential portion.
By such a configuration, the control signal when the signal obtained at the input terminal 52 is at high level "H", the switch S ₁ is turned on, the movable contact Sm becomes a connected state with the fixed contact Sa , a state in which the capacitor C ₂ is connected in parallel with the capacitor C _1. When the signal obtained at the control signal input terminal 52 is at the low level "L", the switch S ₁ is in the OFF state, the movable contact Sm becomes a connection state with the other fixed contact Sb.

By configuring the coil antenna in this way, the resonance frequency of the coil antenna is determined by the constants of the coil L ₁ and the capacitors C ₁ and C ₂ . However, the capacitor C ₂ is an element that is connected only when the switch S ₁ is in the on state. When the switch S ₁ is in the on state, the resonance frequency as the antenna is determined by the constants of the coil L ₁ and the capacitor C ₁ .

Here, when an example of the resonance frequency is shown, for example, the coil L ₁ = 1.1 μH, the capacitor C ₁ = 22 pF, and the capacitor C ₂ = 100 pF.
At this time, when the switch S ₁ is in the ON state, the resonance frequency f1 is determined by the following equations.
f1 = 1 / 2π√L × (C ₁ + C ₂ )
= 1 / 2π√1.1 × 122E-18
= 13.7 MHz
Also, when the switch S ₁ is in the OFF state, the resonance frequency f2 is determined by the following equations.
f2 = 1 / 2π√L × C ₁
= 1 / 2π√1.1 × 22E-18
= 32MHz

Thus, it is possible to switch by switching the switch _{S 1,} and 13.7MHz is the first resonance frequency f1, and a 32MHz which is the second resonance frequency f2.
Note that, by setting C ₁ >> C ₂ , the difference between the two resonance frequencies f1 and f2 increases. In order to prevent mutual interference during communication, it is important to increase the difference between the two resonance frequencies f1 and f2.

3 and 4 are diagrams showing a configuration example of the storage shelf 20 of the present embodiment in which the coil antenna is incorporated as described above.
In the storage shelf 20, the partition plates 23 are arranged on the bottom plate 22 at regular intervals, and one disk case 10 can be placed at a position partitioned by the partition plates 23. When the disk cases 10 are placed, the end face 17 (see FIG. 8) of each disk case 10 is set on the lower side. The end surface 17 is a surface on which the second coil portion 3c of the booster antenna 3 is disposed.

  Coil antennas 21 a, 21 b,..., 21 m, 21 n (n is an arbitrary integer) are built in the bottom plate 22 of the storage location of each disk case partitioned by the partition plate 23. The plurality of coil antennas 21a to 21n function as reader / writer antennas, and are antennas in which a conductor is wound a predetermined number of times in a long and narrow shape along the storage location of the disk case.

  Further, as shown in FIG. 3, LEDs (light emitting diodes) 31a, 31b,..., 31m, 31n as light emitting means are arranged at the front end portion of the bottom plate 22 corresponding to the storage positions of the respective disk cases. It is. The lighting of the LEDs 31a to 31n is controlled according to the storage state of the disk case. The details of the lighting control will be described later. For example, when the disk case is stored in the correct position as shown in FIG. 4, the LED below the storage position is turned on.

  3 and 4 show a configuration in which several disk cases 10 are stored, but in actuality, it is configured as a shelf that can store several tens or hundreds of disk cases 10. Further, FIG. 3 shows a state in which the disk is stored only in the rightmost disk case 10, but the disks are also stored in the other disk cases 10.

Next, the configuration of the reader / writer connected to the storage shelf 20 having the configuration shown in FIGS. 3 and 4 will be described with reference to FIG.
As shown in FIG. 5, the coil antennas 21 a to 21 n arranged on the bottom plate 22 of the storage shelf 20 are connected to a changeover switch 44 and are connected to the reader / writer 42 via the switch 44. The changeover switch 44 is controlled by the antenna control unit 43 based on a command from the management unit 41. For example, under the control of the antenna control unit 43, the changeover switch 44 performs a switching process of selecting and connecting the plurality of coil antennas 21a to 21n in order at predetermined time intervals. For example, when there are 100 coil antennas 21a to 21n, the 100 coil antennas 21a, 21b,... Are sequentially selected and connected to the reader / writer 42, and communication is performed using the connected coil antennas. Do.

The antenna controller 43, the control signal input terminal 52 of the coil antenna 21a to 21n (see FIG. 2), supplies the on-off control signal for the switch _{S 1.} This control signal, the switch S ₁ of the coil antenna in the communication is turned on, a signal to turn off the switch S ₁ of the other coil antenna.

  The reader / writer 42 to which each of the coil antennas 21a to 21n is connected outputs magnetic flux from the connected coil antenna, performs wireless communication with the RFID chip adjacent via the booster antenna 3, and receives data from the RFID chip. And a process for writing data are performed. For reading and writing by the reader / writer 42, a general reader / writer that performs reading and writing by short-range wireless communication is applicable.

The reader / writer 42 is connected to a management unit 41 that manages disks. The management unit 41 and its peripheral processing units include, for example, a personal computer device and its peripheral devices.
The reader / writer 42 sends the data obtained by communication from the RFID chip on the tag sheet 2 side to the management unit 41 and sends the data supplied from the management unit 41 to the RFID chip on the tag sheet 2 side. Send it.
The management unit 41 holds data about disks stored in the storage shelf 20 as a database 48. In addition to the disc code number and the disc related to the content recorded on the disc, the database 48 stores data such as which location on which storage shelf 20 is arranged, and whether or not it is being rented. Is done.

A display 45 is connected to the management unit 41, and the management state can be displayed on the display 45. In addition, an input unit 46 such as a keyboard is provided so that various data can be input.
Furthermore, the lighting control part 47 which controls lighting of LED31a-31n arrange | positioned in the storage shelf 20 is provided, and each LED31a-31n can be lighted separately by the command from the management part 41. FIG. For example, as shown in FIG. 2, it is possible to turn on only a specific LED, for example, 31b corresponding to the position where the disk case 10 is placed.

With the configuration described above, when communicating with the RFID chip, the disk case (disk case 10a in FIG. 1) in which the disk with the RFID chip attached is accommodated and the antenna in communication (FIG. 1). For the coil antenna 21c), the resonance frequency f1 suitable for wireless communication is obtained, and for other antennas, the resonance frequency f2 is different, and the communicating antenna may interfere with other adjacent antennas. Disappear. Therefore, radio communication between the antenna connected to the communication circuit for the reader / writer and the RFID chip can be performed satisfactorily, and communication with the RFID chip attached to a specific one disk can be performed reliably.
As described above, the ability to communicate with a specific single disk side can determine the storage position of the disk, and can effectively manage the disk. That is, it is possible to manage whether or not all the disks placed on the storage shelf match the disks registered in the database, and it is possible to know whether or not the storage position of each disk is correct.

FIG. 6 is a diagram showing another circuit configuration of the coil antenna. In this example, each coil antenna 21a, 21b, as 21c · · ·, providing a parallel circuit of a coil _{L 1} and the capacitor _{C 1,} respectively. Then, the output terminal of the reader-writer 42 is connected to the movable contact of the first changeover switch S _11. The fixed contacts of the first changeover switch _{S 11,} each coil antenna 21a, 21b, connected individually to one end of the parallel circuit of the coil _{L 1} and a capacitor _{C 1} which constitutes the 21c · · ·. The other end of the parallel circuit of the coil L ₁ and the capacitor C ₁ is connected to the ground.
Furthermore, each of the coil antenna 21a, 21b, one end of the parallel circuit of the coil _{L 1} and a capacitor _{C 1} which constitutes the 21c · · ·, connected to the fixed contacts of the second changeover switch _{S 12.} The movable contact of the second changeover switch S12, is connected to the ground via the capacitor C _2.
A first changeover switch S ₁₁ second changeover switch S12, a switch switched in conjunction with the switching of the antenna for communication.

By the configuration shown in FIG. 6, the antenna during communication, along with the reader-writer 42 with the first changeover switch S ₁₁ is connected, a capacitor C ₂ through the second changeover switch S ₁₂ The resonance frequency is determined by the coil L ₁ and the capacitors C ₁ and C ₂ . In contrast, for the other antennas not connected capacitor C2, the resonance frequency is determined by the coil L ₁ and capacitor C _1. Accordingly, the same resonance frequencies f1 and f2 as in the example of FIG. 2 are set, and the same effect as in the example of FIG. 2 is obtained.

  Note that the configurations and processes shown in the respective drawings in the above-described embodiments are only suitable examples, and the present invention is not limited to these configurations and processes. For example, circuit configurations other than those shown in FIGS. 2 and 6 may be used.

  Further, in the present embodiment, as shown in FIG. 7, a sheet with an RFID tag attached is attached in the vicinity of the center of the disk. However, in other configurations, the RFID tag is attached to the disk. You may apply. For example, the present invention may be applied to a disk in which an RFID tag is embedded. Alternatively, the present invention can be applied to a case where an RFID tag is attached to a disk case. Furthermore, the present invention can also be applied to a case where management is performed using a shelf or the like that stores a medium to which an RFID tag other than a disk is attached (embedded).

  In the above-described embodiment, the resonance frequency of all the antennas other than the antenna in communication is changed as the process of changing the resonance frequency of the antenna. In this way, it is preferable to change the resonance frequency of all the antennas other than those in communication, but at least change the resonance frequency of the antenna arranged adjacent to the antenna in communication and do not change the resonance frequency for other antennas. It is good also as a structure.

  DESCRIPTION OF SYMBOLS 1 ... Disk, 1a ... Hole, 2 ... Tag sheet, 2a ... Hole, 2b ... RFID chip, 2c ... Coil antenna, 2d ... Tuning circuit, 3 ... Booster antenna, 3a ... 1st coil antenna, 3b ... Tuning circuit, 3c 2nd coil antenna, 4 ... reader / writer, 4a ... coil antenna, 4b ... tuning circuit, 4c ... main circuit, 10, 10a, 10b ... disc case, 11 ... lower case, 12 ... upper case, 13 ... disc tray , 14 ... Disc mounting part, 15 ... Disc holding mechanism, 16 ... Hole, 17 ... End face, 18 ... Supporting point part, 20 ... Storage shelf, 21a to 21n ... Coil antenna, 22 ... Bottom plate, 23 ... Partition plate, 31a ... 31n ... LED, 41 ... management unit, 42 ... reader / writer, 43 ... antenna control unit, 44 ... changeover switch, 45 ... display, 46 ... input unit, 47 ... Lighting controller, 48 ... database, 51 ... RF input and output terminals, 52 ... control signal input terminal

Claims (3)

In a disk management system for storing and managing a plurality of media or media cases having a contactless wireless tag that performs wireless communication with an antenna connected to a reader / writer,
A plurality of reader / writer antennas arranged corresponding to the respective storage positions where the media or the media case are arranged;
Selecting means for selecting a reader / writer antenna for communication among the plurality of reader / writer antennas;
The reader / writer antenna selected by the selection unit is set to a first resonance frequency corresponding to the frequency for performing the wireless communication, and is arranged adjacent to the reader / writer antenna having at least the first resonance frequency. A media management system, wherein a reader / writer antenna has a second resonance frequency different from the first resonance frequency. The disk management system according to claim 1, wherein
The reader / writer antenna includes a resonance circuit configured by connecting a coil, a first capacitor, and a second capacitor in parallel;
A media management system, wherein the first resonance frequency and the second resonance frequency are switched by switching between connection and non-connection of the second capacitor. Arrange multiple antennas that perform wireless communication with nearby contactless wireless tags,
A selected antenna of the plurality of antennas arranged side by side is connected to a communication circuit to perform wireless communication with the contactless wireless tag and read from the contactless wireless tag and / or to the contactless wireless tag. In the reader / writer that writes
The selected antenna is set as a first resonance frequency for performing the wireless communication,
A reader / writer characterized in that at least an antenna adjacent to the antenna having the first resonance frequency is set to the second resonance frequency.

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