JP2007241789A - Radio tag reader/writer, communication device and communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the communication between an RFID reader/writer 200 and an RFID tag 700 by devising the antenna 220 of the RFID reader/writer 200. <P>SOLUTION: A radio tag reader/writer includes a second casing 240 accommodating the antenna 200 for communicating with the RFID tag 700, and a first casing 210 accommodating an RFID reader/writer 230 for writing information in the RFID tag 700 or reading information from the RFID tag 700. The angle formed by the antenna 220 and the RFID reader/writer 230 is the angle at which the electric wave sending/receiving surface of the antenna 220 and the sticking surface of the RFID tag 700 are opposite each other, at least during communication with the RFID tag 700. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wireless tag reader / writer, a communication device, and a communication system, and more particularly to a communication device and a communication system having an RFID reader / writer.

  In recent years, an RFID system (Radio Frequency Identification System) has attracted attention. In an RFID system, radio waves are transmitted / received between an RFID tag and an RFID reader / writer to record and read data. Taking advantage of non-contact, RFID systems are used in various fields, including IC card systems such as ticket gate clearing and entrance / exit management, and merchandise logistics (tracking) systems using tags and product tags. ing. In such a case, the portable RFID reader / writer is often used.

  The RFID tag includes a minute IC (integrated circuit) chip that stores data and executes a program, and an antenna for wireless communication. As an RFID tag antenna, a dipole antenna having a simple structure and stable characteristics is often employed.

The dipole antenna has a structure in which two linear conductors are arranged on the same line and a feeding portion is provided between the linear conductors. The radiation directivity of the dipole antenna is a so-called figure 8 in which there is a null (gain drop) in the ± Y direction. Due to the directivity of the dipole antenna, there is an inconvenience in use in that communication between the RFID reader and the RFID tag becomes impossible when the null direction and the RFID reader direction match. In order to solve this problem, a half-wavelength U-shaped dipole antenna has been developed (Non-Patent Document 1).
The Institute of Electronics, Information and Communication Engineers, “Antenna Engineering Handbook”, Ohmsha, October 1980, p. 57

  However, in the half-wavelength U-shaped dipole antenna described in Non-Patent Document 1, the communicable distance between the RFID reader and the RFID tag depends on the direction of the RFID reader and the RFID tag, and the distance is doubled at the maximum. There is a close opening.

  Further, since the RFID tag antenna has restrictions on impedance matching with the IC chip, the degree of freedom of design change is small. For this reason, the half-wavelength U-shaped dipole antenna described in Non-Patent Document 1 has a problem that the communication distance cannot be extended so much. As described above, various improvements to the RFID tag antenna have been attempted, but the decisive effect has not been obtained.

  Therefore, an object of the present invention is to improve the communication between the RFID reader / writer and the RFID tag by devising the antenna of the RFID reader / writer.

In order to solve the above problems, a wireless tag reader / writer according to the present invention includes:
An antenna for communicating with the wireless tag;
A reader / writer that writes information to the wireless tag through the antenna or reads information from the wireless tag;
The angle formed between the antenna and the reader / writer is an angle at which the radio wave transmission / reception surface of the antenna and the attachment surface of the wireless tag face each other at least during communication with the wireless tag.

  As a result, the wireless tag is positioned within the radio wave irradiation area of the antenna during the communication, and thus does not depend on the communication distance between the antenna and the reader / writer and the presence or absence of the directivity of the antenna. In addition, good communication can be performed between the antenna and the reader / writer.

  If the angle between the antenna and the reader / writer is set within a range of 15 degrees to 45 degrees, the radio wave transmission / reception surface of the antenna and the affixing surface of the wireless tag are almost facing each other. I understood.

  The angle formed between the antenna and the reader / writer may be variable. In this way, the angle can be customized by the user, and the reader / writer can be reduced in size when not communicating. In other words, the angle formed between the antenna and the reader / writer may be 0 degrees or 180 degrees when not communicating with the wireless tag.

Further, the communication device of the present invention includes the above wireless tag reader / writer,
A portable terminal that communicates information to be written to or read from the wireless tag with another terminal.

  As a result, it is possible not only to simply write information to or read information from the wireless tag, but also to transmit / receive the information to other terminals.

Furthermore, the communication system of the present invention includes:
The communication device;
And a wireless tag communicated with the communication device.

  This makes it possible to manage the presence of who is where, the distribution management of attaching the tag to the product at the stage of production at the factory, and tracking the movement of the goods through the delivery route, and the history information such as the distribution route of the goods in the goods distribution process. It is possible to accurately perform sensory management such as history management that records information, article management such as managing a large number of books in a library, and data mining.

  In particular, when the wireless tag is set to be sent to the other terminal when the wireless tag is peeled off from the pasting location, the secret in which the customer ledger is stored is stored. This is effective when a wireless tag is attached to the entrance of a room and the entry / exit history of the room is recorded on the wireless tag. That is, typically, when a situation occurs in which the wireless tag is removed in order to conceal the record of unauthorized entry, it is possible to notify other terminals of that fact, It will be possible to stop information leakage.

  Moreover, it is good to provide the spacer which makes this space | interval 5 mm-20 mm between a wireless tag and this sticking object, for example. By doing so, it is possible to connect directly below the peripheral area of the antenna of the wireless tag and form a space immediately below the antenna. The spacer may be a low dielectric constant material (such as a foamed resin having an air content of 50 or more) including a foamed resin, which is provided between the wireless tag and the object to be pasted. That is, the space between the antenna and the object to be pasted is not necessarily a space.

  In particular, in the case of UHF band and SHF band wireless tags, if the wireless tag and its application target are more than a predetermined distance, specifically, if the antenna of the wireless tag and the application object of the wireless tag are more than a predetermined distance, The radio wave from the antenna is not absorbed in the target.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(Embodiment 1)
FIG. 1 is a schematic configuration diagram of a communication apparatus 600 according to the first embodiment of the present invention. FIG. 1 shows a mobile terminal 100 in which an RFID reader / writer 200 is inserted as a communication device 600. As will be described later, the RFID reader / writer 200 is configured so that the antenna portion rotates with respect to the main body portion.

  In the present embodiment, the RFID reader / writer 200 is configured to be insertable / removable with respect to the portable terminal 100. Note that a dedicated device can be used for the mobile terminal 100, and communication and portability such as a PDA (Personal Digital Assistants), a mobile phone (dual type mobile phone with an external slot), and a laptop personal computer are available. It is also possible to use a general-purpose terminal having

  When a PDA, a mobile phone, or the like is used as the mobile terminal 100, the communication device 600 having the following configuration may be used. That is, the RFID reader / writer 200 is a so-called expansion card, and the portable terminal 100 is provided with an expansion slot 110 for connecting the RFID reader / writer 200.

  In the present embodiment, for example, the RFID reader / writer 200 is a compact flash (Compact Flash: hereinafter referred to as “CF”) card, and the expansion slot 110 is a CF slot. Therefore, by inserting the RFID reader / writer 200 into the CF slot 100, the connection between the portable terminal 100 and the RFID reader / writer 200 is realized.

  The mobile terminal 100 is provided with an operation unit 130 having a plurality of input keys and the like. The input key of the operation unit 130 includes an input key for switching on / off the power of the mobile terminal 100, an input key for inputting an instruction to read / write information to / from the RFID tag, and information read from the RFID tag using a communication function. An input key for inputting an instruction to be transmitted to another terminal or the like is included.

  The other terminals include not only other PDAs but also host computers. The type of communication network is not limited, but as an example, an access point or the like is prepared, connected to a host computer or the like via a LAN (Local Area Network), and another PDA via a network such as the Internet. It is conceivable to connect such as.

  In addition, the mobile terminal 100 includes a display unit 120 that displays operation details, operation instructions, investigation results, and the like through the operation unit 130. When the mobile terminal 100 is a PDA or the like, a display unit for displaying contents such as documents and mails is provided, and the display unit 120 may be used as the display unit.

  FIG. 2 is a diagram illustrating a usage example of the communication apparatus 600 illustrated in FIG. 1. FIG. 2 shows a state where the user of the communication device 600 is holding the communication device 600 over the RFID tag 700. Specifically, a usage scene is shown in which the user grips the body of the portable terminal 100 in which the RFID reader / writer 200 is inserted, and manages the presence of the user.

  Here, the RFID reader / writer 200 includes a first housing 230 that accommodates a portion necessary for the reader / writer, and a second housing 240 that accommodates an antenna for wireless communication with the RFID tag 700. Broadly divided. The first casing 230 and the second casing 240 are made of a material that has strength and does not interfere with communication, such as plastic and aluminum. As shown in FIG. 2, in the RFID reader / writer 200, when the communication device 600 is used, the second housing 240 is bent at a required angle θ with respect to the first housing 230. This angle θ is an angle at which the radio wave transmission / reception surface of the antenna portion (second housing 240) of the RFID reader / writer 200 faces substantially parallel to the attachment surface of the RFID tag 700. Specifically, For example, it indicates about 15 to 45 degrees.

  FIG. 3 is a schematic explanatory diagram of the RFID reader / writer 200 shown in FIG. A reader / writer circuit board 210 is accommodated in the first casing 230, and an antenna 220 is accommodated in the second casing 240.

  The first housing 230 and the second housing 240 may be formed by molding or the like so as to be an integrated housing that forms an angle θ, or by adopting a hinge mechanism or the like, the first housing 230 and the second housing 240 It is good also as a structure which can mutually be rotated.

  Moreover, when it is set as the structure which can be rotated, when the communication apparatus 600 is not used, it is good for the 1st housing 230 and the 2nd housing 240 to be in a flat state. This is favorable in terms of portability and compactness of the communication device 600. In such a case, the rotation of the first housing 230 and the second housing 240 may be manually performed by the user prior to use of the communication device 600, or may be performed according to an operation performed by the user through the operation unit 130. Then, it may be performed mechanically or electrically on the RFID reader / writer 200 side.

  Note that since the expansion card type RFID reader / writer 200 is used by being inserted into the expansion slot 110, the thickness of the antenna 220 cannot be obtained. Therefore, by configuring the first casing 230 and the second casing 240 to be rotatable, even if the communication device 600 is accidentally dropped, the stress is relieved at the rotating portion, and the RFID reader / There is an advantage that the writer 200 is not easily damaged. This merit also applies to the RFID reader / writer 200 shown in FIG. 5 described later.

  When the user manually rotates the first housing 230 and the second housing 240, the user has a way of holding the communication device 600, how to hold the communication device 600 to the RFID tag 700, etc. It is preferable that the angle θ can be customized. In this customization, for example, the RFID reader / writer 200 includes a sensor that detects a radio wave state between the RFID tag 700 and a lamp that indicates a detection result of the sensor by lighting or blinking, and the RFID reader / writer The structure 200 can be realized by making the angle between the first housing 230 and the second housing 240 variable in multiple steps, for example, in increments of 5 degrees.

  Thus, prior to actual use of the communication device 600, (1) change of the angle θ, (2) pass the communication device 600 to the RFID tag 700, and (3) confirm the lamp several times. It becomes possible for communication apparatus 600 to determine a desired angle θ. The sensor detection result may be displayed on the display unit 120 without lighting or blinking the lamp.

  Such an angle setting can be performed because of the particularity of the RFID system. In other words, as represented by mobile phones, there are many technologies for visually informing users of the arrival of radio waves, etc., but all of these types of technologies enable users to communicate well. It is not used to make any settings. This kind of technology is usually used only as a guideline to stop making calls on the spot because it is difficult for radio waves to reach, that is, the radio wave conditions are bad.

  On the other hand, when the first housing 230 and the second housing 240 are rotated on the RFID reader / writer 200 side, the RFID reader / writer 200 is subjected to an angular velocity sensor such as a gyro sensor and the output of the sensor. What is necessary is just to provide the motor which act | operates, the drive means etc. which drive a motor according to the output of a sensor. Alternatively, in place of the angular velocity sensor, a sensor that detects a radio wave condition with the RFID tag 700 is provided, and the second casing 240 is rotated in a direction in which the output of the sensor becomes stronger (the radio wave situation is improved). The motor may be driven and controlled.

  The reader / writer circuit board 210 converts a radio signal into a radio wave and transmits it to the RFID tag 700 through the antenna 220, and converts a radio wave transmitted from the RFID tag 700 and received through the antenna 220 into a radio signal. Is installed. Specifically, a memory storing programs necessary for information communication with the RFID tag 700 and communication with other terminals (not shown) and the like, and various programs are executed by executing the programs in the memory. A CPU that performs the above communication and an electronic component such as a resonance circuit are mounted. The antenna 220 is disposed adjacent to the reader / writer circuit board 210. Note that this description does not prevent the second casing 240 from housing other parts than the antenna 220.

  FIG. 4 is a diagram showing a communication state between the communication device 600 and the RFID tag 700 shown in FIG. FIG. 4A shows an example in which the RFID reader / writer 200 has an angle between the first housing 230 and the second housing 240 of 0 degrees. FIG. 4B shows an example in which the RFID reader / writer 200 has the desired angle θ between the first housing 230 and the second housing 240.

  As shown in FIG. 4A, when the angle between the first housing 230 and the second housing 240 is 0 degrees, the center of the second housing 240 is positioned above the center of the RFID tag 700. In this case, the radio wave transmission / reception surface of the RFID reader / writer 200 may not face the application surface of the RFID tag 700. In this case, the RFID tag 700 is not located in the radio wave irradiation area 500 of the antenna 220. To complement this, it is necessary for the user to align the radio wave irradiation area 500 and the RFID tag 700 by positioning the second housing 240 on the right side of FIG. It is difficult to determine how much to shift.

  On the other hand, as shown in FIG. 4B, when the angle between the first housing 230 and the second housing 240 is a desired angle θ, the central portion of the second housing 240 is the central portion of the RFID tag 700. The radio wave transmission / reception surface of the RFID reader / writer 200 faces the application surface of the RFID tag 700. In this case, the RFID tag 700 is located in the radio wave irradiation area 500 of the antenna 220. Therefore, it is not necessary to perform the above alignment.

  Note that the communication method between the RFID reader / writer 200 and the RFID tag 700 is not limited, and either an electromagnetic induction method or a microwave method can be adopted. In other words, the communication frequency band between the RFID reader / writer 200 and the RFID tag 700 is used in a frequency band such as 125 k to 135 kHz band, 13.56 MHz band, 420 to 450 MHz band, 2.45 GHz band, An 800 MHz to 960 MHz band, a 2.45 GHz band, or the like can be employed. The RFID tag 700 may be a passive tag or an active tag.

  However, the RFID reader / writer 200 according to the present embodiment is particularly suitable when a UHF (Ultra-High Frequency) band is employed. This is because the communicable distance between the RFID reader / writer 200 and the RFID tag 700 is shortened if the RFID reader / writer 200 and the RFID tag 700 are not facing each other at the time of communication. This is because the directivity angle is narrower than that of the HF (High Frequency) band, and thus the alignment becomes more difficult.

  In addition, the RFID reader / writer 200 according to the present embodiment is particularly suitable for the type used with the mobile terminal 100. That is, since it is necessary for the portable terminal 100 to suppress battery consumption, the RFID reader / writer 200 can send only a minute output power to the RFID tag 700, so that reception sensitivity is limited. to cause.

  The antenna itself of the RFID reader / writer 200 may be any type, and any of a loop antenna, a dipole antenna, a patch antenna provided with a high dielectric material, and the like may be used. However, the RFID reader / writer 200 can be suitably used when the antenna is of a directional type for the same reason as when using the UHF band radio wave.

  FIG. 5 is a diagram showing a modification of the RFID reader / writer 200 shown in FIG. FIG. 5A shows a state in which the second housing 240 is folded toward the back side of the mobile terminal 100. FIG. 5B shows a state in which the first housing 220 and the second housing 240 are rotated from each other from the state of FIG. FIG. 5C shows a state in which the angle between the first housing 220 and the second housing 240 is set to the angle θ by further rotation from the state of FIG. 5A. Yes.

  By the way, if the RFID reader / writer 200 pays attention to increasing the communicable distance with the RFID tag 700, it is desired to increase the size of the antenna 220 as much as possible in terms of gain. On the other hand, in the mode of use with the portable terminal 100, it is desirable to make the size of the antenna 220 as small as possible in view of portability and smallness.

  Therefore, in this embodiment, as shown in both FIG. 3 and FIG. 5, first, the RFID reader / writer 200 is divided into two cases, a first case 230 and a second case 240. ing. Secondly, the antenna 220 of the RFID reader / writer 200 is increased in size as the mobile terminal 100 is flat with respect to the portable terminal 100.

  Note that the RFID reader / writer 200 shown in FIG. 5 is less portable than the RFID reader / writer 200 shown in FIG. 3 in that the portable terminal 100 does not overhang in the longitudinal direction when not communicating. There is a further merit of small size.

  In the RFID reader / writer 200 shown in FIG. 5, a first housing 230 and a second housing 240 are connected to each other by, for example, a hinge part 250. The hinge part 250 is made of aluminum or plastic. A connection wiring that connects the reader / writer unit 210 and the antenna 220 passes through the hinge unit 250. Further, on the opposite side of the first housing 230 and the second housing 240, the slope portions 230a and 240a are provided so that the angle between the first housing 230 and the second housing 240 can be set to the angle θ. Is formed. Furthermore, the second housing 240 is provided with a buffering portion 260 that relaxes contact with the back surface of the mobile terminal 100 when folded.

(Embodiment 2)
FIG. 6 is a diagram illustrating a usage example of the system using the communication device 600 illustrated in FIG. 1. FIG. 6 shows a communication device 600, an RFID tag 700, an access point 400, a server 800, and a PC 900 described below.

  The communication device 600 may add information for identifying the device 600 to the information from the RFID tag 700 received by the RFID reader / writer 200 and then transmit the information to the access point 400 through the wireless LAN. it can.

  The RFID tag 700 includes an IC in which unique individual information is stored. The RFID tag 700 is activated by radio waves from an external interface connected to the communication device 600, and can transmit individual information to the external interface. The RFID tag 700 is attached to, for example, an office desk. Note that when the RFID tag 700 is peeled off from a desk or the like, it is detected and transmitted to the server 800 side, and subsequent processing such as making it impossible to store solid information of the RFID tag 700 in the server 800 is performed. It is good to give it. Regarding the above-mentioned peeling detection, refer to PCT / JP2005 / 007860, an international application by the present applicant, which is incorporated herein by reference.

  The access point 400 is installed in the office, receives individual information transmitted from the communication device 600 through the wireless LAN, and outputs it to the server 800.

  The server 800 inputs individual information output from the access point 200 and stores it for a certain period. The storage mode of individual information and the like is not limited, but as an example, a table type of information that identifies each communication device 600 and solid information corresponding to each of them is stored as a pair Should be used.

  The PC 900 is for acquiring the position of a specific communication device 600 by accessing the server 800 and outputting information stored in the server 800.

  Note that the RFID tag 700 may be provided in the communication device 600 and the RFID reader / writer 200 may be provided on the desk. Also in this case, the RFID reader / writer 200 is used by bending the second casing 240 so as to form an angle θ with respect to the first casing 230 when the first casing 230 is attached to the top surface of the desk.

  Examples of usage scenes of the system shown in FIG. 6 include the following.

(Usage scene 1)
Each office employee is allowed to have a communication terminal 600. Suppose an employee works at his desk. In this case, the communication terminal 600 possessed by the employee transmits the individual information of the RFID tag attached to the desk to the access point 400 in accordance with a user instruction or periodically. Can do. As a result, the server 800 stores that the communication device 600 possessed by the employee is located in the vicinity of his / her desk.

  In this state, for example, it is assumed that a boss who is present in a separate room or the like wants to know whether the employee is in the office or where the employee is in the office. In this case, the boss may access the server 800 using the PC 900 and refer to information stored in the server 800. As a result, it can be understood that the employee will be present at his / her desk.

  Thereafter, the employee leaves the desk and moves to another desk. In this case, individual information of the RFID tag 700 attached to the other desk can be received and transmitted to the access point 400. As a result, the server 800 stores that the communication device 600 possessed by the employee is located near another desk.

  In this state, suppose that a boss who is present in a separate room or the like wants to know whether the employee is in the office or where in the office the office is. In this case, the boss may access the server 800 using the PC 900 and refer to information stored in the server 800. As a result, it can be understood that the employee will be present at another desk.

  Further, assume that the employee leaves the other desk and moves out of the office. In this case, the communication device 600 possessed by the employee is out of the wireless LAN area. As a result, the solid information corresponding to the information specifying the communication device 600 possessed by the employee in the server 800 is discarded and a blank state is entered. Communication apparatus 600 may stop transmission of a signal addressed to wireless tag 700 on the condition that a beacon signal from access point 400 cannot be received for a predetermined period.

  In this state, suppose that a boss who is present in a separate room or the like wants to know whether the employee is in the office or where in the office the office is. In this case, the boss may access the server 800 using the PC 900 and refer to information stored in the server 800. As a result, it can be understood that the employee will be located outside the office.

  If necessary, in order to reduce leakage of radio waves transmitted from the RFID reader / writer 200, EMI (Electro-Magnetic Interference) measures such as arranging a radio wave absorber around the RFID tag 700 are taken. Good. The high-sensitivity RFID reader / writer 200 is also expected to communicate with the RFID tag 700 several times while the employee is at the desk. When the above communication is performed, a filter may be provided so as not to transmit the position detection signal to the access point 200.

(Usage scene 2)
For example, the server 800 stores confidential data such as customer information and data indicating solid information of the RFID tag 700 attached to a desk installed in a specific room or the like that permits browsing of the confidential data. Keep it. When the RFID tag 700 is removed from the desk, the server 800 is instructed to stop transmitting confidential information.

  In this state, when the communication device 600 is positioned in the vicinity of the desk, the solid information of the RFID tag 700 is transmitted from the communication device 600 to the server 800. Only in this case, confidential data is transmitted from the server 800 to the communication apparatus 600 through the wireless LAN. In this way, confidential data can be viewed only in a specific room, and leakage of confidential data can be prevented.

  Note that confidential data may be placed in a specific room, and a history of communication with the communication device 600 may be left in the RFID tag 700. In such a case, when a situation occurs in which confidential data is taken out of the room, it is possible to support identification of the person taken out by referring to the history in the RFID tag 700.

(Usage scene 3)
It can be suitably used in the fire department. Have firefighters carry the communication device 600. And the RFID tag 700 is affixed on the appropriate place in a fire department. A server 800 and a PC 900 are installed in a management room or the like.

  Here, when dispatching to a fire site, a group composed of a fire engine driver, several fire brigade, etc. is required as a minimum unit. Therefore, when a large-scale fire occurs, identify the number of groups that can be dispatched to the fire site within the fire department, and if the number of groups has not reached the required number, request a support from another nearby fire department, etc. It is necessary to do.

  Under such circumstances, when a fire breaks out, it is necessary to know the number of fire engine drivers and fire fighters who can be dispatched immediately. In this case, it is necessary to immediately obtain the number, position, and the like of fire department members who can request dispatch in the fire department.

  Once the above infrastructure is in place, the number and location of firefighters who can be dispatched within the fire department can be obtained immediately. If you want to call the fire department staff, you can contact the communication device 600, which is a wireless IP phone. You only have to make a call.

  Similar usage modes and effects in this case can also be realized by preparing infrastructure in specific areas such as police stations and factories.

(Embodiment 3)
FIG. 7 is a schematic exploded perspective view of the wireless tag device according to the third embodiment of the present invention. The RFID tag device includes a sheet-coated RFID tag 10, a foamed resin body 20 located on the bottom surface of the RFID tag 10, and an adhesive layer 30 located on the bottom surface of the foamed resin body 20.

  The RFID tag 10 includes an antenna 14 having an antenna length corresponding to a frequency band and an IC chip 12 connected to the antenna 14. Here, the RFID tag 10 is assumed to have a card size. However, for example, the RFID tag 10 may be half or 1/4 of this size. The RFID tag 10 may have a fan shape, a circular shape, or the like.

  The antenna 14 can have, for example, a rectangular loop shape made of a high dielectric resin or a conductive resin, a spiral shape, and an S shape. As an example, when the frequency band is 950 MHz, the antenna length may be 79 mm corresponding to about 0.078875 m which is a quarter wavelength because one wavelength is about 0.315 m.

  The IC chip 12 includes a central processing unit (CPU) and a memory for executing a predetermined program, a transmission / reception circuit that performs transmission / reception via the antenna 14, and a power supply circuit that supplies driving power to the central processing unit and the transmission / reception circuit. Including.

  The foamed resin body 20 has a thickness of 5 mm to 20 mm, for example. As will be described later, when the wireless tag device is affixed to the desk, it is preferable that the wireless tag device be about 10 mm in order to prevent the wireless tag device from being peeled off the desk by applying external force during use. As a result of the experiment, even if the thickness of the foamed resin body 20 exceeded 20 mm, the communication distance with the RFID reader / writer hardly changed. The lower limit of 5 mm is that the RFID tag 10 is separated from the application surface by this extent, typically, the RFID tag 10 is separated from the metal by 5 mm or more, and the radio wave irradiated from the antenna 14 to the application surface side is absorbed. By not being done.

  The foamed resin body 20 preferably has an air content of 50 or more, and more preferably 70 or more. As a result, the dielectric constant of the foamed resin body 20 is lowered, and as a result, radio wave absorption to the metal through the foamed resin body 20 can be suppressed.

  Specifically, as the foamed resin body 20, foamed polystyrene, foamed rubber, or the like can be employed. Note that what is positioned on the bottom surface of the RFID tag 10 only needs to be a low dielectric constant, and sponge, plastic, cardboard, or the like can also be employed. The shape of the foamed resin body 20 is not limited to the rectangular parallelepiped shape shown in FIG. 7, and for example, a lattice-like or honeycomb-like foamed resin column can be adopted.

  Furthermore, in view of suppressing the radio wave absorption to the surrounding metal, typically, the space immediately below the antenna 14 may be a space. Therefore, instead of the foamed resin body 20, it is also possible to arrange a spacer made of an arbitrary material directly under the area other than the area where the RFID tag 10 is formed with the antenna 14 (for example, directly under the edge of the RFID tag 10).

  The pressure-sensitive adhesive layer 30 can employ a double-sided tape, an adhesive, or the like. Also included are pressing and heat welding. The size and shape of the adhesive layer 30 and the foamed resin body 20 may be determined according to the size or shape of the RFID tag 10. Note that these sizes do not necessarily need to match.

  FIG. 8A is a schematic diagram showing a state where the RFID tag device shown in FIG. FIG. 8B is a schematic diagram showing a state where the RFID tag 10 shown in FIG. 7 is attached to the desk 100 without the foamed resin body 20 interposed therebetween. Note that the desk 60 may be made of metal or wooden including a metal beam.

  As shown in FIG. 8A, since the wireless tag device includes the foamed resin body 20, the radio wave 50 from the antenna 14 of the RFID tag 10 is not affected by the desk 60. For this reason, most of the radio waves 50 are emitted toward the surface side of the RFID tag 10.

  On the other hand, as shown in FIG. 8B, when the RFID tag 10 is attached to the desk 100 without the foamed resin body 20, the radio wave 50 from the antenna 14 of the RFID tag 10 is pulled in the direction of the desk 60. For this reason, most of the radio waves 50 are emitted toward the back side of the RFID tag 10.

  In addition, the sticking target of the wireless tag device is not limited to the desk 60, and various things can be considered. In particular, it can be suitably used for objects made of metal. Such objects include mechanical parts such as iron including constant velocity universal joints, rolling bearings, gears and the like. In such a case, the direct deposition of the RFID tag 10 may be performed by coating, injection molding, vacuum pressure bonding, or the like.

  In addition, in each embodiment of this invention, only the content of this invention was illustrated, and unless it deviates from the thought of this invention, it is contained in the claim of this application.

  The present invention can be widely used in the entire communication field.

It is a typical block diagram of the communication apparatus 600 of Embodiment 1 of this invention. It is a figure which shows the usage example of the communication apparatus 600 shown in FIG. FIG. 3 is a schematic explanatory diagram of the RFID reader / writer 200 shown in FIG. 2. FIG. 3 is a diagram illustrating a communication state between the communication device 600 and the RFID tag 700 illustrated in FIG. 2. It is a figure which shows the modification of RFID reader / writer 200 shown in FIG. It is a figure which shows the usage example of the system using the communication apparatus 600 shown in FIG. It is a typical exploded perspective view of the wireless tag device of Embodiment 3 of the present invention. It is a schematic diagram which shows the state which affixed the radio | wireless tag apparatus shown in FIG.

Explanation of symbols

100 portable terminal 110 expansion slot 120 display unit 130 operation unit 200 RFID reader / writer 210 reader / writer circuit board 220 antenna 230 first housing 240 second housing 250 hinge unit 400 access point 600 communication device 700 RFID tag 800 server 900 PC

Claims (8)

An antenna for communicating with the wireless tag;
A reader / writer that writes information to the wireless tag through the antenna or reads information from the wireless tag;
The angle formed by the antenna and the reader / writer is an angle at which the radio wave transmission / reception surface of the antenna and the attachment surface of the wireless tag face each other at least during communication with the wireless tag. lighter.   The wireless tag reader / writer according to claim 1, wherein an angle formed by the antenna and the reader / writer is set within a range of 15 degrees to 45 degrees.   The wireless tag reader / writer according to claim 1 or 2, wherein an angle formed between the antenna and the reader / writer is variable.   4. The wireless tag reader / writer according to claim 1, wherein an angle formed between the antenna and the reader / writer is 0 degree or 180 degrees when not communicating with the wireless tag. 5. A wireless tag reader / writer according to any one of claims 1 to 4,
A communication apparatus comprising: a portable terminal that communicates information to be written to the wireless tag or information to be read from the wireless tag with another terminal. A communication device according to claim 5;
A communication system comprising a wireless tag communicated with the communication device.   The said wireless tag is a communication system of Claim 6 which transmits the signal which shows that to the said other terminal, when it peels from the sticking location.   The communication system according to claim 6, wherein the wireless tag is provided with a spacer that defines a distance between an antenna for wireless connection with the wireless tag reader / writer and a target to which the wireless tag is attached.

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