JP4725261B2 - RFID tag inspection method - Google Patents

Description

  The present invention relates to a method for inspecting an RFID (Radio Frequency Identification) tag that is used for communication from a distant location using radio waves in the UHF band, and more specifically, an RFID tag inspection method for accurately inspecting an RFID tag before shipment and The present invention relates to an RFID tag communication method, the device, and the RFID tag.

  In recent years, automation has been promoted in fields such as logistics. In order to promote the automation of this physical distribution, it is important to enable the machine to read information recorded on slips and the like attached to individual articles. As a method for realizing this automation, a bar code label corresponding to the recorded information has been conventionally attached to each slip.

  However, in order to read a bar code label using a bar code reader, the distance between the bar code reader and the bar code label and the direction in which the bar code reader is directed to the bar code label must be associated with high accuracy. The correspondence between the distance and the direction is manually performed each time, so that it takes time, and the barcode reading operation is an obstacle to smooth the physical distribution. Furthermore, since the amount of information that can be input to the barcode is small, the area that can be managed using the barcode label is limited to a narrow area.

  In recent years, RFID tags that can be read in a non-contact manner using an induction electromagnetic field or radio waves have attracted attention. According to this RFID tag, an induction electromagnetic field or radio wave is used as a reading medium, so that distance and direction restrictions are not so much upon reading. For example, an RFID tag using radio waves is not restricted by the directionality of reading, and the recorded information can be reliably read even from a distance of 1M to 5M.

  Here, there are two basic configurations of the RFID tag: an IC chip in which a radio frequency interface unit, a control logic unit, and a storage unit are provided, and an antenna circuit board for transmitting and receiving electromagnetic waves. A typical communication medium uses a UHF band radio wave of 850 to 960 MHz as a communication frequency.

  Usually, when an RFID tag is inspected, an RFID tag is formed by connecting an electronic component such as an IC and an antenna circuit, and then inspected by non-contact communication using radio waves.

  On the other hand, in the RFID tag (see FIG. 1) 80 using the UHF band communication frequency illustrated in FIG. 8, when the reader / writer antenna 81 is associated with the RFID tag 80 arranged in parallel in three rows, Communication is not possible unless the entire RFID tag 80 enters the radio wave region 82 created by the antenna 81. For this reason, when the RFID tag 80 is continuously inspected in the form as shown in FIG. 8, another RFID tag 80 arranged in parallel with the RFID tag 80 to be inspected enters the radio wave region 82, causing interference. This causes a problem that the RFID tag 80 to be inspected cannot be accurately inspected.

  In order to solve such a problem, as disclosed in Patent Document 1, as an example of a method for accurately inspecting a UHF band RFID tag, a shield box (radio wave shielding device) for preventing radio wave diffusion is provided. A method has been proposed in which a communication area is created in a space where radio waves are shielded by this, and only an RFID tag to be inspected is supplied into the space for inspection.

  However, in such a conventional RFID tag inspection method, there is a problem that the inspection apparatus is enlarged in order to provide a shield box, and it is necessary to match the shield box to the outer size of the RFID tag to be inspected. When the RFID tag has a different form and size, there is a problem that the communication inspection cannot be performed with the same device.

JP 2004-272437 A

  The present invention has been made paying attention to the above-described problems. In the method for inspecting the communication state of an RFID tag communicated by radio waves, even if the radio wave shielding device is omitted, only the RFID tag to be inspected is provided. It is an object of the present invention to provide a method and apparatus capable of accurately inspecting or communicating with each other and an RFID tag.

  The present invention relates to an RFID tag inspection method for inspecting an RFID tag including an antenna that communicates at a UHF band communication frequency and a matching circuit that adjusts the impedance of the antenna, and the matching circuit includes an antenna coil of a reader / writer And an RFID tag inspecting method for inspecting the RFID tag by operating a control circuit of the RFID tag with a magnetic flux transmitted from the antenna coil.

  As an aspect of the present invention, the RFID tag can be inspected by setting the size of the antenna coil of the reader / writer to the same size as the matching circuit of the RFID tag.

  Also, as an aspect of the present invention, a plurality of RFID tag matching circuits arranged at regular intervals and a plurality of reader / writer antenna coils arranged at substantially the same arrangement interval as each matching circuit are opposed to each other. Individual pieces can be inspected at the same time.

  The present invention is also an RFID tag inspection apparatus for inspecting an RFID tag comprising an antenna that communicates at a communication frequency in the UHF band and a matching circuit that adjusts the impedance of the antenna. The RFID tag can be inspected by including an antenna coil for transmitting.

  As an aspect of the present invention, the RFID tag can be inspected by forming the size of the antenna coil of the reader / writer in the same size as the matching circuit of the RFID tag.

  Further, as an aspect of the present invention, a plurality of the antenna coils can be arranged side by side, and a plurality of RFID tags facing each antenna coil can be inspected simultaneously.

  The present invention also relates to an RFID tag communication method for communicating with an RFID tag comprising an antenna that communicates at a communication frequency in the UHF band and a matching circuit that adjusts the impedance of the antenna, wherein the matching circuit includes an antenna of a reader / writer. The RFID tag communication method is characterized in that the coils are opposed to each other and the RFID tag control circuit communicates with a magnetic flux transmitted from the antenna coil.

  As an aspect of the present invention, the size of the antenna coil of the reader / writer can be set to the same size as the matching circuit of the RFID tag to communicate with the RFID tag.

  Also, as an aspect of the present invention, a plurality of RFID tag matching circuits arranged at regular intervals and a plurality of reader / writer antenna coils arranged at substantially the same arrangement interval as each matching circuit are opposed to each other. Can communicate simultaneously.

  The present invention also relates to an RFID tag communication device that communicates with an RFID tag comprising an antenna that communicates at a UHF band communication frequency and a matching circuit that adjusts the impedance of the antenna, and a magnetic flux facing the matching circuit. Can be communicated with the RFID tag.

  As an aspect of the present invention, the size of the antenna coil of the reader / writer can be formed to the same size as the matching circuit of the RFID tag to communicate with the RFID tag.

  Further, as an aspect of the present invention, a plurality of the antenna coils are arranged side by side, and can communicate with the RFID tags by simultaneously communicating with a plurality of RFID tags that face each antenna coil one by one.

  Furthermore, as an aspect of the present invention, there is provided an RFID tag used in the RFID tag communication method, in which an antenna structure that communicates in a UHF band is peeled off on a part of the antenna circuit board without destroying the matching circuit. The RFID tag can be configured with a peeling position specifying means for specifying and destroying the position.

  According to the present invention, a stable RFID tag can be inspected with a simple configuration regardless of the shape and size of the RFID tag.

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 shows an RFID (Radio Frequency Identification) tag 11 that uses a UHF band frequency of 850 to 960 MHz. FIG. 1 (A) is a plan view of the RFID tag 11, and FIG. 1 (B) is a front view of the RFID tag 11. The figure is shown. The RFID tag 11 includes an antenna circuit board 12 formed in a rectangular sheet shape and an IC module 13 formed in a rectangular shape sufficiently smaller than the antenna circuit board 12.

  The antenna circuit board 12 is made of PET (polyethylene terephthalate), and a rectangular antenna 14 is provided with a copper antenna 15 that is slightly smaller than the film 14. Each of the film 14 and the antenna 15 is a sheet-like member having a constant thickness and having a softness that can be appropriately bent.

  The antenna 15 is a printed circuit having a substantially square cut-out portion 16 at the center. The upper and lower portions of the cut-through portion 16 are the connection portions 17 and 17 of the IC module 13, and a slit 16a is provided on the left side of the connection portion 17 at the upper portion of the drawing. Further, an insulating layer (not shown) is provided on the upper surface of the antenna 15.

  In the IC module 13, an IC chip (semiconductor bare chip) 19 is mounted between the upper and lower connecting portions 17, 17 of the antenna 15 via a small sheet-like slap 18. The IC chip 19 is a general chip in which a storage unit, a resonance circuit, a rectifier circuit, a voltage detection circuit, a control circuit, and a constant voltage circuit are provided.

  Here, in the hollow portion 16 of the antenna 15, the closed hole 16 b forming an inverted L shape on the right side of the slap 18 is for adjusting the impedance of the entire antenna 15 that communicates with the communication frequency of the UHF band. The matching circuit 20 is formed on the outer peripheral portion surrounding the closing hole 16b, and an antenna coil provided at the same size on the reader / writer side, which will be described later, is paired with the matching circuit 20. Communicate by setting up.

  FIG. 2 shows an inspection method for the RFID tag 11 according to the present invention. The RFID tag 11 is inspected by one to several turns (in the figure, 2 turns) formed almost directly above the matching circuit 20 formed on the antenna 15 of the RFID tag 11 and having the same outer size as the matching circuit 20. (Turn) antenna coil 21 is provided. At this time, the facing distance between the antenna 15 and the matching circuit 20 is set, for example, at a facing distance of about several mm, and the reader / writer 22 supplies the antenna coil 21 with an inspection frequency of 850 to 960 MHz and an output of 10 to 30 dBm. In this inspection method, the magnetic flux 23 is generated in the antenna coil 21 and the matching circuit 20 of the RFID tag 11 is placed in the magnetic field environment for inspection.

  When power from the reader / writer 22 is supplied to the antenna coil 21, the antenna coil 21 emits magnetic flux 23 instead of radio waves, and the transmitted magnetic flux 23 passes through the inside of the matching circuit 20. An induced electromotive force is supplied to the RFID tag 11 to operate the RFID tag 11.

  In this inspection method, the small matching circuit 20 formed on the antenna 15 of the RFID tag 11 is placed in a small magnetic field (magnetic flux 23) generated from the antenna coil 21 of the reader / writer 22, and the RFID tag 11 Inspection becomes possible. For this reason, even if the entire antenna 15 of the flat RFID tag 11 provided for the UHF band is not placed in the radio wave environment of the UHF band, communication with the RFID tag 11 is possible, and in a small magnetic field environment. Inspection becomes possible.

  As a result, since a small magnetic field is used for the inspection of the RFID tag 11 for the UHF band and a wide-area radio wave is not used, it is not necessary to cover the antenna that transmits the radio wave with a radio wave shielding device such as a radio wave shield box. Therefore, even when another RFID tag exists around the RFID tag to be inspected (measured), it is possible to communicate with only one RFID tag to be inspected and may interfere with another RFID tag. There is no.

  The size of the matching circuit 20 of the RFID tag 11 and the size of the antenna coil 21 of the reader / writer 22 are set to be approximately the same size. If the difference in size between the two is large, communication is possible in a small magnetic field environment. This is because sometimes it becomes impossible to match.

  Since the antenna coil 21 for transmitting the magnetic flux 23 is manufactured in accordance with the size of the small matching circuit 20, even if the external size of the antenna 15 of the RFID tag 11 or the shape of the antenna 15 is slightly changed, locally. The matching circuit 20 corresponding to each other has the same structure, so that it can be inspected using the same inspection device without changing the inspection device of the RFID tag 11.

  Since the matching circuit 20 is provided in a substantially square shape, the antenna coil 21 is provided in a square shape corresponding to the cut shape. In this case, the antenna coil 21 is formed in the antenna coil 21 of one turn to several turns, and is provided with the number of turns at which stable generation of the magnetic flux 23 can be obtained. Furthermore, even if the facing distance between the matching circuit 20 and the antenna coil 21 provided on the upper surface of the matching circuit 20 is in contact with each other, the magnetic flux 23 can be similarly transmitted to perform communication.

  The reader / writer 22 is connected to the antenna coil 21 via a matching circuit 24. As shown in the circuit diagram of FIG. 3, the matching circuit 24 includes a variable capacitor C and a variable reactance L. By connecting the matching circuit 24, the power supplied to the antenna coil 21 is kept small.

  FIG. 4 shows an RFID tag roll in which a plurality of RFID tags 11 are arranged at equal intervals on the upper surface of a roll-shaped carrier sheet 25 serving as a base material of the RFID tag 11. An example of an RFID tag inspection apparatus 30 in which the inspection efficiency of the RFID tag 11 is improved by allowing a writer 22a, 22b, and 22c to simultaneously inspect a certain number at a time.

  The RFID tag inspection device 30 is installed at, for example, a terminal portion of a manufacturing line for manufacturing RFID tags, and the RFID tag 11 manufactured by the RFID tag inspection device 30 is in communication with the RFID tag 11 introduced after the manufacturing. Are individually inspected.

  The RFID tag inspection apparatus 30 includes a plurality of reader / writers 22a, 22b, and 22c, a drive unit (not shown) that feeds an RFID tag roll from an end and winds it on a separate core, and a control unit (not shown) that controls these. ) And. The antennas of the reader / writers 22a, 22b, and 22c for transmitting magnetic flux are positioned above the RFID tag 11 mounted on the upper surface of the RFID tag roll on the conveyance path developed between the winding portions of the RFID tag roll. The coils 21a, 21b, and 21c are installed in close proximity to each other. As a result, the RFID tag 11 that has been transported is inspected by communicating under the magnetic field environment of any of the antenna coils 21a, 21b, and 21c that correspond in the transport process.

  Note that it is preferable to provide an output unit that outputs the presence or absence of abnormality in the case of an abnormality in inspection. This output unit can be constituted by, for example, an audio output unit that sounds an alarm sound, or a print output unit that marks an abnormal RFID tag 11 by printing or the like.

  In the collective inspection method corresponding to the RFID tag roll, a plurality of RFIDs are used because a magnetic field environment communicating in a narrow communication area is used instead of a radio wave environment communicating in a wide communication area as described above. The tags 11 can be inspected collectively. For example, the antenna coils 21a, 21b, and 21c of three parallel reader / writers 22a, 22b, and 22c are connected to the corresponding matching circuits 20 of the plurality of RFID tags 11 that are parallel to the upper surface of the carrier sheet 25 at regular intervals. If installed, the three RFIDs 11 can be inspected simultaneously.

  Here, since the antenna coils 21a, 21b, and 21c are arranged and configured at the same interval as the alignment interval of the RFID tags 11 on the carrier sheet 25, the three RFID tags 11 are inspected in one inspection. Can do. For this reason, the control unit (not shown) provided in the RFID tag inspection apparatus 30 can be controlled to advance three steps at a time and inspect the next three again, thereby enabling high-speed inspection.

  In particular, even if the RFID tag 11 is a specification of an RFID tag roll in which the RFID tag 11 is connected at regular intervals, a radio wave shielding device such as a radio wave shield box for separating the RFID tag to be inspected from another RFID tag is not required. The tag inspection device can be miniaturized. In addition, the cost can be reduced by simplifying as the number of parts is reduced.

  FIG. 5 is a side view showing an example of a continuous inspection state of the RFID tag 11 communicating in a magnetic field environment. The facing distance between the RFID tag 11 to be inspected and the antenna coil 21 a that transmits the magnetic flux 23 is set at a slight distance of about A mm (for example, 2 mm), and is not required to be electrically connected. Therefore, even if an insulating layer 26 such as paper or PET is laminated on the surface of the RFID tag 11, the RFID tag 11 can be inspected. In FIG. 4, the antenna coil 21 a is provided on the upper side of the RFID tag 11, but the antenna coil 21 d that transmits the magnetic flux 23 is provided on the lower carrier sheet 25 side that is the base material of the RFID tag 11. However, the RFID tag 11 can be inspected. In any case, since the effective range of the magnetic flux 23 does not reach the RFID tag 11 adjacent to the inspection target, the inspection can be performed one by one reliably.

  By the way, the circuit that receives the magnetic flux 23 from each of the antenna coils 21, 21a, 21b, 21c, and 21d shows the slit 16a as the impedance matching circuit 20, but there are other non-conductive portions for the magnetic flux 23 to escape. Any part of the antenna circuit of the RFID tag 11 may be used as long as the circuit has a certain winding form. However, both ends of the wound circuit need to be connected to the two terminals of the IC chip, respectively.

  For example, as shown in FIG. 6, a winding-type circuit 63 is configured by combining a dipole antenna 61 and a loop antenna 62, and is extended from the reader / writer 22 via the matching circuit 24 on the winding-type circuit 63. The operation of the RFID tag 64 can also be inspected even if the antenna coil 21 thus formed is provided in a pair and the magnetic flux 23 is transmitted from the antenna coil 21 to the circuit 63 having a winding shape.

  FIG. 7 shows an RFID tag 72 provided with a peel seal 71 for destroying an antenna. The RFID tag 72 has an antenna circuit board 12 formed in a rectangular sheet shape like the RFID tag 11 described above, and the antenna circuit board. In addition to the IC module 13 formed in a rectangular shape that is sufficiently smaller than 12, a peel seal 71 is attached to the upper surface of the antenna circuit board 12 on one side of the antenna 15 as shown in FIG. is there. The peel seal 71 is provided on the outer side as seen from the IC module 13 than the adhesive portion 73 formed on the RFID tag 72.

  By providing the peel seal 71, when the peel seal 71 is peeled off, the antenna circuit board 12 integrated with the peel seal 71 is on one side (adhesive portion 73) as shown by an imaginary line in FIG. The outer side of the RFID tag 72 is removed, and the structure of the antenna 15 of the RFID tag 72 can be destroyed.

  Therefore, the RFID tag 72 does not perform the communication function using the radio wave in the UHF band after a part of the antenna circuit board 12 is cut off. For example, the antenna structure can be simply used for the used RFID tag 72. Can be destroyed and discarded. Further, it can be seen that the RFID tag 72 partially peeled off by the peel seal 71 is used at a glance because a part of the antenna 15 is cut off and is in an incomplete state. Further, even if the RFID tag 72 is used, the information recorded in the RFID tag 72 can be obtained by setting the antenna coil 21 of the reader / writer 22 described above to the matching circuit of the RFID tag 72. The information recorded on the RFID tag 72 can be read by allowing communication to be performed below.

  In this case, the adhesive portion 73 between the peel seal 71 and the antenna 15 and the adhesive portion 74 between the antenna circuit board 12 and the IC module 13 are previously crimped by ultrasonic welding or the like when the RFID tag 72 is manufactured. For the peel seal 71, the side close to the IC module 13 is set as an adhesive portion 73 for specifying the peel position. The adhesive portion 73 for specifying the peeling position becomes a crack starting position when the peeling force is applied, and the peeling position of the peeling seal 71 can be specified at a certain point. By specifying the peeling position, a highly reliable destruction operation for the RFID tag 72 can be performed.

  Thus, when the antenna circuit board 12 is peeled off by the peel seal 71, the adhesive portion 73 of the peel seal 71 is peeled off, so that the adhesive portion 74 of the IC module 13 is not peeled off from the antenna circuit board 12. . Further, in order to facilitate peeling, a cut line for peeling may be provided in advance at a position where the antenna circuit board 12 is to be peeled.

  When the RFID tags 11 and 72 are inspected, for example, the communication state of the RFID tags 11 and 72 is inspected in the inspection process before the shipment after the RFID tags 11 and 72 are manufactured.

  In addition, an RFID tag communication device may be formed. The RFID tag communication device may be configured by a reader / writer 22, a communication result output unit, and a control unit that controls these. Execution of communication includes an input unit such as a push switch, for example, and communication is executed by this pressing operation. Alternatively, this signal can be received when the RFID tag 11 periodically transmits a signal.

  The communication result output unit can be a display monitor such as a liquid crystal display, a printer, or a communication device that transmits data, and the communication result is read data read from the RFID tag or written to the RFID tag 11 for writing. It can be data indicating whether or not the loading is successful. This writing can be, for example, writing before shipment of the RFID tag 11. For the identification determination of the inspection, for example, it is preferable to execute a writing inspection for inspecting written information.

  In communication with the RFID tags 11 and 72, when the matching circuit 20 of the RFID tags 11 and 72 is placed in the magnetic field environment of the antenna coil 21, communication for reading and writing information to be communicated to the RFID tags 11 and 72 is performed. The same effect can be obtained even if the RFID tags 11 and 72 are applied for communication purposes.

  As described above, the RFID tag can be inspected by placing a small matching circuit formed in the antenna of the RFID tag in a magnetic field environment. For this reason, since radio waves are not used when inspecting the RFID tag, there is no diffusion of radio waves, there is no interference due to radio waves with another adjacent RFID tag, and the radio wave shielding apparatus can be omitted, and the RFID tag inspection apparatus can be downsized. In addition, since the antenna coil is small, a plurality of antenna coils and a plurality of RFID tags can be associated with each other at the same time. As a result, batch inspection is possible, and inspection efficiency can be improved.

In the correspondence between the configuration of the present invention and the above-described embodiment,
The peeling position specifying means of the present invention corresponds to the peeling seal 71 of the embodiment,
The present invention is not limited to the configuration of the above-described embodiment, and can be applied based on the technical idea described in the claims.

Explanatory drawing of the RFID tag using the communication frequency of a UHF band. The perspective view which shows the test | inspection state of a RFID tag. The schematic block diagram of the matching circuit and antenna coil of a reader / writer. The perspective view which shows the use condition of the RFID tag test | inspection apparatus for RFID tag rolls. Explanatory drawing which shows the test | inspection state from the surface side of a RFID tag, and a back surface side. The perspective view which shows the test | inspection state of the RFID tag of another antenna form. Explanatory drawing which shows the peeling state of the RFID tag provided with the peeling seal. The perspective view which shows the communication state which made the some RFID tag and the antenna of the reader-writer of a UHF band face each other.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11, 64, 72 ... RFID tag 15 ... Antenna 19 ... IC chip 20 ... Matching circuit 21, 21a, 21b, 21c, 21d ... Antenna coil 22, 22a, 22b, 22c ... Reader / writer 23 ... Magnetic flux 30 ... RFID tag inspection apparatus 71 ... peel seal

Claims (13)

An RFID tag inspection method for inspecting an RFID tag comprising an antenna that communicates at a UHF band communication frequency and a matching circuit that adjusts the impedance of the antenna,
An RFID tag inspection method in which an antenna coil of a reader / writer is opposed to the matching circuit, and a control circuit of the RFID tag is operated by a magnetic flux transmitted from the antenna coil to inspect the RFID tag. The RFID tag inspection method according to claim 1, wherein the size of the antenna coil of the reader / writer is set to be approximately the same as the matching circuit of the RFID tag. 2. A plurality of RFID tag matching circuits arranged at regular intervals and a plurality of reader / writer antenna coils arranged at substantially the same arrangement interval as each matching circuit are opposed to each other and simultaneously inspected. Or a method for inspecting an RFID tag according to 2; An RFID tag inspection apparatus that inspects an RFID tag including an antenna that communicates using a UHF band communication frequency and a matching circuit that adjusts the impedance of the antenna,
An RFID tag inspection apparatus including an antenna coil that transmits a magnetic flux facing the matching circuit. The RFID tag inspection apparatus according to claim 4, wherein a size of an antenna coil of the reader / writer is formed to be approximately the same as a matching circuit of the RFID tag. 6. The RFID tag inspection apparatus according to claim 4, wherein a plurality of the antenna coils are arranged side by side, and a plurality of RFID tags facing each antenna coil are inspected simultaneously. An RFID tag communication method for communicating with an RFID tag comprising an antenna that communicates at a UHF band communication frequency and a matching circuit that adjusts the impedance of the antenna,
An RFID tag communication method in which an antenna coil of a reader / writer is opposed to the matching circuit, and communication with the control circuit of the RFID tag is performed by a magnetic flux transmitted from the antenna coil. 8. The RFID tag communication method according to claim 7, wherein a size of the antenna coil of the reader / writer is set to be approximately the same as a matching circuit of the RFID tag. 8. A plurality of RFID tag matching circuits arranged at regular intervals and a plurality of reader / writer antenna coils arranged at substantially the same arrangement interval as each matching circuit are opposed to each other to simultaneously communicate with each other. Or a communication method of the RFID tag according to 8. An RFID tag communication device that communicates with an RFID tag comprising an antenna that communicates at a UHF band communication frequency and a matching circuit that adjusts the impedance of the antenna,
An RFID tag communication device comprising an antenna coil for transmitting a magnetic flux facing the matching circuit. The RFID tag communication device according to claim 10, wherein a size of an antenna coil of the reader / writer is formed to be approximately the same as a matching circuit of the RFID tag. The RFID tag communication device according to claim 10 or 11, wherein a plurality of the antenna coils are arranged side by side, and are configured to communicate simultaneously with a plurality of RFID tags facing each antenna coil one by one. An RFID tag used in claims 7 to 9,
An RFID tag comprising a part of the antenna circuit board including a peeling position specifying means for specifying a peeling position and destroying an antenna structure that communicates in the UHF band without destroying the matching circuit.

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