JP2014041443A - Rfid tag and rfid system - Google Patents

Abstract

An RFID tag is provided that can have a surface on which an antenna is formed as a pasting surface.
A conductive film 501, a dielectric sheet 503, an IC chip 504, a slot antenna 505, and the like are provided. The dielectric sheet 503 is substantially covered with the conductor film 501. The slot antenna 505 has a first slot portion extending in the Y-axis direction and two loop portions connected to both ends of the first slot portion in the Y-axis direction. Each loop part has a rectangular shape. The IC chip 504 is disposed in the first slot portion of the slot antenna 505 and is electrically connected to a portion of the conductor film 501 forming the first slot portion.
[Selection] Figure 14

Description

  The present invention relates to an RFID tag and an RFID system, and more particularly to an RFID tag capable of handling metal and an RFID system including the RFID tag.

  An RFID (Radio Frequency Identification) system is known as one system that transmits information without contact.

  The RFID system generally includes an RFID tag (also referred to as a “wireless tag”) and a reader / writer (RW) device. Information is read from and written to the RFID tag from the RW device by wireless communication.

  The RFID tag includes an RFID tag with a built-in power supply (referred to as an “active tag”) and an RFID tag without a built-in power supply (referred to as a “passive tag”).

  The passive tag uses a radio wave received from the RW device as driving power, operates an integrated circuit such as an integrated IC or LSI, and performs various processes according to the received radio signal (control signal).

  Transmission from the passive tag to the RW device is performed using a reflected wave of the received radio signal. That is, information such as ID information of the tag and the results of the above-described various processes is transmitted on the reflected wave to the RW device.

  Various frequency bands are used in the RFID system, but recently, the UHF band (860 MHz to 960 MHz) has attracted attention. The UHF band is capable of long-distance communication compared to the existing 13.56 MHz band and 2.45 GHz band.

  As the frequency of the UHF band, a frequency around 868 MHz in Europe, 915 MHz in the United States, and 953 MHz in Japan is used.

  The communication distance (communication distance) of the UHF band passive tag is about 3 to 5 m, although it depends on the performance of the integrated circuit built in the tag. Further, the output of the RW device is about 1 watt (W).

  By the way, when a general RFID tag is attached to the surface of a metal object or when moisture exists in the vicinity, communication may be difficult.

  Therefore, various metal-compatible RFID tags that can be attached to the surface of a metal object have been devised (for example, see Patent Documents 1 to 5).

  However, in the conventional RFID tag for metal, it is difficult to use the surface on which the antenna is formed as a pasting surface.

  The present invention is electrically connected to a dielectric sheet, a conductor film in which a slot antenna is formed and substantially surrounding the dielectric sheet, and a portion of the conductor film in which the slot antenna is formed. In the RFID tag including the IC chip, the slot antenna extends in one direction in a plane parallel to the sheet surface of the dielectric sheet, and a linear portion on which the IC chip is disposed, and the linear portion The RFID tag includes two loop portions connected to both ends in one direction.

  In this specification, “electrically connected” means not only when they are in physical contact with each other, but also when they are connected by members having conductivity, and when alternating current can pass. This includes cases where they are close to each other.

  In addition, “substantially surround” means that the passage of alternating current between the conductor film on one surface of the dielectric sheet and the conductor film on the other surface is not hindered. Means.

  According to the RFID tag of the present invention, the surface on which the antenna is formed can be affixed.

It is a figure for demonstrating schematic structure of the RFID system which concerns on one Embodiment of this invention. It is a figure for demonstrating the input device of a portable terminal. It is a figure for demonstrating the relationship (shelf DB) of three shelves and ID numbers, and the relationship (mold DB) of nine metal mold | dies and ID numbers. It is FIG. (1) for demonstrating operation | movement of a RFID system. FIG. 6 is a second diagram for explaining the operation of the RFID system; FIG. 6 is a diagram (part 3) for explaining the operation of the RFID system; FIG. 6 is a diagram (part 4) for explaining the operation of the RFID system; FIG. 6 is a diagram (No. 5) for explaining the operation of the RFID system; FIG. 6 is a diagram (No. 6) for explaining the operation of the RFID system; FIG. 7 is a diagram (No. 7) for explaining the operation of the RFID system; It is FIG. (8) for demonstrating operation | movement of a RFID system. It is FIG. (9) for demonstrating operation | movement of a RFID system. It is FIG. (10) for demonstrating operation | movement of a RFID system. It is FIG. (1) for demonstrating a RFID tag. It is FIG. (2) for demonstrating a RFID tag. It is AA sectional drawing of FIG. It is BB sectional drawing of FIG. It is a figure for demonstrating an IC chip. FIG. 6 is a diagram (part 1) for describing a slot antenna; FIG. 6 is a second diagram for explaining the slot antenna; It is FIG. (1) for demonstrating each dimension of a RFID tag. It is FIG. (2) for demonstrating each dimension of a RFID tag. It is FIG. (1) for demonstrating the junction part of a conductor film. It is FIG. (2) for demonstrating the junction part of a conductor film. It is a figure for demonstrating electrostatic capacitance joining. It is FIG. (1) for demonstrating attachment of an IC chip. It is FIG. (2) for demonstrating attachment of an IC chip. It is a figure for demonstrating the specific example of an RFID tag. It is a figure for demonstrating the affixing state to the metal mold | die of an RFID tag. It is a figure for demonstrating area | region Ma with a strong magnetic field in an RFID tag. It is a figure for demonstrating the modification of an RFID tag. It is AA sectional drawing of FIG. It is a figure for demonstrating the specific example of the RFID tag of a modification. It is a figure for demonstrating the modification 1 of the junction part of a conductor film. It is a figure for demonstrating the modification 2 of the junction part of a conductor film. It is a figure for demonstrating the case of Dy2> Dy1. It is a figure for demonstrating a protection member. It is FIG. (1) for demonstrating addition of a magnet member. It is FIG. (2) for demonstrating addition of a magnet member. It is FIG. (3) for demonstrating addition of a magnet member. It is a figure for demonstrating addition of a reversible thermosensitive recording medium.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a schematic configuration of an RFID system 10 according to an embodiment.

  The RFID system 10 is a system for managing a plurality of molds, and has three shelves (300A, 300B, 300C), a portable terminal 100, a plurality of RFID tags 500, and a plurality of molds (400A to 400I). doing.

  The RFID system 10 corresponds to the UHF band (860 MHz to 960 MHz).

  The plurality of RFID tags 500 are RFID tags having the same configuration, but each stores a unique ID number. Details of the RFID tag 500 will be described later.

  An RFID tag 500 is attached to each of the plurality of molds (400A to 400I) at predetermined positions. In the following, it is assumed that the mold number specifying the mold 400A is 400A, the mold number specifying the mold 400B is 400B,..., And the mold number specifying the mold 400I is 400I.

  Three shelves (300A, 300B, 300C) are shelves for storing molds and are installed in a storage room. An RFID tag 500 is attached to each shelf at a predetermined position. In the following, it is assumed that the shelf number specifying the shelf 300A is 300A, the shelf number specifying the shelf 300B is 300B, and the shelf number specifying the shelf 300C is 300C.

  The portable terminal 100 includes a processing device 101, a storage device 102, an RW device 103, an input device 104, a display device 105, a communication device 106, and the like.

  The processing device 101 includes a CPU, a ROM, a RAM, and the like. The ROM stores a plurality of programs described by codes readable by the CPU, a plurality of data used for executing the programs, and the like. The RAM is a working memory.

  The storage device 102 includes a nonvolatile memory that can retain data even when power is not supplied. The memory stores management information for a plurality of molds (400A to 400I) (hereinafter abbreviated as “mold management information” for convenience). Further, in the memory, the relationship between the three shelves (300A, 300B, 300C) and the ID number recorded on the RFID tag 500, the plurality of molds (400A to 400I), and the RFID tag 500 are recorded. The relationship between the ID number and the relationship between the worker number and the personal identification number for identifying the worker is stored as a database.

  Hereinafter, for convenience, the database including the relationship between the three shelves and the ID number is referred to as “shelf DB”, and the database including the relationship between the plurality of molds and the ID number is referred to as “mold DB”. The database including the relationship between the worker number and the personal identification number is referred to as “worker DB”.

  As the storage device 102, a hard disk device including a hard disk and a driving device for driving the hard disk may be used.

  The RW device 103 reads the ID number of the RFID tag 500 and notifies the processing device 101, and writes information instructed from the processing device 101 to the RFID tag 500. That is, the RW device 103 is a reader / writer device for the RFID tag 500.

  As shown in FIG. 2 as an example, the input device 104 includes an input medium such as a numeric keypad, a direction key, an RFID read key, an RFID write key, and a cancel key, and notifies the CPU of various information input by an operator. .

  The display device 105 includes a display unit such as a liquid crystal display, and displays various information instructed by the CPU.

  The communication device 106 controls bidirectional communication with the server 1000 installed in the management department. Communication between the communication device 106 and the server 1000 may be wireless communication or wired communication.

Next, the operation of the RFID system 10 will be described.
Here, the ID number of the RFID tag 500 attached to the shelf 300A is “3001”, the ID number of the RFID tag 500 attached to the shelf 300B is “3002”, and the RFID tag attached to the shelf 300C. The ID number of 500 is set to “3003” (see FIG. 3). The ID numbers of the RFID tags 500 attached to the molds 400A to 400I are “4001” to “4009”, respectively (see FIG. 3).

  The molds 400A to 400C are stored on the shelf 300A, the molds 400D to 400F are stored on the shelf 300B, and the molds 400G to 400I are stored on the shelf 300C. (See FIG. 1). Therefore, the mold management information shown in FIG. 4 is stored in the memory of the storage device 102.

  The worker turns on the power switch of the mobile terminal 100. At this time, if there is no abnormality after performing a predetermined initialization process, the processing apparatus 101 displays an initial menu on the display unit of the display apparatus 105 as shown in FIG. 5 as an example.

  When the worker selects “shipping process” in the initial menu, the processing apparatus 101 displays, on the display unit of the display apparatus 105, a screen for requesting input of the worker number and the password as shown in FIG. Display.

  When the worker inputs the worker number and the password, the processing device 101 searches the worker DB stored in the memory of the storage device 102, and the relationship between the entered worker number and the password is determined. If it is determined whether it is correct or not, a screen for instructing the input of the mold number of the mold to be delivered is displayed on the display unit of the display device 105 as shown in FIG. 7 as an example. Let Here, as an example, it is assumed that the mold to be delivered is the mold 400D.

  When the worker inputs the mold number (400D in this case) of the mold to be delivered, the processing apparatus 101 refers to the mold management information stored in the memory of the storage device 102, and issues the delivery object. The shelf number (300B in this case) where the mold to be stored is stored is displayed on the display unit of the display device 105.

  When the operator sees the display unit of the display device 105 and recognizes in which shelf the mold to be delivered is stored, the shelf in which the mold to be delivered is stored while holding the portable terminal 100. It moves to a place with a shelf (here, shelf 300B).

  The operator holds the portable terminal 100 so that the RW device 103 faces the mold 400 </ b> D, and presses the “RFID read” key of the input device 104. Accordingly, the RW device 103 reads the ID number (here, “4004”) of the RFID tag 500 attached to the mold 400D and notifies the processing device 101 of the ID number.

The processing apparatus 101 writes the shipping date and the worker number in the RFID tag 500 attached to the mold 400D via the RW apparatus 103. In addition, the processing device 101 records data including the delivery date / time, the worker number, and the die number of the delivery target in the memory of the storage device 102 as the log data of the delivery processing, and also sends a server via the communication device 106. 1000 is notified.
The operator takes out the mold 400D from the shelf 300B and takes it out of the storage room.

  Since the mold 400D is not stored in the shelf 300B, the processing apparatus 101 changes the mold management information stored in the memory of the storage device 102 as shown in FIG. 9 as an example. And the processing apparatus 101 displays an initial menu on the display part of the display apparatus 105, and complete | finishes the leaving process.

  Next, when the worker selects “entry process” in the initial menu, the processing apparatus 101 displays a screen requesting input of the worker number and password of the worker as shown in FIG. 10 as an example. It is displayed on the display unit of the device 105.

  When the worker inputs the worker number and the password, the processing device 101 searches the worker DB stored in the memory of the storage device 102, and the relationship between the entered worker number and the password is determined. If it is determined whether it is correct or not, as shown in FIG. 11 as an example, a message is displayed so as to read the ID number of the RFID tag 500 affixed to the mold to be stored. 105 is displayed on the display unit.

  The worker enters the storage room while holding the mold to be delivered and the portable terminal 100. Here, as an example, it is assumed that the mold to be stored is the mold 400D, and the mold 400D is stored in the shelf 300C.

  The worker places the mold 400D on the shelf 300C, holds the portable terminal 100 so that the RW device 103 faces the mold 400D, and presses the “RFID read” key of the input device 104. Accordingly, the RW device 103 reads the ID number (here, “4004”) of the RFID tag 500 attached to the mold 400D and notifies the processing device 101 of the ID number.

  When the processing apparatus 101 receives the ID number of the RFID tag 500 attached to the warehousing target mold, the processing apparatus 101 is attached to the shelf where the warehousing target mold is stored as shown in FIG. A message is displayed on the display unit of the display device 105 so as to read the ID number of the RFID tag 500.

  The operator holds the portable terminal 100 so that the RW device 103 faces the RFID tag 500 attached to the shelf 300 </ b> C, and presses the “RFID read” key of the input device 104. As a result, the RW device 103 reads the ID number (here, “3003”) of the RFID tag 500 attached to the shelf 300C and notifies the processing device 101 of the ID number.

  The processing apparatus 101 writes data including the date and time of receipt, the worker number, and the shelf number where the mold 400D is received into the RFID tag 500 attached to the mold 400D via the RW apparatus 103. In addition, the processing apparatus 101 records, as log data of the warehousing process, data including the date and time of warehousing, the worker number, the mold number of the warehousing target, and the shelf number in which the mold is received in the memory of the storage device 102. The server 1000 is notified via the communication device 106.

  Since the mold 400D is newly stored in the shelf 300C, the processing apparatus 101 changes the mold management information stored in the memory of the storage device 102 as shown in FIG. 13 as an example. And the processing apparatus 101 displays an initial menu on the display part of the display apparatus 105, and complete | finishes a warehousing process.

  The maintenance process is selected when information registered in the shelf DB, mold DB, and worker DB is changed, added, or deleted.

  By the way, if the “cancel” key is pressed before the processing is completed, the processing device 101 stops the processing, returns to the standby state, and displays the initial menu on the display unit of the display device 105.

Next, details of the RFID tag 500 will be described.
As an example, the RFID tag 500 includes a conductor film 501, a dielectric sheet 503, an IC chip 504, a slot antenna 505, and the like, as shown in FIGS. 16 is a cross-sectional view taken along line AA in FIG. 14, and FIG. 17 is a cross-sectional view taken along line BB in FIG. For convenience of illustration and easy understanding, the thickness and size of each part are exaggerated.

  The dielectric sheet 503 is a quadrangular sheet-like member. Here, for convenience, in the XYZ three-dimensional orthogonal coordinate system, the direction orthogonal to the surface (sheet surface) of the dielectric sheet 503 will be described as the Z-axis direction.

  As a material of the dielectric sheet 503, plastic, ceramic, mica, oil, and water can be used. In addition, when using a liquid as a material of the dielectric material sheet 503, it is used in the state put in the bag made from resin, for example so that a sheet form may be maintained.

  When the material of the dielectric sheet 503 is solid, a plurality of small holes may be formed in at least one of the inside and the surface. For example, the dielectric sheet 503 may be a foam member.

  As a material for the conductor film 501, aluminum, gold, silver, an alloy thereof, or carbon can be used. Here, the conductor film 501 is formed on a film member 502 having a thickness of 5 μm to 250 μm, such as polyester, polyphenylene sulfide, polypropylene, and polyethylene. The film member 502 may be a foamed film member containing air. The conductor film 501 is not formed and used on the film member 502, but the conductor film 501 may be used alone.

  The IC chip 504 includes a microprocessor, a memory (ROM, RAM, EEPROM), a modulator, and the like.

  Here, the IC chip 504 is a label type IC chip that is fixed to a label on which a power feeding terminal is formed, as shown in FIG. 18 as an example.

  Note that the IC chip 504 may be a special chip such as an IC chip whose terminals are so-called capacitively connected or an IC chip having a so-called micro antenna.

  As shown in FIG. 19, the slot antenna 505 extends in the Y-axis direction, and is connected to a first slot portion in which the IC chip 504 is disposed and two ends of the first slot portion in the Y-axis direction. And two loop portions. Each loop part has a rectangular shape.

  The loop portion on the + Y side of the first slot portion includes a second slot portion extending in the −X direction from an end portion on the + Y side of the first slot portion, and an end on the −X side in the second slot portion. A fourth slot portion extending in the + Y direction from the first portion, a sixth slot portion extending in the + X direction from the + Y side end portion of the first slot portion, and a + Y direction from the + X side end portion of the sixth slot portion And an eighth slot portion extending in the direction, and a tenth slot portion connecting the + Y side end portion of the fourth slot portion and the + Y side end portion of the eighth slot portion.

  The loop portion on the −Y side of the first slot portion includes a third slot portion extending in the −X direction from an end portion on the −Y side of the first slot portion, and a −X side in the third slot portion. A fifth slot portion extending in the −Y direction from the end portion of the first slot portion, a seventh slot portion extending in the + X direction from the end portion on the −Y side of the first slot portion, and the + X side in the seventh slot portion A ninth slot portion extending in the −Y direction from the end portion, and an eleventh slot portion connecting the −Y side end portion of the fifth slot portion and the −Y side end portion of the ninth slot portion. It is configured.

  The slot antenna 505 is line-symmetric with a straight line passing through the center of the first slot portion and parallel to the X-axis direction as the axis of symmetry. The slot antenna 505 is line-symmetric with a straight line passing through the center of the first slot portion and parallel to the Y-axis direction as the axis of symmetry.

  Here, as shown in FIG. 20, the width of each slot portion in the slot antenna 505 is s, and the length of the slot antenna 505 in the X-axis direction is 2 × Dxa. Further, regarding the Y-axis direction, the gap between the second slot portion and the third slot portion is Dyc. Hereinafter, this Dyc is also referred to as “center slot length”. Further, the length of the slot antenna 505 in the Y-axis direction is Dyc + 2 × Dyb. Further, Dxa + Dyb is set to a value L indicating the size of the loop portion.

  The slot width s is set within a range of 0.5 mm to 20 mm, and the center slot length Dyc is set within a range of 1 to 20 times the slot width s.

  Further, as shown in FIG. 21, the length (width) in the Y-axis direction of the conductive film 501 on the −Z side of the dielectric sheet 503 is Dy1, and the conductive film 501 on the + Z side of the dielectric sheet 503. The length (width) in the Y-axis direction is Dy2. Here, there is a relationship of Dy2 ≧ Dy1 ≧ Dyc. The length of the dielectric sheet 503 in the Y-axis direction is Dy3, and the length (thickness) of the dielectric sheet 503 in the Z-axis direction is Dz2.

  Further, as shown in FIG. 22, the length of the conductor film 501 in the X-axis direction is Dx2. Since the conductor film 501 is very thin, the length of the dielectric sheet 503 in the X-axis direction is substantially the same as Dx2.

Next, a method for manufacturing the RFID tag 500 will be briefly described.
1. A conductor film 501 is formed on the surface of the film member 502.
As the shape of the film member 502, a tube-shaped film member, one sheet-shaped film member, and a plurality of sheet-shaped film members can be used.
When a plurality of film members are used, the material of each film member may be the same or different.

  The conductor film 501 can be formed on the surface of the film member 502 by vapor deposition, immersion, gravure printing, spray application, or the like of the above material. Alternatively, a metal foil (for example, a thickness of 16 μm) of aluminum, gold, silver, or an alloy thereof may be attached to the surface of the film member 502. Note that the metal foil may be left as it is instead of being attached to the surface of the film member 502.

When the surface resistance of the film member 502 on which the conductor film 501 is formed is measured according to JIS C2316 with a surface resistance meter (ST-3, ST-4) manufactured by Simco Japan, 10 ³ Ω / □ It was the following.

2. An adhesive material or an adhesive is applied to the surface of the film member 502 where the conductor film 501 is not formed.
3. The dielectric sheet 503 is covered with the film member 502 on which the conductor film 501 is formed.
Here, Dy3> Dy2, and the portion of the dielectric sheet 503 excluding the vicinity of both ends in the Y-axis direction is covered with the film member 502 and the conductor film 501.

  In addition, as a method for joining the dielectric sheet 503 and the film member 502, in addition to a method using a general adhesive material or adhesive, (1) a method using a resin adhesive of the same series as the material of the film member 502, ( 2) a method using a resin adhesive and curing agent of the same series as the material of the film member 502, (3) a method of using a resin hot melt adhesive of the same series as the material of the film member 502, and (4) a material of the film member 502. The method using the same series of resin hot melt adhesive and curing agent, (5) a method of dissolving a part of the film member 502, and the like can be used.

  The methods (1), (2), and (4) can increase the bonding force as compared with a method using a general pressure-sensitive adhesive material or adhesive. The methods (3) and (4) can eliminate the need for a solvent. The method (5) can reduce the cost.

  When a single sheet-like film member is used as the shape of the film member 502, the film member 502 is folded along the outer shape of the dielectric sheet 503, and the dielectric sheet 503 is wrapped with the film member 502. Then, both ends in the Y-axis direction of the film member 502 are joined with a conductive adhesive, and silver ink is applied onto the conductor film 501 at the joined portion (see FIG. 23).

  When two sheet-like film members are used as the shape of the film member 502, the dielectric sheet 503 is sandwiched between the two film members 502, and both ends in the X-axis direction are bent along the outer shape of the dielectric sheet 503. . Then, both ends in the Y-axis direction of the film member 502 on the + Z side and both ends in the Y-axis direction of the film member 502 on the −Z side are respectively joined with a conductive adhesive, and a conductor film at each joint portion A silver ink is applied on 501 (see FIG. 24).

  In addition, the said junction part may be joined not only with the adhesive material which has electroconductivity but with a conductive tape, ultrasonic bonding, etc.

  Further, in the above-described joint portion, the conductor film 501 on one side and the conductor film 501 on the other side may be close to each other to the extent that alternating current can pass (see FIG. 25). In this case, the capacitance at the junction is preferably 1 pF to 10 nF. In the following description, a junction that is close enough to allow alternating current to pass through is also referred to as a “capacitive junction” for convenience.

  At this time, for example, a spacer formed of the same material as the dielectric sheet 503 and having irregularities on the surface is disposed between the film member 502 and the dielectric sheet 503, and the gap between the dielectric sheet 503 and the film member 502 is set. A gap may be formed in a part of. As a result, the communication distance can be increased.

4). A slot antenna 505 is formed.
The slot film 505 is formed by punching the + Z side conductor film 501 into a predetermined shape. At this time, only the conductor film 501 may be punched out, or the conductor film 501 may be punched out together with the film member 502. Note that the slot antenna 505 can also be formed by polishing or etching.

  Further, the slot antenna 505 may be formed at the same time in the step of “forming the conductor film 501 on the surface of the film member”.

  For example, when the conductor film 501 is formed by gravure printing, it may be printed with a print pattern that does not print a portion that becomes a slot antenna.

  Further, for example, when the conductor film 501 is formed by vapor deposition, the shape of the slot antenna may be printed with silicon or a fluorine resin before vapor deposition, and the silicon or fluorine resin may be removed after vapor deposition.

Here, the slot antenna 505 will be described.
The value of the length L in the slot antenna 505 is determined from the following equation (1). Here, μs is the relative magnetic permeability of the film member 502, and Es is the relative dielectric constant of the film member 502.

  When the material of the film member 502 is polyvinyl chloride, μs = 1 and Es = 2.3. When the frequency is 920 MHz, the wavelength λ is 0.326 m. Therefore, in this case, the value of L is 0.055 m from the above equation (1). In this case, if the value of L is 0.044 m to 0.066 m, equivalent antenna characteristics can be obtained.

5. IC chip 504 is attached.
The IC chip 504 is attached to the first slot portion at a position where the impedance between the two power supply terminals and the impedance inside the IC chip 504 can be matched. It is ideal that the IC chip 504 is mounted at a position where the impedance matching can be performed. However, if it is difficult to find a position where the impedance matching can be completely performed in the first slot portion, You may attach in the position with few matching shift | offset | difference.

  The IC chip 504 is bonded to the conductor film 501 using an adhesive, an adhesive tape (both sides, one side), an adhesive, ultrasonic welding, and a conductive ink alone or in combination.

  Here, as the IC chip 504, a label type IC chip fixed to a label on which a power supply terminal is formed is used, and the power supply terminal and the conductive film 501 may be bonded with a conductive ink (see FIG. 26). In order to adjust the frequency, the junction between the power supply terminal and the conductor film 501 may be a capacitive junction (see FIG. 27).

  By the way, a conventional RFID tag that does not support metal and has a dipole antenna and an impedance adjustment circuit can be used as a metal-compatible RFID tag. In this case, the impedance adjustment circuit may be cut and the IC chip electrode and the conductor film 501 may be electrically connected.

  In addition, a depression may be formed in the dielectric sheet 503 so that the IC chip 504 is accommodated in the dielectric sheet 503. This recess can be formed by polishing or pressing.

  When the IC chip 504 is attached from the −Z side of the film member 502, the slot antenna 505 is formed prior to the above-mentioned process of “covering the dielectric sheet 503 with the film member 502 on which the conductive film 501 is formed”. However, it is necessary to attach the IC chip 504.

"Concrete example"
As the dielectric sheet 503, vinyl chloride having a thickness of 0.7 mm was used, one adhesive film having a thickness of 45 μm was used as a film member, and an aluminum foil (thickness: 16 μm) was used as the conductor film 501. Then, the RFID sheet 500 was created by sandwiching the dielectric sheet 503 with a film member on which the conductor film 501 was formed. L = 55 mm, s = 1 mm, Dy1 = 50 mm, Dy2 = 50 mm, Dy3 = 54 mm, Dyb = 15 mm, Dyc = 10 mm, Dxa = 40 mm, Dx2 = 80 mm, and Dz2 = 0.7 mm (see FIG. 28).
The RFID tag 500 of this specific example was flexible.

  When the communication performance of the RFID tag 500 of the above specific example was measured with a reader / writer VP750 manufactured by OMRON, communication was possible even at a distance of 1 m. At this time, even when a metal block was placed on the back side of the RFID tag 500, a communication distance of 90% or more when there was no metal block was obtained.

  Further, even when the RFID tag 500 of the specific example was affixed to the cylindrical portion of commercially available can coffee, the communication performance was hardly deteriorated.

  Further, even when the RFID tag 500 of the specific example was attached to the body of an automobile, there was almost no deterioration in communication performance.

  Further, even if the RFID tag 500 of the specific example is attached to the surface of the press die with the surface on the + Z side, that is, the surface on which the slot antenna 505 is provided, being attached (see FIG. 29). There was almost no deterioration in communication performance. In this case, it is not necessary to take measures to protect the IC chip 504. Thus, cost reduction can be achieved. In addition, from the outside, it can be hidden that the RFID tag is attached.

  As a result of various studies on the RFID tag 500, it was found that strong magnetic fields exist in the four regions Ma as shown in FIG. 30 as an example. These strong magnetic fields are considered to generate a large current flow in and around the slot, which is considered to cause radio wave radiation.

  As described above, the RFID tag 500 according to this embodiment includes the conductor film 501, the dielectric sheet 503, the IC chip 504, the slot antenna 505, and the like.

  The conductor film 501 is provided in a region excluding a portion corresponding to the slot antenna 505 on one surface of the film member 502. The dielectric sheet 503 is covered with the film member 502 and substantially covered with the conductor film 501 except for the vicinity of both ends in the Y-axis direction.

  The slot antenna 505 has a first slot portion extending in the Y-axis direction and two loop portions connected to both ends of the first slot portion in the Y-axis direction. Each loop part has a rectangular shape.

  The IC chip 504 is disposed in the first slot portion and is electrically connected to a portion of the conductor film 501 forming the first slot portion.

  In this case, even if the surface on which the slot antenna 505 is formed is used as a pasting surface, an RFID tag that can suppress a decrease in the communication distance can be realized. In addition, it is possible to realize a flexible RFID tag that is compatible with metal and suppresses a decrease in communication distance due to the influence of an object to be attached. And even if the RFID tag 500 is bent, the characteristics hardly deteriorate.

  Therefore, the RFID tag 500 can be stably used at a low price without being limited by the environment in which it is used, the material and shape of the object to be attached, and the shape of the place to be attached.

  The RFID system 10 according to the present embodiment includes the RFID tag 500. Therefore, the RFID system 10 can be used for various purposes without incurring high costs, and can be used with high accuracy and stability. The number or the like can be read, and the reliability of the system can be improved.

  In the above embodiment, as shown in FIGS. 31 and 32, Dy2 = Dy3 may be set. 32 is a cross-sectional view taken along line AA of FIG. A specific example is shown in FIG. Even in this case, it was possible to obtain the same effect as the above embodiment.

  Moreover, in the said embodiment, as FIG. 34 shows as an example, you may coat | cover the junction part of the conductor film 501 with the conductor film 508. FIG. Here, by setting the length Dx1 in the X-axis direction of the conductor film 508 to Dx2 / Dx1 ≧ 1.1, the influence of the metal is further reduced when the RFID tag is attached to the metal. Can do.

  As an example, when the joint portion of the conductor film 501 was covered with the conductor film 508 of Dx1 = 20 mm, the same effect as the above embodiment could be obtained.

  Moreover, in the said embodiment, as FIG. 35 shows as an example, you may overlap the both ends regarding the X-axis direction of the conductor film 501. FIG. Also in this case, by setting the length Dx1 ′ of the overlapping portion of the conductor film 501 to Dx2 / Dx1 ′ ≧ 1.1, the influence of the metal is further reduced when the RFID tag is attached to the metal. Can be made.

  As an example, when the joint portion of the conductor film 501 is covered with the conductor film 508 with Dx1 ′ = 20 mm, the same effect as in the above embodiment can be obtained.

  In the above embodiment, the case of Dy2 = Dy1 has been described. However, the present invention is not limited to this, and Dy2> Dy1 may be used (see FIG. 36).

  Moreover, in the said embodiment, the whole may be covered with the protection member 512 (refer FIG. 37). As the protective member 512, an insulator film having a thickness of 5 μm to 250 μm, such as polyester, polyphenylene sulfide, polypropylene, and polyethylene can be used.

  As an example, the RFID tag 500 of the above specific example was covered with a polyester laminate film. When the communication performance of the RFID tag was measured with a reader / writer VP750 manufactured by OMRON, communication was possible even at a distance of 1 m. At this time, even if the metal block was placed on either the front surface side or the back surface side of the RFID tag, a communication distance equivalent to that when there was no metal block was obtained. Moreover, even when a plurality of metal plates to which the RFID tag is attached are stacked, an ID reading rate of 90% or more can be realized.

  Note that the protection member 512 may cover a part (for example, only one side) of the RFID tag. Even in this case, an ID reading rate of 90% or more could be realized even when a plurality of metal plates attached with the RFID tag were stacked.

  In the above embodiment, as an example, a magnet member 516 may be added between the dielectric sheet 503 and the conductor film 501 as shown in FIGS. 38 and 39. In this case, the RFID tag can be attached to a metal without using an adhesive or an adhesive.

  Moreover, in the said embodiment, as FIG. 40 shows as an example, the magnetic member 516 may be included in the dielectric material sheet 503. FIG. Also in this case, the RFID tag can be attached to a metal without using an adhesive or an adhesive.

  Further, in the RFID tag 500, as shown in FIG. 41 as an example, at least one surface of the dielectric sheet 503 may be covered with a reversible thermosensitive recording medium 517. This reversible thermosensitive recording medium 517 is composed of an adhesive layer, a recording layer, an intermediate layer, a protective layer, and the like (see, for example, JP 2007-245431 A and JP 2003-291533 A). In this case, information can be printed on a portion where the reversible thermosensitive recording medium 517 is exposed (printing area in FIG. 41) using a printing device, and the printed information (printing information) can be rewritten. it can. The print information includes information for specifying a shelf to which the RFID tag is attached (for example, a shelf number), information for specifying a mold to which the RFID tag is attached (for example, a die number), and the like. . Similarly, in the RFID tag 500B and the RFID tag 500D, at least one surface of the dielectric sheet 503 may be covered with a reversible thermosensitive recording medium 517.

The reversible thermosensitive recording medium 517 can be formed on the dielectric sheet 503 using an immersion method, a spray coating method, a laminate, or the like.
In this case, the dielectric sheet 503 itself may be a reversible thermosensitive recording medium.

  In addition, each dimension of the RFID tag 500 in the said embodiment is an example, respectively, It is not limited to them.

  In addition, each dimension in the modified example of the RFID tag is an example, and is not limited thereto.

  Moreover, although the said embodiment demonstrated the case where the shape of the dielectric material sheet 503 was a rectangular sheet form, it is not limited to this. For example, it may be a polygonal sheet with the corners of the rectangle chamfered. In this case, the chamfered portion may be covered with the conductor film 501 or may not be covered.

  In the above embodiment, the case where information is written to the RFID tag 500 has been described. However, the present invention is not limited to this. When information is not written to the RFID tag 500, the IC chip 504 does not require a memory area in which information is written. Further, instead of the RW device 103, a read-only device (reader) that only reads the ID number can be used.

  Moreover, although the said embodiment demonstrated the case where nine metal mold | dies were stored on three shelves, the number of metal mold | dies and the number of shelves are not limited to this.

  In the above embodiment, the case where the RFID system 10 performs mold management has been described. However, the present invention is not limited to this. The present invention can be applied to applications where RFID systems are currently used. And the reliability of a system can be improved.

  Moreover, although the said embodiment demonstrated the case where the frequency was a UHF band, it is not limited to this.

DESCRIPTION OF SYMBOLS 10 ... RFID system 100 ... Mobile terminal (control device) 101 ... Processing device 102 ... Storage device 103 ... RW device (communication device) 104 ... Input device 105 ... Display device 500 ... RFID tag 501 ... Conductor film (first conductor film), 502 ... film member, 503 ... dielectric sheet, 504 ... IC chip, 505 ... slot antenna, 508 ... conductor film, 510 ... conductor film (second conductor) Membrane), 512, protective member (insulator sheet), 516, magnet member, 517, reversible thermosensitive recording medium.

JP 2008-123222 A JP 2009-049655 A JP 2010-218537 A JP 2011-054185 A JP 2011-096056 A

Claims (8)

A dielectric sheet; a conductor film in which a slot antenna is formed and substantially surrounding the dielectric sheet; and an IC chip electrically connected to a portion of the conductor film in which the slot antenna is formed In an RFID tag comprising:
The slot antenna extends in one direction in a plane parallel to the sheet surface of the dielectric sheet, and is connected to a straight line portion on which the IC chip is disposed and to both ends of the straight line portion in the one direction. An RFID tag having two loop portions.   2. The RFID tag according to claim 1, wherein each of the two loop portions has a rectangular shape.   3. The RFID tag according to claim 1, wherein the slot antenna is line-symmetric with a straight line passing through the center of the straight line portion and parallel to a direction orthogonal to the one direction as an axis of symmetry.   The RFID tag according to any one of claims 1 to 3, wherein the slot antenna is line-symmetric with a straight line passing through the center of the straight line portion and parallel to the one direction as an axis of symmetry. .   And an insulating sheet provided on at least one of one side and the other side of the conductive film substantially surrounding the dielectric sheet with respect to a direction orthogonal to the sheet surface of the dielectric sheet. The RFID tag according to any one of claims 1 to 4.   The RFID tag according to claim 1, further comprising a magnet member provided in the dielectric sheet or between the dielectric sheet and the conductive film.   The RFID tag according to claim 1, wherein the dielectric sheet has a display function capable of rewriting display contents at least partially. The RFID tag according to any one of claims 1 to 7, wherein information is stored;
A communication device that reads at least the information by wireless communication with the RFID tag;
And a control device for controlling the communication device.

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