JP2014041444A - Rfid tag and rfid system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an RFID tag that can be used on metal and near water, and can expand a width of a frequency band in which a desired communication range can be obtained.SOLUTION: An RFID tag includes conductor films 501, film members 502, a dielectric sheet 503, an IC chip 504, and a slot antenna. The conductor films 501 are provided in an area on one side surface of the film member 502 excluding a part corresponding to the slot antenna. The dielectric sheet 503 is coated in a multi-layer manner by the film members 502 on which the conductor films 501 are formed excluding in the vicinity of both ends in a Y-axis direction. The slot antenna includes a first slot part extending in a Y-axis direction, and two loop parts connected with both ends in the Y-axis direction of the first slot part. The IC chip 504 is arranged at the first slot part, and is electrically connected with a part of the conductor films 501 forming the first slot part.

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 moisture, 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.

  In the RFID system, various frequency bands are used for communication. 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 the general RFID tag is affixed on 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, the conventional RFID tag for metal / moisture has a limitation on the width of the frequency band where a desired communication distance can be obtained.

  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 dielectric sheet is surrounded by a plurality of the conductive films sandwiching an insulating layer therebetween.

  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, it is possible to increase the width of the frequency band in which a desired communication distance can be obtained in correspondence with metal and moisture.

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 (warehouse DB) of three warehouses and ID numbers, and the relationship (bottle DB) of nine drinking water bottles 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. (11) for demonstrating operation | movement of a RFID system. It is FIG. (12) 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 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 a figure for demonstrating the specific example 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 effect of making the conductor film surrounding a dielectric sheet multilayer. It is a figure for demonstrating the RFID tag 500A of the modification 1. FIG. It is FIG. (1) for demonstrating the communication performance of RFID tag 500A. It is FIG. (2) for demonstrating the communication performance of RFID tag 500A. It is a figure for demonstrating the RFID tag 500B of the modification 2. FIG. It is FIG. (1) for demonstrating the communication performance of RFID tag 500B. It is FIG. (2) for demonstrating the communication performance of RFID tag 500B. 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.

  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 that manages a plurality of drinking water bottles, and includes a management device 1000, three servers (1100A, 1100B, 1100C), a portable terminal 100, a plurality of RFID tags 500, and a plurality of drinking water bottles ( 400A-400I).
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 drinking water bottles (400A to 400I) at predetermined positions. In the following, the bottle number for specifying the drinking water bottle 400A is 400A, the bottle number for specifying the drinking water bottle 400B is 400B,..., The bottle number for specifying the drinking water bottle 400I. 400I.

  The plurality of drinking water bottles (400A to 400I) are stored in three warehouses (300A, 300B, 300C). In each warehouse, an RFID tag 500 is attached at a predetermined position. In the following, it is assumed that the warehouse number for specifying the warehouse 300A is 300A, the warehouse number for specifying the warehouse 300B is 300B, and the warehouse number for specifying the warehouse 300C is 300C.

  Server 1100A is a server for warehouse 300A, server 1100B is a server for warehouse 300B, and server 1100C is a server for warehouse 300C.

  The portable terminal 100 includes a processing device 101, 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 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 receives various information input by an operator from the processing device 101. Notify the CPU.

  The display device 105 includes a display unit such as a liquid crystal display, and displays various information instructed by the CPU of the processing device 101.

  The communication device 106 controls bidirectional communication with the server closest to the three servers (1100A, 1100B, 1100C). The communication between the communication device 106 and the server may be wireless communication or wired communication.

  Each server has a non-volatile memory that can hold data even when power is not supplied. In the memory, the relationship between the three warehouses (300A, 300B, 300C) and the ID number recorded on the RFID tag 500, the plurality of drinking water bottles (400A to 400I), and the ID recorded on the RFID tag 500 The relationship between the number and the relationship between the worker number and the personal identification number for identifying the worker are stored as a database. In addition, management information (hereinafter abbreviated as “bottle management information” for convenience) of a plurality of drinking water bottles (400A to 400I) is stored in the memory.

  Hereinafter, for convenience, a database including the relationship between the three warehouses and the ID number is referred to as “warehouse DB”, and a database including the relationship between the plurality of drinking water bottles and the ID number is referred to as “bottle DB”. The database including the relationship between the worker number and the personal identification number is referred to as “worker DB”.

  The management apparatus 1000 is connected to three servers (1100A, 1100B, 1100C) via a network, and manages a plurality of drinking water bottles (400A to 400I). The management apparatus 1000 also has the bottle management information, the warehouse DB, the bottle DB, and the worker DB.

  A person having a predetermined qualification (authority) changes, adds, and deletes the warehouse DB, the bottle DB, and the worker DB (hereinafter referred to as “change etc.” for convenience) via the management apparatus 1000. be able to. The changed database is immediately sent to three servers (1100A, 1100B, 1100C).

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

  The drinking water bottle 400A to the drinking water bottle 400C are stored in the warehouse 300A, the drinking water bottle 400D to the drinking water bottle 400F are stored in the warehouse 300B, and the drinking water bottle 400G to the drinking water bottle 400I are It is assumed that they are stored in the warehouse 300C (see FIG. 1). Therefore, the bottle management information shown in FIG. 4 is stored in the management device 1000 and the memory of each server.

  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. At this time, the processing apparatus 101 downloads the bottle management information, the warehouse DB, the bottle DB, and the worker DB stored in the memory of the nearest server and stores them in the RAM.

  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 personal identification number, the processing apparatus 101 searches the worker DB stored in the RAM, and determines whether the relationship between the inputted worker number and the personal identification number is correct. When it is determined and determined to be correct, as shown in FIG. 7 as an example, a screen instructing input of the bottle number of the drinking water bottle to be delivered is displayed on the display unit of the display device 105. Here, as an example, it is assumed that the drinking water bottle to be delivered is the drinking water bottle 400C.

  When the worker inputs the bottle number (400C in this case) of the drinking water bottle to be delivered, the processing apparatus 101 refers to the bottle management information stored in the RAM, and the drinking water bottle to be delivered is determined. The stored warehouse number (300A in this case) is displayed on the display unit of the display device 105.

  When the worker sees the display unit of the display device 105 and recognizes that the drinking water bottle to be delivered is stored in the warehouse 300 </ b> A, the worker presses the “confirm” key and holds the portable terminal 100 in the warehouse 300 </ b> A. enter.

  When the “confirm” key is pressed, the processing apparatus 101 displays a message prompting to read (read) the ID number of the RFID tag 500 attached to the drinking water bottle 400C on the display unit 105 (see FIG. 9).

  When the worker finds the drinking water bottle 400 </ b> C, the operator holds the portable terminal 100 so that the RW device 103 faces the drinking water bottle 400 </ b> C, and presses the “RFID read” key of the input device 104. Thereby, the RW device 103 reads the ID number (here, “4003”) of the RFID tag 500 attached to the drinking water bottle 400C and notifies the processing device 101 of the ID number.

  The processing device 101 writes the shipping date and the worker number in the RFID tag 500 attached to the drinking water bottle 400C via the RW device 103. Further, the processing device 101 records data including the date and time of delivery, the worker number, and the drinking water bottle to be delivered in the RAM as log data of the delivery process, and notifies the server 1100A via the communication device 106. .

The processing device 101 displays a message permitting the delivery of the drinking water bottle 400C on the display unit of the display device 105 (see FIG. 10).
The operator takes out the drinking water bottle 400C from the warehouse 300A.

  Since the drinking water bottle 400C is not currently stored in the warehouse 300A, the processing apparatus 101 changes the bottle management information stored in the RAM as shown in FIG. 11 as an example. The processing apparatus 101 notifies the server 1100A of the changed bottle management information.

  The server 1100A notifies the management apparatus 1000 of the changed bottle management information. The management apparatus 1000 notifies the server 1100B and the server 1100C of the changed bottle management information.

  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. 12 as an example. It is displayed on the display unit of the device 105.

  When the worker inputs the worker number and the personal identification number, the processing apparatus 101 searches the worker DB stored in the RAM, and whether or not the relationship between the inputted worker number and the personal identification number is correct. As shown in FIG. 13 as an example, a message is displayed on the display device 105 so as to read the ID number of the RFID tag 500 attached to the drinking water bottle to be received. Display on the screen.

  The worker enters the warehouse to be stocked while holding the drinking water bottle to be delivered and the portable terminal 100. Here, as an example, it is assumed that the potable drinking water bottle is the drinking water bottle 400C, and the drinking water bottle 400C is stored in the warehouse 300B.

  The operator places the drinking water bottle 400C on the shelf of the warehouse 300B, holds the portable terminal 100 so that the RW device 103 faces the drinking water bottle 400C, and presses the “RFID read” key of the input device 104. Thereby, the RW device 103 reads the ID number (here, “4003”) of the RFID tag 500 attached to the drinking water bottle 400C 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 drinking water bottle to be received, as shown in FIG. 14 as an example, the processing apparatus 101 attaches it to the warehouse in which the drinking water bottle to be stored is stored. A message is displayed on the display unit of the display device 105 so as to read the ID number of the attached RFID tag 500.

  The operator holds the portable terminal 100 so that the RW device 103 faces the RFID tag 500 attached to the warehouse 300B, and presses the “RFID read” key of the input device 104. As a result, the RW device 103 reads the ID number (here, “3002”) of the RFID tag 500 attached to the warehouse 300B and notifies the processing device 101 of the ID number.

  The processing device 101 writes data including the date and time of receipt, the worker number, and the warehouse number where the drinking water bottle 400C is received into the RFID tag 500 attached to the drinking water bottle 400C via the RW device 103. Moreover, the processing apparatus 101 records data including the storage date and time, the worker number, the bottle number of the drinking water bottle to be received, and the warehouse number of the warehouse in which the drinking water bottle is received as log data of the warehousing process. At the same time, the server 1100B is notified via the communication device 106.

  Since the drinking water bottle 400C is newly stored in the warehouse 300B, the processing apparatus 101 changes the bottle management information stored in the RAM as shown in FIG. 15 as an example. The processing apparatus 101 notifies the server 1100B of the changed bottle management information.

  The server 1100B notifies the management apparatus 1000 of the changed bottle management information. The management apparatus 1000 notifies the server 1100A and the server 1100C of the changed bottle management information.

  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 warehouse DB, bottle 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. 18 is a cross-sectional view taken along the line AA 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 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 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. 19 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. 20, 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. 21, the width of each slot 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. 22, the length (width) in the Y-axis direction of the conductor film 501 on the −Z side of the dielectric sheet 503 is Dy1, and the conductor 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. 22 is a cross-sectional view taken along the line BB in FIG.

  Further, as shown in FIG. 23, 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.

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 coated in multiple layers with the film member 502 on which the conductive film 501 is formed.

  Here, Dy3> Dy2 is satisfied, and the portion of the dielectric sheet 503 excluding the vicinity of both ends in the Y-axis direction is multilayer-coated 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.

  Here, as the shape of the film member 502, a plurality of sheet-like film members are used. In this case, a plurality of film members 502 on which the conductor film 501 is formed are overlapped to form a laminated body, and the laminated body is bent along the outer shape of the dielectric sheet 503 to wrap the dielectric sheet 503. Then, both ends in the Y-axis direction of the laminate are joined with a conductive adhesive, and silver ink is applied onto the conductor film 501 at the joint.

  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. 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.

4). A slot antenna 505 is formed.
The slot film 505 is formed by punching the conductor film 501 on the + Z side of the dielectric sheet 503 into a predetermined shape together with the film member 502.

  Note that 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.

  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 feeding terminal is formed may be used, and the power feeding terminal and the conductor film 501 may be bonded with a conductive ink. For frequency adjustment, the bonding between the power supply terminal and the conductor film 501 may be capacitive bonding.

  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"
The dielectric sheet 503 is 0.4 mm thick vinyl chloride, the film member 502 is a 45 μm thick adhesive film, and the conductor film 501 is an aluminum foil (thickness 16 μm). Then, the dielectric sheet 503 is tripled by the three film members 502 on which the conductive film 501 is formed. In other words, the conductive film 501 surrounding the dielectric sheet 503 has three layers.

  Further, L = 55 mm, s = 1 mm, Dy1 = 50 mm, Dy2 = 50 mm, Dy3 = 54 mm, Dyb = 15 mm, Dyc = 10 mm, Dxa = 44 mm, Dx2 = 86 mm, and Dz2 = 0.4 mm (see FIG. 24). .

  The RFID tag 500 of this specific example was flexible. Further, when the communication performance of the RFID tag 500 was measured with a reader / writer VP750 manufactured by OMRON, communication was possible even at a distance of 1 m in the frequency band of 860 to 950 MHz. 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 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, the communication performance is deteriorated. There was almost no. 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.

  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.

  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. 25 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.

  Further, the communication performance of the RFID tag was measured with a measuring instrument (tagformance) manufactured by Boyntech Co., Ltd., when the conductive film 501 surrounding the dielectric sheet 503 was one layer and when there were three layers. An example of the measurement result is shown in FIG.

  When the conductive film 501 surrounding the dielectric sheet 503 has three layers, the frequency width at which the measured value at a position 1 m away from the RFID tag is 35 dBm or less is 30 to 30 when the communication frequency is 860 MHz to 950 MHz. The frequency was 50 MHz, which was larger than the case where the conductive film 501 surrounding the dielectric sheet 503 was one layer.

  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 multilayer-coated with a film member 502 on which a conductor film 501 is formed, 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.

  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.

  In this case, it is possible to increase the width of the frequency band where a desired communication distance can be obtained in correspondence with metal and moisture.

  In addition, even if the surface on which the slot antenna 505 is formed is affixed, 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. 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.

  A plurality of modifications of the RFID tag 500 will be described. In the following description, differences from the above embodiment will be mainly described, and the same or equivalent components as those of the RFID tag 500 described above will be denoted by the same reference numerals, and the description thereof will be simplified or omitted. To do.

<< Modification 1 >>
FIG. 27 shows an RFID tag 500A in which a single film member 502 on which a conductor film 501 is formed is continuously wound around a dielectric sheet 503 a plurality of times. Also in this case, the conductor film 501 surrounding the dielectric sheet 503 can be a multilayer.

<< Specific Example of RFID Tag 500A >>
The dielectric sheet 503 is 0.4 mm thick vinyl chloride, the film member 502 is a 45 μm thick adhesive film, and the conductor film 501 is an aluminum foil (thickness 16 μm). Then, the dielectric sheet 503 is tripled by one film member 502 on which the conductor film 501 is formed. In other words, the conductive film 501 surrounding the dielectric sheet 503 has three layers.

  Further, 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 = 86 mm, and Dz2 = 0.4 mm.

  And about the RFID tag 500A of the specific example, the communication performance was measured with the measuring device (tagformance) made from a Boyntec company. An example of the measurement result is shown in FIG.

  In the RFID tag 500A of the specific example, the frequency width at which the measured value at a position 1 m away from the RFID tag is 35 dBm or less is 50 to 70 MHz when the communication frequency is 860 MHz to 950 MHz. Specific example in the above embodiment It was larger than the RFID tag 500.

  Further, the communication performance when the RFID tag 500A of a specific example was attached to a metal was measured with a measuring instrument (tagformance) manufactured by Boyantech. An example of the measurement result is shown in FIG. According to this, even when the RFID tag 500A of the specific example was attached to metal, there was almost no deterioration in communication performance.

<< Modification 2 >>
FIG. 30 shows an RFID tag 500B in which the RFID tag 500A is covered with an insulating sheet 512. As the insulating sheet 512, an insulating film having a thickness of 5 μm to 250 μm, such as polyester, polyphenylene sulfide, polypropylene, and polyethylene, can be used. The insulating sheet 512 can be attached to the RFID tag using an adhesive material or an adhesive.

<< Specific Example of RFID Tag 500B >>
The RFID tag 500A of the above specific example was covered with a polyester laminate film as the insulating sheet 512.

  And about the RFID tag 500B of the specific example, the communication performance was measured with the measuring device (tagformance) made from a Boyntec company. An example of the measurement result is shown in FIG. This measurement result was almost the same as that of the RFID tag 500A of the specific example.

  Further, the communication performance when the RFID tag 500B of the specific example was attached to metal was measured with a measuring instrument (tagformance) manufactured by Boyantech. An example of the measurement result is shown in FIG. According to this, even when the RFID tag 500A of the specific example was attached to metal, there was almost no deterioration in communication performance.

  In the specific example of each RFID tag described above, the case where the conductive film 501 surrounding the dielectric sheet 503 has three layers has been described, but the present invention is not limited to this. In short, it is sufficient that the dielectric sheet 503 is surrounded by the multi-layered conductor film 501.

  By the way, in the said embodiment, as FIG. 33 shows as an example, you may coat | cover the junction part of the conductor film 501 with another 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.

  Moreover, in the said embodiment, as FIG. 34 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.

  Moreover, although the case where Dy2 = Dy1 was demonstrated in the said embodiment, it is not limited to this, Dy2> Dy1 may be sufficient.

  In the above embodiment, another conductor film (referred to as conductor film 510) is added to at least one of the −Z side of the −Z side conductor film 501 and the + Z side of the + Z side conductor film 501. May be.

  Then, using the area S1 of the conductor film 501 obtained by Dx2 × Dy2, the length Dx10 in the X-axis direction of the conductor film 510, and the length Dy10 in the Y-axis direction of the conductor film 510, obtained by Dx10 × Dy10. By setting the relationship with the area S2 of the conductor film 510 to be S2 / S1 ≧ 1.1, the influence of the metal can be further reduced when the RFID tag is attached to the metal.

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

  In the above embodiment, the dielectric sheet 503 may include a magnet member. Also in this case, the RFID tag can be attached to a metal without using an adhesive or an adhesive.

  In the above embodiment, as an example, at least one surface of the dielectric sheet 503 may be covered with a reversible thermosensitive recording medium. This reversible thermosensitive recording medium 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 the exposed part of the reversible thermosensitive recording medium by using a printing apparatus, and the printed information (printing information) can be rewritten. The print information includes information for specifying a warehouse to which the RFID tag is attached (for example, a warehouse number), information for specifying a drinking water bottle to which the RFID tag is attached (for example, a bottle number), and the like. .

  The reversible thermosensitive recording medium can be formed on the dielectric sheet 503 using a dipping method, a spray coating method, a laminate, or the like. The dielectric sheet 503 itself may be a reversible thermosensitive recording medium.

  Moreover, each dimension in the said embodiment is an example, respectively, It is not limited to them.

  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 drinking water bottles were stored in three warehouses, the number of drinking water bottles and the number of warehouses are not limited to this.

  Moreover, although the said embodiment demonstrated the case where the RFID system 10 manages a drinking water bottle, it 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 101 ... Processing device 103 ... RW device (communication device) 104 ... Input device 105 ... Display device 500 ... RFID tag 501 ... Conductor film 502 ... Film member 503 ... Dielectric sheet, 504 ... IC chip, 505 ... Slot antenna, 508 ... Conductor film, 512 ... Insulating sheet, 1000 ... Management device.

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

Claims (10)

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 RFID tag, wherein the dielectric sheet is surrounded by a plurality of the conductive films sandwiching an insulating layer therebetween.   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. The RFID tag according to claim 1, further comprising two loop portions.   The RFID tag according to claim 2, wherein each of the two loop portions has a rectangular shape.   4. The RFID tag according to claim 2, 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 a symmetry axis. 5.   5. 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 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 5.   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 any one of claims 1 to 7, wherein the dielectric sheet has a display function capable of rewriting display contents at least partially. The conductor film substantially surrounding the dielectric sheet is a first conductor film,
With respect to the direction perpendicular to the sheet surface of the dielectric sheet, the dielectric sheet is provided on at least one of the first conductor film on one side of the dielectric sheet and the first conductor film on the other side, and The RFID tag according to any one of claims 1 to 8, further comprising a second conductor film having an area that is one or more times the area of the body sheet. The RFID tag according to any one of claims 1 to 9, wherein information is stored;
A communication device that reads at least the information by wireless communication with the RFID tag;
An RFID system comprising: a management device that manages an object to which the RFID tag is attached based on the information read by the communication device.

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