JP5803289B2 - Non-contact IC label and information identification system - Google Patents

Description

  The present invention relates to a contactless IC label and an information identification system used in the UHF band and the SHF band.

Conventionally, information is exchanged by wireless communication between an RFID tag (non-contact IC label) and a reader (data reader). However, when this RFID tag is attached to a metal adherend, the communication performance deteriorates. To solve this problem, various RFID tag configurations have been studied.
For example, in an electromagnetic induction type RFID tag that uses radio waves in the 13.56 MHz band, a magnetic material (magnetic sheet) having a high magnetic permeability is provided between the antenna and the adherend, and loss is caused between the antenna and the adherend. By securing a route of a small magnetic flux, an RFID tag that can maintain communication performance even when attached to a metal adherend is realized.

  In addition, in radio frequency type RFID tags used in the UHF band and SHF band, a gap between the antenna and the adherend is secured by providing a dielectric or an air layer between the antenna and the adherend. A method of suppressing the influence of the body is generally used, and Patent Document 1 also discloses a configuration in which a magnetic material is provided between the antenna and the adherend.

  Currently, most of the radio frequency RFID tags used in the UHF band and the SHF band operate with linearly polarized waves. For this reason, when reading the ID data of the RFID tag, the distance and speed of data reading differ depending on the angle at which the data reader is approached. Therefore, by adopting a data reader using a patch antenna that operates with circular polarization, the angle dependency during data reading is reduced, reading efficiency is improved, and convenience is improved. .

JP 2005-309811 A

  However, the structure of the above-described patch antenna operating with circular polarization is three-dimensional and expensive. For this reason, it has been difficult to reduce the thickness and reduce the cost of the data reader while maintaining the efficiency of data reading.

  The present invention has been made in view of such problems, and is a non-contact IC label and information identification capable of improving the efficiency of data reading and reducing the thickness and cost of the data reading device. The purpose is to provide a system.

In order to solve the above problems, the present invention employs the following means.
That is, the non-contact IC label according to the present invention includes a magnetic sheet, a plurality of antenna portions disposed on one surface side of the magnetic sheet, and an IC chip connected to the plurality of antenna portions. The contact IC label is characterized in that at least a pair of the plurality of antenna portions operate with circularly polarized waves having the same rotation direction.

  At least a pair of the plurality of antenna portions functions as an array antenna, and circularly polarized radio waves from the respective antenna portions are combined in the air. Since the combined radio waves are also circularly polarized waves having the same rotational direction as the circularly polarized waves from each antenna unit, the radio waves have no directivity, and the angle dependency when reading data is reduced on the non-contact IC label side it can.

  The non-contact IC label according to the present invention includes a first antenna unit and a second antenna unit as the plurality of antenna units, and the first antenna unit and the second antenna unit have the same rotation direction. It is preferable to operate with polarization.

  One circularly polarized radio wave is generated by aerial synthesis from circularly polarized radio waves having the same rotation direction by the first antenna unit and the second antenna unit. Since this radio wave has no directivity, the angle dependency during data reading can be reduced on the non-contact IC label side, and the data reading efficiency can be further improved.

Further, the magnetic sheet has a rectangular shape when viewed in the thickness direction of the magnetic sheet, and the first antenna portion and the second antenna portion are disposed so as to sandwich the IC chip, and The one antenna portion extends only in a direction away from the IC chip in the short direction of the rectangular magnetic sheet from the connection point with the IC chip on one surface side of the magnetic sheet, and In the longitudinal direction of the magnetic sheet, it extends only to one side of the longitudinal direction, and the second antenna part is located on one surface side of the magnetic sheet from the connection point with the IC chip in the lateral direction. It may extend only in a direction away from the IC chip, and may extend only in the other side of the longitudinal direction in the longitudinal direction .

  By arranging the first antenna part and the second antenna part in different directions from the connection location of the IC chip, that is, in a diagonal position on one surface side of the magnetic sheet, the rotation direction is easily made the same. It can be provided to operate with circular polarization. Therefore, one circularly polarized radio wave having no directivity is generated by aerial synthesis, and the angle dependency during data reading can be reliably reduced on the non-contact IC label side, and the efficiency of data reading can be improved.

  In addition, an information identification system according to the present invention includes the above-described non-contact IC label and a data reader that operates by linear polarization and transmits radio waves to the non-contact IC label.

  The non-contact IC label is activated by the radio wave transmitted from the data reader, and the circularly polarized radio wave is returned to the data reader. For this reason, the radio wave returned to the data reader has no directivity, and even if the data reader is operated with linear polarization, the data reading efficiency is not lowered. Therefore, it is possible to reduce the thickness and cost of the data reading device.

  Furthermore, the information identification system according to the present invention may include the above-described non-contact IC label and a data reader that operates by circular polarization and transmits radio waves to the non-contact IC label.

  The non-contact IC label is actuated by the radio wave transmitted from the data reader, and the circularly polarized radio wave is returned to the data reader. For this reason, although the radio wave returned to the data reading apparatus has no directivity, the data reading efficiency can be further improved by using the data reading apparatus that operates with circular polarization. .

  Since the antenna section operates with circular polarization, the angle dependency at the time of data reading on the non-contact IC label side can be reduced, so that the efficiency of data reading can be improved, and the thickness and cost of the data reading device can be reduced. Reduction is possible.

It is a side view which shows typically the information identification system which concerns on embodiment of this invention. It is a top view which shows a non-contact IC label typically, Comprising: (a) is the figure which made arrangement | positioning of the 1st antenna element and the 2nd antenna element the arrangement | positioning A, (b) is the figure made the arrangement | positioning B. is there. It is a side view which shows the structure of a magnetic sheet typically. It is a figure which shows typically the mode of experiment using a non-contact IC label and a data reader. It is a graph which shows the result of the experiment which measured the communication distance between the non-contact IC label and data reader when the thickness of a magnetic sheet is 100 micrometers. It is a graph which shows the result of the experiment which measured the communication distance between the non-contact IC label and data reader when the thickness of a magnetic sheet is 250 micrometers. It is the figure which showed the mode of the electric field in a 1st antenna element and a 2nd antenna element by analysis, Comprising: (a)-(d) shows the time-dependent change of an electric field.

Hereinafter, an information identification system 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 3.
The information identification system 1 includes a non-contact IC label 2 having ID information and a data reader R that reads the ID information. The data reader R transmits radio waves to operate the non-contact IC label 2. Then, the ID information is read by receiving the radio wave returned from the non-contact IC label 2 by the data reader R.

  The data reading device R is a radio wave transmitting / receiving device having a linearly polarized antenna.

  The non-contact IC label 2 includes a magnetic sheet 11 and a communication unit 12 provided on one surface side of the magnetic sheet 11.

The magnetic sheet 11 is a member made of a known material such as a composite material of magnetic particles or magnetic flakes and plastic or rubber, and has a rectangular shape.
Hereinafter, the short direction of the magnetic sheet 11 is referred to as a first direction D, and the longitudinal direction is referred to as a second direction E.

  As shown in FIG. 3, the structure of the magnetic sheet 11 is such that a plurality of thin disk-shaped magnetic alloys overlap each other in the thickness direction of the magnetic sheet 11 (Z direction in FIG. 3). They are arranged in a state facing the first direction D (X direction in FIG. 3) and the second direction E (Y direction in FIG. 3).

  With such a structure, in the magnetic sheet 11, a magnetic flux (magnetic field) is transmitted in the X direction and the Y direction, but transmission of an electric field is small. On the other hand, the transmission of magnetic flux (magnetic field) is small in the Z direction, but the electric field is transmitted. Therefore, the magnetic sheet 11 has anisotropy with respect to an electric field and a magnetic field, that is, the physical property value of the magnetic sheet 11 is determined by two main parameters, a dielectric constant and a magnetic permeability.

  The communication unit 12 transmits and receives radio waves to and from the data reading device R. The outer shape is rectangular and the outer dimension is set smaller than that of the magnetic sheet 11.

  The communication unit 12 includes a base material 13 (not shown), a first antenna unit 14, a second antenna unit 15, and an IC chip 16 that are integrally provided on one surface side of the base material 13. The circuit unit 17 connects the antenna unit 14, the second antenna unit 15, and the IC chip 16. And the one surface side of the magnetic sheet 11 is adhere | attached so that all of these may be covered. At this time, the communication unit 12 is disposed on one surface side of the magnetic sheet 11 so that the centers of the magnetic sheet 11 and the communication unit 12 coincide with each other.

  The base material 13 is a film-like member made of a resin such as PET.

  The first antenna unit 14 transmits and receives radio waves to and from the data reader R, and includes a first connection pad 21 and a first antenna element 23 electrically connected to the first connection pad 21. have.

  The first connection pad 21 is a member having a square shape when viewed from the thickness direction of the magnetic sheet 11, and is provided integrally with the base material 13 by printing silver paste ink on one surface side of the base material 13, Near the center of the base material 13, it is electrically connected to the circuit portion 17.

  Further, as shown in FIG. 2A, the first antenna element 23 is electrically connected to the first connection pad 21 so as to be continuous with the first connection pad 21. When viewed from the other surface side of the base material 13, the first antenna element 23 has one side D1 in the first direction D1 (upper side in FIG. 2) and one side E1 in the second direction E1 (in FIG. 2). It is a member made of an aluminum thin film or the like having a rectangular shape extending toward the left side.

  Similar to the first antenna unit 14, the second antenna unit 15 transmits and receives radio waves to and from the data reading device, and includes a second connection pad 22 and a second antenna element 24. And the 2nd connection pad 22 is a member which makes square shape seeing from the thickness direction of the magnetic sheet 11, and is integrated with the base material 13 by printing silver paste ink on the one surface side of the base material 13. It is provided and is electrically connected to the circuit portion 17 in the vicinity of the center of the base material 13.

  The second antenna element 24 is electrically connected to the second connection pad 22 so as to be continuous with the second connection pad 22, and when viewed from the other surface side of the base material 13, the second direction D 2 ( This is a member made of a thin aluminum film or the like having a rectangular shape extending toward the other side E2 in the second direction (the lower side in FIG. 2) and the other side E2 in the second direction (the right side in FIG. 2).

  Therefore, the first antenna part 14 and the second antenna part 15 are arranged at diagonal positions with the circuit part 17 sandwiched between one surface side of the base material 13.

  FIG. 2B shows a case where the extending directions of the first antenna element 23 and the second antenna element 24 are opposite to those in FIG. That is, when viewed from the other surface side of the base material 13, the first antenna element 23 is located near the center of the base material 13 in the first direction one side D <b> 1 (upper side in FIG. 2) and in the second direction other side. The second antenna element 24 extends from the vicinity of the center of the base member 13 in the first direction D2 (the lower side of the drawing in FIG. 2), and the second antenna element 24. It extends toward the direction one side E1 (left side in FIG. 2).

  Here, the arrangement of the first antenna element 23 and the second antenna element 24 illustrated in FIG. 2A is referred to as “arrangement A”, and the arrangement illustrated in FIG. 2B is referred to as “arrangement B”.

  The IC chip 16 is disposed on one surface side of the base material 13 and supplies radio wave energy from an electrical contact (not shown) by a radio wave system so that stored information can be transmitted from the electrical contact to the outside. It is a known electronic component to be transmitted as. In addition, the IC chip 16 is connected to the first connection pad 21 and the second connection pad 22, that is, the first antenna unit 14 and the second antenna unit 15 through the circuit unit 17 electrically connected to the electrical contact. It is connected.

  The circuit portion 17 is formed by wiring meandering into a predetermined shape, and its outer shape has a substantially rectangular shape with the first direction D as the short direction and the second direction E as the long direction. Yes.

  The circuit unit 17 is an impedance matching circuit configured by an inductance value and a resistance value for matching the internal impedance of the IC chip 16 with the antenna impedances of the first antenna unit 14 and the second antenna unit 15. Yes. And this circuit part 17 is arrange | positioned so that it may be pinched | interposed into the 1st direction D by the 1st antenna part 14 and the 2nd antenna part 15, and in the edge part of the 2nd direction one side E1 of the circuit part 17 The IC chip 16 is electrically connected to an electrical contact (not shown).

  Furthermore, like the first connection pad 21 and the second connection pad 22, the circuit unit 17 is provided integrally with the base material 13 by printing silver paste ink on one surface side of the base material 13. .

  According to the information identification system 1 as described above, the first antenna unit 14, the second antenna unit 15, and the circuit unit 17 are formed by printing the silver paste ink on the base material 13 of the non-contact IC label 2. A so-called thin dipole antenna structure is formed. In addition, by providing the magnetic sheet 11, it is possible to read and receive information from the IC chip 16 by transmitting and receiving radio waves to and from the data reader R.

  Here, in the case of the arrangement A, the current transmitted from the first connection pad 21 to the first antenna element 23 is a circularly polarized wave that rotates counterclockwise when viewed from one side of the magnetic sheet 11, that is, It propagates in the first antenna element 23 as a left-handed circularly polarized wave. Similarly, a left-handed circularly polarized wave propagates in the second antenna element 24.

  On the other hand, in the case of the arrangement B, the current transmitted from the first connection pad 21 to the first antenna element 23 is a circularly polarized wave that rotates clockwise when viewed from one surface side of the magnetic sheet 11, that is, right A circularly polarized wave is propagated through the first antenna element 23. Similarly, right-handed circularly polarized waves propagate in the second antenna element 24.

  Note that the circularly polarized wave is a combination of vertically polarized waves and horizontally polarized waves that are 90 ° out of phase, and propagates while the plane of polarization rotates.

  Here, the rotation direction of the circularly polarized wave is a connection portion between the circuit portion 17 and the first antenna portion 14 and the second antenna portion 15, that is, a position where the first connection pad 21 and the second connection pad 22 are arranged. This is determined by the extending directions of the first antenna element 23 and the second antenna element 24 as the base points.

  As described above, the circularly polarized waves generated in the first antenna unit 14 and the second antenna unit 15 are the first antenna unit 14 and the second antenna unit 15 function as an array antenna, and the circularly polarized waves from each of them are combined in the air. Is done. This synthesized circularly polarized wave also becomes a circularly polarized radio wave having the same rotation direction as each circularly polarized wave. Therefore, this radio wave has no directivity, and the non-contact IC label 2 side does not have any directivity when reading data. Angle dependency can be reduced.

  In the information identification system 1 according to the present embodiment, the non-contact IC label 2 operating with circular polarization can reduce the angle dependency at the time of data reading on the non-contact IC label 2 side. Therefore, it is possible to improve the data reading efficiency, and it is possible to use a data reader R that does not employ a patch antenna and operates with a linearly polarized wave, thereby reducing the thickness and reducing the cost of the data reader R. it can.

  Further, when the first antenna unit 14 and the second antenna unit 15 are in the arrangement A, the current is left-handed circularly polarized wave. Therefore, by using the data reading device R that operates with left-handed circularly polarized wave. Data reading efficiency can be further improved. On the other hand, in the case of the arrangement B, further improvement in data reading efficiency can be achieved by using a device that operates by right-handed circular polarization.

The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to the present embodiment, and includes changes in the configuration without departing from the gist of the present invention. .
For example, in the present embodiment, the first connection pad 21, the second connection pad 22, and the circuit unit 17 are integrally provided on the base material 13 by printing silver paste ink on the base material 13. Or you may form these in the base-material 13 surface by etching thin films, such as copper.

  The shapes of the first antenna element 23 and the second antenna element 24 are not limited to those of the present embodiment. For example, when viewed from the thickness direction of the magnetic sheet 11, a circular shape, an elliptical shape, a polygonal shape, and the like. You may have done. Further, the shapes of the first antenna element 23 and the second antenna element 24 may be different from each other.

And the 1st antenna part 14 and the 2nd antenna part 15 should just be arrange | positioned in the mutually different direction of the 1st direction D or the 2nd direction E, and are not limited to arrangement | positioning of this embodiment. Specifically, it is possible to arrange the circuit unit 17 so as to be sandwiched from the first direction D or the second direction E.
Further, the present invention is not limited to providing the first antenna unit 14 and the second antenna unit 15, and a plurality of antenna units may be provided. In this case, it is necessary to provide a plurality of antenna units so that at least a pair of antenna units operate with circularly polarized waves having the same rotation direction.

  A resin member or an air layer may be provided between the magnetic sheet 11 and the first antenna unit 14 and the second antenna unit 15.

  When the non-contact IC label 2 is actually used, information such as characters and figures for visual or machine reading may be described on the substrate 13. Further, a film or paper on which such information is described may be provided on the base material 13, or such information may be described by a printer or the like.

  Here, an experiment for confirming the circular polarization characteristics of the first antenna element 23 and the second antenna element 24 was performed. Hereinafter, a description will be given with reference to FIGS.

(Experiment)
The equipment and materials shown below were used for the experiment.
Magnetic sheet 11: NRC010 (thickness 100 μm) and NRC025 (thickness 250 μm) manufactured by Daido Steel Co., Ltd.
IC chip 16: UCODE G2iL made by NXP
First antenna element 23, second antenna element 24: aluminum thin film having a thickness of 12 μm Base material 13: PET film having a thickness of 50 μm Circuit portion 17, first connection pad 21, second connection pad 22: made in-house . Print pattern on substrate 13 with silver paste ink (thickness 8μm)
Data reader R1: 950 MHz band RFID reader / writer, manufactured by Mitsubishi Electric Corporation, RF-RW002 (maximum output 1W 30 dBm)
Read antenna A: 950 MHz band RFID antenna RF-ATCP001 (left-handed circularly polarized wave maximum gain 6 dBi) manufactured by Mitsubishi Electric Corporation
Fixed attenuator T: Hirose Electric AT-103 (Attenuation 3 dB)
-Metal plate W: Made of stainless steel (250 mm x 250 mm x 0.5 mm)

(Create sample)
The magnetic sheet 11 has a length in the first direction D (hereinafter simply referred to as “width”) of 45 mm, and a length in the second direction E (hereinafter simply referred to as “length”) of 125 mm. And two types of thicknesses of 100 μm and 250 μm. The first antenna element 23 and the second antenna element 24 have a width of 5 mm, 10 mm (only when the thickness of the magnetic sheet 11 is 100 μm) and 15 mm, and three stages, and a length of 20 mm, 30 mm, and 40 mm, and three stages. Changed to. That is, a total of nine types of first antenna elements 23 and second antenna elements 24 were used.
The first connection pad 21 and the second connection pad 22 have a square shape with a side of 5 mm, and the distance between the first connection pad 21 and the second connection pad 22 in the first direction D is 6 mm.

(Experimental procedure)
As shown in FIG. 4, on the stainless steel metal plate W, the magnetic sheet 11 having any one of the above thicknesses was disposed. Then, similarly to the position shown in FIG. 2 on the magnetic sheet 11, the first antenna element 23 and the second antenna element 24 of any of the above sizes are arranged, and the circuit portion 17 and the first connection are further provided thereon. The pads 21 and the second connection pads 22 were arranged by printing on one surface of the substrate 13. At this time, the first antenna element 23 is arranged to be electrically connected to the first connection pad 21, and the second antenna element 24 is arranged to be electrically connected to the second connection pad 22.

  A foamed polystyrene (not shown) is placed on the other surface side of the substrate 13, and the first antenna element 23 and the first connection pad 21, and the second antenna element 24 and the second connection pad 22 are provided. The metal plate W to the foamed polystyrene were collectively fixed with a band so as to be securely connected.

Then, the reading antenna was approached from the polystyrene foam side, and the ID information stored in the IC chip 16 was read by the radio wave method. And the maximum value (communication distance) of the distance which the reading antenna A can read information from the communication part 12 in non-contact was calculated | required.
In addition, it is known that the polystyrene foam and the base material 13 hardly affect the measurement result of the communication distance.

  When the measurement of one specification is finished, the band is removed, the first antenna element 23 and the second antenna element 24 sandwiched between the magnetic sheet 11 and the base material 13 are removed, and the first antennas having different size specifications are removed. The element 23 and the second antenna element 24 were sandwiched between the magnetic sheet 11 and the base material 13 and fixed with a band, and measurement was performed.

  In each of the arrangements A and B of the first antenna element 23 and the second antenna element 24 shown in FIG. 2, the widths of the first antenna element 23 and the second antenna element 24 are 5 mm and 10 mm (the thickness of the magnetic sheet 11). (Only when the thickness is 100 μm) and three steps of 15 mm, the length is changed to three steps of 20 mm, 30 mm and 40 mm, and the thickness of the magnetic sheet 11 is changed to two steps of 100 μm and 250 μm, and the measurement of the communication distance is repeated. .

The data reader R1 and the reading antenna A used in the experiment are a UHF band high-power reader / writer and antenna suitable for reading the non-contact IC label 2 of the present invention.
Although the maximum output of the data reader R1 is 1 W (30 dBm), a -3 dB fixed attenuator T is connected to the coaxial cable connecting the data reader R1 and the reading antenna A for the convenience of the experimental environment. The experiment was performed with the output of R1 attenuated to 0.5 W (27 dBm).
Note that the reading antenna A used in the experiment is a patch antenna that operates by left-handed circular polarization.

  Here, if the object to be read is operating with left-handed circular polarization or right-handed circular polarization, there should be a difference in communication distance depending on the arrangement A and arrangement B of the first antenna element 23 and the second antenna element 24. is there. That is, when the communication distance is extended in the left-handed circularly polarized wave arrangement A and the communication distance is lowered in the right-handed circularly polarized wave arrangement B, the communication distance from the reading antenna A is increased in the arrangement A with the longer communication distance. It is inferred that it is operating with left-handed circular polarization. On the contrary, it is presumed that in the arrangement B where the communication distance has decreased, it operates with right-handed circular polarization as viewed from the reading antenna A. The circular polarization characteristics of the first antenna element 23 and the second antenna element were confirmed by such a method and concept.

(result)
FIG. 5 shows the experimental results when the thickness of the magnetic sheet 11 is 100 μm.
As shown in FIG. 5A, the thickness of the magnetic sheet 11 is as thin as 100 μm, and the length of the first antenna element 23 and the second antenna element 24 in the first direction D (hereinafter simply referred to as “antenna width”). The value of communication distance is generally low because it is the smallest 5 mm. The difference in communication distance regarding the arrangement of the first antenna element 23 and the second antenna element 24 is the length in the second direction of the first antenna element 23 and the second antenna element 24 (hereinafter simply referred to as “antenna length”). ) Is 20 mm, there is a difference between the arrangement A and the arrangement B, but the difference between the arrangement A and the arrangement B is small for other antenna lengths.

  FIG. 5B shows the experimental results when the antenna width is 10 mm, and the communication distance is the same for all antenna lengths. In addition, the communication distance is longer for arrangement A than arrangement B for all antenna lengths, and the disparity is wider than when the antenna width is 5 mm.

  FIG. 5C shows experimental results when the antenna width is 15 mm, which is the widest. Compared to the case where the antenna width is 10 mm, all antennas in both arrangement A and arrangement B except for the antenna length of arrangement B and 20 mm. The communication distance is long and the disparity between the arrangement A and the arrangement B is clear for all antenna lengths.

Next, FIG. 6 shows the experimental results when the thickness of the magnetic sheet 11 is 250 μm.
FIG. 6A shows the experimental results when the antenna width is 5 mm, and the arrangement A has a significantly increased communication distance compared to the result when the thickness of the magnetic sheet 11 is 100 μm at all antenna lengths. I understand. On the other hand, in the arrangement B, there is little increase in the communication distance, and the disparity between the arrangement A and the arrangement B is clear for all antenna lengths.

  FIG. 6B shows the experimental results when the antenna width is 15 mm, which is the widest, and the arrangement A has a significantly longer communication distance than the result of the magnetic sheet 11 having a thickness of 100 μm at all antenna lengths. I understand that. Similarly, the communication distance of the arrangement B is increased, and the difference between the arrangement A and the arrangement B is clear at all antenna lengths.

  As described above, it can be confirmed that the communication distance is increased by increasing the antenna length, the antenna width, and the thickness of the magnetic sheet 11. However, when compared under the same experimental conditions, the arrangement A is more preferable than the arrangement B. It was confirmed that the communication distance has increased compared to

  From the above experimental results, it can be said that the first antenna element 23 and the second antenna element 24 are operating in a left-handed circularly polarized wave as viewed from the reading antenna A. On the other hand, it can be said that the first antenna element 23 and the second antenna element 24 in the arrangement B having a low communication distance operate with right-handed circular polarization as viewed from the reading antenna A.

  Note that in a general RFID tag of a half-wavelength dipole antenna type (non-contact IC label) operating in the air by the action of an electric field, the antenna length of the antenna element is dominant in the influence on the communication distance. It is generally known that the antenna width of an element has only an effect of widening its band. In contrast to this trend, it was confirmed that the effect of the experiment on the communication distance was greatly affected by the antenna width, and that the communication distance could be improved by widening the antenna width.

  Then, the electrical property values (permeability, magnetic loss, dielectric constant, dielectric loss, etc.) of the magnetic sheet 11 are made suitable, the impedance of the circuit unit 17, the thickness of the magnetic sheet 11, the first antenna It is assumed that the communication distance can be further improved by optimizing the sizes of the element 23 and the second antenna element 24.

  Furthermore, if the thickness of the magnetic sheet 10 is 100 μm or more and the antenna widths of the first antenna element 23 and the second antenna element 24 are each 5 mm or more, the communication distance is significantly reduced even if the antenna length is reduced. Therefore, the non-contact IC label 2 can be downsized in the second direction E while maintaining a certain communication distance. This miniaturization can reduce the manufacturing cost of the non-contact IC label 2.

Conversely, by increasing the antenna length of the first antenna element 23 and the second antenna element 24, the communication distance can be improved to some extent. Further, as described above, by changing the electrical property values (magnetic permeability, magnetic loss, dielectric constant, dielectric loss, etc.) of the magnetic sheet 11, the antenna length can be further increased (40 mm or more, etc.) for further communication. There is also the possibility of obtaining distance. That is, it is inferred that antenna length≈communication distance.
As described above, the thickness of the magnetic sheet 11, the antenna widths of the first antenna element 23 and the second antenna element 24, and the antenna length can be designed according to the target communication distance.

Next, in FIG. 7, in order to confirm the state of the electric field in the first antenna element 23 and the second antenna element 24, the non-contact IC label 2 is analyzed by a three-dimensional electromagnetic field simulator (HFSS manufactured by ANSOFT). The results will be described.
7 is a view of the communication unit 12 as viewed from the other surface side of the magnetic sheet 11 in the thickness direction of the magnetic sheet 11, and in actuality, the arrangement A shown in FIG. Same arrangement.

  In addition, the analysis model used in this analysis shows the antenna widths of the first antenna element 23 and the second antenna element 24 in order to make it easier to see the state of the electric field on the surfaces of the first antenna element 23 and the second antenna element 24. It is large and slightly different from that described in the embodiment.

From the analysis results, it can be confirmed that each of the first antenna element 23 and the second antenna element 24 rotates clockwise around a position slightly deviated from the center. That is, it turns out that it is a right-handed circular polarization in this analysis.
In the analysis, since it is a right-handed circularly polarized wave as viewed in the thickness direction of the magnetic sheet 11 from the other surface side of the magnetic sheet 11, when viewed in the same manner as in FIG. It is.

  Although not shown in the figure, when the arrangement of the circuit unit 17 and the first antenna element 23 and the second antenna element 24 is the arrangement B, it can be confirmed that the rotation direction of the circularly polarized wave is reverse. It was.

DESCRIPTION OF SYMBOLS 1 ... Information identification system, 2 ... Non-contact IC label, 11 ... Magnetic sheet, 12 ... Communication part, 13 ... Base material, 14 ... 1st antenna part, 15 ... 2nd antenna part, 16 ... IC chip, 17 ... Circuit , 21 ... connection pad, 22 ... second connection pad, 23 ... first antenna element, 24 ... second antenna element, D ... first direction, E ... second direction, D1 ... one direction in the first direction , D2 ... the other side in the first direction, E1 ... one side in the second direction, E2 ... the other side in the second direction, R ... the data reading device, R1 ... the data reading device, W ... the metal plate, A ... the reading antenna, T ... Fixed attenuator

Claims (3)

A magnetic sheet;
A plurality of antenna portions arranged on one side of the magnetic sheet;
In a non-contact IC label comprising an IC chip connected to the plurality of antenna units,
As the plurality of antenna units, a first antenna unit and a second antenna unit,
The first antenna unit and the second antenna unit operate by circular polarization with the same rotation direction,
The magnetic sheet has a rectangular shape when viewed in the thickness direction of the magnetic sheet,
The first antenna part and the second antenna part are arranged so as to sandwich the IC chip,
The first antenna portion extends on one surface side of the magnetic sheet only from the connection position with the IC chip in a direction away from the IC chip in the short direction of the rectangular magnetic sheet. In the longitudinal direction of the magnetic sheet, it extends only to one side of the longitudinal direction,
The second antenna portion extends only in a direction away from the IC chip in the lateral direction from the connection point with the IC chip on one surface side of the magnetic sheet, and in the longitudinal direction. non-contact IC label characterized by extending only the other side of the longitudinal direction. A non-contact IC label according to claim 1 ;
An information identification system comprising: a data reader that operates by linearly polarized waves and transmits radio waves to the non-contact IC label. The non-contact IC label according to any one of claims 1 to 2 ,
An information identification system comprising: a data reader that operates by circular polarization and transmits radio waves to the non-contact IC label.