JP2015056075A - RFID sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an RFID sheet which does not cause a hindrance to an RFID inlay.SOLUTION: An RFID sheet includes an RFID inlay and a sheet base material in which a maximum value of compressive stress Pe of the RFID inlay received from the sheet base material does not exceed a stress threshold value Pd of the RFID inlay when the RFID inlay is installed on the sheet base material so that a surface step generated between the RFID inlay and the sheet base material is within a predetermined range.

Description

  Embodiments described herein relate generally to an RFID sheet in which an RFID inlay is attached to a sheet-like member.

  An RFID sheet in which a so-called RFID (RADIO FREQUENCY IDENTIFICATION) inlay is sandwiched between inner layers of printing paper has been proposed. An RFID sheet in which an RFID inlay is incorporated can associate printed display contents with information to be written on the IC chip of the sandwiched RFID inlay, and various conveniences are considered as printing paper.

  On the other hand, in the RFID inlay, an RFID IC chip is mounted on an antenna member formed thin by aluminum vapor deposition or the like, and the IC chip protrudes from the surface. For this reason, if a protrusion or a step is generated on the surface of the RFID sheet due to the protrusion of the IC chip of the RFID inlay or the antenna member, printing spots may occur when printing is performed, or a paper jam may occur inside the printing press. It is done.

  Therefore, a recess that can accommodate an IC chip is provided in advance in the sheet base of the RFID sheet, and the RFID inlay is aligned and bonded to the sheet base so that the IC chip is placed in the recess, thereby flattening the RFID sheet. Things are known.

  However, in such a technique, there is a restriction that the RFID inlay cannot be disposed at a position other than the recessed portion provided in advance. For this reason, there is an inconvenience that the contents to be displayed are less flexible in an application in which the printed content applied to the RFID sheet is associated with the stored content of the RFID inlay. In addition, if a recess is provided at each position of the sheet base material in accordance with the use and format of the RFID sheet, there is a problem that it is difficult to reduce the manufacturing cost from the viewpoint of mass production efficiency.

  Also, if an RFID inlay is attached to a position other than the recess provided on the sheet base material, an excessive force is applied to the RFID inlay, resulting in poor contact between the IC chip and the antenna member, or a soft sheet base. There is a problem that a material is used and a so-called waistless RFID sheet is formed.

JP 2006-53833 A

  The problem to be solved by the embodiments of the present invention is to provide an RFID sheet that can flatten the surface without impairing the degree of freedom of the printing content and the position where the RFID inlay is installed.

  The RFID sheet of one embodiment has an RFID inlay received from a sheet substrate when the RFID inlay is attached to the sheet substrate so that a surface step generated between the RFID inlay and the sheet substrate is within a predetermined range. The maximum value of the compressive stress Pe is configured using an RFID inlay and a sheet base material that satisfy a relationship that does not exceed the stress limit value Pd of the RFID inlay.

Sectional drawing which shows the RFID sheet | seat of one Embodiment. Sectional drawing which shows the structural member of the RFID sheet. Sectional drawing which shows the state which pressed the RFID inlay against the sheet | seat base material of the RFID sheet | seat. The graph which shows the relationship between the distortion of a sheet base material, and compressive stress. The front view which shows a compressor.

  FIG. 1 is a cross-sectional view showing a completed state after stacking RFID sheets 10 according to an embodiment of the present invention. FIG. 2 is an exploded cross-sectional view showing the laminated structure of the RFID sheet 10 for each constituent member. FIG. 3 is a cross-sectional view showing a state in which the RFID inlay 12 is pressed against the sheet base material 14. FIG. 4 is a graph showing their relationship with the distortion rate E of the sheet base material 14 as the horizontal axis and the compressive stress Pe as the vertical axis. FIG. 5 is a front view showing the pressure tester 110 that compresses the sheet base material 14.

First Embodiment As shown in FIG. 1, an RFID sheet 10 is, for example, water resistant paper for a laser printer, an RFID inlay 12, a sheet base material 14 to which the RFID inlay 12 is attached, and a surface to be attached to the sheet base material 14. A thin material 16 and a back surface thin material 18 are provided. The RFID sheet 10 is used for the purpose of collating menus and important documents, for example.

  Hereinafter, regarding the RFID sheet 10, the surface of the sheet base material 14 on which the RFID inlay 12 is attached is defined as the front surface (representative surface) of the RFID sheet 10, and the opposite surface is defined as the back surface of the RFID sheet 10. The side of the RFID sheet 10 is determined based on the above. Further, the direction from the periphery of the RFID sheet 10 toward the center is defined as inward, and the opposite is defined as outward.

  The RFID inlay 12 includes an antenna member 22 of a dipole antenna thinly formed by vapor deposition of aluminum or copper, and an RFID IC chip 24 connected to a power feeding portion of the antenna member 22, all of which are made of a resin film. 26 is covered. The connection terminal of the IC chip 24 is in contact with the power feeding portion of the antenna member 22 and is electrically connected.

  The IC chip 24 includes a memory, a communication circuit, a control circuit, and a connection terminal, and is connected to a power feeding unit provided at the center of the antenna member 22 via the connection terminal. The RFID inlay 12 receives power supply and information from an external device in a contactless manner, and sends information to the external device.

  FIG. 3 shows a state in which the sheet base material 14 and the RFID inlay 12 are viewed from the side. As shown in FIG. 3, the RFID inlay 12 has a shape in which an IC chip 24 protrudes from a flat antenna member 22. The RFID inlay 12 has a maximum height width H1 from the antenna member 22 to the tip of the IC chip 24 (including the resin film 26).

  As shown in FIG. 3, the RFID inlay 12 is attached to the surface of the sheet base material 14 with the IC chip 24 facing the sheet base material 14 side. When the IC chip 24 enters the sheet substrate 14, a pressing force is generated on the sheet substrate 14. In the structure of the RFID inlay 12, the connecting portion between the IC chip 24 and the antenna member 22 is most easily broken, and the stress limit value Pd when the RFID inlay 12 is pressed from the front and back is P1.

  Next, a method for measuring the stress limit value Pd of the RFID inlay 12 will be described with reference to FIG. First, an RFID inlay 12 is stacked on a sheet substrate 100 of a semi-rigid material whose relationship between compressive stress and strain rate is known, and an IC chip 24 faces the sheet substrate 100, and a sheet substrate on which the RFID inlay 12 is stacked. The material 14 is placed on the pressure tester 110.

  The head 112 of the pressure tester 110 is gradually lowered to bury the RFID inlay 12 in the sheet base material 14 as shown in FIG. Further, the unique code of the RFID inlay 12 is continuously read by the RFID reader antenna 114 and the reader device 116 installed in the immediate vicinity of the RFID inlay 12.

  The reader device 116 acquires the distortion rate E of the sheet base material 100 at the time when the unique code from the RFID inlay 12 becomes unreadable from the position of the head 112 of the pressure tester 110 at that time. The distortion rate E is defined as a percentage of how much the sheet base material 100 is compressed to a thickness before pressing.

  Next, the compression stress Pe corresponding to the strain rate E at the time when the unique code cannot be read is obtained from the known compressive stress versus strain rate characteristic of the sheet base material 100 as shown in FIG. To do. Thereby, the stress limit value Pd of the RFID inlay 12 is obtained. When the compressive stress versus strain rate characteristic of the sheet base material 100 is not known, the stress limit value Pd of the RFID inlay 12 is obtained by using a measurement value of a stress measuring machine or the like included in the pressure tester 110. .

  The sheet base material 14 is formed of a material having a predetermined hardness K1 having a thickness width of W1. The hardness K1 of the sheet base material 14 is the hardness of a semi-rigid material, that is, between a hard material and a soft material. The maximum height width H1 of the RFID inlay 12 is substantially equal to a value of about 50% of the thickness width W1 of the sheet base material 14. The sheet base material 14 is deformed along the shape of the thickness of the RFID inlay 12, and the deformed sheet base material 14 generates a compressive stress in accordance with the strain rate E as shown in FIG.

  FIG. 4 shows the relationship between the compressive stress Pe and the strain rate E of the sheet base material 14. In the graph of FIG. 4, the horizontal axis represents the strain rate E, and the vertical axis represents the compressive stress Pe. The sheet base material 14 has an inflection point S at which the inclination of the compressive stress Pe changes greatly when pushed in gradually from the surface. The inflection point S of the sheet base material 14 is a state where the sheet base material 14 is compressed to 70%.

  That is, when the sheet base material 14 is compressed and the strain rate E increases, the compressive stress Pe gradually increases, and the compressive stress Pe rapidly increases beyond the inflection point S. From the graph, the compressive stress when the sheet base material 14 is compressed by 50% is P2. P2 is a value smaller than P1, which is the stress limit value of the RFID inlay 12.

  If the hardness of the sheet base material is K2 and the hard material has compressive stress versus strain rate characteristics as shown in FIG. 4, the compressive stress Pe at the point of 50% strain becomes P5, and the RFID inlay P1 that is a stress limit value of 12 is exceeded.

  As the sheet base material 14, for example, a so-called low density paper having a cushion paper density of 0.6 g / cm 3 or less may be used. When the paper thickness of the sheet substrate 14 is 200 μm and the basis weight is 100 g / m 2, the density is 0.5 g / cm 3 by dividing the basis weight by the paper thickness. On the other hand, if the density is too low, there will be more space between the paper fibers, and even if the surface is coated with PET film, the paper will not be rigid enough or flatness will be reduced, making it suitable for applications such as copying and printing. There may not be. Therefore, the lower limit of the density is desirably about 0.3 g / cm 3.

  In the RFID sheet 10, the RFID inlay 12 is disposed at a desired position of the above-described sheet base material 14 so that the convex portion by the IC chip 24 faces the sheet base material 14 side, and the surface is pressed as shown in FIG. Then, the RFID inlay 12 is buried in the sheet base material 14. When the surfaces of the RFID inlay 12 and the sheet base material 14 are formed to have a predetermined level difference, for example, a flat state, the surface thin material 16 and the back surface thin material 18 are bonded to the front and back of the sheet base material 14.

  The surface thin material 16 and the back thin material 18 are PET films, and are respectively attached to the front and back of the sheet base material 14 in which the RFID inlay 12 is embedded. Further, the surface thin material 16 is provided with a toner fixing layer 17 (see FIG. 1) on its surface, and serves as a printing surface with toner. The surface of the surface material 16 may be provided with an ink coating layer instead of the toner fixing layer 17 and printed by another printing method so as to print with ink.

  When the RFID inlay 12 is disposed at a predetermined position on the sheet base material 14 and the surfaces of the sheet base material 14 and the RFID inlay 12 are flattened, the maximum distortion rate of the sheet base material 14 due to the tip of the IC chip 24 is about 50%. Become. Since the compressive stress Pe becomes P2 when the sheet base material 14 is compressed by about 50%, the RFID inlay 12 is subjected to a maximum P2 compressive stress.

  P2 which is the maximum value of the compressive stress Pe applied to the RFID inlay 12 is a value equal to or less than P1 which is the stress limit value of the RFID inlay 12. Therefore, the compressive stress Pe in the portion having the maximum thickness width of the RFID inlay 12 is equal to or less than the stress limit value P1 of the RFID inlay 12, and the compressive stress from the sheet base material 14 does not cause damage or the like.

  For example, a predetermined image is printed on the RFID sheet 10 as a menu. The content associated with the menu image or the like is stored in the IC chip 24 of the RFID inlay 12. An RFID inlay 12 is attached in the vicinity of the display content printed on the RFID sheet 10.

  Then, when the operator brings the reader close to the display portion and performs communication with the RFID inlay 12, the reader obtains the code number of the displayed item from the RFID inlay 12. Furthermore, an order can be easily received by inputting the number of items.

  Thus, when the RFID inlay 12 is attached to the sheet base material 14 having the above characteristics to form the RFID sheet 10, the RFID inlay 12 is not damaged by the compressive stress from the sheet base material 14 and a communication failure occurs. I will not let you. Moreover, the RFID sheet 10 has a flat surface, does not cause any trouble in printing, and on the back surface, the convex portion by the IC chip 24 is completely buried in the sheet base material 14, and the opposite surface of the sheet base material 14. It does not protrude.

  The surfaces of the RFID inlay 12 and the sheet base material 14 are not limited to a flat state having no step, and a step between them may be provided within a predetermined range. For example, the allowable level difference is, for example, a range that does not hinder printing on the surface or the printing process. Even when a step is provided between the RFID inlay 12 and the sheet base material 14, the relationship of maximum value of compressive stress Pe applied to the RFID inlay 12 <stress limit value Pd is satisfied.

Second Embodiment Next, an RFID sheet 11 according to a second embodiment of the present invention will be described.

  The RFID sheet 11 is a water-resistant paper for a laser printer, which includes an RFID inlay 12, a sheet base material 15 to which the RFID inlay 12 is attached, a surface thin material 16 and a back thin material 18 to be attached to the sheet base material 15. There is no special difference between the RFID sheet 10 and the basic structure. 1 is shared with the RFID sheet 10.

  The RFID inlay 12 is basically the same as the RFID inlay 12 of the first embodiment, and the maximum height width is H1. The sheet base material 15 has the same hardness as the sheet base material 14.

  However, the sheet base material 15 has a thickness width of W2. As a result, when the RFID inlay 12 is embedded in the sheet base material 15 so that the surfaces of the RFID inlay 12 and the sheet base material 15 become flat, the distortion rate E becomes about 70%, and the RFID inlay 12 The maximum value of the compressive stress Pe applied to 12 is P3. When the RFID inlay 12 is attached to the sheet base material 15 and both surfaces are flattened, the surface thin material 16 and the back surface thin material 18 are attached to the front and back surfaces, respectively.

  The compressive stress P3 is a value that does not exceed the stress limit value P1 of the RFID inlay 12 and is just before the stress limit value P1. Furthermore, the compressive stress P3 is a value located in the vicinity of the value of the inflection point S in the graph showing the relationship between the strain rate E of the sheet base material 15 and the compressive stress Pe.

  Therefore, the RFID sheet 11 constituted by the combination of the RFID inlay 12 and the sheet base material 15 has the minimum thickness W2 and the hardness K1 that the sheet base material 15 does not damage the RFID inlay 12 or the like. In addition, the maximum compression portion by the RFID inlay 12 is thin with little room for compression.

  This will be explained in a little more detail. When the RFID inlay 12 is attached to the sheet base material 15 so that the surface thereof is flat, the maximum compressive stress P3 applied to the RFID inlay 12 is a value immediately before the stress limit value P1. It is the hardest material allowed for the RFID inlay 12.

  Furthermore, since P3 is located in the vicinity of the inflection point S of the graph showing the relationship between the strain rate E and the compressive stress Pe of the sheet base material 15, the thickness W2 of the sheet base material 15 is allowed. The thinnest thickness. That is, when the thickness of the sheet base material 15 is further reduced, the Pe value exceeds the inflection point S, and the compressive stress Pe is greatly increased only by a slight increase in thickness. As a result, the value of the compressive stress becomes unstable, and an excessive compressive stress may be applied to the RFID inlay 12 due to a slight disturbance such as vibration. In this respect, the sheet base material 15 is compressed to the limit. Thin thickness.

  On the other hand, if the value of the compressive stress P3 of the RFID inlay 12 is set to a low value, for example, away from the inflection point S, the sheet base material 15 is considered to have left sufficient room for compression. In other words, the RFID sheet 11 is softer than necessary and has no waist.

  Therefore, when the RFID inlay 12 is pushed into the sheet base material 15, the compressive stress Pe received by the RFID inlay 12 from the sheet base material 15 is a value close to a range that does not exceed the stress limit value P1 of the RFID inlay 12, and When the RFID inlay 12 and the sheet base material 15 are selected so that the state at that time is located in the vicinity of the inflection point S of the sheet base material 14, the thickness of the sheet base material 15 is thin and the hardness is increased. It is possible to provide the RFID sheet 11 that gives a firm feeling and does not apply excessive compressive stress to the RFID inlay 12.

  The sheet base material 14 or the like may be made of a material that is plastically deformed. Thus, even after the RFID inlay 12 is embedded in the sheet base material 14 or the like, the elastic stress on the RFID inlay 12 is maintained even when the upper and lower surfaces of the sheet base material 14 are sealed with the front surface thin material 16 and the back surface thin material 18. That is, a repulsive force that causes the sheet base material 14 to return to the original shape is not applied to the RFID inlay 12, and it is possible to provide an RFID sheet with a low risk of breaking the IC chip 24 of the RFID inlay 12 after manufacture.

  Further, the sheet base material 14 or the like is made of a material that has a characteristic of being softened at a high temperature and being hardened at a high temperature in an environmental temperature range where the RFID sheet is used. Then, when the RFID inlay 12 is embedded, the sheet base material 14 is heated and temporarily softened, whereby the embedding is completed with a lower compressive stress, and the fracture risk of the IC chip 24 can be further reduced. And it can provide as a moderately hardened RFID sheet | seat by returning to the state of use environment temperature, normally normal temperature.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 10, 11 ... RFID sheet | seat, 12 ... RFID inlay, 14, 15 ... Sheet base material, 16 ... Surface thin material, 17 ... Toner fixing layer, 18 ... Back surface thin material, 22 ... Antenna member, 24 ... IC chip, 26 ... Resin film, Pe ... compressive stress, Pd ... stress limit value, E ... strain rate, K1 ... hardness, S ... inflection point.

Claims (5)

A sheet substrate;
RFID inlay attached to the surface of the sheet substrate,
Compressive stress that the RFID inlay receives from the sheet base material when the RFID inlay is attached to the sheet base material so that a surface step generated between the RFID inlay and the sheet base material is within a predetermined range. An RFID sheet, wherein the RFID inlay and the sheet base material satisfy a relationship in which a maximum value of Pe does not exceed a stress limit value Pd of the RFID inlay. A sheet substrate;
An RFID inlay affixed to the surface of the sheet base material,
Compressive stress that the RFID inlay receives from the sheet base material when the RFID inlay is attached to the sheet base material so that a surface step generated between the RFID inlay and the sheet base material is within a predetermined range. Near the inflection point S of the graph in which the maximum value of Pe is equal to or less than the stress limit value Pd of the RFID inlay and the maximum value of the compressive stress Pe indicates the strain rate E and the compressive stress Pe of the sheet base material The RFID sheet is characterized in that the RFID inlay and the sheet base material satisfy the relationship set in (1).   The RFID sheet according to claim 1, wherein a surface step generated between the RFID inlay and the sheet base material is in a flat state without a step between the two.   The thickness width of the sheet base material is larger than the maximum thickness of the RFID inlay, and a convex portion by an IC chip mounted on the RFID inlay is provided so as to face the sheet base material. The RFID sheet according to any one of claims 1 to 3, wherein:   The RFID sheet according to any one of claims 1 to 4, wherein the sheet base material is made of a material that softens at a high temperature and hardens at a normal temperature from a high temperature state.