RFID tag and tag

Abstract

To provide an RFID tag that can suppress a decrease in communication performance even when the tag size is reduced, and can improve versatility.SOLUTION: An RFID tag 1 includes an IC chip 21 on which identification information is recorded, a loop-shaped conductor 22 formed in a ring shape and connected to the IC chip 21, a pair of rectangular conductors 23A, 23B formed in a rectangular shape and extending from the loop-shaped conductor 22 on both sides in the longitudinal direction of the rectangular shape of the RFID tag 1, and a slit 25 formed from a central gap 26 of the loop-shaped conductor 22 to one of the pair of rectangular conductors 23A, 23B in a direction away from the IC chip 21.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to RFID tags and hang tags. [Background technology]

[0002] 2. Description of the Related Art There is a known method for managing items with high accuracy and ease by attaching an RFID (Radio Frequency Identification) tag to the item to be managed and reading and writing information about the item to and from the tag.

[0003] For example, Patent Document 1 describes a configuration in which an RFID tag is attached to a cover or the like during bookbinding and used for book management. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2002-326474 Summary of the Invention [Problem to be solved by the invention]

[0005] When applying RFID tags to manage goods, it is desirable to reduce the tag size in order to improve versatility. However, when the tag size is reduced, the inlay size also becomes smaller in proportion. This may result in a decrease in the communication performance of the tag.

[0006] An object of the present disclosure is to provide an RFID tag that can suppress a decrease in communication performance even when the tag size is reduced, and can improve versatility. [Means for solving the problem]

[0007] An RFID tag according to one aspect of an embodiment of the present invention is a rectangular RFID tag comprising an IC chip on which identification information is recorded, a loop-shaped conductor formed in a ring shape and connected to the IC chip, a pair of rectangular conductors formed in a rectangular shape extending from the loop-shaped conductor on both sides of the longitudinal direction of the rectangle, and a slit formed from a central gap of the loop-shaped conductor to one of the pair of rectangular conductors in a direction away from the IC chip.

[0008] According to this aspect, in the inlay of the RFID tag, a slit is formed from the central gap of the loop-shaped conductor to one of a pair of rectangular conductors in a direction away from the IC chip, so that the slit can compensate for the reduction in the area of ​​the gap of the loop-shaped conductor even when the tag is made smaller, thereby suppressing the deterioration of communication performance even when the tag size is reduced, and improving versatility.

[0009] In an RFID tag according to another aspect of the embodiment of the present invention, the IC chip may be arranged in the center of the RFID tag in the longitudinal direction.

[0010] According to this aspect, regardless of the direction along the longitudinal direction of the RFID tag that the reading operation is performed from using a reading device, it is possible to make it difficult for differences to occur in the relative positional relationship between the IC chip and the reading device, thereby making it possible to make the accuracy of reading information from the RFID tag more uniform.

[0011] In an RFID tag according to another aspect of the embodiment of the present invention, the IC chip may be further arranged at the center of the RFID tag in the lateral direction.

[0012] According to this embodiment, the IC chip is positioned at the center of the length and width of the RFID tag, so that no matter which direction in the length or width of the RFID tag a reading operation is performed from using a reading device, there is unlikely to be any difference in the relative positional relationship between the IC chip and the reading device, making it possible to further standardize the accuracy of reading information from the RFID tag.

[0013] In an RFID tag according to another aspect of an embodiment of the present invention, each of the pair of rectangular conductors may be provided with a protrusion that protrudes outward in the short side direction from the loop conductor from at least one of both ends of the short side direction of the rectangle, and may be configured to have a strip portion that protrudes from the protrusion along the longitudinal direction toward the center side of the longitudinal direction and is formed in a strip shape.

[0014] According to this aspect, by forming a conductor pattern including the protrusions and the strip portions, it is possible to further suppress the deterioration of communication performance.

[0015] In an RFID tag according to another aspect of an embodiment of the present invention, the loop-shaped conductor has a pair of first opposite side portions extending in the short side direction and arranged opposite each other in the long side direction, and a pair of second opposite side portions extending in the long side direction and arranged opposite each other in the short side direction, and the strip portions may include a pair of strip portions protruding from the protruding portions of the pair of rectangular conductors on one side of the pair of second opposite side portions.

[0016] According to this aspect, by forming a conductor pattern including a pair of strip portions, it is possible to further suppress the deterioration of communication performance.

[0017] In an RFID tag according to another aspect of an embodiment of the present invention, the strip portion may further include another pair of strip portions protruding from the protruding portions of the pair of rectangular conductors on the other side of the pair of second opposing sides.

[0018] According to this aspect, by forming a conductor pattern having two pairs of strip portions, it is possible to further suppress the deterioration of communication performance.

[0019] In an RFID tag according to another aspect of the embodiment of the present invention, the strip portion may be configured so as not to overlap the portion of the loop-shaped conductor on which the IC chip is installed when viewed from the short side direction.

[0020] According to this aspect, by forming the strip portions in this manner, it is possible to further suppress the deterioration of communication performance.

[0021] A tag according to one aspect of an embodiment of the present invention is a tag to which a rectangular RFID tag is attached, the RFID tag having an IC chip on which identification information is recorded, a loop-shaped conductor formed in a ring shape and connected to the IC chip, a pair of rectangular conductors formed in a rectangular shape extending from the loop-shaped conductor on both sides of the longitudinal direction of the rectangular shape, and a slit formed from a central gap of the loop-shaped conductor to one of the pair of rectangular conductors in a direction away from the IC chip, and is provided with a perforation provided at a position intersecting the slit of the RFID tag.

[0022] According to this embodiment, the RFID tag can be completely disabled and discarded by cutting the tag at the perforation that intersects with the slit of the RFID tag built into the tag. Therefore, once the tag is cut, it is possible to prevent information from being read from the remaining part of the RFID tag's IC chip, ensuring security after the RFID tag is discarded. Effect of the Invention

[0023] According to the present disclosure, it is possible to provide an RFID tag that can suppress a decrease in communication performance even when the tag size is reduced and can improve versatility. [Brief description of the drawings]

[0024] [Figure 1] A cross-sectional view of the RFID tag according to the first embodiment. [Diagram 2] A top view of the RFID tag shown in Figure 1. [Diagram 3] FIG. 3 is a diagram showing an example of dimensions of each part of the conductor pattern of the inlay shown in FIG. [Figure 4] FIG. 1 is a diagram showing an example of a configuration for attaching an RFID tag according to a first embodiment to a book as an object to which the tag is to be attached; [Diagram 5]A diagram showing an example of a method for reading information from RFID tags attached to multiple books as objects to be affixed. [Figure 6] 1 is a plan view of an RFID tag according to a first modified example; [Figure 7] 11 is a plan view of an RFID tag according to a second modified example. [Figure 8] 13 is a plan view of an RFID tag according to a third modified example. [Figure 9] 1 is a plan view of an RFID tag according to a second embodiment; [Figure 10] A plan view of a tag according to a third embodiment. [Figure 11] Schematic diagram of the measurement environment for the first test according to Example 1 [Figure 12] Plan view of the measurement environment shown in Figure 11 [Figure 13] FIG. 1 is a plan view showing the conductor pattern of an RFID tag used in Comparative Examples 1 and 2. [Figure 14] FIG. 13 is a graph showing frequency characteristics of Example 3 and Comparative Example 3 measured in the second test. [Figure 15] FIG. 13 is a graph showing the frequency characteristics of Examples 4 and 5 measured in the second test. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, an embodiment will be described with reference to the accompanying drawings. In order to facilitate understanding of the description, the same components in each drawing are denoted by the same reference numerals as much as possible, and duplicated description will be omitted.

[0026] [First embodiment] The first embodiment will be described with reference to FIGS.

[0027] In the following description, the X direction, Y direction, and Z direction are perpendicular to each other. The Z direction is the longitudinal direction of each component of the RFID tag 1 such as the inlay 2. The Y direction is the short-side direction of each element of the RFID tag 1 such as the inlay 2. The Z direction is the stacking direction of each component of the RFID tag such as the inlay 2. Also, hereinafter, for convenience of explanation, the positive direction side of the Z axis may be expressed as the front side or the upper side, and the negative direction side of the Z axis may be expressed as the back side or the lower side.

[0028] <Structure of RFID Tag 1> FIG. 1 is a cross-sectional view of the stack of the RFID tag 1 according to the first embodiment. FIG. 2 is a plan view of the RFID tag 1 shown in FIG. 1 as viewed from above. In FIG. 2, only the elements related to the inlay 2 in FIG. 1 are shown. The RFID tag 1 is a substantially planar device to be attached to an object to be attached. As shown in FIGS. 1 and 2, the RFID tag 1 incorporates an inlay 2.

[0029] The object to be attached includes, for example, a book 30 such as a book or a magazine as will be described later with reference to FIG. 4 and the like. Also, the object to be attached is not limited to the book 30, and may be an article mainly stacked vertically or horizontally during storage, an article formed by stacking a large amount of paper in the same manner as the book 30, or an article formed of a material containing moisture such as paper in the same manner as the book 30. Examples of such articles include cards such as trading cards, stationery such as clear files and notebooks, foods such as confectionery, newspapers, tickets, and vouchers.

[0030] Also, the object to be attached includes clothing and the like. In this case, the RFID tag 1 is attached or incorporated in a hanging tag 10 (see FIG. 10) attached to a product, for example, at the time of selling a product such as clothing.

[0031] The RFID tag 1 of the first embodiment is flexible and preferably can be attached to an adherend even if the surface of the adherend is curved. Even when bent into a curved shape, the RFID tag 1 of the first embodiment can exhibit good communication performance and can be used to identify objects having curved surfaces, thus diversifying applications. The RFID tag 1 is formed in a rectangular shape with the X direction as the longitudinal direction and the Y direction as the transverse direction in a plan view seen from the Z direction as shown in Fig. 2.

[0032] The inlay 2 is a portion including elements related to the function of the RFID tag 1, and includes an IC chip 21 in which identification information is recorded, a loop conductor 22 connected to the IC chip 21, and a pair of rectangular conductors 23A and 23B, as shown in Fig. 2. In the following description, the pair of rectangular conductors 23A and 23B may be collectively referred to as "rectangular conductors 23", and are labeled as such in Fig. 1.

[0033] The inlay 2 has a loop-shaped conductor 22 and a rectangular conductor 23 formed by dry laminating an aluminum sheet on a base material 24, such as a synthetic resin film such as polyethylene terephthalate or polypropylene, and an IC chip 21 mounted at a specified position.

[0034] The IC chip 21 has an internal capacitance, and the inductance of the rectangular conductor 23 and the internal capacitance of the IC chip 21 form a matching circuit.

[0035] The loop-shaped conductor 22 is a conductive wiring pattern having a loop-like (annular) shape of one turn or less when viewed in a plan view from the Z direction. In the first embodiment, the loop-shaped conductor 22 has a pair of first opposite side portions 221A, 221B and a pair of second opposite side portions 222A, 222B, as shown in Fig. 2. The first opposite side portions 221A, 221B extend in the short side direction (Y direction) and are arranged opposite to each other in the long side direction (X direction). The second opposite side portions 222A, 222B extend in the long side direction (X direction) and are arranged opposite to each other in the short side direction (Y direction).

[0036] Of the pair of first opposite side portions 221A, 221B, one first opposite side portion 221A is arranged on the X negative direction side (left side in FIG. 2), and the other first opposite side portion 221B is arranged on the X positive direction side (right side in FIG. 2). Of the pair of second opposite side portions 222A, 222B, one second opposite side portion 222A is arranged on the Y positive direction side (upper side in FIG. 2), and the other second opposite side portion 222B is arranged on the Y negative direction side (lower side in FIG. 2).

[0037] The loop conductor 22 is electrically connected to the IC chip 21 and the rectangular conductor 23. When the identification information recorded in the IC chip 21 is read by the RFID reader 40 (see FIG. 5, etc.), when the rectangular conductor 23 of the inlay 2 receives radio waves in the UHF band, for example, radio waves around 920 MHz, a current flows through the loop conductor 22 due to resonance. This generates an electromotive force that operates the IC chip 21. When the IC chip 21 operates, the identification information recorded in the IC chip 21 is encoded by the IC chip 21, and the encoded data is wirelessly transmitted to a communication device such as the RFID reader 40 using radio waves around 920 MHz as a carrier wave. The RFID reader 40 that receives this signal combines the signal and transfers it to an external device. In this way, the RFID tag 1 of this embodiment is a passive radio wave type wireless tag that does not have a power source (battery) for holding and transmitting the identification information. Therefore, compared to an active wireless tag that has a battery, it can be made smaller and less expensive because it does not have a battery.

[0038] The loop-shaped conductor 22 is disposed in the approximate center of the inlay 2, as shown in Fig. 2, for example. The IC chip 21 is disposed above the loop-shaped conductor 22 in an overlapping manner and electrically connected to the loop-shaped conductor 22. In the first embodiment, one second opposite side portion 222A of the loop-shaped conductor 22 is disposed at the center position in the short-side direction (Y direction) of the RFID tag 1, and a connection position with the IC chip 21 is provided at the approximate center position in the X direction of one second opposite side portion 222A. As a result, when the IC chip 21 is connected to the loop-shaped conductor 22, the IC chip 21 is disposed at the center position in the long-side direction and short-side direction of the RFID tag 1.

[0039] The pair of rectangular conductors 23A, 23B extend from a pair of first opposite sides 221A, 221B of the loop conductor 22 to both sides in the longitudinal direction (X direction) of the tag, and are formed in a rectangular shape. Note that the term "rectangular shape" used in this embodiment includes a substantially rectangular shape, and also includes a case where the lengths of two adjacent sides are slightly different, or an adjacent angle is not an exact right angle, etc. In this embodiment, the portions of the rectangular conductors 23A, 23B located on the Y positive direction side (upper side in FIG. 2) of one of the second opposite sides 222A extend toward the center in the longitudinal direction from the first opposite sides 221A, 221B, respectively, and are formed so as to have a gap between them. The width of this gap in the X direction is larger than the width of the IC chip 21 in the X direction when it is installed on the loop conductor 22, for example, as shown in FIG. 2.

[0040] In addition, a pair of protrusions 231 are provided in each of the pair of rectangular conductors 23A and 23B, protruding outward in the short-side direction (Y direction) from the loop conductor 22 at both ends in the short-side direction (Y direction) of the tag. One rectangular conductor 23A has a pair of protrusions 231A and 231B, one protrusion 231A protruding in the Y positive direction and the other protrusion 231B protruding in the Y negative direction. The other rectangular conductor 23B has a pair of protrusions 231C and 231D, one protrusion 231C protruding in the Y positive direction and the other protrusion 231D protruding in the Y negative direction. In the example of FIG. 2, the outer edge of each protrusion 231 in the X direction is arranged to be in the same position as the outer edge of the rectangular conductor 23 in the X direction. In Figure 2, for ease of explanation, the boundary line on the Y-direction center side (the side of the second virtual line VS) of the pair of protrusions 231A, 231B of one rectangular conductor 23A and the boundary line on the Y-direction center side of the pair of protrusions 231C, 231D of the other rectangular conductor 23B are illustrated with dotted lines, but in reality, each of the protrusions 231A to 231D is formed integrally with the rectangular conductors 23A, 23B.

[0041] Further, the pair of rectangular conductors 23A and 23B are provided with strip parts 232 (232A, 232B, 232C, 232D) that are formed in a strip shape and are provided to protrude from the protruding part 231 along the longitudinal direction toward the center side of the longitudinal direction (X direction) of the tag. In one rectangular conductor 23A, the strip parts 232A and 232B are formed so as to protrude from the pair of protruding parts 231A and 231B along the X direction in the X positive direction. In the other rectangular conductor 23B, the strip parts 232C and 232D are formed so as to protrude from the pair of protruding parts 231C and 231D along the X direction in the X negative direction. In the example of FIG. 2, the outer edge of each strip part 232 in the Y direction is arranged to be in the same position as the outer edge of the protruding part 231 in the Y direction. In FIG. 2, for ease of explanation, the boundary between the base end portion on the negative X-direction side of a pair of strip portions 232A, 232B of one rectangular conductor 23A and each of the protrusions 231A, 231B, and the boundary between the base end portion on the positive X-direction side of a pair of strip portions 232C, 232D of the other rectangular conductor 23B and each of the protrusions 231C, 231D are shown by dotted lines; however, in reality, each of the strip portions 232A to 232D is formed integrally with the rectangular conductors 23A, 23B.

[0042] In other words, the strip portion 232 includes a pair of strip portions 232A, 232C protruding from the protruding portions 231A, 231C of the pair of rectangular conductors 23A, 23B on the side of one second opposite side 222A of the loop-shaped conductor 22. Similarly, the strip portion 232 includes a pair of strip portions 232B, 232D protruding from the protruding portions 231B, 231D of the pair of rectangular conductors 23A, 23B on the side of the other second opposite side 222B (see FIG. 2).

[0043] 2, it is preferable that each strip portion 232 is formed so as not to overlap with the portion of the loop-shaped conductor 22 where the IC chip 21 is placed when viewed from the short side direction (Y direction) of the tag. This prevents the conductor pattern from being present on the outer side of the IC chip 21 in the Y direction, which is believed to improve the wireless transmission performance of the IC chip 21, particularly in the Y direction, and further suppresses deterioration of communication performance caused by the effects of moisture contained in the object to be affixed and the effects of RFID tags being close to each other when affixed to multiple objects to be affixed.

[0044] Further, the width (dimension in the Y direction) of each strip portion 232 is formed smaller than the amount of protrusion in the Y direction from the rectangular conductor 23 of each protrusion 231. As a result, a gap is formed between each strip portion 232 and the rectangular conductor 23 or between each strip portion 232 and the loop conductor 22.

[0045] The pair of rectangular conductors 23A, 23B function as a dipole antenna configured to exhibit resonance characteristics with the IC chip 21 for radio wave frequencies for wireless communication (e.g., UHF band frequencies). The rectangular conductors 23A, 23B as dipole antennas have an overall electrical length equivalent to approximately λ / 2 (λ is the communication wavelength). The pair of rectangular conductors 23A, 23B have a structure that achieves impedance conjugate matching with the IC chip 21 for radio waves with frequencies, for example, around 920 MHz (e.g., 860 MHz to 960 MHz, more preferably 915 MHz to 935 MHz).

[0046] Particularly in the first embodiment, the inlay 2 includes a slit 25. The slit 25 is formed in a direction away from the IC chip 21 from a gap 26 in the center of the loop-shaped conductor 22 to one of the rectangular conductors 23B. The gap 26 is a non-conductive portion surrounded by a pair of first opposite sides 221A, 221B and a pair of second opposite sides 222A, 222B of the loop-shaped conductor 22. Like the gap 26, the slit 25 is also non-conductive.

[0047] 2, the slit 25 is formed to penetrate from the gap 26 through the first opposite side 221B and extend toward the negative X direction in parallel with the extending direction of the second opposite side 222A, 222B and the longitudinal direction of the RFID tag 1. As shown by the dotted line in Fig. 2, the peripheral portion of the slit 25 can also function as a part of the loop-shaped conductor 22. In other words, the loop-shaped conductor 22 has a single gap portion formed by the gap 26 and the slit 25, and is formed in a ring shape around this gap portion.

[0048] 2, the extension direction of the slit 25 is the X direction parallel to the longitudinal direction of the RFID tag 1, but the slit 25 may be formed at least in a direction away from the IC chip 21, and may be formed to extend in a direction inclined with respect to the X direction, for example. In the example of Fig. 2, the slit 25 is provided in one rectangular conductor 23B on the X positive direction side of the pair of rectangular conductors 23A, 23B, but the slit 25 may be provided in the other rectangular conductor 23A on the X negative direction side. In this case, the slit 25 is formed penetrating from the gap 26 through the first opposite side portion 221A.

[0049] The conductive wiring pattern of the inlay 2, including the loop-shaped conductor 22 and the rectangular conductor 23, can be formed by existing methods such as pressing or etching copper foil or aluminum foil, plating, silk screen printing of metal paste, or metal wire, but here it is formed by etching aluminum.

[0050] As shown in Fig. 2, the conductive wiring pattern of the inlay 2 including the loop conductor 22 and the rectangular conductor 23 is preferably formed symmetrically with respect to a first imaginary line VL passing through approximately the center of the RFID tag 1 in the longitudinal direction in a plan view (the position where the IC chip 21 in Fig. 2 is placed), except for the slit 25 portion. The first imaginary line VL is a line parallel to the XY plane and extending in the Y direction. The first imaginary line VL is also a line that approximately bisects the RFID tag 1 into regions in the X direction. In Fig. 2, the first imaginary line VL is indicated by a dashed line extending along the Y direction.

[0051] Similarly, as shown in Fig. 2, the conductive wiring pattern of the inlay 2 including the rectangular conductor 23 is preferably formed symmetrically with respect to a second imaginary line VS passing through approximately the center of the short side of the RFID tag 1 in a plan view, except for the loop conductor 22. The second imaginary line VS is a line parallel to the XY plane and extending in the X direction. The second imaginary line VS is also a line that approximately bisects the RFID tag 1 into areas in the Y direction. In Fig. 2, the second imaginary line VS is indicated by a dashed line extending along the X direction.

[0052] In the first embodiment, the IC chip 21 is placed at the center of the RFID tag 1 in the longitudinal and lateral directions, which is the point where the first virtual line VL and the second virtual line VS intersect.

[0053] In addition, with such an arrangement of the IC chip 21, the first opposite side portions 221A, 221B and the second opposite side portions 222A, 222B of the loop-shaped conductor 22 are arranged to be line-symmetrical with respect to the first virtual line VL, and are arranged on the Y negative side of the second virtual line VS. That is, the first opposite side portions 221A, 221B are formed so that the end portions on the Y positive side in the extension direction (Y direction) are substantially in the same position as the second virtual line VS, and the end portions on the Y negative side are in the same position as the end portions on the Y negative side of the rectangular conductors 23A, 23B. The end position on the Y negative side of the second opposite side portion 222B is the same as the end positions on the Y negative side of the rectangular conductors 23A, 23B. That is, the second opposite side portion 222B and the rectangular conductors 23A, 23B are formed so that the end portions on the Y negative side are in a straight line along the X direction. The second opposite side portion 222A is disposed at the center of the RFID tag 1 in the short side direction (Y direction).

[0054] 2, for convenience of explanation, the boundary between one rectangular conductor 23A and one first opposite side portion 221A and the boundary between the other rectangular conductor 23B and the other first opposite side portion 221B are illustrated by dotted lines, but in reality, the pair of rectangular conductors 23A, 23B are formed integrally with the loop conductor 22. In other words, the boundary between the pair of rectangular conductors 23A, 23B and the pair of first opposite side portions 221A, 221B, the boundary between the pair of rectangular conductors 23A, 23B and the four protruding portions 231A to 231D, the boundary between the four protruding portions 231A to 231D and the four strip portions 232A to 232D, and the boundary between the loop conductor 22 around the slit 25 and the rectangular conductor 23B are not actually formed on the conductor pattern of the inlay 2.

[0055] Fig. 3 is a diagram showing an example of the dimensions of each portion of the conductor pattern of the inlay 2 shown in Fig. 2. In the example of dimensions shown in Fig. 3, all of the conditions related to the shapes of the loop conductor 22 and rectangular conductor 23 described above are satisfied.

[0056] Here, in the RFID tag 1 of the first embodiment, the dimension of the inlay 2 in the longitudinal direction (X direction) is 70 mm, and the dimension of the inlay 2 in the lateral direction (Y direction) is 14 mm.

[0057] 3, the longitudinal dimension (X direction) of each of the strip portions 232A-232D is 14.6 mm, and the width dimension in the Y direction is 0.5 mm. The gap dimension in the Y direction between each of the strip portions 232A-232D and the rectangular conductors 23A and 23B is 1.0 mm. The dimension from the negative X direction end of the rectangular conductor 23A to the base of the strip portions 232A and 232B, and the dimension from the positive X direction end of the rectangular conductor 23B to the base of the strip portions 232C and 232D are 15.0 mm.

[0058] In the loop-shaped conductor 22, the dimension of the gap 26 in the X direction is 4.5 mm, and the dimension in the Y direction is 3.0 mm. The dimension of the slit 25 in the longitudinal direction (X direction) is 26.0 mm, and the width dimension in the Y direction is 1.5 mm.

[0059] The area of ​​the slit 25, i.e., the product of the longitudinal dimension and the width dimension, is preferably as large as possible. In the case of a tag having a size as shown in FIG. 3, the area of ​​the slit 25 is 35.0 to 43.0 mm. 2 is preferable, and 36.0 to 41.0 mm 2 It is more preferable that the width of the slit 25 in the Y direction is set to an upper limit of 3.0 mm.

[0060] As described above, the RFID tag 1 of the first embodiment is configured to include the loop conductor 22 and rectangular conductor 23 formed by the conductive pattern shown in Figure 2, and this makes it possible to suppress deterioration in communication performance due to the effects of moisture contained in the object to which the RFID tag is attached and the effects of RFID tags being in close proximity to each other when the RFID tags are attached to multiple objects to which the RFID tags are attached.

[0061] Furthermore, by providing the slit 25, it is possible to compensate for the reduction in the area of ​​the gap 26 of the loop-shaped conductor 22 even when the tag is miniaturized. It is known that when the area of ​​the gap 26 of the loop-shaped conductor 22 is reduced, the peak frequency band in the frequency characteristics of the tag tends to shift to the lower frequency side. In the first embodiment, the reduction in the area of ​​the gap 26 of the loop-shaped conductor 22 can be suppressed by the amount of the slit 25, so that the transition of the peak frequency band to the lower frequency side can be suppressed. This makes it easier to adjust the peak frequency band so that the usage frequency is included, even when the tag is miniaturized.

[0062] In the first embodiment, for convenience of explanation, the loop-shaped conductor 22 and the rectangular conductor 23 are separate elements, and are shown separated by a dotted line in Fig. 2. However, in this embodiment, as described above, the loop-shaped conductor 22 and the rectangular conductor 23 are actually formed integrally, and the separation position between the loop-shaped conductor 22 and the rectangular conductor 23 shown by the dotted line in Fig. 2 is merely an example. In other words, in the first embodiment, not only the rectangular conductor 23 but also at least a part of the loop-shaped conductor 22 may function as an antenna portion. Similarly, at least a part of the rectangular conductor 23 may function as a loop conductor.

[0063] 1, in the RFID tag 1 of the first embodiment, a label paper (film-based tack paper) 3 is further disposed above the inlay 2. The label paper 3 is printable on its surface on the positive side of the Z axis. The material of the label paper 3 can be appropriately selected, and materials other than paper, such as resin materials, may be used as long as they are printable.

[0064] The label paper 3 is also formed so that its dimension in the X direction is larger than that of the inlay 2, with the inlay 2 located in its central portion and excess portions on both sides in the X direction that do not overlap with the inlay 2. An adhesive portion 4 having adhesiveness is provided on the back surface of this excess portion on the negative side of the Z axis, the surface that comes into contact with the object to be affixed (the lower surface in FIG. 1). In this way, the inlay 2 and the adhesive portion 4 are arranged so as not to overlap in a plan view. In the example of FIG. 1, a pair of adhesive portions 4A, 4B are arranged on the positive and negative sides of the X axis with respect to the inlay 2.

[0065] The adhesive portion 4 comes into contact with the object to which it is to be attached and adheres to the object by its adhesive force, whereby the entire RFID tag 1 is attached to the object to which it is to be attached.

[0066] The adhesive portion 4 is preferably formed, for example, from an adhesive hot melt. A hot melt is a thermoplastic adhesive that is solid at room temperature but liquefied by heating and melting, is applied to an adherend, and forms a bond by cooling and solidifying. An adhesive hot melt is one that has adhesive power on the exposed surface even after cooling and solidifying. The adhesive portion 4 is preferably formed using biological resources (biomass) or biodegradable materials. The biomass content of the adhesive portion 4 is, for example, 25%.

[0067] Additionally, a bonding portion 5 is laminated on the back surface of the label paper 3 on the negative side of the Z axis. The bonding portion 5 is bonded to the upper surface of the inlay 2 and the upper surface of the adhesive portion 4, so that the inlay 2 and the adhesive portion 4 are covered by the label paper 3. Additionally, when laminated, the bonding portion 5 can enter into the gap formed by the inlay 2 and the label paper 3 above it, and fill this gap.

[0068] The joint 5 is preferably formed, for example, from a non-adhesive hot melt. A non-adhesive hot melt is one that has no adhesive power on the exposed surface after cooling and solidifying. Like the adhesive part 4, the joint 5 is preferably formed using biological resources (biomass) or biodegradable materials.

[0069] Furthermore, before use, the RFID tag 1 has a release paper 6 disposed below the adhesive portion 4. The release paper 6 is formed, for example, to be the same size as or larger than the label paper 3, and the label paper 3 and the release paper 6 are adhered to each other by the adhesive portion 4. This prevents a pair of adhesive portions 4A, 4B on both sides of the label paper 3 in the X direction from being exposed to the outside before being used to attach the RFID tag 1 to an object, and allows the adhesive force to be maintained. When the RFID tag 1 is used, the release paper 6 is peeled off from the RFID tag 1, and the exposed adhesive portions 4A, 4B of the label paper 3 allow the RFID tag 1 to be attached to an object.

[0070] 1, a plurality of RFID tags 1 may be arranged on one sheet of release paper 6. This can improve the manufacturing efficiency and the transportation efficiency.

[0071] The thickness of the RFID tag 1 in the first embodiment in the Z direction (excluding the release paper 6) is 80 μm to 260 μm, and preferably 150 to 230 μm. The thickness of the adhesive portion 4 in the Z direction is preferably about 10 μm to 30 μm.

[0072] 1 and 2, a pair of adhesive parts 4A, 4B are arranged on the positive and negative sides of the X-axis with respect to the inlay 2. With this configuration, the inlay 2 itself is not directly attached to the object to which it is to be attached, but is indirectly attached to the object to which it is to be attached via the adhesive part 4.

[0073] The laminated structure of the RFID tag 101 is not limited to that shown in FIG. 1. For example, the label paper 3 may be configured to be the same size as the inlay 2. In this case, since the outer edge portion of the label paper 3 cannot come into contact with the object to which it is to be affixed, an adhesive portion 4 is provided on the entire lower surface of the base material 24 of the inlay 2 that faces the object to which it is to be affixed, and the inlay 2 is directly affixed to the object to which it is to be affixed. In addition, in the configuration shown in FIG. 1, an adhesive portion may be provided continuously between the pair of adhesive portions 4A, 4B to form a single adhesive layer. In this case, the inlay 2 is also directly affixed to the object to which it is to be affixed.

[0074] In addition, the RFID tag 1 may be configured such that elements such as a magnetic sheet, a spacer layer, and a dielectric layer are further laminated on the object side (lower side in FIG. 1) to which the inlay 2 is to be attached. The magnetic sheet is a sheet material containing a magnetic material, and it is preferable to use one having excellent magnetic shielding characteristics against radio waves in the frequency band (for example, UHF band) used for reading the IC chip 21. The spacer layer is an element for disposing the inlay 2 in a state of being separated from the object to be attached by its thickness, and is preferably formed of an insulator such as a woven fabric or non-woven fabric made of fibers such as cardboard or synthetic resin, or a sheet of an inorganic material such as ceramic glass. The dielectric layer is preferably formed of an insulating material having a relative dielectric constant of about 1.2 to 3.0, whereby the communication distance of the RFID tag 1 can be increased.

[0075] <Application Example of RFID Tag 1> FIG. 4 is a diagram showing an example of a configuration in which the RFID tag 1 according to the first embodiment is attached to a book 30 as an object to be attached. As shown in FIG. 4, when the object to be attached is the book 30, the RFID tag 1 can be attached to, for example, the back surface 31A of the back cover 31. Further, when the object to be attached is the book 30, various bibliographic information related to the book 30 to which this tag is attached can be recorded, for example, in the IC chip 21 of the RFID tag 1.

[0076] Also, when the object to be attached is the book 30, the attachment position of the RFID tag 1 is not limited to the example in FIG. 4, and may be other positions such as the front surface 31B of the back cover 31, the back surface 32A or back surface 32B of the front cover 32, the spine cover 33, the endpaper 34, and the cover 35. In order to accurately read the information from the RFID tag 1, the attachment position of the RFID tag 1 is preferably as close as possible to the outer surface of the book 30 so that there are as few shielding objects as possible between the RFID tag 1 and a reading device such as an RFID reader 40 (see FIG. 5).

[0077] Fig. 5 is a diagram showing an example of a method for reading information from RFID tags 1-1 to 1-5 affixed to a plurality of books 30-1 to 30-5 as objects to which the tags are to be affixed. As shown in Fig. 5, consider a case in which RFID tags 1-1 to 1-5 are affixed to a plurality of books 30-1 to 30-5, respectively, and these plurality of books 30-1 to 30-5 are stacked vertically in a flat pile.

[0078] In this case, a user approaches the stacked books 30-1 to 30-5 using a small, lightweight, portable reading device such as RFID reader 40 shown in Fig. 5, and operates RFID reader 40. This allows the information ID1 to ID5 about each of the books 30-1 to 30-5 recorded in each of the RFID tags 1-1 to 1-5 attached to each of the books 30-1 to 30-5 to be read collectively.

[0079] The reader may be of a fixed type, and books 30-1 to 30-5 may be placed flat within the readable range of the reader to read information ID1 to ID5 from each of the RFID tags 1-1 to 1-5. Even when a plurality of books 30-1 to 30-5 are closely arranged on a bookshelf, that is, when a plurality of books are stacked horizontally, the information ID1 to ID5 can be read all at once from each of the RFID tags 1-1 to 1-5 in the same manner as described above.

[0080] A book 30 is made by binding many pieces of paper. Many books 30-1 to 30-5 are often stacked flat as shown in FIG. 5 when sold or stored in a bookstore or in a library. For this reason, when an RFID tag 1 is attached to a cover part such as the front cover 32 or the back cover 31, or to an inside leaf 34 or a door 35 close to the cover part, the RFID tags 1-1 to 1-5 of each of the stacked books 30-1 to 30-5 may be sandwiched between the books above and below. For this reason, in the past, the communication distance of the RFID tag may be reduced due to the influence of the RFID tags attached to each of the books 30-1 to 30-5 being close to each other, or the influence of moisture contained in the many pieces of paper forming each of the books 30-1 to 30-5, and the like, and the reading accuracy of the RFID tag may be deteriorated. The same problem may occur when multiple books 30 are arranged closely together on a bookshelf.

[0081] On the other hand, as described above, the RFID tag 1 of the first embodiment is configured to include the loop conductor 22 and the rectangular conductor 23 formed by the conductive pattern shown in Fig. 2, and therefore it is possible to suppress the deterioration of communication performance caused by the influence of moisture contained in the object to which the RFID tags 1-1 to 1-5 are attached (for example, the book 30) and the influence of the RFID tags 1-1 to 1-5 attached to a plurality of objects to which the RFID tags are attached (for example, the books 30-1 to 30-5) being close to each other. Therefore, if the RFID tag 1 of the first embodiment is applied to an object to which the RFID tags 1-1 to 1-5 are attached, which is made by stacking a large number of papers, such as the book 30, the effect of suppressing the deterioration of communication performance can be more significantly exhibited. Furthermore, the same effect can be obtained even when a plurality of books 30-1 to 30-5 are stacked, so that it is possible to read the information ID1 to ID5 from each tag 1-1 to 1-5 with high accuracy.

[0082] As described above, in the RFID tag 1 of the first embodiment, the slit 25 is formed in the inlay 2 from the central gap 26 of the loop conductor 22 to one of the pair of rectangular conductors (the rectangular conductor 23B on the X-positive side in the example of FIG. 2) in a direction away from the IC chip 21, so that the slit 25 can compensate for the reduction in the area of ​​the gap 26 of the loop conductor 22 even when the tag is made smaller. This can suppress the transition of the peak frequency band to the lower frequency side caused by the miniaturization of the inlay 2 accompanying the miniaturization of the tag, and can easily adjust the peak frequency band so that the frequency used is included in the peak frequency band. As a result, the RFID tag 1 of the first embodiment can suppress the deterioration of communication performance even when the tag size is made smaller. In addition, since there is no need to consider the deterioration of communication performance and the RFID tag 1 can be easily made smaller, restrictions on the size of the object to which the tag is attached (for example, the book 30 or the tag 10 (see FIG. 10)) and the attachment position can be reduced, and the versatility of the RFID tag 1 can be improved. In this way, the RFID tag 1 of the first embodiment can suppress a decrease in communication performance even if the tag size is reduced, and can improve versatility.

[0083] In addition, it is advantageous to increase the ratio of the area of ​​the slit 25 to the area of ​​the gap 26 of the loop-shaped conductor 22 in order to achieve the effect that the area of ​​the gap 26 of the loop-shaped conductor 22, which is reduced even when the tag is made smaller, can be compensated for by the slit 25. Specific methods for increasing the area of ​​the slit 25 include increasing the dimension of the slit 25 in the extension direction in the X direction, increasing the width dimension of the slit 25 in the Y direction, and the like.

[0084] Furthermore, in the RFID tag 1 according to the first embodiment, as shown in Fig. 2 etc., the IC chip 21 is disposed at the center position in the longitudinal direction (X direction) and lateral direction (Y direction) of the RFID tag 1. With this configuration, even if a reading operation from the RFID tag 1 is performed from any direction in the X direction or Y direction by a reading device such as an RFID reader 40 illustrated in Fig. 5, it is possible to make it difficult for a difference to occur in the relative positional relationship between the IC chip 21 and the reading device. This makes it possible to make the reading accuracy of information from the RFID tag 1 more uniform.

[0085] In the RFID tag 1 according to the first embodiment, the IC chip 21 is disposed at the center of the RFID tag 1 in the longitudinal direction (X direction) and the transverse direction (Y direction) as described above, so that the size of the loop conductor 22 is also restricted. For example, as shown in FIG. 2, the loop conductor 22 must be disposed on the Y positive direction side or the Y negative direction side (Y negative direction side in the example of FIG. 2) on the inlay 2 with respect to the IC chip 21, and the size in the transverse direction is particularly restricted. Therefore, the loop conductor 22 is strongly affected by the reduction in area of ​​the central gap 26 of the loop conductor 22 that accompanies the miniaturization of the tag. Therefore, in the conductor pattern of the inlay 2 of the RFID tag 1 according to the first embodiment, by providing the slit 25, the effect of suppressing the deterioration of communication performance even when the tag size is miniaturized can be particularly prominently exhibited.

[0086] Furthermore, in the RFID tag 1 of the first embodiment, the slit 25 makes it possible to suppress a decrease in communication performance even if the size of the loop-shaped conductor 22 is reduced, thereby increasing the design freedom when miniaturizing the tag.

[0087] <Modification> Fig. 6 is a plan view of an RFID tag 1A according to a first modified example. Fig. 7 is a plan view of an RFID tag 1B according to a second modified example. Fig. 8 is a plan view of an RFID tag 1C according to a third modified example. Figs. 6 to 8 correspond to Fig. 2, and like Fig. 2, only elements related to the inlay 2 of each of the RFID tags 1A to 1C are illustrated.

[0088] In the above first embodiment, a configuration in which the four strip portions 232A, 232B, 232C, and 232D are provided in the conductor pattern of the inlay 2 has been exemplified, but a configuration in which at least some of the strip portions 232 are not provided may also be used.

[0089] For example, as in the RFID tag 1A of the first modified example shown in Fig. 6, the strip portion 232 may include only a pair of strip portions 232A, 232C provided protruding from the protruding portions 231A, 231C of the pair of rectangular conductors 23A, 23B on the side of one second opposite side portion 222A (see Fig. 2) of the loop-shaped conductor 22, and may be configured not to include other strip portions 232B, 232D. In other words, the conductor pattern of the inlay 2 may be configured such that the pair of rectangular conductors 23A, 23B does not include two strip portions 232B, 232D of the four strip portions 232A to 232D.

[0090] 7, the strip portion 232 may include only a pair of strip portions 232B, 232D protruding from the protruding portions 231B, 231D of the pair of rectangular conductors 23A, 23B on the other second opposite side portion 222B (see FIG. 2) side of the loop conductor 22, and may not include other strip portions 232A, 232C. In other words, the conductor pattern of the inlay 2 may be configured such that the pair of rectangular conductors 23A, 23B does not include two strip portions 232A, 232C of the four strip portions 232A to 232D.

[0091] Also, like the first and second modified examples, the configuration has only two strip parts, but unlike the first and second modified examples, the configuration may have one strip part on the Y positive side and one strip part on the Y negative side. For example, the configuration may have a strip part 232A at the top left and a strip part 232D at the bottom right, a strip part 232B at the bottom left and a strip part 232C at the top right, a strip part 232A at the top left and a strip part 232B at the bottom left, or a strip part 232C at the top right and a strip part 232D at the bottom right. Also, the configuration may have three strip parts without one of the strip parts 232A to 232D, or may have only one of the strip parts 232A to 232D.

[0092] In addition, at least some of the protrusions not provided with strip portions may be omitted. For example, in the first modified example shown in Fig. 6, the conductor pattern of the inlay 2 may be omitted at least one of the two protrusions 231B, 231D not provided with strip portions 232B, 232D. Similarly, in the first modified example shown in Fig. 7, the conductor pattern of the inlay 2 may be omitted at least one of the two protrusions 231A, 231C not provided with strip portions 232A, 232C.

[0093] Furthermore, as in the RFID tag 1C of a third modified example shown in Fig. 8, all of the four strip portions 232A, 232B, 232C, and 232D may not be provided. In this case, at least some of the four protrusions 231A, 231B, 231C, and 231D may not be provided. In other words, the conductor pattern of the inlay 2 may be such that a pair of rectangular conductors 23A and 23B does not include the four strip portions 232A to 232D, or a pair of rectangular conductors 23A and 23B does not include at least some of the four protrusions 231A to 231D.

[0094] For example, the conductor pattern shown in Fig. 8 may be configured without the four protrusions 231A, 231B, 231C, and 231D shown by dotted lines in Fig. 2. In this case, the shape of the pair of rectangular conductors 23A and 23B is a rectangle with a constant width along the X direction.

[0095] Like the RFID tag 1 of the embodiment, the RFID tags 1A, 1B, and 1C of these modified examples are configured to include a loop-shaped conductor 22 and a rectangular conductor 23 formed with the conductive patterns shown in Figures 6, 7, 8, etc., and are therefore able to suppress degradation of communication performance due to the effects of moisture contained in the object to which they are attached and the effects of RFID tags being in close proximity to each other when they are attached to multiple objects to which they are attached.

[0096] Also, in the RFID tags 1A, 1B, and 1C according to the modified examples, the provision of the slit 25 can complement the reduction in the area of ​​the gap 26 of the loop-shaped conductor 22 even when the tag is miniaturized. This makes it possible to suppress the transition of the peak frequency band to the lower frequency side, as in the RFID tag 1 according to the first embodiment, and makes it easy to adjust the peak frequency band so that the frequency in use is included in the peak frequency band. Therefore, the RFID tags 1A, 1B, and 1C according to the modified examples can also be easily miniaturized, so that restrictions on the size of the object to which the tag is attached (for example, a book 30 or a tag 10 (see FIG. 10)) and the attachment position can be reduced, improving the versatility of the RFID tags 1A, 1B, and 1C.

[0097] [Second embodiment] Fig. 9 is a plan view of an RFID tag 1D according to the second embodiment, which corresponds to Fig. 2 of the first embodiment.

[0098] 9, in the RFID tag 1D of the second embodiment, the loop conductor 22 is disposed at the center position in the longitudinal and lateral directions of the RFID tag 1, which is the point where the first virtual line VL and the second virtual line VS intersect. That is, the first opposite sides 221A, 221B are formed so that the end portions on the Y positive side in the extension direction (Y direction) are aligned with the end portions on the Y positive side of the rectangular conductors 23A, 23B, and the end portions on the Y negative side are aligned with the end portions on the Y negative side of the rectangular conductors 23A, 23B.

[0099] The position of the end portion on the Y positive direction side of the second opposite side portion 222A is the same as the position of the end portions on the Y positive direction side of the rectangular conductors 23A and 23B. In other words, the second opposite side portion 222A and the rectangular conductors 23A and 23B are formed so that the ends on the Y positive direction side form a straight line along the X direction. The position of the end portion on the Y negative direction side of the second opposite side portion 222B is the same as the position of the end portions on the Y negative direction side of the rectangular conductors 23A and 23B. In other words, the second opposite side portion 222B and the rectangular conductors 23A and 23B are formed so that the ends on the Y negative direction side form a straight line along the X direction.

[0100] Therefore, the gap 26A of the loop-shaped conductor 22 surrounded by the pair of first opposite sides 221A, 221B and the pair of second opposite sides 222A, 222B is also located at the center position of the RFID tag 1 in the longitudinal and lateral directions.

[0101] The slit 25A is formed in a direction away from the IC chip 21 from the central gap 26A of the loop conductor 22 to one of the rectangular conductors 23B.

[0102] In the RFID tag 1D of the second embodiment, by providing the slit 25A, it is possible to compensate for the reduction in the area of ​​the gap 26A of the loop-shaped conductor 22 even when the tag is miniaturized. This makes it possible to suppress the transition of the peak frequency band to the lower frequency side, and makes it easy to adjust the peak frequency band so that the frequency to be used is included in the peak frequency band. Therefore, since the RFID tag 1D can be easily miniaturized, restrictions on the size of the object to which it is attached (for example, a book 30 or a tag 10 (see FIG. 10)) and the attachment position can be reduced, improving the versatility of the RFID tag 1D.

[0103] Furthermore, in the RFID tag 1D according to the second embodiment, the IC chip 21 is disposed at the center of the RFID tag 1D in the longitudinal direction (X direction) as shown in Fig. 9. This configuration makes it possible to reduce the occurrence of differences in the relative positional relationship between the IC chip 21 and the reading device, regardless of the direction in the X direction from which a reading operation is performed on the RFID tag 1D using a reading device such as the RFID reader 40 illustrated in Fig. 5. This makes it possible to more uniform the accuracy of reading information from the RFID tag 1D.

[0104] In the RFID tag 1D of the second embodiment, the IC chip 21 is arranged shifted from the center position in the short side direction (Y direction) of the RFID tag 1 toward the end on the Y positive side, as shown in Fig. 9. By arranging the IC chip 21 in this way, the dimension in the long side direction (Y direction) of the pair of first opposite side portions 221A, 221B of the loop-shaped conductor 22 becomes longer than that of the first embodiment, so that the ratio of the area of ​​the gap portion 26A of the loop-shaped conductor 22 to the area of ​​the entire tag becomes relatively large. Therefore, the effect of the reduction in the area of ​​the gap portion 26A due to the miniaturization of the tag is also relatively small.

[0105] Therefore, in the second embodiment, the amount of compensation for reducing the area of ​​the gap 26A by the slit 25A may be small. Therefore, when the length of the longitudinal direction (X direction) of the slit 25A is the same as that of the slit 25 in the first embodiment, even if the width dimension of the slit 25A in the Y direction is narrower than that of the first embodiment and the area of ​​the slit 25A is reduced compared to the first embodiment, the effect of suppressing the transition of the peak frequency band to the low frequency side can be achieved similarly to the first embodiment. This improves the degree of freedom in arranging the slit 25A.

[0106] Also, in the RFID tag 1D of the second embodiment, similarly to the first modified example 1A to the third modified example 1C of the first embodiment, at least a part of the strip portions 232 may be omitted.

[0107] [Third embodiment] Fig. 10 is a plan view of a tag 10 according to the third embodiment. In the example of Fig. 10, the tag 10 has the RFID tag 1 of the first embodiment built in.

[0108] Product information 11 regarding the product to which the tag 10 is attached, a barcode 12, and the like are printed on the surface of the tag 10. The product information 11 includes information such as the product name, size, and price, as shown in Fig. 10. Information similar to the product information 11 is recorded in an IC chip 21 installed on an inlay 2 of an RFID tag 1 built into the tag 10. The barcode 12 also includes information corresponding to the product information 11.

[0109] When a reading device such as an RFID reader 40 shown in Fig. 5 is used, product information on the product to which the tag 10 is attached can be read from the internal RFID tag 1. When a reading device such as a barcode reader is used, product information on the product to which the tag 10 is attached can be read from the barcode 12 printed on the surface of the tag 10.

[0110] The barcode 12 may be any identifier including information corresponding to the product information 11, and may be replaced with another identifier such as a two-dimensional code.

[0111] Further, the tag 10 is provided with a perforation 13. The perforation 13 extends in the Y direction at a position where it intersects with the slit 25 of the tag 1. The perforation 13 divides the tag 10 into a base portion 14, in which a hole 16 for passing a string or the like is provided, and a tip portion 15.

[0112] As shown in FIG. 10(A), when base 14 and tip 15 of tag 10 are connected via perforation 13, information can be read from RFID tag 1 embedded in tag 10.

[0113] 10(B), when the tag 10 is torn at the perforation 13 and the tip 15 is cut off from the base 14, the slit 25 of the RFID tag 1 built into the tag 10 is severed at the position of the perforation 13. As a result, the loop conductor 22 of the inlay 2 is also severed, so that the inlay 2 can no longer perform its information transmission function, and information cannot be read from the RFID tag 1.

[0114] In this way, in the tag 10 of the third embodiment, the function of the RFID tag 1 can be completely stopped and the tag can be discarded by cutting the tag 10 into the base portion 14 and the tip portion 15 at the position of the perforation 13 provided at the position intersecting with the slit 25 of the RFID tag 1 built into the tag 10. Therefore, once the tag 10 is cut, it is possible to prevent information from being read from the remaining portion of the IC chip 21 of the RFID tag 1, thereby ensuring security of the RFID tag 1 after it is discarded.

[0115] Note that the perforations 13 need only be provided at a position that intersects at least with the slits 25 of the RFID tag 1, and are not limited to a configuration that extends in a direction (Y direction) perpendicular to the extension direction (X direction) of the slits 25 as in the example of Fig. 10. For example, the perforations 13 may be provided along a direction that is inclined with respect to the X direction or Y direction. Also, the perforations 13 may be curved or broken rather than straight as exemplified in Fig. 10. EXAMPLES

[0116] Next, examples of the present invention will be described in detail.

[0117] <First test setup> Examples 1 to 3 and Comparative Examples 1 to 3 were set as follows, and a first test was carried out to verify the effect on the performance quality of the RFID tag according to the conductor pattern of the inlay 2.

[0118] <Example 1> Two RFID tags 1 shown in Figures 1 and 2 were created with the dimensions of each part shown in Figure 3. In the following explanation, these two tags will be distinguished and referred to as RFID tag 1-1 and RFID tag 1-2.

[0119] Using the RFID tags 1-1 and 1-2 created in this way, we tested the reading performance of RFID tag 1-1 based on the guidelines for measuring and evaluating the performance quality of RFID tags called TIPP (Tagged-Item Performance Protocol) Tagged Item Grading (https: / / www.gs1.org / sites / default / files / docs / epc / Tagged_Item_Test_Methodology.pdf). These guidelines were standardized by an international organization called GS1.

[0120] Fig. 11 is a schematic diagram of the measurement environment of the first test according to Example 1. As shown in Fig. 11, four RFID antennas, namely, a first antenna 51, a second antenna 52, a third antenna 53, and a fourth antenna 54, were installed in an anechoic chamber 50. The measurement environment shown in Fig. 11 is based on the provisions of the above-mentioned guidelines. C50 was applied to the anechoic chamber 50. Tagformance Pro manufactured by Voyantic was used as a measuring device including the first to fourth antennas 51 to 54.

[0121] In the following description, the X1, Y1, and Z1 directions are set to be perpendicular to each other. The Z1 direction is the vertical direction of the anechoic chamber 50. The X1 and Y1 directions are the horizontal directions of the anechoic chamber 50, and are respectively 0 degree and 270 degree directions of the mounting table 55 (see FIG. 12). For convenience of description, the positive side of the Z1 axis may be expressed as the upper side, and the negative side of the Z axis may be expressed as the lower side.

[0122] 11, the first antenna 51, the second antenna 52, the third antenna 53, and the fourth antenna 54 are disposed so as to face a predetermined point in the anechoic chamber 50, and are disposed at positions such that the directions facing the predetermined point are at angles of 0 degrees, 30 degrees, 60 degrees, and 90 degrees, respectively, from the horizontal direction, as shown by the dotted lines in Fig. 11. Furthermore, the first to fourth antennas 51 to 54 are disposed along the same X1Z1 plane.

[0123] The RFID tag 1-1 was placed on the upper surface of a mounting table 55 in an anechoic chamber 50. As shown by the dotted line in Fig. 11, the height of the mounting table 55 was adjusted so that the RFID tag 1-1 was placed at a predetermined point where the facing directions of the first to fourth antennas 51 to 54 intersect. The first to fourth antennas 51 to 54 were installed so that the distances between the RFID tag 1-1 and the predetermined points were all 1 m.

[0124] 11, two pairs of socks were placed in a stack in the Z1 direction above the RFID tag 1-1 placed on the placement stand 55 as an object 60 for preventing the antennas 51-54 from reading information from the RFID tag 1-1. Furthermore, another RFID tag 1-2 was placed above the object 60 (two pairs of socks) as an element for further preventing the antennas 51-54 from reading information from the RFID tag 1-1. The RFID tag 1-2 was placed at a position overlapping the RFID tag 1-1 when viewed in the Z1 direction.

[0125] FIG. 12 is a plan view of the measurement environment shown in FIG. 11. For convenience of illustration, FIG. 12 shows only the first antenna 51, which is arranged in the horizontal direction, among the first to fourth antennas 51 to 54, but the relationship between the other second, third, and fourth antennas 52, 53, and 54 and the orientation of the RFID tag 1-1 is the same. In addition, although not shown in FIG. 12, an object 60 and an RFID tag 1-2 are stacked on the Z1 positive side of the RFID tag 1-1. As shown in FIG. 12, a state in which the RFID tag 1-1 is placed on a placement table 55 with its long side facing the first to fourth antennas 51 to 54 is set as a 0 degree direction, and the angle is set to increase each time the orientation of the long side of the RFID tag 1-1 rotates in the clockwise direction in FIG. 12 around a predetermined point where the RFID tag 1-1 is placed. The mounting base 55 is rotatable around a rotation axis along the Z1 direction passing through a specified point above, and the RFID tag 1-1 placed on the mounting base 55 is configured so that the orientation of its long side can be changed by rotating the mounting base 55.

[0126] Under these conditions, the sensitivity (average output for reading information from the RFID tag 1-1) of the first to fourth antennas 51-54 was measured when the long side of the RFID tag 1-1 was oriented in 10 directions: 0 degree, 30 degree, 60 degree, 120 degree, 150 degree, 180 degree, 210 degree, 240 degree, 300 degree, and 330 degree. In addition, the backscatter (response wave intensity from the RFID tag 1-1) of the first to fourth antennas 51-54 was measured in two directions: 0 degree and 180 degree.

[0127] Using the above measured values, it was determined whether the grade conditions set in TIPP were met. The grade is an evaluation standard for the quality of the reading performance of the RFID tag 1, and multiple types are set. For each grade, a standard value is set for each of the above measured values. A different standard value is set for each grade. When all measured values ​​exceed the standard value, it can be evaluated that the condition of the corresponding grade is met. The grades that can meet the conditions were investigated when two pairs of socks 60 and another RFID tag 1-2 are stacked above the RFID tag 1-1 to be inspected as in this Example 1.

[0128] <Example 2> In Example 2, measurements were performed under the same conditions as in Example 1, except that the object 60 sandwiched between the two RFID tags 1-1 and 1-2 was changed to a pair of socks.

[0129] Using the measurement values ​​obtained by performing measurements similar to those in Example 1, we investigated the grade that can satisfy the conditions when a pair of socks 60 and another RFID tag 1-2 are stacked above the RFID tag 1-1 to be inspected, as in this Example 2.

[0130] <Comparative Example 1> Fig. 13 is a plan view showing the conductor pattern of the RFID tag 101 used in Comparative Examples 1 and 2. Fig. 13 corresponds to Fig. 2, and like Fig. 2, only elements related to the inlay of the RFID tag 101 are shown. In Comparative Example 1, measurements were performed under the same conditions as in Example 1, except that RFID tags 101 having the existing conductor pattern shown in Fig. 13 were used as two tags that sandwiched the object 60, i.e., two pairs of socks, from both sides in the Z1 direction.

[0131] 13, the RFID tag 101 according to the first and second comparative examples has an inlay that includes an IC chip 121, a loop-shaped conductor 122, and an antenna section 123. The inlay has an aluminum sheet attached by dry lamination onto a base material such as a synthetic resin film of polyethylene terephthalate, polypropylene, or the like, to form the loop-shaped conductor 122 and the antenna section 123, and the IC chip 121 is mounted at a specified position.

[0132] 1, 2, etc., the IC chip 121 is similar to the IC chip 21 of the embodiment shown in Fig. 1, Fig. 2, etc., and therefore a description thereof will be omitted. The shape and function of the loop-shaped conductor 122 are also similar to the loop-shaped conductor 22 of the embodiment, and has a pair of short side portions 1221A, 1221B extending in the short direction of the RFID tag 101 and a pair of long side portions 1222A, 1222B extending in the longitudinal direction. The loop-shaped conductor 122 is electrically connected to the IC chip 121 and the antenna portion 123.

[0133] The antenna unit 123 has a structure that realizes impedance conjugate matching with the IC chip 121 for radio waves of a frequency of, for example, about 920 MHz (for example, 860 MHz to 960 MHz, more preferably 915 MHz to 935 MHz). The antenna unit 123 has two conductors (conductors 123A and 123B) as a structure that realizes impedance conjugate matching with the IC chip 121. The conductors 123A and 123B are conductive wiring patterns that are connected to the loop conductor 122 and extend in directions away from the loop conductor 122 (positive and negative directions of the X-axis in the example of FIG. 13). The conductive wiring pattern can be formed by existing methods such as pressing or etching copper foil or aluminum foil, plating, silk screen printing of metal paste, and metal wire, but here it is formed by etching aluminum.

[0134] The conductor portion 123A and the conductor portion 123B are formed symmetrically with respect to a virtual line (corresponding to the first virtual line VL in FIG. 2) passing through approximately the center of the IC chip 121. The virtual line is a line parallel to the XY plane and extending in the Y direction. The virtual line is also a line that approximately bisects the RFID tag 101 into areas in the X direction.

[0135] As shown in FIG. 13, the RFID tag 101 of comparative examples 1 and 2 differs from the RFID tag 1 of the above embodiment in that a pair of conductor portions 123A, 123B of the antenna portion 123 are both connected to one of the long side portions 1222B on the Y positive side of the loop-shaped conductor 122, that the shape of the conductor portions 123A, 123B is not simply rectangular like the rectangular conductor 23 of the above embodiment, but is a more complex shape including wiring extending in a zigzag manner, and that the conductor pattern is not formed line-symmetrically with respect to a second imaginary line VS (see FIG. 2) that passes through approximately the center of the RFID tag 101 in the short side direction (Y direction) and extends in the long side direction (X direction) in a planar view.

[0136] In the RFID tag 101 used in the comparative example, the size of the inlay is the same as that of the RFID tag 1 of the above embodiment. That is, the dimension of the inlay in the longitudinal direction (X direction) shown in Fig. 13 is 70 mm, and the dimension of the inlay 2 in the lateral direction (Y direction) is 14 mm.

[0137] Whether or not the grade conditions set in TIPP were satisfied was determined using each measurement value obtained by performing measurements similar to those in Example 1. In this Comparative Example 1, the test environment is such that an object 60 consisting of two pairs of socks and another RFID tag having a similar structure to the RFID tag 101 are stacked above the RFID tag 101 to be inspected, similar to that in Example 1, so the grade that can satisfy the conditions was investigated when the object 60 sandwiched between the two RFID tags is two pairs of socks, similar to that in Example 1.

[0138] <Comparative Example 2> In Comparative Example 2, measurements were performed under the same conditions as in Example 2, except that RFID tags 101 having the existing conductor pattern shown in Figure 13 were used as the two tags that sandwiched an object 60 (a pair of socks) on both sides in the Z1 direction.

[0139] Whether or not the grade conditions set in TIPP were met was determined using each measurement value obtained by performing measurements similar to those in Example 2. Similar to Example 2, Comparative Example 2 is a test environment in which an object 60 consisting of a pair of socks and another RFID tag having a similar structure to the RFID tag 101 are stacked above the RFID tag 101 to be inspected, and therefore, similar to Example 2, a grade that can meet the conditions was investigated when the object 60 sandwiched between the two RFID tags is a pair of socks.

[0140] <Results of the first test> As a result of the above first test, it was confirmed that both Example 1 and Example 2 satisfied the conditions of the grades M25C and M30E set by TIPP.

[0141] On the other hand, in Comparative Example 1, it was confirmed that the conditions for grade M30E were satisfied, but the conditions for M25C were not satisfied, and in Comparative Example 2, the conditions for grades M25C and M30E were not satisfied.

[0142] Thus, the results of the first experiment showed that even when an object 60 or another RFID tag is stacked above the RFID tag being inspected, the conductor pattern of the RFID tag 1 of this embodiment is less susceptible to the effects of obstructions on communication even under conditions where an object 60 or other tags that obstruct the reading of information by each of the antennas 51 to 54 are present, and degradation of communication performance can be suppressed, compared to the existing conductor pattern of the RFID tag 101 of the comparative example shown in Figure 13.

[0143] <Settings for the second test> Examples 3 to 5 and Comparative Example 3 were set as follows, and a second test was carried out to verify the influence of the conductor pattern of the inlay 2 on the communication performance of the RFID tag.

[0144] <Example 3> 11, a test was conducted to read information from the RFID tag 1-1 using only the first antenna 51, which is arranged in the horizontal direction among the four RFID antennas. The long side of the RFID tag 1-1 placed on the placement stand 55 was oriented in the 0 degree direction described above, and the long side of the RFID tag 1-1 was directly opposed to the first antenna 51.

[0145] Under these conditions, the frequency characteristics of the RFID tag 1-1 were measured. The measurement frequency band of radio waves for wireless communication during the measurement was 800 to 1000 MHz, and the EIRP (Equivalent Isotropically Radiated Power) was 3.28 W. The frequency measurement was performed in a test environment in which only the RFID tag 1-1 to be inspected was placed alone at a predetermined point on the placement table 55, that is, the object 60 and other RFID tags 1-2 were removed from the state shown in FIG. 11. Moreover, in Example 3, unlike Examples 1 and 2, the distance of the first antenna 51 from the placement position of the RFID tag 1-1 on the placement table 55 was made changeable.

[0146] <Example 4> In Example 4, measurements were performed under the same conditions as in Example 3, except that the test environment was such that two pairs of socks 60 and another RFID tag 1-2 were stacked above the RFID tag 1-1 to be inspected, which was placed at a specified point on the mounting table 55, as in Example 1 shown in Figure 11.

[0147] <Example 5> In Example 5, measurements were performed under the same conditions as in Example 3, except that the test environment was such that an object 60 (a pair of socks) and another RFID tag 1-2 were stacked above the RFID tag 1-1 to be inspected, which was placed at a specified point on the mounting table 55, as in Example 2.

[0148] <Comparative Example 3> In Comparative Example 3, measurements were performed under the same conditions as in Example 3, except that the tag to be inspected and placed at a predetermined point on the placement table 55 was an RFID tag 101 having an existing conductor pattern shown in FIG.

[0149] <Results of the second test> FIG. 14 is a diagram showing frequency characteristics of Example 3 and Comparative Example 3 measured in the second test. FIG. 14(A) shows the frequency characteristics of Example 3, and FIG. 14(B) shows the frequency characteristics of Comparative Example 3. The horizontal axis of each of (A) and (B) represents the frequency (MHz) of radio waves for wireless communication, and the vertical axis represents the communicable distance (m) from each RFID tag 1-1, 101 to the first antenna 51. In FIG. 14, the upper and lower limits of the frequency at which the communicable distance is 12.5 m or more in each frequency characteristic are shown by thick dotted lines, and the frequency range between these upper and lower limits is shown by thick dotted arrows A and B. The range of these arrows A and B is the "peak frequency" of each frequency characteristic.

[0150] As shown by the arrow B in Fig. 14(B), in Comparative Example 3, it was confirmed that the area of ​​the gap portion of the loop-shaped conductor 122 was reduced by miniaturizing the tag size, and thus the peak frequency range B moved to the lower frequency side. In contrast, in Example 3, the provision of the slit 25 suppresses the reduction in the area of ​​the gap portion of the loop-shaped conductor 22, and therefore it was confirmed that the peak frequency range A could be maintained on the higher frequency side than in Comparative Example 3, as shown by the arrow A in Fig. 14(A).

[0151] Fig. 15 is a diagram showing the frequency characteristics of Examples 4 and 5 measured in the second test. Fig. 15(A) shows the frequency characteristics of Example 4, and Fig. 15(B) shows the frequency characteristics of Example 5. The horizontal and vertical axes in each of Figs. (A) and (B) are generally the same as in Fig. 14.

[0152] In Fig. 15, the location of the predetermined frequency of 910 MHz included in the UHF band is indicated by a thick dotted line. As shown in Fig. 15, it was confirmed that the peak of the frequency characteristics can be maintained at around 910 MHz even when an object 60 or another RFID tag 1-2 is stacked above the RFID tag 1-1 to be inspected. This shows that even under conditions where an object 60 or another tag 1-2 that blocks the antenna 51 from reading information from the RFID tag 1-1 is present, the communication is less susceptible to the effects of these obstructions, and a decrease in communication performance can be suppressed.

[0153] The present embodiment has been described above with reference to specific examples. However, the present disclosure is not limited to these specific examples. Any design modifications made by a person skilled in the art to these specific examples are also included within the scope of the present disclosure as long as they have the features of the present disclosure. The elements of each of the above-mentioned specific examples and their arrangements, conditions, shapes, etc. are not limited to those exemplified and can be changed as appropriate. The combination of each of the elements of each of the above-mentioned specific examples can be changed as appropriate as long as no technical contradiction occurs. [Explanation of symbols]

[0154] 1, 1A, 1B, 1C, 1D RFID Tags 10 Tag 13 Perforation 21 IC chip 22 Loop conductor 221A, 221B A pair of first opposing sides 222A, 222B A pair of second opposite sides 23A, 23B A pair of rectangular conductors 231A, 231B, 231C, 231D protrusion 232A, 232B, 232C, 232D Strips 25 Slit 26. Gaps in loop conductor

Claims

1. A rectangular RFID tag, An IC chip in which identification information is recorded; a loop-shaped conductor formed in an annular shape and connected to the IC chip; A pair of rectangular conductors extending from the loop conductor on both sides of the rectangular shape in the longitudinal direction and formed into a rectangular shape; a slit formed in a direction away from the IC chip from a central gap of the loop conductor to one of the pair of rectangular conductors; An RFID tag comprising:

2. The IC chip is disposed at the center of the RFID tag in the longitudinal direction. The RFID tag of claim 1 .

3. The IC chip is disposed at the center of the RFID tag in the short side direction. The RFID tag of claim 2.

4. Each of the pair of rectangular conductors is provided with a protruding portion protruding outward in the short-side direction from the loop conductor from at least one of both ends of the rectangular shape in the short-side direction, The tape portion is provided so as to protrude from the protruding portion toward the center side in the longitudinal direction and is formed in a strip shape. The RFID tag according to any one of claims 1 to 3.

5. the loop-shaped conductor has a pair of first opposite side portions extending in the short side direction and arranged opposite to each other in the long side direction, and a pair of second opposite side portions extending in the long side direction and arranged opposite to each other in the short side direction, The strip portion includes a pair of strip portions provided on one side of the pair of second opposite sides so as to protrude from the protruding portions of the pair of rectangular conductors. The RFID tag according to claim 4.

6. The strip portions include another pair of strip portions provided on the other side of the pair of second opposite sides so as to protrude from the protruding portions of the pair of rectangular conductors. The RFID tag according to claim 5 .

7. the strip portion is formed so as not to overlap a portion of the loop-shaped conductor on which the IC chip is disposed when viewed from the short-side direction; The RFID tag according to claim 4.

8. A tag to which a rectangular RFID tag is attached, The RFID tag comprises: An IC chip in which identification information is recorded; a loop-shaped conductor formed in an annular shape and connected to the IC chip; A pair of rectangular conductors extending from the loop conductor on both sides of the rectangular shape in the longitudinal direction and formed into a rectangular shape; a slit formed in a direction away from the IC chip from a central gap of the loop conductor to one of the pair of rectangular conductors; having A perforation is provided at a position of the RFID tag that intersects with the slit. Hang tag.

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