RFID tag

Abstract

To provide an RFID tag that is equipped with a sensor such as a strain sensor and that can ensure good communication performance even when the RFID tag is attached to a metallic object.SOLUTION: An RFID tag 1 is attached to a metallic object 100, and has an inlay 20. The inlay 20 includes a base material 21 made of a film, an IC chip 22 that is disposed on the base material 21, and an antenna 23 that is disposed on the base material 21 and is connected to the IC chip 22. The IC chip 22 integrally has a condition detection sensor for detecting the condition of the object 100. The RFID tag 1 further has a non-metallic member (first housing member 11) that is disposed between the antenna 23 and the object 100. The IC chip 22 comes into contact with the object 100. The condition detection sensor includes a strain sensor for detecting strain of the metallic object 100.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to an RFID (Radio Frequency Identification) tag.

Background Art

[0002] Patent Document 1 discloses a passive RFID tag including a strain sensor. In Patent Document 1, a circuit for an RFID tag is manufactured as a single chip (integrated circuit) including a strain sensor, a first sub-circuit configured to acquire a measurement value of the strain sensor, and a second sub-circuit configured to wirelessly transmit the acquired measurement value to an RFID reader. That is, in Patent Document 1, a strain sensor is incorporated in an IC chip constituting the RFID tag.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Regarding the RFID tag disclosed in Patent Document 1, the IC chip itself incorporating the strain sensor must be attached to the object (object to be measured) for strain measurement. However, when the object is made of metal, due to radio wave interference caused by the metal, the transmission and reception function (for example, communication distance) of the RFID tag deteriorates, or the RFID tag becomes unable to transmit and receive.

[0005] The present invention has been made in view of such a situation, and an object thereof is to provide an RFID tag including a sensor such as a strain sensor, which can ensure good communication performance even when attached to a metal object.

Means for Solving the Problem

[0006] Therefore, in the first aspect of the present invention, the RFID tag is attached to a metal object and has an inlay. The inlay includes a base material made of a film, an IC chip disposed on the base material, and an antenna disposed on the base material and connected to the IC chip. The IC chip integrally has a state detection sensor for detecting the state of the object. The RFID tag further has a non-metallic member disposed between the antenna and the object. The IC chip contacts the object.

[0007] In the second aspect of the present invention, the RFID tag is attached to a metal object and has an inlay. The inlay includes a base material made of a film, an IC chip disposed on the base material, an antenna disposed on the base material and connected to the IC chip, and a state detection sensor disposed on the base material, connected to the IC chip, and for detecting the state of the object. The RFID tag further has a non-metallic member disposed between the antenna and the object. The state detection sensor contacts the object.

Advantages of the Invention

[0008] According to the first aspect of the present invention, for an RFID tag having an IC chip with a built-in state detection sensor that contacts a metal object, good communication performance can be ensured even when the tag is attached to the object.

[0009] According to the second aspect of the present invention, for an RFID tag having a state detection sensor that contacts a metal object, good communication performance can be ensured even when the tag is attached to the object.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0012] FIG. 1 is a perspective view of the RFID tag 1 in the first embodiment of the present invention. Specifically, FIG. 1(A) is a perspective view of the RFID tag 1 as seen obliquely from above in a state where the first housing member 11 constituting the RFID tag 1 is located on the lower side and the second housing member 12 is located on the upper side. FIG. 1(B) is a perspective view of the RFID tag 1 as seen obliquely from above in a state where the second housing member 12 is located on the lower side and the first housing member 11 is located on the upper side.

[0013] FIG. 2 is a longitudinal sectional view of the RFID tag 1 and corresponds to the I-I sectional view of FIG. 1(A).

[0014] FIG. 3 is a diagram showing the RFID tag 1 attached to the metal object 100, corresponding to FIG. 2. Here, the object 100 can be a member constituting a civil engineering structure or a building structure. As the object 100, for example, it can be any of a steel frame, a metal panel, a metal wire rod, a bolt, and a reinforcing bar. That is, the object 100 can include those made of iron.

[0015] The RFID tag 1 in the present embodiment is a so-called passive RFID tag, and is configured to be able to perform wireless communication (data transmission and reception) with an RFID reader / writer (not shown) in a high frequency band such as the UHF band (860 - 960 MHz band). The RFID tag 1 is, for example, in the shape of a rectangular parallelepiped. In the present embodiment, each dimension of the RFID tag 1 is, for example, as follows (see FIG. 1(A)). Vertical (length in the longitudinal direction, long side) L1: 60 - 150 mm Horizontal (length in the short - hand direction, short side) L2: 20 - 60 mm Height (thickness) L3: 40 mm or less However, each dimension of the RFID tag 1 is not limited to the above.

[0016] As shown in FIGS. 1 to 3, the RFID tag 1 includes a housing 10 forming its outer shell and an inlay 20 housed in the housing 10. The housing 10 includes a first housing member 11 and a second housing member 12. The inlay 20 is housed in the housing 10 by sandwiching the inlay 20 from both sides by the first housing member 11 and the second housing member 12.

[0017] FIG. 4 is a diagram showing a schematic configuration of the inlay 20. Specifically, FIG. 4(A) is a plan view of the inlay 20. FIG. 4(B) is a front view of the inlay 20 and is a view taken along the arrow II in FIG. 4(A).

[0018] As shown in FIG. 4, the inlay 20 includes a rectangular sheet-shaped base material 21, an IC (Integrated Circuit) chip 22 disposed on one surface 21a of the base material 21, and an antenna 23. The base material 21 is made of a resin film such as PET (polyethylene terephthalate) and has flexibility. The thickness of the base material 21 is preferably, for example, 0.5 mm or less.

[0019] The IC chip 22 is disposed at the central portion of the rectangular sheet-shaped base material 21. The antenna 23 is a so-called dipole antenna and is symmetrically disposed on both sides in the longitudinal direction of the base material 21 with the IC chip 22 interposed therebetween. The antenna 23 is electrically connected to the IC chip 22. The antenna 23 is used for wireless communication (data transmission and reception) with the above-described RFID reader / writer.

[0020] The IC chip 22 incorporates a state detection sensor (not shown) for detecting the state of the object 100. That is, the IC chip 22 integrally has this state detection sensor. In the present embodiment, a strain sensor for detecting the strain of the object 100 is incorporated in the IC chip 22 as this state detection sensor. In addition to or instead of the strain sensor, a temperature sensor for detecting the temperature of the object 100 may be incorporated in the IC chip 22 as this state detection sensor.

[0021] The antenna 23 can transmit data (strain data and / or temperature data) acquired by the state detection sensor (strain sensor and / or temperature sensor) of the IC chip 22 to the above-described RFID reader / writer.

[0022] The IC chip 22 can be manufactured, for example, by providing an electric circuit on a silicon wafer. The antenna 23 can be formed on one surface 21a of the base material 21 by a manufacturing method such as an etching method or a printed antenna method.

[0023] Returning to FIGS. 1 to 3, the first housing member 11 and the second housing member 12 are each formed of a non-metallic material. In other words, the first housing member 11 and the second housing member 12 are each non-metallic members. Examples of such non-metallic materials include hard plastic materials and foamed foam materials. Incidentally, the first housing member 11 and the second housing member 12 each have lower conductivity than the metal object 100.

[0024] FIG. 5 is a diagram showing a schematic configuration of the first housing member 11. Specifically, FIG. 5(A) is a perspective view of the first housing member 11. FIG. 5(B) is a front view of the first housing member 11. FIG. 5(C) is a plan view of the first housing member 11 and corresponds to the view taken along arrow III in FIG. 5(B). Here, for convenience of explanation, as shown in FIG. 5(A), the up-down, front-back, and left-right directions are defined and described.

[0025] The first housing member 11 has a rectangular parallelepiped shape with the left-right direction as the longitudinal direction and is a solid member in this embodiment. The first housing member 11 has an upper surface 31, a lower surface 32, a front surface 33, a rear surface 34, a left side surface 35, and a right side surface 36.

[0026] The following surface 32 is a flat surface and serves as a contact surface that contacts the object 100. The upper surface 31 has a concave portion 31a that smoothly curves (curves so as to be smoothly convex downward) toward the lower surface 32 at the central portion in the longitudinal direction of the first housing member 11, and planar portions 31b that are symmetrically arranged on both sides in the longitudinal direction of the first housing member 11 with the concave portion 31a interposed therebetween and extend parallel to the lower surface 32. The upper surface 31 serves as an installation surface on which the inlay 20 is installed. Here, in the first housing member 11, the region P between the planar portion 31b of the upper surface 31 (the installation surface of the inlay 20) and the lower surface 32 (the contact surface with the object 100) serves as the "non-metallic member disposed between the antenna and the object" of the present invention. In the present embodiment, the thickness t1 of this region P is within the range of 10 to 30 mm. Here, by setting the thickness t1 of the region P to 10 mm or more, even if the RFID tag 1 is attached to the metal object 100, a sufficient communication distance of the RFID tag 1 can be ensured. Also, by setting the thickness t1 of the region P to 30 mm or less, the increase in size of the RFID tag 1 can be suppressed.

[0027] A through hole 37 is formed in the first housing member 11 so as to penetrate the bottom of the concave portion 31a of the upper surface 31 (the installation surface of the inlay 20) and the lower surface 32 (the contact surface with the object 100). When the inlay 20 is installed on the upper surface 31 (the installation surface of the inlay 20), the IC chip 22 can be inserted into this through hole 37. In a state where the IC chip 22 is inserted into the through hole 37, it is preferable that the exposed surface of the IC chip 22 to the outside and the lower surface 32 (the contact surface with the object 100) of the first housing member 11 are substantially flush (see FIG. 2). Also, in a state where the IC chip 22 is inserted into the through hole 37, it is preferable that a clearance for suppressing mutual contact is formed between the inner peripheral surface of the through hole 37 and the IC chip 22. By forming such a clearance, it is possible to suppress the influence of the first housing member 11 on the sensing by the state detection sensor incorporated in the IC chip 22.

[0028] As shown in FIGS. 1 to 3, the second housing member 12 includes a rectangular plate-shaped main body portion 41 and a convex portion 42 that smoothly curves and protrudes from the main body portion 41. The convex portion 42 is shaped to fit into the concave portion 31a of the first housing member 11. The second housing member 12 can cooperate with the first housing member 11 to contribute to the strength and shape retention of the RFID tag 1.

[0029] FIGS. 6(A) to (G) are diagrams showing an example of a method for assembling the RFID tag 1. Here, for convenience of explanation, as shown in FIG. 6(A), the up-down, front-back, and left-right directions are defined and described.

[0030] First, the first housing member 11 is arranged in the orientation shown in FIG. 6(A). Next, as shown in FIG. 6(B), with one surface 21a of the base material 21 of the inlay 20 facing downward (that is, with the IC chip 22 and the antenna 23 on the base material 21 facing downward), the inlay 20 is installed on the upper surface 31 (the installation surface of the inlay 20) of the first housing member 11. At the time of this installation, most of the antenna 23 of the inlay 20 contacts the flat portion 31b of the upper surface 31 (the installation surface of the inlay 20) of the first housing member 11. Also, the IC chip 22 is inserted into the through hole 37 of the first housing member 11. Note that FIG. 6(B) shows the other surface 21b (the surface on the back side of the one surface 21a) of the base material 21. Since the base material 21 has flexibility, it can be deformed to well follow the shape of the smoothly curved upper surface 31 (the installation surface of the inlay 20) of the first housing member 11. That is, the inlay 20 assumes a three-dimensional shape (a three-dimensional shape) along the shape of the smoothly curved upper surface 31 (the installation surface of the inlay 20) of the first housing member 11. Note that the upper surface 31 (the installation surface of the inlay 20) of the first housing member 11 is not limited to a curved surface, and may be a bent surface as long as breakage of the base material 21 constituting the inlay 20 to be installed and disconnection of the antenna 23 do not occur.

[0031] Next, as shown in FIG. 6(c), with the convex portion 42 of the second housing member 12 facing downward, the convex portion 42 is fitted into the concave portion 31a on the upper surface 31 of the first housing member 11, and the second housing member 12 is installed on the first housing member such that the second housing member 12 covers the upper surface 31 of the first housing member 11 and the inlay 20 from above. In this way, the RFID tag 1 can be assembled. Note that the method of assembling the RFID tag 1 is not limited to the above.

[0032] As shown in FIG. 3, for the RFID tag 1, the lower surface 32 (contact surface with the object 100) of the first housing member 11 is adhered to the surface of the metal object 100 with an adhesive. At this time, the exposed surface of the IC chip 22, which is substantially flush with the lower surface 32 (contact surface with the object 100) of the first housing member 11, is also adhered to the surface of the metal object 100 with an adhesive. That is, when the RFID tag 1 is directly attached to the metal object 100, the IC chip 22 of the RFID tag 1 is also directly attached to the metal object 100. Thereby, the strain and / or temperature of the metal object 100 can be directly and favorably detected by the sensor incorporated in the IC chip 22.

[0033] Also, in the present embodiment, in order to make the maximum distance D1 between the antenna 23 and the object 100 be in the range of 10 mm or more and 30 mm or less when the RFID tag 1 is attached to the metal object 100, the thickness t1 of the region P is defined to be in the range of 10 to 30 mm. Thereby, when the RFID tag 1 is attached to the metal object 100, the communication distance of the RFID tag 1 can be sufficiently ensured. Here, in the present embodiment, the above-described maximum distance D1 corresponds to the thickness t1 of the above-described region P.

[0034] FIG. 7 is a perspective view of the RFID tag 1 in a modified example of the present embodiment, and corresponds to FIG. 1(b) described above. In this modified example, as shown in FIG. 7, by forming a recess 39 in the first housing member 11, the first housing member 11 has a hollowed-out shape. Note that this hollowed-out shape is not limited to that shown in FIG. 7. By making the first housing member 11 have a hollowed-out shape in this way, the weight of the first housing member 11 can be reduced, and the manufacturing cost can also be suppressed.

[0035] According to this embodiment, the RFID tag 1 is attached to a metal object 100 and has an inlay 20. The inlay 20 includes a base material 21 made of a film, an IC chip 22 disposed on the base material 21, and an antenna 23 disposed on the base material 21 and connected to the IC chip 22. The IC chip 22 integrally has a state detection sensor for detecting the state of the object 100. The RFID tag 1 further has a non-metal member (first housing member 11) disposed between the antenna 23 and the object 100. The IC chip 22 contacts the object 100. Thereby, for the RFID tag 1 having the IC chip 22 with the state detection sensor built therein that contacts the metal object 100, good communication performance can be ensured even when it is attached to the object 100. Also, even while the IC chip 22 contacts the object 100, the distances (t1, D1) between the antenna 23 and the object 100 can be ensured.

[0036] Also according to this embodiment, the above-described state detection sensor includes a strain sensor for detecting the strain of the metal object 100. Thereby, the strain of the metal object 100 can be directly and satisfactorily detected.

[0037] Also according to this embodiment, the above-described state detection sensor further includes a temperature sensor for detecting the temperature of the metal object 100. Thereby, the temperature of the metal object 100 can be directly and satisfactorily detected.

[0038] According to the present embodiment, a part of the housing 10 that at least partially covers the inlay 20 functions as a non-metallic member disposed between the antenna 23 and the metallic object 100. Thereby, good communication performance of the RFID tag 1 can be ensured with a simple configuration.

[0039] According to the present embodiment, in a state where the RFID tag 1 is attached to the metallic object 100, the thickness t1 of the non-metallic member is defined such that the maximum distance D1 between the antenna 23 and the object 100 is within a range of 10 mm or more and 30 mm or less. Thereby, in a state where the RFID tag 1 is attached to the metallic object 100, the communication distance of the RFID tag 1 can be sufficiently ensured and the size increase of the RFID tag 1 can be suppressed.

[0040] According to the present embodiment, the metallic object 100 is a member constituting a civil engineering structure or an architectural structure. Using the RFID tag 1, the strain and / or temperature of such a member can be directly and satisfactorily detected.

[0041] Next, a second embodiment of the present embodiment will be described with reference to FIG. 8. FIG. 8 is a diagram showing a schematic configuration of the first housing member 11' in the present embodiment. Specifically, FIG. 8(A) is a perspective view of the first housing member 11'. FIG. 8(I) is a plan view of the first housing member 11' and corresponds to a view taken along arrow IV in FIG. 8(A). Here, for convenience of explanation, as shown in FIG. 8(A), the up-down, front-back, and left-right directions will be defined and described. Differences from the above-described first embodiment will be described.

[0042] In the present embodiment, the upper surface 31 of the first housing member 11' has a recessed portion 31c that is rectangular in a top view and recessed, and the above-described concave portion 31a and flat portion 31b are formed in the recessed portion 31c. Then, these concave portion 31a and flat portion 31b serve as the installation surface of the inlay 20.

[0043] In this embodiment, the through-hole 37' that penetrates the bottom of the concave portion 31a and the lower surface 32 of the first housing member 11' has an elongated shape extending in the front-rear direction. The length of the through-hole 37' in the front-rear direction is equal to the length (width) of the inlay 20 in the front-rear direction, in other words, equal to the length (width) of the base material 21 in the front-rear direction. When the inlay 20 is installed on the concave portion 31a and the flat portion 31b (the installation surface of the inlay 20) of the first housing member 11', the IC chip 22 can be inserted into this through-hole 37'. In a state where the IC chip 22 is inserted into this through-hole 37', it is preferable that the exposed surface of the IC chip 22 to the outside and the lower surface 32 (the contact surface with the object 100) of the first housing member 11' are substantially flush. Also, in a state where the IC chip 22 is inserted into this through-hole 37', it is preferable that a clearance for suppressing mutual contact is formed between the inner peripheral surface of the through-hole 37' and the IC chip 22. By forming such a clearance, it is possible to suppress the influence of the first housing member 11' on the sensing by the state detection sensor built in the IC chip 22.

[0044] In addition, in this embodiment, the first housing member 11' is a solid member. However, in addition, similar to the modification of the first embodiment shown in FIG. 7 described above, the first housing member 11' may have a hollowed-out shape.

[0045] Next, the third embodiment of this embodiment will be described with reference to FIG. 9. FIG. 9 is a view showing the RFID tag 1 attached to the metal object 100 in this embodiment and is a longitudinal sectional view of the RFID tag 1. Here, for the sake of convenience of explanation, as shown in FIG. 9, the up-down and left-right directions will be defined and described. Differences from the above-described first and second embodiments will be described.

[0046] In this embodiment, with one surface 21a of the base material 21 of the inlay 20 facing upward (that is, with the IC chip 22 and the antenna 23 on the base material 21 facing upward), the inlay 20 is installed on the concave portion 31a and the flat portion 31b (the installation surface of the inlay 20) of the first housing members 11, 11'. At the time of this installation, most of the antenna 23 of the inlay 20 is located on the flat portion 31b of the first housing members 11, 11'. Also, the peripheral base material 21 can be inserted into the through holes 37, 37' of the first housing members 11, 11' together with the IC chip 22. That is, in the through holes 37, 37', the base material 21 can be located below the IC chip 22. In this embodiment, it is preferable that a clearance for suppressing mutual contact is formed between the convex portion 42 of the second housing member 12 and the IC chip 22. By forming such a clearance, it is possible to suppress the sensing by the state detection sensor incorporated in the IC chip 22 from being affected by the second housing member 12.

[0047] Particularly according to this embodiment, the IC chip 22 contacts the metal object 100 via the base material 21. If the thickness of the base material 21 is, for example, 0.5 mm or less, even if the base material 21 is interposed between the IC chip 22 and the metal object 100, there is no problem in detecting the strain and / or temperature of the metal object 100. Also, the base material 21 can serve as a protective material from the outside for the IC chip 22.

[0048] Also according to this embodiment, the base material 21 is interposed between the antenna 23 and the first housing members 11, 11'. Thereby, the base material 21 can serve as a protective material from the outside for the antenna 23.

[0049] Next, a fourth embodiment of this embodiment will be described with reference to FIG. 10. FIG. 10 is a view showing the RFID tag 1 attached to the metal object 100 in this embodiment, and is a longitudinal sectional view of the RFID tag 1. Here, for convenience of explanation, as shown in FIG. 10, the up-down and left-right directions are defined and described. The differences from the above-described first and second embodiments will be described.

[0050] In the present embodiment, regarding the installation surface of the inlay 20 on the upper surface 31 of the first housing members 11, 11', the flat portion 31b is omitted and it is composed only of the concave portion 31a. In the present embodiment, the thickness t2 of the first housing members 11, 11' can be about 40 to 50 mm at maximum.

[0051] In the present embodiment, the inlay 20 is installed on the concave portion 31a (the installation surface of the inlay 20) of the first housing members 11, 11' with one surface 21a of the base material 21 of the inlay 20 facing downward (that is, with the IC chip 22 and the antenna 23 on the base material 21 facing downward). However, in addition to this, similar to the above-described third embodiment, the inlay 20 may be installed on the concave portion 31a (the installation surface of the inlay 20) of the first housing members 11, 11' with one surface 21a of the base material 21 of the inlay 20 facing upward (that is, with the IC chip 22 and the antenna 23 on the base material 21 facing upward).

[0052] Next, the fifth embodiment of the present embodiment will be described with reference to FIG. 11. FIG. 11 is a diagram showing a schematic configuration of the inlay 20' and is a plan view of the inlay 20'. The differences from the above-described first to fourth embodiments will be described.

[0053] In the above-described first to fourth embodiments, the state detection sensor was built in the IC chip 22, but in the present embodiment, the state detection sensor 25 is arranged on one surface 21a of the base material 21 and is electrically connected to the IC chip 22. In addition, similar to the IC chip 22, it is preferable that the state detection sensor 25 is arranged at the center of the rectangular sheet-like base material 21.

[0054] In this embodiment, the state detection sensor 25 includes a strain sensor that detects the strain of the metal object 100. However, in addition to or instead of the strain sensor, the state detection sensor 25 may include a temperature sensor that detects the temperature of the object 100.

[0055] The antenna 23 can transmit the data (strain data and / or temperature data) acquired by the state detection sensor 25 (strain sensor and / or temperature sensor) to the above-described RFID reader / writer.

[0056] In this embodiment, the state detection sensor 25 is inserted into the through holes 37, 37' of the first housing members 11, 11'. And in this embodiment, the state detection sensor 25 directly contacts the metal object 100 or indirectly contacts it via the base material 21.

[0057] Note that FIG. 3 described above shows an example in which the IC chip 22 incorporating the state detection sensor directly contacts the metal object 100. However, this embodiment can correspond to the case where the IC chip 22 is replaced with the state detection sensor 25 in FIG. 3. Also, FIG. 9 described above shows an example in which the IC chip 22 incorporating the state detection sensor indirectly contacts the metal object 100 via the base material 21. However, this embodiment can correspond to the case where the IC chip 22 is replaced with the state detection sensor 25 in FIG. 9.

[0058] In particular, according to the present embodiment, the inlay 20' includes a base material 21 made of a film, an IC chip 22 disposed on the base material 21, an antenna 23 disposed on the base material 21 and connected to the IC chip 22, and a state detection sensor 25 disposed on the base material 21, connected to the IC chip 22, and detecting the state of the object 100. The RFID tag 1 further includes non-metal members (the first housing members 11, 11') disposed between the antenna 23 and the object 100. The state detection sensor 25 contacts the object 100. Thereby, for the RFID tag 1 having the state detection sensor 25 that contacts the metal object 100, good communication performance can be ensured even when it is attached to the object 100.

[0059] Also according to the present embodiment, the state detection sensor 25 may contact the metal object 100 via the base material 21. If the thickness of the base material 21 is, for example, 0.5 mm or less, there is no problem in detecting the strain and / or temperature of the metal object 100 even if the base material 21 is interposed between the state detection sensor 25 and the metal object 100. Further, the base material 21 can serve as a protective material from the outside for the state detection sensor 25.

[0060] In the above-described first to fifth embodiments, a sheet-like member made of a soft magnetic material may be interposed between the antenna 23 and the first housing members 11, 11'. An example of this soft magnetic material may be a composite material made of soft magnetic powder or soft magnetic flakes and plastic or rubber. The occurrence of communication failure of the RFID tag 1 can be further suppressed by the sheet-like member made of this soft magnetic material. The sheet-like member made of this soft magnetic material may be attached to the inlays 20, 20' prior to the installation of the inlays 20, 20' on the first housing members 11, 11'.

[0061] In the above-described first to fifth embodiments, the base material 21 is formed of a film. However, the base material 21 may be formed of paper. Further, as the base material 21, a hard epoxy substrate formed in a three-dimensional shape may be used. However, by forming the base material 21 of a film, the inlays 20, 20' can be manufactured at a lower cost than when the base material 21 is formed of a hard epoxy substrate.

[0062] Regarding the above-described metal object 100, at least a part of the object 100 may be made of metal. Therefore, as the object 100, for example, a member made of reinforced concrete (RC) may also be included.

[0063] The illustrated embodiments are merely illustrative of the present invention, and it goes without saying that the present invention includes various improvements and modifications made by those skilled in the art within the scope of the claims in addition to those directly shown by the described embodiments.

Explanation of Reference Numerals

[0064] 1 RFID tag 10 Housing 11, 11' First housing member 12 Second housing member 20, 20' Inlay 21 Base material 21a One surface 21b The other surface 22 IC chip 23 Antenna 25 State detection sensor 31 Upper surface 31a Concave portion 31b Flat portion 31c Depression 32 Lower surface 33 Front surface 34 Rear surface 35 Left side surface 36 Right side surface 37, 37' Through hole 39 Recess 41 Body portion 42 Convex portion 100 Object t1, t2 Thickness D1 Maximum distance P Region

Claims

1. An RFID tag that is attached to a metallic object and has an inlay, wherein the inlay comprises a base material made of a film, an IC chip disposed on the base material, an antenna disposed on the base material and connected to the IC chip, and is provided with the IC chip integrally has a state detection sensor for detecting the state of the object, the RFID tag further has a non-metallic member disposed between the antenna and the object, the RFID tag in which the IC chip contacts the object.

2. The RFID tag according to claim 1, wherein the IC chip contacts the object via the base material.

3. An RFID tag that is attached to a metallic object and has an inlay, wherein the inlay comprises a base material made of a film, an IC chip disposed on the base material, an antenna disposed on the base material and connected to the IC chip, a state detection sensor disposed on the base material, connected to the IC chip, and for detecting the state of the object, and is provided with the RFID tag further has a non-metallic member disposed between the antenna and the object, the RFID tag in which the state detection sensor contacts the object.

4. The RFID tag according to claim 3, wherein the state detection sensor contacts the object via the base material.

5. The RFID tag according to any one of claims 1 to 4, wherein the state detection sensor includes a strain sensor for detecting strain of the object.

6. The RFID tag according to claim 5, wherein the state detection sensor further includes a temperature sensor for detecting the temperature of the object.

7. The RFID tag according to any one of claims 1 to 4, wherein a part of a housing that at least partially covers the inlay functions as the non-metallic member.

8. The thickness of the non-metallic member is defined such that, when the RFID tag is attached to the object, the maximum distance between the antenna and the object is in the range of 10 mm or more and 30 mm or less. The RFID tag according to any one of claims 1 to 4.

9. The object is a member constituting a civil engineering structure or a building structure. The RFID tag according to any one of claims 1 to 4.

Images