Article with RFID tag

Abstract

To facilitate manufacture of an article with an RFID tag which uses a spiral boost antenna as a boost antenna for the RFID tag.SOLUTION: An article 10 with an RFID tag 20 includes: a shaft including component 11 which at least includes a shaft part 11a; and a mounting head part 12 mounted on a root side of the shaft part 11a in the shaft including component 11. The mounting head part 12 includes: the RFID tag; a spiral boost antenna 21 which is an antenna for the RFID tag 20, and which extends from a proximal side of the shaft including component 11 in the mounting head part 12 to a distal side of the shaft including component 11 in the mounting head part 12; and a pedestal part 15 which is a member extending inside the boost antenna 21, and which has a tag installation surface 16 in which the RFID tag 20 is installed. The tag installation surface 16 is positioned in the vicinity of an end of the distal side of the boost antenna 21 outside a range X between both ends of the boost antenna 21 or inside an end part on the distal side of the boost antenna 21 within the range X between both ends.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to RFID (Radio Frequency Identification) and the like. [Background technology]

[0002] RFID is a general term for short-distance communication that uses induction electromagnetic fields or radio waves to read and write data in semiconductor memory without contact. An RFID system that uses RFID consists of, for example, an RFID tag, a reader / writer, and a higher-level device that controls them. An RFID tag is an IC chip with a resonant circuit that acts as an antenna connected to it.

[0003] Patent Document 1 describes a wearable member with an RFID tag. This wearable member with an RFID tag includes an axial part having an insert part and a base part, an RFID tag for transmitting and receiving radio waves, a boost antenna for boosting the radio waves transmitted to and received from the RFID tag, and a resin head part in which at least the front surface side of the base part is molded to seal the RFID tag and the boost antenna. The boost antenna is a coil spring-shaped conductor with the RFID tag located inside. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2022-044984 A Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, in the RFID tag-equipped wearing member described in Patent Document 1, the RFID tag is disposed inside the spiral boost antenna, away from the end of the boost antenna. In this case, while the magnetic field coupling between the RFID tag and the boost antenna is strong, it is not easy to dispose the RFID tag inside the boost antenna, and there is a risk of reduced manufacturing efficiency. Specifically, when the RFID tag is installed after the boost antenna is installed, it is not easy to install the RFID tag, and when the boost antenna is installed after the RFID tag is installed, it is not easy to install the boost antenna.

[0006] The present invention has been made in consideration of the above circumstances, and has an object to facilitate the manufacture of RFID tagged articles that use a spiral boost antenna as a boost antenna for an RFID tag. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, the first invention is an RFID-tagged article comprising an axle-equipped part having at least a shaft portion, and a mounting head attached to the base side of the shaft portion of the axle-equipped part, the mounting head comprising an RFID tag, an antenna for the RFID tag, a spiral boost antenna extending from the proximal side of the axle-equipped part in the mounting head to the distal side of the axle-equipped part in the mounting head, and a base portion which is a member extending inside the boost antenna and has a tag mounting surface on which the RFID tag is mounted, the tag mounting surface being located near the distal end of the boost antenna outside the range between both ends of the boost antenna, or inside the distal end of the boost antenna within the range between the two ends.

[0008] A second aspect of the present invention is the antenna device according to the first aspect of the present invention, further comprising a surrounding portion that is integrated with the base portion and surrounds an outer circumferential surface of the boost antenna.

[0009] In a third aspect of the present invention, in the first aspect of the present invention, the boost antenna is wound around the base portion.

[0010] A fourth invention is based on the first invention, in which the base portion has a columnar portion with a spiral groove formed on its outer peripheral surface, and the boost antenna is wound around the columnar portion while being fitted into the spiral groove.

[0011] The fifth invention is related to the first invention, wherein the base portion has a first columnar portion arranged on the proximal side and a second columnar portion integrated with the distal end surface of the first columnar portion and around which a boost antenna is wound, and the first columnar portion has a corner on its outer peripheral surface or has a hole with a corner on its inner peripheral surface.

[0012] A sixth aspect of the present invention is the medical instrument according to any one of the first to fifth aspects of the present invention, wherein the base portion has a flange portion at a distal end portion.

[0013] A seventh invention is any one of the first to sixth inventions, further comprising an exterior part that seals at least the RFID tag and the boost antenna, wherein the distal end of the exterior part is formed in an approximately circular shape, the outer diameter of the boost antenna is 4 mm or less, and the ratio of the outer diameter of the distal end of the boost antenna to the outer diameter of the distal end of the exterior part is 0.6 or less. Effect of the Invention

[0014] In the present invention, the tag installation surface of the base extending inside the spiral boost antenna is located near the distal end of the boost antenna outside the range between both ends of the boost antenna, or inside the distal end of the boost antenna within the range between both ends. Therefore, when installing an RFID tag after installing the boost antenna, the installation position of the RFID tag is not far from the end of the boost antenna inside the boost antenna, making it easy to install the RFID tag coupled to the boost antenna. In addition, a manufacturing method can be adopted in which a wire is wound around the base to form the boost antenna, and it is also easy to provide the boost antenna after installing the RFID tag. According to the present invention, it is possible to facilitate the manufacture of articles with RFID tags. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1(a) is a side view of an RFID-tagged article according to an embodiment, FIG. 1(b) is a top view of the distal side of the base portion of the RFID-tagged article of FIG. 1(a), FIG. 1(c) is an enlarged side view of the distal side of the base portion of the RFID-tagged article of FIG. 1(a), FIG. 1(d) is an enlarged side view of the distal side of the base portion of an RFID-tagged article in which the position of the tag mounting surface is different from that of FIG. 1(c), and FIG. 1(e) is an enlarged side view of the distal side of the base portion of an RFID-tagged article in which the position of the tag mounting surface is different from that of FIG. 1(c) and FIG. 1(d). [Diagram 2] FIG. 2(a) is a side view during an antenna forming step, FIG. 2(b) is a side view after a base fixing step, and FIG. 2(c) is a side view during a cap forming step. [Diagram 3] FIG. 3 is a side view of an RFID tagged item according to a first modified example of the embodiment. [Figure 4] FIG. 4(a) is a front view of the end face of a first columnar section of an RFID-tagged article according to a second modified example of the embodiment, FIG. 4(b) is a front view of the end face of another first columnar section, and FIG. 4(c) is a front view of the end face of yet another first columnar section. [Diagram 5] FIG. 5 is a side view of an RFID tagged item according to a third modified example of the embodiment. [Figure 6] Figure 6(a) is a side view of an RFID-tagged article according to a fourth modified example of the embodiment, with the boost antenna and cap portion omitted, and Figure 6(b) is a cross-sectional view of the base portion, booster antenna and RFID tag of the RFID-tagged article of Figure 6(a). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. Note that the following embodiments and modifications are merely examples of the present invention and are not intended to limit the scope of the present invention, its applications, or its uses.

[0017] [Configuration of RFID tagged items] This embodiment is an RFID tagged article 10 (hereinafter, sometimes referred to as "this article") in which an RFID tag (IC tag) 20 is provided integrally with a bolt 11. As shown in Fig. 1(a), this article 10 includes a metal bolt 11 having a shaft portion 11a and a head portion 11b, and an attachment head portion 12 attached to the base side of the shaft portion 11a of the bolt 11. Note that Fig. 1(a) illustrates the RFID tagged article 10 with the inside of a cap portion 22, which will be described later, being seen through.

[0018] The bolt 11 corresponds to a shaft-equipped part having at least a shaft portion 11a. The shaft-equipped part 11 is a part (e.g., a bolt, a screw, a screw) having a head portion 11b in addition to a shaft portion (threaded portion) 11a having a male thread formed on the outer peripheral surface, a part (e.g., a pin) having a head portion 11b in addition to a shaft portion 11a having a smooth outer peripheral surface, or a part (e.g., a threaded rod) consisting of only a shaft portion (threaded portion, etc.) 11a. The article 10 is used for fixing or holding a member by inserting or screwing the shaft portion 11a of the shaft-equipped part 11. In the bolt 11, the head portion 11b joined to the upper side of the shaft portion 11a protrudes in the width direction of the shaft portion 11a. The width (outer diameter) of the head portion 11b is larger than the outer diameter of the shaft portion 11a. At least a part of the outer peripheral surface of the head portion 11b is chamfered.

[0019] The mounting head 12 is attached to the head 11b of the bolt 11. As shown in Fig. 1(a), the mounting head 12 includes an RFID tag 20 that transmits and receives radio waves, a spiral boost antenna 21 that boosts the radio waves transmitted to and received by the RFID tag 20, a resin base portion 15 that is a member extending inside the boost antenna 21 (inside the spiral) and has a tag installation surface (tip surface) 16 on which the RFID tag 20 is installed, and a resin cap portion 22 that seals at least the RFID tag 20 and the boost antenna 21. The cap portion 22 corresponds to an exterior portion.

[0020] The RFID tag 20 is an RFID inlay. As shown in FIG. 1(b), the RFID tag 20 includes an IC chip 20b, a resonant circuit 20c to which the IC chip 20b is connected, and a small substrate 20a on which the IC chip 20b and the resonant circuit 20c are mounted. The substrate 20a is formed in a substantially rectangular flat plate shape. In the RFID tag 20, an electric circuit formed including the capacitance C of the IC chip 20b and the inductance L of the resonant circuit 20c constitutes an LC resonant circuit. This electric circuit is designed so that the resonant frequency of the LC resonant circuit is the operating frequency of the IC chip 20b or a value close to the operating frequency.

[0021] The IC chip 20b is disposed at the center of the front surface of the substrate 20a. The resonant circuit 20c is configured by a wiring pattern (printed wiring) wound in a spiral shape multiple times, and functions as a coil antenna. The resonant circuit 20c is mounted in an area on the front surface of the substrate 20a that is outside the IC chip 20b. The outermost periphery of the resonant circuit 20c extends along and near each side of the substrate 20a, and is magnetically coupled with the boost antenna 21.

[0022] Even when an RFID inlay is not used for the RFID tag 20 (for example, when a label-type, card-type, round-type, stick-type, or other RFID tag is used), the IC chip and LC resonant circuit can be used to magnetically couple with the boost antenna 21. As for the power supply method for the RFID tag 20, the present embodiment uses a passive method in which the RFID tag 20 does not have a built-in battery, but an active method or semi-passive method may also be used.

[0023] The boost antenna 21 is an antenna for the RFID tag 20 that is magnetically coupled to the resonant circuit 20c of the RFID tag 20. The boost antenna 21 is a wire 21a wound in a spiral shape. The wire 21a is a linear conductor (such as a metal wire) covered with an insulating material (such as a resin). In the boost antenna 21, the conductors of adjacent wires 21a are insulated from each other. The boost antenna 21 is wound around the outer circumferential surface of the base portion 15.

[0024] The boost antenna 21 extends from the proximal side of the bolt 11 at the mounting head 12 to the distal side of the bolt 11 at the mounting head 12. The axial direction of the boost antenna 21 approximately coincides with the axial direction A of the shank 11a of the bolt 11. The boost antenna 21 is disposed coaxially with the shank 11a of the bolt 11. Hereinafter, for configurations other than the boost antenna 21, the upper side in FIG. 1(a) will be referred to as the "distal side" and the lower side in FIG. 1(a) will be referred to as the "proximal side" in the axial direction A of the shank 11a.

[0025] The front side surface of the RFID tag 20 (the surface on which the IC chip 20b and the resonant circuit 20c are mounted) is provided approximately parallel to a plane perpendicular to the axial direction of the boost antenna 21. When the RFID-tagged article 10 is viewed in the axial direction A, the planar dimensions of the RFID tag 20 are set so that the entire RFID tag 20 fits inside the distal end of the boost antenna 21, as shown in FIG.

[0026] As shown in FIG. 1(a), the base 15 has a first columnar section 17 disposed on the proximal side, and a second columnar section 18 integrated with the distal end surface of the first columnar section 17. In the base 15, a boost antenna 21 is wound around the second columnar section 18. The tip surface (top surface) of the second columnar section 18 serves as the tag mounting surface 16. The tip surface of the second columnar section 18 may be formed with a recess 58 (see FIG. 5) into which the RFID tag 20 is fitted. In this case, the bottom surface of the recess 58 serves as the tag mounting surface 16.

[0027] The first columnar portion 17 protrudes in the axial direction A from the upper surface of the head 11b of the bolt 11. The second columnar portion 18 protrudes in the axial direction A from the upper surface of the first columnar portion 17. The first columnar portion 17 and the second columnar portion 18 are integrated. Both the first columnar portion 17 and the second columnar portion 18 are formed in a straight cylindrical shape. Both the first columnar portion 17 and the second columnar portion 18 are provided coaxially with the shaft portion 11a of the bolt 11.

[0028] Comparing the first columnar portion 17 and the second columnar portion 18, the length in the axial direction A of the second columnar portion 18 is longer, and the outer diameter of the first columnar portion 17 is larger. The outer diameter of the first columnar portion 17 is also smaller than the width of the head portion 11b of the bolt 11. A step surface 19 is formed at the boundary position between the first columnar portion 17 and the second columnar portion 18 in the axial direction A. The lower end of the boost antenna 21 abuts against the step surface 19.

[0029] 1(c), the tag installation surface 16 is located near the distal end of the boost antenna 21 outside the range X between both ends of the boost antenna 21. This vicinity means, for example, that the distance L1 from the distal end of the boost antenna 21 in the axial direction A is within three times the thickness D of the wire 21a of the boost antenna 21. In this embodiment, the entire RFID tag 20 is located outside the range X.

[0030] As shown in Fig. 1(d) and Fig. 1(e), the tag installation surface 16 may be located inside the distal end of the boost antenna 21 (inside the spiral) within the range X between both ends of the boost antenna 21. For example, the range of this end is a range in which the distance L2 (see Fig. 1(d) and Fig. 1(e)) from the distal end of the boost antenna 21 in the axial direction A is 1.5 times the thickness D of the wire 21a of the boost antenna 21. In this case, as shown in Fig. 1(d), a part of the RFID tag 20 may be outside the range X, or as shown in Fig. 1(e), the entire RFID tag 20 may be within the range X.

[0031] The cap portion 22 is formed in a generally cylindrical shape with a closed upper end. The cap portion 22 is made of resin. The inner surface of the cap portion 22 is in close contact with the boost antenna 21, etc. The outer circumferential surface of the cap portion 22 is knurled.

[0032] [Method of manufacturing RFID tagged items] A method for producing the article 10 will now be described with reference to FIG.

[0033] The manufacturing method of the present article 10 includes, in this order, a tag installation step of installing and fixing an RFID tag 20 on the tip surface 16 of the base portion 15, an antenna forming step of winding a wire (e.g., an enamel wire) 21a around the base portion 15 to form a boost antenna 21, a base fixing step of fixing the base portion 15 to the head portion 11b of the bolt 11, and a cap forming step of forming a cap portion 22. Note that the tag installation step may be performed after the antenna forming step or the base fixing step.

[0034] FIG. 2(a) is a side view during the antenna forming process. In the antenna forming process, the rotating shaft 32 to which the driving force from the motor 31 is applied is fixed to the first columnar section 17. In addition, the end of the wire 21a is fixed to the end of the second columnar section 18. When the rotating shaft 32 is rotated by the motor 31 in this state, the base section 15 rotates around its axis. As a result, the wire 21a is wound around the outer circumferential surface of the second columnar section 18. When the wire 21a is wound from one end side to the other end side of the second columnar section 18, the boost antenna 21 is completed. The inner diameter of the boost antenna 21 is approximately equal to the outer diameter of the second columnar section 18. Note that, by winding the wire 21a around the outer circumferential surface of the second columnar section 18 while applying tension to the wire 21a, the wire 21a can be wound relatively tightly, which suppresses deformation of the boost antenna 21, which will be described later.

[0035] 2(b) is a side view after the pedestal fixing step. In the pedestal fixing step, when pedestal portion 15 is formed on the upper side of head portion 11b of bolt 11 by insert molding, for example, pedestal portion 15 is fixed to head portion 11b of bolt 11. Note that pedestal portion 15 may be formed and then fixed to head portion 11b by adhesive or the like without performing insert molding.

[0036] 2(c) is a side view during the cap forming process. During the cap forming process, a cap-shaped mold 34 with a resin injection port 33 is placed over the base 15 around which the boost antenna 21 is wound and on which the RFID tag 20 is mounted. Molten resin (molding resin) is then supplied into the mold 34 from the resin injection port 33. The resin fills the gap 35 in the mold 34. The mold 34 is removed after the resin has hardened. When the cap forming process is completed, the article 10 is completed.

[0037] [Effects of this embodiment] In this embodiment, the tag installation surface 16 of the base portion 15 extending inside the spiral boost antenna 21 is located near the distal end of the boost antenna 21 outside the range X between both ends of the boost antenna 21, or inside the distal end of the boost antenna 21 within the range X between both ends. Therefore, even when the RFID tag 20 is installed after the boost antenna 21 is installed, the installation position of the RFID tag 20 is not away from the end of the boost antenna 21 inside the boost antenna 21, and the installation of the RFID tag 20 that is magnetically coupled to the boost antenna is easy. In addition, a manufacturing method of forming the boost antenna 21 by winding the wire 21a around the base portion 15 can be adopted, and the boost antenna 21 can also be easily provided after the RFID tag 20 is installed. According to this embodiment, the manufacture of the RFID tagged item 10 can be facilitated.

[0038] Incidentally, in the RFID tag attachment member described in Patent Document 1, when the diameter of the spiral boost antenna is reduced, the manufacturing of the RFID tagged article 10 becomes increasingly difficult, and therefore it is difficult to reduce the diameter of the boost antenna. In contrast, in this embodiment, in FIG. 1(c), the tag installation surface 16 is outside the above-mentioned range X, so even if the boost antenna 21 is reduced in diameter, the manufacturing of the RFID tagged article 10 does not become difficult, and the boost antenna 21 can be reduced in diameter. Also, in FIG. 1(d) and FIG. 1(e), although the tag installation surface 16 is within the above-mentioned range X, it is located at the distal end of the boost antenna 21, so even if the boost antenna 21 is reduced in diameter, the manufacturing of the RFID tagged article 10 does not become so difficult, and the boost antenna 21 can be reduced in diameter. According to this embodiment, the design freedom of the boost antenna 21 is increased.

[0039] In this embodiment, the spiral boost antenna 21 is formed by winding wire 21a around the outer circumferential surface of second columnar section 18 of base section 15. Here, in a manufacturing method in which boost antenna 21 formed in advance in a spiral shape is attached to second columnar section 18, if the diameter of boost antenna 21 is reduced, it becomes difficult to attach boost antenna 21 to second columnar section 18. In contrast, in this embodiment, it is easy to form a boost antenna 21 with a small diameter. Also, the number of turns and pitch of boost antenna 21 can be easily changed.

[0040] In addition, when the planar shape of the RFID tag 20 is a square, the inner diameter of the boost antenna 21 can be set to be 1 or more and 3 or less times the diagonal length of the RFID tag 20. For example, assuming a square RFID tag 20 with one side measuring 1.2 mm, the inner diameter of the boost antenna 21 is 1.7 mm or more and 5 mm or less. The outer diameter and inner diameter of the boost antenna 21 are uniform in the length direction. The outer diameter of the wire 21a of the boost antenna 21 can be set to a value in the range of 0.3 mm or more and 0.6 mm or less.

[0041] Here, when molten resin is supplied from resin injection port 33 at the top of mold 34 during the cap formation process, there is a risk that boost antenna 21 will shrink or deform due to the pressure of the resin. If this deformation occurs, boost antenna 21 will deviate from its designed shape after the resin has hardened. This deviation causes variation in the shape of boost antenna 21 between products. This problem is particularly likely to occur when the pitch of boost antenna 21 is large.

[0042] In response to this problem, by reducing the diameter of boost antenna 21, gap 35 between the inner peripheral surface of molding die 34 and the outer peripheral surface of boost antenna 21 becomes wider, and resin supplied from resin injection port 33 is more easily guided into gap 35. As a result, the resin pressure acting in the axial direction on boost antenna 21 is reduced. The shape of boost antenna 21 becomes less susceptible to the effects of resin flow. Therefore, by reducing the diameter of boost antenna 21, it is possible to improve the quality of article 10 and improve communication stability.

[0043] In this embodiment, at the height h of the distal end of boost antenna 21, the width of each of the gaps 35 on the left and right sides of base portion 15 is secured to be 0.4 mm or more in the side view shown in FIG. 2(c). In this case, at the height of the distal end of boost antenna 21, the value obtained by subtracting the outer diameter D1 of boost antenna 21 from the outer diameter D2 of cap portion 22 (see FIG. 1(a)) is 0.8 mm or more. For example, when the outer diameter D2 is 6.6 mm, the outer diameter D1 is 5.8 mm or less. The value of outer diameter D2 - outer diameter D1 is secured to be 0.8 mm or more even when boost antenna 21 has a small diameter (for example, when D1≦4 mm). When the outer peripheral surface of cap portion 22 is knurled, outer diameter D2 is measured at the apex of the knurl.

[0044] Furthermore, in this embodiment, when a defect in the RFID tag 20 is discovered after or during the manufacture of the RFID tagged article 10, the RFID tag 20 can be replaced without removing the boost antenna 21. This also makes it possible to improve the quality of the article 10.

[0045] 1(c) to 1(e) are adopted as the tag installation surface 16, there is a risk that the degree of coupling of the boost antenna 21 to the resonant circuit 20c of the RFID tag 20 may decrease (the communication distance may decrease) compared to when the tag installation surface 16 is positioned in the center of the range X. In this embodiment, the tag installation surface 16 is moved away from the center of the range X while taking this disadvantage into consideration. However, by reducing the diameter of the boost antenna 21, it is possible to bring the boost antenna 21 closer to the resonant circuit 20c of the RFID tag 20. By reducing the diameter of the boost antenna 21 and bringing it closer to the resonant circuit 20c of the RFID tag 20, it is possible to stabilize the communication between the RFID tag 20 and the boost antenna 21 while suppressing the above-mentioned decrease in the degree of coupling.

[0046] [First Modification of the Embodiment] In this modification, as shown in Fig. 3, an enclosure 40 is provided to surround the outer circumferential surface of the boost antenna 21. The enclosure 40 is integrated with the base 15. The enclosure 40 is formed, for example, in a cylindrical shape. Note that Fig. 3 illustrates a cross-sectional configuration of the inside of the cap 22 of the RFID tagged item 10.

[0047] The surrounding portion 40 protrudes in the axial direction of the first columnar portion 17 from an edge portion on the upper surface of the first columnar portion 17. A cylindrical gap 41 for accommodating the boost antenna 21 is formed between the inner peripheral surface of the surrounding portion 40 and the outer peripheral surface of the first columnar portion 17. In this case, the boost antenna 21 is disposed in the gap 41 after being formed in a spiral shape in advance.

[0048] In this modification, by providing the enclosing portion 40, it becomes easy to position the boost antenna 21. Therefore, even if the diameter of the boost antenna 21 is reduced, the boost antenna 21 can be installed relatively easily. Furthermore, when resin is supplied from the resin injection port 33 during the cap forming process, the resin does not easily flow into the narrow gap 41, and a large amount of resin is guided to the outside of the enclosing portion 40 (gap 35). Therefore, deformation of the boost antenna 21 during the cap forming process is suppressed, and the quality of the present article 10 can be improved.

[0049] [Second Modification of the Embodiment] In this modification, as shown in Fig. 4(a) and Fig. 4(b), the first columnar section 17 has outer peripheral surface corners 45. A part or the whole of the outer peripheral surface of the first columnar section 17 is chamfered. This makes it easier to hold the first columnar section 17 with a jig provided at the tip of the rotating shaft 32 relative to the outer peripheral shape of the first columnar section 17.

[0050] 4(c), the first columnar section 17 may be configured to have a square hole 50 having a corner 46 formed on its inner circumferential surface. In this case, a fitting structure can be formed by matching the shape of the tip of the rotating shaft 32 to the inner circumferential shape of the square hole 50 of the first columnar section 17.

[0051] [Third Modification of the Embodiment] In this modification, as shown in FIG. 5, the base portion 15 has a flange portion 55 at its distal end. The flange portion 55 is formed in a substantially circular plate shape. The outer diameter of the flange portion 55 is larger than the outer diameter of the second columnar portion 18, and the flange portion 55 protrudes radially outward from the outer circumferential surface of the second columnar portion 18. The flange portion 55 may be integrally formed with the first columnar portion 17 and the second columnar portion 18, or may be fixed to the second columnar portion 18 by adhesive or the like after the flange portion 55 is formed. FIG. 5 shows the inside of the cap portion 22 of the RFID tagged article 10 in a see-through state. However, the flange portion 55 is shown in a cross-sectional configuration.

[0052] In this modification, the tag installation surface 16 is provided on the flange portion 55. Specifically, a recess 58 into which the RFID tag 20 is fitted is formed in the center (the center when viewed from above) of the distal end surface of the flange portion 55, and the bottom surface of the recess 58 serves as the tag installation surface 16. Note that the recess 58 may be made deeper so that the bottom surface of the recess 58 is located on the second columnar portion 18. Also, the distal end surface of the flange portion 55 may serve as the tag installation surface 16 without forming the recess 58.

[0053] In this modified example, when wire 21a is wound around second columnar portion 18 of base portion 15 to form a spiral boost antenna 21, the winding range is determined by flange portion 55, so that the length of boost antenna 21 is constant.

[0054] In this modification, the flange portion 55 is formed to cover the entire boost antenna 21 in top view. This suppresses deformation of the boost antenna 21 due to the pressure of the resin during the cap formation process. The flange portion 55 may cover a portion of the wire 21a of the boost antenna 21 (for example, the center side of the wire 21a) in top view.

[0055] [Fourth Modification of the Embodiment] In this modification, as shown in Fig. 6(a), a spiral groove 56 is formed on the outer circumferential surface of the second columnar section 18 of the base section 15. In the antenna formation process, the wire 21a is wound on the outer circumferential surface of the second columnar section 18 so that the wire 21a fits into the spiral groove 56, thereby forming the spiral boost antenna 21 (see Fig. 6(b)).

[0056] According to this modification, boost antenna 21 is wound around columnar portion 18 while being fitted into helical groove 56. Therefore, even if boost antenna 21 is subjected to the pressure of the resin during the cap formation process, the pitch of boost antenna 21 is fixed and deformation of boost antenna 21 is suppressed, so that the quality of article 10 can be improved.

[0057] [Other variations] In the above embodiment, boost antenna 21 is attached to pedestal portion 15 by winding wire 21a around pedestal portion 15 to form boost antenna 21, but boost antenna 21 formed in advance in a spiral shape may also be attached to pedestal portion 15. In this case, columnar portions 17, 18 of pedestal portion 15 may be in the shape of a square pillar.

[0058] In the above embodiment, the wires 21a adjacent to each other in the axial direction are in contact with each other in the boost antenna 21, but the pitch may be increased to provide a gap between the adjacent wires 21a. Also, the outer diameter and inner diameter of the boost antenna 21 may be changed in the axial direction so as to widen or narrow toward the proximal side. [Industrial Applicability]

[0059] The present invention is applicable to RFID tagged items and the like. [Explanation of symbols]

[0060] 10 RFID tagged items 11 Bolt (shaft attachment part) 11a Shaft 11b Head 12 Head attachment 15 Pedestal 16 Tag installation surface 17 1st columnar part 18 Second columnar part 20 RFID Tags 21 Boost Antenna 22 Cap part (exterior part)

Claims

1. A shaft-equipped part having at least a shaft portion; A mounting head is attached to a base side of the shaft portion of the shaft-equipped part, The mounting head includes: An RFID tag; An antenna for the RFID tag, the antenna being a spiral boost antenna extending from a proximal side of the shaft-equipped part of the mounting head to a distal side of the shaft-equipped part of the mounting head; a base portion that is a member extending inside the boost antenna and has a tag mounting surface on which the RFID tag is mounted; An RFID tagged article, wherein the tag mounting surface is located near the distal end of the boost antenna outside the range between both ends of the boost antenna, or inside the distal end of the boost antenna within the range between the two ends.

2. The RFID tagged article according to claim 1 , further comprising an enclosure portion that is integrated with the base portion and surrounds the outer periphery of the boost antenna.

3. The RFID tagged item of claim 1 , wherein the boost antenna is wrapped around the base portion.

4. The base portion has a columnar portion having a spiral groove formed on an outer circumferential surface, The RFID tagged article according to claim 1 , wherein the boost antenna is wound around the column portion while being fitted into the spiral groove.

5. the base portion has a first pillar-shaped portion disposed on the proximal side, and a second pillar-shaped portion integrated with an end surface on the distal side of the first pillar-shaped portion and around which the boost antenna is wound, The RFID tagged article according to claim 1 , wherein the first columnar portion has a corner on its outer circumferential surface, or has a hole with a corner on its inner circumferential surface.

6. The RFID tagged article according to claim 1 , wherein the base portion has a flange portion at the distal end.

7. Further comprising an exterior part that seals at least the RFID tag and the boost antenna, The outer circumferential surface of the exterior portion is formed in a substantially cylindrical shape.

6. An RFID tagged article according to claim 1, wherein the difference between the outer diameter of the exterior portion and the outer diameter of the boost antenna at the height of the distal end of the boost antenna is 0.8 mm or more.

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