RFID tag-attached article

Abstract

In order to realize an RFID tag-attached article capable of suppressing variation in communication distance in mass production, an RFID tag-attached article 10 comprises: a shaft-equipped component 11 having at least a shaft part 11a; and a mounting head part 12 mounted on the root side of the shaft part 11a of the shaft-equipped component 11. The mounting head part 12 includes an RFID tag 20, a spiral boost antenna 21 which is an antenna for the RFID tag and extends from the proximal side to the distal side of the mounting head part 12 with respect to the shaft-equipped component 11, and a pedestal part 15 which is a member extending inside the boost antenna 21 and has a tag installation surface 16 on which the RFID tag 20 is installed. The tag installation surface 16 is inclined with respect to an orthogonal surface 25 orthogonal to an axis 21a of the boost antenna 21, and the pedestal part 15 is provided with a position determination part 30 for determining the installation position of the RFID tag 20 by restricting the oblique downward movement of the RFID tag 20 on the lower side in the inclination direction of the tag installation surface 16.

Description

RFID tagged items

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

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

[0003] Patent Document 1 describes a wearable member with an RFID tag. This wearable member with an RFID tag includes a shaft-shaped portion having an insert portion and a base portion, an RFID tag that transmits and receives radio waves, a boost antenna that boosts the radio waves transmitted to and received from the RFID tag, and a resin head portion in which at least the surface side of the base portion is molded to enclose the RFID tag and the boost antenna. The boost antenna is a coil spring-shaped conductor with the RFID tag located inside.

[0004] Japanese Patent Application Laid-Open No. 2022-044984

[0005] In an RFID-tagged article such as the RFID-tagged attachment member described in Patent Document 1, the stronger the magnetic field coupling between the resonant circuit (antenna) provided in the RFID tag and the spiral boost antenna, the longer the communication distance of the RFID tag. For example, if the RFID tag is square, aligning the center of the RFID tag with the axis of the boost antenna increases the coupling of the resonant circuit with the boost antenna, thereby lengthening the communication distance of the RFID tag.

[0006] However, in the manufacture of RFID-tagged articles, if an RFID tag is picked up by a mounting device and placed in close contact at a predetermined position on the tag installation surface where the coupling strength of the resonant circuit with the boost antenna is high, the RFID tag may be pressed and damaged when it is placed in close contact, so it is necessary to drop the RFID tag from slightly above the tag installation surface. However, with this installation method, there is a risk that the RFID tag may become misaligned when it is dropped, making it difficult to install the RFID tag in the predetermined position with high precision.

[0007] For example, in the RFID tag mounting member described in Patent Document 1, a recess (a hollow-shaped recessed portion) for mounting an RFID tag is formed on the end face of the protruding portion of the base. While FIG. 2 of Patent Document 1 depicts the RFID tag fitting perfectly into the recess, in reality, the bottom of the recess must be larger than the RFID tag in order for the RFID tag to be attached to the bottom of the recess by the dropping method. However, if the bottom of the recess is made larger, there is a risk that the RFID tag will shift position when dropped, making it difficult to accurately install the RFID tag in a predetermined position. Therefore, when mass-producing RFID tagged products, variations in the installation position of the RFID tag are likely to occur. This also leads to variations in the communication distance (communication characteristics) of the RFID tag.

[0008] The present invention has been made in view of the above circumstances, and aims to realize an RFID tagged article that can suppress variations in communication distance during mass production.

[0009] In order to solve the above-mentioned problems, the first invention is an RFID-tagged article comprising an axially-equipped part having at least a shaft portion, and a mounting head attached to the base side of the shaft portion of the axially-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 mounting head relative to the axially-equipped part to the distal side of the mounting head relative to the axially-equipped part, 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 inclined with respect to an orthogonal plane perpendicular to the axis of the boost antenna, and the base portion being provided with a positioning portion below the inclination of the tag mounting surface which restricts diagonally downward movement of the RFID tag and determines the mounting position of the RFID tag.

[0010] In a second aspect of the present invention, in the first aspect, the inclination angle of the tag installation surface with respect to the perpendicular plane is 20° or more and 45° or less.

[0011] In a third aspect based on the first aspect, the position determining unit is in contact with the RFID tag from below in the oblique direction.

[0012] The fourth invention is the third invention, in which a recess having a bottom surface constituting the tag mounting surface is formed on the distal end surface of the base portion relative to the shaft-equipped part, and the lower wall surface of the recess in the inclined direction of the tag mounting surface functions as a positioning portion.

[0013] The fifth invention is the first invention, wherein the base portion is provided with a tag guidance portion for guiding the RFID tag to a predetermined position in a direction perpendicular to the tilt direction when viewed in the axial direction of the boost antenna.

[0014] In a sixth aspect of the present invention, in the fourth aspect, the lower wall surface when viewed in the axial direction of the boost antenna has a pair of linear walls that widen upward in the tilt direction.

[0015] The seventh invention is the first invention, in which a recess having a bottom surface that forms the tag mounting surface is formed on the distal end face of the base portion relative to the axially equipped part, and when viewed in the axial direction of the boost antenna, wall protrusions that protrude toward the inside of the recess are formed at multiple locations spaced apart from each other on the wall surface of the recess.

[0016] In an eighth aspect of the present invention, in the seventh aspect, the wall projections formed at a plurality of locations include a pair of wall projections that face each other when viewed in the axial direction of the boost antenna.

[0017] A ninth invention is the eighth invention, wherein the pair of wall protrusions are first wall protrusions that face each other in a first direction when viewed in the axial direction of the boost antenna, and the wall protrusions formed at multiple locations further include, in addition to the first wall protrusions, a pair of second wall protrusions that face each other in a second direction perpendicular to the first direction when viewed in the axial direction of the boost antenna.

[0018] In a tenth aspect of the present invention, in the seventh aspect, the tip of the wall projection when viewed in the axial direction of the boost antenna is a corner.

[0019] In an eleventh aspect of the present invention, in the fourth aspect, at least the surface of the lower wall that comes into contact with the RFID tag is formed substantially perpendicular to the tag installation surface.

[0020] In a twelfth aspect of the present invention, in the fourth aspect, the lower wall surface is configured as a straight wall that is perpendicular to the inclination direction of the tag installation surface when viewed in the axial direction of the boost antenna.

[0021] The thirteenth invention is the twelfth invention, wherein the outer peripheral shape of the distal end face is approximately circular when viewed in the axial direction of the boost antenna, and the upper wall surface of the recess in the inclined direction of the tag mounting surface extends in a curved shape along the outer periphery of the end face when viewed in the axial direction of the boost antenna.

[0022] In a fourteenth aspect of the present invention, in the thirteenth aspect, the upper wall surface is formed in a tapered shape that widens toward the distal end surface.

[0023] The fifteenth invention is the first invention, wherein the shaft-equipped part further has a head joined to the base of the shaft, and the base part is directly installed on the head, thereby attaching the mounting head to the shaft-equipped part, and a recess is formed on one of the surface of the head opposite the shaft part and the end face of the base part proximal to the shaft-equipped part, and a protrusion that fits into the recess is formed on the other.

[0024] In the present invention, the tag installation surface on which the RFID tag is installed is inclined with respect to a plane perpendicular to the axis of the boost antenna. The base is provided with a positioning unit below the inclination of the tag installation surface, which restricts the RFID tag from moving diagonally downward and determines the installation position of the RFID tag. With this configuration, during the manufacturing process of RFID-tagged products, when an RFID tag is dropped from above the tag installation surface, the RFID tag moves diagonally downward due to gravity on the inclined tag installation surface, but the diagonal downward movement of the RFID tag is restricted by the positioning unit. The restricted position becomes the installation position of the RFID tag. Therefore, by providing a positioning unit that restricts the RFID tag at a desired installation position, it is possible to install the RFID tag with high precision. According to the present invention, RFID-tagged products that can suppress variation in communication distance during mass production can be realized.

[0025] FIG. 1 is a side view of an RFID-tagged item according to an embodiment. FIG. 2A is a perspective view of a base of the RFID-tagged item according to an embodiment. FIG. 2B is a front view of the distal end surface of the base in FIG. 2A. FIG. 2C is a cross-sectional view taken along the line A-A in FIG. 2B. FIG. 3A is a diagram illustrating a state in which an RFID tag is falling during a tag installation process included in a method for manufacturing an RFID-tagged item according to an embodiment. FIG. 3B is a diagram illustrating a state in which an RFID tag moves while sliding down the tag installation surface after falling onto the tag installation surface during the tag installation process. FIG. 3C is a diagram illustrating a state in which the RFID tag has been positioned by a positioning unit during the tag installation process. FIG. 4A is a perspective view of a base of an RFID-tagged item according to a first modified example of the embodiment. FIG. 4B is a front view of the distal end surface of the base in FIG. 4A. FIG. 4C is a cross-sectional view taken along the line B-B in FIG. 4B. Fig. 5A is a perspective view of a base of an RFID-tagged article according to a second modified example of the embodiment, Fig. 5B is a front view of a distal end surface of the base of Fig. 5A, and Fig. 5C is a cross-sectional view taken along the line CC of Fig. 5B. Fig. 6A is a perspective view of a base of an RFID-tagged article according to a third modified example of the embodiment, Fig. 6B is a front view of a distal end surface of the base of Fig. 6A in a state where an RFID tag is not installed on the tag installation surface of the base of Fig. 6A, and Fig. 6C is a front view of a distal end surface of the base of Fig. 6A in a state where an RFID tag is installed on the tag installation surface of the base of Fig. 6A. Fig. 7A is a perspective view of a base of an RFID-tagged article according to a fourth modified example of the embodiment, and Fig. 7B is a front view of a distal end surface of the base of Fig. 7A in a state where an RFID tag is not installed on the tag installation surface of the base of Fig. 7A. Fig. 8A is a front view of the distal end surface of the base in a state where an RFID tag is installed on the tag installation surface of the base in Fig. 7A, Fig. 8B is a diagram showing a state where the RFID tag is installed in a slightly rotated state, and Fig. 8C is a cross-sectional view when a chamfer is provided at the upper end of the wall projection. Fig. 9 is a perspective view of the base in a fourth modified example of the embodiment when the tag installation surface 16 is not inclined. Fig. 11 is a perspective view of the shaft-equipped part and the base in an RFID-tagged article according to a fifth modified example of the embodiment, in which the shaft-equipped part and the base are disassembled.

[0026] Hereinafter, 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.

[0027] [Configuration of RFID tagged item] This embodiment is an RFID tagged item 10 (hereinafter, sometimes referred to as "this item") in which an RFID tag (IC tag) 20 is provided integrally with a bolt 11. As shown in Fig. 1 , this item 10 includes a metal bolt 11 having a shank 11a and a head 11b, and an attachment head 12 attached to the base of the shank 11a of the bolt 11. Note that Fig. 1 illustrates the RFID tagged item 10 in a see-through state, showing the inside of a cap portion 22 (described later).

[0028] The bolt 11 corresponds to a shaft-equipped part having at least a shank 11a. The shaft-equipped part 11 is a part (e.g., a bolt, screw, or screw) having a shank (threaded part) 11a with a male thread formed on the outer peripheral surface and a head 11b, a part (e.g., a pin) having a shank 11a with a smooth outer peripheral surface and a head 11b, or a part (e.g., a threaded rod) consisting only of a shank (threaded part, etc.) 11a. The article 10 is used to fasten or hold various members such as plate materials by inserting or screwing the shank 11a of the shaft-equipped part 11. In the bolt 11, the head 11b joined to the upper side of the shank 11a protrudes in the width direction of the shank 11a. The width (outer diameter) of the head 11b is larger than the outer diameter of the shank 11a. At least a portion of the outer peripheral surface of the head 11b is chamfered.

[0029] The mounting head 12 is attached to the head 11b of the bolt 11. 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 from the RFID tag 20, a resin base 15 that is a component disposed inside the boost antenna 21 (inside the spiral) and has a tag mounting surface 16 on which the RFID tag 20 is mounted, and a resin cap 22 that seals at least the RFID tag 20 and the boost antenna 21. In this embodiment, the tag mounting surface 16 is inclined with respect to an orthogonal plane 25 that is orthogonal to the axis 21a of the boost antenna 21 (see FIG. 2C ). The orthogonal plane 25 is a virtual plane that does not actually exist.

[0030] The cap portion 22 corresponds to an exterior portion. 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 and the like. The outer peripheral surface of the cap portion 22 is knurled.

[0031] The RFID tag 20 is an RFID inlay. The RFID tag 20 is provided within a range between both ends of the boost antenna 21 in the height direction. The RFID tag 20 is formed in a substantially rectangular shape (e.g., a square, a rectangle, or a rectangle with the four corners rounded) when viewed from the front. 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 (see FIG. 2B ).

[0032] 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 it.

[0033] The IC chip 20b is disposed in the center of the front surface of the substrate 20a. The resonant circuit 20c is configured with a wiring pattern (printed wiring) surrounding the IC chip 20b and functions as a coil antenna. In this embodiment, the resonant circuit 20c is configured with a rectangular enclosure-shaped pattern. The resonant circuit 20c is mounted in an area outside the IC chip 20b on the front surface of the substrate 20a. The resonant circuit 20c extends along and near each side of the substrate 20a and is magnetically coupled to the boost antenna 21. Note that, although the resonant circuit 20c surrounds the IC chip 20b in a single layer in this embodiment, it may be formed to surround the IC chip 20b in two or more layers.

[0034] Even when an RFID inlay is not used in 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. Furthermore, regarding the power supply method for the RFID tag 20, this embodiment uses a passive method in which the RFID tag 20 does not have a built-in battery, but an active method or a semi-passive method may also be used.

[0035] 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 made of a wire formed into a spiral shape. The wire 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 are insulated from each other. The boost antenna 21 is provided so as to surround the base portion 15.

[0036] The boost antenna 21 extends from the proximal side of the mounting head 12 relative to the bolt 11 to the distal side of the mounting head 12 relative to the bolt 11. The axial direction of the boost antenna 21 substantially 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 of Fig. 1 in the axial direction A of the shank 11a will be referred to as the "distal side" and the lower side of Fig. 1 as the "proximal side."

[0037] The base 15 is a portion fixed onto the shaft-equipped component 11. As shown in Fig. 1 , the base 15 has a first columnar portion 17 disposed on the proximal side and a second columnar portion 18 integrated with the distal end surface of the first columnar portion 17. In the base 15, a boost antenna 21 is wound around the second columnar portion 18. The second columnar portion 18 extends in the axial direction A within the boost antenna 21.

[0038] 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 shank 11a of the bolt 11. In the base portion 15 (second columnar portion 18), the outer peripheral shape of the distal end face (top surface) 19 is approximately circular in a front view. In this embodiment, the distal end face 19 is perpendicular to the axis 21a of the boost antenna 21, and therefore, when viewed from the front, the distal end face 19 is viewed in the same direction as when viewed in the axial direction of the boost antenna 21.

[0039] 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. A step surface is formed at the boundary 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 this step surface. The outer diameter of the first columnar portion 17 is also smaller than the width of the head portion 11b of the bolt 11.

[0040] In this embodiment, as shown in FIGS. 2A to 2C , a recess 29 is formed in the distal end surface 19 of the base 15. A bottom surface 29a of the recess 29 constitutes the tag installation surface 16 on which the RFID tag 20 is installed. The recess 29 is a depression extending proximally, which allows the RFID tag 20 to be positioned closer to the center within the range between both ends of the boost antenna 21. As described above, the tag installation surface 16 is inclined with respect to the orthogonal plane 25 (see FIG. 2C ). The inclination angle θ of the tag installation surface 16 with respect to the orthogonal plane 25 is, for example, 10° or greater. For example, the inclination angle θ can be 15° or greater, preferably 20° or greater. The inclination angle θ can also be 45° or less.

[0041] In this embodiment, in a side view of the article 10 shown in Fig. 1, the half-wound wire on the front side of the page in Fig. 1 in the boost antenna 21 is inclined toward the same side as the tag installation surface 16. Fig. 1 is a side view seen in a direction perpendicular to the inclination direction of the tag installation surface 16, and the inclination direction of the half-wound wire is indicated by a two-dot chain line 26. The tag installation surface 16 is also inclined with respect to this half-wound wire (two-dot chain line 26).

[0042] 2B (hereinafter referred to as "front view of the end face"), the opening of the recess 29 has a substantially D-shape. The wall surface of the recess 29 includes a linear wall 31 that extends linearly and a curved wall 32 that extends curvedly in the front view of the end face.

[0043] The straight wall 31 is the lower wall surface of the recess 29 in the inclination direction of the tag installation surface 16. In a front view of the end surface, the straight wall 31 extends in a direction perpendicular to the inclination direction of the tag installation surface 16 (the left-right direction in FIG. 2B ). As shown in FIG. 2C , the straight wall 31 includes a bottom side wall surface 31a formed substantially perpendicular (e.g., vertical) to the tag installation surface 16 in a cross-sectional view, and an opening side wall surface 31b extending from the upper end of the bottom side wall surface 31a to the edge of the opening of the recess 29. The bottom side wall surface 31a can be formed by chamfering, and in that case, it may be referred to as a "C-surface." The opening side wall surface 31b is formed substantially perpendicular to the distal end surface 19.

[0044] In a front view of the end face, the curved wall 32 extends in an arc shape along the outer periphery 19a of the distal end face 19. The curved wall 32 extends from one end of the straight wall 31, passes above the tag installation surface 16 in the inclination direction, and reaches the other end of the straight wall 31. The curved wall 32 includes an upper wall surface of the recess 29 in the inclination direction of the tag installation surface 16, and a pair of wall surfaces connecting the lower wall surface (straight wall 31) and the upper wall surface. The curved wall 32 is formed approximately perpendicular to the distal end face 19.

[0045] The base 15 is provided with a positioning unit 30 on the lower side of the tag installation surface 16 in the inclined direction, which determines the installation position of the RFID tag 20 by restricting the RFID tag 20 from moving diagonally downward (see FIG. 2C). The RFID tag 20 is placed at a position restricted by the positioning unit 30. The positioning unit 30 is in contact with the RFID tag 20 from below in the inclined direction. Note that the RFID tag 20 is not shown in FIG. 2A.

[0046] In this embodiment, the bottom side wall surface 31a of the linear wall 31 functions as the positioning unit 30. Specifically, the side surface 20s on the lower side (the right side in FIG. 2C ) of the RFID tag 20, which is inclined on the tag installation surface 16, contacts the bottom side wall surface 31a, thereby restricting the RFID tag 20 from moving diagonally downward. Because the lower side surface 20s is formed perpendicular to the bottom surface of the RFID tag 20 and the bottom side wall surface (contact surface for the RFID tag 20) 31a is formed perpendicular to the tag installation surface 16, the lower side surface 20s is in surface contact with the bottom side wall surface 31a over, for example, the entire surface. In a front view of the end surface, one side of the periphery of the RFID tag 20 (the long side of the side surface 20s) is in contact with the bottom side wall surface 31a over the entire length. The angle of the bottom wall surface 31a with respect to the tag installation surface 16 may be greater or less than 90° so that the lower side surface 20s does not come into surface contact with the bottom wall surface 31a, but only one side of the lower side surface 20s comes into contact with the bottom wall surface 31a along its entire length. Furthermore, when viewed from the front end, the RFID tag 20 may be installed in a state rotated from that shown in FIG. 2B . In this case, the lower side surface 20s comes into point contact with the bottom wall surface 31a.

[0047] [Method for manufacturing an article with an RFID tag] The method for manufacturing the article 10 involves performing, in this order, a base fixing process for fixing the base portion 15 to the head 11b of the bolt 11, a tag installation process for installing and fixing the RFID tag 20 on the tag installation surface 16, an antenna installation process for providing a boost antenna 21 on the base portion 15, and a cap formation process for forming the cap portion 22. The tag installation process will be described below with reference to FIG. 3.

[0048] In the tag installation process, first, the RFID tag 20 is picked up by a mounting device (not shown) and dropped from above the tag installation surface 16 (see FIG. 3A ). For example, the RFID tag 20 is dropped from above the center of the tag installation surface 16. The RFID tag 20 then reaches the tag installation surface 16 and moves diagonally downward on the tag installation surface 16 due to gravity (see FIG. 3B ). The RFID tag 20 then collides with the bottom side wall surface 31 a and stops (see FIG. 3C ). The diagonally downward movement of the RFID tag 20 is restricted by the position determination unit 30. The position determination unit 30 functions as a stopper that stops the RFID tag 20. In this embodiment, the position restricted by the position determination unit 30 is the installation position of the RFID tag 20. The RFID tag 20 is guided to a predetermined position by the tag installation surface 16 and the bottom side wall surface 31 a.

[0049] After the RFID tag 20 reaches (drops from) the tag installation surface 16, if the RFID tag 20 does not slide diagonally downward due to friction with the tag installation surface 16, the RFID tag 20 can be guided to a predetermined position by applying a force to the RFID tag 20 in a direction along the tag installation surface 16. Methods for applying a force to the RFID tag 20 include vibrating (slightly vibrating) the base 15, tilting the base 15, or applying wind pressure from above in the tilting direction. In the tag installation process, after the RFID tag 20 is positioned by the bottom side wall surface 31 a, the RFID tag 20 may be fixed to the base 15 with an adhesive.

[0050] Thereafter, the antenna forming step and the cap forming step are performed in sequence to complete the product 10. Note that the order of the three steps of the tag installation step, antenna forming step, and base fixing step is not limited to the above-mentioned order, and any step may be performed first, or any step may be performed second.

[0051] [Effects of the Present Embodiment] In the present embodiment, the tag installation surface 16 is inclined with respect to an orthogonal plane 25 that is orthogonal to the axis 21 a of the boost antenna 21. The base 15 is provided with a position determination unit 30 below the inclination of the tag installation surface 16, which regulates (prevents) the RFID tag 20 from moving diagonally downward and determines the installation position of the RFID tag 20. With this configuration, when the RFID tag 20 is dropped from above the tag installation surface 16 during the manufacturing process of the present article 10, when the RFID tag 20 moves diagonally downward on the inclined tag installation surface 16 due to gravity, the diagonal downward movement of the RFID tag 20 is regulated by the position determination unit 30. The regulated position is the installation position of the RFID tag.

[0052] Therefore, by providing the position determination unit 30 so that the RFID tag 20 is restricted to a predetermined position (planned installation position) where it is desired to install, it is possible to install the RFID tag 20 with high precision. In this embodiment, it is possible to install the RFID tag 20 with high precision, particularly in the inclined direction of the tag installation surface 16 (the left-right direction in FIG. 2B ) when viewed from the front of the end face. According to this embodiment, it is possible to realize RFID-tagged articles 10 that can suppress variations in communication distance during mass production.

[0053] Here, when the RFID tag 20 is inclined with respect to the orthogonal plane 25 as in this embodiment, the degree of coupling of the resonant circuit 20c with the boost antenna 21 is lower than when the RFID tag 20 is provided parallel to the orthogonal plane 25, and the communication distance of the RFID tag 20 is reduced. However, the inventors of the present application have noticed that even if the RFID tag 20 is inclined to a certain extent, the communication distance does not decrease significantly. In mass production of RFID-tagged articles 10, suppressing the variation in communication distance even if the communication distance is slightly reduced results in better mass-produced quality of the RFID-tagged articles 10, than when the maximum value of the communication distance of the RFID tag 20 is large but the variation in communication distance becomes large.

[0054] In terms of communication distance, the inclination angle θ of the tag installation surface is preferably 45° or less. Furthermore, in order to make it easier for the RFID tag 20 to slide down the tag installation surface 16 to the bottom side wall surface 31 a after the RFID tag 20 is dropped during the manufacturing process of the RFID tagged article 10, the inclination angle θ of the tag installation surface is preferably 20° or more.

[0055] However, even if the inclination angle θ of the tag installation surface is less than 20°, it is possible to guide the RFID tag 20 to a predetermined position by applying a force to the RFID tag 20 in a direction along the tag installation surface 16 after dropping the RFID tag 20.

[0056] In this embodiment, the lower side surface 20s of the RFID tag 20, which is inclined on the tag installation surface 16, is in surface contact with the bottom side wall surface 31a, for example, over the entire surface. This makes it easy to design the position of the bottom side wall surface 31a so that the center of the RFID tag 20 coincides with the axis 21a of the boost antenna 21 with high accuracy.

[0057] In this embodiment, the curved wall 32 extends in an arc shape along the outer periphery 19a of the distal end face 19 in a front view of the end face. This makes it easier to ensure the area of ​​the tag installation surface 16, and makes it easier to install the RFID tag 20 in the recess 29 if it falls.

[0058] [First Modification of the Embodiment] In this modification, the curved wall 32 is formed in a tapered shape that widens toward the distal end face 19, as shown in Figures 4A to 4C. In this case, while ensuring the area of ​​the opening of the recess 29, the bottom surface 29a of the recess 29 (i.e., the tag installation surface 16) can be narrowed, and the dimension of the bottom side wall surface 31a in a direction perpendicular to the inclination direction of the tag installation surface 16 can be shortened. Therefore, in an installation method in which an RFID tag 20 picked by a mounting device is dropped, it is possible to maintain the ease of dropping the RFID tag 20 onto the tag installation surface 16, and to install the RFID tag 20 with high precision not only in the inclination direction of the tag installation surface 16 when viewed from the front of the end face, but also in the direction perpendicular to the inclination direction (the up and down direction in Figure 4B).

[0059] [Second Modification of the Embodiment] Unlike the first and second modifications, the wall surfaces of the recess 29 in this modification do not have straight walls 31 but are composed only of curved walls 32. Specifically, as shown in FIGS. 5A and 5B, the tag installation surface 16 is formed in a substantially circular shape when viewed from the front of the end surface. In the curved wall 32, the bottom surface 32a of the lower wall surface in the inclination direction of the tag installation surface 16 functions as the positioning unit 30. As shown in FIG. 5C, the angle between this lower wall surface and the tag installation surface 16 is less than 90°. In this embodiment, two vertices of the upper edge of the side surface 20s of the RFID tag 20 contact the bottom surface 32a of the lower wall surface. Note that, in this modification, the curved wall 32 is formed in a tapered shape that widens toward the distal end surface 19 around the entire circumference. However, the curved wall 32 may also be formed perpendicular to the distal end surface 19.

[0060] [Third Modification of the Embodiment] In this modification, the base 15 is provided with a tag guide unit 35 shown in Fig. 6A. The tag guide unit 35 is a portion for guiding the RFID tag 20 to a predetermined position in a direction perpendicular to the tilt direction of the tag installation surface 16 (hereinafter referred to as the "tilt-perpendicular direction") in a front view of the end face shown in Fig. 6B. The predetermined position is the center position in the tilt-perpendicular direction. In the tilt-perpendicular direction, this center position coincides with the position of the axis of the boost antenna 21.

[0061] The tag guiding section 35 is configured by a lower wall surface 35 of the wall surfaces of the recess 29 in the inclination direction of the tag installation surface 16 (hereinafter simply referred to as the "inclination direction"). The positioning section 30 also serves as the tag guiding section 35. In a front view of the end face, the lower wall surface 35 has a pair of linear walls 35a, 35b that extend from the bottom in the inclination direction toward the upper side in the inclination direction (the left side in FIG. 6B ).

[0062] The pair of linear walls 35 a, 35 b are generally V-shaped when viewed from the front of the end face. Each linear wall 35 a, 35 b extends linearly when viewed from the front of the end face. Each linear wall 35 a, 35 b is inclined so as to widen upward from the tag mounting surface 16 (toward the distal end face 19).

[0063] The pair of straight walls 35a, 35b intersect at the bottom in the inclined direction. When viewed from the front of the end face, the angle θc formed by the pair of straight walls 35a, 35b on the tag installation surface 16 is 90° or more. For example, by making the angle θc slightly larger than 90°, the RFID tag 20 can be more easily moved diagonally downward during the tag installation process. The angle θc is, for example, 110° or less.

[0064] In this modification, the upper wall surface of the recess 29 in the inclined direction is configured as a curved wall 32 that is arc-shaped when viewed from the front of the end face. The curved wall 32 tapers upward from the tag installation surface 16.

[0065] In this modification, when the RFID tag 20 that has fallen onto the tag installation surface 16 moves diagonally downward on the tag installation surface 16 due to gravity, it is guided to a center position in the direction perpendicular to the inclination by a pair of linear walls 35 a, 35 b (see FIG. 6C ). This makes it possible to install the RFID tag 20 with high precision in the direction perpendicular to the inclination. It is also possible to easily align the center of the RFID tag 20 with the position of the axis 21 a of the boost antenna 21 in the direction perpendicular to the inclination.

[0066] 7A and 7B , wall projections 41, 42 that protrude toward the inside of the recess 29 are formed at a plurality of locations spaced apart from each other in a front view of the end face on the wall surface of the recess 29 in this modification. In this modification, the wall projections 41, 42 are formed at four locations.

[0067] The wall surfaces of the recess 29, excluding the four wall protrusions 41, 42, are formed in an arc shape centered on the axis 15a of the base portion 15 when viewed from the front of the end surface, and taper upward from the tag mounting surface 16.

[0068] The four wall projections 41, 42 include a pair of first wall projections 41 facing each other in a first direction in a front view of the end face, and a pair of second wall projections 42 facing each other in a second direction perpendicular to the first direction. In this modification, the first direction coincides with the inclination direction.

[0069] Each wall projection 41, 42 extends in the height direction from the tag mounting surface 16 to the distal end face 19. Each wall projection 41, 42 has a triangular shape when viewed from the front of the end face. The tip of each wall projection 41, 42 when viewed from the front of the end face forms a corner. Each wall projection 41, 42 also has a pair of linear walls 41 a, 42 a extending from the corner when viewed from the front of the end face. The pair of linear walls 41 a, 42 a are inclined so as to widen upward from the tag mounting surface 16. Note that each wall projection 41, 42 may be formed to have another shape, such as an arc shape, when viewed from the front of the end face.

[0070] In this modification, the distance L1 (see FIG. 7A ) between the pair of first wall projections 41 on the tag installation surface 16 is approximately equal to one side of the RFID tag 20 (strictly speaking, slightly longer). Furthermore, the distance L2 (see FIG. 7B ) between the pair of second wall projections 42 on the tag installation surface 16 is approximately equal to one side of the RFID tag 20. Therefore, when the RFID tag 20 is dropped in the above-described tag installation process, each side of the RFID tag 20 is restrained by the four wall projections 41, 42, and the RFID tag 20 is guided to a predetermined position (see FIG. 8A ). The lower first wall projection 41 also functions as the positioning unit 30. Furthermore, the pair of second wall projections 42 also function as the tag guiding unit 35.

[0071] Furthermore, in this modified example, the contact area between the RFID tag 20 and the wall surface of the recess 29 is small, so when the RFID tag 20 is dropped, it is unlikely that the RFID tag 20 will get caught on the wall surface of the recess 29 and rotate, and the RFID tag 20 can be easily installed on the tag installation surface 16.

[0072] Since the RFID tag 20 is only in point contact with the corners of the wall projections 41 and 42 when viewed from the front of the end face, the RFID tag 20 may rotate slightly (see FIG. 8B). However, even in this case, the center of the RFID tag 20 can be made to approximately coincide with the position of the axis 21 a of the boost antenna 21.

[0073] 8C , the upper end portions 43 of the wall projections 41, 42 extending in the height direction may be chamfered (C-chamfered, R-chamfered, etc.) so that the protrusion length gradually decreases. In this case, the entrance of the recess 29 widens, making it easier to drop the RFID tag 20 onto the tag installation surface 16.

[0074] This modified example can also be applied when the tag installation surface 16 is not inclined (i.e., when the tag installation surface 16 is perpendicular to the axis of the boost antenna 21). The base 15 in this case is shown in Figures 9A and 9B. In this case, as in the embodiment, the RFID tagged item 10 includes the shaft-equipped part 11 and the mounting head 12. The mounting head 12 includes the RFID tag 20, the spiral boost antenna 21, and the base 15 in which a recess 29 having a bottom surface that constitutes the tag installation surface 16 is formed. To address the issue of improving the installation accuracy of the RFID tag 20, wall projections 41, 42 that protrude toward the inside of the recess 29 are formed at multiple locations spaced apart from each other on the wall surface of the recess 29 in a front view of the end surface. To improve the installation accuracy of the RFID tag 20 in one direction in a front view of the end surface, the wall projections 41, 42 formed at multiple locations may include a pair of wall projections 41. In addition, in order to improve the installation accuracy of the RFID tag 20 in two directions when viewed from the front of the end face, the wall protrusions 41, 42 formed at multiple locations may include a pair of second wall protrusions 42 in addition to a pair of first wall protrusions 41.

[0075] 10 , in this modification, a recess 45 is formed on one of the surface (upper surface) 8 of the head 11b of the shaft-equipped part 11 opposite to the shaft 11a side and the end surface 9 of the base 15 proximal to the shaft-equipped part 11, and a protrusion 46 that fits into the recess 45 is formed on the other. Note that Fig. 10 shows only the base 15 of the mounting head 12.

[0076] In this modified example, a recess 45 is formed in the center of the upper surface 8 of the head 11b. The recess 45 is formed so as to narrow as it approaches the bottom. The recess 45 is, for example, a conical hole. Furthermore, a protrusion 46 is formed in the center of the proximal end surface 9 of the base 15 (the lower surface of the first columnar portion 17). The protrusion 46 is a circular protrusion in plan view. The protrusion 46 may be formed so as to narrow as it approaches the top, for example.

[0077] Here, if the recess 45 and the protrusion 46 are not provided, the diameter of the first columnar portion 17 of the base portion 15 is smaller than that of the head portion 11b, making it difficult to fix the first columnar portion 17 coaxially to the head portion 11b. According to this modification, when attaching the base portion 15 to the shaft-equipped part 11, the axis of the base portion 15 can be easily aligned with the axis of the shaft-equipped part 11. Alternatively, the protrusion 46 may be formed on the upper surface 8 of the head portion 11b, and the recess 45 may be formed on the lower surface of the first columnar portion 17.

[0078] [Other Modifications] In the above-described embodiment, the recess 29 is formed in the distal end surface 19 of the base 15, but the end surface (top surface) 19 of the base 15 may serve as the tag installation surface 16 without forming the recess 29 in the end surface 19. In this case, a protrusion or the like that functions as the position determining unit 30 is provided on the end surface 19. Also, in the above-described embodiment, the position determining unit 30 is the lower wall surface of the wall surface of the recess 29 in the inclination direction of the tag installation surface 16, but a protrusion may be provided on the tag installation surface 16, and the protrusion may serve as the position determining unit 30.

[0079] In the above-described embodiment, the columnar portions 17 and 18 of the base portion 15 may be formed in a prismatic shape.

[0080] In the above-described embodiment, the RFID tag 20 may be formed in a shape other than a substantially rectangular shape (for example, a circular shape) when viewed from the front.

[0081] In the above-described embodiment, the wire rods 21b (see FIG. 1) adjacent in the axial direction of the boost antenna 21 abut against each other, but the pitch may be increased so that there is a gap between the adjacent wire rods 21b. Also, the outer diameter and inner diameter of the boost antenna 21 may change in the axial direction so that they widen or narrow toward the proximal side.

[0082] The present invention is applicable to items with RFID tags and the like.

[0083] REFERENCE SIGNS LIST 10 RFID tagged item 11 Bolt (shaft-equipped part) 11a Shaft 11b Head 12 Mounting head 15 Base 16 Tag installation surface 20 RFID tag 21 Boost antenna 21a Shaft center 22 Cap (exterior) 25 Orthogonal surface 29 Recess 30 Positioning portion 31 Straight wall 31a Bottom side wall surface 32 Curved wall

Claims

1. An RFID tagged item comprising: a shaft-equipped part having at least a shaft portion; and a mounting head attached to the base side of the shaft portion of the shaft-equipped part, wherein the mounting head comprises: an RFID tag; an antenna for the RFID tag, the antenna being a spiral boost antenna extending from the proximal side of the mounting head relative to the shaft-equipped part to the distal side of the mounting head relative to the shaft-equipped part; 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 inclined with respect to an orthogonal plane perpendicular to the axis of the boost antenna, and the base portion being provided with a positioning portion below the inclination of the tag mounting surface which restricts diagonally downward movement of the RFID tag and determines the mounting position of the RFID tag.

2. The RFID tagged item according to claim 1, wherein the angle of inclination of the tag mounting surface relative to the perpendicular plane is between 20° and 45°.

3. The RFID tagged item according to claim 1, wherein the positioning section contacts the RFID tag from below in the tilt direction.

4. An RFID tagged item as described in claim 3, wherein a recess having a bottom surface constituting the tag mounting surface is formed on the distal end surface of the base portion relative to the shaft-equipped part, and the lower wall surface of the recess in the inclined direction of the tag mounting surface functions as the positioning portion.

5. An RFID tagged item as described in claim 1, wherein the base portion is provided with a tag guidance portion for guiding the RFID tag to a predetermined position in a direction perpendicular to the tilt direction when viewed in the axial direction of the boost antenna.

6. An RFID tagged item according to claim 4, wherein the lower wall surface has a pair of straight walls that widen upward in the tilt direction when viewed in the axial direction of the boost antenna.

7. An RFID tagged item as described in claim 1, wherein a recess having a bottom surface constituting the tag mounting surface is formed on the distal end surface of the base portion relative to the axially equipped part, and when viewed in the axial direction of the boost antenna, wall protrusions protruding toward the inside of the recess are formed at multiple locations spaced apart from each other on the wall surface of the recess.

8. An RFID tagged item according to claim 7, wherein the wall projections formed at a plurality of locations include a pair of wall projections that face each other when viewed in the axial direction of the boost antenna.

9. An RFID tagged item as described in claim 8, wherein the pair of wall protrusions are first wall protrusions that face each other in a first direction when viewed in the axial direction of the boost antenna, and the wall protrusions formed at the multiple locations further include, in addition to the first wall protrusions, a pair of second wall protrusions that face each other in a second direction perpendicular to the first direction when viewed in the axial direction of the boost antenna.

10. An RFID tagged item according to claim 7, wherein the tip of the wall projection when viewed in the axial direction of the boost antenna is a corner.

11. The RFID tagged item according to claim 4, wherein at least the surface of the lower wall that comes into contact with the RFID tag is formed substantially perpendicular to the tag mounting surface.

12. An RFID tagged item as described in claim 4, wherein the lower wall surface is composed of a straight wall that is perpendicular to the inclination direction of the tag installation surface when viewed in the axial direction of the boost antenna.

13. An RFID tagged item as described in claim 12, wherein the outer peripheral shape of the distal end face is approximately circular when viewed in the axial direction of the boost antenna, and the upper wall surface of the recess in the inclined direction of the tag mounting surface extends in a curved shape along the outer periphery of the end face when viewed in the axial direction of the boost antenna.

14. The RFID tagged article according to claim 13, wherein the upper wall surface is tapered to widen toward the distal end surface.

15. An RFID tagged item as described in claim 1, wherein the shaft-equipped part further has a head joined to the base of the shaft, and the base is directly installed on the head, thereby attaching the mounting head to the shaft-equipped part, and a recess is formed on one of the surface of the head opposite the shaft side and the end face of the base proximal to the shaft-equipped part, and a protrusion that fits into the recess is formed on the other.

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