RFID gate system
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- FUJITSU FRONTECH LTD
- Filing Date
- 2023-03-20
- Publication Date
- 2026-05-26
Smart Images
Figure 0007865910000001 
Figure 0007865910000002 
Figure 0007865910000003
Abstract
Description
Technical Field
[0001] The present invention relates to an RFID gate system.
Background Art
[0002] Conventionally, in logistics and the like, when managing articles, a gate is provided, an RFID tag is attached to the articles passing through it, radio waves are radiated by an RFID tag reader / writer provided inside the gate, and article management is performed by reading the passing RFID tags. When constructing a gate for RFID, a material that does not transmit radio waves, such as a metal plate or metal foil, is used to prevent the radiation (leakage) of radio waves outside the gate.
[0003] For example, a technology of an RFID gate system including a metal gate having a hollow cylindrical wall and one or more antennas installed on the inner surface of the cylindrical wall that radiate radio waves at a preset transmission output and communicate with an RFID tag provided on an article when the article passes through the inside of the gate has been proposed (see, for example, Patent Document 1).
Prior Art Documents
Patent Documents
[0004]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0005] However, when the gate is simply composed of a material that does not transmit radio waves as in the conventional technology, radio waves reflected by the wall of the gate facing the RFID tag reader / writer and the like diffuse outside the gate. For this reason, there has been a problem that RFID tags that do not need to be read and exist outside the gate are read. In order to solve this problem, it is conceivable to configure the wall of the gate with a radio wave absorber, but the radio wave absorber is expensive and there is a problem that the product cost increases.
[0006] In view of the above problems, the present invention aims to provide an RFID gate system that can suppress the leakage of radio waves outside the gate and suppress the reading of unnecessary RFID tags outside the gate. [Means for solving the problem]
[0007] To achieve the above objective, the RFID gate system of the present invention comprises a gate with openings at both ends through which an article can pass; at least one antenna that emits radio waves to an RFID tag on the article when it passes through the gate; and a shielding plate (reflector) that prevents the radio waves emitted from the antennas from leaking outside the gate, wherein the shielding plate (reflector) is configured to reflect radio waves in a specific direction. [Effects of the Invention]
[0008] According to the present invention, it is possible to suppress the leakage of radio waves outside the gate and to suppress the reading of unnecessary RFID tags outside the gate. [Brief explanation of the drawing]
[0009] [Figure 1] This is an elevation view showing an example of the configuration of the RFID gate system in this embodiment. [Figure 2] This is a top view showing an example of the configuration of the RFID gate system in this embodiment. [Figure 3] This is a top view illustrating the overview of a conventional RFID gate system. [Figure 4] This is a top view showing an example of the RFID gate system of Example 1. [Figure 5] This is a top view showing an example of the RFID gate system of Example 2. [Figure 6] This is a top view showing an example of the RFID gate system of Example 3. [Figure 7] This is a top view showing an example of the RFID gate system of Example 4. [Figure 8] This is a top view showing an example of the RFID gate system of Example 5. [Figure 9] This is a top view showing an example of the RFID gate system of Example 6. [Figure 10] This is a top view showing an example of the RFID gate system of Example 7. [Figure 11] This is a top view showing an example of the RFID gate system of Example 8. [Modes for carrying out the invention]
[0010] The RFID gate system including the antenna according to this embodiment will be described below with reference to the drawings. Figure 1 is an elevation view showing an example of the configuration of the RFID gate system 100 in this embodiment. Figure 2 is a top view showing an example of the configuration of the RFID gate system 100 in this embodiment.
[0011] The RFID gate system 100 is used to manage the number of items (m) that are subject to item management as they pass through the gate.
[0012] The RFID gate system 100 comprises gates 10 and 11, antennas 20 and / or 21, shielding plates (reflectors) 31 and / or 30. Gates 10 and 11 are connected to each other through a frame 12. In Figure 1, gates 10 and 11 are connected to each other through the frame 12, but this is not limited to this, and they may be formed independently. Note that the frame 12 is omitted in Figures 2 and onward.
[0013] Gate 10 is formed by a gate-shaped structure with openings at least at both ends through which the article 200 can pass. Gates 10 and 11 are configured to allow the article 200 to pass through by a belt conveyor, a handcart, or an automated transport device such as a robot. In Figure 2, the shape of gates 10 and 11 is not particularly limited as long as they are configured to allow the article 200 to pass through.
[0014] Antenna 20 radiates radio waves within gates 10 and 11, and detects the passage of article 200 by detecting RFID tag 50 provided on article 200 when article 200 passes through within gates 10 and 11. Antenna 20 is constituted by, for example, an RFID tag reader / writer. In the embodiments of FIGS. 1 and 2, only one antenna 20 is described, but this is not the case. For example, at least one or more antennas may be provided. For example, two or more antennas 20 may be arranged.
[0015] Shielding plates (reflective plates) 30 and 31 prevent radio waves radiated from antenna 20 from leaking outside the gate. As the material of shielding plates (reflective plates) 30 and 31, a material having radio wave shielding performance such as a metal plate or a metal foil is used. In particular, a material having excellent radio wave shielding performance is used as the material.
[0016] FIG. 3 is a top view showing an overview of a conventional RFID gate system 300. In the conventional RFID gate system 300, since radio waves radiated from antenna 120 are diffused, they are reflected up to regions R1 and R2 beyond gates 110 and 110' constituting the RFID gate system 300. As a result, when gates 110 and 110' are constituted by a material that does not transmit radio waves outside the gates, radio waves reflected by the wall of gate 110' facing the RFID tag reader / writer which is antenna 20, etc. diffuse outside gates 110 and 110'. For this reason, there was a problem that RFID tags that do not need to be read existing in regions R1 and R2 outside the gate are read. Therefore, in the present embodiment, as shown in FIGS. 4 to 11 described later, shielding plate (reflective plate) 31 and / or shielding plate (reflective plate) 30 is configured in a shape that reflects radio waves radiated from antenna 20 and / or antenna 21 in a specific direction.
[0017] Referring to FIGS. 4 to 11, shielding plates (reflective plates) 30 and 31 constituting the RFID gate system 100 of the present embodiment will be described.
[0018] (Example 1) Figure 4 is a top view showing an example of the RFID gate system 100 of Embodiment 1. In the embodiment of Figure 4, the shielding plate (reflector) 31 is configured in a polynomial shape with the antenna 20 as the focal point. More preferably, the shielding plate (reflector) 31 is configured in a quadratic shape with the antenna 20 as the focal point. The antenna 20 is positioned on the gate 11 side of the pair of gates 10 and 11. That is, the shielding plate (reflector) 31 is positioned on the opposite side of the antenna 20.
[0019] In Example 1, the radio waves w1 diffused at a wide angle from the antenna 20 are reflected by the shielding plate (reflector) 31 from the gate 11 side toward the gate 10 side so as not to leak outside the gates 10 and 11. As a result, the radio waves w1 are prevented from leaking outside the gates 10 and 11, and misreading of RFID tags 50 located outside the gates 10 and 11 can be suppressed. As a result, the reading accuracy of the RFID tags 50 can be improved.
[0020] Furthermore, the radio waves w2 diffused behind the antenna 20 are also reflected by the shielding plate (reflector) 31 so as not to travel outside the gates 10 and 11. As a result, the radio waves w2 are prevented from leaking outside the gates 10 and 11, and misreading of RFID tags 50 located outside the gates 10 and 11 can be suppressed. As a result, the reading accuracy of the RFID tags 50 can be improved. In addition, a shielding plate (reflector) not shown may be placed on the back side of the antenna 20. In this case, the shielding plate (reflector) not shown will reflect the radio waves from the gate 10 side towards the gate 11 side so as not to leak outside the gates 10 and 11. As a result, the radio waves w2 are prevented from leaking outside the gates 10 and 11, and misreading of RFID tags 50 located outside the gates 10 and 11 can be suppressed.
[0021] (Example 2) Figure 5 is a top view showing an example of the RFID gate system 100 of Embodiment 2. In the embodiment shown in Figure 5, the shielding plate (reflector) 31 is configured in a bent shape in which both ends of the shielding plate (reflector) 31 are bent toward the antenna 20. The antenna 20 is positioned on the gate 11 side of the pair of gates 10 and 11. That is, the shielding plate (reflector) 31 is positioned opposite the antenna 20.
[0022] In Example 2, the radio waves w3 diffused at a wide angle from the antenna 20 are reflected from the gate 11 side toward the gate 10 side by the shielding plate (reflector) 31 so as not to leak outside the gates 10 and 11. As a result, the leakage of radio waves w3 outside the gates 10 and 11 is prevented, and misreading of RFID tags 50 located outside the gates 10 and 11 can be suppressed. As a result, the reading accuracy of the RFID tags 50 can be improved.
[0023] Furthermore, the radio waves w4 diffused behind the antenna 20 are reflected by the shielding plate (reflector) 31 so as not to travel outside the gates 10 and 11. As a result, the radio waves w4 are prevented from leaking outside the gate 10, and misreading of RFID tags 50 located outside the gate 10 can be suppressed. Consequently, the reading accuracy of the RFID tags 50 can be improved. In addition, since the reading accuracy of the RFID tags 50 can be improved simply by bending the shielding plate (reflector) 30, the manufacturing cost of the RFID gate system 100 can be reduced.
[0024] (Example 3) Figure 6 is a top view showing an example of the RFID gate system 100 of Embodiment 3. In the embodiment shown in Figure 6, the shielding plate (reflector) 31 is configured in a Fresnel shape. The antenna 20 is positioned on the gate 11 side of the pair of gates 10 and 11. That is, the shielding plate (reflector) 31 is positioned on the opposite side of the antenna 20.
[0025] In Example 3, the radio waves w5 diffused at a wide angle from the antenna 20 are reflected from the gate 11 side toward the gate 10 side by the Fresnel-shaped shielding plate (reflector) 31 so as not to leak outside the gates 10 and 11. As a result, the radio waves w5 are prevented from leaking outside the gates 10 and 11, and misreading of RFID tags 50 located outside the gates 10 and 11 can be suppressed. As a result, the reading accuracy of the RFID tags 50 can be improved. Furthermore, because the shielding plate (reflector) 31 is formed in a Fresnel shape, the thickness of the shielding plate (reflector) 31 can be made thinner than if it were a quadratic function shape or a folded shape, allowing for the creation of a compact RFID gate system 100.
[0026] (Example 4) Figure 7 is a top view showing an example of the RFID gate system 100 of Embodiment 4. In the embodiment of Figure 7, the shielding plates (reflectors) 30 and 31 are composed of a pair of Fresnel shapes. More preferably, a plurality of Fresnel-shaped shielding plates (reflectors) 30 and 31 are arranged facing each other toward the RFID tag to be read. The antenna 20 is positioned on the gate 11 side of the pair of gates 10 and 11, and the antenna 20 is positioned on the gate 10 side of the pair of gates 10 and 11. That is, the shielding plate (reflector) 31 is positioned opposite the antenna 20, and the shielding plate (reflector) 30 is positioned opposite the antenna 21.
[0027] In Example 4, the radio waves w5 diffused at a wide angle from the antenna 20 are reflected from the gate 11 side toward the gate 10 side by the Fresnel-shaped shielding plate (reflector) 31 so as not to leak outside the gates 10 and 11. As a result, the radio waves w5 are prevented from leaking outside the gates 10 and 11, and misreading of the RFID tag 50 located outside the gate 10 can be suppressed. As a result, the reading accuracy of the RFID tag 50 can be improved.
[0028] Furthermore, the radio waves w6, which are widely diffused from the antenna 21, are reflected by the shielding plate (reflector) 30 from the gate 10 side towards the gate 11 side to prevent them from leaking outside the gates 10 and 11. As a result, the radio waves w6 are prevented from leaking outside the gates 10 and 11, and misreading of RFID tags 50 located outside the gates 10 and 11 can be suppressed. Consequently, the reading accuracy of the RFID tags 50 can be improved.
[0029] Furthermore, since the Fresnel-shaped shielding plates (reflectors) 30 and 31 are positioned opposite each other, the radio waves w5 diffused from the antenna 20 and reflected by the shielding plate (reflector) 31, and the radio waves w6 diffused from the antenna 21 and reflected by the shielding plate (reflector) 30, are reflected again by the opposing Fresnel-shaped shielding plates (reflectors) 30 and 31 toward the center of the gates 10 and 11, from the gate 10 side toward the gate 11 side and / or from the gate 11 side toward the gate 10 side. As a result, the RFID tag 50 can be read multiple times, thereby improving reading accuracy. In addition, since the shielding plates (reflectors) 30 and 31 are formed in a Fresnel shape, the thickness of the shielding plate (reflector) 31 can be made thinner than if it were a quadratic function shape or a folded shape, allowing the RFID gate system 100 to be made compact.
[0030] (Example 5) Figure 8 is a top view showing an example of the RFID gate system 100 of Embodiment 5. In the embodiment shown in Figure 8, the shielding plate (reflector) 30 is formed by connecting triangles in a continuous shape (hereinafter also referred to as "continuous triangular shape"). The antenna 20 is positioned on the gate 11 side of the pair of gates 10 and 11. That is, the shielding plate (reflector) 31 is positioned on the opposite side of the antenna 20. In this embodiment, a continuous triangular shape refers to a shape formed at a predetermined angle so that the radio waves w7 emitted from the antenna 20 are reflected by the shielding plate (reflector) 31 and directed toward a specific location R3 located between the gates 10 and 11.
[0031] In Example 5, the radio waves w7 diffused at a wide angle from the antenna 20 are reflected from the gate 11 side toward the gate 10 side by the continuous triangular shielding plate (reflector) 31 so as not to leak outside the gates 10 and 11. This allows the radio waves w7 emitted from the antenna 20 to be collected at a specific location R3 where the RFID tag 50 is placed. As a result, it is possible to prevent the radio waves w7 from leaking outside the gates 10 and 11 and to improve the reading accuracy of the RFID tag 50.
[0032] (Example 6) Figure 9 is a top view showing an example of the RFID gate system 100 of Embodiment 6. In the embodiment shown in Figure 9, the shielding plates (reflectors) 30 and 31 are configured in a continuous triangular shape. More preferably, multiple continuous triangular shielding plates (reflectors) 30 and 31 are arranged facing each other toward a specific location R3 where the RFID tag 50 to be read is placed.
[0033] In Example 6, the radio waves w7 diffused at a wide angle from the antenna 20 are reflected by the continuous triangular shielding plates (reflectors) 30 and 31 from the gate 11 side to the gate 10 side and from the gate 10 side to the gate 11 side, so as not to leak outside the gates 10 and 11. As a result, the radio waves w7 emitted from the antenna 20 can be collected at a specific location R3 where the RFID tag 50 is placed, and the radio waves w8 emitted from the antenna 21 can also be collected at a specific location R3 where the RFID tag 50 is placed. As a result, the leakage of radio waves w7 and w8 outside the gates 10 and 11 is prevented, and the reading accuracy of the RFID tag 50 can be improved.
[0034] Furthermore, since the continuous triangular shielding plates (reflectors) 30 and 31 are positioned opposite each other, the radio waves w7 emitted from antenna 21 and the radio waves w8 emitted from antenna 20 are reflected again to the specific location R3 where the RFID tag 50 is placed by the opposing continuous triangular shielding plates (reflectors) 30 and 31. As a result, the RFID tag 50 can be read multiple times, thereby improving reading accuracy.
[0035] (Example 7) Figure 10 is a top view showing an example of the RFID gate system 100 of Embodiment 7. In the embodiment shown in Figure 10, the shielding plate (reflector) 31 is configured to have a shape that can be adjusted toward the RFID tag 50 to be read. The antenna 20 is positioned on the gate 11 side of the pair of gates 10 and 11. That is, the shielding plate (reflector) 31 is positioned opposite the antenna 20.
[0036] In Embodiment 7, the radio waves w9 diffused at a wide angle from the antenna 20 are reflected from the gate 10 side towards the gate 11 side by a variable-shaped shielding plate (reflector) 31 so as not to leak outside the gates 10 and 11. The angle of the shielding plate (reflector) 31 is variable so as to be directed toward a specific location R4 where the RFID tag 50 to be read is located. Therefore, the radio waves w9 emitted from the antenna 20 can be reflected by the shielding plate (reflector) 31 toward the specific location R4 where the RFID tag 50 to be read is located. As a result, the radio waves w9 are prevented from leaking outside the gates 10 and 11, and misreading of RFID tags 50 located outside the gates 10 and 11 can be suppressed. As a result, the reading accuracy of the RFID tag 50 can be improved.
[0037] Furthermore, since the shielding plate (reflector) 31 is variable, even if the specific location R4 where the RFID tag 50 to be read is placed moves (for example, moves upward in Figure 10), the direction (angle) of the radio waves w9 reflected from the gate 11 side toward the gate 10 side can be changed to follow the movement of the RFID tag 50. This makes it possible to make the radio waves w9 reflected from the gate 11 side toward the gate 10 side follow the specific location R4 where the RFID tag 50 to be read is placed. As a result, the radio waves w9 emitted from the antenna 20 can be reflected by the shielding plate (reflector) 31 toward the specific location R4 where the RFID tag 50 to be read is placed. As a result, it is possible to prevent the radio waves w9 from leaking outside the gates 10 and 11, and to suppress misreading of RFID tags 50 that are outside the gates 10 and 11. As a result, the reading accuracy of the RFID tag 50 can be improved.
[0038] (Example 8) Figure 11 is a top view showing an example of the RFID gate system 100 of Embodiment 8. In the embodiment shown in Figure 11, the shielding plates (reflectors) 30 and 31 are configured to be variable in direction toward the RFID tag 50 to be read. More preferably, multiple variable shielding plates (reflectors) 30 and 31 are arranged facing each other toward the RFID tag 50 to be read. The antenna 20 is positioned on the gate 11 side of the pair of gates 10 and 11. That is, the shielding plate (reflector) 31 is positioned opposite the antenna 20. The antenna 21 is positioned on the gate 10 side of the pair of gates 10 and 11. That is, the shielding plate (reflector) 30 is positioned opposite the antenna 21.
[0039] In Example 8, the radio waves w9 diffused at a wide angle from the antenna 20 are reflected from the gate 11 side toward the gate 10 side by a variable-shaped shielding plate (reflector) 31 so as not to leak outside the gates 10 and 11. Similarly, the radio waves w10 diffused at a wide angle from the antenna 21 are reflected from the gate 10 side toward the gate 11 side by a variable-shaped shielding plate (reflector) 30 so as not to leak outside the gates 10 and 11. The angle of the shielding plate (reflector) 31 is variable so as to be directed toward a specific location R4 where the RFID tag 50 to be read is located. In the same way, the angle of the shielding plate (reflector) 30 is variable so as to be directed toward a specific location R4 where the RFID tag 50 to be read is located. Therefore, the radio waves w9 emitted from the antenna 20 can be reflected by the shielding plate (reflector) 31 toward a specific location R4 where the RFID tag 50 to be read is located. Similarly, the radio waves w10 emitted from the antenna 21 can be reflected by the shielding plate (reflector) 30 towards a specific location R4 where the RFID tag 50 to be read is located. As a result, the radio waves w9 and w10 are prevented from leaking outside the gates 10 and 11, and misreading of the RFID tag 50 located outside the gates 10 and 11 can be suppressed. Consequently, the reading accuracy of the RFID tag 50 can be improved.
[0040] Furthermore, since the shielding plates (reflectors) 30 and 31 are variable, even if the specific location R4 where the RFID tag 50 to be read is placed moves (for example, moves upward in Figure 10), the direction in which the radio waves w9 and w10 are reflected can be changed to follow the movement of the RFID tag 50. This allows the reflected radio waves w9 and w10 to follow the specific location R4 where the RFID tag 50 to be read is placed. Therefore, the radio waves w9 and w10 emitted from the antenna 20 can be reflected by the shielding plates (reflectors) 30 and 31 towards the specific location R4 where the RFID tag 50 to be read is placed. As a result, it is possible to prevent the radio waves w9 and w10 from leaking outside the gates 10 and 11, and to suppress misreading of RFID tags 50 located outside the gates 10 and 11. As a result, the reading accuracy of the RFID tag 50 can be improved.
[0041] It should be noted that the present invention is not limited to the embodiments described above, and the components can be modified and implemented in a manner that does not depart from the spirit of the invention during implementation. Furthermore, various inventions can be formed by appropriately combining the multiple components disclosed in the above embodiments. For example, all the components shown in the embodiments may be combined as appropriate. Moreover, components from different embodiments may be combined as appropriate. It goes without saying that various modifications and applications are possible within the scope that does not depart from the spirit of the invention. [Explanation of symbols]
[0042] 10, 11: Gate 12: Frame 20, 21: Antenna 30, 31: Shielding plate (reflection plate) 50: RFID tags 100: RFID gate system 110, 110': Gate 200: Goods
Claims
1. A gate with openings at both ends through which items can pass, When passing through the gate, at least one antenna emits radio waves to the RFID tag attached to the item, An RFID gate system comprising a shielding plate for preventing the radio waves emitted from the antenna from leaking outside the gate, The shielding plate is configured to reflect radio waves in a specific direction, The shape is a polynomial function shape with the position of the antenna as the focal point, a quadratic function shape with the position of the antenna as the focal point, or a continuous triangular shape. An RFID gate system characterized by the following features.
2. Multiple shielding plates are arranged facing the RFID tag to be read. The RFID gate system according to feature 1.