JP6106138B2 - Radiated radio wave detector - Google Patents

Description

  Embodiments described herein relate generally to a radiation wave detection device.

  In recent years, RFID (Radio Frequency IDentification) technology has been used in the field of inventory management of goods. That is, a technology for grasping inventory by attaching an RF tag to a product and reading the RF tag with an RFID reader has been put into practical use. The RFID reader radiates a radio wave toward the RF tag, and reads the data in the built-in memory of the RF tag by receiving the radio wave emitted by the RF tag that has received the radio wave.

  If the RFID reader does not emit radio waves correctly, the RF tag data cannot be read. However, radio waves are invisible. For this reason, inspecting whether the RFID reader correctly emits radio waves requires a device that shows a predetermined reaction that can be recognized by a person when receiving the radio waves.

  On the other hand, the conventional RFID reader separates the RFID module that reads data from the radio wave received by the antenna separately from the antenna so as not to impair the characteristics of the antenna that handles radio waves with the RF tag. Such an apparatus is not easy to use and is required to improve operability.

  The RFID reader is used for, for example, an inventory of an apparel store, but an apparatus that may be used in a store in operation is required to have an appearance that does not impair the atmosphere of the store.

  The problem to be solved by the present invention is to provide a radiated radio wave detection device that can suitably perform a check in a situation where a radio wave radiance check assumed for an RFID reader that is easy to use due to an unconventional configuration is required. That is.

  The radiation wave detection device of the embodiment is a radiation wave detection device used by being attached to an RFID reader, and includes a first antenna, a second antenna, a first notification unit, a second notification unit, and an attachment member. And comprising. The first antenna has a metal bar shape with the longitudinal direction oriented in the vertical direction. The second antenna has a metal bar shape with the longitudinal direction oriented in the lateral direction. The first notification unit receives a radio wave radiated from the RFID reader and shows a predetermined reaction that can be recognized by a person using the power generated by the first antenna. The second notification unit receives a radio wave radiated from the RFID reader and shows a predetermined reaction that can be recognized by a person using the power generated by the second antenna. The attachment member removably attaches the first antenna and the second antenna to the RFID reader.

FIG. 1 is a perspective view illustrating an external appearance of an RFID reader according to an embodiment from the front side. FIG. 2 is a perspective view showing the appearance of the RFID reader according to the embodiment from the back side. FIG. 3 is a diagram illustrating an example of a usage state of the RFID reader according to the embodiment. FIG. 4 is a perspective view illustrating an appearance of an antenna device built in the RFID reader according to the embodiment. FIG. 5 is a block diagram illustrating a functional configuration of the RFID reader according to the embodiment. FIG. 6 is a diagram illustrating a concept and a shape example of a general circularly polarized antenna. FIG. 7 is a graph showing characteristics of the antenna of FIG. FIG. 8 is a perspective view illustrating an appearance and a usage state of the radiated wave detection device of the embodiment from the front side. FIG. 9 is a perspective view showing an appearance and a usage state of the radiated wave detection device of the embodiment from the back side. FIG. 10 is a schematic diagram illustrating an example of a circuit diagram of the radiated wave detection device of the embodiment.

  Embodiments will be described with reference to the drawings. 1 and 2 are perspective views showing an external appearance of an RFID handy (RFID reader) 100 according to the embodiment from the front side and the back side. FIG. 3 is a diagram illustrating an example of a usage state of the RFID handy 100. FIG. 4 is a front view showing an appearance of the antenna device 200 built in the RFID handy 100. FIG. 5 is a block diagram showing a functional configuration of the RFID handy 100.

  The RFID handy 100 includes an antenna device 200 and an exterior 300. The exterior 300 includes a housing 310, a grip 320, and an external device holding unit 330. The RFID handy 100 reads data in a memory built in an RF tag (not shown) located on the front 101 side. The RF tag is attached to an article to be managed.

  The casing 310 has a thin box shape, and the thickness direction is the front-rear direction, and the housing 310 is divided into two in the front-rear direction. Of each of the two divided front and rear of the housing 310, the rear side is the main body portion 311 and the front side is the lid portion 312. The main body 311 is a box with a front opening, and the antenna device 200 is accommodated therein. The lid 312 closes the opening of the main body 311.

  The lid 312 protects the antenna device 200 and improves the appearance of the RFID handy 100. The lid 312 is replaceable for changing the external appearance of the RFID handy 100 or the like. After the cover 312 is replaced, it is necessary to inspect radio waves emitted from the RFID handy device 100. Examples of adverse effects on radio waves after replacement of the lid portion 312 include short-circuiting due to mixing of metal pieces during work and the influence of the properties of the lid portion 312.

  The grip 320 is a handle of the RFID handy 100. The grip 320 is generally rod-shaped, the upper end 322 is formed flat with the grip portion 321 left, and about one third of the entire length including the upper end 322 is bent forward by a predetermined angle. The grip 320 includes a connecting portion 323 to the main body portion 311 at the upper end. The connecting portion 323 connects the grip 320 to the main body portion 311 so as to be rotatable by a predetermined angle.

  The external device holding unit 330 is provided on the upper end 322 and has a pair of clamping pieces 331 and 332. The external device holding unit 330 holds the external device S such as a smart device by the sandwiching pieces 331 and 332.

  The antenna device 200 includes a radiator 210, a power feeding plate 220, and a ground metal plate (metal member) 230. The antenna device 200 includes an RFID module 240, an I / F board 250, and a Bluetooth (registered trademark) module 260 (see FIG. 5). These (RFID module 240, I / F substrate 250, Bluetooth module 260) are arranged on the back of the ground metal plate 230.

  Radiator 210 is plate-shaped, and radiates radio waves according to power supply from power supply plate 220 and receives radio waves emitted by other devices (for example, RF tags (not shown)). The radiator 210 is a substantially circular sheet metal, and has notches 212 at a plurality of locations on the outer periphery 211. This radiator 210 radiates circularly polarized waves.

  The power feeding plate 220 supplies power to the radiator 210 by capacitive coupling. The power feeding plate 220 is a rectangular sheet metal, and is arranged to face the radiator 210 with a predetermined distance. The predetermined distance is a distance that satisfies the condition for capacitive coupling. The longitudinal direction of the power feeding plate 220 is substantially along the radial direction of the radiator 210, and the power feeding plate 220 is located from the center of the radiator 210 to the outer periphery.

  The ground metal plate 230 is a ground having a potential difference of 0 from the reference potential. The ground metal plate 230 has a thin box shape and includes a flat plate portion 231 corresponding to the bottom of the box and a side plate portion 232 surrounding the flat plate portion 231. The flat plate portion 231 and the side plate portion 232 are substantially orthogonal to each other. Further, the flat plate portion 231 has a hexagonal shape in which two opposite corners of four corners of a square are chamfered. The ground metal plate 230 is located at a position where the power supply plate 220 is sandwiched between the radiator 210 and defines a radiation range of radio waves emitted by the radiator 210. In particular, the side plate portion 232 prevents radio waves from diffusing in the plane direction of the flat plate portion 231. The flat plate portion 231 functions as a plate-like portion to which the RFID module 240 is attached.

  The RFID module 240 receives the output from the radiator 210 and reads the data in the memory built in the RF tag. The RFID module 240 is attached to a position on the ground metal plate 230 that does not face the radiator 210 (that is, the back surface of the surface facing the radiator 210). More specifically, the RFID module 240 is attached to the back surface of the ground metal plate 230. The back surface is the back surface of the surface of the flat plate portion 231 of the ground metal plate 230 that faces the power supply plate 220.

  The I / F board 250 functions as an interface between the antenna device 200 and various external devices. The Bluetooth module 260 is connected to the I / F board 250. The Bluetooth module 260 communicates with the external device S. The external device S obtains data read by the RFID module 240 via the Bluetooth module 260 and the I / F board 250.

  The RFID module 240, the I / F board 250, and the Bluetooth module 260 are obtained by attaching various chips to a printed board. Similar to the RFID module 240, the I / F substrate 250 and the Bluetooth module 260 are also attached to the back surface of the ground metal plate 230.

  The RFID module 240 and the radiator 210 are connected by a coaxial cable (not shown), so that an electrical signal can be exchanged. The flat plate portion 231 of the ground metal plate 230 has a hole (not shown) through which the coaxial cable passes.

  The antenna device 200 as described above is gain-adjusted so that characteristics suitable for work appear in the state of being housed in the exterior 300.

  A circularly polarized antenna can be obtained by cutting a rectangular or circular planar antenna. FIG. 6 is a diagram illustrating a concept and a shape example of a general circularly polarized antenna. FIG. 7 is a graph showing characteristics of the circularly polarized antenna of FIG.

  Here, circularly polarized waves will be described by taking the generally square circularly polarized antenna 400 shown in FIG. 6 as an example. However, the shape of the circularly polarized antenna is not limited to this example. The circularly polarized antenna may have a generally circular radiator 210 as shown in FIG. 4, for example, and may have other shapes.

  In the circularly polarized antenna, two currents orthogonal to each other are excited. The diagonal dimension of the circularly polarized antenna 400 shown in FIG. 6 is a, and the dimension orthogonal to the diagonal is b. In this case, in the circularly polarized antenna 400, for example, two-mode polarized waves having wavelengths a and b are excited.

  The two-mode polarized waves excited by the circularly polarized antenna 400 reach their sensitivity peaks at the frequency F1 and the frequency F2, respectively (see FIG. 7). The frequency F1 corresponds to the wavelength a, and the frequency F2 corresponds to the wavelength b.

  The frequency band X is a frequency range that exceeds the threshold of sensitivity at which communication by the circularly polarized antenna 400 is possible. That is, if the frequency is within this range, communication by the circularly polarized antenna 400 is possible regardless of the polarization direction.

  Here, the RFID handy 100 is assumed to be used in a store of an apparel store, for example, as shown in FIG. For this reason, the lid 312 can be replaced so that the appearance (for example, color and texture) can be changed according to the demand of the store. However, the replacement of the lid 312 may change the sensitivity of the antenna device 200. Furthermore, there is a possibility that the function of the RFID handy 100 cannot be sufficiently performed by replacing the lid portion 312. For this reason, when the lid portion 312 is replaced, it is necessary to confirm the output.

  FIG. 8 is a perspective view showing the appearance and use state of the radiated radio wave detection device 500 from the front side. FIG. 9 is a perspective view showing the appearance and use state of the radiated wave detection device 500 from the back side.

  The radiated radio wave detection device 500 is used by being attached to the front surface of the housing 310 of the RFID handy 100. The radiated radio wave detection device 500 includes a first antenna 510, a second antenna 520, a first notification unit 530, a second notification unit 540, and an attachment member 550.

  Hereinafter, for convenience of explanation, the first antenna 510 and the second antenna 520 may be collectively referred to as antennas 510 and 520. Similarly, for convenience of explanation, the first notification unit 530 and the second notification unit 540 may be collectively referred to as notification units 530 and 540.

  The first antenna 510 and the second antenna 520 are metal rod-shaped members. The first antenna 510 is arranged with the longitudinal direction oriented in the vertical direction, and the second antenna 520 is arranged with the longitudinal direction oriented in the horizontal direction. The first antenna 510 and the second antenna 520 intersect at the center of each other to form a cross. The second antenna 520 is fixed to the first antenna 510. The first antenna 510 and the second antenna 520 receive polarized waves that are substantially orthogonal to each other.

  The antennas 510 and 520 receive electric waves radiated from the RFID handy 100 and generate electric power.

  The first notification unit 530 uses the electric power generated by the first antenna 510 to show a predetermined reaction that can be recognized by a person. That is, the first notification unit 530 notifies the presence of a radiated radio wave that can be received by the first antenna 510. The first notification unit 530 includes, for example, an LED (Light Emitting Diode) attached to the first antenna 510, and turns on the LED with electric power from the first antenna 510.

  The second notification unit 540 uses the electric power generated by the second antenna 520 to show a predetermined reaction that can be recognized by a person. That is, the second notification unit 540 notifies the presence of a radiated radio wave that can be received by the second antenna 520. The 2nd alerting | reporting part 540 has LED attached to the 2nd antenna 520, for example, and makes this LED light with the electric power from the 2nd antenna 520. FIG.

  The attachment member 550 attaches the first antenna 510 and the second antenna 520 to the RFID handy 100 in a detachable manner. The attachment member 550 includes a plurality of hook members 551 to 554 having elasticity and a stay 555. The stay 555 is a rod-shaped member, and holds the first antenna 510 so as to hang from the center. The hook members 551 and 552 have one end fixed to the stay 555. The hook members 553 and 554 have one end fixed to the second antenna 520. As described above, the hook members 551 to 554 are directly or indirectly fixed to the first antenna 510 or the second antenna 520.

  The attachment member 550 attaches the antennas 510 and 520 to the RFID handy 100 when the hook members 551 to 554 are hooked on the RFID handy 100. In attachment, the attachment member 550 is integrated with the antennas 510 and 520 and holds the housing 310 from the front.

  FIG. 10 is a schematic diagram illustrating an example of a circuit diagram of the radiated radio wave detection device 500. The antennas 510 and 520 include a pair of antenna units 501 and 502, respectively. In addition, the notification units 530 and 540 include a rectifier circuit 503 and an LED 504.

  The antenna units 501 and 502 are dipole antenna type antenna devices. Each of the antenna units 501 and 502 has a length of ¼ of the wavelength λ of the radio wave included in the frequency band to be transmitted and received. The rectifier circuit 503 determines the flow direction of the current flowing through the LED 504. The LED 504 receives the power obtained by the antenna units 501 and 502 and shines.

  In such a configuration, the RFID handy 100 reads data in a memory built in an RF tag (not shown) located on the front surface 101 side.

  The operator holds the grip 320 and points the front face 101 toward the management target article (not shown). An RF tag is attached to the article to be managed. The RF tag receives radio waves radiated from the radiator 210 and emits radio waves. And the radiator 210 which received the electromagnetic wave which RF tag emitted outputs to the RFID module 240 via a coaxial cable according to the electromagnetic wave from RF tag. The RFID module 240 receives the output from the radiator 210 and reads data in a memory built in the RF tag. The output from the radiator 210 is radio waves from the RF tag input through the radiator 210 and the coaxial cable.

  The radiated radio wave detector 500 is used when it is necessary to inspect whether or not the RFID handy 100 as described above emits radio waves normally. The case where inspection is required is assumed, for example, when the lid 312 is replaced.

  The antennas 510 and 520 included in the radiated radio wave detection device 500 obtain power from radio waves radiated from the RFID handy 100 and supply the power to the notification units 530 and 540. The notification units 530 and 540 illuminate when sufficient power is supplied to emit light. Thereby, the alerting | reporting parts 530 and 540 alert | report that the electric power exceeding a predetermined threshold value was supplied. This notification content indicates that the antennas 510 and 520 have obtained power exceeding a predetermined threshold. This indicates that the antennas 510 and 520 have received a predetermined polarization, that is, the RFID handy 100 has transmitted a predetermined polarization.

  The radiated radio wave detection device 500 is used for an operation for checking whether or not the radio wave emitted from the RFID handy device 100 is in a predetermined state, and adjusting if it is not in the predetermined state. At that time, the radiated radio wave detection device 500 is attached to a predetermined position in front of the RFID handy 100.

  According to the radiation wave detection device 500 having such a configuration, the following effects can be obtained.

  The radiated radio wave detection device 500 can detect and notify the two-mode polarization included in the circular polarization radiated from the antenna device 200 included in the RFID handy 100 in one operation. As a comparative example, a case where only one of the antennas 510 and 520 is provided will be described. In this case, after confirming the output for one of the two modes, the antenna is rotated 90 degrees to confirm the other output. On the other hand, according to the present embodiment, the confirmation of the output of both polarizations can be completed with a single operation.

  In addition, since the attachment member 550 can detect the RFID handy 100 in a certain positional relationship, a stable detection state can be created.

  In the present embodiment, the first antenna 510 and the second antenna 520 form a cross, but the present invention is not limited to this. For example, the first antenna and the second antenna may form an L shape.

  Further, in the present embodiment, the second antenna 520 is fixed to the first antenna 510, but the implementation is not limited thereto. For example, even if the first antenna 510 and the second antenna 520 are not fixed, the attachment member 550 may be configured so that the antennas 510 and 520 can be attached to the RFID handy 100.

  Moreover, in this embodiment, although the alerting | reporting parts 530 and 540 visualized the presence of the electromagnetic wave by lighting LED, in implementation, you may use a buzzer instead of LED. In the case of a buzzer, the presence of radiated radio waves is informed by sound.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

100 ... RFID handy (RFID reader), 101 ... front,
200 ... antenna device,
210 ... radiator, 211 ... outer periphery, 212 ... notch,
220 ... feed plate,
230 ... Ground sheet metal, 231 ... Plate portion, 232 ... Side plate portion,
240 ... RFID module,
250 ... I / F board,
260 ... Bluetooth module,
300 ... exterior,
310 ... Case, 311 ... Main body, 312 ... Cover,
320 ... grip, 321 ... grip part, 322 ... upper end part, 323 ... connection part,
330 ... External device holder, 331, 332 ... Nipping piece,
400 ... Circularly polarized antenna,
500 ... Radiated radio wave detection device,
510 ... first antenna, 520 ... second antenna,
530 ... first notification unit, 540 ... second notification unit,
550 ... Mounting member, 551-554 ... Hook member, 555 ... Stay,
Reference numerals 501 and 502 are antenna portions, 503 are rectifier circuits, and 504 are LEDs.

JP 2009-20856 A

Claims (5)

A radiated radio wave detector used by being attached to an RFID reader,
A metal rod-shaped first antenna with the longitudinal direction oriented in the longitudinal direction;
A metal rod-shaped second antenna with the longitudinal direction oriented laterally;
A first notification unit that receives a radio wave radiated from the RFID reader and shows a predetermined reaction that can be recognized by a person using the power generated by the first antenna;
A second notification unit that receives a radio wave radiated from the RFID reader and shows a predetermined reaction that can be recognized by a person using the power generated by the second antenna;
An attachment member for detachably attaching the first antenna and the second antenna to the RFID reader;
A radiated radio wave detector.   2. The radiated radio wave detection device according to claim 1, wherein the first antenna and the second antenna intersect with each other at a center portion to form a cross. The attachment member has a plurality of elastic hook members that are directly or indirectly fixed to the first antenna or the second antenna, and the hook members are hooked on the RFID reader. The radiated radio wave detection device according to claim 1, wherein the first antenna and the second antenna are attached to the RFID reader. The first notification unit or the second notification unit, as the predetermined reaction, makes the presence of a radio wave visible by turning on an LED, or notifies the presence of a radio wave by sounding a buzzer. The radiated radio wave detection device according to any one of claims 1 to 3. The radiated radio wave detection device according to claim 1, wherein the attachment member attaches the first antenna and the second antenna to a front surface of the RFID reader.

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