Wireless tag reading device

Abstract

The present invention discloses a wireless tag reading device, which can easily read wireless tags that are difficult to read, and the wireless tag reading device includes: a tunnel, multiple antennas, a reading control unit, and a holding unit. The antenna radiates radio waves for reading wireless tags into the tunnel. The reading control unit enables the multiple antennas to radiate the radio waves. The holding unit can detachably hold any one of the multiple antennas.

Description

[0001] This application claims priority from Japanese patent application No. JP2019-166756, filed on September 13, 2019, and cites the contents of the aforementioned application, the disclosure of which is hereby incorporated by reference in its entirety. Technical Field

[0002] An embodiment of the present invention relates to a wireless tag reading device. Background Art

[0003] Conventionally, in an RFID (Radio Frequency IDentifier) ​​system, a technology for reading a wireless tag attached to an object passing through a door or the like is known.

[0004] However, due to various factors, there may be a case where reading of some of the wireless tags passing through the door fails. Summary of the invention

[0005] In view of the above problems, the technical problem to be solved by the present invention is to provide a wireless tag reading device that can easily read wireless tags that are difficult to read.

[0006] To solve the above problem, one embodiment of the present invention provides a wireless tag reading device, comprising: a tunnel, a plurality of antennas, a reading control unit, and a holding unit. The antenna radiates radio waves for reading wireless tags into the tunnel. The reading control unit causes the plurality of antennas to radiate the radio waves. The holding unit detachably holds any one of the plurality of antennas.

[0007] According to the wireless tag reading device described above, a wireless tag reading device capable of easily reading a wireless tag that is difficult to read is provided.

[0008] The wireless tag reading device described above may further include a detection unit configured to detect that the antenna has been removed from the holding unit.

[0009] According to the wireless tag reading device described above, it is possible to detect the state of the detachable antenna.

[0010] In the wireless tag reading device described above, when the detection unit detects that the antenna has been detached from the holding unit, the reading control unit causes the detached antenna to radiate the radio wave.

[0011] According to the wireless tag reading device described above, the antenna can be caused to radiate radio waves in response to the operator removing the antenna.

[0012] In the wireless tag reading device described above, the reading control unit may prevent the antenna from radiating radio waves when the detection unit does not detect that the antenna has been detached from the holding unit.

[0013] According to the wireless tag reading device described above, it is possible to save the power consumed by the detachable antenna.

[0014] In the wireless tag reading device described above, when the reading control unit causes the removed antenna to radiate the radio wave, the reading control unit does not cause the other antennas to radiate the radio wave.

[0015] According to the wireless tag reading device described above, when the removed antenna is used, interference with radio waves from other antennas can be avoided.

[0016] In the wireless tag reading device described above, the holding portion has a shape that allows the detachable antenna to be mounted by sliding it from above.

[0017] According to the wireless tag reading device described above, the antenna can be easily mounted on the holding portion.

[0018] In the wireless tag reading device described above, the holding portion includes a connecting portion connected to the tunnel, a mounting portion to which the detachable antenna is mounted, and a hinge connecting the connecting portion and the mounting portion, and the hinge holds the mounting portion at an arbitrary angle.

[0019] According to the wireless tag reading device described above, the antenna can be directed in any direction.

[0020] In the wireless tag reading device described above, the detachable antenna has a handle.

[0021] According to the wireless tag reading device described above, the operability of the antenna can be improved.

[0022] The wireless tag reading device further includes a blocking portion formed of a radio wave shielding material that shields the radio waves radiated by the antenna, wherein the blocking portion closes the entrance and exit of the tunnel when the detection portion detects that the antenna has been removed.

[0023] According to the wireless tag reading device described above, the antenna can be made to radiate radio waves when the operator removes the antenna.

[0024] In the wireless tag reading device described above, the reading control unit may cause the removed antenna to radiate the radio wave when the blocking unit closes the entrance.

[0025] According to the wireless tag reading device described above, it is possible to prevent a wireless tag located outside from being read. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Below, the wireless tag reading device involved in the embodiment is described with reference to the accompanying drawings. When considered in conjunction with the accompanying drawings, by referring to the detailed description below, the present invention can be more completely and better understood and many of the accompanying advantages can be easily known, but the drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention, wherein:

[0027] Figure 1 is a perspective view showing an example of the appearance of the wireless tag reading device involved in this embodiment;

[0028] Figure 2 is a side sectional view showing an example of the appearance of the wireless tag reading device involved in this embodiment;

[0029] Figure 3 is a front cross-sectional view showing an example of the appearance of the wireless tag reading device involved in this embodiment;

[0030] Figure 4 is a perspective view showing an example of the appearance of the entrance blocking portion of the wireless tag reading device involved in this embodiment in a closed state as viewed from the entrance side;

[0031] Figure 5 is a perspective view showing an example of the appearance of the wireless tag reading device according to the present embodiment when the exit blocking portion is in a closed state as viewed from the exit side;

[0032] Figure 6 is a main cross-sectional view showing an example of the appearance of the holding portion involved in this embodiment;

[0033] Figure 7 is a side sectional view showing an example of the appearance of the holding portion involved in this embodiment;

[0034] Figure 8 is a block diagram showing an example of the hardware configuration of the wireless tag reading device involved in this embodiment; and

[0035] Fig. 9 This is a block diagram showing an example of a characteristic functional configuration of the wireless tag reading device according to the present embodiment.

[0036] Description of Reference Numerals

[0037] 1 Wireless tag reading device 10 Tunnel

[0038] 11 First side 12 Second side

[0039] 13 above 14 blocking part

[0040] 141 entrance blocking part 142 exit blocking part

[0041] 20 Antenna 21 First Antenna

[0042] 22 Second antenna 23 Third antenna

[0043] 24 fourth antenna 30 holding portion

[0044] 31 connection part 32 hinge

[0045] 33 Installation unit 101 Control unit

[0046] 102 storage unit 103 communication interface

[0047] 104 operation unit 105 display unit

[0048] 106 Attachment and removal detection unit 107 Opening and closing drive unit

[0049] 108 Control Program 201 Handle

[0050] 1001 Reading object setting unit 1002 Notification control unit

[0051] 1003 Opening and closing control unit 1004 Reading control unit DETAILED DESCRIPTION

[0052] Hereinafter, an embodiment of the wireless tag reading device will be described in detail with reference to the accompanying drawings. In addition, the embodiment described below is an embodiment of the wireless tag reading device, and does not limit its structure, specifications, etc. The wireless tag reading device of this embodiment is an application example of a wireless tag reading device that reads wireless tags for inventory management when entering or leaving the warehouse.

[0053] Figure 1 It is a perspective view showing an example of the appearance of the wireless tag reading device 1 according to the present embodiment. Figure 2 It is a side sectional view showing an example of the appearance of the wireless tag reading device 1 according to the present embodiment. Figure 3 It is a front cross-sectional view showing an example of the appearance of the wireless tag reading device 1 according to the present embodiment.

[0054] The wireless tag reading device 1 has a tunnel 10. The tunnel 10 has a first side surface 11, a second side surface 12, and an upper surface 13. The first side surface 11 is arranged at a position opposite to the second side surface 12. In addition, the first side surface 11 and the second side surface 12 stand substantially vertically relative to the ground. Moreover, the first side surface 11 and the second side surface 12 support the upper surface 13. The upper surface 13 forms a ceiling (ceiling) of the tunnel 10.

[0055] A passage through which a flatbed truck carrying articles with wireless tags is passed is formed between the first side surface 11 and the second side surface 12. In this way, the wireless tag reading device 1 has a passage inside the tunnel 10. The operator of the wireless tag reading device 1 pushes the flatbed truck carrying articles with wireless tags to make the flatbed truck pass through the tunnel 10. The wireless tag reading device 1 reads the wireless tag when the wireless tag passes through the tunnel 10.

[0056] Here, the wireless tag is a tag such as an RF (Radio Frequency) tag. The wireless tag has an IC (Integrated Circuit) chip that stores information and an antenna. The wireless tag reads and writes the information stored in the IC chip by wirelessly communicating with the wireless tag reader 1. When the wireless tag reads the information stored in the IC chip, it sends it to the wireless tag reader 1. For example, the wireless tag contains item information that can identify the item to which the device is attached.

[0057] The wireless tag reading device 1 has a plurality of antennas for radiating radio waves for reading wireless tags inside the tunnel 10. More specifically, the wireless tag reading device 1 has a first antenna 21, a second antenna 22, a third antenna 23, and a fourth antenna 24 inside the tunnel 10. The first antenna 21 is provided in the tunnel 10 at a position approximately in the center of the conveying direction of the articles carried and conveyed by the flatbed truck and located on the first side surface 11 below the center in the height direction of the tunnel 10. The second antenna 22 is provided in the tunnel 10 at a position approximately in the center of the conveying direction of the articles carried and conveyed by the flatbed truck and located on the upper part of the first side surface 11. The third antenna 23 is provided in the tunnel 10 at a position approximately in the center of the conveying direction of the articles carried and conveyed by the flatbed truck and located on the second side surface 12 below the center in the height direction of the tunnel 10. The fourth antenna 24 is provided in the tunnel 10 at a position approximately in the center of the conveying direction of the articles carried and conveyed by the flatbed truck and located on the upper part of the second side surface 12.

[0058] The first antenna 21, the second antenna 22, the third antenna 23, and the fourth antenna 24 emit radio waves for reading wireless tags in the tunnel 10. In addition, the first antenna 21, the second antenna 22, the third antenna 23, and the fourth antenna 24 receive radio waves having item information output from the wireless tags. In addition, below, when the first antenna 21, the second antenna 22, the third antenna 23, and the fourth antenna 24 are not distinguished, they are described as antennas 20.

[0059] Here, when each antenna 20 radiates radio waves at the same time, there is often a case where the radio waves radiated from each antenna 20 interfere with each other, resulting in a failure in reading the wireless tag. Therefore, each antenna 20 radiates radio waves in a time-sharing manner from any antenna 20. In addition, in this embodiment, the case where the wireless tag reading device 1 has four antennas is used as an example for explanation. However, the number of antennas 20 can be greater than or equal to five, or less than or equal to three.

[0060] Furthermore, the wireless tag reading device 1 includes an entrance blocking unit 141 that closes the entrance of the tunnel 10 and an exit blocking unit 142 that closes the exit. Figure 4 This is a perspective view showing an example of the appearance of the wireless tag reading device 1 according to the present embodiment in a closed state when the entrance blocking portion 141 is viewed from the entrance side. Figure 5 This is a perspective view of an example of the appearance of the outlet blocking portion 142 of the wireless tag reading device 1 of this embodiment in a closed state when viewed from the outlet side. In the following, when the inlet blocking portion 141 and the outlet blocking portion 142 are not distinguished, they are described as the blocking portion 14. Figure 4 and Figure 5 As shown, the blocking part 14 is a component that closes the entrance and exit of the tunnel 10. The blocking part 14 is formed of a radio wave shielding material that blocks the radio waves radiated by the antenna 20. For example, the blocking part 14 is a shielding mesh (mesh) formed of a metal that blocks radio waves in a mesh shape. In addition, the blocking part 14 is not limited to a shielding mesh, and can be a metal plate with holes, or other components that block radio waves.

[0061] Here, the method of using the wireless tag reading device 1 is described in detail.

[0062] First, an operator using the wireless tag reader 1 inputs an object to be read by the wireless tag reader 1 to the wireless tag reader 1. That is, the operator inputs the object to be put into or taken out of the warehouse to the wireless tag reader 1. Specifically, the wireless tag reader 1 receives an operation to designate the number of object objects or the object objects stored in a server or other device.

[0063] Next, the wireless tag reader 1 causes the antenna 20 to emit radio waves in a time-sharing manner for a predetermined period. During the predetermined period, the operator pushes a flatbed truck carrying articles with wireless tags and passes through the passage inside the tunnel 10. The wireless tag reader 1 reads wireless tags passing through the tunnel 10 during the predetermined period.

[0064] The wireless tag reader 1 compares the designated target article with the article information read from the wireless tag to determine whether there is an unread wireless tag. If there is an unread wireless tag after a predetermined period of time, the wireless tag reader 1 notifies that there is an unread wireless tag.

[0065] When the operator is informed of the unread wireless tags, he returns the flatbed truck to the inside of the tunnel 10 and reads the wireless tags again with the wireless tag reader 1. However, the wireless tags that failed to be read are in a state of being difficult to read, so the first reading fails.

[0066] Here, the wireless tag reading device 1 includes a holding unit 30 (see FIG. 1 ) that detachably holds any one of the plurality of antennas 20. Figure 6 ). For example, the first antenna 21 is held by the holding portion 30. Therefore, the operator can remove the first antenna 21 from the holding portion 30 and align the first antenna 21 with the wireless tag whose reading has failed.

[0067] In addition, when the first antenna 21 is removed from the holding portion 30 and used, radio waves are radiated from the first antenna 21, and radio waves are not radiated from the second antenna 22, the third antenna 23, and the fourth antenna 24. By doing so, radio waves from other antennas do not interfere with each other. In other embodiments, when it is not possible to specify a wireless tag that has failed to be read, the wireless tag is read again by all antennas 20. By doing so, since radio waves are radiated from multiple antennas, the possibility of being able to read all wireless tags becomes higher.

[0068] Since the first antenna 21 is aligned, the wireless tag reading device 1 can read even a wireless tag that is difficult to read. Figure 6 ) is held by the holding portion 30 as an example, but the second antenna 22, the third antenna 23 or the fourth antenna 24 may also be held by the holding portion 30 in a detachable manner. Furthermore, the plurality of antennas 20 may also be held by the holding portion 30 in a detachable manner.

[0069] In addition, in this embodiment, radio waves for reading wireless tags are radiated from the antenna 20 into the tunnel 10 at the time of initial reading. In other embodiments, radio waves may be radiated from the second antenna, the third antenna, and the fourth antenna other than the first antenna 21 detachably held in the antenna 20 at the time of initial reading. The first antenna 21 radiates radio waves when it is removed from the holding portion 30 and used. By doing so, the power consumed by the first antenna can be saved.

[0070] Figure 6 It is a front cross-sectional view showing an example of the appearance of the holding portion 30 according to the present embodiment. Figure 71 is a side sectional view showing an example of the appearance of the holding portion 30 involved in this embodiment. The holding portion 30 includes a connecting portion 31, a hinge 32, and a mounting portion 33. The connecting portion 31 is a component that connects the holding portion 30 and the first side surface 11. The hinge 32 connects the connecting portion 31 and the mounting portion 33. Moreover, the hinge 32 holds the mounting portion 33 at an arbitrary angle. Therefore, the holding portion 30 can direct the first antenna 21 to any direction.

[0071] The first antenna 21 is mounted on the mounting portion 33. Figure 6 As shown in FIG. 1 , the mounting portion 33 has a U-shaped shape when viewed from the side. In this way, the operator can easily mount the first antenna 21 on the holding portion 30 by sliding the first antenna 21 from above. Figure 7 As shown, the mounting portion 33 has an L-shaped shape when viewed from the front, which supports the lower portions of both sides of the first antenna 21. That is, when the first antenna is mounted on the mounting portion 33, the substantially center of the first antenna 21 is left empty. Therefore, the mounting portion 33 is shaped so as not to hinder the radiation of radio waves by the first antenna 21.

[0072] In addition, if Figure 6 As shown, the first antenna 21 has a grip 201. The operator grips the grip 201 to remove the first antenna 21 from the holder 30, or grips the grip 201 to align the first antenna 21 with the wireless tag.

[0073] Therefore, the grip 201 can improve the operability of the antenna.

[0074] Next, the hardware configuration of the wireless tag reading device 1 will be described. Figure 8 1 is a block diagram showing an example of the hardware configuration of the wireless tag reader 1 according to the present embodiment. The wireless tag reader 1 includes a control unit 101, a storage unit 102, a communication interface 103, an operation unit 104, a display unit 105, a mounting and dismounting detection unit 106, an opening and closing drive unit 107, a first antenna 21, a second antenna 22, a third antenna 23, and a fourth antenna 24.

[0075] The control unit 101 is a computer that controls the overall operation of the wireless tag reading device 1 and realizes various functions of the wireless tag reading device 1. The control unit 101 has a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The CPU controls the operation of the wireless tag reading device 1 in an overall manner. The ROM is a storage medium that stores various programs and data. The RAM is a storage medium that temporarily stores various programs and various data. Moreover, the CPU uses the RAM as a work area (operating area) to execute programs stored in the ROM or the storage unit 102.

[0076] The storage unit 102 is a storage device such as a HDD (Hard Disk Drive) or a SSD (Solid State Drive). The storage unit 102 stores a control program 108. The control program 108 is an operating system and a program for making the functions of the wireless tag reader 1 function. The control program 108 includes a program for making the characteristic functions involved in this embodiment function.

[0077] The communication interface 103 is an interface for communicating with other devices via a network. For example, the communication interface 103 is an interface for communicating with a server storing information related to storage and shipment.

[0078] The operation unit 104 is an input device such as a keyboard for receiving various operations.

[0079] The display unit 105 is, for example, a liquid crystal display device.

[0080] The loading and unloading detection unit 106 (detection unit) detects that the first antenna 21 has been removed from the holding unit 30. In this way, the state of the first antenna 21 can be grasped. The loading and unloading detection unit 106 can be a mechanical switch, a photon sensor, an infrared sensor, or a magnetic sensor. When the first antenna 21 has been removed from the holding unit 30, the loading and unloading detection unit 106 notifies the control unit 101 through GPIO (General Purpose Input Output).

[0081] The first antenna 21 , the second antenna 22 , the third antenna 23 , and the fourth antenna 24 are connected to the control unit 101 through coaxial cables, respectively.

[0082] The opening and closing driving unit 107 is a driving device such as a motor that opens and closes the blocking unit 14 .

[0083] Next, the characteristic functions of the wireless tag reading device 1 are described. Fig. 9 This is a block diagram showing an example of a characteristic functional configuration of the wireless tag reading device 1 according to the present embodiment.

[0084] The control unit 101 of the wireless tag reading device 1 expands the control program 108 of the storage unit 102 in the RAM and operates according to the control program 108, thereby Fig. 9 The functional units shown are created in the RAM. Specifically, the control unit 101 of the wireless tag reader 1 includes a read target setting unit 1001, a notification control unit 1002, an opening and closing control unit 1003, and a reading control unit 1004 as functional units.

[0085] The read object setting unit 1001 sets the object to be read by the wireless tag reader 1. That is, the read object setting unit 1001 sets the predetermined article information to be read from the wireless tag by the wireless tag reader 1. The read object may be the target article, the number of target articles, or other information.

[0086] When the object information set by the read object setting unit 1001 cannot be read from the wireless tag, the notification control unit 1002 notifies that the reading of the wireless tag has failed. For example, when the object information set by the read object setting unit 1001 cannot be read from the wireless tag within a predetermined period, the notification control unit 1002 displays that the reading of the wireless tag has failed on the display unit 105. In addition, the notification control unit 1002 is not limited to displaying on the display unit 105, and can also notify by voice or by other methods.

[0087] The opening and closing control unit 10003 controls the opening and closing drive unit 107 to open and close the blocking unit 14. When the loading and unloading detection unit 106 detects that the first antenna 21 has been removed from the holding unit 30, the opening and closing control unit 1003 controls the opening and closing drive unit 107 to close the entrance and exit of the tunnel 10 through the blocking unit 14. In other words, the blocking unit 14 closes the entrance and exit of the tunnel 10 when the loading and unloading detection unit 106 detects that the antenna 20 has been removed.

[0088] The reading control unit 1004 causes the plurality of antennas 20 to emit radio waves. In this way, the reading control unit 1004 reads wireless tags passing through the interior of the tunnel 10. When the first antenna 21 is not removed from the holding unit 30, the reading control unit 1004 causes the antennas 20 to emit radio waves in sequence in a time-sharing manner. In this way, the reading control unit 1004 reads wireless tags.

[0089] When the attachment and detachment detection unit 106 detects that the first antenna 21 has been detached from the holding unit 30, the reading control unit 1004 causes the detached first antenna 21 to emit radio waves. Here, when the first antenna 21 has been detached from the holding unit 30, the operator aligns the first antenna 21 with the wireless tag to read the wireless tag. Therefore, it is not necessary to radiate radio waves from the second antenna 22, the third antenna 23, and the fourth antenna 24. Therefore, when the first antenna 21 has been detached from the holding unit 30, the reading control unit 1004 causes the radio waves to be radiated from the first antenna 21 among the first antenna 21, the second antenna 22, the third antenna 23, and the fourth antenna 24.

[0090] Furthermore, when the operator points the first antenna 21 at the wireless tag, the wireless tag reader 1 may mistakenly read a wireless tag outside the wireless tag reader 1. Therefore, when the blocking unit 14 closes the entrance of the tunnel 10, the reading control unit 1004 causes the removed first antenna 21 to radiate radio waves.

[0091] Furthermore, when the entrance and exit of the wireless tag reader 1 are closed by the blocking unit 14, the wireless tag reader 1 does not read the wireless tag located outside the wireless tag reader 1. Therefore, when the blocking unit 14 closes the entrance and exit of the tunnel 10, the reading control unit 1004 increases the output of the radio wave radiated by the first antenna 21. In this way, the reading control unit 1004 improves the accuracy of reading the wireless tag.

[0092] As described above, the wireless tag reading device 1 involved in this embodiment has a tunnel 10 into which a flatbed truck carrying articles with wireless tags attached enters. A plurality of antennas 20 provided inside the tunnel 10 radiate radio waves for reading wireless tags into the tunnel 10. The antennas 20 are detachably held by the holding portion 30. That is, when the wireless tag reading device 1 fails to read a wireless tag, the operator can remove the antenna 20 from the holding portion 30 and aim the antenna 20 at the wireless tag that failed to be read. Therefore, the wireless tag reading device 1 can easily read wireless tags that are difficult to read.

[0093] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments may be implemented in various other forms, and various omissions, substitutions, and changes may be made without departing from the gist of the invention. These embodiments and their variations are all included in the scope or gist of the invention, and are also included in the invention described in the scope of the claims and their equivalents.

[0094] The programs executed in the devices of the above-mentioned embodiments and modifications are provided by being pre-installed in the storage medium (ROM or storage unit) possessed by each device, but are not limited to this. For example, the programs may be provided by recording in a computer-readable storage medium such as a CD-ROM, a floppy disk (FD), a CD-R, or a DVD (Digital Versatile Disk) in an installable or executable form. Furthermore, the storage medium is not limited to a medium independent of a computer or an embedded system, but also includes a storage medium that stores or temporarily stores a program after downloading it via a LAN, the Internet, or the like.

[0095] Furthermore, the program executed by each device of the above-described embodiment and modified examples may be stored in a computer connected to a network such as the Internet and provided by downloading via the network, or may be provided or deployed via a network such as the Internet.

Claims

1. A wireless tag reading device, characterized in that: include: tunnel; A plurality of antennas, each of the plurality of antennas radiating radio waves for reading wireless tags into the tunnel; A reading control unit causes the plurality of antennas to radiate the radio waves; as well as a holding unit that can detachably hold any one of the plurality of antennas; Among them, it also includes: a detection unit that detects that the antenna has been removed from the holding unit, The reading control unit causes the detached antenna to radiate the radio wave when the detection unit detects that the antenna has been detached from the holding unit.

2. The wireless tag reading device according to claim 1, wherein: The reading control unit prevents the antenna from radiating radio waves when the detection unit does not detect that the antenna has been detached from the holding unit.

3. The wireless tag reading device according to claim 1, wherein: The reading control unit does not cause the other antennas to emit the radio waves when causing the removed antenna to emit the radio waves.

4. The wireless tag reading device according to claim 1, wherein: The holding portion has a shape that allows the detachable antenna to be mounted by sliding it from above.

5. The wireless tag reading device according to claim 1, wherein: The holding portion includes a connecting portion connected to the tunnel, a mounting portion on which the detachable antenna is mounted, and a hinge connecting the connecting portion and the mounting portion, wherein the hinge holds the mounting portion at an arbitrary angle.

6. The wireless tag reading device according to claim 1, wherein: The detachable antenna has a handle.

7. The wireless tag reading device according to claim 1, wherein: Also includes: The blocking portion is formed of a radio wave shielding material that shields the radio wave radiated by the antenna. Wherein, when the detection unit detects that the antenna has been removed, the blocking unit closes the entrance and exit of the tunnel.

8. The wireless tag reading device according to claim 7, wherein: The reading control unit causes the removed antenna to radiate the radio wave when the blocking unit closes the entrance.

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