JP5080937B2 - Reader / writer and gate system - Google Patents

Description

  The present invention relates to a reader / writer (mobile identification device) that performs data communication with a mobile information communication body such as a wireless tag and a gate system including the reader / writer.

  A reader / writer that performs data communication with a wireless tag and a wireless tag system including the reader / writer are used in various fields and in various forms. In particular, in logistics management and product manufacturing processes, wireless tags are affixed to articles and products that are transported on a belt conveyor, and the antenna attached to the belt conveyor or the gate attached to the belt conveyor is used. The article / product is managed by writing data to the wireless tag or reading data from the wireless tag (see, for example, FIG. 2 of Patent Document 1).

  In this type of system, in order to detect that an article / product transferred on the belt conveyor has reached the vicinity of the antenna, an optical sensor disposed in the vicinity of the antenna and a controller for controlling the optical sensor (PC in Patent Document 1). ) Etc. are further needed.

JP 2006-297172 A

  The present invention detects that an article / product conveyed on the transfer path has reached the vicinity of the antenna without separately providing a sensor such as an optical sensor and a controller required for the system of Patent Document 1. An object of the present invention is to provide a system that can perform the above and a reader / writer suitable for the system.

  According to the present invention, as a first reader / writer, a reader / writer that performs data communication with a mobile information communication body, the first antenna port connected to the first antenna, and the second connected to the second antenna. An antenna port, a detection circuit connected to the second antenna port, and a control circuit connected to the detection circuit, wherein the second antenna connected to the second antenna port is output from the first antenna. A reader / writer with a control circuit used to monitor the power level is obtained.

  Further, according to the present invention, as the second reader / writer, in the first reader / writer: a preliminary detection circuit connected to the first antenna port and connected to the control circuit, and connected to the control circuit And a switch circuit provided between the detection circuit and the preliminary detection circuit and the transmission / reception unit; the control circuit switches the switch circuit to switch the first antenna or The second antenna is used to monitor the power level output from the second antenna or the first antenna; a reader / writer is obtained.

  According to the present invention, as the third reader / writer, in the second reader / writer, a reader / writer in which the switch circuit includes a transfer switch can be obtained.

  Furthermore, according to the present invention, as the fourth reader / writer, in the second reader / writer, a reader / writer in which the switch circuit includes a simple selection switch can be obtained.

  According to the present invention, any one of the first to fourth reader / writers, the first antenna, the second antenna, the first antenna, and the second antenna are attached as the first gate system. A gate system comprising: a gate system, wherein the control circuit determines whether an article has reached the gate based on the monitored power level.

  According to the present invention, as the second gate system, in the first gate system, the control circuit performs data communication with the mobile information communication body when it is determined that the article has reached the gate. Therefore, a gate system can be obtained that controls to increase the power level output from the first antenna or the second antenna.

  Further, according to the present invention, as the third gate system, any one of the first to fourth reader / writers, the first antenna, and the second antenna provided so as to sandwich the article transfer path with the first antenna. And a gate system comprising: an antenna, wherein the control circuit determines whether the first circuit and the second antenna are reached based on the monitored power level. It is done.

  Further, according to the present invention, as the fifth reader / writer, in the second reader / writer, one or more additional antenna ports respectively connected to one or more additional antennas, and each of the additional antenna ports One or more additional detection circuits connected, further comprising an additional detection circuit connected to the control circuit; the switch circuit is also connected to the additional detection circuit; Selects one of the first antenna, the second antenna, and the additional antenna as an output antenna by switching the switch circuit, while the first antenna, the second antenna, and the additional antenna are selected. At least one other of the antennas is used to monitor the power level output from the output antenna; a reader / writer is obtained That.

  According to the present invention, as a fourth gate system, a fifth reader / writer, the first antenna, the second antenna, the additional antenna, the first antenna, the second antenna, and A gate system with a gate to which the additional antenna is attached, wherein the control circuit determines, based on the monitored power level, whether an article has reached the gate. It is done.

  Further, according to the present invention, as the fifth gate system, in the fourth gate system, the control circuit performs data communication with the mobile information communication body when it is determined that the article has reached the gate. Therefore, a gate system can be obtained that controls to increase the power level output from the first antenna, the second antenna, or the additional antenna.

  When an article conveyed on the transfer path reaches the vicinity of an antenna while the level of power output from one antenna is monitored by another antenna, the monitored power level changes. . Since the reader / writer according to the present invention detects the arrival of an article with this power level change, it is possible to eliminate the need for a sensor such as an optical sensor and a controller for controlling the sensor as in Patent Document 1.

  Hereinafter, a reader / writer according to an embodiment of the present invention and a gate system including the reader / writer will be described in detail with reference to the drawings.

(First embodiment)
As shown in FIG. 1, the gate system according to the first embodiment of the present invention straddles the reader / writer 100, the two antennas 201 and 202 connected to the reader / writer 100, and the belt conveyor 300. And a grounded gate 400. The antennas 201 and 202 are attached to the gate 400 so as to face each other across the transfer path of the article 600 to which the wireless tag 500 is affixed (that is, the belt conveyor 300 in this embodiment).

  As shown in FIG. 2, the reader / writer 100 according to the present embodiment includes an antenna port 111 connected to an antenna 201, an antenna port 112 connected to an antenna 202, a detection circuit 121 connected to the antenna port 111, and an antenna. Detection circuit 122 connected to port 112, transfer switch 130, circulator 140 connected to transfer switch 130, transmission circuit 150 and reception circuit 160 connected to circulator 140, synthesizer connected to transmission circuit 150 and reception circuit 160 170 and a control circuit 180 are provided. The control circuit 180 is connected to the detection circuits 121 and 122, the transmission circuit 150, the reception circuit 160, and the synthesizer 170, and controls the transfer switch 130. The transmission circuit 150 receives transmission data from the control circuit 180, generates a transmission signal using the carrier frequency generated by the synthesizer 170, and outputs the transmission signal to the transfer switch 130 via the circulator 140. Receives the received signal via the circulator 140, demodulates the received signal using the carrier frequency generated by the synthesizer 170, and outputs it to the control circuit 180 as received data. That is, the circulator 140, the transmission circuit 150, the reception circuit 160, and the synthesizer 170 in this embodiment function as a transmission / reception unit connected between the transfer switch 130 and the control circuit 180.

  The transfer switch 130 in the present embodiment connects either the detection circuit 121 or the detection circuit 122 to the circulator and connects the other detection circuit 121 or 122 to the ground via a resistor.

  The detection circuits 121 and 122 in the present embodiment are configured to function only when connected to the ground via a resistor. That is, when connected to the circulator 140 via the transfer switch 130, the reception signal received via the antenna 201 or 202 is transmitted to the reception circuit 160, and the transmission signal output from the transmission circuit 150 is transmitted from the antenna 201 or 202. To be sent.

  For example, when a radio wave is transmitted from the antenna 201, if there is no article between the antenna 201 and the antenna 202, the signal transmitted from the antenna 201 is attenuated according to the distance between the antenna 201 and the antenna 202. However, it is received by the antenna 202 at that level. The received power level in this case is hereinafter referred to as “normal power level”. On the other hand, when there is an article between the antenna 201 and the antenna 202, the radio wave transmitted from the antenna 201 is blocked by the article and does not reach the antenna 202 or is reflected by the article to be attenuated more than necessary. In this state, the antenna 202 is reached. That is, the power level received by the antenna 202 is lower than the normal power level. Therefore, the control circuit 180 knows whether or not an article exists between the antenna 201 and the antenna 202 by monitoring the power level of the radio wave received by the antenna 202 and comparing it with the normal power level. Can do.

  The normal power level is obtained by, for example, receiving a radio wave transmitted from the antenna 201 at the antenna 202 and detecting the received radio wave by the detection circuit 122 in a state where there is no article after installing the reader / writer according to the present embodiment. By acquiring and storing it in a memory in the control circuit, it may be used for comparison with the received power level as described above. However, the present invention is not limited to this, and for example, there is an article between the antenna 201 and the antenna 202 depending on the magnitude of fluctuation in the detection level when the gate system including the reader / writer according to the present invention is operated. It may be determined whether or not.

  When it is determined that there is an article between the antenna 201 and the antenna 202, that is, the article has reached the vicinity of the antenna on the transfer path (belt conveyor 300), the control circuit 180 first passes the antenna 201 through the antenna 201. Then, data communication with the wireless tag 500 attached to the article 600 is attempted. Here, when the wireless tag 500 is attached to the side surface of the article 600 on the antenna 201 side, data communication can be performed between the control circuit 180 and the wireless tag 500. On the other hand, when the wireless tag 500 is affixed to the side surface of the article 600 on the antenna 202 side, the control circuit 180 may obtain a response from the wireless tag 500 even when trying to communicate with the wireless tag 500 via the antenna 201. Can not. In that case, the control circuit 180 switches the transfer switch 130 and tries to perform data communication with the wireless tag 500 via the antenna 202, thereby obtaining a response from the wireless tag 500. As described above, in the present embodiment, since the antennas 201 and 202 are switched by the transfer switch 130, it is possible to cope with a case where the surface of the article 600 to which the wireless tag 500 is attached is different.

  In the gate system according to the above-described embodiment, the gate 400 is installed so as to straddle the belt conveyor 300, and the antennas 201 and 202 are attached to the gate 400. As shown in FIG. 2, the antennas 201 and 202 may be directly attached to the transfer path such as the belt conveyor 300 or attached by using other means, and the gates may be configured by the antennas 201 and 202. .

(Second Embodiment)
The gate system according to the second embodiment of the present invention has the same configuration as the gate system according to the first embodiment described above except that it includes a reader / writer 100a as shown in FIG. . As can be understood from a comparison between FIG. 2 and FIG. 3, the reader / writer 100a according to the present embodiment is different from the transfer switch 130 in the reader / writer 100 (FIG. 2) according to the first embodiment described above. It is replaced by a circuit. Therefore, in FIG.2 and FIG.3, the same referential mark is attached | subjected about the same component, and suppose that description about them is abbreviate | omitted.

  The switch circuit of the reader / writer 100a according to the present embodiment uses SPDT (Single Pole Double Throw) switches 133, 135, and 137, which are simple selection switches. Specifically, the SPDT switch 133 switches whether the circulator 140 is connected to the SPDT switch 135 or the SPDT switch 137. The SPDT switch 135 switches whether the detection circuit 121 is connected to the SPDT switch 133 or connected to the ground via a resistor. Similarly, the SPDT switch 137 switches whether the detection circuit 122 is connected to the SPDT switch 133 or connected to the ground via a resistor. The SPDT switches 133, 135, and 137 are controlled by the control circuit 180. The control circuit 180 according to the present embodiment also receives radio waves transmitted from either one of the antennas 201 and 202 by appropriately switching the SPDT switches 133, 135, and 137, and receives the reception. By monitoring the power level, it is possible to detect the arrival of an article conveyed on the transfer path near the antenna without using an optical sensor or the like, and then use one of the antennas 201 and 202 to Data communication can be performed.

  In the above-described embodiment, for example, the SPDT switch 133 is replaced with a switch having three or more selection ports, such as a SP3T (Single Pole 3 Throw) switch or a SP4T (Single Pole 4 Throw) switch, and accordingly, A system having three or more antennas may be constructed by adding a detection circuit, an antenna port, and an antenna. Even in the case of a system having three or more antennas, the principle of operation is the same as in the first and second embodiments described above, and radio waves output from any one of the antennas are different. It is possible to detect whether or not an article has arrived between these antennas by receiving the signals at the antennas and monitoring their power levels. Furthermore, in the case of a system having three or more antennas, after detecting the arrival of the article, by trying to communicate with the wireless tag while switching the antenna appropriately, for example, the wireless tag is attached to the upper surface in addition to the side of the article. Even if it is a case, the response from a wireless tag can be obtained by either antenna.

  As mentioned above, although the gate system by embodiment of this invention was concretely demonstrated using drawing, this invention is not limited to these. For example, the reader / writers 100 and 100a according to the above-described embodiments are each provided with the switch circuit, but the switch circuit may be omitted and the roles of the antennas 201 and 202 may be fixed. For example, in the reader / writer 100b shown in FIG. 4, the antenna 201 is connected to the circulator 140 via the antenna port 111, and is used for radio wave output until the arrival of an article near the antenna on the transfer path is detected. And is used for data communication with the wireless tag after the arrival of the article is detected. On the other hand, the antenna 202 is used for receiving the radio wave output from the antenna 201 and monitoring the received power level.

  Further, in the above-described embodiment, the power of the radio wave output from the antenna is different between the case where the arrival of the article near the antenna on the transfer route is detected and the case where data communication with the wireless tag is performed. It is good. Specifically, lower power may be output from the antenna for the purpose of detecting the arrival of the article, and higher power may be output from the antenna for the purpose of data communication with the wireless tag. . With this configuration, it is possible to reduce the power consumption required for detecting the arrival of an article, and to minimize mutual interference when a plurality of reader / writers are used.

It is a figure which shows the gate system by the 1st Embodiment of this invention. It is a figure which shows the reader / writer contained in the gate system of FIG. It is a figure which shows the reader / writer by the 2nd Embodiment of this invention. It is a figure which shows the modification of the reader / writer of this invention.

Explanation of symbols

100, 100a, 100b Reader / writer 111, 112 Antenna port 121, 122 Detection circuit 130 Transfer switch 133, 135, 137 SPDT switch 140 Circulator 150 Transmission circuit 160 Reception circuit 170 Synthesizer 180 Control circuit 201, 202 Antenna 300 Belt conveyor 400 Gate 500 Wireless tag 600 article

Claims (11)

A reader / writer that performs data communication with a mobile information communication body attached to an article ,
A first antenna port connected to the first antenna;
A first detection circuit connected to the first antenna port;
A second antenna port connected to the second antenna;
A second detection circuit connected to the second antenna port;
A switch circuit connected to the first detection circuit and the second detection circuit;
A transmission / reception unit connected to the switch circuit;
A control circuit which is connected to the first detection circuit, the second detection circuit, and the transmission / reception unit and which controls switching of the switch circuit;
With
The control circuit controls the switch circuit to change the power level output from the first antenna when the transmission / reception unit and the first detection circuit are connected to each other with the second antenna and the second detection circuit. When the transmission / reception unit and the second detection circuit are connected by controlling the switch circuit, the power level output from the second antenna is changed between the first antenna and the first detection circuit. To monitor via a reader / writer. The reader / writer according to claim 1 , wherein the switch circuit includes a transfer switch. The reader / writer according to claim 1 , wherein the switch circuit includes a simple selection switch. One or more additional antenna ports each connected to one or more additional antennas and one or more additional detection circuits connected to each of the additional antenna ports, the additional circuit connected to the control circuit A detection circuit,
The switch circuit is also connected to the additional detection circuit,
The control circuit controls the switch circuit to select any one of the first antenna, the second antenna, and the additional antenna as an output antenna to connect to the transmission / reception unit, while the first antenna Monitoring a power level output from the output antenna via at least one of the second antenna and the additional antenna
The reader / writer according to claim 1 . 5. The reader / writer according to claim 4 , comprising: the first antenna; the second antenna; the additional antenna; and a gate to which the first antenna, the second antenna, and the additional antenna are attached. A gate system, wherein the control circuit determines whether an article has reached the gate based on the monitored power level. When the control circuit determines that the article has reached the gate, the control circuit performs data communication with the mobile information communication body attached to the article, so that the first antenna, the second antenna, or the additional antenna is provided. The gate system according to claim 5 , wherein the transmission / reception unit is controlled to increase a power level output from an antenna. A reader writer according to any one of claims 1 to 3, said first antenna, said second antenna, in the first antenna and gate system including a gate to which the second antenna is attached A gate system, wherein the control circuit determines whether an article has reached the gate based on the monitored power level. When the control circuit determines that the article has reached the gate, the control circuit outputs data from the first antenna or the second antenna in order to perform data communication with the mobile information communication body attached to the article. The gate system according to claim 7 , wherein the transmitting / receiving unit is controlled to increase a power level. The reader / writer according to any one of claims 1 to 3 , the first antenna, and the second antenna provided so as to sandwich a transfer path of an article attached with a mobile information communication body with the first antenna. A gate system comprising: a gate system, wherein the control circuit determines whether the article has reached between the first antenna and the second antenna based on the monitored power level. A gate system comprising a reader / writer that performs data communication with a mobile information communication body attached to an article, a first antenna, a second antenna, and a gate to which the first antenna and the second antenna are attached. And
  The reader / writer is
  A first antenna port connected to the first antenna;
  A transmitting / receiving unit connected to the first antenna port and outputting power from the first antenna via the first antenna port;
  A second antenna port connected to the second antenna;
  A detection circuit connected to the second antenna port;
  A control circuit connected to the transmission / reception unit and the detection circuit, wherein the control circuit monitors a power level output from the first antenna via the second antenna, the second antenna port, and the detection circuit; With
  The control circuit determines whether or not the article has reached the gate based on the monitored power level, and if it is determined that the article has reached the gate, movement information attached to the article In order to perform data communication with a communication body, the transmission / reception unit is controlled to increase the power level output from the first antenna.
Gate system. The gate system according to claim 10, wherein
The first antenna and the second antenna are provided so as to sandwich a transfer path of an article attached with a mobile information communication body,
The control circuit determines whether or not the article has reached between the first antenna and the second antenna.

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