JP2007142687A - Transmission intermediate medium in radio communication system of electromagnetic induction system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To establish communication with a non-contact tag at a place distant from an antenna of an interrogator and to flexibly control the communication in the communication using an electromagnetic induction system. <P>SOLUTION: An RF tag system is provided which is composed of a non-contact tag, an interrogator and an intermediate medium for mediating between both the communications. The intermediate medium has an extending section being a conductor extending from the antenna of the interrogator and having no feeding point. It also has a pickup section arranged near the antenna of the interrogator and picking up a signal generated from the antenna of the interrogator; and a communication section for regenerating a magnetic field for performing communication based on electromagnetic induction with the non-contact tag. Further, the intermediate medium has an end processing section for controlling the propriety of communication with the non-contact tag in the communication section. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an RF (Radio Frequency) tag system.

  In recent years, the use of RFID (Radio Frequency Identification) has become active as a means for realizing a ubiquitous society. The RFID exchanges information by performing wireless communication between a reader / writer serving as an interrogator and a non-contact tag serving as a responder. One of the methods for exchanging the interrogator and the responder in this way is a communication method using electromagnetic induction.

  The electromagnetic induction method utilizes the fact that when a non-contact tag is inserted into the induction magnetic field generated by flowing a high-frequency current through the interrogator loop antenna, current flows through the loop antenna of the non-contact tag due to electromagnetic induction. The electronic circuit of the tag is operated. In the communication system using this electromagnetic induction system, it is necessary to put a non-contact tag in the induction field of the interrogator in order to perform communication. For this reason, in order to realize communication by the electromagnetic induction method, for example, it is necessary to hold a non-contact tag in close proximity to the antenna of the interrogator so as to be horizontal with the antenna surface. FIG. 17 is a diagram illustrating an example of conventional communication. In FIG. 17, the non-contact tag A within the induction magnetic field from the interrogator C can communicate with the interrogator C, but the non-contact tag B outside the magnetic field communicates with the interrogator C. Could not do. For this reason, when the interrogator is fixedly installed, it is necessary to install the interrogator again at a position suitable for communication, or a separate interrogator is installed because the communication distance does not reach. Or other problems have occurred.

Patent Document 1 discloses an invention in which a data repeater is provided between an interrogator and a non-contact tag for the purpose of solving a communication distance which is a problem when such an electromagnetic induction method is used. Has been.
JP 2005-176082 A

  However, the invention of Patent Document 1 merely realizes an increase in communication distance. For this reason, in an area where the communication distance is extended, there is a problem that communication is forcibly performed even when communication is not desired.

  Therefore, the present invention has been made in view of such problems, and in communication using an electromagnetic induction method, it is possible to realize communication with a non-contact tag in a place away from an interrogator antenna, and to flexibly communicate. It is an object of the present invention to provide an RF tag system which can be controlled.

  Therefore, in order to solve such a problem, the present invention provides an RF tag system including a non-contact tag, an interrogator, and an intermediate medium that mediates communication between the two. The intermediate medium has an extension that is a conductor having no feeding point, which is extended from the interrogator antenna, and is arranged in the vicinity of the interrogator antenna to generate a signal generated from the interrogator antenna. A pickup unit for picking up and a communication unit for reproducing a magnetic field to perform electromagnetic induction communication with the non-contact tag are included. Further, the intermediate medium may include an end processing unit for controlling whether or not communication with the non-contact tag in the communication unit is possible.

  In the present invention, by providing the intermediate medium, it is possible to communicate with the non-contact tag via the intermediate medium even in the place other than the sky or the vicinity of the interrogator antenna. Further, by performing end processing, it is possible to control the availability of communication, so usability can be improved.

  Hereinafter, embodiments of each invention will be described. Note that the present invention is not limited to these embodiments, and can be implemented in various modes without departing from the spirit of the present invention.

  In addition, the relationship between the following embodiment and a claim is as follows. The first embodiment will mainly describe claims 1, 2, 3, 4, 5, 6, 7, 8, 9 and the like. The second embodiment will mainly describe claims 10, 11, 12, 13, 14, 15, 16 and the like. The third embodiment will mainly describe claims 17 and 18. The fourth embodiment will mainly describe claims 19, 20, 21, 22 and the like. The fifth embodiment will mainly describe Claim 23.

<< Embodiment 1 >>
<Outline of Embodiment 1>
The present embodiment relates to an RF tag system including a contactless tag, an interrogator, and an intermediate medium that mediates communication between the two. FIG. 1 is a diagram illustrating an example of a concept in the present embodiment. FIG. 1 shows a configuration having an intermediate medium D in addition to FIG. As shown in FIG. 1, the contactless tag A in the communication area of the interrogator C and the interrogator C can communicate with each other, and further the communication of the interrogator C by using the intermediate medium D. It is also possible to communicate with the non-contact tag B outside the area.

<Configuration of Embodiment 1>
The RF tag system in this embodiment includes a non-contact tag, an interrogator, and an intermediate medium.

  First, the “non-contact tag” will be described. The non-contact tag mainly includes a control microprocessor and an antenna, and is used for fee payment, entry / exit, inventory management, and the like. FIG. 2 shows an example of a block diagram of the non-contact tag. The operation of the non-contact tag (200) that has entered the magnetic field of the interrogator will be briefly described. First, electric power is obtained by electromagnetic induction at the antenna (201), and this is converted into electromotive force by the power regeneration circuit (202). A signal component is extracted from the electromagnetic wave by the band pass filter (203), the modulated signal is demodulated by the demodulator (204), and the demodulated command is interpreted by the control microprocessor (205). The control microprocessor (205) exchanges information with the ROM and RAM (206) based on the input command. When a signal is returned to the interrogator, the control microprocessor (205) sends a signal carrying information to the modulator (207), and the signal modulated by the modulator (207) is transmitted to the antenna. (201) to the interrogator. This description is only for an example of a non-contact tag. For example, a non-contact tag not equipped with a control microprocessor or an active non-contact tag equipped with a battery is also used in this embodiment. Included in the non-contact tag shown.

  Next, the “interrogator” will be described. The interrogator of this embodiment communicates with the non-contact tag (200) mainly using a frequency of 13.56 MHz in a short wave band. FIG. 3 shows an example of a block diagram of the interrogator. The operation of the interrogator will be briefly described with reference to FIG. The control processor (304) of the interrogator (300) sends a command stored in the ROM or RAM (305) to the modulator (308) as a carrier wave, and the modulator (308) modulates the carrier wave. Transmit from antenna (301). When the response from the non-contact tag is received by the antenna (301), the signal component is extracted by the band pass filter (302), demodulated by the demodulator (303), and the control processor (304). ) To send the response. The control processor (304) exchanges information with a host computer (not shown) through the interface circuit (306) as necessary. Note that this description is about an example of an interrogator and is not limited to the interrogator shown in FIG. Of course, communication using other frequencies is also possible.

  In this way, communication using electric power by electromagnetic induction is performed between the non-contact tag and the interrogator. The present embodiment is characterized in that an intermediate medium that mediates communication between the non-contact tag and the interrogator is provided.

  Next, the configuration of the “intermediate medium” will be described. FIG. 4 is a diagram illustrating an example of the RF tag system of the present embodiment. In FIG. 4, the portion indicated by the bold line represents the intermediate medium (400). As shown in FIG. 4, the intermediate medium (400) has an “extension portion” (401). The “extension” (401) has a feeding point that is extended from the interrogator antenna so that it can communicate with the non-contact tag via the intermediate medium even in a place other than the sky or the vicinity of the interrogator antenna. There is no conductor. The “conductor having no feeding point” is a conductor that does not have a direct contact with the feeding line of the interrogator or the antenna, and is clearly distinguished from the extended portion of the antenna. This is because it is not necessary to have a feeding point because current flows through the intermediate medium due to electromagnetic induction. Examples of the conductor constituting the extension include a power supply cable and a communication cable. Further, since the extension is mainly used as a transmission line, conductors such as a waveguide, a coaxial line, a strip line, a microstrip line, a coplanar line, and a parallel line can also constitute the extension. Note that all of the intermediate medium itself may be configured by the conductor.

  Further, as shown in FIG. 4, the intermediate medium (400) includes a pickup unit (402) and a communication unit (403).

  The “pickup unit” (402) is arranged near the antenna (301) of the interrogator (300) and picks up a signal generated from the antenna (301) of the interrogator (300). “Near the interrogator antenna” means within the range of the magnetic field of the interrogator. As with the extension, the pickup (402) does not have a physical contact with the interrogator antenna (301). “Picking up a signal” means conducting an electromagnetic coupling by an induced magnetic field generated by an antenna of an interrogator and conducting a high-frequency current containing a signal component to an intermediate medium. The pickup unit (402) may have any shape as long as a signal can be picked up. Moreover, the conductor integrated with the extension part (401) already demonstrated may be sufficient.

  FIG. 5 is a diagram schematically showing an example of the pickup unit (402). As shown in FIG. 5, the pickup unit may have first conductor means (501) along a part of the conductor of the antenna of the interrogator. The first conductor means (501) constitutes a pickup section, and specifically, various conductors such as a power supply cable and a communication cable can be used in the same manner as the extension section. Since the first conductor means (501) is along a part of the conductor of the antenna of the interrogator, the signal can be picked up even when the space for installing the intermediate medium is limited. it can. On the other hand, FIG. 6 is a diagram schematically showing another example of the pickup unit (402). As shown in FIG. 6, the pickup unit may have a loop-shaped second conductor means (601) disposed in the vicinity of the antenna of the interrogator. Unlike the first conductor means (501), the second conductor means (601) is characterized by a loop shape. The “loop shape” includes a case where a conductor itself such as a cable has a loop shape as shown in FIG. 6, for example, and a case where the second conductor means has a coil shape. Thus, the second conductor means (601) having a loop shape can obtain more electromotive force due to electromagnetic induction. In addition, since the pick-up part shows the part arrange | positioned in the vicinity of an antenna, as shown in FIG.5 and FIG.6, it may be arrange | positioned outside the antenna (301), and shows in FIG. Thus, it may be arranged inside the antenna (301) loop.

  The “communication unit” (403) reproduces the magnetic field in order to perform electromagnetic induction communication with the non-contact tag (404). This “communication” indicates that communication is performed between the contactless tag (404) and the interrogator (300). “Electromagnetic induction communication” refers to communication using electric power by electromagnetic induction. As a method of “reproducing the magnetic field”, it is possible to reproduce the magnetic field by making the conductor of the intermediate medium into a loop shape, but it is not always necessary to make the loop shape. For example, when a high current flows through the intermediate medium, even a portion having a linear shape can be a “communication unit”. FIG. 7 shows an example of the communication unit. As shown in FIGS. 7A and 7B, the communication unit may be configured in a loop shape that does not contact the conductor. The “loop shape” includes both a circular shape and a square shape. Moreover, the communication part may be comprised by the bending of the conductor, as shown in FIG.7 (c). Thus, the magnetic field is regenerated by the high frequency current transmitted through the inductance of the communication unit and the extension unit. This magnetic field enables communication with the non-contact tag. That is, when a non-contact tag enters the magnetic field, an electromotive force is generated in the non-contact tag by electromagnetic induction, and the non-contact tag performs processing according to a command read from an electromagnetic wave of a high-frequency current that has flowed through the intermediate medium. The response from the non-contact tag to the interrogator is sent to the antenna of the interrogator via the communication unit, the extension unit, and the pickup unit, contrary to the signal from the interrogator.

  Further, as shown in FIG. 4, the intermediate medium (400) can be provided with a plurality of communication units (403A, 403B). By providing the communication unit at a plurality of locations, the intermediate medium can be used in various situations. In FIG. 4, the communication unit is explicitly shown as a loop, but it is not necessarily clear from the appearance of the communication unit. For example, in FIG. 4, the bold line portion indicates the intermediate medium (400), and the extension unit (401), the pickup unit (402), and the communication unit (403) for each function group constituting each function. For example, all of these can be realized by one conductor constituting the intermediate medium (400). Therefore, it is of course possible that the extension part (401) in FIG. 4 also serves as the communication part (403), or conversely, the communication part (403) also serves as the extension part (401).

  In addition, as shown in FIG. 8, it is possible to extend the communication distance using a plurality of intermediate media. In FIG. 8, the intermediate medium (801) picks up a signal from the interrogator antenna (301), the intermediate medium (802) picks up the signal, and the intermediate medium (802) picks up the signal as intermediate. The medium (803) can pick up. By using an intermediate medium in this way, signals with a phase shift can be sent, so that interference between a non-contact tag using a normal antenna and a non-contact tag using an intermediate medium can be prevented. . As described above, since an effect obtained by the intermediate medium is simply different from that obtained by simply extending the antenna of the interrogator, both are clearly distinguished.

  In addition, the intermediate medium in this embodiment should just be a thing as long as it transmits the signal of the carrier frequency for communication. That is, the example described above is described by taking a passive non-contact tag without a battery as an example, but for example, when an active non-contact tag with a battery is used, This is because an electromotive force due to electromagnetic induction is not always necessary for the operation of the contactless tag, and the intermediate medium can achieve its purpose only by transmitting a signal of a carrier frequency for communication.

<Effect of Embodiment 1>
In the RF tag system according to the present embodiment, by having an intermediate medium that mediates communication between the contactless tag and the interrogator, it is possible to realize communication with the contactless tag at an arbitrary position. . Such communication can be realized only by placing an intermediate medium in the vicinity of an existing interrogator, so that communication mediation can be easily realized.

<< Embodiment 2 >>
<Outline of Embodiment 2>
The RF tag system according to the present embodiment is characterized in that the intermediate medium described in the first embodiment has a configuration capable of controlling the availability of communication.

<Configuration of Embodiment 2>
As in the first embodiment, the RF tag system in the present embodiment includes a non-contact tag, an interrogator, and an intermediate medium. Since the non-contact tag and the interrogator are the same as those described in the first embodiment, description thereof is omitted here.

  FIG. 9 is a diagram showing an RF tag system in the present embodiment. In addition to the configuration described in the first embodiment, the intermediate medium (900) in the present embodiment has an end processing unit (901). The configuration of the other intermediate medium is the same as that described in the first embodiment.

  The “end processing unit” (901) is for controlling whether or not communication with the non-contact tag in the communication unit is possible. FIG. 10 is a diagram for explaining the end processing unit (1001) in the present embodiment. As shown in FIG. 10, the end processing unit (1001) has impedance changing means (1002) for controlling whether or not communication is possible. “Control whether communication is possible” means, for example, that communication is enabled by performing termination processing at the end of the intermediate medium, and conversely, communication is disabled by not performing termination processing at the end of the intermediate medium. Can be mentioned. Termination is to match impedance at the end. When the impedances at the ends are mismatched, signal reflection occurs accordingly, and as a result, the waveform is distorted and communication cannot be performed. Therefore, it is possible to control the availability of communication at the communication unit by changing the impedance at the end. For example, when a plurality of communication units are provided and no end processing unit is provided, only a communication unit far from the signal source (that is, a communication unit close to the end) cannot communicate. The communication unit can communicate normally. This is because waveform distortion can be absorbed by a communication unit far from the signal source.

  As shown in FIG. 10, the impedance changing means (1002) may have a first switch device (1003) for connecting the extension conductor (1007) and the end (1008). The “extension conductor” is a conductor constituting the intermediate medium, and specifically, a conductor constituting the extension portion. The “end part” is a part in contact with a part to be subjected to termination processing. When the extension conductor is not connected to the end portion by the first switch device (1003), the termination process is not performed, and therefore communication cannot be performed in the communication unit adjacent to the extension conductor.

  Moreover, the impedance changing means may have a second switch device (1004) for connecting the resistance element and the end. Further, in order to achieve other impedance matching, a third switch device (1005) for connecting the coil and the end portion may be provided, and a fourth switch device for connecting the capacitor and the end portion. (1006) may be included. In addition, in FIG. 10, the example in which all the 1st switch device (1003), the 2nd switch device (1004), the 3rd switch device (1005), and the 4th switch device (1006) were included in the impedance change means was described. However, the present invention is not limited to this. For example, it is of course possible that the impedance changing means is configured from any one or more of the first switch device to the fourth switch device. In addition, when matching impedance, by adjusting the impedance of the resistance element, coil, capacitor, etc. so as to match the characteristic impedance of the intermediate medium and the cable of the extension portion constituting the intermediate medium, Impedance matching can be achieved.

  In addition, although the example described in FIG. 10 demonstrated the example which performs an impedance change using a circuit element, for example, as shown in FIG. 11, an impedance change means is a contactor which can contact a human body ( 1101). The “contactor” (1101) indicates a portion that comes into contact with the human body. This is because the human body itself can change the impedance as a resistance component. Note that the contactor may include the resistance element already described, and may be configured to reduce the influence on the human body.

  FIG. 12 is a diagram illustrating an example of a usage example of the RF tag system when the end processing unit (1204) is used. The intermediate medium (1201) in FIG. 12 has portions extending from the pickup unit (1202) divided in parallel, and each has a communication unit (1203A) and a communication unit (1203B). Each communication unit has an end processing unit (1204A) and an end processing unit (1204B) at the end. In the case of FIG. 12, since it is possible to control whether each communication unit can perform communication by termination processing in each end processing unit, for example, although the communication unit (1203A) is installed, this communication unit (1203A) In the case where it is not desired to temporarily communicate with the non-contact tag, the communication unit (1203A) cannot perform communication by not performing the termination process in the edge processing unit (1204A). Therefore, this purpose can be realized. Note that when the communication unit (1203A) wants to resume communication again, the end processing unit (1204A) can perform the termination process to easily resume communication. By providing the end processing unit in this way, it is possible to independently control the availability of communication in each system even when there are a plurality of communication paths.

<Effect of Embodiment 2>
Since the RF tag system according to the present embodiment has an end processing unit, it is possible to control whether or not communication is possible in the communication unit, so that communication with a non-contact tag can be set and controlled flexibly and easily. It is possible to improve usability.

<< Embodiment 3 >>
<Outline of Embodiment 3>
The RF tag system in the present embodiment is characterized in that the intermediate medium described in the first embodiment is configured as the same loop conductor.

<Configuration of Embodiment 3>
The configuration of the RF tag system in the present embodiment is composed of a non-contact tag, an interrogator, and an intermediate medium, similar to that described in the first embodiment. The non-contact tag and the interrogator are the same as those described in the first embodiment. The intermediate medium of the present embodiment is the intermediate medium described in the first embodiment, and the pickup unit, the extension unit, and the communication unit are configured as a part of the same loop-shaped conductor. It is.

  FIG. 13 is a diagram illustrating an example of this embodiment. The intermediate medium (1301) indicated by a bold line in FIG. 13 is installed along the outer shape of the door, for example, and can mediate communication between the antenna (1302) of the interrogator and the non-contact tag (1303). Moreover, in the example of FIG. 13, the loop-shaped conductor has shown the example comprised by the closed loop shape which short-circuited the edge part of the conductor. In the example of FIG. 13, when the non-contact tag (1303) enters the internal space surrounded by the intermediate medium (1301), communication between the non-contact tag and the interrogator (not shown) can be performed. It becomes possible. In addition, although FIG. 13 demonstrated as an example of a door, an intermediate medium can also be installed along a bookshelf besides this. For example, it is possible to control communication in each stage by installing an intermediate medium in each of a plurality of stages of the bookshelf and providing the end processing unit described in the second embodiment. FIG. 14 shows another example in the present embodiment. FIG. 14 shows a state in which the intermediate medium (1401) that is a loop conductor is rotatably connected to the interrogator with antenna (1402). By rotating the intermediate medium and changing the angle in this way, it is possible to communicate with the non-contact tag via the intermediate medium without holding the non-contact tag over the interrogator antenna. By changing the angle of the intermediate medium and making it parallel to the surface of the contactless tag, the number of induced magnetic fluxes passing through the antenna in the contactless tag can be increased, and induced power is supplied to the contactless tag. Because it can be done.

  It should be noted that the “same loop-shaped conductor” is only required to form one loop shape when the intermediate medium is viewed as a whole. For example, even when a switch is provided in the middle of a loop and the switch is in an open state, the same loop shape is formed including the open switch. . Moreover, you may have the communication part comprised by another loop shape in the same loop conductor (following, in this specification, the same).

<Effect of Embodiment 3>
In the RF tag system according to the present embodiment, the pickup unit, the extension unit, and the communication unit that constitute the intermediate medium are configured as a part of the same loop-shaped conductor. It is possible to communicate with the contact tag. For this reason, it is possible to flexibly change the communication position with the non-contact tag while using the existing interrogator for the management of entry / exit and inventory management.

<< Embodiment 4 >>
<Outline of Embodiment 4>
The RF tag system in the present embodiment is characterized in that the intermediate medium described in the third embodiment has a configuration capable of controlling whether communication is possible. The intermediate medium described in the second embodiment is capable of such control at its end, but this embodiment is different in that such control is possible in any part of the loop-shaped conductor. is there.

<Configuration of Embodiment 4>
As in the third embodiment, the RF tag system in the present embodiment includes a non-contact tag, an interrogator, and an intermediate medium. The non-contact tag and the interrogator are the same as those described in the first embodiment. The intermediate medium according to the present embodiment is the intermediate medium described in the third embodiment, and further includes a switch unit. Since the non-contact tag and the interrogator are the same as those described in the first embodiment, description thereof is omitted here.

  FIG. 15 is a diagram illustrating an example of a usage example of the RF tag system when the switch unit (1504A, B) is used. The intermediate medium (1501A, B) in FIG. 15 is composed of independent and identical loop-shaped conductors each having a pickup unit (1502A, B), a communication unit (1503A, B), and a switch unit (1504A, B). The Although the extension is not clearly shown in the drawing, the intermediate medium has the same as in the third embodiment. By controlling the short-circuit / opening of the switch unit (1504A, B) of each intermediate medium (1501A, B), it is possible to control the availability of communication of each communication unit in each intermediate medium. That is, the switch unit can include a short-circuit / opening unit for controlling whether communication is possible. For this reason, for example, when the communication unit (1503A) is installed, but the communication unit (1503A) does not want to temporarily communicate with the non-contact tag, the switch unit (1504A) performs the opening process. By doing so, the communication unit (1503A) can no longer perform communication, and this purpose can be realized. In addition, when it is desired to restart communication again in the communication unit (1503A), communication can be easily restarted by performing a short circuit process in the switch unit (1504A). By providing the switch unit in this way, it is possible to independently control the availability of communication in each system even when there are a plurality of communication paths using a loop-shaped intermediate medium. The short-circuit / opening means included in the switch unit may include, for example, a mechanical switch, or may include an electric switch.

<Effect of Embodiment 4>
Since the RF tag system according to the present embodiment has a switch unit, it is possible to control whether or not communication is possible in the loop conductor and in the communication unit, so that communication with a non-contact tag is flexible and easy. Can be set and controlled, and usability can be expected to improve.

<< Embodiment 5 >>
<Outline of Embodiment 5>
The RF tag system in the present embodiment is characterized in that the intermediate medium described in any of the first to fourth embodiments can be used as a handy antenna.

<Configuration of Embodiment 5>
The RF tag system according to the present embodiment includes a non-contact tag, an interrogator, and an intermediate medium as described in any of the first to fourth embodiments. The non-contact tag and the interrogator are the same as those described in the first embodiment. The intermediate medium in the present embodiment is the intermediate medium described in any one of the first to fourth embodiments, and further includes a gripping unit that can be held by the communication unit.

  FIG. 16 is a diagram illustrating an example of the present embodiment. As shown in FIG. 16, the communication unit (1603) has a gripping means (1604). The gripping means is made of a resin material such as plastic. And the part which communicates with the non-contact tag of a communication part (1603) becomes a loop shape, and is covered with the resin material similarly to the holding means. It is possible to communicate with the non-contact tag by holding the communication unit (1603) over the non-contact tag. An intermediate medium having such a gripping means can be effectively used in a store such as a supermarket. In other words, at supermarket cashiers, etc., accounting is performed using a stationary interrogator, but by using the intermediate medium of this embodiment, a handy antenna can be quickly and easily installed on the stationary interrogator. It becomes possible to add simply. For this reason, for products that cannot be read by the stationary interrogator, exchange of cash registers and the like can be carried out without delay by appropriately using a handy antenna that uses this intermediate medium. Note that the gripping means may include a switch capable of short-circuiting and opening the loop shape in order to control whether communication is possible in the communication unit.

<Effect of Embodiment 5>
In the RF tag system according to the present embodiment, since the communication unit of the intermediate medium has a gripping unit, the intermediate medium can be used as a handy antenna. Also, when actually used as a handy antenna, it can be used by placing this intermediate medium in the vicinity of the antenna of an existing interrogator, so it can communicate with a non-contact tag simply and quickly. Can do.

Conceptual diagram for explaining the first embodiment Block diagram of contactless tag Interrogator block diagram The figure for demonstrating the structure of Embodiment 1. FIG. 1st figure which shows an example of the pick-up part of Embodiment 1. The 2nd figure which shows an example of the pick-up part of Embodiment 1. The figure which shows an example of the communication part of Embodiment 1. Diagram showing an example of using multiple intermediate media The figure for demonstrating the structure of Embodiment 2. FIG. The figure which shows an example of the edge part process part of Embodiment 2. The figure which shows the example using the contactor of Embodiment 2. The figure which shows an example in which the communication part of Embodiment 2 is comprised in parallel. The figure which shows the example whose intermediate medium of Embodiment 3 is the same loop-shaped conductor The figure which shows a mode that the intermediate medium of Embodiment 3 is attached rotatably. The figure which shows an example in which the intermediate medium of Embodiment 4 is comprised in parallel. The figure which shows that the intermediate medium of Embodiment 5 can be used as a handy antenna. A diagram for explaining a conventional example

Explanation of symbols

300 Interrogator 301 Interrogator Antenna 400 Intermediate Medium 401 Extension Portion 402 Pickup Portion 403 Communication Portion 404 Contactless Tag

Claims (23)

An RF tag system comprising a contactless tag, an interrogator, and an intermediate medium that mediates communication between the two,
The intermediate medium is
RF having an extension that is a conductor having no feeding point, which is extended from the interrogator antenna so that it can communicate with the non-contact tag via the intermediate medium even in the place other than the sky or the vicinity of the interrogator antenna Tag system. The intermediate medium is
A pickup unit that is arranged near the interrogator antenna and picks up a signal generated from the interrogator antenna;
A communication unit that reproduces a magnetic field to perform electromagnetic induction communication with a non-contact tag;
The RF tag system according to claim 1, comprising:   The electromagnetic induction system according to claim 2, wherein the intermediate medium includes a plurality of communication units.   4. The RF tag system according to claim 2, wherein the pickup unit includes first conductor means along a part of a conductor of an interrogator antenna. 5.   4. The RF tag system according to claim 2, wherein the pickup unit has a loop-shaped second conductor means disposed in the vicinity of the antenna of the interrogator. 5.   6. The RF tag system according to claim 1, wherein the extension portion is configured by a power supply cable.   The RF tag system according to any one of claims 1 to 5, wherein the extension portion is configured by a communication cable.   The RF tag system according to any one of claims 2 to 7, wherein the communication unit is configured in a loop shape that does not contact a conductor.   The RF tag system according to claim 2, wherein the communication unit is configured by bending a conductor.   The RF tag system according to any one of claims 2 to 9, wherein the intermediate medium has an end processing unit for controlling whether or not communication with a non-contact tag in the communication unit is possible.   The RF tag system according to claim 10, wherein the end processing unit includes impedance changing means for controlling whether communication is possible.   The RF tag system according to claim 11, wherein the impedance changing means includes a first switch for connecting the extension conductor and the end.   The RF tag system according to claim 11, wherein the impedance changing unit includes a second switch for connecting the resistance element and the end.   The RF tag system according to claim 11, wherein the impedance changing means includes a third switch for connecting the coil and the end.   The RF tag system according to claim 11, wherein the impedance changing unit includes a fourth switch for connecting a capacitor and an end.   The RF tag system according to claim 11, wherein the impedance changing unit includes a contactor capable of contacting a human body.   The RF tag system according to any one of claims 2 to 9, wherein the pickup unit, the extension unit, and the communication unit are configured as a part of the same loop-shaped conductor.   The RF tag system according to claim 17, wherein the loop-shaped conductor is configured in a closed loop shape in which an end portion of the conductor is short-circuited.   The RF tag system according to claim 18, wherein the loop-shaped conductor has a switch unit for controlling whether or not communication with the non-contact tag is possible.   The RF tag system according to claim 19, wherein the switch unit includes a short-circuit / opening unit for controlling whether communication is possible.   The RF tag system according to claim 20, wherein the short-circuit / opening means includes a mechanical switch.   The RF tag system according to claim 20, wherein the short-circuit / opening means includes an electric switch.   The RF tag system according to any one of claims 2 to 22, wherein the communication unit includes a gripping means that can be held by hand.

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