JP2006186943A - Radio tag communication device, radio tag communication system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology for performing communications suitably among two or more kinds of radio tags. <P>SOLUTION: A bandpass filter 32 functioning as a signal separation unit for separating a received signal from two or more kinds of radio tags to two or more signal regions is provided. Then, communication of information can be performed concurrently among two or more kinds of radio tags with signal regions different from each other, so adverse effects, such as superposition of transmission signal and increase of communication data, can be prevented. As a result, the radio tag communication device 12 for performing communication suitably among two or more kinds of radio tags can be offered. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an improvement in a wireless tag communication device and a wireless tag communication system that perform information communication with a predetermined wireless tag in a contactless manner, and in particular, preferably performs communication with a plurality of types of wireless tags. For technology.

  2. Description of the Related Art An RFID (Radio Frequency Identification) system is known in which information is read out in a non-contact manner by a predetermined wireless tag communication device (interrogator) from a small wireless tag (responder) in which predetermined information is stored. This RFID system is capable of reading information stored in a wireless tag by communication with the wireless tag communication device even when the wireless tag is dirty or disposed at an invisible position. Therefore, practical use is expected in various fields such as merchandise management and inspection processes.

  As one usage form of such an RFID system, a technique for detecting a position in a limited space such as a room has been proposed. For example, this is the destination guidance system described in Patent Document 1. According to this technology, by attaching a wireless tag to a display shelf or the like to be guided, the position can be displayed on the floor map.

JP 2001-116583 A

  By the way, considering the practical use of the RFID system for article management and the like, in addition to the above-described wireless tag having location information for position detection (hereinafter referred to as a location tag), it is attached to an article etc. to manage them. In some cases, communication with a wireless tag having the management information (hereinafter referred to as an article tag) is desired. However, in the conventional technology, communication with the place tag and communication with the article tag are performed at the same time, and there is a possibility that correct communication may not be performed due to superimposition of communication signals. In addition, there is an adverse effect that communication data increases by performing such communication simultaneously. For this reason, development of the technique which can communicate suitably between several types of wireless tag was calculated | required.

  The present invention has been made against the background of the above circumstances, and an object of the present invention is to provide a technology capable of suitably communicating with a plurality of types of wireless tags.

  In order to achieve such an object, the gist of the first invention is that a transmission signal is transmitted to a predetermined wireless tag, and a reply signal returned from the wireless tag according to the transmission signal is transmitted. A wireless tag communication device that receives and communicates information with the wireless tag, comprising a signal dividing unit for dividing a received signal from the wireless tag into a plurality of signal regions Is.

  In order to achieve the above object, the gist of the second invention is a radio tag communication system using the radio tag communication apparatus of the first invention, wherein a plurality of types of radio signals having different signal areas are used. Information is communicated with a tag.

  As described above, according to the first aspect of the present invention, since the signal dividing unit for dividing the received signal from the wireless tag into a plurality of signal areas is provided, it is possible to connect between a plurality of types of wireless tags having different signal areas. Thus, information can be communicated simultaneously, and adverse effects such as superimposition of communication signals and an increase in communication errors can be prevented. That is, it is possible to provide a wireless tag communication device that can suitably communicate with a plurality of types of wireless tags.

  In the first invention, it is preferable that the signal dividing unit divides received signals from a plurality of types of wireless tags having different functions into a plurality of signal areas according to functions. In this way, information can be communicated simultaneously with a plurality of types of wireless tags having different functions.

  Preferably, an A / D conversion unit that converts a received signal from the wireless tag into a digital signal, and the signal dividing unit divides the received signal into a plurality of signal regions by digital signal processing. It is. In this way, by using digital signal processing, it is possible to perform frequency decomposition using a filter bank or FIR (Finite Impulse Response) filter.

  Preferably, a reception phased array control unit that includes a plurality of antenna elements and controls reception directivity by controlling the phase of each received signal from the wireless tag received by the plurality of antenna elements. Is. In this way, the direction of the wireless tag can be suitably specified.

  Preferably, the apparatus includes a plurality of antenna elements, and a transmission phased array control unit that controls transmission directivity by controlling the phase of each transmission signal transmitted from the plurality of antenna elements. In this way, the direction of the wireless tag can be suitably specified.

  In addition, according to the second aspect of the present invention, information is communicated with a plurality of types of wireless tags having different signal areas, so that adverse effects such as superimposition of communication signals and an increase in communication errors can be prevented. That is, it is possible to provide a wireless tag communication system that can suitably communicate with a plurality of types of wireless tags.

  In the second invention, preferably, the plurality of types of wireless tags have different modulation frequencies. In this way, the signal areas of the plurality of types of wireless tags can be distinguished in a practical manner.

  Preferably, at least one of the plurality of types of wireless tags communicates information with the wireless tag communication device by frequency modulation. In this way, communication signal superposition can be prevented in a practical manner.

  Preferably, the wireless tag that performs frequency modulation performs frequency hopping that selects any one of a plurality of frequencies and uses it as a center frequency of the modulation frequency. In this way, it is possible to more suitably prevent communication signals from being superimposed, and communication can be established correctly.

  Preferably, at least one type of wireless tag among the plurality of types of wireless tags returns a reply signal to all transmission commands transmitted from the wireless tag communication device. In this way, it is not necessary to send a transmission command to the target wireless tag, and simultaneous communication can be suitably performed with the plurality of types of wireless tags.

  Preferably, at least one of the plurality of types of wireless tags is a semi-passive tag having a power supply device. In this way, stable communication is possible even when the modulation frequency of the target wireless tag is high and a large amount of energy is required to generate a modulation signal.

  Preferably, the wireless tag communication device processes received signals from a plurality of types of wireless tags received at the same time in association with each other. In this way, complex information processing can be performed using the plurality of types of wireless tags.

  Preferably, at least one type of wireless tag among the plurality of types of wireless tags is a tag that is provided in a fixed position at a predetermined location and has location information indicating the location. If it does in this way, information about a place can be acquired in a practical mode.

  Preferably, at least one type of wireless tag among the plurality of types of wireless tags is a tag attached to an article and having management information for managing the article. In this way, article management information can be acquired in a practical manner.

  Preferably, the wireless tag communication device includes a plurality of antenna elements, and controls reception directivity by controlling a phase of each received signal from the wireless tag received by the plurality of antenna elements. An RFID tag communication device having a reception phased array control unit or a transmission phased array control unit that controls transmission directivity by controlling the phase of each transmission signal transmitted from the plurality of antenna elements. The plurality of types of wireless tags are arranged around the apparatus, and received signals received simultaneously from the plurality of types of wireless tags are processed in association with each other. If it does in this way, the direction of the goods with which the tag which has the management information was pasted can be detected suitably by referring to the information about the place shown by the tag which has the location information.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a diagram for explaining a radio tag communication system 10 (hereinafter referred to as a communication system 10) according to an embodiment of the present invention. Similarly, the communication system 10 includes a wireless tag communication device 12 according to an embodiment of the present invention and a plurality of types (two types in FIG. 1) of wireless signals having different signal areas as communication targets of the wireless tag communication device 12. This is a so-called RFID (Radio Frequency Identification) system composed of tags 14 and 16, wherein the RFID tag communication device 12 functions as an interrogator of the RFID system, and the RFID tags 14 and 16 function as responders. That is, when the interrogation wave F _c that is a transmission signal is transmitted from the radio tag communication apparatus 12 toward the radio tags 14 and 16, predetermined information is received in the radio tags 14 and 16 that have received the interrogation wave F _c. The interrogation wave F _c is modulated by the signal (data), and the response waves F _r1 , F _r2 , F _r3 , F _r4 (hereinafter simply referred to as the response wave F _r unless otherwise distinguished) are returned signals. By sending a reply to the wireless tag communication device 12, information is communicated between the wireless tag communication device 12 and the wireless tags 14 and 16.

  The communication system 10 includes a single or multiple (three in FIG. 1) first wireless tags 14a, 14b, and 14c as communication targets of the wireless tag communication device 12, and a single or multiple (FIG. 1). Is a single) second wireless tag 16. The first wireless tag 14 is preferably a tag that is attached to a predetermined article and has management information for managing the article, and is referred to as an article tag 14 in the following description. The second wireless tag 16 is preferably a tag that is provided at a fixed location and has location information indicating the location, and is referred to as a location tag 16 in the following description. As described above, the communication system 10 according to the present embodiment performs information communication between a plurality of types (two types in the present embodiment) of wireless tags 14 and 16 having different signal areas.

FIG. 2 is a diagram illustrating the configuration of the wireless tag communication device 12. As shown in FIG. 2, the wireless tag communication device 12 reads and writes information with respect to the product tag 14 and detects the direction and position of the product tag 14 and the location tag 16. Information is communicated with the tag 16, and a transmission command generator 18 that generates and outputs a predetermined transmission signal (transmission command) and a carrier signal generator 20 that generates a carrier signal of a predetermined frequency. A modulation unit 22 that modulates the carrier signal based on the transmission command by multiplying the transmission signal output from the transmission command generation unit 18 and the carrier signal output from the carrier signal generation unit 20; An amplification unit 24 that amplifies the transmission signal modulated by the modulation unit 22, and the transmission signal amplified by the amplification unit 24 is passed as an interrogation wave F _c . Transmits toward the article tag 14 or location tag 16 is signal subject, the antenna 26 of the transmitting and receiving shared receiving a response wave F _r sent back from their article tag 14 or location tag 16 in response to the interrogation wave F _c And a demodulator 30 that demodulates the received signal by multiplying the received signal received by the antenna 26 with the carrier signal output from the carrier signal generator 20, and the transmission output from the amplifier 24 A transmission / reception separating unit 28 for supplying a signal to the antenna 26 and a reception signal received by the antenna 26 to the demodulation unit 30; and a predetermined frequency band among the reception signals demodulated by the demodulation unit 30 A plurality of (four in FIG. 2) bandpass filters 32a and 32b (hereinafter not particularly distinguished) Is simply referred to as a band-pass filter 32), and a first reception signal processing unit 34a and a second reception signal processing unit 34b that respectively process reception signals divided into signal regions corresponding to the band-pass filters 32a and 32b. (Hereinafter, simply referred to as a reception signal processing unit 34 unless otherwise distinguished). Here, as the transmission / reception separation unit 28, a circulator or a directional coupler is preferably used. Further, when the article tag 14 and the place tag 16 perform a reply, the carrier wave is transmitted as an unmodulated carrier signal, and a reply signal is obtained by reflecting and modulating the carrier wave signal at the article tag 14 or the place tag 16. It becomes.

The band-pass filter 32 passes only signals in a predetermined frequency band among the reception signals received by the antenna 26, thereby dividing the reception signal received by the antenna 26 into a plurality of signal regions. Functions as a signal dividing unit. For example, the bandpass filter 32a corresponds to an article tag channel used by the article tag 14, and is set to pass a reception signal (article tag data) corresponding to the response wave _Fr from the article tag 14. ing. Thereby, only the reception signal corresponding to the response wave _Fr from the article tag 14 is supplied to the first reception signal processing unit 34a, and the processing of such a signal is performed exclusively. The band-pass filter 32b corresponds to a location tag channel used by the location tag 16, and passes a reception signal (location tag data) corresponding to the response wave _Fr4 from the location tag 16 using the channel. Is set to Thereby, only the reception signal corresponding to the response wave F _r4 from the location tag 16 is supplied to the second reception signal processing unit 34b, and the processing of such a signal is performed exclusively.

FIG. 3 is a diagram illustrating the configuration of the article tag 14. As shown in FIG. 3, the article tag 14 includes an antenna unit 36 for transmitting / receiving signals to / from the RFID tag communication device 12 and a signal received by the antenna unit 36. An IC circuit unit 38 is provided. The IC circuit unit 38 rectifies the interrogation wave F _c received from the RFID tag communication apparatus 12 received by the antenna unit 36 and the energy of the interrogation wave F _c rectified by the rectification unit 40. Functions as a power supply unit 42 for storing, a clock extraction unit 44 that extracts a clock signal from the carrier wave received by the antenna unit 36 and supplies the clock signal to the control unit 50, and an information storage unit that can store a predetermined information signal The product tag 14 via the memory unit 46, the modem unit 48 connected to the antenna unit 36 for modulating and demodulating the signal, the rectifier unit 40, the clock extracting unit 44, the modem unit 48, and the like. And a control unit 50 for controlling the function. The control unit 50 performs control to store the predetermined information in the memory unit 46 by communicating with the RFID tag communication apparatus 12, and transmits the interrogation wave F _c received by the antenna unit 36 to the modulation / demodulation unit 48. , Based on the information signal stored in the memory unit 46, the signal is modulated as a signal using a modulation frequency corresponding to the article tag channel, and is then reflected back from the antenna unit 36 as a response wave F _r. Execute. Preferably, the article tag 14 returns a response signal to a predetermined command among transmission commands transmitted from the wireless tag communication device 12.

FIG. 4 is a diagram for explaining the configuration of the location tag 16. This place tag 16 is configured to include an antenna section 36 and an IC circuit section 38a as in the case of the article tag 14, and parts common to the above-described article tag 14 in FIG. Therefore, the explanation is omitted. The control unit 50a included in the IC circuit unit 38a performs control for storing the predetermined information in the memory unit 46 by communicating with the RFID tag communication device 12, and the interrogation wave F received by the antenna unit 36. Control for modulating and demodulating _c as a signal using a modulation frequency corresponding to the location tag channel based on the information signal stored in the memory unit 46 in the modulation / demodulation unit 48 and then reflecting the response wave F _r4 from the antenna unit 36 Execute basic control such as. Also, the location tag 16, as shown in FIG. 4 has a predetermined power supply 52, the power supply unit 42, in addition to the energy of the interrogation wave rectified F _c by the rectifier unit 40, the power supply The energy supplied from the device 52 can be used as a power source. The power supply device 52 is preferably provided externally as a separate body from the IC circuit unit 38a. In other words, the place tag 16 is a semi-passive tag that includes a predetermined power supply device 52 and operates by energy supplied from the power supply device 52. Preferably, the place tag 16 returns a reply signal to all transmission commands transmitted from the RFID tag communication apparatus 12.

The article tag 14 and the place tag 16 communicate information with the wireless tag communication device 12 through the modulation / demodulation unit 48 by frequency modulation. FIG. 5 is an example of a frequency spectrum indicating a modulation frequency used for modulation by the article tag 14 and the place tag 16, where f _p0 is a modulation frequency used for modulation by the article tag 14, and f _p1 is the place tag. 16 shows modulation frequencies used for modulation by 16 respectively. That is, f _p0 indicates an article tag channel, and f _p1 indicates a location tag channel. The radio when the tag interrogating wave F _c which is transmitted from the communication device 12 is modulated by frequency modulation, a pair of sideband signals around the frequencies of the corresponding interrogating wave F _c to the respective modulation frequency (sideband signal ) Is formed. FIG. 6 is a frequency spectrum showing the carrier wave f _c and the sideband signal of the response wave F _r when the interrogation wave F _c having the frequency f _c is modulated by the modulation frequency shown in FIG. 5, and f _c ± f _p0 Indicates the response wave F _r from the article tag 14, and f _c ± f _p1 indicates the response wave F _r from the place tag 16. Further, the modulation frequency of the location tag 16 is higher than the modulation frequency of the article tag 14 so that they do not overlap each other.

FIG. 7 is a diagram showing the relationship between the main carrier F _c and the response wave F _r used in the communication system 10. The article tag 14 responds to each communication timing such that the article tag 14a responds at timing T1, the article tag 14b responds at timing T2, and the article tag 14c responds at timing T3. Selection is performed by a transmission command transmitted from the wireless tag communication device 12. Since the place tag 16 replies to all transmission commands regardless of the contents of the transmission command, a response wave having a frequency spectrum of f _c ± f _p1 is generated at all timings.

  FIG. 8 is a diagram for explaining a practical use form of the communication system 10 according to the present embodiment. As shown in FIG. 8, the place tag 16 is a tag that is provided in a fixed position with respect to a predetermined chamber 54 and has place information indicating a place in the chamber 54. The article tag 14 is It is a tag having management information that is affixed to articles installed in the chamber 54 to manage those articles. Here, the mode in which the article tag 14 is attached to each of the four books from the first volume to the fourth volume and the three files from the file 1 to the file 3 is shown. Seven article tags 14 each having a different identification code (ID) are provided.

  The wireless tag communication device 12 is preferably a portable wireless tag communication device (handy reader) provided to be movable with respect to the chamber 54, and a user carries the wireless tag communication device 12, The article tag 14 or the location tag 16 is detected while referring to a screen displayed on the display unit 56 (enlarged in FIG. 8) of the RFID tag communication apparatus 12. Further, the communication system 10 is provided with a database 58 for storing information related to the article tag 14, and the wireless tag communication device 12 stores information on the database 58 via a predetermined interface (not shown). Read / write is possible.

  FIG. 9 is a diagram showing the relationship between the IDs of the article tags 14 stored in the database 58 and the management information of the articles managed by the article tags 14. As shown in FIG. 9, in the database 58, an article tag 14 with an ID “145604” is affixed to “Volume 4”, and the chamber 54 is placed at “2004/10/01 10:20”. It is possible to memorize information that it is confirmed that “is”. The wireless tag communication device 12 processes received signals from a plurality of types of wireless tags received at the same time in association with each other. For example, when the place tag 16 provided in a fixed position with respect to the chamber 54 is detected at the same time when a predetermined article tag 14 is detected, name information (management information) that is an ID of each of the article tags 14 is detected. And the area information (location information) which is the ID of the location tag 16 are processed in association with each other. As a result, the position tag 16 provided in a fixed position with respect to the chamber 54 detects the position of the wireless tag communication device 12 with respect to the chamber 54 and detects the position of the article tag 14 detected at the same time. The accurate position of the tag 14 can be detected, and information related to the tag 14 is stored in the database 58, so that the articles in the chamber 54 can be suitably managed.

  FIG. 10 is a flowchart for explaining article list display control corresponding to the embodiment of FIG. 8 by the wireless tag communication device 12, and is repeatedly executed at a predetermined cycle.

First, in step SA0 (hereinafter step is omitted), i = 1 is set. Next, in SA1, the i-th ID in the article list is selected, and the transmission command generation unit 18 generates a transmission command representing a “Scroll ID” command, which is transmitted through the modulation unit 22, the amplification unit 24, and the like. is transmitted to the said article tag 14 and places the tag 16 as interrogating wave F _c from the antenna 26. This “Scroll ID” command is a command for requesting a reply to a tag having a designated ID. Next, in SA2, it is determined whether or not a response wave _Fr is returned from the article tag 14 or the place tag 16. If the determination of SA2 is negative, the operation of SA5 to SA8 is skipped, and the processing after SA9 is executed. If the determination of SA2 is positive, that is, from the article tag 14 or the location tag 16 If it is determined that a reply response wave F _r of at SA5, the response wave F the article tag 14 obtained from return signals _r, where the tag 16 name information of each ID is the database 58 To be acquired. Next, in SA6, a name list of the acquired ID is created, and information on the place tag 16 is displayed on the display unit 56. Next, in SA7, it is determined whether or not an update operation for the database 58 has been performed. If the determination at SA7 is negative, the processing after SA9 is executed. If the determination at SA7 is affirmative, the information of the location tag 16 and the stored ID list are associated with each other at SA8. After being transmitted to the database 58, the processing from SA9 is executed. In SA9, it is determined whether or not the i-th ID is the last item in the article list. If the determination of SA9 is negative, in SA10, 1 is added to i, and then the processing after SA1 is executed. If the determination of SA9 is affirmative, this routine is used. Be terminated.

  As described above, according to the present embodiment, since the band-pass filter 32 functioning as a signal dividing unit for dividing the received signals from the article tag 14 and the place tag 16 into separate signal areas is provided, the signals are mutually transmitted. Information can be communicated simultaneously with a plurality of types of wireless tags 14 and 16 in different areas, and adverse effects such as overlapping of communication signals and increase in communication errors can be prevented. That is, it is possible to provide the wireless tag communication device 12 that can suitably communicate with a plurality of types of wireless tags 14 and 16.

  The bandpass filter 32 divides received signals from a plurality of types of wireless tags 4 and 16 having different functions into a plurality of signal areas for each function, and thus a plurality of types of wireless tags 14 having different functions. , 16 can simultaneously communicate information.

  Further, since the communication system 10 communicates information with a plurality of types of wireless tags 14 and 16 having different signal areas, it is possible to prevent adverse effects such as communication signal superposition and increase in communication errors. . That is, it is possible to provide the communication system 10 that can suitably perform communication with a plurality of types of wireless tags.

  Further, since the plurality of types of wireless tags 14 and 16 have different modulation frequencies, the signal areas of the plurality of types of wireless tags can be distinguished from each other in a practical manner.

  In addition, since the wireless tags 14 and 16 perform information communication with the wireless tag communication device 12 by frequency modulation, it is possible to prevent communication signals from being superimposed in a practical manner.

  Further, since the location tag 16 replies a reply signal to all transmission commands transmitted from the wireless tag communication device 12, it is preferably used with the plurality of types of wireless tags 14 and 16. Simultaneous communication can be performed.

  Further, since the location tag 16 is a semi-passive tag having the power supply device 52, stable communication is possible even when the modulation frequency is high.

  In addition, since the wireless tag communication device 12 processes received signals from a plurality of types of wireless tags 14 and 16 received at the same time, the wireless tag communication device 12 uses the plurality of types of wireless tags 14 and 16. Complex information processing can be performed.

  Further, since the location tag 16 is a tag that is provided in a fixed location at a predetermined location and has location information that indicates the location, information on the location can be acquired in a practical manner.

  Further, since the article tag 14 is a tag having management information that is attached to a predetermined article and manages the article, the article management information can be acquired in a practical manner.

  Next, another preferred embodiment of the present invention will be described in detail with reference to the drawings. In addition, regarding the following description, the same code | symbol is attached | subjected about the part which is common in the Example mentioned above, and the description is abbreviate | omitted.

  FIG. 11 is a diagram for explaining a mode of use in another embodiment of the present invention. In this embodiment, a plurality of (two in FIG. 11) place tags 17 are provided in fixed positions in the respective areas within the shelf 60 partitioned into the same number of areas, and the target article tag 14 faces the paper surface. Are disposed in the left region A. In addition, in the region B on the right side of the page, a non-target article tag 14 'is disposed. These article tag 14 'and place tag 17 have the same configuration as the article tag 14 and place tag 16 described above with reference to FIGS. Here, the two place tags 17 provided at fixed positions in the shelf 60 have place information indicating the areas A and B, respectively, and the RFID tag communication apparatus 12 receives the article received at the same time. The received signals from the tag 14 and the location tag 17 are processed in association with each other. Thereby, by referring to the location information of the location tag 17 detected at the same time as the target product tag 14, it is possible to detect whether the product tag 14 exists in the region A or the region B. is there.

  FIG. 13 is a diagram illustrating the configuration of the wireless tag communication device 62 in FIG. As shown in FIG. 13, the RFID tag communication apparatus 62 of this embodiment includes an A / D converter 64 that converts a demodulated received signal output from the demodulator 30 into a digital signal, and its A / D. A DSP (Digital Signal Processor) 66 for processing the received signal converted into a digital signal by the conversion unit 64 is provided.

  The DSP 66 is a so-called microcomputer system that includes a CPU, a ROM, a RAM, and the like, and performs signal processing according to a program stored in advance in the ROM while using a temporary storage function of the RAM. Execute control etc. That is, in the RFID tag communication device 62, the band pass filter 32 and the received signal processing unit 34 described above are functionally included in the DSP 66, and the band pass filter 32 functioning as a signal dividing unit is a digital signal. The received signal is divided into a plurality of signal areas by processing.

The band-pass filter 32 passes only signals in a predetermined frequency band among the reception signals received by the antenna 26, thereby dividing the reception signal received by the antenna 26 into a plurality of signal regions. Functions as a signal dividing unit. For example, the bandpass filter 32a corresponds to an article tag channel used by the article tag 14, and is set to pass a reception signal (article tag data) corresponding to the response wave _Fr from the article tag 14. ing. Thereby, only the reception signal corresponding to the response wave _Fr from the article tag 14 is supplied to the first reception signal processing unit 34a, and the processing of such a signal is performed exclusively. The bandpass filter 32b corresponds to the first location tag channel used by the location tag 17, and a received signal (first location tag data) corresponding to the response wave _Fr from the location tag 17 using the channel. ) Is set to pass. Thereby, only the received signal corresponding to the response wave F _r from the place tag 17 using the first place tag channel is supplied to the second received signal processing section 34b, and the processing of such a signal is performed exclusively. . The bandpass filter 32c corresponds to the second location tag channel used by the location tag 17, and a received signal (second location tag data) corresponding to the response wave _Fr from the location tag 17 using the channel. ) Is set to pass. Thereby, only the received signal corresponding to the response wave F _r from the place tag 17 using the second place tag channel is supplied to the third received signal processing unit 34c, and the processing of such a signal is performed exclusively. . The band-pass filter 32d corresponds to the third place tag channel used by the place tag 17, and the received signal (third place tag data) corresponding to the response wave _Fr from the place tag 17 using the channel. ) Is set to pass. Thereby, only the received signal corresponding to the response wave F _r from the place tag 17 using the third place tag channel is supplied to the fourth received signal processing section 34d, and the processing of such a signal is performed exclusively. .

FIG. 15 is a diagram for explaining the configuration of the location tag 17. The place tag 17 includes an antenna part 36 and an IC circuit part 38b as in the case of the article tag 14, and the same reference numerals are given to the parts common to the article tag 14 of FIG. Therefore, the explanation is omitted. The IC circuit unit 38b includes a channel determination unit 53, which determines a location tag channel to be used for the response wave _Fr of the location tag 17 based on a predetermined method. In addition, the control unit 50b included in the IC circuit unit 38b performs control to store the predetermined information in the memory unit 46 by communicating with the RFID tag communication device 12, and the question received by the antenna unit 36. based waves F _c of the information signal stored in the memory unit 46 in the modem part 48, the response wave in terms of modulated as a signal using a modulation frequency that corresponds to the location tag channel determined by the channel determination unit 53 as F _r executes basic control such as control that reflects back from the antenna unit 36. Further, as shown in FIG. 15, the place tag 17 includes the above-described external power supply device 52, and the power supply unit 42 includes the energy of the interrogation wave F _c rectified by the rectification unit 40. The energy supplied from the power supply device 52 can be used as a power supply. In other words, the place tag 17 is a semi-passive tag that includes a predetermined power supply device 52 and operates by energy supplied from the power supply device 52. Further, preferably, the place tag 17 returns a reply signal to all transmission commands transmitted from the RFID tag communication apparatus 12.

The article tag 14 and the place tag 17 communicate information with the RFID tag communication device 62 through the modulation / demodulation unit 48 by frequency modulation. FIG. 16 is an example of a frequency spectrum showing a modulation frequency used for modulation by the article tag 14 and the place tag 17, _fp0 is a modulation frequency used for modulation by the article tag 14, and _fp1 is the place tag. 17, the modulation frequency when the first location tag channel is used for modulation, f _p2 is the modulation frequency when the second location tag channel is used for modulation by the location tag 17, and f _p3 is the location tag 17. The modulation frequencies when the third location tag channel is used for modulation are respectively shown. That is, f _p0 indicates the article tag channel, f _p1 indicates the first location tag channel, f _p2 indicates the second location tag channel, and f _p3 indicates the third location tag channel. The radio when the tag interrogating wave F _c which is transmitted from the communication device 12 is modulated by frequency modulation, a pair of sideband signals around the frequencies of the corresponding interrogating wave F _c to the respective modulation frequency (sideband signal ) Is formed. FIG. 17 is a frequency spectrum showing the carrier wave f _c and the sideband signal of the response wave F _r when the interrogation wave F _c having the frequency f _c is modulated by the modulation frequency shown in FIG. 16, and f _c ± f _p0 Represents the response wave F _r from the article tag 14, and f _c ± f _p1 , f _c ± f _p2 , and f _c ± f _p3 represent the response wave F _r from the tag 17. In this way, the modulation frequency of the place tag 17 is higher than the modulation frequency of the article tag 14 so that they do not overlap each other.

FIG. 18 is a diagram showing the relationship between the main carrier wave F _c and the response wave F _r used in the communication system 10. The article tag 14 responds to each communication timing such that the article tag 14a responds at timing T1, the article tag 14b responds at timing T2, and the article tag 14c responds at timing T3. Selection is performed by a transmission command transmitted from the wireless tag communication device 12. The place tag 17 replies to all transmission commands regardless of the contents of the transmission commands. At this time, the modulation frequency used for modulation by the location tag 17 is preferably frequency hopped in a different manner for each location tag 17. For example, as described above, in the location tag 17, the modulation frequency is determined according to the channel determined by the channel determination unit 53, and any one of f _c ± f _p1 , f _c ± f _p2 , and f _c ± f _p3 is determined. Although a sideband signal is generated, as shown in FIG. 18, the location tag 17a uses the first location tag channel at timing T1, uses the third location tag channel at timing T2, and the second at timing T3. Use the location tag channel. The location tag 17b uses the second location tag channel at timing T1, uses the first location tag channel at timing T2, and uses the third location tag channel at timing T3. That is, the response wave F _rb from the response wave F _ra and the location tag 16b from the location tag 16a is then frequency hopping based on a pseudo-random symbols, because the probability of collision with each other very small, their response Signals relating to modulation included in the wave F _r can be extracted independently. FIG. 18 shows only one (high frequency side) of a pair of sideband signals formed by modulation.

  FIG. 12 is a flowchart for explaining the article list display control corresponding to the embodiment of FIG. 11 by the wireless tag communication device 12, which is executed to know the position of the tag for search whose ID is already known. It is.

First, in SB1, a transmission signal representing a “Scroll ID” command is generated by the transmission command generation unit 18 and is transmitted from the antenna 26 to the shelf 60 as an interrogation wave F _c via the modulation unit 22 and the amplification unit 24. Sent to. This “Scroll ID” command is a command for requesting a reply to a tag having a designated ID. Next, in SB2, it is determined whether or not a response wave _Fr is returned from the article tag 14 indicating the target article. If the determination of SB2 is negative, the processing after SB1 is executed again, but if the determination of SB2 is positive, it is determined whether or not the ID of the place tag 17 has been correctly detected in SB2a. To do. When a plurality of place tags 17 use the same place tag channel, it becomes impossible to correctly receive the place tag 17 ID, so it is possible to determine whether or not the place tag use channels overlap. When the determination of SB2a is negative, the processing after SB1 is executed again. However, when the determination of SB2a is affirmative, it is determined that the location tag 17 has been correctly detected, and in SB3, the target The RSSI (Received Signal Strength Indicator) value of the place tag 16 detected simultaneously with the response from the article tag 14 is stored in the RAM or the like of the RFID tag communication device 12 (not shown). Next, in SB4, it is determined whether or not the RSSI in the region A of the shelf 60 is larger than the RSSI in the region B. If the determination of SB4 is affirmed, in SB5, information indicating that the article tag 14 indicating the target article is in the region A of the shelf 60 is displayed on the display unit 56, and then this routine is terminated. However, if the determination in SB4 is negative, in SB6, information indicating that the item tag 14 indicating the target item is in the region B of the shelf 60 is displayed on the display unit 56, and then this routine is executed. Be terminated.

  As described above, according to the present embodiment, the band pass filter 32 having the A / D conversion unit 64 that converts the received signals from the wireless tags 14 and 17 into digital signals, Since the received signal is divided into a plurality of signal regions by digital signal processing, frequency decomposition using a filter bank or FIR (Finite Impulse Response) filter can be performed by using digital signal processing.

  Further, since the wireless tag 17 performs frequency hopping used for reply by selecting one of a plurality of modulation frequencies, it is possible to suitably prevent communication signals from being superimposed and to establish communication correctly. be able to.

FIG. 14 is a diagram for explaining the configuration of an RFID tag communication apparatus 68 that is still another embodiment of the present invention. As shown in FIG. 14, the RFID tag communication apparatus 68 of the present embodiment multiplies the transmission signal output from the transmission command generation unit 18 and the modulation signal output from the carrier wave signal generation unit 20. A plurality (three in FIG. 14) of modulators 22a, 22b, and 22c (hereinafter simply referred to as modulators 22 unless otherwise specified) for modulating the transmission signal, and a plurality of modulators 22, respectively. A plurality (three in FIG. 14) of transmission phase control units 70a, 70b, and 70c (hereinafter simply referred to as transmission phase control unit 70 unless otherwise distinguished) for controlling the phase of the transmitted signal, A plurality (three in FIG. 14) of transmission amplitude control units 72a, 72b, 72c (hereinafter referred to as “transmission amplitude control units”) that control the amplitudes of transmission signals whose phases are controlled by the transmission phase control unit 70 Particularly simply referred to as a transmission amplitude control unit 72) when they are not distinguished by the plurality of transmission amplitude control section 72 to the article tag 14 or location tag 17 which is a communication target transmission signal amplified respectively as interrogating wave F _c transmits toward the antenna element 74a of a plurality of transmission and reception shared (FIG. 14, three) receiving a response wave F _r sent back from their article tag 14 or location tag 17 in response to the interrogation wave F _c, 74b 74c (hereinafter simply referred to as antenna elements 74 unless otherwise distinguished) and a plurality (three in FIG. 14) of reception phase control for controlling the phases of reception signals respectively received by the plurality of antenna elements 74 Units 76a, 76b, 76c (hereinafter simply referred to as reception phase control unit 76 unless otherwise distinguished) and the plurality of transmission amplitude control units 72. A plurality of (three in FIG. 14) transmission / reception separations are supplied to each antenna element 74 and the reception signals respectively received by the antenna elements 74 are supplied to the plurality of reception phase control units 76. Sections 28a, 28b, 28c (hereinafter simply referred to as transmission / reception separating section 28 unless otherwise distinguished) and a plurality of (FIG. 2) control amplitudes of received signals whose phases are controlled by the plurality of reception phase control sections 76, respectively. 14, three reception amplitude control units 78 a, 78 b, 78 c (hereinafter simply referred to as reception amplitude control unit 78 unless otherwise distinguished) and the reception signals amplified by the plurality of reception amplitude control units 78. Are multiplied by the modulation signal output from the carrier wave signal generation unit 20 to demodulate the reception signal (in FIG. 14, three). The control units 30a, 30b, and 30c (hereinafter, simply referred to as the demodulation unit 30 unless otherwise distinguished) are provided.

  In the wireless tag communication device 68, the transmission phase control unit 70, the transmission amplitude control unit 72, the reception phase control unit 76, and the reception amplitude control unit 78 constitute a directivity control unit 80. The directivity control unit 80 functions as a transmission phased array control unit that controls the transmission directivity by controlling the phase of each transmission signal transmitted from the plurality of antenna elements 74, and the plurality of antenna elements 74. It functions as a reception phased array control unit that controls the reception directivity by controlling the phase of each reception signal received by. Further, the phase and amplitude are controlled by the directivity control unit 80, and the received signals demodulated by the plurality of demodulation units 30 are converted into digital signals by the A / D conversion unit 64 and input to the DSP 66. It is like that. The DSP 66 functionally includes the bandpass filter 32 and the reception signal processing unit 34 described above, and divides the reception signal into a plurality of signal regions by digital signal processing, and converts the reception signals in each signal region. Process each one.

  The wireless tag communication device 68 is preferably used, for example, in the mode shown in FIG. 11 described above. That is, the wireless tag communication device 68 processes received signals from a plurality of types of wireless tags received at the same time in association with each other. For example, the article tag 14 around the wireless tag communication device 68, When the 14 'and the place tags 17a and 17b are provided, the received signals received simultaneously from the article tags 14 and 14' and the place tags 17a and 17b are processed in association with each other. By doing so, the position of the RFID tag communication device 68 with respect to the shelf 60 is detected by the place tags 17a and 17b provided in a fixed position with respect to the shelf 60, and the article tags 14 and 14 'detected simultaneously. Therefore, it is possible to detect the accurate positions of the article tags 14 and 14 '.

  Thus, according to the present embodiment, a plurality of antenna elements 74 are provided, and reception directivity is controlled by controlling the phases of the received signals from the wireless tags 14 and 17 received by the plurality of antenna elements 74. Since it has the directivity control part 80 which functions as a reception phased array control part which controls, the direction of the said wireless tags 14 and 17 can be specified suitably.

  Further, since it has a directivity control unit 80 that functions as a transmission phased array control unit that controls the transmission directivity by controlling the phase of each of the transmission signals transmitted from the plurality of antenna elements 74, a reply signal Can be limited, and the direction of the wireless tags 14 and 17 can be suitably specified.

  Further, the article tag 14 and the place tag 17 are arranged around the wireless tag communication device 68, and the reception signals received simultaneously from the article tag 14 and the place tag 17 are processed in association with each other. By referring to the information related to the place indicated by the place tag 17, the direction of the article to which the article tag 14 is attached can be suitably detected. In particular, when the wireless tag communication device 12 is a portable handy reader, the position of the article tag 14 is fixed with respect to the chamber 54 even when the article tag 14 is moving relative to the wireless tag communication device 12. The position of the article tag 14 can be reliably detected by referring to the relative positional relationship with the place tag 17 provided in the.

  The preferred embodiments of the present invention have been described in detail with reference to the drawings. However, the present invention is not limited to these embodiments, and may be implemented in other modes.

  For example, in the above-described embodiment, the usage mode of the communication system 10 using the wireless tag communication device 12 which is a handy reader provided so as to be movable with respect to the chamber 54 and the like has been described, but the present invention is not limited thereto. However, the present invention is also preferably applied to a communication system using a stationary reader provided in a fixed position with respect to a predetermined place.

  In the above-described embodiment, the band-pass filter 32 is provided as the signal dividing unit. However, the band-pass filter 32 may be used as long as the received signal can be divided into a plurality of signal regions. The signal division unit of the aspect can be appropriately used according to the design.

Further, although in the foregoing embodiments, the radio-frequency tag communication device 12 or the like, but there was one having an antenna 26 or a plurality of antenna elements 74 of both transmission and reception, the carrier wave F transmit antennas through for transmitting _{and c} a plurality of transmit antenna elements and a receiving antenna or a plurality of receiving antenna elements for receiving the reply wave F _r, may be a structure having separately, respectively.

  In the above-described embodiment, the RFID tag communication device 68 includes both a transmission phased array control unit that controls transmission directivity and a reception phased array control unit that controls reception directivity. Naturally, an embodiment having only one of them is also conceivable.

  In the above-described embodiment, the location tags 16 and 17 are semi-passive tags having a predetermined power supply device 52, but may be passive tags not having such a power supply device 52. The article tag 14 may be a semi-passive tag having a power supply device.

  In the above-described embodiment, the article tag 14 uses one modulation frequency, but may use a plurality of modulation frequencies selectively.

  In the above-described embodiment, the location tags 16 and 17 always return a response regardless of the content of the transmission command transmitted by the RFID tag communication device 12. However, the location tags 16 and 17 Further, a response may be returned based on the content of the transmission command transmitted by the RFID tag communication apparatus 12.

  In the above-described embodiment, the database 58 is provided separately from the RFID tag communication device 12 or the like, but the database 58 is built in the RFID tag communication device 12 or the like. It doesn't matter. Further, the database 58 is not necessarily provided.

  In addition, although not illustrated one by one, the present invention is implemented with various modifications within a range not departing from the gist thereof.

It is a figure explaining the radio | wireless tag communication system which is one Example of this invention. It is a figure explaining the structure of the RFID tag communication apparatus which is one Example of this invention. It is a figure explaining the structure of the article | item tag which is a communication object of the wireless tag communication apparatus of FIG. It is a figure explaining the structure of the place tag which is a communication object of the wireless tag communication apparatus of FIG. FIG. 5 is an example of a frequency spectrum showing a modulation frequency used for modulation by the article tag of FIG. 3 and the location tag of FIG. 4. 6 is a frequency spectrum showing a response wave when the interrogation wave transmitted from the RFID tag communication apparatus of FIG. 2 is modulated by the modulation frequency shown in FIG. 5. It is a figure which shows the relationship between the main carrier wave used in the communication system of FIG. 1, and a response wave, and demonstrates frequency hopping. It is a figure explaining the form of practical use of the communication system of FIG. It is a figure which shows the relationship between ID of the article tag of FIG. 3 memorize | stored in the database of FIG. 8, and the management information of the article managed by these article tags. 9 is a flowchart for explaining article list display control corresponding to the embodiment of FIG. 8 by the wireless tag communication device of FIG. 2. It is a figure explaining the other practical use form of the communication system of FIG. 12 is a flowchart for explaining article list display control corresponding to the embodiment of FIG. 11 by the wireless tag communication device of FIG. It is a figure explaining the structure of the RFID tag communication apparatus which is the other Example of this invention. It is a figure explaining the structure of the radio | wireless tag communication apparatus which is another Example of this invention. It is a figure explaining the other structure of the place tag which is a communication object of the wireless tag communication apparatus of FIG. It is an example of the frequency spectrum which shows the modulation frequency used for the modulation | alteration by the article tag of FIG. 3, and the place tag of FIG. 17 is a frequency spectrum showing a carrier wave and a sideband signal of a response wave when the interrogation wave transmitted from the RFID tag communication apparatus of FIG. 2 is modulated by the modulation frequency shown in FIG. It is a figure which shows the relationship between the main carrier wave used in the communication system of FIG. 1, and a response wave.

Explanation of symbols

10: RFID tag communication system 12, 62, 68: RFID tag communication device 14, 14 ': RFID tag (tag having management information)
16, 17: Wireless tag (tag having location information)
32: Bandpass filter (signal divider)
64: A / D converter 74: Antenna element 80: Directivity controller (transmission / reception phased array controller)

Claims (15)

A wireless tag communication device that transmits a transmission signal toward a predetermined wireless tag and receives a return signal returned from the wireless tag according to the transmission signal and communicates information with the wireless tag. There,
An RFID tag communication apparatus comprising: a signal dividing unit for dividing a received signal from the RFID tag into a plurality of signal areas.   The wireless tag communication device according to claim 1, wherein the signal dividing unit divides received signals from a plurality of types of wireless tags having different functions into a plurality of signal areas according to functions.   2. An A / D converter that converts a received signal from the wireless tag into a digital signal, wherein the signal dividing unit divides the received signal into a plurality of signal regions by digital signal processing. 2. RFID tag communication apparatus.   2. A reception phased array control unit that includes a plurality of antenna elements and controls a reception directivity by controlling a phase of each reception signal from the wireless tag received by the plurality of antenna elements. The RFID tag communication device according to any one of 1 to 3.   5. A transmission phased array control unit that includes a plurality of antenna elements and controls transmission directivity by controlling the phase of each transmission signal transmitted from the plurality of antenna elements. RFID tag communication device. A wireless tag communication system using the wireless tag communication device according to claim 1,
A wireless tag communication system, wherein information is communicated with a plurality of types of wireless tags having different signal areas.   The wireless tag communication system according to claim 6, wherein the plurality of types of wireless tags have different modulation frequencies.   The wireless tag communication system according to claim 6 or 7, wherein at least one wireless tag among the plurality of wireless tags performs information communication with the wireless tag communication device by frequency modulation.   9. The wireless tag communication system according to claim 8, wherein the wireless tag that performs frequency modulation performs frequency hopping that uses any one of a plurality of frequencies as a center frequency of the modulation frequency.   10. The wireless device according to claim 6, wherein at least one wireless tag among the plurality of wireless tags returns a response signal to all transmission commands transmitted from the wireless tag communication device. Tag communication system.   11. The wireless tag communication system according to claim 6, wherein at least one of the plurality of types of wireless tags is a semi-passive tag having a power supply device.   The RFID tag communication system according to any one of claims 6 to 11, wherein the RFID tag communication apparatus processes reception signals from a plurality of types of RFID tags received simultaneously with each other.   The wireless tag communication system according to any one of claims 6 to 12, wherein at least one of the plurality of types of wireless tags is a tag that is provided in a fixed position at a predetermined location and has location information indicating the location. .   The wireless tag communication system according to any one of claims 6 to 13, wherein at least one of the plurality of types of wireless tags is a tag attached to an article and having management information for managing the article.   The wireless tag communication device is the wireless tag communication device according to claim 4 or 5, wherein the plurality of types of wireless tags are arranged around the wireless tag communication device and received simultaneously from the plurality of types of wireless tags. 15. The RFID tag communication system according to claim 12, wherein the received signals are processed in association with each other.

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