JP2009098012A - Position detecting system of wireless tag, operation terminal, and wireless tag communication apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an accurate position of a wireless tag in detail by use of communication results from a plurality of wireless tag communication apparatuses. <P>SOLUTION: A position detecting system 1 of the wireless tag is disposed so as to be connected to each other by a network, and has a plurality of readers 2A, 2B for transmitting/receiving information to/from the wireless tag T within a coverage 20 from a reader antenna 5, and an operation terminal 3 for operating a plurality of the readers 2A, 2B. The readers 2A, 2B are disposed so that the coverage 20 partially overlap the other readers 2A, 2B. The operation terminal 3 combines information on the coverages 20 of at least two readers 2A, 2B, and calculates the position of the to-be-detected wireless tag T based on the communication results from the readers 2A, 2B for receiving a reply signal from the wireless tag T. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wireless tag position detection system, an operation terminal, and a wireless tag communication apparatus that detect the position of the wireless tag according to wireless communication with the wireless tag.

  2. Description of the Related Art RFID (Radio Frequency Identification) systems that transmit and receive information in a contactless manner (an electromagnetic coupling method using a coil, an electromagnetic induction method, a radio wave method, etc.) are known.

  As a wireless tag position detection system for detecting the position of such a wireless tag, for example, a system described in Patent Document 1 is known.

In this prior art, a plurality of wireless tags are scattered and arranged in a specific area. In addition, a plurality of RFID tag communication devices that can communicate with the RFID tag are arranged in the specific area, and each RFID tag communication device is connected to a server. When each wireless tag communication device is able to communicate with the wireless tag within its own communication range, the wireless tag communication device outputs identification information of the wireless tag to the server as needed along with its own location information. On the server side, the location information of the RFID tag communication device and the identification information of the RFID tag (which can communicate) are associated with each other to create a database and updated as needed. When a position detection request for a specific wireless tag is input to the server, the server searches the latest database using the identification information of the requested wireless tag as a key, and the corresponding wireless tag communication device (that is, the wireless tag communication device). The position information of the RFID tag communication device closest to the tag is output.
JP 2006-67086 A

  In the above prior art, it is assumed that one wireless tag and a communication area of one wireless tag communication device are associated with each other, and position information of the wireless tag communication device that can communicate with the wireless tag whose position is to be detected. Is used as position detection information of the wireless tag. However, since the communication area has a certain predetermined size, the position of one RFID tag communication device alone has a wireless tag in any part of the communication area of the RFID tag communication device in detail. I do n’t know. That is, the position of the wireless tag cannot be determined in detail with high accuracy.

  An object of the present invention is to provide a wireless tag position detection system capable of obtaining the position of a wireless tag in detail with high accuracy using communication results from a plurality of wireless tag communication apparatuses, and an operation terminal and a wireless device used therefor It is to provide a tag communication device.

  In order to achieve the above object, the first invention provides a plurality of RFID tag communication apparatuses that are arranged so as to be connected to each other in a network and that can respectively transmit and receive information to and from a RFID tag located in a communication area from an antenna, The RFID tag position detection system has an operation terminal capable of operating the RFID tag communication device, and each RFID tag communication device is arranged so that the communication area partially overlaps with another RFID tag communication device. The operation terminal synthesizes communication area information of at least two RFID tag communication devices based on a communication result from each RFID tag communication device that has acquired information from the RFID tag, and determines a position of the RFID tag. A position calculating means for calculating is provided.

  In the first invention of the present application, an operation terminal capable of operating a plurality of RFID tag communication apparatuses is provided. Each RFID tag communication device is arranged so that a part of the communication area (= communication area when transmission / reception can be performed with the RFID tag when there is a change in transmission power or antenna directivity) overlaps with others. ing. For this reason, when the wireless tag exists in the overlapping part, it becomes possible to communicate from the antennas of both wireless tag communication apparatuses.

  In the first invention of the present application, using this fact, each radio tag communication device is operated from the operation terminal to perform communication with the radio tag (in this case, the operation is only a so-called active operation). In other words, it includes a wide range of action operations such as simply collecting and acquiring communication results via a network). And when information can be acquired from the wireless tag by at least two wireless tag communication devices, the communication area information of these wireless tag communication devices (= as described above when the wireless tag communication can be performed) By combining (information indicating the communication area) (extracting and obtaining an overlapping part of the communication areas, which corresponds to “AND” in logical operation), the position where the wireless tag exists is calculated. can do.

  At this time, the position of the wireless tag can be obtained in detail with high accuracy by combining and narrowing down two or more pieces of communication area information. Further, in this case, since the position of the wireless tag can be detected simply by operating the wireless tag communication device from the terminal, there is no need to provide a server or the like for centrally managing a large number of wireless tag communication devices.

  According to a second aspect, in the first aspect, the wireless tag communication device includes communication region transmission means for transmitting communication region information from the antenna to the operation terminal during communication with the wireless tag, The position calculation means of the terminal synthesizes the communication area information from the communication area transmission means of the wireless tag communication apparatus that has acquired information from the wireless tag, and calculates the position of the wireless tag. To do.

  As a result, when the operation terminal does not know the communication area of each RFID tag communication device in advance, or when the transmission output from the antenna is variable or the directivity is variable, the communication of each RFID tag communication device Even if the area can vary, the communication area of each wireless tag communication device at the time of communication with the wireless tag can be reliably grasped by the operation terminal. As a result, the position of the wireless tag can be calculated by combining the communication area information.

  According to a third aspect of the present invention, in the first or second aspect of the invention, the operation terminal outputs a communication instruction signal to the wireless tag communication device so as to acquire information from the wireless tag to be communicated via wireless communication. Information acquisition means for acquiring information from the communication target wireless tag by wireless communication via the antenna based on the communication instruction signal from the communication instruction means; Communication result transmission means for transmitting to the operation terminal a communication result signal indicating whether or not information acquisition by the information acquisition means is possible, and the position calculation means of the operation terminal includes at least two RFID tag communication devices. The position of the wireless tag is calculated based on the communication result signal.

  Each wireless tag communication device is operated by a communication instruction signal from the communication instruction means of the operation terminal, the information acquisition means communicates with the wireless tag, and the communication result transmission means transmits a communication result signal. If the communication result signals of at least two RFID tag communication devices are information acquisition success, the position calculation means determines the communication area information of the RFID tag communication device that has acquired information successfully based on the communication result signals. By combining, the position where the wireless tag exists can be calculated.

  In a fourth aspect based on the third aspect, the RFID tag communication apparatus transmits position information storage means for storing position information of the RFID tag communication apparatus and transmission of the communication result signal from the communication result transmission means. In relation to this, the apparatus further comprises position information transmitting means for transmitting the position information stored and held in the position information storage means to the operation terminal.

  As a result, even when the position of each wireless tag communication device is not grasped in advance on the operation terminal side or when the position of each wireless tag communication device can change (due to rearrangement, etc.), The position of each RFID tag communication device at the time of communication can be reliably grasped by the operation terminal. As a result, it is possible to calculate the position of the wireless tag by combining the communication area information based on the position.

  In a fifth aspect based on the third aspect, the RFID tag communication apparatus is configured to transmit identification information storage means for storing and holding identification information of the RFID tag communication apparatus, and transmission of the communication result signal from the communication result transmission means. In relation to this, it comprises an identification information transmission means for transmitting the identification information stored and held in the identification information storage means to the operation terminal.

  When the identification information of the RFID tag communication device and the arrangement position corresponding to the identification information are associated in advance, the operation terminal sends the identification information from the identification information transmitting means (even if the position information is not directly acquired from each RFID tag communication device). By acquiring the identification information, the position of each wireless tag communication device can be grasped. As a result, it is possible to calculate the position of the wireless tag by combining the communication area information based on the position.

  According to a sixth invention, in the fourth or fifth invention, the communication instruction means of the operation terminal can sequentially output the communication instruction signals in a predetermined order to at least two of the RFID tag communication devices. And the position calculation means of the operation terminal is configured to output the RFID tag based on the communication result signals respectively transmitted from the at least two RFID tag communication apparatuses corresponding to the sequentially output communication instruction signals. The position is calculated.

  If a wireless tag exists in a portion where communication areas of at least two wireless tag communication apparatuses overlap, the position of the wireless tag is calculated in detail by combining the communication area information using the position calculation means. Can do. In the sixth invention of the present application, communication instruction signals can be sequentially output to each wireless tag communication device in a predetermined order. As a result, when the communication area is generated while sequentially switching the RFID tag communication devices, the communication area information can be calculated by calculating the position of the communication area information when the communication area capable of communicating with the RFID tag becomes the second or more. And the position of the wireless tag can be calculated.

  According to a seventh aspect of the present invention based on the sixth aspect, the communication instruction means of the operation terminal transmits, from the operation terminal, a wireless tag communication device relatively close to the operation terminal of the at least two wireless tag communication devices. The communication instruction signals are sequentially output in an order that is earlier than that of a relatively far RFID tag communication device.

  Accordingly, when the wireless tag communication devices are sequentially switched to generate the communication area, they can be generated in the order from the vicinity of the operation terminal to the distance. As a result, since the wireless tag can be detected at a relatively early time when it is near the operation terminal, the wireless tag search can be speeded up and made efficient.

  In an eighth aspect based on the seventh aspect, the communication instruction means of the operation terminal is different from the at least two RFID tag communication devices in the RFID tag communication device closest to the operation terminal. The communication instruction signal is output first with higher priority.

  As a result, the communication area can be generated first in the RFID tag communication device closest to the operation terminal, so that the RFID tag search can be surely speeded up when there is a radio tag in the immediate vicinity of the operation terminal. Can do.

  In a ninth aspect of the present invention based on the eighth aspect, the communication instruction unit of the operation terminal is configured such that the RFID tag communication device closest to the operation terminal succeeds in acquiring information from the RFID tag by the information acquisition unit. Then, the communication instruction signal is output to the RFID tag communication apparatus close to the operation terminal.

  When information can be acquired by the wireless tag communication device closest to the operation terminal for the first time, there is a high possibility that there is a wireless tag in the immediate vicinity of the operation terminal. Therefore, a communication area is generated by the RFID tag communication device next to the operation terminal next to the RFID tag communication device. Thereby, when the information can be acquired also by the next RFID tag communication apparatus, the communication area information of the two RFID tag communication apparatuses can be immediately combined to specify the position of the RFID tag. As a result, the wireless tag search can be surely speeded up.

  According to a tenth aspect of the present invention, the RFID tag communication apparatus according to any one of the sixth to ninth aspects of the present invention is arranged in the predetermined order in relation to the transmission of the communication result signal from the communication result transmitting unit. It has the following apparatus information transmission means which transmits the said position information or the said identification information of the RFID tag communication apparatus used as an order to the said operation terminal.

  Thereby, in order to quickly detect the RFID tag, which RFID tag communication device should generate the communication area next (from each RFID tag communication device to the one far from the operation terminal, or Information from a certain RFID tag communication device to an RFID tag communication device adjacent to the RFID tag communication device can be given to the operation terminal side according to a predetermined regularity. As a result, the operation terminal automatically switches the RFID tag communication device in accordance with the regularity, or operates the RFID tag communication device candidate to be activated next in accordance with the regularity on the operation terminal. To notify the operator.

  In an eleventh aspect of the present invention, in any one of the fourth to tenth aspects, the communication instruction unit of the operation terminal is configured to be capable of simultaneously outputting the communication instruction signal to at least two of the RFID tag communication devices. The position calculation means of the operation terminal calculates the position of the wireless tag based on the communication result signal respectively transmitted from the at least two wireless tag communication devices in response to the communication instruction signal output simultaneously. It is characterized by that.

  If a wireless tag exists in a portion where communication areas of at least two wireless tag communication apparatuses overlap, the position of the wireless tag is calculated in detail by combining the communication area information using the position calculation means. Can do. In the eleventh aspect of the present invention, communication instruction signals can be simultaneously output to at least two RFID tag communication apparatuses. As a result, these RFID tag communication devices can send and receive information to and from the RFID tag all at once, and if there are two or more RFID tag communication devices that can communicate with the RFID tag, the position of the communication area information is calculated. The position of the wireless tag can be calculated by combining by means.

  In a twelfth aspect based on the eleventh aspect, the communication instruction means of the operation terminal is different from the RFID tag communication apparatus closest to the operation terminal among the at least two RFID tag communication apparatuses. The communication instruction signal is output first with higher priority.

  Thus, prior to the simultaneous operation of the plurality of RFID tag communication apparatuses as described above, first, a communication area can be generated first in the RFID tag communication apparatus closest to the operation terminal. Therefore, when there is a wireless tag in the immediate vicinity of the operation terminal, it is possible to reliably speed up the wireless tag search. Further, when communication with the wireless tag can be performed in the first communication (since there is a high possibility that there is a wireless tag near the operation terminal), it is possible to stop performing the simultaneous operation wastefully.

  In a thirteenth aspect based on the twelfth aspect, the communication instruction means of the operation terminal is configured such that the wireless tag communication device closest to the operation terminal fails to acquire information from the wireless tag by the information acquisition means. The communication instruction signals are simultaneously output to the at least two RFID tag communication apparatuses.

  In addition, when communication with the wireless tag cannot be performed in the first communication, there is a high possibility that there is no wireless tag near the operation terminal (in other words, the wireless tag is far from the operation terminal). Accordingly, in the thirteenth invention of the present application, a plurality of wireless tag communication devices can transmit / receive information to / from the wireless tag all at once, thereby enabling a rapid search for the wireless tag.

  In order to achieve the above object, the fourteenth aspect of the present invention is arranged so as to be network-connectable to each other, arranged so that a communication area from the antenna partially overlaps with another RFID tag communication apparatus, and is located within the communication area. An operation terminal capable of operating a plurality of RFID tag communication devices capable of transmitting / receiving information to / from the RFID tag to communicate with the RFID tag communication device so as to acquire information from the RFID tag to be communicated via wireless communication A communication instruction means for outputting an instruction signal; and a position calculation means for calculating the position of the wireless tag by combining the communication area information of each wireless tag communication device that has acquired information from the wireless tag. To do.

  Each wireless tag communication device is operated by a communication instruction signal from the communication instruction means of the operation terminal, and information is acquired from the wireless tag. If the communication results of at least two RFID tag communication devices are information acquisition success, the position calculation means combines the communication area information of the RFID tag communication devices that have successfully acquired the information, so that the RFID tag Can be calculated.

  At this time, by combining and narrowing down two pieces of communication area information, the position of the wireless tag can be obtained in detail with high accuracy. Further, in this case, since the position of the wireless tag can be detected simply by operating the wireless tag communication device from the terminal, there is no need to provide a server or the like for centrally managing a large number of wireless tag communication devices.

  In a fifteenth aspect based on the fourteenth aspect, the communication instruction means prioritizes the RFID tag communication device closest to the operation terminal among the at least two RFID tag communication devices over other RFID tag communication devices. When the RFID tag communication device that first outputs the communication instruction signal and succeeds in obtaining information from the RFID tag by the information obtaining unit, the RFID tag that is next closest to the manipulation terminal The communication instruction signal is output to a communication device.

  As a result, the communication area can be generated first in the RFID tag communication device closest to the operation terminal. And when information can be acquired with this nearest RFID tag communication apparatus, there is a high possibility that there is a RFID tag in the immediate vicinity of the operation terminal. Therefore, a communication area is generated by the RFID tag communication device next to the operation terminal next to the RFID tag communication device. Thereby, when the information can be acquired also by the next RFID tag communication apparatus, the communication area information of the two RFID tag communication apparatuses can be immediately combined to specify the position of the RFID tag. As a result, the wireless tag search can be surely speeded up.

  In a sixteenth aspect based on the fifteenth aspect, the communication instructing unit is configured such that the at least 2 when the wireless tag communication device closest to the operation terminal fails to acquire information from the wireless tag by the information acquiring unit. The communication instruction signal is simultaneously output to two RFID tag communication apparatuses.

  When communication with the wireless tag cannot be performed in the first communication, there is a high possibility that there is no wireless tag near the operation terminal (in other words, the wireless tag is far from the operation terminal). Therefore, by searching and transmitting information to / from the wireless tag simultaneously for a plurality of wireless tag communication devices, it is possible to quickly search for the wireless tag.

  In order to achieve the above object, the seventeenth aspect of the invention is configured so that information can be transmitted to and received from a wireless tag located in a communication area from an antenna, and the communication area partially overlaps with another wireless tag communication apparatus. The wireless tag communication device is arranged to be connected to a network with the other wireless tag communication device, and based on the communication instruction signal from an operation terminal, the communication target is communicated by wireless communication via the antenna. It has an information acquisition means for acquiring information from the wireless tag, and a communication result transmission means for transmitting a communication result signal indicating whether or not the information acquisition means can acquire information to the operation terminal.

  In the seventeenth invention of the present application, the information acquisition means communicates with the wireless tag by the communication instruction signal of the operation terminal, and the communication result transmission means transmits the communication result signal to the operation terminal corresponding to the communication result. Thereby, when the communication result signal from at least two RFID tag communication apparatuses having such a configuration is information acquisition success, on the operation terminal side, communication area information of the RFID tag communication apparatus that has successfully acquired the information By combining, it is possible to calculate the position where the wireless tag exists.

  At this time, by combining and narrowing down two pieces of communication area information, the position of the wireless tag can be obtained in detail with high accuracy. Further, in this case, since the position of the wireless tag can be detected simply by operating the wireless tag communication device from the terminal, there is no need to provide a server or the like for centrally managing a large number of wireless tag communication devices.

  In an eighteenth aspect based on the seventeenth aspect, the position information storage means for storing and holding the position information of the RFID tag communication apparatus, and the position information related to transmission of the communication result signal from the communication result transmission means And a positional information transmitting unit that transmits the positional information stored and held in the storage unit to the operation terminal.

  Thereby, even when the position of the wireless tag communication device is not grasped in advance on the operation terminal side or when the position of the wireless tag communication device can change (due to rearrangement, etc.) The position of the RFID tag communication device can be ascertained with an operation terminal. As a result, it is possible to calculate the position of the wireless tag by combining the communication area information of each wireless tag communication apparatus with the position as a reference.

  In a nineteenth aspect based on the seventeenth aspect, the identification information storage means for storing and holding identification information of the RFID tag communication apparatus, and the identification information in relation to transmission of the communication result signal from the communication result transmission means And an identification information transmitting means for transmitting the identification information stored and held in the storage means to the operation terminal.

  When the identification information of the RFID tag communication apparatus and the corresponding arrangement position are associated in advance, the operation terminal identifies the identification information from the identification information transmitting means (even if the position information is not directly acquired from the RFID tag communication apparatus). By acquiring the information, the position of the wireless tag communication device can be grasped. As a result, it is possible to calculate the position of the wireless tag by combining the communication area information of each wireless tag communication apparatus with the position as a reference.

  A twentieth aspect of the present invention is the RFID tag communication apparatus according to the eighteenth or nineteenth aspect of the present invention, wherein the wireless tag communication apparatus is in the next order along a predetermined order in relation to transmission of the communication result signal from the communication result transmitting means. The apparatus further comprises a next device information transmitting means for transmitting the position information or the identification information to the operation terminal.

  Thereby, in order to quickly detect the RFID tag, which RFID tag communication device should generate the communication area next (from the RFID tag communication device close to the operation terminal to the RFID tag communication device far from the operation terminal) Alternatively, information from a certain RFID tag communication device to an RFID tag communication device adjacent to the RFID tag communication device can be given to the operation terminal side in accordance with a predetermined regularity. As a result, the operation terminal automatically switches the RFID tag communication device in accordance with the regularity, or operates the RFID tag communication device candidate to be activated next in accordance with the regularity on the operation terminal. To notify the operator.

  ADVANTAGE OF THE INVENTION According to this invention, the position of a wireless tag can be calculated | required accurately using the communication result by a some wireless tag communication apparatus.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The present embodiment is an example in which the wireless tag position detection system of the present invention is applied to searching for documents in an office, for example.

  FIG. 1 is an explanatory diagram conceptually showing an office room 100 in which the wireless tag position detection system 1 of the present embodiment is provided. In FIG. 1, twelve work desks 101 are installed in an office room 100 formed by one closed space in an arrangement in which three rows (rows: horizontal alignment) and four columns (columns: vertical alignment) are aligned. Has been. Each work desk 101 is provided with a bookcase and a drawer (not shown), and each can store a plurality of documents 102 or place it on the desk. A wireless tag T for management is affixed to each document 102.

  Each work desk 101 is provided with an operation terminal 3 and a terminal reader (wireless tag communication device) 2A connected in an arrangement close to the operation terminal 3. A plurality of independent readers (wireless tag communication devices) 2B (without corresponding operation terminals such as the operation terminal 3) are installed on a predetermined wall of the office 100. In the illustrated example, each terminal reader 2 </ b> A is arranged at the same position on each work desk 101. Further, three independent readers 2B are provided on each of the left and right walls in the figure and four on the lower wall in the figure, and are arranged in an aligned arrangement corresponding to the matrix arrangement of the terminal readers 2A. .

  All the terminal readers 2A and the independent readers 2B have the reader antennas 5 having the same configuration as will be described later. Communication is possible (details will be described later). And all the operation terminals 3 and all the independent reader | leaders 2B are connected so that transmission / reception of information is possible via the communication network NW.

  In this wireless tag position detection system 1, an operator (a person who sits at one work desk and uses an operation terminal) is affixed to a required document 102 with respect to the operation terminal used by the operator. The identification information of the wireless tag T (hereinafter referred to as a tag ID) is input, and an instruction is given to start searching for the current position of the required document 102. Thereby, each operation terminal 3 and each independent reader 2B mutually transmit and receive information, estimate the current position of the wireless tag T corresponding to the tag ID (current position of the required document), and display the operation terminal 3 To display. The “operation” at the operation terminal in the present embodiment is not limited to the so-called active operation as described above. In other words, the action operation in a broad sense, for example, the operation terminal 3 may simply collect and acquire the communication result via the communication network NW when the power is turned on.

  FIG. 2 is a system configuration diagram illustrating an outline of the wireless tag position detection system 1 of the present embodiment.

  In FIG. 2, as described above, the wireless tag position detection system 1 includes a plurality of operation terminals 3 each connected to a terminal reader 2A and a plurality of independent readers 2B connected by a communication network NW ( Note that the terminal reader 2A may also be directly connected to the communication network NW, similarly to the operation terminal 3. In the figure, only one operation terminal 3 and one terminal reader 2A and one independent reader 2B connected to the operation terminal 3 are shown in order to avoid the complexity of illustration.

  The operation terminal 3 is constituted by a general-purpose personal computer that is generally used. That is, the operation terminal 3 is input with instructions and information from a user, for example, a CPU 6, a non-volatile storage device 7 including a hard disk device or a flash memory, and storing various information, a memory 8 including, for example, a RAM or a ROM, and the like. Operation unit 9, a display unit 10 for displaying various information and messages, an interface 11 for controlling transmission and reception of control signals and information signals to the terminal reader 2A, and other operations via the communication network NW. And a network communication control unit 12 that controls transmission and reception of control signals and information signals with the terminal 3 and the independent reader 2B. The CPU 6 performs signal processing according to a program stored in advance in the ROM while using the temporary storage function of the RAM, thereby performing various controls of the entire operation terminal 3.

  The terminal reader 2 </ b> A includes a main body control unit 15 and a reader antenna (antenna) 5. The main body control unit 15 includes a CPU 16 and an RF communication control unit 17 that controls wireless communication with the wireless tag T via the memory 8, the interface 11, and the reader antenna 5 similar to the above.

  The independent reader 2 </ b> B has substantially the same configuration as the terminal reader 2 </ b> A, and includes a network communication control unit 12 instead of the interface 11. When the terminal reader 2A is also directly connected to the communication network NW as described above, the network communication control unit 12 is provided in the same manner as the independent reader 2B.

  In the present embodiment, a wired network using a cable or the like is assumed for the communication network NW. However, the present invention is not limited to this. For example, a wireless network having a frequency band and transmission / reception method different from that of the RF communication control unit 17 is used. Also good. Each operation terminal 3 and each reader 2A, 2B have mutual identification information (for example, a network address defined in the network, an IP address compliant with the TCP / IP protocol, a terminal ID for identifying each, Communication can be performed after mutually identifying (recognizing) a communication partner with a reader ID or the like. This identification information is stored in the memory 7 or the non-volatile storage device 7 in the operation terminal 3, and in the readers 2A and 2B, for example, the same as the memory 8 (or the non-volatile storage device 7 of the operation terminal 3). (It may be a non-volatile storage device) (identification information storage means).

  The wireless tag T includes a wireless tag circuit element To including a tag-side antenna 151 and an IC circuit unit 150. The RFID tag T is provided by, for example, attaching the RFID tag circuit element To on a substrate (not shown) to the document 202, attaching, bundling, etc. (the RFID tag circuit element To will be described later). Details).

  FIG. 3 is a functional block diagram showing the configurations of the CPU 16, the RF communication control unit 17, and the reader antenna 5 that are common to the terminal reader 2 </ b> A and the independent reader 2 </ b> B.

  In FIG. 3, the CPU 16 processes a signal read from the IC circuit unit 150 of the RFID circuit element To and reads information, and reads a tag ID for accessing the IC circuit unit 150 of the RFID circuit element To. A command (details will be described later) is generated.

  The RF communication control unit 17 accesses information (information including a tag ID) of the IC circuit unit 150 of the RFID circuit element To via the reader antenna 5. The RF communication control unit 17 inputs a transmission unit 212 that transmits a signal to the RFID circuit element To through the reader antenna 5 and a response wave from the RFID circuit element To that is received by the reader antenna 5. Receiving section 213 and transmission / reception separator 214.

  The transmission unit 212 is a block that generates an interrogation wave for accessing (reading in this example) the RFID tag information of the IC circuit unit 150 of the RFID circuit element To. That is, the transmission unit 212 includes a crystal oscillator 215A that generates a reference frequency, a PLL (Phase Locked Loop) 215B that generates a carrier wave of a predetermined frequency under the control of the CPU 16 based on the frequency generated by the crystal oscillator 215A, and A VCO (Voltage Controlled Oscillator) 215C and a transmission multiplication circuit 216 that modulates the generated carrier wave based on a signal supplied from the CPU 16 (in this example, amplitude modulation based on a “TX_ASK” signal from the CPU 16) In the case of amplitude modulation, an amplification factor variable amplifier or the like may be used, and the modulation wave modulated by the transmission multiplication circuit 216 is amplified (in this example, the amplification factor is determined by the “TX_PWR” signal from the CPU 16) ) Variable transmission amplifier 217. The generated carrier wave uses, for example, a UHF band, a microwave band, or a short wave band, and the output of the transmission amplifier 217 is transmitted to the reader antenna 5 via the transmission / reception separator 214 to be a RFID circuit element. It is supplied to the IC circuit section 150 of To. The interrogation wave is not limited to the signal (modulation wave) modulated as described above, and may be only a carrier wave.

  The receiving unit 213 multiplies and demodulates the response wave from the RFID circuit element To received by the reader antenna 5 and input via the transmission / reception separator 214 and the generated carrier wave. 218, a first bandpass filter 219 for extracting only a signal in a necessary band from the output of the reception first multiplication circuit 218, a reception first amplifier 221 for amplifying the output of the first bandpass filter 219, The first limiter 220 that further amplifies the output of the reception first amplifier 221 and converts it into a digital signal, the response wave from the RFID circuit element To received by the reader antenna unit 3, and the phase shift after being generated. A reception second multiplication circuit 222 that multiplies the carrier wave whose phase is delayed by 90 ° by the device 227, and a necessary band from the output of the reception second multiplication circuit 222. A second band pass filter 223 for extracting only the signal, a reception second amplifier 225 for amplifying the output of the second band pass filter 223, and further amplifying the output of the reception second amplifier 225 for conversion into a digital signal The second limiter 224 is provided. The signal “RXS-I” output from the first limiter 220 and the signal “RXS-Q” output from the second limiter 224 are input to the CPU 16 and processed.

  The outputs of the reception first amplifier 221 and the reception second amplifier 225 are also input to an RSSI (Received Signal Strength Indicator) circuit 226 as intensity detection means, and a signal “RSSI” indicating the intensity of these signals is input to the CPU 16. It is designed to be entered. In this way, each reader 2A, 2B demodulates the response wave from the RFID circuit element To by IQ orthogonal demodulation.

  At this time, each of the readers 2A and 2B transmits a tag ID read command for requesting the RFID tag circuit elements To of the plurality of RFID tags T existing in the communication area to emit tag IDs as response signals. . This tag ID read command is a command for confirming whether or not there is a RFID circuit element To corresponding to a specific tag ID among a plurality of RFID circuit elements To (in this example) Identification information (tag ID) of the RFID circuit element To to be confirmed is included. When this tag ID read command is transmitted from the RF communication control unit 17 via the reader antenna 5, only the RFID circuit element To corresponding to the tag ID included therein returns the same tag ID as a response signal. To do. In this way, when a tag ID read command including a tag ID to be specified is transmitted from each reader 2A, 2B and a response signal with the same tag ID can be received thereafter, each communication of the reader 2A, 2B is performed. The presence of the RFID circuit element To corresponding to the tag ID is detected in the area.

  FIG. 4 is a block diagram showing an example of a functional configuration of the RFID circuit element To provided in the RFID tag T.

  FIG. 4 is a functional block diagram showing a functional configuration of the RFID circuit element To provided in the RFID tag T. In FIG. 4, the RFID circuit element To is connected to the tag antenna 151 for transmitting and receiving signals without contact with the reader antennas 5 of the readers 2A and 2B as described above, and to the tag antenna 151. The IC circuit unit 150 is included.

  The IC circuit unit 150 rectifies the interrogation wave (signal including the tag ID read command) received by the tag side antenna 151, and accumulates and drives the energy of the interrogation wave rectified by the rectification unit 152. A power supply unit 153 for use as a power source, a clock extraction unit 154 that extracts a clock signal from the interrogation wave received by the tag antenna 151 and supplies the clock signal to the control unit 157, and a memory unit that can store a predetermined information signal 155, a modulation / demodulation unit 156 connected to the tag-side antenna 151, and the control unit for controlling the operation of the RFID circuit element To through the memory unit 155, the clock extraction unit 154, the modulation / demodulation unit 156, and the like. 157.

  The modulation / demodulation unit 156 demodulates the communication signal received from the tag side antenna 151 from the reader antenna 3 of the RFID tag information communication apparatus 1, modulates the return signal from the control unit 157, and 151 is transmitted as a response wave (a signal including a tag ID).

  The clock extraction unit 154 extracts a clock component from the received signal and extracts a clock to the control unit 157, and supplies a clock corresponding to the frequency of the clock component of the received signal to the control unit 157.

  The control unit 157 interprets the received signal demodulated by the modulation / demodulation unit 156, generates a return signal based on the information signal stored in the memory unit 155, and sends the return signal to the tag side by the modulation / demodulation unit 156. Basic control such as control returned from the antenna 151 is executed.

  Here, the most significant feature of the wireless tag position detection system 1 of the present embodiment is that each reader 2A, 2B and the other readers 2A, 2B respectively change from each other to the communication area (= transmission power and antenna directivity from time to time). In this case, each of the at least two readers 2A and 2B that can detect the tag ID of the wireless tag T to be detected is arranged so as to partially overlap the communication area when the wireless tag T can be transmitted and received. The position of the wireless tag T is calculated by combining the communication areas. Hereinafter, the details will be sequentially described.

  First, the arrangement relationship of the communication areas of the readers 2A and 2B will be described. FIG. 5 is a diagram illustrating an example of an arrangement relationship between the readers 2A and 2B and their communication areas. Note that FIG. 5 associates the arrangement positions of the offices 100 and the work desk 101 shown in FIG. 1 with the readers 2A and 2B. In the figure, only the work desk 101, the circle symbol indicating the installation position of each reader 2A, 2B, and the communication area of each reader 2A, 2B are illustrated. In order to avoid complications, the communication areas of some readers 2A and 2B are not shown.

  The communication area 20 (the range indicated by the broken line in the figure) of each reader 2A, 2B is a finite area extending from the reader antenna 5 as a base point, and has a shape and size determined by its directivity and output power (so-called antenna power). (Communication distance). In the example shown in FIG. 5, the reader antennas 5 of the readers 2 </ b> A and 2 </ b> B are configured by dipole antennas (not shown), both of which are horizontal and the longitudinal direction is parallel to the horizontal direction in the drawing. It is arranged as follows. Each reader 2A, 2B performs wireless communication with the same output power. For this reason, the communication area 20 of each reader 2A, 2B is formed in the same size with a shape sandwiched by two ellipses in the vertical direction in the figure centering on each reader 2A, 2B as seen in the plan view shown. ing. Then, each operation terminal 3 associates information (communication area information) on the arrangement, shape, and size of these communication areas 20 corresponding to each reader 2A, 2B (for example, corresponding to the identification information of each reader 2A, 2B). ) Stored in advance in the nonvolatile storage device 7 or the like.

  Since the readers 2A and 2B are arranged at intervals shorter than the size of the communication area 20, the communication areas 20 are partially overlapped between the readers 2A and 2B that are close to each other. It is an arrangement relationship. For example, for the communication area 20 of the terminal reader 2A at the position indicated by a black circle “●” in the figure, seven readers 2A, 2B surrounding the terminal reader 2A (indicated by a double circle “図” in the figure) It can be seen that all of the communication areas 20) overlap in a sufficiently wide area.

  By the way, in this embodiment, the arrangement | positioning coordinate of each reader | leader 2A, 2B in the office room 100 is preset as a coordinate. FIG. 6 is a diagram illustrating an example of the coordinate setting of the arrangement positions of the readers 2 </ b> A and 2 </ b> B in the office room 100.

  In FIG. 6, in this embodiment, a position number (which may be used as the above-described reader ID) is set for the arrangement positions of the readers 2A and 2B. In this example, the position number is set by serial numbers (P1 to P22) for all readers 2A and 2B (22), and the arrangement coordinates are set based on the XY coordinate system set in the office room 100. Has been.

  The basic unit of the XY coordinate system may be an actual size (mm or cm), or may be a virtual unit set for convenience in calculation. In the example shown in the figure, the upper left corner point in the figure is 0, the X direction corresponds to the horizontal direction in the figure, and the Y direction corresponds to the vertical direction in the figure. And the arrangement position of each reader | leader 2A, 2B (each position number P1-P22) is represented by the arrangement | positioning coordinate based on this XY coordinate system. For example, the arrangement position of the independent reader 2B having the position number P1 can be represented by (PX1, PY1).

  In the present embodiment, as will be described later, the position detection of the target wireless tag T by the readers 2A and 2B is executed in a predetermined order. In this example, the readers 2 </ b> A and 2 </ b> B sequentially perform detection in the order closer to each operation terminal 3. For this reason, the readers 2A and 2B are recorded in the operation terminal 3 as a list in the order close to the operation terminal 3 (proximity order reader list).

  FIG. 7 is a diagram conceptually illustrating an example of a proximity order reader list that is stored in each operation terminal 3 and stores various information about the readers 2A and 2B. The proximity reader list is recorded and held in the nonvolatile storage device 7 of each operation terminal 3. The example shown in the figure is stored in the operation terminal 3 directly connected to the terminal reader 2A at the arrangement position P6 shown in FIG.

  As shown in FIG. 7, this proximity reader list includes a position number of each reader 2A, 2B, an X coordinate and a Y coordinate representing the arrangement coordinates, and identification information of each reader 2A, 2B (the network address described above). , IP address, reader ID, etc.) are stored in the form of correlation information associated with reference numbers represented by serial numbers from 1 to 22. This reference number refers to the terminal reader 2A directly connected to the operation terminal 3 storing the proximity order reader list (hereinafter referred to as the own reader 2A as appropriate; in this example, the terminal reader 2A at the arrangement position P6). The number assigned to the first “1” and then assigned in the order of the readers 2A and 2B arranged in a relatively close order with the operation terminal 3 as a base point, is installed in the office 100. All 22 readers 2A and 2B are assigned.

  The first reader whose reference number is “1” is the terminal reader 2A to which the operation terminal 3 is connected via the interface 11, and therefore the item content of the identification information is omitted (not omitted). May be described). Further, when an IP address or a network address is used as identification information in the terminal reader 2A, such as the terminal reader 2A at the arrangement position P5 (corresponding to the reference number 4 in the illustrated example), the corresponding operation terminal 3 is used. May be stored as identification information of the terminal reader 2A.

  FIG. 8 is a flowchart showing a control procedure executed by the CPU 6 of each operation terminal 3. Each operation terminal 3 performs the same flow control procedure. Further, a processing request signal, a processing permission signal, a processing refusal signal, and a start report signal, which will be described later, are finally transmitted and received between each operation terminal 3 and each reader 2A, 2B via the communication network NW (hereinafter, referred to as “the processing request signal”, “processing permission signal”, “processing rejection signal”). The same).

  In FIG. 8, for example, this flow is started after the power is turned on (START position). First, in step S <b> 5, it is determined whether an operation for requesting the position detection of the wireless tag T attached to the required document 202 has been performed by the operator through an input operation on the operation unit 9. The input operation here is an input operation including the tag ID of the wireless tag T whose position is to be detected. Although not particularly shown, correlation information that associates the document name of each document 202 with the tag ID of the wireless tag T attached to each document 202 (for example, a nonvolatile storage device 7 or a server connected to a network separately) B) It may be stored in the form of a table or database. In this case, the operator inputs a document name or the like of the required document 202. Based on this, the corresponding tag ID is obtained from the table or database.

  If an input operation is performed by the operator, the determination is satisfied, and after performing tag position detection processing (details will be described later) in step S100, the process proceeds to step S15. On the other hand, if no input operation has been performed, the determination is not satisfied, and the routine goes directly to step S15.

  In step S15, it is determined whether an operation for ending the current process has been performed by the operator (via an input operation of the operation unit 9). If the end operation has not been performed, the determination is not satisfied, and the process returns to step S5 and the same procedure is repeated. On the other hand, when the end operation is performed, the determination is satisfied, and this flow is ended.

  FIG. 9 is a flowchart showing a detailed procedure of the tag position detection process executed in step S100 in FIG.

  In FIG. 9, first, in step S105, the value of the variable n corresponding to the reference number in the proximity order reader list is initialized to 1, and the process proceeds to the next step S110.

  In step S110, the identification information corresponding to the n-th readers 2A and 2B closest to the operation terminal 3 including the n-th reader 2A and 2B in the reference number order in the proximity order reader list, that is, the own reader 2A (first) is approached. Obtain from the forward reader list.

  Next, the process proceeds to step S115, and a tag detection request signal (communication instruction signal) is transmitted to the readers 2A and 2B corresponding to the identification information acquired in step S110 (communication instruction means). The tag detection request signal includes the tag ID (the tag ID of the wireless tag T attached to the necessary document 202) input in step S5 in the flow of FIG.

  Next, the process proceeds to step S120, where a tag detection result signal as a return signal is received from the readers 2A and 2B that transmitted the tag detection request signal in step S115 (see step S215 and step S220 in FIG. 10 described later). The included detection results are stored. The tag detection result signal includes the identification information of the readers 2A and 2B and additional information described later (described later).

  Next, the process proceeds to step S125, and based on the detection result stored in step S120, it is determined whether or not two tag detection result signals having contents indicating that the detection target wireless tag T has been detected so far have been received. . If two tag detection result signals that have been detected are received, the determination is satisfied, that is, it is considered that the position of the detection target wireless tag T can be estimated at this point, and the process proceeds to step S130.

  In step S130, the detection results of the two tag detection result signals indicating that the detection target RFID tag T has been detected are combined (detailed in FIG. 11 described later), and the current position of the detection target RFID tag T is obtained. (Position calculation means), the estimation result is displayed on the display unit 10 (see FIG. 12 described later), and this flow is terminated.

  On the other hand, in the determination in step S125, if two tag detection result signals indicating that the detection target wireless tag T has been detected have not been received yet, the determination is not satisfied, and the process proceeds to step S135, which includes the own reader 2A. It is determined whether tag detection result signals have been received from all readers 2A and 2B (22 in this example). If it has not been received from all the readers 2A and 2B, the determination is not satisfied, and after the value of the variable n is incremented by 1 in step S140, the process returns to step S110 and the same procedure is repeated.

  On the other hand, when the tag detection result signals are received from all the readers 2A and 2B, the determination is satisfied, that is, the positions of the RFID tags T to be detected although the RFID tags T are detected by all the readers 2A and 2B. It is considered that the two detection results necessary for estimating the value cannot be obtained, and the process proceeds to step S141.

  In step S141, based on the detection result stored in step S120, it is determined whether one tag detection result signal having the content that the detection target wireless tag T has been detected so far has been received. If none of the tag detection result signals that can be detected have been received, the determination at step S141 is not satisfied, and the routine goes to step S145. After displaying that the position detection has failed on the display unit 10 in step S145, this flow is ended.

  On the other hand, if one tag detection result signal that can be detected is received in step S141, the determination is satisfied, and the routine goes to step S143. In step S143, the detection result of the tag detection result signal from each reader 2A, 2B and additional information included in the tag detection result signal (for example, communication directivity and output power value of each reader) are used. Thus, the approximate current position of the detection target RFID tag T is roughly estimated, the result is displayed on the display unit 10, and this flow is terminated.

  FIG. 10 is a flowchart showing a control procedure executed in each reader 2A, 2B.

  In FIG. 10, first, in step S200, it is determined whether a tag detection request signal has been received from the operation terminal 3 via the communication network NW (or via the interfaces 11 and 11). This tag detection request signal is detected in the communication area 20 of the readers 2A and 2B that has received the tag detection request, and the detection result of the RFID tag T (included in the tag detection request signal) is returned. Is a control signal for requesting. If the tag detection request signal has not been received, the determination is not satisfied, and a loop is waited until reception. If the tag detection request signal is received, the determination is satisfied, and the routine goes to Step S205.

  In step S205, a control signal is output to the transmission unit 212 of the RF communication control unit 17, and a tag ID read command is transmitted from the reader antenna 5. Accordingly, the tag detection received via the communication network NW in step S10 in the flow of FIG. 8 for all the wireless tags T existing in the communication area 20 formed with the reader antenna 5 of the reader 2A as a base point. A tag ID read command including the tag ID (the tag ID of the detection target wireless tag T) included in the request signal is transmitted (information acquisition means). In this way, when the RFID tag T to be detected exists in the communication area 20 of the readers 2A and 2B, a reply signal (reply signal) including the tag ID is received via the reader antenna 5. If it does not exist, nothing is received.

  Next, the process proceeds to step S210, where it is determined whether a reply signal is received. If the reply signal is received, the determination is satisfied, and the process proceeds to the next step S215. In step S215, a tag detection result signal (communication) including a detection result indicating that the wireless tag T has been successfully detected and the identification information of the readers 2A and 2B is transmitted to the operation terminal 3 that is a transmission source of the tag detection request signal. (Result signal) is transmitted via the communication network NW (or the interfaces 11, 11) (communication result transmitting means, identification information transmitting means), and this flow is terminated.

  On the other hand, if the reply signal is not received in the determination in step S210, the determination is not satisfied and the process proceeds to step S220. In step S220, the tag detection result signal including the detection result indicating that the RFID tag T to be detected cannot be detected and the identification information of the readers 2A and 2B is detected with respect to the operation terminal 3 that is the transmission source of the tag detection request signal. (Communication result signal) is transmitted via the communication network NW (or the interfaces 11 and 11) (communication result transmission means, identification information transmission means), and this flow is terminated.

  FIG. 11 is a diagram schematically showing an example of a concept of estimating the current position of the detection target RFID tag T by combining the detection results of the tag detection result signals. FIG. 11, FIG. 5, and FIG. 6 is a diagram corresponding to FIG.

  FIG. 11 shows a case where the tag position detection process is performed in the operation terminal 3 connected to the terminal reader 2A at the arrangement position P6 in this example. In this case, the wireless tag T to be detected is detected by the own reader 2A (terminal reader 2A at the arrangement position P6; black circle in the figure), and is not detected by the independent reader 2B at the arrangement positions P3 and P7, but the arrangement position P5. The terminal reader 2A detects and terminates (for the order of the readers 2A and 2B to be detected, refer to the proximity order reader list in FIG. 7). In this case, the current position of the detection target RFID tag T (the position indicated by “x” in the figure) is an area where the communication area 20 of the reader 2A overlaps the communication area 20 of the terminal reader 2A at the arrangement position P5. (In detail, it is estimated that the communication area 20 of the independent reader 2B at the arrangement position P3 and the communication area 20 of the independent reader 2B at the arrangement position P7 are further excluded). That is, “synthesis” in the present embodiment is to obtain and extract and obtain an overlapping portion between communication areas, and corresponds to “AND” in a logical operation. As described above, in this example, since each operation terminal 3 stores information related to the communication area 20 of each reader 2A, 2B in advance, the above estimation is performed.

  In the procedure of step S130 in the flow of FIG. 9 described above, the range in which the RFID tag T to be detected may exist is estimated by combining the detection results as described above (such as duplication of the communication area 20 depending on whether detection is possible). calculate. Then, the estimated range is displayed on the display unit 10 as an approximately elliptical region as shown in FIG. 12 (corresponding to FIGS. 1, 5, 6, and 11 above), for example.

  Note that a technique other than the above may be used as a technique for synthesizing detection results and subsequent display techniques. For example, the midpoint of the line segment connecting the placement positions (P5 and P6) of the two readers 2A and 2B that can detect the detection target wireless tag T is displayed as the estimated presence position of the detection target wireless tag T. A predetermined range from the point may be displayed as an estimated existence range of the wireless tag T by a circle or an ellipse. Furthermore, when the detection results of three or more readers 2A and 2B are used, the center of gravity of a polygon formed by connecting the respective arrangement positions may be displayed as the estimated presence position of the detection target RFID tag T. . In addition, since the probability of communication at the boundary between communication areas is 50%, in the synthesis of a plurality of detection results as described above, an operation is performed in consideration of the communication probability of the result of a plurality of communication trials. May be added.

  As described above, in the present embodiment, each reader 2A, 2B is arranged so that a part of the communication area 20 overlaps the other, and the wireless tag T exists in the overlapping part. If it is, communication is possible from the reader antennas 5 of both readers 2A and 2B. In the present embodiment, using this fact, the reader 2A and 2B are operated from the operation terminal 3 to communicate with the wireless tag T. When information can be acquired from the wireless tag T by at least two readers 2A and 2B, information on the communication areas 20 of the readers 2A and 2B is synthesized (in the example of this embodiment, the communication areas 20 are geometrically connected to each other). The position where the wireless tag T is present can be calculated (see FIG. 12). At this time, since the information related to the two communication areas 20 is combined and narrowed down, the position of the wireless tag T can be obtained with high accuracy and detail (rather than simply from the communication area 20 of one reader that can communicate). Can do. Further, as described above, the position of the wireless tag T can be detected simply by operating the readers 2A and 2B from the operation terminal 3, and there is no need to provide a server or the like for centrally managing many readers 2A and 2B. There is also an effect. It should be noted that at least one reader 2A, 2B also has such a server function, and the communication results of a large number of readers 2A, 2B may be acquired via a network for calculation.

  In this embodiment, in particular, the operation terminal 3 stores information related to the communication area 20 of each reader 2A, 2B in the nonvolatile storage device 7 of each operation terminal 3, and each reader 2A, 2B has its identification information. Is retained. As a result, the operation terminal 3 acquires the identification information from each of the readers 2A and 2B (step S120 in FIG. 9), so that each reader 2A and 2B (even if the position information is not directly acquired from each reader 2A and 2B). The position of can be grasped. As a result, the information on the communication area 20 can be synthesized with the grasped position as a reference, and the position of the wireless tag T can be obtained.

  In this embodiment, in particular, tag detection request signals are sequentially output in order from the readers 2A and 2B that are relatively close to the operation terminal 3 used by the operator along the proximity order reader list (see FIG. 7). ). Thus, when the communication area 20 is generated by sequentially switching the readers 2A and 2B, they can be generated in the order from near to far from the operation terminal 3. In general, it is highly likely that the document 202 required by the operator has been stored in the vicinity of the operator himself until recently. By sequentially searching from near to far as described above, the wireless tag T can be detected relatively early when the operator is near the operation terminal 3 used. Thus, it is possible to speed up and improve the efficiency of searching for a wireless tag.

  Specifically, it is as follows. That is, the RFID tag T is located in the immediate vicinity of the operation terminal 3 by first generating the communication area 20 with the reader (own reader 2A) closest to the operation terminal 3 used by the operator first. In this case, it is possible to reliably speed up the search for the wireless tag. In particular, when the reply signal can be received by the reader 2A closest to the operation terminal 3 for the first time, there is a high possibility that the detection target wireless tag T is in the immediate vicinity of the operation terminal 3. Therefore, the communication area 20 is generated by the readers 2A and 2B closest to the operation terminal 3 next to the own reader 2A. As a result, when the next reader 2A, 2B can also receive the reply signal, it immediately synthesizes the information related to the communication area 20 of the two readers 2A, 2B and specifies the position of the detection target RFID tag T. can do. As a result, the wireless tag search can be surely speeded up.

  In the above embodiment, information related to the communication area 20 of each reader 2A, 2B is stored in the non-volatile storage device 7 of each operation terminal 3, but the present invention is not limited to this. That is, for example, each reader 2A, 2B is provided with a non-volatile storage device and the like, and information related to the communication area 20 of the reader 2A, 2B is stored in the reader 2A, 2B. The tag detection result signal to be transmitted may include information related to the communication area 20 of the readers 2A and 2B and be transmitted to the operation terminal 3 (communication area transmission means). In this way (unlike the above), when the operation terminal 3 does not grasp the communication area 20 of each reader 2A, 2B in advance, the transmission output from the reader antenna 5 is variable, or the directivity is variable. Thus, even if the communication area 20 of each reader 2A, 2B can be changed, the communication area 20 of each reader 2A, 2B at the time of communication with the wireless tag T can be reliably grasped by the operation terminal 3. . As a result, the position of the wireless tag T can be calculated by synthesizing information about the communication area 20.

  Further, when the communication area information is obtained from the readers 2A and 2B as described above, the identification information is not sent from the readers 2A and 2B together with the tag detection result to the terminal 3 as described above. The position information of each reader 2A, 2B may be sent to the terminal 3 together with the tag detection result (= position information transmission means. This position information is stored in the position information storage means such as the memory 18 as well as the identification information. Keep it stored). As the position information, for example, the arrangement coordinates of the readers 2A and 2B in the coordinate system as described above with reference to FIG. 6 can be used. In this case, based on the arrangement coordinates of the readers 2A and 2B, as described above, the midpoint of the line segment connecting the arrangement positions of the two readers 2A and 2B that can detect the wireless tag T is set as the detection target wireless. The estimated presence position of the tag T may be displayed on the coordinate axis, or a range of a predetermined diameter from the midpoint may be displayed on the coordinate axis as the estimated existence range of the wireless tag T. The same applies to the case where the detection results of three or more readers 2A and 2B are used.

The present invention is not limited to the above, and various modifications can be made without departing from the spirit and technical idea of the present invention. Hereinafter, such modifications will be described in order.
(1) When the order of readers that transmit tag detection request signals is acquired from the reader In the above embodiment, the order of the readers 2A and 2B that transmit tag detection request signals from the operation terminal 3 is stored in the nonvolatile storage of the operation terminal 3. Although the order of description in the proximity order reader list stored in the device 7 or the like is followed, the present invention is not limited to this. That is, for example, link information (including the identification information) specifying the readers 2A and 2B that transmit the tag detection request signal next may be acquired from the readers 2A and 2B that have received the tag detection result signal.

  FIG. 13 is a flowchart showing the control procedure of the tag position detection process executed in the operation terminal 3 of this modification, and corresponds to FIG. 9 in the above embodiment.

  In the flow of FIG. 13, steps S115A and S120A are newly provided in place of step S105 of the flow of FIG. Further, the difference is that instead of Step S110, Step S115, and Step S120, Step S110A, Step S115B, and Step S120B corresponding to these are provided.

  In FIG. 13, first, in step S115A corresponding to step S115, a tag detection request signal (communication instruction signal) is transmitted to the reader 2A as in step S115 (communication instruction means). This tag detection request signal includes the tag ID (the tag ID of the wireless tag T attached to the necessary document 202) as described above.

  Thereafter, the process proceeds to step S120A corresponding to step S120, and the tag detection result signal as a reply signal is received from the reader 2A that transmitted the tag detection request signal in step S115A (see steps S215 and S220 described above). , The detection results included therein are stored. The tag detection result signal also includes the identification information of the reader 2A. As a feature of this modification, link information specifying the readers 2A and 2B to which the tag detection request signal is to be transmitted next is also included in the tag detection result signal. Note that this link information is information stored in advance in a nonvolatile storage device or the like provided in each reader 2A, 2B of this modification, and in the normal case, the other readers 2A, 2A, 2B arranged adjacent to each other The content specifies 2B.

  Then, the process proceeds to step S110A corresponding to step S110, and identification information corresponding to the next-order readers 2A and 2B is acquired from the latest link information acquired at that time.

  Thereafter, the process proceeds to step S115B, and similarly to step S115A, a tag detection request signal (communication instruction signal) is transmitted to the readers 2A and 2B that have acquired the identification information in step S110A (communication instruction means) in the same manner as described above. This tag detection request signal includes the tag ID as described above.

  In step S120B, as in step S120A, the tag detection result signal as a return signal is received from the readers 2A and 2B that transmitted the tag detection request signal in step S115B (see steps S215 and S220 described above). , The detection results included therein are stored. As described above, the tag detection result signal includes the identification information of the readers 2A and 2B, and link information that specifies the readers 2A and 2B to which the tag detection request signal is to be transmitted next.

  Thereafter, Step S125, Step S130, Step S135, Step S141, Step S143, and Step S145 are the same as those in FIG. 9 and thus will not be described (however, if the determination in Step S135 is not satisfied, the description is directly made. (Return to step S110A).

  The control procedure executed by the readers 2A and 2B in the present modification is substantially the same as that shown in FIG. However, when the tag detection result signal is transmitted in step S215 and step S220, the link information stored in the readers 2A and 2B is also included in the tag detection result signal and transmitted (= next device information transmission means).

In this modified example configured as described above, in order to quickly detect the wireless tag T, which reader 2A, 2B should generate the communication area 20 next (of the operation terminal 3 of each reader) It is possible to give information in accordance with a predetermined regularity to the operation terminal 3 side, from near to far, or from a reader 2A, 2B to a reader 2A, 2B adjacent to it. As a result, the operation terminal 3 automatically switches the readers 2A and 2B to operate in accordance with the regularity, or selects candidates for the readers 2A and 2B to be activated next in accordance with the regularity at the operation terminal 3. It can be displayed and notified to the operator.
(2) When transmitting tag detection request signals to all readers simultaneously In the above embodiment, a predetermined number (2 in the example of the above embodiment) of tag detection result signals that are able to detect the wireless tag T to be detected. (Ii) Although the transmission of the tag detection request signal was stopped when it was received, the present invention is not limited to this. For example, the tag detection request signal may be transmitted to all the readers 2A and 2B all at once from the beginning.

  FIG. 14 is a flowchart showing the control procedure of the tag position detection process executed in this modification, and corresponds to FIG. 9 in the above embodiment and FIG. 13 in the modification of (1) above.

  In FIG. 14, first, in step S115C corresponding to step S115 or step S115A, the tag detection request signal (communication instruction signal) is transmitted to all readers 2A and 2B including the reader 2A (so-called broadcast communication) in the same manner as described above. ) Is transmitted (communication instruction means). This tag detection request signal includes the tag ID (the tag ID of the wireless tag T attached to the necessary document 202) as described above.

  Next, the process proceeds to step S120C corresponding to step S120 or step S120A, and the tag detection result signal as a return signal is received from the readers 2A and 2B that transmitted the tag detection request signal in step S115C, and the detections included therein Memorize the results. The tag detection result signal also includes the identification information of each reader 2A, 2B.

  In step S123, it is determined whether the tag detection result signal has been received from all readers 2A and 2B including the reader 2A. If there are other readers 2A and 2B that have not yet received the tag detection result signal, the determination is not satisfied, and the process returns to step S120C to repeat reception. On the other hand, when tag detection result signals are received from all the readers 2A and 2B, the determination is satisfied, and the routine goes to the next Step S125C.

  In step S125C, whether or not two or more tag detection result signals having contents indicating that the detection target RFID tag T can be detected based on the detection results from all the readers 2A and 2B stored in step S120C are received. Determine. When two or more tag detection result signals that have been detected are received, the determination is satisfied, that is, it is considered that the position of the detection target wireless tag T can be estimated, and the process proceeds to step S130. On the other hand, if the number of tag detection result signals that can be detected is less than 2, the determination is not satisfied, that is, it is considered that the position of the detection target wireless tag T cannot be estimated, and the process proceeds to step S141. Since the subsequent steps are the same as those in FIGS. 9 and 13, the description thereof is omitted.

  Also in this modified example configured as described above, the same effect as in the above embodiment is obtained. That is, a tag detection request signal is simultaneously output to all readers 2A and 2B, and all readers 2A and 2B are simultaneously transmitted to and received information from the wireless tag T. If there are two or more 2A and 2B, the information on the communication area 20 can be synthesized and the position of the detection target wireless tag T can be calculated.

  In the above description, all the readers 2A and 2B perform communication (information reading) to the wireless tag T at the same time in step S115C, but the present invention is not limited to this. That is, first, information reading is attempted only for the own reader 2A corresponding to the operation terminal 3, and thereafter, communication (information reading) to the wireless tag T is performed simultaneously for all readers 2A, 2B other than the own reader 2A. May be. Thus, prior to simultaneous operation of the plurality of readers 2A, 2B, first, the communication area 20 is first generated by the readers 2A, 2B, 2B closest to the operation terminal 3, so that When there is a wireless tag T to be detected, the wireless tag search can be surely speeded up. In addition, when communication with the wireless tag T can be performed in the first communication (since there is a high possibility that the wireless tag T is near the operation terminal 3), it is possible to stop performing the simultaneous operation wastefully. .

  Further, only when the own reader 2A closest to the operation terminal 3 fails to receive a reply signal from the detection target wireless tag T, the tag detection request is sent to all the other readers 2A and 2B other than the own reader 2A. You may make it output a signal all at once. That is, when communication with the RFID tag T to be detected cannot be performed by communication by the first reader 2A, there is no RFID tag T to be detected near the operation terminal 3 used by the operator (in other words, the detection object is detected). The wireless tag T is far away from the operation terminal 3). Therefore, by searching all of the readers 2A, 2B other than the reader 2A simultaneously with information transmission / reception with the RFID tag T, the RFID tag T can be searched quickly.

  In addition to those already described above, the methods according to the above-described embodiments and modifications may be used in appropriate combination.

  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 showing an example at the time of applying the position detection system of the wireless tag of embodiment of this invention to the search of the document in an office. It is a system configuration figure showing the outline of the position detection system of a wireless tag. It is a functional block diagram showing the detailed structure of CPU, RF communication control part, and a reader antenna in each reader. It is a block diagram showing an example of a functional structure of the RFID circuit element with which the RFID tag was equipped. It is a figure showing an example of the arrangement | positioning relationship between each reader | leader and its communication area. It is a figure showing an example of the coordinate setting of the arrangement position of each reader in an office. It is a figure which represents notionally an example of the proximity | contact order leader list which each operation terminal memorize | stores. It is a flowchart showing the control procedure performed by CPU of each operation terminal. It is a flowchart showing the detailed procedure of step S100 in FIG. It is a flowchart showing the control procedure performed in each reader. It is a figure which represents typically an example of the concept which synthesize | combines the detection result of a tag detection result signal, and estimates the present position of the radio | wireless tag of a detection target. It is a figure showing an example which displayed the estimation result of the present position of the radio tag of detection object on a display part. It is a flowchart showing the control procedure of the tag position detection process performed in the modification which acquires link information from a reader. It is a flowchart showing the control procedure of the tag position detection process performed in the modification which transmits a tag detection request signal to all the readers simultaneously.

Explanation of symbols

1 Wireless Tag Position Detection System 2A Terminal Reader (Wireless Tag Communication Device)
2B Independent reader (wireless tag communication device)
3 Operation terminal 5 Reader antenna (antenna)
7 Non-volatile storage device 8 Memory 9 Operation unit 10 Display unit 12 Network control unit 15 Main body control unit 20 Communication area NW Communication network (network)
T wireless tag

Claims (20)

A plurality of wireless tag communication devices that are arranged so as to be connected to each other and capable of transmitting and receiving information to and from wireless tags located in a communication area from the antenna
An RFID tag position detection system having an operation terminal capable of operating the plurality of RFID tag communication devices,
Each RFID tag communication device
The communication area is arranged so as to partially overlap with other RFID tag communication devices,
The operation terminal is
And a position calculating unit that calculates the position of the wireless tag by combining communication area information of at least two wireless tag communication apparatuses based on a communication result from each of the wireless tag communication apparatuses that can acquire information from the wireless tag. A wireless tag position detection system characterized by the above. The wireless tag position detection system according to claim 1,
The wireless tag communication device includes:
Communication area transmission means for transmitting communication area information from the antenna to the operation terminal during communication with the wireless tag,
The position calculation means of the operation terminal is
A wireless tag position detection system comprising: combining the communication area information from the communication area transmission unit of the wireless tag communication apparatus that has acquired information from the wireless tag, and calculating the position of the wireless tag. The wireless tag position detection system according to claim 1 or 2,
The operation terminal is
Communication instruction means for outputting a communication instruction signal to the wireless tag communication device so as to obtain information from the wireless tag to be communicated via wireless communication;
The wireless tag communication device includes:
Based on the communication instruction signal from the communication instruction means, information acquisition means for acquiring information from the wireless tag to be communicated by wireless communication via the antenna;
Communication result transmission means for transmitting a communication result signal indicating whether or not information acquisition by the information acquisition means is possible to the operation terminal;
The position calculation means of the operation terminal is
A wireless tag position detection system that calculates the position of the wireless tag based on the communication result signals from at least two of the wireless tag communication apparatuses. The wireless tag position detection system according to claim 3,
The wireless tag communication device includes:
Position information storage means for storing and holding position information of the RFID tag communication device;
And a position information transmitting means for transmitting the position information stored and held in the position information storage means to the operation terminal in association with transmission of the communication result signal from the communication result transmitting means. Tag position detection system. The wireless tag position detection system according to claim 3,
The wireless tag communication device includes:
Identification information storage means for storing and holding identification information of the RFID tag communication device;
In connection with the transmission of the communication result signal from the communication result transmission means, the wireless communication system has an identification information transmission means for transmitting the identification information stored and held in the identification information storage means to the operation terminal. Tag position detection system. The wireless tag position detection system according to claim 4 or 5,
The communication instruction means of the operation terminal is
The communication instruction signal can be sequentially output in a predetermined order to at least two of the RFID tag communication devices,
The position calculation means of the operation terminal is
A position of the wireless tag is calculated based on the communication result signal respectively transmitted from the at least two wireless tag communication devices corresponding to the sequentially output communication instruction signals. Position detection system. The wireless tag position detection system according to claim 6,
The communication instruction means of the operation terminal is
Among the at least two RFID tag communication devices, the RFID tag communication device that is relatively close to the operation terminal is in an earlier order than the RFID tag communication device that is relatively far from the operation terminal, and the communication instruction A wireless tag position detection system that sequentially outputs signals. The wireless tag position detection system according to claim 7,
The communication instruction means of the operation terminal is
Of the at least two RFID tag communication devices, the RFID tag communication device closest to the operation terminal outputs the communication instruction signal first in preference to other RFID tag communication devices. Position detection system. The position detection system for a wireless tag according to claim 8,
The communication instruction means of the operation terminal is
When the RFID tag communication device closest to the operation terminal succeeds in acquiring information from the RFID tag by the information acquisition means, the communication instruction signal is then sent to the RFID tag communication device closest to the operation terminal. A position detection system for a wireless tag, wherein the position detection system outputs the position. The wireless tag position detection system according to any one of claims 6 to 9,
The wireless tag communication device includes:
In relation to the transmission of the communication result signal from the communication result transmitting means, the position information or the identification information of the RFID tag communication device which is in the next order along the predetermined order is transmitted to the operation terminal. A wireless tag position detection system comprising apparatus information transmission means. The wireless tag position detection system according to any one of claims 4 to 10,
The communication instruction means of the operation terminal is
The communication instruction signal is configured to be simultaneously output to at least two of the RFID tag communication devices,
The position calculation means of the operation terminal is
Position detection of the wireless tag, wherein the position of the wireless tag is calculated based on the communication result signal respectively transmitted from the at least two wireless tag communication devices in response to the communication instruction signal that is simultaneously output system. The wireless tag position detection system according to claim 11,
The communication instruction means of the operation terminal is
Of the at least two RFID tag communication devices, the RFID tag communication device closest to the operation terminal outputs the communication instruction signal first in preference to other RFID tag communication devices. Position detection system. The position detection system for a wireless tag according to claim 12,
The communication instruction means of the operation terminal is
When the RFID tag communication device closest to the operation terminal fails to acquire information from the RFID tag by the information acquisition means, the communication instruction signal is output simultaneously to the at least two RFID tag communication devices. A wireless tag position detection system. A plurality of radios that are arranged so that they can be connected to each other in a network, are arranged so that a communication area from an antenna partially overlaps with another RFID tag communication apparatus, and can transmit / receive information to / from radio tags located in the communication area An operation terminal capable of operating the tag communication device,
Communication instruction means for outputting a communication instruction signal to the wireless tag communication device so as to acquire information from the wireless tag to be communicated via wireless communication;
An operation terminal comprising: position calculation means for combining the communication area information of each wireless tag communication device that has acquired information from the wireless tag and calculating the position of the wireless tag. The operation terminal according to claim 14,
The communication instruction means includes
For the RFID tag communication device closest to the operation terminal among the at least two RFID tag communication devices, the communication instruction signal is output first with priority over other RFID tag communication devices,
When the RFID tag communication device closest to the operation terminal succeeds in acquiring information from the RFID tag by the information acquisition means, the communication instruction signal is then sent to the RFID tag communication device closest to the operation terminal. An operation terminal characterized by outputting. The operation terminal according to claim 15,
The communication instruction means includes
When the RFID tag communication device closest to the operation terminal fails to acquire information from the RFID tag by the information acquisition means, the communication instruction signal is output simultaneously to the at least two RFID tag communication devices. An operation terminal characterized by that. It is configured to be able to send and receive information to and from a radio tag located within a communication area from an antenna, and is arranged so that the communication area partially overlaps with another radio tag communication apparatus, and is connected to the other radio tag communication apparatus with a network A wireless tag communication device arranged in a possible manner,
Information acquisition means for acquiring information from the wireless tag to be communicated by wireless communication via the antenna based on the communication instruction signal from the operation terminal;
A wireless tag communication apparatus comprising: a communication result transmission unit configured to transmit a communication result signal indicating whether or not information acquisition by the information acquisition unit is possible to the operation terminal. The wireless tag communication device according to claim 17,
Position information storage means for storing and holding position information of the RFID tag communication device;
And a position information transmitting means for transmitting the position information stored and held in the position information storage means to the operation terminal in association with transmission of the communication result signal from the communication result transmitting means. Tag communication device. The wireless tag communication device according to claim 17,
Identification information storage means for storing and holding identification information of the RFID tag communication device;
In connection with the transmission of the communication result signal from the communication result transmission means, the wireless communication system has an identification information transmission means for transmitting the identification information stored and held in the identification information storage means to the operation terminal. Tag communication device. The wireless tag communication device according to claim 18 or 19,
In relation to the transmission of the communication result signal from the communication result transmitting means, the position information or the identification information of the RFID tag communication device that is in the next order along a predetermined order is sent to the operation terminal. A wireless tag communication device comprising: next device information transmitting means for transmitting.

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