Abstract:
An apparatus for managing information about an integrated circuit tag includes an acquiring unit and a storing unit. The acquiring unit acquires communication range information that is information about a range in which the integrated circuit tag communicates with an antenna of a reader/writer. The integrated circuit tag includes a transmitting device that transmits position identification information for identifying a position of the integrated circuit tag. The storing unit stores the communication range information in association with antenna identification information and integrated-circuit-tag identification information.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a technology for judging whether a range in which an IC tag communicates with a reader/writer is appropriate. 
     2. Description of the Related Art 
     In the conventional technology, at the time of installing an enterprise system using noncontact radio-frequency-identification (RFID) tags (hereinafter, “IC tags”), IC tags are located at positions within a range of receiving electric waves output by an antenna of a reader/writer (hereinafter, “electric-wave output range”). 
     Accordingly, a worker installing the IC tags estimates the electric-wave output range based on past experience and intuition, and locates each IC tag within the range estimated. Japanese Patent Application Laid Open No. H6-350516 discloses a technology for accurately measuring positions at which IC tags are set. 
     However, in the conventional technology, an electric-wave output range cannot be accurately identified, because it is estimated based on a worker&#39;s experience and intuition. 
     Specifically, the electric-wave output range is largely and irregularly affected by an environment surrounding the antenna and the IC tags. The worker cannot take this into consideration. 
     Moreover, the process of setting IC tags within the electric-wave output range based on the worker&#39;s experience and intuition is performed by a trial-and-error method. This imposes a significant load on the worker. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to at least solve the problems in the conventional technology. 
     According to an aspect of the present invention, an apparatus for managing information about an integrated circuit tag includes an acquiring unit that acquires communication range information, that is information about a range in which the integrated circuit tag communicates with an antenna of a reader/writer, where the integrated circuit tag includes a transmitting device that transmits position identification information for identifying a position of the integrated circuit tag; and a storing unit that stores the communication range information in association with antenna identification information for identifying the antenna, and integrated-circuit-tag identification information for identifying the integrated circuit tag. 
     According to another aspect of the present invention, an integrated circuit tag that stores information received from a reader/writer includes a transmitting unit that transmits position identification information for identifying a position of the integrated circuit tag; an acquiring unit that acquires communication range information that is information about a range in which the integrated circuit tag communicates with an antenna of the reader/writer, where the communication range information is identified by the position identification information; and a storing unit that stores the communication range information. 
     According to still another aspect of the present invention, a method of managing information about an integrated circuit tag includes acquiring communication range information that is information about a range in which the integrated circuit tag communicates with an antenna of a reader/writer, where the integrated circuit tag includes a transmitting device that transmits position identification information for identifying a position of the integrated circuit tag; and storing the communication range information in association with antenna identification information for identifying the antenna, and integrated-circuit-tag identification information for identifying the integrated circuit tag. 
     The above and other objects, features, advantages and technical and industrial significance of this invention will be better understood by reading the following detailed description of presently preferred embodiments of the invention, when considered in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of a tag-information management system according to an embodiment of the present invention; 
         FIG. 2  is a functional block diagram of a measurement PC shown in  FIG. 1 ; 
         FIG. 3  is an example of antenna-specific-tag information; 
         FIG. 4  is a diagram to explain a process performed by an electric-wave output-range determination unit shown in  FIG. 2 ; 
         FIG. 5  is a flowchart of a process procedure performed by a tag-information management unit shown in  FIG. 2 ; and 
         FIG. 6  is a flowchart of a process procedure performed by the electric-wave output-range determination unit. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Exemplary embodiments of the present invention will be described below with reference to the accompanying drawings. The present invention is not limited to these embodiments. 
     A tag-information management device according to an embodiment of the present invention employs an IC tag including an ultrasonic transmitter (hereinafter, “transmitter-tag”). The tag-information management device acquires information regarding a range in which the IC tag and an antenna of a reader/writer communicate (hereinafter, “communication range information”), stores the acquired communication range information in a storage unit, and writes the communication range information into the transmitter-tag. 
     Accordingly, at the time of installing IC tags, a worker can easily acquire the communication range information from the transmitter-tag with a handy terminal for radio-frequency-identification (RFID). Thus, the worker can accurately identify an electric-wave output range, thereby reducing a load on the worker when installing IC tags. 
       FIG. 1  is a block diagram of a tag-information management system according to the embodiment. The tag-information management system includes a transmitter-tag  10 , an RFID antenna  20 , an RFID reader/writer  30 , a hub  40 , a controller  50 , receivers  50   a  to  50   c , and a measurement personal computer (PC)  100 . The measurement PC  100  corresponds to the tag-information management device. 
     The RFID reader/writer  30  is connected to the RFID antenna  20  and the hub  40 ; the measurement PC  100  is connected to the hub  40  and the controller  50 ; and the controller  50  is connected to the receivers  50   a  to  50   c.    
     The transmitter-tag  10  is an IC tag that stores communication range information transmitted by the RFID antenna  20 . A transmitter attached to the transmitter-tag  10  transmits information (specifically, ultrasonic waves) for identifying a position of the transmitter-tag  10 . 
     The RFID antenna  20  outputs electric waves to the transmitter-tag  10 , and writes/reads information into/from the transmitter-tag  10 . The RFID reader/writer  30  uses the RFID antenna  20  to write/read information in/from the transmitter-tag  10 , in response to a read/write request from the measurement PC  100 . 
     The hub  40  connects the RFID reader/writer  30  and the measurement PC  100  to enable communication between them. The controller  50  measures a three-dimensional position coordinate of the transmitter-tag  10  (hereinafter, “position coordinate”) with the receivers  50   a  to  50   c , and sends the position coordinate measured to the measurement PC  100 . The position coordinate can be relative to an RFID tag, or an absolute position coordinate with respect to a specific location. 
     For example, the controller  50  causes the receivers  50   a  to  50   c  to receive ultrasonic waves transmitted by the transmitter-tag  10 , and measures the position coordinate by trigonometry. Before the controller  50  measures the position coordinate, a worker of the tag-information management system sets the transmitter-tag  10  at a critical point corresponding to the electric-wave output range of the RFID antenna  20 . 
     The measurement PC  100  uses the controller  50  to acquire communication range information, i.e. a position coordinate of the transmitter-tag  10 . Specifically, the measurement PC  100  acquires a position coordinate, stores the position coordinate acquired, and writes the position coordinate in the transmitter-tag  10  via the RFID reader/writer  30 . The measurement PC  100  acquires position coordinates of the transmitter-tag  10  at a plurality of locations corresponding to the critical points. 
       FIG. 2  is a functional block diagram of the measurement PC  100 . The measurement PC  100  includes an interface unit  110 , a tag-information management unit  120 , a storage unit  130 , an access unit  140 , an electric-wave output-range determination unit  150 , an input unit  160 , and a display unit  170 . 
     The interface unit  110  uses a predetermined communication protocol to communicate with the RFID reader/writer  30  and the controller  50 . The tag-information management unit  120  acquires a position coordinate from the controller  50 , acquires a tag identification (ID) for identifying the transmitter-tag  10 , and an antenna ID for identifying the RFID antenna  20  from the RFID reader/writer  30 , and stores the acquired information as the antenna-specific-tag information  130   a  in the storage unit  130 . 
       FIG. 3  is an example of a data structure of the antenna-specific-tag information  130   a . The antenna-specific-tag information  130   a  includes a tag ID, an antenna ID, and a position coordinate. For example, a tag ID “1001” has an antenna ID “2001” and a position coordinate “x=2.54, y=3.65, z=2.36”. A plurality of position coordinates is stored for each combination of a tag ID and an antenna ID. 
     Accordingly, the tag-information management unit  120  acquires from the controller  50 , position coordinates of the transmitter-tag  10  at a plurality of positions corresponding to the critical points, and stores the acquired position coordinates in the antenna-specific-tag information  130   a . To acquire a plurality of position coordinates, a worker moves the transmitter-tag  10  to different locations. 
     The access unit  140  sends the antenna-specific-tag information  130   a  to the RFID reader/writer  30 , and causes the RFID reader/writer  30  to write the antenna-specific-tag information  130   a  in the transmitter-tag  10 . The access unit  140  can cause the RFID reader/writer  30  to write all information included in the antenna-specific-tag information  130   a  into the transmitter-tag  10 , or only relevant information (e.g., information corresponding to the tag ID of the transmitter-tag  10 ). 
     The electric-wave output-range determination unit  150  determines whether an electric-wave output range of the RFID antenna  20  is appropriate. The electric-wave output-range determination unit  150  reads the antenna-specific-tag information  130   a , and creates an approximation surface based on position coordinates having the same tag ID and the same antenna ID. The electric-wave output-range determination unit  150  stores a tag ID in association with an antenna ID, on which the approximation surface is based. 
     The electric-wave output-range determination unit  150  acquires once again from the controller  50 , a tag ID of the transmitter-tag  10 , an antenna ID of the RFID antenna  20 , and apposition coordinate of the transmitter-tag  10 . The electric-wave output-range determination unit  150  determines whether the acquired position coordinate is within a tolerance range with respect to the approximation surface, and outputs a result of this determination to the display unit  170 . The display unit  170  displays information acquired from the electric-wave output-range determination unit  150  on a display device (not shown). 
       FIG. 4  is a diagram to explain a process performed by the electric-wave output-range determination unit  150 . When maintenance is performed on the tag-information management system, a worker uses a handy terminal to acquire a position coordinate from the transmitter-tag  10 , and locates the transmitter-tag  10  at a position corresponding to the acquired position coordinate. The worker inputs into the measurement PC  100 , that the transmitter-tag  10  has been located at the position, using an input device such as a keyboard (not shown). 
     The electric-wave output-range determination unit  150  acquires information through the input unit  160  that the transmitter-tag  10  has been located at the position, and determines whether the electric-wave output range is appropriate. The input unit  160  passes information input from the keyboard to the electric-wave output-range determination unit  150 . The worker locates the transmitter-tag  10  at a plurality of positions corresponding to position coordinates. At each position, the electric-wave output-range determination unit  150  determines whether the electric-wave output range is appropriate. By repeating this process, the worker can easily determine whether the electric-wave output range is appropriate. 
     A worker may also acquire a position coordinate through the measurement PC  100 . In this case, the worker inputs a position coordinate request in the measurement PC  100  through an input device. Upon receiving the position coordinate request through the input unit  160 , the electric-wave output-range determination unit  150  in the measurement PC  100  acquires the antenna-specific-tag information  130   a  from the storage unit  130 , and outputs the acquired antenna-specific-tag information  130   a  on the display unit  170 . 
       FIG. 5  is a flowchart of a process procedure performed by the tag-information management unit  120 . The tag-information management unit  120  acquires a position coordinate of the transmitter-tag  10  from the controller  50  (step S 101 ). 
     The tag-information management unit  120  acquires a tag ID of the transmitter-tag  10  (step S 102 ), and acquires an antenna ID of the RFID antenna  20  (step S 103 ), from the RFID reader/writer  30 . 
     The position coordinate, the tag ID, and the antenna ID are stored in association with each other as the antenna-specific-tag information  130   a  in the storage unit  130  (step S 104 ). Accordingly, a worker can easily identify an electric-wave output range using the antenna-specific-tag information  130   a.    
     Moreover, because the access unit  140  writes the antenna-specific-tag information  130   a  into the transmitter-tag  10 , a worker can acquire a precise electric-wave output range from the transmitter-tag  10  with the handy terminal. Thus, a load on the worker when installing IC tags reduces. 
       FIG. 6  is a flowchart of a process procedure performed by the electric-wave output-range determination unit  150 . The electric-wave output-range determination unit  150  creates an approximation surface based on position coordinates in the antenna-specific-tag information  130   a  (step S 201 ). The electric-wave output-range determination unit  150  acquires a position coordinate from the controller  50 , and acquires a tag ID and an antenna ID from the transmitter-tag  10  (step S 202 ). 
     When the tag ID and the antenna ID on which the approximation surface is based match the tag ID and the antenna ID acquired from the transmitter-tag  10 , the electric-wave output-range determination unit  150  compares the approximation surface and the position coordinate acquired from the controller  50 , and determines whether the electric-wave output range is appropriate, i.e. whether the position coordinate is within a tolerance range with respect to the approximation surface (step S 203 ). 
     If the electric-wave output range is appropriate (Yes at step S 204 ), the electric-wave output-range determination unit  150  displays on the display device through the display unit  170  that the electric-wave output range is appropriate (step S 205 ). 
     If the electric-wave output range is not appropriate (No at step S 204 ), the electric-wave output-range determination unit  150  displays on the display device through the display unit  170  that the electric-wave output range is not appropriate (step S 206 ). 
     Thus, a load on the worker when performing maintenance on the tag-information management system reduces. 
     The tag-information management unit  120  in the measurement PC  100  acquires a tag ID, an antenna ID, and a position coordinate, and stores this information as antenna-specific-tag information  130   a  in the storage unit  130 . The access unit  140  stores the antenna-specific-tag information  130   a  in the transmitter-tag  10 . Thus, a worker installing IC tags can easily identify a precise electric-wave output area. 
     In addition to the tag ID, the antenna ID, and the position coordinate, information regarding an environment in which the position coordinate is measured can be stored in the storage unit  130  as the antenna-specific-tag information  130   a.    
     Thus, the electric-wave output range can be accurately identified regardless of irregular changes in the environment that affect the electric-wave output area. 
     According to the present invention, a worker who is installing tags can accurately identify a range to which electric waves are output from an antenna. 
     Furthermore, a worker who is installing tags can accurately identify a range in which electric waves are output from an antenna, so that IC tags are installed at appropriate positions. 
     Moreover, a worker can easily determine whether an electric-wave output range of an antenna is appropriate, so that a load on the worker when performing maintenance on the antenna reduces. 
     Although the invention has been described with respect to a specific embodiment for a complete and clear disclosure, the appended claims are not to be thus limited but are to be construed as embodying all modifications and alternative constructions that may occur to one skilled in the art that fairly fall within the basic teaching herein set forth.