Tag communication device, tag communication system, and storage medium

Abstract

This invention discloses a tag communication device, a tag communication system, and a storage medium. The tag communication device includes a communication unit, a selection unit, a request unit, a rewriting unit, and a control unit. The selection unit sends a first command from the communication unit to notify a wireless tag of its selection, which includes an identification code containing a mask pattern that is part of a common portion of the identification code. The request unit sends a second command from the communication unit to request a response from the selected wireless tag. The rewriting unit, based on data received from the wireless tag in response to the second command via the communication unit, sends a third command requesting rewriting from the communication unit to the wireless tag that transmitted the data. The control unit, before transmitting the third command to a predetermined number of wireless tags, repeats the transmission of the second command if the third command has already been transmitted, or if no data was received from the wireless tag in response to the second command.

Description

[0001] This application claims priority to Japanese application No. JP2021-142620, filed on September 1, 2021, and incorporates the contents of the aforementioned application in their entirety. Technical Field

[0002] Embodiments of the present invention relate to a tag communication device, a tag communication system, and a storage medium. Background Technology

[0003] There are known image forming apparatuses that, while forming an image on a printing medium containing multiple labels on which wireless tags are respectively attached, individually rewrite the identification code of each wireless tag.

[0004] However, in tag communication devices applied to such image forming apparatuses, since multiple wireless tags exist close together, it is necessary to take mechanical measures, such as configuring radio wave shielding components, so that these multiple wireless tags can communicate one by one in sequence.

[0005] In this situation, there is an expectation for a technology that can rewrite the identification codes of multiple wireless tags with a simple configuration. Summary of the Invention

[0006] In view of the above problems, the technical problem to be solved by the present invention is to provide a tag communication device, a tag communication system and a storage medium, which can rewrite the identification code of multiple wireless tags with a simple configuration.

[0007] To address the aforementioned problems, an embodiment of the tag communication device of the present invention includes a communication unit for wirelessly communicating with a plurality of wireless tags that each store a first identification code containing at least a known common portion in a tag memory. The wireless tags include: a mask pattern storage unit, which stores a mask pattern contained in the first command in the tag memory when a first command is received via a selection unit; a response completion determination unit, which determines whether to send response data when a second command is received via a request unit; and a response data sending unit, which ignores the second command if the response completion determination unit determines that response data has been sent, and ignores the second command if the response completion determination unit determines that no response data has been sent. If the first identification code is consistent with the mask pattern, the value of the third counter is set, and the response data is sent if the value of the third counter is a preset value; the response completion information setting unit sets information indicating that the response data has been sent if the response data sending unit has sent the response data; the identification code sending unit sends notification data containing the first identification code when it receives a response receiving command sent by the response receiving command sending unit; and the second identification code storage unit rewrites the first identification code into a second identification code contained in the third command when it receives a third command sent by the rewriting unit. The tag communication device includes: a first counter setting unit for setting a first counter value equivalent to the number of the plurality of wireless tags; a selection unit for sending a first command from a communication unit, the first command being used to designate at least a portion of a common part as a mask pattern and to notify the selection of a wireless tag having a first identification code including the mask pattern; a second counter setting unit for setting a limited number of times a second command for requesting response data from the selected wireless tag is repeatedly sent; a request unit for sending the second command from the communication unit; a response receiving command sending unit for sending a response receiving command requesting the first identification code after sending the second command, provided that the response data is received within a predetermined time; and a rewriting unit for rewriting the first identification code after receiving the first identification code. The wireless tag with the first identification code sends a third command from the communication unit requesting the rewriting of the first identification code, which includes a second identification code different from the mask pattern; the first counter update unit updates the value of the first counter when the rewriting unit's processing is executed; the second counter update unit updates the second counter when no response data is received, and when it is determined based on the updated value of the first counter that the rewriting of all wireless tags has not been completed; and the control unit determines whether the predetermined number of times has been reached based on the value of the second counter, and if the predetermined number of times has been reached, executes the processing of the selection unit that sends the first command again, and if the predetermined number of times has not been reached, executes the processing of the request unit that sends the second command again.

[0008] According to the tag communication device described above, a tag communication device is provided that can rewrite the first identification code of multiple wireless tags with a simple configuration.

[0009] In the aforementioned tag communication device, the rewriting unit requests a rewriting of the tag to a different second identification code each time a third command is sent.

[0010] According to the tag communication device described above, the first identification code of multiple wireless tags can be rewritten into different second identification codes.

[0011] Another aspect of the present invention provides a tag communication system comprising a plurality of wireless tags and a tag communication device. Each wireless tag stores a first identification code in a tag memory, each code containing at least a known common portion. The tag communication device has a communication unit for wirelessly communicating with the wireless tags. The tag communication device includes: a first counter setting unit for setting a first counter value corresponding to the number of the plurality of wireless tags; a selection unit for sending a first command from the communication unit, the first command being used to designate at least a portion of the common portion as a mask pattern and to notify the selection of a wireless tag having a first identification code containing the mask pattern; and a second counter setting unit for repeatedly sending commands to the selected wireless tag. The system includes: a limited number of times a second command requesting response data is sent to the wireless tag; a request unit for sending the second command from the communication unit; a response receiving command sending unit that, after sending the second command, sends a response receiving command requesting the first identification code if the response data is received within a specified time; a rewriting unit that, upon receiving the first identification code, sends a third command from the communication unit requesting the rewriting of the first identification code, containing a second identification code different from the mask pattern, for the wireless tag that sent the first identification code; a first counter update unit that updates the value of the first counter when the rewriting unit's processing is executed; and a second counter update unit that, when no response data is received... In the case of the response data, and if it is determined based on the updated value of the first counter that the rewriting of all wireless tags has not been completed, the second counter is updated; and the control unit determines based on the value of the second counter whether the predetermined number of times has been reached. If the predetermined number of times has been reached, the processing of the selection unit that sends the first command is executed again; if the predetermined number of times has not been reached, the processing of the request unit that sends the second command is executed again. The wireless tag includes: a mask pattern storage unit that stores the mask pattern contained in the first command in the tag memory when receiving the first command sent through the selection unit; and a response completion determination unit that, when receiving the second command sent through the request unit... The system determines whether to send the response data; the response data sending unit, if the response completion determination unit determines that response data has been sent, ignores the second command; if it determines that no response data has been sent, and if it has the first identification code that matches the mask pattern, it sets the value of the third counter; if the value of the third counter is a preset value, it sends the response data; the response completion information setting unit, if the response data sending unit has sent the response data, sets information indicating that the response data has been sent; the identification code sending unit, when receiving a response receiving command sent by the response receiving command sending unit, sends notification data containing the first identification code.And a second identification code storage unit, which, upon receiving the third command sent through the rewriting unit, rewrites the first identification code into a second identification code included in the third command.

[0012] Based on the aforementioned tag communication system, a wireless communication system is provided that can rewrite the first identification code of multiple wireless tags with a simple configuration.

[0013] In the aforementioned tag communication system, the tag communication device stops transmitting radio waves when it determines, based on the value of the first counter updated by the first counter update unit, that the rewriting of all wireless tags has been completed.

[0014] According to the aforementioned tag communication system, it is possible to properly stop the transmission of radio waves after completing the rewriting of all wireless tags.

[0015] In the aforementioned tag communication system, when the wireless tag sets the value of the third counter, it randomly determines a value within a pre-set range.

[0016] According to the tag communication system described above, the value of the third counter can be set for various numbers of wireless tags by random determination.

[0017] In the aforementioned tag communication system, the rewriting unit requests a rewriting of the tag into a different second identification code each time it sends a third command.

[0018] According to the tag communication system described above, the first identification code of multiple wireless tags can be rewritten into different second identification codes.

[0019] In the aforementioned tag communication system, the tag communication device is disposed on an image forming apparatus, the image forming apparatus forms an image on a printing medium comprising multiple labels, and the wireless tags are respectively installed on the multiple labels of the printing medium.

[0020] According to the aforementioned tag communication system, the first identification code can be rewritten in an image forming apparatus that uses a label-attached sheet as a printing medium with a simple configuration.

[0021] Another aspect of the present invention provides a storage medium that stores an information processing program that enables a processor of a tag communication device comprising a communication unit for wirelessly communicating with a plurality of wireless tags, each storing in a tag memory a first identification code containing at least a known common portion, to function as the following units: the wireless tag includes: a mask pattern storage unit that stores a mask pattern contained in a first command in the tag memory when a first command is received via a selection unit; a response completion determination unit that determines whether to send response data when a second command is received via a request unit; and a response data transmission unit that, when the response completion determination unit determines that response data has been sent. Ignoring the second command, if it is determined that no response data has been sent, and if the first identification code is consistent with the mask pattern, the value of the third counter is set, and if the value of the third counter is a preset value, the response data is sent; the response completion information setting unit sets information indicating that the response data has been sent when the response data sending unit has sent the response data; the identification code sending unit sends notification data containing the first identification code when it receives a response reception command sent by the response reception command sending unit; and the second identification code storage unit stores the first identification code when it receives a third command sent by the rewriting unit. The identification code is rewritten as a second identification code included in the third command. Each part includes: a first counter setting unit, which sets a first counter value equivalent to the number of the plurality of wireless tags; a selection unit, which sends a first command from the communication unit, the first command being used to designate at least a portion of the common part as a mask pattern and to notify the selection of a wireless tag having a first identification code including the mask pattern; a second counter setting unit, which sets a limited number of times a second command for requesting response data from the selected wireless tag is repeatedly sent; a request unit, used to send the second command from the communication unit; and a response receiving command sending unit, which, after sending the second command, responds to a response within a specified time... Upon receiving the response data, a response reception command requesting the first identification code is sent; the rewriting unit, upon receiving the first identification code, sends a third command from the communication unit to the wireless tag that sent the first identification code, requesting the rewriting of the first identification code and including a second identification code different from the mask pattern; the first counter update unit updates the value of the first counter when the processing of the rewriting unit is executed; the second counter update unit updates the second counter when no response data is received, and when it is determined based on the updated value of the first counter that the rewriting of all wireless tags has not been completed.The control unit determines, based on the value of the second counter, whether the predetermined number of times has been reached. If it has, the selection unit's processing of sending the first command is executed again. If the predetermined number of times has not been reached, the request unit's processing of sending the second command is executed again.

[0022] Based on the aforementioned storage medium, the processor can be provided with the ability to rewrite the first identification code of multiple wireless tags with a simple configuration. Attached Figure Description

[0023] Figure 1 This is a block diagram illustrating the essential circuit configuration of a multifunction printer according to one embodiment;

[0024] Figure 2 This is an example of a label sheet with a label attached;

[0025] Figure 3 It means Figure 1 A block diagram of the essential circuitry of the tag communication unit in the diagram;

[0026] Figure 4 Through Figure 3 The flowchart of the rewriting process performed by the processor in the process;

[0027] Figure 5 This is a diagram illustrating an example of the communication sequence between the tag communication unit and the wireless tag, as well as the state changes of the wireless tag;

[0028] Figure 6 This is a diagram illustrating an example of the communication sequence between the tag communication unit and the wireless tag, as well as the state changes of the wireless tag;

[0029] Figure 7 This is a diagram illustrating an example of the communication sequence between the tag communication unit and the wireless tag, as well as the state changes of the wireless tag;

[0030] Figure 8 This is a diagram illustrating an example of the communication sequence between the tag communication unit and the wireless tag, as well as the state changes of the wireless tag;

[0031] Figure 9 This is a diagram illustrating an example of the communication sequence between the tag communication unit and the wireless tag, as well as the state changes of the wireless tag;

[0032] Figure 10 This is a diagram illustrating an example of the communication sequence between the tag communication unit and the wireless tag, as well as the state changes of the wireless tag; and

[0033] Figure 11 This is a diagram illustrating an example of the communication sequence between the tag communication unit and the wireless tag, as well as the state changes of the wireless tag.

[0034] Explanation of reference numerals in the attached figures

[0035] 1. Multifunction printer; 2. Communication network; 10. Processor

[0036] 11 Main memory 12 Auxiliary storage unit 13 Operation / display unit

[0037] 14 Scanning unit 15 Image forming unit 16 Fax unit

[0038] 17 Tag communication unit; 18 External communication unit; 19 Transmission line

[0039] 171 Modulation section; 172 Transmitter amplifier; 173 Circulator

[0040] 174 Antenna; 175 Receiver Amplifier; 176 Demodulation Unit

[0041] 177 Control Unit 178 Interface 1771 Processor

[0042] 1772 Storage Department TA, TAA~TAE Wireless Tags Detailed Implementation

[0043] Hereinafter, an example of an embodiment will be described using the accompanying drawings. Furthermore, in this embodiment, a tag communication device installed in a multifunction printer (image forming apparatus) will be used as an example for description.

[0044] Figure 1 This is a block diagram illustrating the main circuit configuration of the multifunction machine 1 involved in this embodiment.

[0045] A multifunction printer 1 is a device that combines the functions of a copier, scanner, printer, and fax machine. However, it may not be necessary to include all of these functions, or it may include other functions such as a document server. Furthermore, a multifunction printer 1 is also called an MFP (multi-function peripheral).

[0046] The multifunction printer 1 includes a processor 10, a main memory 11, an auxiliary storage unit 12, an operation / display unit 13, a scanning unit 14, an image forming unit 15, a fax unit 16, a tag communication unit 17 (tag communication device), an external communication unit 18, and a transmission line 19. The processor 10, main memory 11, auxiliary storage unit 12, operation / display unit 13, scanning unit 14, image forming unit 15, fax unit 16, tag communication unit 17, and external communication unit 18 are connected via the transmission line 19.

[0047] A computer for information processing is constructed by connecting the processor 10, main memory 11 and auxiliary storage unit 12 via transmission line 19.

[0048] The processor 10 is equivalent to the central part of the computer described above. The processor 10 performs information processing according to the information processing programs of the operating system, middleware, and application programs.

[0049] Main memory 11 corresponds to the main storage portion of the computer described above. Main memory 11 includes non-volatile memory areas and volatile memory areas. Main memory 11 stores information processing programs in the non-volatile memory areas. In addition, main memory 11 sometimes stores data required by the processor 10 for controlling various parts during processing, either in non-volatile or volatile memory areas. Main memory 11 uses the volatile memory areas as working areas where data can be appropriately rewritten by the processor 10.

[0050] The auxiliary storage unit 12 corresponds to the auxiliary storage portion of the computer described above. As the auxiliary storage unit 12, known storage devices such as EEPROM (electrically erasable programmable read-only memory), HDD (hard disk drive), and SSD (solid-state drive) can be used individually or in combination. The auxiliary storage unit 12 stores data used by the processor 10 in various processes, or data generated by the processes performed by the processor 10. The auxiliary storage unit 12 stores information processing programs. A portion of the storage area of ​​the auxiliary storage unit 12 is used to store the configuration file FIA, which will be described later.

[0051] The operation / display unit 13 inputs operations performed by the user using the multifunction printer 1 while displaying various information to prompt the user. The operation / display unit 13 may appropriately include various operating and display devices such as a touch panel, keyboard, key switches, LEDs, or LCD panel.

[0052] The scanning unit 14 reads the original document and generates image data showing the image of the original document.

[0053] The image forming unit 15 forms an image representing image data for a printing medium. The image forming unit 15 includes known image forming apparatuses such as an electronic photographic image forming unit. While various known media, such as cut-out paper, can be used as the printing medium, one of these includes label sheets with attached labels.

[0054] Figure 2 This is an example of a label sheet with a label attached.

[0055] Figure 2 The labeled sheet refers to a sheet of paper with tags attached, for example, an A4 sheet of paper (MOA) with labels RAA, RAB, RAC, RAD, and RAE respectively affixed to it. Furthermore, wireless tags are also called RFID (radio frequency identification) tags. In the following text, unless there is a specific need for further distinction, wireless tags TAA, TAB, TAC, TAD, and TAE will be referred to as wireless tag TA.

[0056] The wireless tag TA is a passive RFID tag. The wireless tag TA has a built-in antenna, tag memory, and tag control unit. The wireless tag generates power by communicating wirelessly with the tag communication unit 17. The tag memory stores the program required for wireless communication with the tag communication unit 17. The tag memory also stores necessary information based on the setting data received from the wireless communication device. The tag memory also stores a pre-set identification code. The tag control unit executes the program. The wireless tag TA and the tag communication unit 17 constitute a tag communication system.

[0057] also, Figure 2 The labeled stickers shown are just one example; the size of the backing paper, the size of the sticker, the number of stickers, the size of the sticker, the shape of the sticker, the position of the sticker on the backing paper, or the installation position of the wireless tag in the sticker can be arbitrary. Alternatively, several different types of labeled stickers can be used selectively.

[0058] However, below, regarding the Figure 2 The use of labeled stickers as printing media is described in detail.

[0059] Figure 1 The fax unit 16 performs various known processes for image communication conforming to fax standards via communication networks such as PSTN (public switched telephone network) (not shown).

[0060] When a label with a label attached is used as a printing medium, the tag communication unit 17 wirelessly communicates with a plurality of wireless tags TA installed on the printing medium. Furthermore, the tag communication unit 17 can communicate with the wireless tags TA at any time, before the printing medium is fed into the image forming unit 15, during image forming of the printing medium by the image forming unit 15, or after the printing medium is ejected from the image forming unit 15.

[0061] The external communication unit 18 performs communication processing for data communication with external devices of the multifunction printer 1 via the communication network 2. The external communication unit 18 can use existing communication equipment, such as LAN (local area network).

[0062] The transmission line 19 includes an address bus, a data bus, and control signal lines, which transmit and receive data and control signals between the connected parts.

[0063] Figure 3 This is a block diagram showing the main circuit configuration of the tag communication unit 17 (tag communication device).

[0064] The tag communication unit 17 includes a modulation unit 171, a transmitting amplifier 172, a circulator 173, an antenna 174, a receiving amplifier 175, a demodulation unit 176, a control unit 177, and an interface 178.

[0065] The modulation unit 171 obtains a transmission signal by modulating a carrier wave with data obtained from the control unit 177. Furthermore, when the modulation unit 171 does not receive data from the control unit 177, it can also output an unmodulated carrier wave directly as a transmission signal.

[0066] The transmitting amplifier 172 amplifies the transmitting signal output from the modulation unit 171, making it a signal state suitable for wireless transmission.

[0067] The circulator 173 outputs the transmit signal from the transmit amplifier 172 to the antenna 174. The circulator 173 outputs the receive signal obtained from the antenna 174 to the receive amplifier 175, as described later. Thus, the circulator 173 can share the antenna 174 for both transmission and reception.

[0068] Antenna 174 transmits radio waves corresponding to the transmitted signal obtained from circulator 173. Antenna 174 outputs the electrical signal corresponding to the radio waves propagating through space as a received signal to circulator 173.

[0069] The receiver amplifier 175 amplifies the weak received signal obtained at the antenna 174 based on the weak radio waves transmitted from the wireless tag TA to the antenna 174, making it a signal state suitable for processing in the demodulation unit 176.

[0070] When the received signal is a data-based modulated signal, the demodulation unit 176 demodulates the data.

[0071] Based on the above-mentioned modulation unit 171, transmitting amplifier 172, circulator 173, receiving amplifier 175 and demodulation unit 176, and possibly also including antenna 174, the function of the communication unit is realized.

[0072] In order to communicate with the radio tag TA according to a pre-defined communication standard, the control unit 177 outputs data to the modulation unit 171 and processes the data obtained in the demodulation unit 176. The control unit 177 receives various data, such as setting data, for communicating with the radio tag TA through the transmission line 19 via the interface 178. The control unit 177 also notifies the processor 10 of various data, such as data read from the radio tag TA, through the transmission line 19 via the interface 178.

[0073] The control unit 177 includes a processor 1771 and a storage unit 1772. The processor 1771 includes a CPU (central processing unit). The processor 1771 may also include a high-speed signal processing processor using an ASIC (application-specific integrated circuit) or similar technology. While controlling the operation of each part of the tag communication unit 17, the processor 1771 performs information processing and signal processing for generating, outputting, and receiving data to be transmitted, so as to transmit and receive data in a sequence conforming to communication standards. The storage unit 1772 stores the information processing program used by the processor 1771. Additionally, the storage unit 1772 is used as a work area to store data required by the processor 1771 for performing information processing or signal processing. The storage unit 1772 stores setting data received through the interface 178. The setting data is specified according to the operation performed by the operator on the operation / display unit 13. The setting data includes the number of tags (tag number information), a mask pattern, and multiple rewritten identification codes (second identification codes). The storage unit 1772 has the function of a storage unit (first storage unit) for storing setting data.

[0074] One of the information processing programs stored in storage unit 1772 is a rewrite program PRA, which is related to and described later in the rewrite process. The rewrite program PRA can be stored in storage unit 1772 when the multifunction printer 1 is transferred, or it can be written to storage unit 1772 after the transfer of the multifunction printer 1, based on the operation of the user or maintenance personnel of the multifunction printer 1. The latter, for example, assumes that the rewrite program PRA is provided as a version upgrade program. The transfer of the rewrite program PRA is assumed to be performed via communication through a network. However, the transfer of the rewrite program PRA can also be performed on a removable storage medium such as a disk, magneto-optical disk, optical disk, or semiconductor memory.

[0075] Interface 178 performs interface processing for data communication via transmission line 19.

[0076] Next, the operation of the multifunction printer 1 configured as described above will be explained. Furthermore, the processing described below is just one example; the order of some processing steps can be appropriately changed, some steps can be omitted, or other processing steps can be added. In this embodiment, the wireless communication between the tag communication unit 17 and the wireless tag TA is performed in accordance with ISO (international standards organization) / IEC (international electrotechnical commission) 18000-6 Type C.

[0077] The multifunction printer 1 operates to perform various functions such as a copier, scanner, printer, and fax machine. This operation may also be the same as that of other multifunction printers of the same type. A characteristic operation of the multifunction printer 1 in this embodiment is the operation of rewriting the identification code of the wireless tag TA. Therefore, the following description will focus on this operation. Furthermore, the identification code of the wireless tag TA is also called the EPC (electronic product code).

[0078] As a prerequisite, at least a common identification code (first identification code) is pre-set in the tag memory of each of the wireless tags TAA to TAE. In this embodiment, all wireless tags TAA to TAE are set to the same identification code (first identification code). This identification code is "3008 33B2 DDD9 0140 0000 0000". This identification code is the identification code set at the factory for the "Monza 5" product manufactured by Impinj. However, it is also possible to set different but common codes at the beginning of each wireless tag TAA to TAE. Wireless tags TAA to TAE store the identification code set above in their built-in tag memory.

[0079] As for the future Figure 2The number of labels (label information) shown is set to "5" in the printing-related settings for the printed media. The mask pattern for this setting can be any code that is a common part of the unwritten identification codes (first identification codes) of the wireless tags TAA to TAE, but here it is "3008 33B2" (equivalent to the first 8 digits). The mask pattern can also be all of the common parts of the identification codes. Furthermore, the rewritten identification code (second identification code) for this setting can also be any code, but here it is "3010 2EDA F110 F040 0000 0001" to "3010 2EDA F110 F040 0000 0005". The rewritten identification codes (second identification codes) are five different codes. However, the rewritten identification codes should be determined in a way that the mask patterns are inconsistent. Alternatively, the rewritten identification codes can be set so that all five or a portion thereof are the same. The setting data representing these settings, for example, is generated by the processor 10 based on the operation of the operator of the operation / display unit 13, and is included in the setting file FIA. The setting file FIA ​​stores the setting data. The setting data includes the number of tags (tag number information), the mask pattern, and multiple rewritten identification codes (second identification codes). The setting data can be transmitted via the communication network 2 from... Figure 1 The server device or computer device (not shown in the figure) is used to obtain the information and it is included in the configuration file FIA. Furthermore, the auxiliary storage unit 12 includes and stores the code specified by the operator as a mask pattern in the configuration file FIA, thus functioning as a second storage unit.

[0080] If the processor 10 generates a rewrite of the accompanying identification code based on the operation / display unit 13 or a request received via the communication network 2, and printing of the labeled label sheet is required, the image forming unit 15 operates as known, forming an image on the printing medium, and simultaneously instructs the label communication unit 17 to perform the rewrite. Then, the processor 10 reads the aforementioned setting data from the setting file FIA ​​and sends it to the label communication unit 17. Alternatively, when printing begins based on a request received via the communication network 2, the processor 10 may directly send the setting data obtained via the communication network 2 to the label communication unit 17.

[0081] When the tag communication unit 17 receives data sent from the processor 10 via the interface 178 to indicate the rewriting process, the processor 1771 begins the rewriting process according to the rewriting program PRA.

[0082] Figure 4 This is a flowchart of the rewrite process based on processor 1771.

[0083] As described above, in ACT1, processor 1771 obtains setting data sent from processor 10 via interface 178. Furthermore, processor 1771 stores the obtained setting data in storage unit 1772.

[0084] As ACT2, processor 1771 sets the number of wireless tags represented by the setting data (first counter value) in variable M (first counter) (first counter setting unit). In summary, in this embodiment, processor 1771 sets the number of tags (tag number information) in variable M to "5" (first counter value). Variable M is a variable used to manage the number of wireless tags (TAs) whose identification codes should be rewritten.

[0085] As ACT3, processor 1771 begins radio wave transmission. For example, processor 1771 outputs a carrier wave, which is not modulated according to data, as a transmission signal to modulation unit 171. After the transmission signal is amplified by transmission amplifier 172, it is supplied to antenna 174 via circulator 173, thereby starting the transmission of radio waves from antenna 174.

[0086] In this way, when the radio wave emitted from antenna 174 reaches the wireless tag TA, the wireless tag TA starts to operate based on the power received from the radio wave. Then, the tag control unit of the tag TA generates, for example, a 16-bit random number RN and stores it in the tag memory.

[0087] Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9 , Figure 10 and Figure 11 This is a diagram illustrating an example of the communication sequence between tag communication unit 17 and wireless tags TAA~TAE, and the state changes of wireless tags TAA~TAE.

[0088] As Figure 5 In event EAA, based on the radio wave transmission status starting from tag communication unit 17, the tag control units of wireless tags TAA~TAE respectively generate random numbers RN for “AA”, “AB”, “AC”, “AD”, and “AE”. Furthermore, “AA”, “AB”, “AC”, “AD”, and “AE” each represent any 16-bit value. Multiple values ​​among “AA”, “AB”, “AC”, “AD”, and “AE” may also be the same.

[0089] As ACT4, processor 1771 sends a Select command. During the transmission of the Select command and various other commands described later, processor 1771 generates and outputs data corresponding to each command. Thus, the transmission signal modulated according to the Select command is obtained by modulation unit 171, amplified in transmission amplifier 172, and then wirelessly transmitted from antenna 174. Processor 1771 includes the mask pattern represented in the setting data obtained in ACT1 in the Select command. The transmission of this Select command is... Figure 5 Event EAB. The Select command is received by each of the wireless tags TAA to TAE. The tag control unit that receives the Select command stores a mask pattern in the tag memory (mask pattern storage unit). The Select command is a command used to specify a mask pattern and notify the user of the selection of a wireless tag TA with an identification code containing that mask pattern; it is equivalent to the first command. Furthermore, the processor 1771 performs information processing based on the rewrite program PRA, and the processor 1771 functions as the selection unit. In addition, the mask pattern represented by the setting data obtained in ACT1 is a mask pattern in which the code stored in the auxiliary storage unit 12, which is the second storage unit, is stored in the storage unit 1772 (the first storage unit). Therefore, as the selection unit of the processor 1771, the code stored in the auxiliary storage unit 12 and the storage unit 1772 is used as the mask pattern.

[0090] As ACT5, after the processor 1771 executes the selection unit's processing, it initializes the variable N (second counter). Variable N is a variable (second counter value) used to manage the number of repetitions of tag detection. For example, the processor 1771 sets a preset number (second counter value) as the variable N (second counter setting unit) as a limit number of tag detection repetitions. Variable N can be a number independent of the number of tags. However, it is more efficient to use a number that is the same as the number of tags. Therefore, for example, variable N is "5".

[0091] As ACT6, processor 1771 sends a Query command. The sending of this Query command is... Figure 5 The event EAC. The Query command is received by each of the radio tags TAA to TAE. This Query command, and the QueryRep command described later, are commands used to request a response from the radio tag selected by the Select command, equivalent to the second command. Furthermore, the processor 1771 performs information processing based on the rewritten program PRA, thereby functioning as the request unit.

[0092] When the tag control unit of the RFID tag TA receives the Query command, it determines whether response data has been sent previously (response completion determination unit). Specifically, it determines whether the response completion flag is "1" or "0". Since the response completion flag is initially "0", it determines whether the mask pattern stored in the tag memory is included in its own identification code. If the RFID tag TA has an identification code that matches the mask pattern stored in the tag memory, the tag control unit randomly determines the counter value CV (third counter) (third counter setting unit) to a value within a preset range (e.g., 5) (third counter value). The counter value CV is referenced when sending response data. By randomly determining the value, it is not necessary to predetermine the RFID tag TA that is responding. Therefore, it can be used with various numbers of RFID tags. The tag control unit sets the counter value CV in the tag memory. The third counter setting unit updates the set third counter value and performs a reset process. RFID tags TAA to TAE all have identification codes that match the mask pattern, so according to... Figure 5 The event EAC generates counter values ​​CV as "3", "0", "3", "2", and "4" respectively. Because each wireless tag (TA) generates counter values ​​CV independently, as in the example above, multiple counter values ​​CV may have the same value.

[0093] Furthermore, it is predetermined that response data will be transmitted when the counter value CV is "0". The tag control unit of the radio tag TA transmits response data to notify the random number RN when the determined counter value CV is "0". In addition, the transmission of response data from the radio tag TA and various other data described later may be performed, for example, using backscatter communication. The tag control unit determines whether a radio tag is authorized to respond by judging that the counter value CV is the preset value "0" (response tag determination unit).

[0094] exist Figure 5 In the example, because only the counter value CV of the wireless tag TAB is determined to be "0", therefore, as Figure 6 In the event EBA, the tag control unit of the wireless tag TAB sends response data (response data sending unit) containing data of "AB" indicating that it is its own random number RN. After sending the response data, the tag control unit of the wireless tag TAB sets the response completion flag indicating that the response data has been sent to "1" (response completion information setting unit) and stands by to receive the ACK command (response receive command).

[0095] As Figure 4 In ACT7, the processor 1771 confirms whether a response has been received from the wireless tag TA.

[0096] When the reflected wave from the radio tag TA, modulated according to various data, reaches the antenna 174, the received signal corresponding to the reflected wave is output from the antenna 174, amplified by the receiving amplifier 175, and demodulated by the demodulation unit 176. Then, the demodulated data is provided to the control unit 177. Thus, when the response data sent by the radio tag TAB as described above is provided from the demodulation unit 176 to the control unit 177, if the processor 1771 can correctly receive the response data, it determines YES in ACT7 and proceeds to ACT8.

[0097] As ACT8, processor 1771 sends an ACK command (response to receive command sending unit). The sending of this ACK command is... Figure 6 The event EAD in the code. The ACK command is used to notify the radio tag TA that response data has been received. Then, upon receiving the ACK command, the tag control unit of the radio tag TA sends notification data. The radio tag TA includes the identification code stored in its built-in tag memory in the notification data (identification code sending unit). In short, the notification data is used to notify the identification code. Figure 6 In the example, the ACK command sent in event EAD is a notification for the wireless tag TAB. Then, the wireless tag TAB, as an event EBB, sends notification data containing the identification code "3008 33B2 DDD9 01400000 0000". After sending the notification data, the tag control unit of the wireless tag TAB goes into standby mode to receive the Write command.

[0098] As Figure 4 In ACT9, the processor 1771 obtains the notification data demodulated by the demodulation unit 176.

[0099] As ACT10, processor 1771 sends a Write command. The sending of this Write command is... Figure 6 The event EAE occurs within the process. Processor 1771 will include one of the multiple rewritten identification codes contained in the setup data obtained in ACT1 in the Write command. The Write command is used to request the rewriting of the identification code, equivalent to a third command. Furthermore, processor 1771 performs information processing based on the rewriting program PRA, thus functioning as a rewriting unit.

[0100] The wireless tag TA, which sent notification data as a trigger for the Write command, waits to receive the Write command. Upon receiving the Write command, the tag control unit rewrites the identification code (first identification code) stored in the built-in tag memory into a rewritten identification code (second identification code) included in the Write command (second identification code storage unit). Figure 6 In the example, the wireless tag TAB accepts the Write command sent in the event EAE and rewrites the identification code to "3010 2EDA F110 F040 0000 0001" contained in the Write command.

[0101] Furthermore, although the processor 1771 actually sends a Write command in accordance with the ISO / IEC 18000-6 Type C standard, after sending the ReqRN command and confirming the response from the radio tag TA to the ReqRN command, detailed descriptions and illustrations of this process are omitted here.

[0102] As Figure 4 In ACT11, processor 1771 decrements the value of variable M by 1 (updates). ACT11 is the first counter update unit. In ACT12, processor 1771 checks whether the rewriting related to all wireless tags (TAs) installed on the printing medium, which is the object of image formation, has ended (rewriting completion determination unit). For example, if variable M is greater than or equal to "1", processor 1771 determines it as NO, indicating that the rewriting has not ended, and proceeds to ACT13.

[0103] As ACT13, processor 1771 subtracts 1 from the value of variable N (updates). ACT13 is the second counter update unit.

[0104] As in ACT14, processor 1771 checks whether the loop has ended (limited number of attempts completion judgment unit). Here, the loop is defined as the period during which the trial of tag detection is repeated a predetermined number of times. For example, if the variable N is greater than or equal to "1", processor 1771 determines NO as if the loop has not ended and proceeds to ACT15 (request unit). If the variable N is "0", since the loop has ended, it proceeds to ACT4 (selection unit).

[0105] As ACT15, processor 1771 sends a QueryRep command (request section). The QueryRep command is also one of the second commands. The sending of this QueryRep command is... Figure 6The QuaryRep command is received by each RFID tag (TAA-TAE) as part of the EAF event. However, for RFID tags (TA) that have already received a response to a Query command or QueryRep command after receiving a Select command, this QueryRep command is ignored. When the tag control unit of RFID tag (TA) receives the QueryRep command, it determines whether to send response data. Specifically, it determines whether the response completion flag, indicating that response data has been sent, is "1" or "0" (response completion determination unit). If the response completion flag is "1", the response is complete, and therefore RFID tag (TAB) ignores the QueryRep command sent as part of the EAF event.

[0106] When the tag control unit of a non-responding RFID tag TA receives a QueryRep command, it decrements the counter value CV by one (third counter setting unit). Then, when the decremented counter value CV of RFID tag TA is "0", it sends response data to notify the random number RN. RFID tags TAA, TAC~TAE set their counter value CV to "2", "2", "1", and "3" respectively according to the event EAF. Therefore, if none of the counter values ​​CV of RFID tags TAA, TAC~TAE are "0", no response data is sent.

[0107] If processor 1771 sends a QueryRep command, it returns to Figure 4 In ACT7, processor 1771, for example, sends a QueryRep command and waits for a preset standby time. If no response data is received, it is determined as no response in ACT7, skipping ACT8 to ACT12 and proceeding to ACT13, repeating the processing after ACT13 as described above. Thus, even without a response from the wireless tag TA, processor 1771 also decrements the value of variable N by 1 in ACT13 (updates). ACT13 is the second counter update unit. Then, if processor 1771 still has not ended the loop and determines NO in ACT14, it repeats the processing after ACT15 as described above. Therefore, as... Figure 7 In response to the event EAG, processor 1771 sends a QueryRep command. Wireless tags TAA, TAC~TAE, based on this event EAG, change their counter values ​​CV to "1", "1", "0", and "2". Therefore, wireless tag TAD, because its counter value CV is "0", is considered... Figure 7 In the EBC event, it sends response data containing "AD" data indicating that it is itself (a random number RN). It can continue rewriting the identification code even if there is no response from the wireless tag TA.

[0108] Subsequently, following the same process as described above—acceptance of the ACK command as event EAH, acceptance of notification data as event EBD, and acceptance of the Write command as event EAI—the wireless tag TAD rewrites its identification code to “30102EDA F110 F040 0000 0002”.

[0109] Next, as Figure 8 In event EAJ, processor 1771 sends a QueryRep command. Wireless tags TAA, TAC, and TAE, based on event EAJ, set their counter values ​​CV to "0", "0", and "1" respectively. Therefore, wireless tag TAA, because its counter value CV is "0", sends response data containing "AA" indicating its own random number RN as event EBE. Similarly, wireless tag TAC, because its counter value CV is "0", sends response data containing "AC" indicating its own random number RN as event EBF. Events EBE and EBF occur almost simultaneously. Therefore, as event EAK, a conflict occurs in the response data generation in processor 1771, and neither response data is correctly obtained. Therefore, processor 1771 considers there to be no response and determines it as NO in ACT7.

[0110] Next, as Figure 9 In event EAL, processor 1771 sends a QueryRep command. Based on event EAL, wireless tag TAE sets its counter value CV to "0". Therefore, because its counter value CV is "0", wireless tag TAE sends response data containing its own random number RN as event EBG. Furthermore, wireless tags TAA and TAC, having already sent response data, have their response completion flag set to "1". Therefore, they do not send response data.

[0111] Next, following the same process as described above—acceptance of the ACK command as event EAM, acceptance of notification data as event EBH, and acceptance of the Write command as event EAN—the wireless tag TAE rewrites the identification code to “3010 2EDAF110 F040 0000 0003”.

[0112] Subsequently, although processor 1771 repeated in Figure 4In ACT15, the QueryRep command is sent, but because neither the radio tag TAA nor the radio tag TAC sends response data, the rewriting is not completed and is judged as NO in ACT12. Then, when the processor 1771 repeats sending the Query and QueryRep commands a limited number of times, in ACT13, the processor 1771 changes the variable N to "0". For example, if the variable N becomes "0", then in ACT14, it is judged as YES as the loop has ended, and returns to ACT4, repeating the processing after ACT4 in the same way. In short, the processor 1771 starts a new loop. That is, when the variable N is 5, the number of times one loop is repeated is five.

[0113] Then, as Figure 10 In event EAO, processor 1771 sends the same Select command as event EAB, and also sends a Query command as event EAP. The Select and Query commands are received by each radio tag from TAA to TAE.

[0114] However, because the identification codes of wireless tags TAB, TAD, and TAE have been rewritten and their mask patterns are inconsistent, the Query command is ignored. Wireless tags TAA and TAC, because they have identification codes consistent with their mask patterns, generate counter values ​​CV of "0" and "1" respectively based on the EAP event.

[0115] Since the wireless tag TAA has determined that the counter value CV is "0", it sends response data containing "AA" which represents its own random number RN as an event EBI.

[0116] Subsequently, similar to the above, after receiving the ACK command as event EAQ, the notification data as event EBJ, and the Write command as event EAR, the radio tag TAA rewrites its identification code to "3010 2EDAF110 F040 000 0004". In one loop, the number of times a radio tag TA sends its response data is limited to once. Therefore, even with an increased number of radio tags TA, response data collisions can be reduced.

[0117] Next, as Figure 11 In event EAS, processor 1771 sends a QueryRep command. Based on this event EAS, the wireless tag TAC sets its counter value CV to "0". Therefore, because the counter value CV becomes "0", the wireless tag TAC sends response data containing "AC" representing its own random number RN as event EBK.

[0118] Subsequently, following the same process as described above—acceptance of the ACK command as event EAT, acceptance of notification data as event EBL, and acceptance of the Write command as event EAU—the wireless tag TAC rewrites the identification code to “3010 2EDAF110 F040 0000 0005”.

[0119] As explained above, processor 1771 repeatedly sends the Query command and the QueryRep command. Furthermore, by performing information processing based on the rewritten program PRA, processor 1771 functions as a control unit for repeatedly sending the Query command and QueryRep command as the second command (request unit). Additionally, the function of the control unit may also include sending the Select command again when the predetermined number of repetitions is reached (selection unit).

[0120] After all the identification codes for wireless tags TAA~TAE have been rewritten, processor 1771 changes variable M to "0" in ACT11. Thus, for example, if variable M becomes "0", processor 1771 determines that the rewriting is complete as YES in ACT12 and proceeds to ACT16.

[0121] As ACT16, processor 1771 stops radio wave transmission. For example, processor 1771 stops outputting a transmission signal to modulation unit 171. Then, processor 1771 terminates the rewrite process.

[0122] In the multifunction device 1 described above, the tag transmitting unit 17 selectively and sequentially rewrites the identification codes of the wireless tags TAA to TAE via communication. Therefore, the tag communication unit 17 can communicate with the wireless tags TAA to TAE simultaneously, and can be implemented with a simpler configuration compared to situations requiring mechanical measures such as configuring radio wave shielding components.

[0123] Furthermore, in the multifunction printer 1, the setting data containing the mask pattern specified by the operator is included in the setting file FIA ​​and stored in the auxiliary storage unit 12. The setting data of the setting file FIA ​​is stored in the storage unit 1772 of the communication unit 17 via the interface 178 and applied to the rewrite process. Therefore, when there are multiple different types of tagged labels with different identification codes pre-set on the installed wireless tags TA, the mask pattern can be pre-set according to which of these tagged labels will be used as the printing medium, thereby enabling proper operation.

[0124] This embodiment can be various variations, as follows.

[0125] In the above embodiments, the Select command from ISO / IEC 18000-6 Type C is used as the first command, the Query and QueryRep commands as the second commands, and the Write command as the third command. However, it is also possible to use ISO / IEC 18000-6 Type C as a basis, while replacing at least one of the Select, Query, QueryRep, and Write commands with a partially modified command, or other commands. Alternatively, it is also possible to comply with standards other than ISO / IEC 18000-6 Type C, using commands completely different from the Select, Query, QueryRep, and Write commands as the first to third commands.

[0126] The mask pattern can also be a fixed mask pattern that uses a code pre-set by, for example, the designer of the multifunction printer 1.

[0127] The wireless tag (TA) that is the object of the rewriting of the identification code does not necessarily need to be installed on the printing medium; it can be in any state. Furthermore, the tag communication device of this invention can be mounted on any device other than the multifunction printer 1, and can also be implemented as an independent tag communication device whose main function is to rewrite the identification code of the wireless tag (TA).

[0128] The functions implemented by the processor 1771 through information processing can be partially or entirely implemented by hardware that performs non-program-based information processing, such as logic circuits. Furthermore, each of the aforementioned functions can also be implemented by combining software control with the aforementioned hardware, such as logic circuits.

[0129] While several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, etc., can be made without departing from the spirit of the invention. Furthermore, these embodiments and their variations are all included within the scope or spirit of the invention, and are included within the scope of the invention as described in the claims and their equivalents.

Claims

1. A tag communication device having a communication section that performs wireless communication with a plurality of wireless tags each storing in a tag memory a first identification code containing at least a part of a known common part, the wireless tags comprising: The mask pattern storage unit stores the mask pattern contained in the first command in the tag memory when it receives the first command sent through the selection unit. The response completion determination unit determines whether to send response data when it receives a second command sent through the request unit. The response data sending unit ignores the second command if the response completion determination unit determines that response data has been sent; if it determines that no response data has been sent, it sets the value of a third counter if the first identification code matches the mask pattern; and sends the response data if the value of the third counter is a preset value. The response completion information setting unit sets information indicating that the response data has been sent if the response data sending unit has sent the response data. The identification code sending unit sends notification data containing the first identification code when it receives a response reception command sent through the response reception command sending unit. The tag communication device is characterized by including: a second identification code storage unit, which, upon receiving a third command sent via the rewriting unit, rewrites the first identification code into a second identification code contained in the third command. The first counter setting unit sets a first counter value corresponding to the number of the plurality of wireless tags; The selection unit sends a first command from the communication unit, the first command being used to designate at least a portion of the common part as a mask pattern and to notify the selection of a wireless tag having a first identification code containing the mask pattern; The second counter setting unit sets a limit on the number of times a second command for requesting response data from a selected wireless tag is repeatedly sent; The request unit sends the second command from the communication unit; The response receiving command sending unit, after sending the second command, sends a response receiving command requesting the first identification code if the response data is received within a specified time. Upon receiving the first identification code, the rewriting unit sends a third command from the communication unit to the wireless tag that sent the first identification code, requesting the rewriting of the first identification code and including a second identification code different from the mask pattern. The first counter update unit updates the value of the first counter when the rewrite unit's processing is executed; The second counter update unit updates the second counter if it does not receive the response data and if it determines, based on the updated value of the first counter, that the rewriting of all wireless tags has not been completed; and The control unit determines whether the predetermined number of times has been reached based on the value of the second counter. If the predetermined number of times has been reached, the selection unit's processing of sending the first command is executed again. If the predetermined number of times has not been reached, the request unit's processing of sending the second command is executed again.

2. The tag communication device according to claim 1, wherein, Each time the rewriting unit sends a third command, it requests to rewrite the code to a different second identification code.

3. A tag communication system comprising a plurality of wireless tags and a tag communication device, wherein each wireless tag stores a first identification code in a tag memory, the code comprising at least a known common portion, and the tag communication device has a communication unit for wirelessly communicating with the wireless tags, the tag communication system being characterized in that... The tag communication device includes: The first counter setting unit sets a first counter value corresponding to the number of the plurality of wireless tags; The selection unit sends a first command from the communication unit, the first command being used to designate at least a portion of the common part as a mask pattern and to notify the selection of a wireless tag having a first identification code containing the mask pattern; The second counter setting unit sets a limit on the number of times a second command for requesting response data from a selected wireless tag is repeatedly sent; The request unit is used to send the second command from the communication unit; The response receiving command sending unit, after sending the second command, sends a response receiving command requesting the first identification code if the response data is received within a specified time. Upon receiving the first identification code, the rewriting unit sends a third command from the communication unit to the wireless tag that sent the first identification code, requesting the rewriting of the first identification code and including a second identification code different from the mask pattern. The first counter update unit updates the value of the first counter when the rewrite unit's processing is executed; The second counter update unit updates the second counter if it does not receive the response data and if it determines, based on the updated value of the first counter, that the rewriting of all wireless tags has not been completed. as well as The control unit determines whether the predetermined number of times has been reached based on the value of the second counter. If the predetermined number of times has been reached, the processing of the selection unit that sends the first command is executed again. If the predetermined number of times has not been reached, the processing of the request unit that sends the second command is executed again. The wireless tag includes: The mask pattern storage unit stores the mask pattern contained in the first command in the tag memory when it receives the first command sent through the selection unit. The response completion determination unit determines whether to send the response data when it receives the second command sent through the request unit. The response data sending unit ignores the second command if the response completion determination unit determines that response data has been sent, and if it determines that no response data has been sent, it sets the value of the third counter if it has the first identification code that matches the mask pattern. If the value of the third counter is a preset value, it sends the response data. The response completion information setting unit sets information indicating that the response data has been sent when the response data sending unit has sent the response data. The identification code sending unit, upon receiving a response receiving command sent via the response receiving command sending unit, sends notification data containing the first identification code; and The second identification code storage unit, when receiving the third command sent through the rewriting unit, rewrites the first identification code into a second identification code included in the third command.

4. The tag communication system according to claim 3, wherein, The tag communication device stops transmitting radio waves when it determines that the rewriting of all wireless tags has been completed based on the value of the first counter updated by the first counter update unit.

5. The tag communication system according to claim 3, wherein, When the wireless tag sets the value of the third counter, it randomly determines a value within a preset range.

6. The tag communication system according to claim 3, wherein, Each time the rewriting unit sends a third command, it requests to rewrite the code to a different second identification code.

7. The tag communication system according to claim 3, wherein, The label communication device is disposed within the image forming apparatus, which forms an image on a printing medium comprising multiple labels. The wireless tags are respectively installed on the plurality of labels on the printing medium.

8. A storage medium storing an information processing program that enables a processor disposed in a tag communication device comprising a communication unit for wirelessly communicating with a plurality of wireless tags, each containing a first identification code having at least a known common portion stored in a tag memory, to function as an information processing unit for the following units: the wireless tags comprising: The mask pattern storage unit stores the mask pattern contained in the first command in the tag memory when it receives the first command sent through the selection unit. The response completion determination unit determines whether to send response data when it receives a second command sent through the request unit. The response data sending unit ignores the second command if the response completion determination unit determines that response data has been sent; if it determines that no response data has been sent, it sets the value of a third counter if the first identification code matches the mask pattern; and sends the response data if the value of the third counter is a preset value. The response completion information setting unit sets information indicating that the response data has been sent if the response data sending unit has sent the response data. The identification code sending unit sends notification data containing the first identification code when it receives a response reception command sent through the response reception command sending unit. And a second identification code storage unit, which, upon receiving a third command sent through the rewriting unit, rewrites the first identification code into a second identification code included in the third command, each unit comprising: The first counter setting unit sets a first counter value corresponding to the number of the plurality of wireless tags; The selection unit sends a first command from the communication unit, the first command being used to designate at least a portion of the common part as a mask pattern and to notify the selection of a wireless tag having a first identification code containing the mask pattern; The second counter setting unit sets a limit on the number of times a second command for requesting response data from a selected wireless tag is repeatedly sent; The request unit is used to send the second command from the communication unit; The response receiving command sending unit, after sending the second command, sends a response receiving command requesting the first identification code if the response data is received within a specified time. Upon receiving the first identification code, the rewriting unit sends a third command from the communication unit to the wireless tag that sent the first identification code, requesting the rewriting of the first identification code and including a second identification code different from the mask pattern. The first counter update unit updates the value of the first counter when the rewrite unit's processing is executed; The second counter update unit updates the second counter if it does not receive the response data and if it determines, based on the updated value of the first counter, that the rewriting of all wireless tags has not been completed; and The control unit determines whether the predetermined number of times has been reached based on the value of the second counter. If the predetermined number of times has been reached, the selection unit's processing of sending the first command is executed again. If the predetermined number of times has not been reached, the request unit's processing of sending the second command is executed again.

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