JP4461853B2 - Image forming apparatus and communication control method - Google Patents

Description

  The present invention relates to an image forming apparatus to which a plurality of replacement parts to which a non-contact IC tag is attached is mounted, and in particular, writing data to and / or data from the non-contact IC tag of the mounted replacement part. The present invention relates to a communication mechanism for reading data.

  Conventionally, as a non-contact type information storage medium, a non-contact IC tag (also referred to as an RFID (Radio Frequency IDentification) tag) that operates using power obtained from a received high-frequency signal as a power source has been used. Supply of power to the non-contact IC tag and reading and writing of information are performed by a reader / writer via a wireless space.

  As an example to which such a non-contact IC tag and a reader / writer are applied, an image forming apparatus main body such as a color copying machine (hereinafter referred to as “copying machine”) or a color printer, and a toner cartridge mounted on the image forming apparatus main body. There is a system consisting of replacement parts. In this system, communication is performed between a reader / writer mounted on a copying machine main body and a non-contact IC tag mounted on a toner cartridge.

  Copiers may improve functions such as maintaining image quality by managing information on consumable parts such as toner cartridge consumption and remaining amount. For example, the copying machine has toner cartridges for four colors of yellow (Y), magenta (M), cyan (C), and black (K) (hereinafter referred to as “four colors of YMCK”). The remaining amount of toner is stored and held in a non-contact IC tag mounted on the toner cartridge.

  First, when the power is turned on, the reader / writer installed in the copier establishes communication by reading the tag ID stored and held in the non-contact IC tag installed in one toner cartridge. Thereafter, the toner remaining amount information stored and held in the non-contact IC tag is read. By sequentially performing this communication for the non-contact IC tags of the four toner cartridges, it is possible to detect the toner remaining amount of each toner cartridge. This can be notified to the user. Further, every time a print job occurs, the copying machine calculates the remaining amount of toner in each toner cartridge from the amount of use of each color by the job. Then, the reader / writer writes the update information in the non-contact IC tag of the toner cartridge as the update information using the calculated remaining toner amount (update). Therefore, the updated toner remaining amount is always stored and held in the non-contact IC tag.

  Therefore, the user can grasp the toner remaining amount of each toner cartridge through a display or the like mounted on the copying machine. Even if the toner cartridge of the copying machine is replaced with a new one or the ink toner cartridge is replaced between copying machines, the remaining amount of ink information is stored and held in each non-contact IC tag. Therefore, the ink remaining amount information of the ink / toner / cartridge can be grasped by reading the ink remaining amount information from the reader / writer.

  Although the toner cartridge has been exemplified above, there are many cases in which other replacement parts such as the photosensitive drum cartridge are provided with a non-contact IC tag so that necessary information can be read and written. In this case, since there are four toner cartridges and four drum cartridges in the tandem color machine, a reader / writer mechanism corresponding to at least a total of eight non-contact IC tags is required. For this, the simplest is to provide a reader / writer for each non-contact IC tag (replacement part), but this increases the cost.

  As one solution to this, Patent Document 1 discloses an image in which only an antenna is provided for each non-contact IC tag, and a circuit mechanism for reading / writing control and signal transmission / reception is shared by one. A forming apparatus is disclosed. In this apparatus, a switch is provided between the circuit mechanism and the antenna group, and one antenna (non-contact IC tag for reading and writing) that transmits and receives is selected by this switch.

  Incidentally, although not related to the image forming apparatus, Patent Documents 2 and 3 provide a plurality of antennas for communicating with a transponder and a non-contact type information storage medium, and by switching between the plurality of antennas, 1 A device for transmitting and receiving signals with two RF controllers and a read / write device is shown.

JP 2002-49283 A JP-A-6-281747 JP 2001-52124 A

  In the above-described tandem type color copying machine, for example, update data is written into toner cartridges and drum cartridges of C, M, Y, and K colors each time one print job is completed. In this case, in order to avoid problems such as interference, writing is performed for each cartridge while switching the antenna to be used one by one. At this time, if the configuration of Patent Document 1 is taken, each time writing is performed on one cartridge, an antenna corresponding to the cartridge is selected by a switch, and a standard (for example, ISO14443) with a non-contact IC tag is selected. After communication establishment processing such as anti-collision is performed, update data is written.

  As described above, in the apparatus of Patent Document 1, it is necessary to perform a communication establishment operation as many times as the number of data communication when a print job is continuously generated, and the system operation speed such as the communication speed and the printing speed is improved. It was an issue. Further, some non-contact IC tags require a large amount of power during communication establishment operation compared to data communication. When such a tag is used, an error is likely to occur due to insufficient power during the communication establishment operation. If an error occurs, it will start over from the beginning, and communication will take more time. For this reason, if the number of tags that have to be communicated for each job, such as a color machine, is increased, it takes time for communication for each job. This method was difficult to apply.

  Also, Patent Document 2 and Patent Document 3 share a circuit mechanism for read / write control and small signal reception similarly to Patent Document 1 with a plurality of antennas. Even if it is applied to a forming apparatus, the same problem as in Patent Document 1 appears.

The image forming apparatus according to the present invention is an image forming apparatus capable of mounting a replacement part to which a non-contact IC tag is attached, and is provided close to the mounting position of each replacement part in the image forming apparatus, An antenna for communicating with a contactless IC tag of a replacement part mounted at a corresponding mounting position, a carrier wave generating means for generating a carrier wave signal, and the carrier signal by a data signal to be transmitted to the contactless IC tag. modulating means for modulating, when communicating with the noncontact IC tag of any replacement part, the replacement part of the antenna which are provided proximate the the mounting position of the replacement part in the image forming apparatus Is selected, and the output of the modulation means is supplied to the selected antenna for transmission, and the antenna group not selected is And a transmission control means for transmitting to supply a carrier signal.

  According to this configuration, since a carrier wave is output from an antenna other than the antenna that performs data communication with the corresponding contactless IC tag, the contactless IC tag that does not perform communication during the communication. Is also receiving power. Here, considering the case where communication with a non-contact IC tag is completed and communication with another non-contact IC tag is performed, if the latter is in a power-off state as in the case of a conventional device, then there is In order to shift from the state to the state where communication is possible, an initialization routine and a communication establishment operation according to the standard of the non-contact IC tag are required, and a considerable time is required. On the other hand, in the configuration of the present invention, since the latter is already supplied with power at that time, the period until communication with the latter can be started can be made shorter than before. In particular, once communication is established between the transmission control means and each non-contact IC tag, the communication establishment state can be maintained unless power is supplied to the non-contact IC tag. A communication partner can be quickly switched from a non-contact IC tag to another non-contact IC tag.

  In a preferred aspect of the present invention, the transmission control means supplies and transmits the carrier signal to all the antennas when not communicating with any non-contact IC tag of any replacement part. .

  In this aspect, even when communication is not performed with any non-contact IC tag, power can be continuously supplied to these non-contact IC tags, so that it is necessary to communicate with any non-contact IC tag thereafter. Communication can be started quickly.

  In another preferred aspect of the present invention, the modulation means includes a modulation circuit connected to the antenna corresponding to each of the plurality of antennas, and each of the modulation circuits is a common carrier wave generation means. When the data signal is input from the carrier signal, the modulated signal obtained by modulating the carrier signal with the data signal is obtained. When the data signal is not input, the unmodulated carrier wave is obtained. A signal is supplied to the connected antenna, and the transmission control means supplies a data signal to the modulation circuit connected to the selected antenna, and data is sent to the modulation circuit connected to the other antenna. Control not to supply a signal.

  According to this aspect, since the carrier wave generating means and the transmission / reception control means can be shared by a plurality of antennas, the circuit scale can be reduced and cost reduction can be expected.

  In another preferred aspect, the transmission control means includes a switch for selectively supplying one of the output of the carrier wave generation means and the output of the modulation means to the antenna for each antenna. The switch corresponding to the selected antenna selects the output of the modulation means, and the switch corresponding to each of the antenna groups not selected causes the output of the carrier wave generation means to be selected.

  According to this aspect, in addition to the carrier wave generation means and the transmission / reception control means, the modulation means can be shared by the plurality of antennas.

  Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be described with reference to the drawings.

  FIG. 1 schematically shows a main part of an image forming apparatus according to the present invention, that is, a replacement part and a reader / writer mechanism for reading and writing data with respect to a non-contact IC tag provided in the replacement part. FIG. Here, the image forming apparatus is an apparatus having a mechanism for printing an image on paper, such as a printer, a copier, a facsimile machine, or a digital copier. There are various printing methods such as an electrophotographic method and an inkjet method, but the present invention does not depend on such a method.

  This image forming apparatus includes an image forming apparatus main body 100 and replacement parts 200a to 200d (collectively referred to as replacement parts 200 as appropriate). The image forming apparatus main body 100 is a substantially fixed part of the image forming apparatus such as a housing, a display for a user interface, and buttons. The replacement part 200 is a unit that can be attached to and detached from the image forming apparatus main body 100 and is replaced when worn. Examples of the replacement part 200 include a toner cartridge, a photosensitive drum cartridge, a developing unit, and a fixing unit. In this example, four replacement parts 200a to 200d are illustrated. However, for example, four toner cartridges of C, M, Y, and K may be recalled. In addition to this, for example, when a non-contact IC tag is also provided on the photosensitive drum cartridge, the number of replacement parts is eight.

  Non-contact IC tags 210a-210d (referred to as non-contact IC tags 210 as appropriate) are attached to the replacement parts 200a-d, respectively. This non-contact IC tag 210 stores management data such as a consumption amount of the replacement part 200 (how many sheets were used for printing the part, etc.) and parameters for image quality control for improving image quality. Used as a storage device. The non-contact IC tag 210 includes a nonvolatile memory for storing management data, a circuit for reading and writing to the nonvolatile memory, an antenna and a transmission / reception circuit for communicating with a reader / writer mechanism on the image forming apparatus main body 100 side. ing.

  There are various types of contactless IC tag systems such as contact type, proximity type, and proximity type. Considering the size of the image forming device, the degree of freedom of the layout of the reader / writer mechanism, radio wave regulations, etc. In this case, a proximity type (ISO14443) having a communication distance of about 10 cm or less is used.

  There are several types of proximity type non-contact IC tags such as A type and B type, and any of them may be adopted.

  The image forming apparatus main body 100 is mounted with a main board 110, an RF control circuit board 120, and antenna boards 150a to 150d (referred to collectively as an antenna board 150 as appropriate).

  The main substrate 110 is a substrate on which a CPU (Central Processing Unit) 112 that performs overall control of the image forming apparatus is mounted. The RF control circuit board 120 is a board on which a circuit for reading and writing data with respect to the non-contact IC tag 210 of each replacement part 200 is mounted. The antenna boards 150a to 150d are boards on which antennas 152a to 152d for reading and writing data with respect to the non-contact IC tags 210a to 210d are mounted. Each antenna substrate 150 is disposed in the image forming apparatus main body 100 at a position close to the mounting portion of the corresponding replacement part 200. Since the RF control circuit board 120 and the antenna boards 150a to 150d are connected by signal line harnesses, the antenna boards 150a to 150d are arranged in the vicinity of the replacement parts 200a to 200d by routing the harnesses. It can be arranged at an appropriate position where it can communicate with the corresponding non-contact IC tags 210a to 210d. Similarly, the main board 110 and the RF control circuit board 120 are also connected by a signal line harness. Here, the configuration in which the RF control circuit board 120 and the main board 110 are separated is illustrated, but this is merely an example. The antenna 152 must be in a position close to the replacement part 200, but the RF control circuit or the like is not necessary, so each circuit on the RF control circuit board 120 may be provided on the main board 110. Further, the antenna 152 may be provided on the RF control board 120 by devising the shape of the board according to the position of the non-contact IC tag of the replacement part.

  Next, each circuit on the RF control circuit board 120 will be described.

  First, the RF control circuit 122 is a circuit in charge of a logic part of a general reader / writer mechanism for reading and writing data with respect to each contactless IC tag 210. That is, the RF control circuit 122 communicates with the non-contact IC tag 210 by controlling the carrier wave generation circuit 124, the modulation circuit 128, the switching circuit 132, the reception circuit 136, and the like in accordance with an instruction from the CPU 112.

  The carrier wave generation circuit 124 is a circuit that generates a carrier wave signal for communication. When the non-contact IC tag 210 conforming to the ISO14443 standard is used, a 13.56 MHz carrier wave signal is generated according to the standard. The carrier wave generation circuit 124 is connected in parallel to the plurality of modulation circuits 128a to 128d via the switch 126.

  The switch 126 is controlled by the RF control circuit 122. When the switch 126 is closed, the carrier signal output from the carrier generation circuit 124 is supplied to all the modulation circuits 128a to 128d.

  The modulation circuits 128a to 128d (collectively referred to as the modulation circuit 128 as appropriate) are connected to the switching circuit 132 through signal lines, and the RF control circuit is connected to the modulation circuits 128a to 128d. A data signal is received from 122, and the carrier signal supplied from the carrier generation circuit 124 is modulated with this data signal. In the case of a system compliant with ISO14443, the modulation circuit 128 at this time generates a modulated signal of ASK (amplitude shift) modulation as shown in FIG. The modulation circuits 128a to 128d output an unmodulated carrier wave signal as shown in FIG. 2B when the data signal is not supplied. The outputs of the modulation circuits 128a to 128d are radiated from the corresponding antennas 152a to 152d after being amplified by the corresponding amplifiers 130a to 130d.

  The switching circuit 132 is a circuit that selects the modulation circuit 128 to which the data signal is supplied under the control of the RF control circuit 122. In the present embodiment, only one antenna for transmitting a data signal is selected from the plurality of antennas 152a to 152d connected to one RF control circuit board 120.

  That is, the RF control circuit 122 outputs a data signal to be transmitted to one non-contact IC tag 210 selected as a communication partner to the data signal line to the switching circuit 132 and also serves as a control signal line to the switching circuit 132. On the other hand, a control signal for selecting an output to the modulation circuit 128 corresponding to the selected non-contact IC tag 210 is supplied. By this control, the data signal is supplied only to the modulation circuit 128 corresponding to the non-contact IC tag 210 of the communication partner. Thereby, a data signal can be transmitted to the non-contact IC tag 210 via the corresponding antenna 152. On the other hand, since the carrier wave signal is supplied to all the modulation circuits 128a to 128d as long as the switch 126 is closed, the data signal is transmitted from the corresponding antenna 152 to one non-contact IC tag 210. The other non-contact IC tags 210 each receive a carrier wave from the corresponding antenna 152. Further, even when no data is transmitted to any non-contact IC tag 210, a carrier wave is supplied from each antenna 152 to the corresponding non-contact IC tag 210 if the switch 126 is on.

  A response signal from the non-contact IC tag 210 to the data signal transmitted in this way is received by the corresponding antenna 152. Each antenna 152a-d is connected to a common receiving circuit 136 via diodes 134a-d, respectively. The reception circuit 136 performs general signal processing on the received signal from the non-contact IC tag 210 such as filtering, amplification, detection, and waveform shaping on the signal input from the antenna 152, and outputs the signal of the processing result to the RF Input to the control circuit 122. In this circuit configuration, all the signals received by the antennas 152a to 152d are merged and input to the receiving circuit 136. However, according to the data communication control of this embodiment, the non-contact IC tags 210a to 210d. Since multiple of them do not respond at the same time, problems such as crosstalk hardly occur.

  The configuration of the reader / writer mechanism in the image forming apparatus according to the present embodiment has been described above. Next, operations of the reader / writer mechanism and the non-contact IC tag group will be described with reference to FIG.

  When the image forming apparatus main body 100 is powered off, all the non-contact IC tags 210a to 210d are in a power off state. When the power supply of the main body 100 is turned on, power is supplied to the main board 110 and the RF control circuit board 120, whereby each circuit such as the CPU 112 and the RF control circuit 122 is activated. As part of this startup processing routine, the CPU 112 gives a carrier ON instruction to the RF control circuit 122, and in response to this, the RF control circuit 122 turns on the switch 126 (S100). Thereby, the carrier wave signal generated by the carrier wave generation circuit 124 is supplied to the modulation circuits 128a to 128d, amplified by the amplifiers 130a to 130d, and then radiated from the antennas 152a to 152d.

  Thereby, the non-contact IC tags 210a to 210d of the replacement parts 200a to 200d attached to the image forming apparatus main body 100 receive the carrier waves from the corresponding antennas 152a to 152d, respectively, and start operation using the power of the carrier waves as a power source. Then, a predetermined initialization routine is executed to enter the standby (IDLE) state. Since the initialization routine itself is defined in the standard, its description is omitted.

  On the other hand, the CPU 112 gives a communication establishment processing instruction to the RF control circuit 122 after the carrier wave on instruction. Then, the RF control circuit 122 selects the antennas 152a to 152d (that is, the modulation circuits 128a to 128d corresponding thereto) for performing communication by controlling the switching circuit 132 one by one (S102), and selects the selected antenna 152. Then, communication with the corresponding non-contact IC tag 210 is established by establishing communication with the tag 210 (S104, S202).

  During this communication establishment process, the RF control circuit 122 supplies the selected modulation circuit 128 with a data signal such as a request necessary for communication establishment and modulates it, and radiates the resulting modulated wave from the antenna 152. Communication is performed by receiving a response signal from the non-contact IC tag 210 via the receiving circuit 136.

  In this communication establishment process, first, a request command (for example, REQA or REQB) or a wakeup command (for example, WUPA or WUPB) is issued from the RF control circuit 122 side, and then an anti-collision (collision prevention) process is performed. When the anti-collision process is completed, the contactless IC tag 210 and the RF control circuit 122 at the position corresponding to the antenna 152 selected in S102 are in a communication established state. By the communication establishment process, the RF control circuit 122 knows the tag ID of the non-contact IC tag 210 and stores it in association with the selected antenna 152. Thereby, the RF control circuit 122 can communicate with the non-contact IC tag 210 by using the tag ID thereafter. The non-contact IC tag 210 shifts to an active (active) state when the communication establishment process is completed.

  By repeating the processes of S102 and S104 for all the antennas 152 connected to the RF control circuit board 120 (S106), communication is established with the tags 210 of all the replacement parts 200 that the board 120 is in charge of. .

  Here, in this embodiment, the carrier signal is supplied to all the modulation circuits 128a to 128d, and the modulation circuit 128 that supplies the data signal is switched one by one, and the supply of the data signal is finished. Only the carrier wave is supplied to the modulation circuit 128. The RF control circuit 122 does not issue a halt (HLT: pause) or deselect (DISELECT: deselect) command to the tag 210 even after the communication establishment process for the non-contact IC tag 210 is completed. The communication with the tag 210 is cut off by stopping the data signal supply to the antenna 152 corresponding to the tag 210. In the device configuration in which a one-to-one correspondence is established between the non-contact IC tag 210 and the antenna 152 as in the present embodiment, there is no problem with such communication control. According to such control, the contactless IC tag 210 once established by communication and in the active state continues to be supplied with power by the carrier without interruption even after the communication establishment process is completed, and maintains the active state.

  In this manner, a state in which communication establishment with all the tags 210 is completed and all the tags 210 are in an active state is referred to as a “communication enabled state” here. While in this communicable state, the RF control circuit 122 performs communication for reading and writing with respect to each non-contact IC tag 210 in accordance with an instruction from the CPU 112.

  When the image forming apparatus main body 100 is turned off in the communicable state, the power supply by the carrier wave to each non-contact IC tag 210 is also cut off, so that all the tags 210 are turned off. And transition.

  Many image forming apparatuses shift to a power saving mode unless they are used for a long time in order to reduce power consumption. When shifting to the power saving mode, it is preferable from the viewpoint of power saving if the switch 126 is turned off to stop the carrier wave output from each antenna 152 (S108). Further, the power supply to the RF control circuit board 120 may be cut off in the power saving mode. In this case, the carrier wave output from each antenna 152 is cut off. Thereby, each non-contact IC tag 210 shifts to a power-off state. Thereafter, when the power saving mode is canceled, the RF control circuit 122 performs the same processing as when the power is turned on, and establishes communication with each non-contact IC tag 210.

  Although not shown in the figure, when the user removes the replacement part 200 from the image forming apparatus main body 100, the non-contact IC tag 210 of the part 200 is out of the operating magnetic field of the corresponding antenna 152. Become. In this case, when the removed replacement part 200 is mounted again on the image forming apparatus main body 100, the CPU 112 that has received the signal from the sensor that has detected the replacement is connected to the RF control circuit 122 with respect to the component 200. A communication establishment operation for the non-contact IC tag 210 may be instructed.

  Next, a communication operation between the reader / writer mechanism and the non-contact IC tag when in a communicable state will be described with reference to FIG.

  When the CPU 112 detects the occurrence of a predetermined event (for example, the end of a print job) that requires data writing or reading with respect to the tag 210 of any replacement part 200, the CPU 112 sends or reads data to the RF control circuit 122. The instructions are given. For example, this instruction includes selection of a target non-contact IC tag 210, type of operation for the tag, data used for the operation (for example, data to be written), parameters (for example, target addresses for writing and reading), etc. Is included. When receiving such an instruction (S110), the RF control circuit 122 generates a data signal indicating a command corresponding to the instruction, and the switching circuit 132 causes the antenna 152 corresponding to the tag 210 selected by the instruction to be generated. By selecting (S112), it communicates with the tag 210 (S114, S210). Thereby, according to the instruction | indication of CPU112, operation with respect to the non-contact IC tag 210 is made. At this time, the RF control circuit 122 simply stops the supply of the data signal to the antenna 152 after the necessary communication according to the instruction is completed, and the supply of the carrier wave signal is continued. Tag 210 remains active.

  The preferred embodiment of the present invention has been described above. In this embodiment, one RF control circuit 122, one carrier wave generation circuit 124, and one reception circuit 136 are required for reading and writing with respect to the plurality of non-contact IC tags 210, so that a reader / writer is provided for each replacement part. Significant cost reduction. Further, since the number of parts is reduced, the mounting area of the board can be reduced, which is advantageous for securing a mounting space.

  In addition, according to the present embodiment, if communication is established with each contactless IC tag 210 first, a carrier wave is always supplied to all contactless IC tags 210 even when data communication is not performed. All the non-contact IC tags 210 can maintain an active state. Therefore, once communication is established with all the non-contact IC tags 210 when the power is turned on or when the power saving mode is released, communication can be started without performing the communication establishment operation unless the power is turned off thereafter. Therefore, when communication is performed again with the tag 210 once communication is completed, communication can be performed quickly compared to the conventional case where communication is established each time. In addition, when communicating with a plurality of non-contact IC tags 210 in accordance with the procedure, conventionally, after communication with one tag 210 was completed, it was necessary to establish communication to communicate with the next tag. However, in the present embodiment, such a need is eliminated, and the communication time can be shortened. For example, in a configuration in which update data is written to tags of various replacement parts of a toner cartridge and a drum cartridge every time a print job is completed, these various cartridges exist for each color of CMYK in a color copying machine. Since a very large number of tags must be communicated between the end of a print job and the start of the next print job, the time reduction effect according to the present embodiment is extremely important.

  In the present embodiment, at most one of the plurality of antennas 152 performs data communication, and the remaining antennas only radiate a carrier wave for the data communication. In general, there is a possibility of mutual interference when a plurality of “antenna-tag” pairs are in close proximity to each other. However, in this embodiment, even if the antennas 152 are close to each other, communication is performed as described above. Since there is only one and the rest only outputs a carrier wave, there is almost no interference. Further, in the configuration of the present embodiment, the positional relationship between each antenna 152 and its counterpart tag is fixed, and they can be brought close enough by the layout design. Therefore, the transmission output from each antenna 152 is general. It can be weaker than the reader / writer of the application. For this reason, there is little possibility of mutual interference and interference. Further, for the sake of completeness, the area including each “antenna-tag” pair can be shielded with a metal plate, a metal mesh, or the like.

  Next, a circuit configuration of a modified example will be described with reference to FIG. In FIG. 5, elements corresponding to those shown in FIG. In the figure, the display of the amplifier for the transmission signal is omitted in order to avoid complexity. This amplifier may be provided between the switch 142 and the antenna 152 corresponding thereto, for example. In addition, since the receiving-related circuit configuration including the receiving circuit 136 may be the same as that in FIG. 1, a part of the illustration is omitted in FIG.

  In the embodiment of FIG. 1, the RF control circuit 122, the carrier wave generation circuit 124, and the reception circuit 136 are made common to the plurality of antennas 152, but the modulation circuit 128 is provided for each antenna 152. On the other hand, in the example of FIG. 5, the modulation circuit 128 is also shared. For this reason, the switch part 140 is provided in this modification. The switch unit 140 includes antennas 152a, b, c. . . Connected to the switches 142a, b, c. . . (Hereinafter collectively referred to as switch 142). Each switch 142 has two input terminals. One input terminal is connected to the output of the carrier wave generation circuit 124 and the other is connected to the output of the modulation circuit 128. The switch 142 selects one of these two input terminals and connects it to the corresponding antenna 152. These switches 142 are switched under the control of the RF control circuit 122.

  That is, when the image forming apparatus main body 100 is turned on, the RF control circuit 122 causes each switch 142 to select the output of the carrier wave output circuit 124 so that the carrier wave is output from each antenna 152. When a data signal is transmitted to any one of the contactless IC tags 210 at the time of communication establishment or subsequent data communication, the RF control circuit 122 supplies the data signal to be transmitted to the modulation circuit 128, and The switch 142 of the antenna 152 corresponding to the non-contact IC tag 210 is switched to the modulation circuit 128 side. The other switches 142 remain selected on the carrier wave generation circuit 124 side. Therefore, the modulation circuit 128 modulates the carrier wave signal supplied from the carrier wave generation circuit 124 with the data signal and outputs it, but the modulation output is transmitted only from the antenna 152 for which the switch 142 selects the modulation circuit 128 side. Thus, the other antennas 152 continue to output a carrier wave. When the data transmission is completed, the RF control circuit 122 switches the switch 142 that has selected the modulation circuit 128 side to the carrier wave generation circuit 124 side again.

  It will be apparent that communication control as shown in FIGS. 3 and 4 can also be realized in the circuit configuration of such a modification.

  Next, a further modification will be described with reference to FIG. In FIG. 6, elements corresponding to the elements shown in FIG.

  In the modification of FIG. 6, each antenna substrate 160a, b. . . (Collectively referred to as antenna substrate 160), antennas 162a, b. . . (Generically called antenna 162), carrier wave generating circuits 164a, b. . . (Generally called carrier wave generation circuit 164), modulation circuits 166a, b. . . (Generically referred to as modulation circuit 166), receiving circuits 168a, b. . . (Receiving circuit 168 generically) is mounted, and only the RF control circuit 122 is mounted on the RF control circuit board 120. The RF control circuit 122 has a plurality of output ports, and a signal line harness extending to the antenna substrate 160 is connected to each of the ports.

  In this configuration, while the image forming apparatus main body 100 is powered on, a carrier wave is output from each antenna 162 even when communication with the tag 210 is not performed.

That is, when the power of the image forming apparatus main body 100 is turned on, the modulation circuit 166 of all the antenna substrates 160 controls the carrier wave supplied from the corresponding carrier wave generation circuit 164 by the control from the RF control circuit 122. Output as it is. As a result, when each non-contact IC tag 210 enters a standby state, the RF control circuit 122 next selects each tag 210 one by one and sequentially performs communication establishment processing. At this time, even if communication establishment for a certain tag 210 is completed, an unmodulated carrier wave is output from the antenna 162 without stopping the operation of the carrier wave generation circuit 164 of the antenna substrate 10 corresponding to the tag 210. When data is transmitted to a certain tag 210 after communication is established, the RF control circuit 122 supplies the data signal to the modulation circuit 166a of the antenna substrate 160 corresponding to the tag 210, and the antenna 162 transmits the data. as modulated wave corresponding to the data signal is transmitted, so that non-modulated carrier wave from Rasono antenna 162 transmission has been completed is output.

  Even in such a configuration, the communication control as shown in FIGS. 3 and 4 can be realized as in the configuration of FIG. 1, so that the same communication time shortening effect as in the configuration of FIG. 1 can be obtained.

  In the modification of FIG. 6, the baseband having a frequency much lower than that of the carrier wave is between the main board 110 and the RF control circuit board 120 and between the RF control circuit board 120 and each antenna board 160. Only the data signal (logic signal) flows, and the high frequency flows only inside each antenna substrate 160. Therefore, for example, even if each antenna board 160 is connected to the RF control circuit board 120 with a long signal line harness so that each antenna board 160 can be laid out freely in the image forming apparatus main body 100, a high-frequency signal is not transmitted to the harness. Does not flow. For this reason, there is an advantage that it is not necessary to perform special consideration for impedance matching and radio wave radiation from the long harness portion.

  5 and 6, the RF control circuit board 120 and the main board 110 can be unified on the same board as in the structure of FIG.

FIG. 3 is a diagram for explaining a configuration of a reader / writer mechanism of the image forming apparatus according to the present invention. It is a figure which shows the mode of the carrier wave and modulation wave which are output from the reader / writer concerning embodiment of this invention. It is a figure for demonstrating the whole operation | movement and state transition of the system which consists of a reader / writer mechanism and a non-contact IC tag group. It is a figure for demonstrating operation | movement of the reader-writer mechanism and non-contact IC tag group in a communicable state. It is a figure which shows another example of a structure of the reader / writer mechanism of an image forming apparatus. It is a figure which shows another example of a structure of the reader / writer mechanism of an image forming apparatus.

Explanation of symbols

  110 main board, 112 CPU, 120 RF control circuit board, 122 RF control circuit, 124 carrier wave generation circuit, 126 switch, 128a-d modulation circuit, 130a-d amplifier, 132 switching circuit, 134a-d diode, 136 receiving circuit, 150a-d antenna substrate, 152a-d antenna, 200a-d replacement parts, 210a-d non-contact IC tag.

Claims (6)

An image forming apparatus in which a plurality of replacement parts to which a non-contact IC tag is attached can be attached and detached,
An antenna for communicating with a non-contact IC tag of a replacement part that is provided in the vicinity of the mounting position of each replacement part in the image forming apparatus and that is mounted at the corresponding mounting position;
Carrier wave generating means for generating a carrier wave signal;
Modulation means for modulating the carrier signal with a data signal to be transmitted to the contactless IC tag;
When communicating with the noncontact IC tag of any replacement part, select the one corresponding to the replacement part of the antenna which are provided proximate the the mounting position of the replacement part in the image forming apparatus And a transmission control means for supplying and transmitting the output of the modulation means to the selected antenna, and for supplying and transmitting the carrier signal to a group of antennas not selected.
An image forming apparatus comprising:   The said transmission control means supplies and transmits the said carrier wave signal with respect to all the said antennas, when not communicating with the non-contact IC tag of any replacement parts. Image forming apparatus. The modulation means includes a modulation circuit connected to the antenna corresponding to each of the plurality of antennas,
Each of these modulation circuits is supplied with a carrier signal from the common carrier generation means, and when a data signal is inputted, modulates the carrier signal with the data signal and converts the modulated signal obtained as a result into data When no signal is input, the unmodulated carrier signal is supplied to the connected antenna,
The transmission control means controls to supply a data signal to a modulation circuit connected to the selected antenna and not to supply a data signal to a modulation circuit connected to another antenna.
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.   The transmission control means includes a switch for selectively supplying one of the output of the carrier wave generation means and the output of the modulation means to the antenna for each antenna, and corresponds to the selected antenna. 3. The image forming apparatus according to claim 1, wherein an output of the modulation unit is selected by a switch that performs the selection, and an output of the carrier wave generation unit is selected by a switch corresponding to each of the antenna groups that are not selected. apparatus. As a receiving circuit for receiving a response wave from the contactless IC tag group, any one of claims 1 to 4, characterized in that it comprises a common receiving circuit connected to the plurality of antennas The image forming apparatus described in 1. When communicating for at least one of reading or writing data to a non-contact IC tag mounted on an image forming apparatus and attached to each replacement part mounted on the image forming apparatus A communication control method,
When a data signal is transmitted to a non-contact IC tag of any replacement part, an antenna corresponding to the replacement part is provided from each antenna provided close to the mounting position of each replacement part in the image forming apparatus. A communication control method for selecting and transmitting a modulated output obtained by modulating a carrier signal with the data signal to a selected antenna and transmitting the carrier signal to an unselected antenna group. .

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