JP2010201791A - Image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem wherein a constitution is complicated due to changing of a communication frequency, movement of an antenna, and movement of a radio wave reflecting member when communication with an RF tag does not succeed. <P>SOLUTION: The image forming device includes a carriage 3 on which a recording head 4 for forming an image on a paper sheet 10 is mounted and which reciprocates in a main scanning direction, an RFID communication control device 41 communicating with the RF tag 40 provided on the paper sheet 10, and the communication antenna 43 provided in a region where an output radio wave can reach the carriage 4. When communication with the RF tag 40 does not succeed, control is performed so that the carriage 3 is moved, the reflection situation of the radio wave is adjusted, and that communication with the RF tag 40 is retried. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus capable of communicating with an RF tag attached to a recording medium.

  As an image forming apparatus such as a printer, a facsimile, a copying apparatus, a plotter, and a complex machine of these, for example, an ink jet recording apparatus or the like is used as an image forming apparatus of a liquid discharge recording method using a recording head that discharges ink droplets as an image forming means. Are known. This liquid discharge recording type image forming apparatus means that ink droplets are transported from a recording head (not limited to paper, including OHP, and can be attached to ink droplets and other liquids). Yes, it is also ejected onto a recording medium or a recording medium, recording paper, recording paper, etc.) to form an image (recording, printing, printing, and printing are also used synonymously). And a serial type image forming apparatus that forms an image by ejecting liquid droplets while the recording head moves in the main scanning direction, and a line type head that forms images by ejecting liquid droplets without moving the recording head There are line type image forming apparatuses using

  In the present application, the “image forming apparatus” of the liquid discharge recording method is an apparatus that forms an image by discharging liquid onto a medium such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, ceramics, or the like. In addition, “image formation” means not only giving an image having a meaning such as a character or a figure to a medium but also giving an image having no meaning such as a pattern to the medium (simply It also means that a droplet is landed on a medium). The “ink” is not limited to what is called ink, and is not particularly limited as long as it becomes a liquid when ejected. For example, a DNA sample, a resist, a pattern material, etc. Is also included. The image forming means used in the image forming apparatus is not limited to a recording head using a liquid discharge head, but the following description will be made on a recording head using a liquid discharge head.

  By the way, an RFID (Radio Frequency Identification) system is known in which information is read and written in a contactless manner by using a wireless communication device and a communication antenna with a small RF tag capable of reading and writing predetermined information. In this RFID system, even when RF tags are fixed to a management object such as a product or a document, and a large number of these tags are collected and the RF tags cannot be seen from the surface, information can be read / written from / to each RF tag by wireless communication. Therefore, practical use is expected in various fields such as article management and inspection processes.

  The RF tag can store and read an ID unique to the tag and management information arbitrary by the user. When article management is performed using these pieces of information, information can be acquired if there is a dedicated reader, but the operator cannot obtain information by viewing the RF tag. For this reason, the RF tag is often used in which information is written while being fixed to a label paper or printing paper, and at the same time an image is formed on the label paper or printing paper. As a result, the information written in the RF tag and the image information that can be acquired visually are linked, so the convenience of article management is greatly improved. In order to perform such operations, an image forming apparatus with a wireless communication function that can perform both communication with an RF tag and image formation is generally used.

  By the way, in such an image forming apparatus with a wireless communication function, since the wireless communication apparatus and its communication antenna are housed in the housing of the apparatus, the metal parts or the like constituting the image forming apparatus reflect radio waves. Therefore, there is a problem that communication failure is likely to occur. If there are no obstacles in the reach of the radio wave, the radio wave that reaches the RF tag from the antenna is only a direct wave, but in a general environment, a reflected wave is always generated by a conductor such as a metal member. Multipath in which radio waves passing through the route reach the RF tag becomes a problem. That is, multipath fading occurs in which reflected waves and direct waves with different phases overlap each other, thereby generating a dead area (Null spot) in which radio waves are weakened in the communication area. In particular, when a communication antenna is arranged in the image forming apparatus, there are many metal parts in the vicinity, and thus a communication failure problem due to multipath is very likely to occur.

  In this case, securing communication performance with the RF tag under a specific condition is likely to be achieved by verifying and determining the positional relationship between the RF tag and the antenna. Since this is a radio wave reflecting member and the influence from the Null spot is different, suitable conditions vary depending on the type of RF tag. Therefore, it is virtually impossible to guarantee communication performance for an arbitrary RF tag. Communication with the RF tag in the Null spot is likely not to succeed even if the number of retries is repeated under the same conditions. Therefore, the Null spot can be eliminated by changing one of the parameters generally involved. After that, measures are taken to retry communication.

  For example, methods such as changing a communication frequency, moving an antenna, and moving a radio wave reflecting member are known (Patent Document 1).

JP 2008-117302 A

  However, the above-described conventional measures require the development of a wireless communication device that can communicate by switching a plurality of frequencies, or it involves the addition of a dedicated antenna moving mechanism or the addition of a dedicated radio wave reflection component. There is a problem that it takes development man-hours and the cost becomes high.

  The present invention has been made in view of the above problems, and an object thereof is to improve the success rate of communication with an arbitrary RF tag with a simple configuration.

In order to solve the above problems, an image forming apparatus according to the present invention provides:
A carriage that reciprocates in the main scanning direction, on which image forming means for forming an image on a recording medium is mounted;
Means for communicating with an RF tag provided on the recording medium;
A communication antenna provided in a range where an output radio wave reaches the carriage;
And a means for performing control to retry communication with the RF tag by adjusting the reflection state of radio waves by moving the carriage when communication with the RF tag fails.

  Here, when continuously forming images on a plurality of recording media, the position of the carriage that has successfully communicated with the RF tag of the first recording medium is stored, and the second and subsequent recordings The carriage can be moved to the stored position to communicate with the RF tag.

  Further, the type of the recording medium provided with the RF tag and the position information of the carriage when the communication with the RF tag is successful are stored and designated when the communication with the RF tag is performed. The carriage can be moved to the stored position based on the detected type of the recording medium.

  In addition, the radio wave reflection unit may be configured to be movable, and when communication with the RF tag fails, the radio wave reflection unit may be moved to perform control to retry communication with the RF tag.

  In addition, the radio wave absorber may be arranged so as to be movable, and when communication with the RF tag fails, the radio wave absorber may be moved to perform control to retry communication with the RF tag.

  According to the image forming apparatus of the present invention, when the communication with the RF tag fails, the carriage is moved to adjust the reflection state of the radio wave, and the control for retrying the communication with the RF tag is performed. The success rate of communication with the RF tag can be improved with a simple configuration.

1 is an explanatory plan view showing a schematic configuration of an ink jet recording apparatus as an image forming apparatus according to a first embodiment of the present invention. It is principal part side explanatory drawing of the apparatus. It is a functional block diagram which shows the outline | summary of the control part of the apparatus. It is a flowchart with which it uses for description of communication retry control. It is an explanatory plan view for explaining the control. It is an explanatory plan view for explaining the control. It is a plane explanatory view explaining an example of a 2nd embodiment of the present invention. It is a plane explanatory view explaining other examples of the embodiment. It is a plane explanatory view explaining a 3rd embodiment of the present invention. It is a flowchart explaining 4th Embodiment of this invention. It is a flowchart explaining 5th Embodiment of this invention. It is explanatory drawing with which description of the embodiment is provided.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. First, an outline of an ink jet recording apparatus as an image forming apparatus according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 1 is an explanatory plan view showing a schematic configuration of the ink jet recording apparatus, and FIG. 2 is an explanatory side view of a main part of the apparatus.

  In this ink jet recording apparatus, a carriage 3 is slidably held by a main guide rod 1 horizontally mounted on left and right side plates (not shown) and a sub guide member (not shown), and between a driving pulley 6 and a driven pulley 7 by a main scanning motor 5. The moving scanning is performed in the main scanning direction via the timing belt 8 passed to.

  The carriage 3 has recording heads 4a and 4b as image forming means including liquid ejection heads for ejecting ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (K). (When not distinguished, it is referred to as “recording head 4”.) A nozzle row composed of a plurality of nozzles is arranged in the sub-scanning direction orthogonal to the main scanning direction, and is mounted with the ink droplet ejection direction facing downward.

  Each of the recording heads 4 has two nozzle rows 4. One nozzle row of the recording head 4 a has yellow (Y) droplets, the other nozzle row has magenta (M) droplets, and the recording head 4 b. One nozzle row is assigned to discharge cyan (C) droplets, and the other nozzle row is assigned to discharge black (K) droplets.

  The liquid discharge head constituting the recording head 4 includes a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change caused by liquid film boiling using an electrothermal transducer such as a heating resistor, and a metal phase change caused by a temperature change. A shape memory alloy actuator using an electrostatic force, an electrostatic actuator using an electrostatic force, and the like provided as pressure generating means for generating a pressure for discharging a droplet can be used.

  On the other hand, in order to transport the paper 10, transport rollers 11 and 12 are provided as transport means for transporting the paper 10. The transport rollers 11 and 12 are rotationally driven by a sub-scanning motor 16 via a timing belt 17 and a timing pulley 18.

  Further, a maintenance / recovery mechanism 21 that performs maintenance / recovery of the recording head 4 is disposed on one side of the carriage 3 in the main scanning direction. The maintenance / recovery mechanism 21 includes, for example, a cap member 22 for capping the nozzle surface (surface on which the nozzles are formed) of the recording head 4, a wiper member 23 for wiping the nozzle surface, and the like.

  Further, an encoder scale 31 is disposed along the main scanning direction of the carriage 3, and the carriage 3 is provided with an encoder sensor 32 that reads the encoder scale 31, thereby detecting the position of the carriage 3. Is configured. Based on the detection signal from the encoder sensor 32, the position of the carriage 3 is detected when the carriage 3 is at a position facing the maintenance / recovery mechanism 21 as a home position (home position).

  In addition, an encoder wheel 33 is provided on the shaft of the transport roller 11, and an encoder sensor 34 that reads the encoder wheel 33 is provided, thereby constituting a rotary encoder (sub-scanning encoder) that detects a paper feed amount.

  In the image forming apparatus configured as described above, the sheet 10 is conveyed in the sub-scanning direction by the rotation of the conveying roller 11 from a sheet feeding tray (not shown). Therefore, by driving the recording head 4 according to the image signal while moving the carriage 3 in the main scanning direction, ink droplets are ejected onto the stopped paper to record one line, and the paper is conveyed by a predetermined amount. After that, the next line is recorded. Upon receiving a recording end signal or a signal indicating that the trailing edge of the sheet has reached the recording area, the recording operation is terminated and the sheet is discharged to a discharge tray (not shown).

Next, a configuration related to reading of the RF tag in the image forming apparatus will be described.
An RFID communication control device 41 that communicates with the RD tag 40 provided on the paper 10 is provided, and a communication antenna 43 connected from the RFID communication control device 41 via a cable 42 is disposed on the conveyance path of the paper 10. . The paper 10 provided with the RF tag 40 is transported in the sub-scanning direction by the transport means described above, and stopped at a predetermined position near the communication antenna 43. Thereby, the RF tag 40 can receive the radio wave from the communication antenna 43, the RFID communication control device 41 communicates with the RF tag 40, and the information stored in the RF tag 40 is read.

  After the reading of the RF tag 40 is completed, image formation on the paper 10 is started as described above.

Next, an outline of the control unit of the image forming apparatus will be described with reference to the functional block diagram of FIG.
The control unit 100 controls the entire apparatus. The CPU 101, the ROM 102, the RAM 103, the image output control unit 104, the main scanning control unit 105, the sub scanning control unit 106, the host I / F 107, the encoder analysis unit 108, and the I / O 109. Etc.

  Firmware for performing hardware control of this apparatus and drive waveform data for generating a common drive signal to be sent to the head driver 111 for driving the recording head 4 are stored in the ROM 102. The RAM 102 is used as various buffers and work memories and stores various data. The image output control unit 104 includes a drive signal generation circuit that generates a common drive signal to the recording head 4, and sends the common drive signal together with the image data and the control signal to the head driver 111 mounted on the carriage 3 side. The droplets are ejected from the recording head 4 at the droplet ejection timing obtained based on the movement amount of the carriage 3 obtained from the encoder analysis unit 108.

  The main scanning control unit 105 controls the movement and stop position of the carriage 3 by controlling the driving of the main scanning motor 5 based on the movement amount analyzed and calculated by the encoder analysis unit 108. The sub-scanning control unit 106 controls the feeding of the paper 10 by driving and controlling the sub-scanning motor 16 based on the movement amount of the paper 10 analyzed and calculated by the encoder analysis unit 108 and rotating the transport roller 11.

  The encoder analysis unit 108 receives and analyzes detection signals from the encoder sensor 32 constituting the main scanning encoder 112 and the encoder sensor 34 constituting the sub-scanning encoder 113. The encoder 108 includes a direction detection unit 121 that detects a direction and a counter 122 that counts a detection signal.

  The control unit 100 receives a print job (image data) transferred from the printer driver 201 of the host (information processing apparatus such as a PC) 200 via the host I / F 107 and stores the received bitmap image data. To do. Here, the printer driver 201 on the host 200 side develops the image data into bitmap data and transfers it to the recording apparatus. However, when performing bitmap development on the recording apparatus side, the I / F 107 is used. The transfer data stored in the reception buffer included in is read and analyzed, the analysis result (intermediate code data) is stored in a predetermined area of the RAM 103, and the font data stored in the ROM 102 is stored from the stored analysis result. Dot pattern data for outputting an image is generated and stored again in a different predetermined area of the RAM 103.

  Then, the main scanning motor 6 and the sub-scanning motor 16 are driven and controlled, the carriage 3 is moved to the target position at the target speed, and the paper 10 is fed. Then, the actuator unit 114 including various sensors and motors is cooperatively controlled through the I / O 109, and printing is performed by transferring image data from the image output control unit 104 to the recording head 4.

  Also, the RFID driver 202 of the host 200 issues various commands for communicating with the RF tag 40 to the RFID communication control unit 115 (included in the RFID communication control device 41) on the image forming apparatus side, and the RFID Make communication. On the host 200 side, the upper RFID printing application 203 that performs integrated control of the printer driver 201 and the RFID driver 202 issues instructions to the drivers 201 and 202 as appropriate, thereby reading and writing RFID data to and from the RF tagged paper 10. Perform image formation.

  In this example, the communication antenna 43 is arranged on the upstream side of the carriage 3 and the operation proceeds to the printing operation after the RFID communication is completed. However, the installation position of the communication antenna 43 and the execution of printing and RFID communication are described. The sequence is not limited to this.

Next, RFID communication in this image forming apparatus will be described.
When performing RFID communication, a radio communication radio wave is output from the communication antenna 3 by a signal from the RFID communication control device 41. The radio wave receives both a direct wave that reaches the RF tag 40 directly and a reflected wave that is reflected by the metal frame constituting the image forming apparatus, the transport roller 11, the motors 5 and 16, and the like.

  Therefore, a Null spot due to multipath fading as described above occurs, and if this occurs at the position of the RF tag 40, a communication failure will be caused. In a communication failure due to the occurrence of a null spot, a signal cannot be transmitted due to a decrease in radio field intensity, or erroneous recognition of data is caused. As a result, if normal communication is completed, a communication completion command should be sent from the RFID communication control unit 115 to the RFID driver 202. However, this is not issued and a time-out occurs, or the RFID communication control unit 115 generates an error command. Is issued, the RFID driver 202 recognizes the failure.

  In the image forming apparatus as described above, it is impossible to completely remove components that reflect radio waves, and even if the number of components that reflect radio waves is reduced, it is not possible to remove completely, so the generation pattern of Null spots is changed. However, it is not known whether the radio wave environment at the position of the RF tag 40 is improved or deteriorated. For this reason, there is a possibility of improving even if the number of members that reflect radio waves is increased or the direction of emitting a strong reflected wave closer to the antenna 43 is changed, and communication is performed under many conditions by changing parameters little by little. Retrying increases the possibility of finding a communicable condition according to the parameter width and the number of retries.

  In this case, it is effective to change the communication frequency for fluctuations in the position where the Null spot is generated, but it is necessary to mount a frequency switching function in the RFID communication control device 41 in advance, which is disadvantageous in terms of cost. Because the frequency that can be used in the regulation is defined, the degree of freedom is limited.

The retry control by this image forming apparatus will be described with reference to FIGS.
Referring to FIG. 4, when communicating with the RF tag 40, it is determined whether the RFID communication is successful by performing RFID communication with the carriage 3 in the n position, and when the communication is not successful (unsuccessful). ), The carriage 3 is moved from the n position to the next (n + 1) position, and communication with the RF tag 40 is performed again (retry). When RFID communication is successful, the process shifts to print control.

  Here, when the carriage 3 is moved, the position (n + 1) may be one or a plurality of different positions. In the case of a plurality of different positions, if it is unsuccessful at the (n + 1) position, the (n + 1) position is set as the n position and moved to the next (n + 1) position.

  More specifically, referring to FIG. 5, for example, RFID communication is performed with the carriage 3 as a home position. At this time, the carriage 3 is mounted with a radio wave reflecting member such as a PCB including a copper foil layer, a liquid discharge head (recording head 4) made of metal or semiconductor, and other harnesses. Therefore, the radio wave output from the communication antenna 43 is reflected by these members in the carriage 3 and returns a reflected wave (arrow 200) to the RF tag 40. The RF tag 40 receives a superposition of this reflected wave, a direct wave from the communication antenna 43, and a large number of reflected waves reflected by other members.

  Therefore, for example, RFID communication is performed by setting the home position of the carriage 3 to the n position (predetermined position). At this time, when a null spot is generated at the coordinates of the RF tag 40 and a communication failure is caused (in the case of unsuccessful communication). ), The carriage 3 is moved from the home position to the sheet left end position which is the next (n + 1) position (a position different from the predetermined position) as shown in FIG. Thereby, the reflected wave by the carriage 3 or the like can be adjusted, and the state of the multipath reaching the RF tag 40 is changed, so that the Null spot may disappear or move, and the communication failure may be eliminated. If the communication failure is still not resolved, the communication failure can be similarly eliminated by moving the carriage 3 from, for example, the left end position of the sheet to the center position of the sheet and retrying the RFID communication in the same manner. there is a possibility.

  The position where the carriage is moved for retrying is not limited to the left edge of the sheet or the center of the sheet, and may be any position. Further, as described above, the carriage may be moved sequentially to a plurality of different positions, for example, in steps of 1 cm. good.

  As described above, when the RFID communication performed with the carriage 3 in the predetermined position is not established, the carriage 3 is moved to a position different from the predetermined position to adjust the reflection state of the radio wave, and to the RF tag. By performing control to retry communication, it is possible to find a condition for successful communication with the RF tag 40, and to improve the success rate of communication with the RF tag with a simple configuration.

Next, a different example of the second embodiment of the present invention will be described with reference to FIGS. 7 and 8 are explanatory plan views of the main part of the embodiment.
First, in the example shown in FIG. 7, a radio wave reflection member 45 made of a good conductor is provided on the radio wave irradiation surface of the carriage 3. Thereby, the reflected wave reflected by the carriage 3 can be made stronger, and the contribution of the reflected wave from the carriage 3 received by the RF tag 40 can be increased. As a result, it is possible to increase the degree of influence when the position of the carriage 3 is changed, and to search for suitable conditions with a wider width.

  Next, in the example shown in FIG. 8, the support shaft 47 attached with the radio wave reflection member 46 eccentrically and the rotation shaft 11 a of the paper conveyance roller 11 are connected by a pulley 48, and the radio wave reflection member 46 is rotated by the rotation of the conveyance roller 11. Is trying to rotate. As described above, by moving the radio wave reflection member 46 in connection with the movable part of the apparatus, it is possible to obtain the same effect as that of FIG. 7 without adding a new actuator and actuator control unit.

  However, in the configuration shown in FIG. 8, the movement of the radio wave reflection member 46 is accompanied by the rotation of the transport roller 11, so the RF tag 40 also moves. When it is desired to move only the radio wave reflection member 46, the driving of the transport roller of the transport means can be temporarily disconnected using a gear or a clutch.

Next, a third embodiment of the present invention will be described with reference to FIG. FIG. 9 is an explanatory plan view of a main part of the embodiment.
Here, instead of the radio wave reflection member 45 of the second embodiment, a radio wave absorber 49 is provided in the carriage 3. Thereby, the same effect as the said 2nd Embodiment can be acquired. In addition, by installing a radio wave absorber at a site where radio waves are reflected by a metal part or the like, the reflected waves can be reduced and the multipath state received by the RF tag can also be changed.

Next, a fourth embodiment of the present invention will be described with reference to the flowchart of FIG.
Here, when performing continuous printing using a plurality of sheets of the same RF tag 40 fixed at the same position, such as printing of a plurality of pages or a plurality of copies (referred to as printing of a plurality of sheets), the communication of the RF tag 40 Suitable conditions are generally the same for any page (paper) as long as the radio wave reflection conditions do not change. Therefore, the position of the carriage 3 (referred to as “preferred position”) at which the RFID communication found when the first sheet is printed is stored, and this is reproduced for the second and subsequent sheets. The time for searching for a suitable position can be omitted, and RFID communication can be completed in a short time.

  That is, referring to FIG. 10, when printing a plurality of sheets, the preferred position (position of the carriage 3 when communication with the RF tag 40 is successful) S stored in the RAM 102 or the like is read and the carriage Position information is set, the carriage 3 is moved to a suitable position S, and RFID communication is started. The preferred position S stores an initial value (for example, a carriage home position) in the first printing.

  Then, it is determined whether the RFID communication is successful. If the communication is not successful, the communication retry is performed by changing the position of the carriage 3 as described above. That is, as described above, the carriage 3 is moved from the n position to the (n + 1) position to perform communication retry, and at this time, an update process for setting the changed carriage position to the suitable position S is also performed.

  Here, when the communication is successful, it is determined whether or not the suitable position S has been searched (the carriage position has been changed from the stored preferred position S), and when the preferred position S has been searched, After storing the updated preferred position S, printing is performed. When the preferred position S is not searched, printing is performed as it is.

  Thereafter, it is determined whether or not all printing has been completed. If all printing has not been completed, the process returns to the reading process of the stored preferred position S to perform RFID communication and printing for the next sheet.

  As a result, the preferred position S where the RFID communication is successful is searched for the first sheet, the searched preferred position S is stored, and the carriage 3 is moved to the preferred position S for the second and subsequent sheets. It moves and performs RFID communication. In this case, since the second and subsequent sheets have the same reflected wave conditions as the first sheet, RFID communication succeeds by performing RFID communication at the preferred position S obtained for the first sheet. The probability is high (the probability that communication is unsuccessful is low), and the time for searching for the preferred position S of the carriage 3 for communication success is substantially reduced or shortened. There is little decrease and the printing speed can be improved.

Next, a fifth embodiment of the present invention will be described with reference to a flowchart shown in FIG. 11 and an explanatory diagram shown in FIG.
Here, when performing RFID communication and printing, the user inputs or selects the name of the RF-tagged paper to be used, and stores the conditions (preferred position of the carriage) for successful RFID communication at this time. When the same type of paper is used, the preferred position search time can be omitted by reading the preferred position of the carriage when the paper is used and performing RFID communication.

  That is, in the rewritable nonvolatile memory, as shown in FIG. 12, the relationship between the paper type and the carriage position (this is referred to as “preferred position T”) when the RFID communication for the paper is successful is tabulated. (This is referred to as a “paper type table”) and stored.

  Therefore, as shown in FIG. 11, in response to designation of the paper type by the user, it is determined whether or not a suitable position T corresponding to the paper type is stored in the paper type table. Is stored, the position information is set, the carriage 3 is moved to the position T that has been read, and RFID communication is started. Further, when the preferred position T is not stored in the paper type table, RFID communication is started with the carriage 3 as it is at the initial position (for example, the above-described home position).

  Then, it is determined whether or not the communication is successful, and whether or not the RFID communication is successful is determined. If the communication is not successful, the communication retry is performed by changing the position of the carriage 3 as described above. That is, as described above, the carriage 3 is moved from the n position to the (n + 1) position to perform communication retry.

  Here, when the communication is successful, it is determined whether or not a search for the preferred position T has been performed (the carriage position has been changed from the stored preferred position T), and when the preferred position T is searched, Printing is performed after performing a table update process in which the carriage position at that time is stored as the preferred position T of the paper type, and printing is performed as it is when searching for the preferred position T is not performed.

  As a result, for the same paper type, RFID communication can be performed from the first access at the preferred position T. Therefore, it is unlikely that a retry is required, and communication can be completed in a short time.

  Also, when there is no suitable position information corresponding to the paper type table, or when the corresponding suitable position information is stored but a retry occurs, information on the preferred position determined by searching for a new suitable position is displayed. Record in the paper type table. As a result, in the job using the same sheet, the added / updated preferred position information can be used from the next time.

  In this way, by learning and storing the preferred position, for the paper having the preferred position information in advance, communication is performed at the preferred position from the first RFID communication, and communication is completed in the shortest communication time. Thus, even for a sheet that does not have information on a suitable position, communication can be completed in the shortest communication time from the learning result on and after the next time.

  In the fourth and fifth embodiments, the preferred position (preferred condition) is the carriage position. However, it is not limited to the carriage position, and other conditions (for example, the radio wave reflecting member and the radio wave absorbing member are movable separately from the carriage). The position of the radio wave reflecting member or the radio wave absorbing member in the case of being provided in the unit can also be stored.

3 Carriage 4 Recording head 10 Paper (recording medium)
40 RF Tag 41 RFID Communication Control Device 43 Communication Antenna 115 RFID Communication Control Unit

Claims (5)

A carriage that reciprocates in the main scanning direction, on which image forming means for forming an image on a recording medium is mounted;
Means for communicating with an RF tag provided on the recording medium;
A communication antenna provided in a range where an output radio wave reaches the carriage;
And a means for performing control to retry communication with the RF tag by adjusting the reflection state of radio waves by moving the carriage when communication with the RF tag fails. Forming equipment.   When images are continuously formed on a plurality of recording media, the position of the carriage that has successfully communicated with the RF tag of the first recording medium is stored, and the second and subsequent recording positions are stored. The image forming apparatus according to claim 1, wherein the carriage is moved to perform communication with the RF tag.   The type of the recording medium provided with the RF tag and the position information of the carriage when the communication with the RF tag is successful are stored and designated or detected when the communication with the RF tag is performed. The image forming apparatus according to claim 1, wherein the carriage is moved to a stored position based on a type of the recording medium.   A radio wave reflection unit arranged to be movable, and when the communication with the RF tag fails, the radio wave reflection unit is moved to perform control to retry communication with the RF tag. Item 4. The image forming apparatus according to any one of Items 1 to 3.   A radio wave absorber disposed so as to be movable, and when communication with the RF tag fails, the radio wave absorber is moved to perform control to retry communication with the RF tag. Item 4. The image forming apparatus according to any one of Items 1 to 3.

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