Image forming apparatus

Abstract

To provide an image forming apparatus that allows a user to easily discriminate, by visual inspection, a print medium comprising a wireless tag that cannot be normally processed.SOLUTION: According to an embodiment, an image forming apparatus has a communication device, a transfer unit, and a processor. The communication device communicates with a wireless tag. The transfer unit transfers a developer image formed with developer to a medium comprising the wireless tag communicating with the communication device. When the communication with the wireless tag is normally executed by the communication device, the processor controls the operation of the transfer unit with a first control value, and when the communication with the wireless tag is not normally completed by the communication device, controls the operation of the transfer unit with a second control value different from the first control value.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] Embodiments of the present invention relate to an image forming apparatus.

Background Art

[0002] Conventionally, there is an image forming apparatus having a tag communication device that communicates with an RFID tag, which is a wireless communicator (wireless tag) provided on a sheet for printing an image. The image forming apparatus having the tag communication device can perform processing such as writing data or reading data (hereinafter, also referred to as tag processing) on the RFID tag of the sheet. It is desirable that the image forming apparatus can distinguish a sheet on which tag processing such as writing or reading to the RFID tag has failed from other sheets.

[0003] For example, conventionally, there is an image forming apparatus that discharges a sheet on which tag processing has failed to a different discharge destination from a sheet on which tag processing has succeeded. However, there is a problem that a sheet provided with an RFID tag on which tag processing has failed cannot be visually distinguished from a sheet on which tag processing has succeeded even if the discharge destination is changed. Also, there is an image forming apparatus that prints an image indicating a write failure when writing data to the RFID tag fails. However, the image forming apparatus has a problem that the operation of printing an image different from the printing image on a sheet on which writing to the RFID tag has failed during printing is complicated and time-consuming.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The problem to be solved by the present invention is to provide an image forming apparatus that can easily visually discriminate a printing medium provided with a wireless tag that cannot be processed normally. [Means for solving the problem]

[0006] According to one embodiment, the image forming apparatus includes a communication device, a transfer unit, and a processor. The communication device communicates with a wireless tag. The transfer unit transfers a developer image formed with a developer onto a medium that has a wireless tag communicating with the communication device. The processor receives the wireless tag from the communication device. The data writing process for this will be completed within a specified time. If executed successfully, the operation of the transfer device is controlled by the first control value, and wireless tagging is performed by the communication device. The data writing process for this will be completed within a specified time. If the process does not complete successfully, the operation of the transfer device is controlled by a second control value that is different from the first control value. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 shows an example of the configuration of an image forming apparatus according to an embodiment. [Figure 2] Figure 2 is a block diagram showing an example of the configuration of the control system in an image forming apparatus according to an embodiment. [Figure 3] Figure 3 shows an example of the configuration of an image forming system including an image forming apparatus according to an embodiment. [Figure 4] Figure 4 shows an example of the transition of the secondary transfer bias in an image forming apparatus according to the embodiment. [Figure 5] Figure 5 shows a first example of the transition of the secondary transfer bias in the image forming apparatus according to the embodiment. [Figure 6] Figure 6 shows an example of the transition of the secondary transfer bias in an image forming apparatus according to the embodiment. [Figure 7] Figure 7 is a flowchart illustrating an example of the operation of a printing process, including tagging, in an image forming apparatus according to an embodiment. [Modes for carrying out the invention]

[0008] This embodiment will be described below with reference to the drawings. First, the configuration of the image forming apparatus 1 according to this embodiment will be described. Figure 1 shows an example configuration of a digital multifunction device (MFP, Multi-Functional Peripheral) equipped with an electrophotographic printer, which is an example of an image forming apparatus 1 according to the embodiment. The image forming apparatus 1 according to this embodiment includes a printer that forms an image on a printing medium P and a tag communication device that communicates with an RFID tag, which is a wireless tag (wireless communication device) provided on the printing medium P. For example, the image forming apparatus 1 is placed in a workplace.

[0009] A wireless tag is a small wireless communication device that includes a processor, internal memory, wireless communication circuitry, and antenna. An example of a wireless tag is an RFID (Radio Frequency Identification) tag. A wireless tag communicates with a tag communication device, which is a wireless communication device. The wireless tag performs processing in response to commands supplied by the tag communication device and responds to the tag communication device with the results of the processing. For example, if a wireless tag receives a read command, it reads the data stored in its internal memory and responds with the read data. Similarly, if a wireless tag receives a write command, it writes the requested data to its internal memory and outputs a response indicating the write result.

[0010] The printer of the image forming apparatus 1 according to this embodiment prints an image on a printing medium P equipped with a wireless tag. The printing medium P is, for example, a sheet. The sheet as the printing medium P may have a wireless tag embedded in it, or it may have a wireless tag attached to it. Hereinafter, the explanation will assume that the printing medium P is a sheet equipped with an RFID tag as an example of a wireless tag.

[0011] In the configuration example shown in Figure 1, the image forming apparatus 1 has a printer that forms an image on a printing medium P by an electrophotographic process. However, the image forming method of the image forming apparatus 1 according to this embodiment is not limited to the electrophotographic method. The printer of the image forming apparatus 1 in the configuration example shown in Figure 1 forms an image to be developed on the printing medium P using toner (developer). The toner may be a single-color toner or a multi-color toner. The toner may also be a toner that can be erased. Figure 1 shows a configuration example of the image forming apparatus 1 that performs image forming processing using four color toners: yellow, magenta, cyan, and black.

[0012] In the configuration example shown in Figure 1, the image forming apparatus 1 comprises a housing 11, a communication interface 12, a controller 13, multiple paper trays 14, an output tray 15, a transport mechanism 16, an image forming mechanism 17, a fuser 18, a scanner 20, and a control panel 21.

[0013] The housing 11 is the main body of the image forming apparatus 1. The housing 11 houses, for example, a communication interface 12, a controller 13, multiple paper trays 14, a transport mechanism 16, an image forming mechanism 17, and a fuser 18. A portion of the top surface of the housing 11 serves as the paper output tray 15.

[0014] The communication interface 12 is an interface for communicating with other devices connected via a network. The communication interface 12 is used for communication with external devices. External devices include user terminals that instruct print jobs, or servers that act as management devices for managing information on RFID tags on the print medium P. The communication interface 12 is composed of, for example, a LAN connector. The communication interface 12 may also perform wireless communication with other devices in accordance with standards such as Bluetooth® or Wi-Fi®.

[0015] The controller 13 controls each part of the image forming apparatus 1 and executes data processing and the like. For example, the controller 13 is a computer including a processor, a memory, and various interfaces. The controller 13 controls each part and performs data processing by the processor executing the programs stored in the memory. The controller 13 is connected to each part within the housing 11 through various internal interfaces. For example, the controller 13 is connected to the communication interface 12, the paper discharge tray 15, the conveyance mechanism 16, the image forming mechanism 17, the fixing device 18, and the scanner 20 and the like.

[0016] The controller 13 acquires a print job including image data and the like received from an external device via the communication interface 12. The image data included in the print job is data indicating an image to be formed on the print medium P. The image data may be data for forming an image on one print medium P or may be data for forming images on a plurality of print media P.

[0017] Also, the print job may include information indicating the processing content for the RFID tag provided on the print medium P. The processing content for the RFID tag may be an instruction to write data to the RFID tag or may be an instruction to read data from the RFID tag. Further, the print job may include information indicating the paper discharge position (paper discharge tray, paper discharge direction, etc.) for discharging the print medium P on which an image has been formed. Also, the print job may include information indicating print conditions such as information indicating whether it is color printing or monochrome printing.

[0018] The controller 13 includes an engine controller that controls the operations of the conveyance mechanism 16, the image forming mechanism 17, and the fuser 18. For example, the controller 13 controls the conveyance of the print medium P by the conveyance mechanism 16. The controller 13 controls the formation of the developer image by the image forming mechanism 17 and the transfer of the developer image to the print medium P. The controller 13 controls the fixing of the developer image to the print medium P by the fuser 18. By controlling the operations of the conveyance mechanism 16, the image forming mechanism 17, and the fuser 18, the controller 13 forms an image of the image data included in the print job on the print medium P.

[0019] Note that the image forming apparatus 1 may be configured to include an engine controller separately from the controller 13. For example, the image forming apparatus 1 may be provided with an engine controller that controls at least one of the conveyance mechanism 16, the image forming mechanism 17, the fuser 18, etc., separately from the controller 13. The engine controller provided separately from the controller 13 may obtain information necessary for control from the controller 13.

[0020] The plurality of paper trays 14 are cassettes that each accommodate the print medium P. The paper tray 14 is configured to be able to replenish the print medium P provided with an RFID tag. For example, the paper tray 14 is configured to be pullable out from the housing 11. After the print medium P provided with an RFID tag is replenished in the pulled-out state, the paper tray 14 is set again into the housing 11.

[0021] The conveyance mechanism 16 is a mechanism that conveys the print medium P within the image forming apparatus 1. As shown in FIG. 1, the conveyance mechanism 16 includes a plurality of conveyance paths. The conveyance mechanism 16 includes a paper feed conveyance path 31 and a paper discharge conveyance path 32.

[0022] The paper feed conveyance path 31 and the paper discharge conveyance path 32 are constituted by a plurality of rollers and a plurality of guides, etc. The plurality of rollers rotate by the power transmitted from the drive mechanism to convey the print medium P. The plurality of guides control the conveyance direction of the print medium P conveyed by the rollers.

[0023] The paper feed transport path 31 takes in the printing medium P from the paper tray 14 and supplies the taken printing medium P to the image forming mechanism 17. The paper feed transport path 31 is equipped with multiple pickup rollers 33, each corresponding to one of the paper trays 14. Each pickup roller 33 feeds one printing medium P from the paper tray 14 into the paper feed transport path 31.

[0024] The paper feed transport path 31 supplies the printing medium P to the transfer position of the image (toner image) generated by the image forming mechanism 17 using toner (developer). The registration roller 36 is located before the transfer position in the paper feed transport path 31. The registration roller 36 feeds the printing medium P fed from the paper tray 14 to the transfer position according to the image transfer timing at the transfer position. For example, the registration roller 36 temporarily stops the printing medium P fed from the paper tray 14. The registration roller 36 then feeds the printing medium P to the transfer position in response to instructions from the system controller 13.

[0025] The paper discharge transport path 32 is a transport path that discharges the printing medium P, on which an image has been formed by the image forming mechanism 17, from the housing 11. The paper discharge transport path 32 discharges the printing medium P into the paper discharge tray 15. The paper discharge tray 15 is a tray that receives the printing medium P discharged from the image forming apparatus 1. Furthermore, if the image forming apparatus 1 has multiple paper discharge positions, the paper discharge transport path 32 operates to discharge the printing medium P into the paper discharge position specified by the system controller 13.

[0026] The image forming mechanism 17 has a configuration for forming an image on the printing medium P. Details of the image forming mechanism 17 will be described later. The fuser 18 has a heat roller 34 and a pressure roller 35. The fuser 18 heats the printing medium P being transported along the paper discharge path 32 to a predetermined temperature using the heat roller 34. The fuser 18 further pressurizes the printing medium P, which is being heated by the heat roller 34, with the pressure roller 35. By heating and pressurizing the printing medium P, the fuser 18 fixes the image (developer image) on the printing medium P to the printing medium P.

[0027] The tag communication device 19 communicates with the RFID tag, which is a wireless communication device (wireless tag) provided on the printing medium P. The tag communication device 19 is positioned to communicate with the RFID tag on the printing medium P located in front of the registration roller 36. The tag communication device 19 supplies commands to the RFID tag via wireless communication. The tag communication device 19 receives a response from the RFID tag. The RFID tag executes processing according to the command from the tag communication device 19 and transmits (responds to) the result of the command execution to the tag communication device 19.

[0028] The tag communication device 19 reads data from or writes data to an RFID tag in response to instructions from the system controller 13. When the system controller 13 instructs the tag communication device 19 to read data from an RFID tag, it executes the process of reading data from the RFID tag. When the system controller 13 instructs the tag communication device 19 to write data to an RFID tag, it executes the process of writing data to the RFID tag.

[0029] The scanner 20 is a device that reads a document and converts it into image data. The scanner 20 is installed on top of the housing 11. The scanner 20 reads the image of the document placed on the document glass located on top of the housing 11. The scanner 20 also has an automatic document feeder (ADF). The scanner 20 also has the function of reading the image of the document being transported by the automatic document feeder (ADF).

[0030] The control panel 21 includes a touch panel 22 and a keyboard 23, etc. The touch panel 22 is, for example, a stacked display such as a liquid crystal display or an organic EL display and a touch sensor that detects touch input. The display equipped with the touch panel 22 is the display device of the image forming apparatus 1.

[0031] The keyboard 23 is equipped with various keys for the user to operate the image forming apparatus 1. For example, the keyboard 23 includes a numeric keypad, a power key, a paper feed key, function keys, etc. Each key may also be called a button. The touch panel 22 and the keyboard 23 are input devices for the image forming apparatus 1.

[0032] Next, the image formation mechanism 17 will be described. As shown in Figure 1, the image forming mechanism 17 comprises a plurality of image forming stations 41 and a transfer mechanism 42. Each image forming station 41 forms a toner image. Each image forming station 41 is provided for each type of toner. In the example shown in Figure 1, each image forming station 41 corresponds to a color toner such as yellow, magenta, cyan, and black, from left to right. Each image forming station 41 is equipped with a toner cartridge 2 having a color toner of the corresponding color. Figure 1 illustrates an image forming apparatus 1 equipped with four image forming stations 41, each corresponding to one of four color toners: yellow, magenta, cyan, and black.

[0033] Next, we will describe each image forming station 41. Each image forming station 41 is equipped with a photoreceptor drum (photoreceptor) 71, a cleaner 72, a charger 73, an exposure unit 74, a developer unit 75, and a primary transfer roller (transfer unit). The photoreceptor drum 71 comprises a cylindrical drum and a photosensitive layer formed on the outer surface of the drum. The photoreceptor drum 71 is the photoreceptor. The outer surface of the photoreceptor drum 71 is the image carrier. The photoreceptor drum 71 rotates at a constant speed by power transmitted from the drive mechanism. The cleaner 72 has a blade that contacts the surface of the photoreceptor drum 71. The cleaner 72 uses the blade to remove any toner remaining on the surface of the photoreceptor drum 71.

[0034] The charger 73 uniformly charges the surface of the photoreceptor drum 71. The charger 73 is also called a charge charger. The charger 73 charges the photoreceptor drum 71 to a uniform negative potential (surface potential) by applying a grid bias voltage (charging potential) output from the grid electrode to the photoreceptor drum 71.

[0035] The exposure unit 74 is equipped with multiple light-emitting elements. These light-emitting elements are, for example, laser diodes (LDs), light-emitting diodes (LEDs), or organic light-emitting diodes (OLEDs). The multiple light-emitting elements are arranged in the main scanning direction, which is parallel to the rotation axis of the photoreceptor drum 71. Each light-emitting element is configured to irradiate light onto a single point on the photoreceptor drum 71.

[0036] The exposure unit 74 forms a single line of electrostatic latent image on the photoreceptor drum 71 by irradiating the surface of the charged photoreceptor drum 71 with light from multiple light-emitting elements arranged in the main scanning direction. Furthermore, the exposure unit 74 forms multiple lines of electrostatic latent images by continuously irradiating the rotating photoreceptor drum 71 with light.

[0037] The developer unit 75 is a device that deposits toner onto the photoreceptor drum 71. The developer unit 75 contains a developer containing toner and carrier. The developer unit 75 agitates the toner and carrier supplied from the toner cartridge 2 using an agitation mechanism. The developer unit 75 supplies toner to the photoreceptor drum 71 from the developing roller to which the developer containing the agitated toner and carrier is attached. The developer unit 75 develops the electrostatic latent image on the photoreceptor drum 71 with toner by supplying toner to the photoreceptor drum 71. The photoreceptor drum 71 holds the toner image (developer image) developed by the developer unit 75. The photoreceptor drum 71 rotates to move the toner image to the transfer position on the transfer belt 91.

[0038] The transfer mechanism 42 transfers the toner image formed on the surface of the photoreceptor drum 71 to the printing medium P. In the configuration example shown in Figure 1, the transfer mechanism 42 includes a transfer belt (transfer body) 91, a drive roller 92, a plurality of primary transfer rollers (transfer devices) 93, and a secondary transfer roller 94.

[0039] The transfer belt 91 is a medium (transfer body) onto which the toner image formed on the surface of the photoreceptor drum 71 of each image forming station 41 is transferred. The transfer belt 91 is an intermediate transfer body that holds the image to be transferred to the printing medium P. In the configuration example shown in Figure 1, the transfer belt 91 is an endless belt wound around the drive roller 92 and a plurality of winding rollers. The back surface of the transfer belt 91, which is the inner surface, is in contact with the drive roller 92 and the plurality of winding rollers. The front surface of the transfer belt 91, which is the outer surface, faces the photoreceptor drum 71 of each image forming station 41.

[0040] The drive roller 92 rotates due to power transmitted from the drive mechanism. The drive roller 92 conveys the transfer belt 91 by rotating. In the configuration example shown in Figure 1, the drive roller 92 rotates counterclockwise. The rotation of the drive roller 92 conveys the transfer belt 91, which is an endless belt, so that it rotates counterclockwise. Multiple winding rollers are configured to rotate freely. Multiple winding rollers rotate in accordance with the movement of the transfer belt 91 by the drive roller 92.

[0041] Multiple primary transfer rollers (transfer units) 93 are provided for each image forming station 41. Each primary transfer roller 93 is positioned to face the photoreceptor drum 71 of the corresponding image forming station 41. Each primary transfer roller 93 is positioned to face the photoreceptor drum 71 of the corresponding image forming station 41, with the transfer belt 91 in between. The position where the primary transfer rollers 93 face the photoreceptor drum 71 with the transfer belt 91 in between is called the primary transfer section. In the primary transfer section, the image (toner image) on the photoreceptor drum 71 is transferred to the transfer belt 91.

[0042] The primary transfer roller 93 contacts the inner circumferential surface of the transfer belt 91. The primary transfer roller 93 presses the transfer belt 91 from the inner circumferential surface toward the photoreceptor drum 71. The surface (outer circumferential surface) of the transfer belt 91 pressed by the primary transfer roller 93 is in contact with the photoreceptor drum 71. When transferring an image (toner image) from the photoreceptor drum 71, the primary transfer roller 93 applies a transfer bias to the photoreceptor drum 71 via the transfer belt 91. The toner image from the photoreceptor drum 71 is transferred to the transfer belt 91 by the transfer bias applied by the primary transfer roller 93.

[0043] The secondary transfer roller 94 is positioned opposite the drive roller 92. The secondary transfer roller 94 contacts the surface of the transfer belt 91, whose inner surface is conveyed by the drive roller 92. The secondary transfer roller 94 presses the transfer belt 91 toward the drive roller 92. The transfer belt 91, sandwiched between the drive roller 92 and the secondary transfer roller 94, has its surface in close contact with the secondary transfer roller 94. A transfer nip is formed at the point where the surface of the transfer belt 91 and the secondary transfer roller 94 are in close contact. The transfer nip is a transfer area (transfer position) that transfers the toner image (developer image) formed on the surface of the transfer belt 91 to the printing medium P.

[0044] The secondary transfer roller 94 transports the printing medium P supplied by the resist roller 36, sandwiching it between itself and the transfer belt 91. The printing medium P passes through the transfer nip (transfer position). The secondary transfer roller 94 presses the printing medium P, as it passes through the transfer nip, against the surface of the transfer belt 91.

[0045] The secondary transfer roller 94 applies a bias voltage (secondary transfer bias) to the transfer belt 91 via the printing medium P at the transfer nip. The secondary transfer roller 94 applies a secondary transfer bias (hereinafter also simply referred to as transfer bias) at a potential specified by the system controller 13. When the printing medium P passes through the transfer nip with the secondary transfer roller 94 applying the transfer bias, the toner image on the transfer belt 91 is transferred to the printing medium P.

[0046] The density of the toner image transferred from the transfer belt 91 to the printing medium P as it passes through the transfer nip is set by the value of the transfer bias applied by the secondary transfer roller 94. The system controller 13 controls the density of the toner image transferred to the printing medium P by setting a transfer bias according to the result of processing the RFID tag on the printing medium P (tag processing).

[0047] If the tagging process is completed successfully, the system controller 13 sets the secondary transfer bias to the setting value for normal printing. When the secondary transfer bias is set to the setting value for normal printing, the toner image on the transfer belt 91 is transferred to the printing medium P at the density for normal printing (normal density). If the tagging process is not completed successfully, the system controller 13 sets the secondary transfer bias to the setting value for abnormal processing. When the secondary transfer bias is set to the setting value for abnormal processing, the toner image on the transfer belt 91 is transferred to the printing medium P at a density different from the density for normal printing (abnormal density).

[0048] In the primary transfer section, the transfer mechanism 42 transfers the toner image on the photoreceptor drum 71 to the transfer belt 91 that contacts the photoreceptor drum 71 by a transfer bias applied from the primary transfer roller 93 (primary transfer). If there are multiple image forming stations 41, the transfer mechanism 42 performs primary transfer of the toner image from the photoreceptor drum 71 of the multiple image forming stations 41 to the transfer belt 91.

[0049] The transfer mechanism 42 moves the toner image, which has been primarily transferred to the surface of the transfer belt 91, to the transfer nip (secondary transfer position). The transfer mechanism 42 then transfers the toner image transferred to the surface of the transfer belt 91 to the printing medium P, which passes through the transfer nip where the secondary transfer roller 94 applies a transfer bias. The transfer belt 91 is an example of an image carrier that holds the toner image to be transferred to the printing medium P.

[0050] Next, the configuration of the control system in the image forming apparatus 1 according to this embodiment will be described. Figure 2 is a block diagram showing an example of the control system configuration in the image forming apparatus 1. As shown in Figure 2, the image forming apparatus 1 connects a communication interface 12, an image forming mechanism 17, a fuser 18, a tag communication device 19, a scanner 20, a control panel 21, and a motor 30, etc., to a system controller (hereinafter also simply referred to as the controller) 13.

[0051] The controller 13 includes a processor 131, a ROM (Read Only Memory) 132, a RAM (Random Access Memory) 133, and an auxiliary storage device 134. The controller 13, along with the processor 131, ROM 132, RAM 133, and auxiliary storage device 134, constitutes a computer. The controller 13 may also include an ASIC, such as an image processing processor.

[0052] The processor 131 corresponds to the central part of the computer as the controller 13. The processor 131 controls each part of the image forming apparatus 1 according to the operating system or application program. The processor 131 is, for example, a CPU (Central Processing Unit).

[0053] ROM 132 and RAM 133 correspond to the main memory portion of the computer acting as the controller 13. ROM 132 is a non-volatile memory area, and RAM 133 is a volatile memory area. ROM 132 stores the operating system or application programs. ROM 132 stores control data necessary for the processor 131 to perform processing to control each part. RAM 133 is used as a work area where data is rewritten as appropriate by the processor 131. RAM 133 has a work area for storing, for example, image data.

[0054] The auxiliary storage device 134 corresponds to the auxiliary storage portion of the computer acting as the controller 13. The auxiliary storage device 134 is composed of, for example, a storage device such as EEPROM (Electric Erasable Programmable Read-Only Memory), HDD (Hard Disc Drive), or SSD (Solid State Drive). The auxiliary storage device 134 stores data such as configuration data used by the processor 131 when performing various processes. The auxiliary storage device 134 stores data generated by processes executed by the processor 131. The auxiliary storage device 134 may also store application programs.

[0055] For example, the auxiliary storage device 134 stores setting information (transfer setting information) for transferring the developer image on the transfer belt 91 to the printing medium P as setting data. The transfer setting information will have different setting values ​​depending on whether the processing of the RFID tag on the printing medium P (hereinafter referred to as tag processing) is completed successfully or not. The auxiliary storage device 134 stores multiple sets of transfer setting information corresponding to various transfer settings. The transfer setting information includes the setting value of the secondary transfer bias applied by the secondary transfer roller 94 at the transfer nip (transfer position).

[0056] For example, the auxiliary storage device 134 stores transfer setting information for when the tagging process is completed successfully and transfer setting information for when the tagging process is not completed successfully. The transfer setting information for when the tagging process is completed successfully includes a transfer bias setting value for transferring the developer image to the printing medium P at a predetermined density. The transfer setting information for when the tagging process is not completed successfully includes a transfer bias setting value for transferring the developer image to the printing medium P at a density different from the predetermined density.

[0057] The controller 13 connects to the toner cartridge 2, photoreceptor drum 71, cleaner 72, charger 73, exposure unit 74, and developer unit 75 in each image forming station 41. The controller 13 controls the toner cartridge 2, photoreceptor drum 71, cleaner 72, charger 73, exposure unit 74, and developer unit 75. For example, the controller 13 controls the on / off switching of the charger 73 in each image forming station 41. The controller 13 controls the on / off switching of the laser light that irradiates the photoreceptor drum in the exposure unit 74 of each image forming station 41. The controller 13 also controls the on / off switching of the development bias in the developer unit 75 of each image forming station 41.

[0058] The controller 13 is connected to the transfer mechanism 42. The transfer mechanism 42 includes a transfer belt 91, a drive roller 92, a plurality of primary transfer rollers 93, a secondary transfer roller 94, a power supply 95, and a power supply 97. The plurality of primary transfer rollers 93 are primary transfer rollers provided at each image forming station 41.

[0059] The power supply 95 supplies the transfer bias (primary transfer bias) that the primary transfer roller 93 applies to the photoreceptor drum 71, which is facing the transfer belt 91. The power supply 95 may be a current source or a voltage source.

[0060] The power supply 95 is connected to the controller 13. The controller 13 controls the on / off state of the primary transfer bias that the primary transfer roller 93 applies to the photoreceptor drum 71 via the power supply 95. The controller 13 controls the value of the primary transfer bias applied by the primary transfer roller 93 via the power supply 95.

[0061] The power supply 97 supplies the transfer bias (secondary transfer bias) that the secondary transfer roller 94 applies to the drive roller 92, which is opposite the transfer belt 91. The power supply 97 is connected to the controller 13. The controller 13 controls the on / off state of the transfer bias applied by the secondary transfer roller 94 using the power supply 97. The controller 13 controls the value of the transfer bias applied by the secondary transfer roller 94 using the power supply 97. For example, the controller 13 determines the value of the transfer bias based on the transfer settings corresponding to the processing results for the RFID tag on the printing medium P. Alternatively, the controller 13 may adjust the value of the transfer bias according to the basis weight, thickness, or type of the printing medium P.

[0062] Motor 30 is a motor that operates each part. Motor 30 is connected to the controller 13. Motor 30 is driven according to the control from the controller 13. Motor 30 includes, for example, a first motor, a second motor, and a third motor. The first motor, as motor 30, drives the transport mechanism 16. The second motor, as motor 30, rotates the photoreceptor drum 71. The third motor, as motor 30, rotates the drive roller 92. Multiple second motors are provided corresponding to the photoreceptor drums 71 provided in each of the multiple image forming stations 41. Motor 30 may also include motors other than the first, second, and third motors.

[0063] Next, an image forming system 200 having an image forming apparatus 1 and a server 201 according to an embodiment will be described. The image forming apparatus 1 having the configuration described above may be operated in an image forming system 200 connected to a server 201. For example, the server 201 may be operated as a management device that manages the data recorded on the RFID tags of the printing medium P in order to manage the printing medium P. The server 201 may also instruct the image forming apparatus 1 to write the data to the RFID tags of the printing medium P.

[0064] Server 201 can manage the processing history of the print medium P by saving the data written by the image forming apparatus 1 to the RFID tag of the print medium P along with information such as the date and time. Server 201 also acquires the data read by the image forming apparatus 1 from the RFID tag of the print medium P. Server 201 can manage the processing history of the print medium P by saving the data read by the image forming apparatus 1 from the RFID tag of the print medium P along with information such as the date and time.

[0065] Figure 3 is a block diagram showing an example configuration of an image forming system 200 having an image forming apparatus 1 and a server 201 according to an embodiment. In the configuration example shown in Figure 3, the image forming apparatus 1 is a digital multifunction device having the configuration shown in Figures 1 and 2. Also, in the configuration example shown in Figure 3, the server 201 has a processor 211, ROM (Read Only Memory) 212, RAM (Random Access Memory) 213, data memory 214, and a communication interface 215.

[0066] The processor 211 corresponds to the central part of the computer as a server 201. The processor 211 is, for example, a CPU (Central Processing Unit). The processor 211 performs various processes by executing programs. For example, the processor 211 executes an operating system or application program.

[0067] ROM212 and RAM213 correspond to the main memory portion of the computer as a server 201. ROM212 is a non-volatile memory area. RAM212 is a volatile memory area. ROM212 stores, for example, the operating system or application programs. ROM212 stores control data necessary for the processor 211 to perform processing to control each part. RAM213 is used as a work area where data is rewritten as appropriate by the processor 211. RAM213 has a work area for storing, for example, image data.

[0068] The data memory 214 corresponds to the auxiliary storage portion of the computer as a server 201. The data memory 214 is composed of a storage device such as an EEPROM (Electric Erasable Programmable Read-Only Memory), an HDD (Hard Disk Drive), or an SSD (Solid State Drive). The data memory 214 stores data such as configuration data used by the processor 211 when performing various processes. The data memory 214 stores data generated by the processes executed by the processor 211. The data memory 214 may also store application programs.

[0069] The data memory 214 may store information stored in the RFID tags on the printing medium P processed by the image forming apparatus 1. For example, the data memory 214 may store data written by the image forming apparatus 1 to the RFID tags of the printing medium P, along with information such as the date and time. Alternatively, the server 201 may store data read by the image forming apparatus 1 from the RFID tags of the printing medium P, along with information such as the date and time.

[0070] The communication interface 215 is an interface for communicating with other devices connected via a network. The communication interface 215 is used for communication with the image forming apparatus 1. For example, the communication interface 215 is an interface for LAN communication. Alternatively, the communication interface 215 may be an interface for wireless communication with other devices using standards such as Bluetooth or Wi-Fi.

[0071] Next, the image forming process and tagging process for a printing medium P equipped with an RFID tag in the image forming apparatus 1 according to the embodiment will be described. The image forming apparatus 1 performs two processes for a single print job: an image forming process to print an image onto a printing medium P, and a process (tagging) for the RFID tag on the printing medium P. The system controller 13 of the image forming apparatus 1 controls the value of the secondary transfer bias in the image forming process according to the result of the tagging process.

[0072] Figures 4, 5, and 6 show the transitions in the bias voltage (potential) applied to the secondary transfer roller 94 from the time the image forming apparatus 1 feeds the printing medium P until the transfer control is completed. In Figures 4 to 6, time Ta is the timing when paper feeding of the print medium P from tray 14 begins. Time Tb is the timing when tag processing of the RFID tag on the print medium P begins using the tag communication device 19. Time Tc is the timing when the predetermined time during which tag processing is possible (the time limit for tag processing) ends. The time from time Tb to time Tb (time Tb-Tc) is the period during which processing is performed on the RFID tag on the print medium P.

[0073] Alternatively, the tagging process may be performed with the printing medium P stopped at a predetermined position (standby position) in front of the registration roller 36. When the tagging process is performed with the printing medium P stopped at the standby position, time Tb is the timing when the printing medium P reaches the registration roller 36. Time Tc is the timing when the registration roller 36 is activated (turned on) (the timing when the registration roller 36 starts transporting the printing medium P to the transfer position). In this case, time Ta-Tb is the period during which the printing medium P is transported from the tray 14 to the standby position in front of the registration roller 36.

[0074] Time Td is the timing when the printing medium P reaches the secondary transfer position (also simply called the transfer position). Time Te is the timing when the printing medium P has finished passing through the secondary transfer position. Time Td-Te is the period during which the printing medium P passes through the secondary transfer position. The transfer bias applied by the secondary transfer roller 94 must be changed to the value of the transfer bias information in the transfer settings before the printing medium P reaches the secondary transfer position. Therefore, the timing for changing to the value of the transfer bias information in the transfer settings is between time Tc and time Td. Also, time Tf is the timing when the transfer control operation ends.

[0075] Figure 4 shows an example of the transition of the bias voltage (potential of the secondary transfer roller 94) applied to the secondary transfer roller 94 when the tagging process is completed successfully. When a print job is started, the potential applied to the secondary transfer roller 94 as a bias voltage is set to a predetermined potential (hereinafter referred to as the suppression potential) Va of the positive electrode. The suppression potential Va is a bias voltage set to suppress the adhesion of toner to the secondary transfer roller 94. For example, even if toner adheres to the transfer belt 91 due to some factor, the suppression potential Va suppresses the adhesion of toner to the secondary transfer roller 94.

[0076] In the example shown in Figure 4, the secondary transfer roller 94 maintains the applied bias voltage at the suppression potential Va during the time interval Ta-Tc. Between time Tc and time Td, the bias voltage applied by the secondary transfer roller 94 transitions to the transfer bias Vb normally used for printing. Figure 4 shows the transfer bias (print bias) Vb required to transfer the toner image on the transfer belt 91 to the printing medium P at normal density when the tagging process is completed successfully. For example, the transfer bias Vb shown in Figure 4 may be set to apply the maximum negative voltage to transfer the toner image to the printing medium P at normal density.

[0077] When the tagging process is successfully completed, the processor 131 sets up the transfer settings (normal density transfer settings) to transfer the toner image on the transfer belt 91 to the printing medium P at normal density. When the tagging process is successfully completed, the processor 131 reads the transfer setting information for the normal density transfer settings from the auxiliary storage device 134. The normal density transfer setting information includes information indicating the transfer bias Vb for transferring the toner image on the transfer belt 91 to the printing medium P at normal density. The processor 131 instructs the secondary transfer roller 94, which acts as a transfer device, to use the transfer bias Vb included in the normal density transfer setting information. The processor 131 also instructs the transfer bias Vb to be switched to the suppression potential Va between time Te and time Tf.

[0078] As shown in Figure 4, the secondary transfer bias, which is set to the suppression potential Va at times Ta-Tc, transitions to the transfer bias Vb before time Td when the tagging process is completed successfully. Furthermore, the secondary transfer bias, which is set to transfer bias Vb, transitions back to the suppression potential Va after time Te has elapsed. As a result, while the printing medium P passes through the transfer position, the secondary transfer bias becomes the transfer bias Vb that transfers the toner image on the transfer belt 91 to the printing medium P at the normal density.

[0079] Figure 5 shows an example of the bias voltage transition (first transition example) applied by the secondary transfer roller 94 when the tagging process does not complete successfully. In the example shown in Figure 5, the secondary transfer roller 94 maintains the applied bias voltage at the suppression potential Va during the time interval Ta-Tc, similar to Figure 4. The processor 131 determines whether the tagging process performed during the time interval Tb-Tc has been completed successfully. In the example shown in Figure 5, the processor 131 determines that the tagging process has not been completed successfully. If the tagging process has not been completed successfully, the processor 131 performs a transfer setting (abnormal density transfer setting) to transfer the toner image on the transfer belt 91 to the printing medium P at a density different from the normal density (abnormal density).

[0080] If the tagging process does not complete successfully, the processor 131 reads transfer setting information indicating the abnormal density transfer setting from the auxiliary storage device 134. The abnormal density transfer setting information includes information indicating the set value (potential) Vc of the transfer bias for transferring the toner image on the transfer belt 91 to the printing medium P at an abnormal density. The processor 131 instructs the secondary transfer roller 94, which acts as a transfer device, to use the transfer bias Vc included in the abnormal density transfer setting information. As a result, the secondary transfer bias, which is an inhibitory potential Va at times Ta-Tc, transitions to the transfer bias Vc before time Td, as shown in Figure 5.

[0081] Furthermore, the processor 131 instructs the system to switch the transfer bias Vc to the suppression potential Va after the printing medium P has passed the transfer position (between time Te and time Tf). As a result, the secondary transfer bias, which was set to transfer bias Vb, transitions to the suppression potential Va after time Te has elapsed.

[0082] In the example shown in Figure 5, the transfer bias Vc is set to the potential of the positive electrode, which is the opposite of the transfer bias (printing bias) Vb that transfers the toner image at normal density. For example, the transfer bias Vc may also be set to the maximum voltage at the opposite electrode (positive electrode) to the transfer bias (printing bias) Vb.

[0083] When the transfer bias applied by the secondary transfer roller 94 is set to the positive potential, the toner on the transfer belt 91 is less likely to be transferred. However, since the transfer belt 91 and the printing medium P are in contact at the transfer position, even if the secondary transfer bias is set to the maximum voltage of the reverse (positive) electrode, the toner image on the transfer belt 91 is still faintly transferred to the printing medium P. In other words, when the transfer bias is set to the reverse (positive) electrode voltage, which is the transfer bias (printing bias) Vb, the density of the image transferred to the printing medium P becomes fainter.

[0084] The transfer bias Vc should be set to a level that allows a person to visually perceive that the density of the toner image transferred to the printing medium P is clearly different from the normal density. For example, the transfer bias Vc may be the suppression potential Va, or it may be a negative electrode potential smaller than the transfer bias Vb.

[0085] As shown in Figure 5, by changing the secondary transfer bias, an image with a lighter density than the normal density during normal printing is transferred to the print medium. A print medium with a lighter image clearly indicates that the processing for the RFID tag has failed. Users can reliably distinguish print mediums with failed RFID tag processing by visually inspecting the lighter image transferred to the print medium.

[0086] Figure 6 shows an example of the bias voltage transition (second transition example) applied by the secondary transfer roller 94 when the tagging process does not complete successfully. In the example shown in Figure 6, the secondary transfer bias is controlled so that it alternates between the negative electrode potential Ve and the opposite electrode (positive electrode) potential Vd during the period when the printing medium P passes through the transfer position. Due to the fluctuation in the secondary transfer bias, the toner image on the transfer belt 91 is transferred to the printing medium with variations in density.

[0087] The negative electrode potential Ve shown in Figure 6 may be the same value as the transfer bias Vb shown in Figure 4. The positive electrode potential Vd shown in Figure 6 may be the same value as the transfer bias Vc shown in Figure 5. Furthermore, the switching between the positive electrode potential Vd and the negative electrode potential Ve should be done within a controllable range. For example, the timing of the switching between the positive electrode potential Vd and the negative electrode potential Ve should be the time required for the bias voltage to switch. Alternatively, the switching between the positive electrode potential Vd and the negative electrode potential Ve may be performed every rotation of the secondary transfer roller 94. Furthermore, the switching between the positive electrode potential Vd and the negative electrode potential Ve does not have to be at predetermined cycles.

[0088] As shown in Figure 6, varying the secondary transfer bias results in a printable image with varying shades of gray being transferred to the print medium. A printable medium with such a grayscale image clearly indicates that the processing of the RFID tag failed. Users can easily recognize a printable medium as having failed to process the RFID tag by visually inspecting the grayscale image transferred to it.

[0089] Next, the image forming process (printing process) for a printing medium P equipped with an RFID tag in the image forming apparatus 1 according to the embodiment will be described. Figure 7 is a flowchart illustrating the processing flow for a print medium P equipped with an RFID tag in the image forming apparatus 1 according to this embodiment. The image forming apparatus 1 receives print jobs from an external device connected to the communication interface 12 or print jobs input to the control panel 21. Here, the image forming apparatus 1 receives print jobs from an external device that include tagging and image forming processes for a print medium P equipped with an RFID tag. In the processing example shown in Figure 7, the tagging process included in the print job is assumed to be a write process that writes data to the RFID tag on the print medium P.

[0090] When the processor 131 executes a received print job, it acquires image data to be printed on the print medium P equipped with an RFID tag (ACT11). For example, the processor 131 acquires image data received from an external device along with the print job via the communication interface 12.

[0091] Furthermore, the processor 131 acquires data (write data) to be written to the RFID tag of the print medium P as part of the tag processing included in the print job (ACT 12). For example, the processor 131 acquires the write data along with the print job received from an external device via the communication interface 12. Alternatively, the processor 131 may acquire the write data to be written to the RFID tag of the print medium P, which prints image data from an external device, from the server 201.

[0092] When the processor 131 acquires image data to be printed on the printing medium P, it starts an image generation process in which the image forming mechanism 17 forms a developer image on the transfer belt 91 (ACT 13). For example, if the image data is a color image, the processor 131 transfers the developer images of each color generated by the respective color image forming stations onto the transfer belt 91. If the image data is a black image, the processor 131 transfers the black developer image generated by the black image forming station onto the transfer belt 91.

[0093] Furthermore, the processor 131 takes in a print medium P equipped with an RFID tag to be used for processing the print job to be executed (ACT 14). For example, the processor 131 takes in a print medium P equipped with an RFID tag from the tray 14. The processor 131 transports the print medium P taken in from the tray 14 to the front of the registration roller 36.

[0094] When the processor 131 transports the printing medium P to the registration roller 36, it performs tag processing using the tag communication device 19 to process the RFID tag on the printing medium P (ACT15-17). In the example processing shown in Figure 4, the tag processing is assumed to be a write process in which data is written to the RFID tag.

[0095] As part of the writing process, the processor 131 first reads the information recorded on the RFID tag of the print medium P using the tag communication device 19 (ACT 15). For example, the processor 131 communicates with the RFID tag of the print medium P using the tag communication device 19. The tag communication device 19 outputs radio waves containing a command requesting a response from the RFID tag in response to instructions from the processor 131. RFID tags within the communication range of the tag communication device 19 are activated by the radio waves from the tag communication device 19. The activated RFID tag outputs information (e.g., identification information) as a response to the command contained in the radio waves from the tag communication device 19. The tag communication device 19 receives the response from the RFID tag and supplies the received data to the processor 131.

[0096] When the processor 131 reads an RFID tag using the tag communication device 19, it requests the RFID tag to write data (ACT 16). For example, the tag communication device 19 outputs a radio wave to the RFID tag containing a command (write command) requesting the writing of data supplied by the processor 131. The RFID tag executes the process of writing the data to its internal memory in accordance with the write command from the tag communication device 19. When the writing of the data is complete, the RFID tag outputs a response indicating that the writing is complete. The tag communication device 19 receives the response indicating that the writing is complete from the RFID tag and notifies the processor 131 that the writing is complete.

[0097] When the processor 131 receives notification from the tag communication device 19 that writing is complete, it requests the RFID tag to read the data written to its internal memory (ACT 16). For example, the tag communication device 19 outputs a radio wave to the RFID tag that includes a command (verify read command) requesting the reading of the data recorded in its internal memory in response to an instruction from the processor 131. The RFID tag reads the data recorded in its internal memory according to the read command from the tag communication device 19. The RFID tag outputs the data read from its internal memory as a response to the read command. The tag communication device 19 receives a response that includes the data read from the RFID tag's internal memory. The tag communication device 19 supplies the data received from the RFID tag to the processor 131.

[0098] When the series of tagging operations on the RFID tag of the printed medium P is completed, the processor 131 determines whether the tagging operations were successfully performed (ACT 17). For example, the processor 131 determines whether the tagging operations (writing operations) were successfully completed by checking whether the written data that was instructed to be written matches the data read after the writing operations. The processor 131 determines that the writing operations were successfully completed if the written data and the read data match. The processor 131 also determines that the writing operations were not successfully completed if the written data and the read data do not match.

[0099] If the processor determines that the tagging process did not complete successfully (ACT17, NO), it determines whether it is within the predetermined time (the time limit for tagging) (ACT18). If the processor determines that it did not complete successfully and it is within the predetermined time (ACT18, YES), it repeats the processes of ACT15-17.

[0100] If the tagging process is completed successfully (ACT17, YES), the processor 131 sets transfer control settings based on transfer setting information (first control value) for transferring the toner image to the printing medium P at a normal density (ACT20). The first control value includes information indicating the value (potential) of the transfer bias (print bias) for transferring the toner image formed on the transfer belt 91 to the printing medium P at a normal density.

[0101] The transfer bias (printing bias) for transferring at normal concentration is, for example, the maximum voltage Vb of the negative electrode, as shown in Figure 4. The processor 131 sets the transfer bias (printing bias) Vb indicated by the normal concentration transfer setting information to the secondary transfer roller 94, which is the transfer device. The secondary transfer roller 94 applies the potential Vb specified by the processor 131 as the transfer bias.

[0102] Once the transfer bias is set based on the transfer setting information for normal density, the processor 131 transports the printing medium P to the transfer position. The processor 131 transfers the toner image on the transfer belt 91 to the printing medium P at normal density by passing it through the transfer position to which the transfer bias for normal density transfer has been applied (ACT21).

[0103] The processor 131 transports the printing medium P, on which the toner image has been transferred at the correct density as it passes through the transfer position, to the fuser 18. The fuser 18 fixes the toner image, which has been transferred at the correct density, to the printing medium P by heating and pressurizing it with the heat roller 34 and the pressure roller 35.

[0104] The processor 131 transports the printing medium P, on which the toner image transferred at the normal density by the fuser 18 has been fixed, to the discharge unit. The processor 131 discharges the printing medium P, on which the toner image at the normal density has been transferred and fixed, to a specified position specified by the print job (ACT22).

[0105] If the tagging process does not complete successfully (ACT17, NO), the processor 131 sets the transfer settings to transfer the toner image to the printing medium P at a density other than the normal density (abnormal density) (ACT20). Here, the processor 131 sets the transfer bias based on the abnormal density transfer setting information (second control value).

[0106] The second control value includes information indicating the setting value of the transfer bias for transferring the toner image formed on the transfer belt 91 to the printing medium P at an abnormal density. The setting value for the transfer bias when transferring at an abnormal concentration is, for example, the maximum voltage Vc of the reverse electrode (negative electrode) as shown in Figure 5. In this case, the processor 131 sets the transfer bias Vc indicated by the transfer setting information for the abnormal concentration to the secondary transfer roller 94, which is the transfer device. As a result, the secondary transfer roller 94 applies the potential Vc specified by the processor 131 as the transfer bias.

[0107] Furthermore, the setting value for the transfer bias that transfers at an abnormal concentration may be one in which the maximum potential Vd of the reverse electrode (positive electrode) and the potential Ve of the negative electrode are alternately applied, as shown in Figure 6. In this case, the processor 131 sets the secondary transfer roller 94, which is the transfer device, to alternately apply the transfer bias with potential Vc and potential Ve. As a result, the secondary transfer roller 94 alternately applies the transfer bias with potential Vc and potential Ve as specified by the processor 131.

[0108] Based on the transfer setting information for abnormal density, the processor 131 sets the transfer bias and transports the printing medium P to the transfer position. The processor 131 transfers the toner image on the transfer belt 91 to the printing medium P at an abnormal density by passing it through the transfer position to which the transfer bias for abnormal density transfer has been applied (ACT24).

[0109] The processor 131 transports the printing medium P, on which the toner image has been transferred at an abnormal density as it passes through the transfer position, to the fuser 18. The fuser 18 heats and pressurizes the printing medium P using the heat roller 34 and the pressure roller 35 to fix the toner image that was transferred at an abnormal density to the printing medium P.

[0110] The processor 131 transports the printing medium P, on which the abnormally dense toner image has been fixed by the fuser 18, to the discharge unit. The processor 131 discharges the printing medium P, on which the abnormally dense toner image has been transferred and fixed, to a discharge position other than the designated position specified by the print job (ACT25).

[0111] Note that the tag processing in ACT15-17 may be a process other than writing. The processor 131 only needs to determine whether the tag processing has been completed successfully by checking whether or not normal data exchange occurred between the tag communication device 19 and the RFID tag. If the tag processing is a reading process, the processor 131 will determine that there is an abnormality if there is no response from the RFID tag or if the response from the RFID tag is not in a normal data format.

[0112] As described above, the image forming apparatus according to the embodiment uses a medium equipped with a wireless tag as the printing medium. The image forming apparatus controls the operation of the transfer unit with transfer setting information that transfers a toner image to the printing medium at a normal density when communication between the communication device and the wireless tag of the printing medium is successfully performed. The image forming apparatus controls the operation of the transfer unit with transfer setting information that transfers a toner image to the printing medium at an abnormal density when communication between the communication device and the wireless tag of the printing medium is not successfully completed.

[0113] This allows for easy control of the transfer unit by changing the transfer settings, enabling the printing of images at abnormal density on print media where the wireless tag did not function correctly. As a result, print media where the wireless tag did not function correctly can be clearly identified by the density of the printed image.

[0114] In the embodiments described above, a digital multifunction device equipped with an electrophotographic printer was used as an example of an image forming apparatus. However, the image forming apparatus according to the embodiment only needs to be capable of changing the density of the image formed on the print medium according to the processing result of the RFID tag on the captured print medium. In other words, the embodiments described above are not limited to being applied to electrophotographic image forming apparatuses, but may also be applied to image forming apparatuses using image forming methods other than electrophotography.

[0115] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. The following is an appendix to the claims originally filed for this application. [1] A communication device that communicates with wireless tags, A transfer device that transfers a developer image formed with a developer onto a medium equipped with a wireless tag that communicates with the aforementioned communication device, A processor that controls the operation of the transfer device with a first control value when communication with the wireless tag by the communication device is successfully performed, and controls the operation of the transfer device with a second control value different from the first control value when communication with the wireless tag by the communication device is not successfully completed, An image forming apparatus having [2] The first control value is a control value for the transfer unit to perform the operation of transferring the developer image to the medium at a predetermined concentration. The second control value is a control value for the transfer unit to perform the operation of transferring the developer image onto the medium at a concentration different from the predetermined concentration. [1] The image forming apparatus described above. [3] The processor, if communication with the wireless tag by the communication device fails to complete successfully, varies the second control value during the period in which the transfer unit transfers the developer image onto the medium. [2] The image forming apparatus described above. [4] The transfer device transfers the developer image on the transfer body to the medium by applying a bias voltage of a value set according to the control value from the processor. The first control value includes a first bias voltage value for the transfer device to transfer the developer image on the transfer body to the medium at a predetermined concentration. The second control value includes a second bias voltage value different from the first bias voltage value for the transfer device to transfer the developer image on the transfer medium to a concentration different from the predetermined concentration, [2] The image forming apparatus described above. [5] The second bias voltage value is the opposite of the first bias voltage value. [4] The image forming apparatus described above. [Explanation of Symbols]

[0116] 1…Image forming apparatus, 11…Housing, 12…Communication interface, 13…System controller (controller), 14…Paper tray, 15…Output tray, 16…Transport mechanism, 17…Image forming mechanism, 18…Fuser, 19…Tag communication device (communication device), 21…Control panel, 31…Paper feed transport path, 32…Output transport path, 33…Pickup roller, 36…Registration roller, 41…Image forming station, 42…Transfer mechanism, 71…Photoreceptor drum (photoreceptor), 74…Explorer, 75…Developer, 91…Transfer belt, 91…Transfer belt, 92…Drive roller, 93…Primary transfer roller, 94…Secondary transfer roller (transfer unit), 131…Processor, 134…Auxiliary storage device.

Claims

1. A communication device that communicates with wireless tags, A transfer device that transfers a developer image formed with a developer onto a medium equipped with a wireless tag that communicates with the aforementioned communication device, A processor that controls the operation of the transfer device with a first control value if the data writing process to the wireless tag by the communication device is successfully completed within a predetermined time, and controls the operation of the transfer device with a second control value different from the first control value if the data writing process to the wireless tag by the communication device is not successfully completed within a predetermined time; An image forming apparatus having

2. The first control value is a control value for the transfer unit to perform the operation of transferring the developer image to the medium at a predetermined concentration. The second control value is a control value for the transfer unit to perform the operation of transferring the developer image onto the medium at a concentration different from the predetermined concentration. The image forming apparatus according to claim 1.

3. The processor alternately varies the second control value between two different values ​​during the period in which the transfer unit transfers the developer image onto the medium if the data writing process to the wireless tag by the communication device is not completed successfully within a predetermined time. The image forming apparatus according to claim 2.

4. The transfer device transfers the developer image on the transfer body to the medium by applying a bias voltage of a value set according to the control value from the processor. The first control value includes a first bias voltage value for the transfer device to transfer the developer image on the transfer medium at a predetermined concentration. The second control value includes a second bias voltage value different from the first bias voltage value for the transfer device to transfer the developer image on the transfer medium to a concentration different from the predetermined concentration, The image forming apparatus according to claim 2.

5. The second bias voltage value is the opposite value to the first bias voltage value. The image forming apparatus according to claim 4.

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