Patent Publication Number: US-2020293244-A1

Title: Image forming apparatus and image forming method

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2019-048817, filed on Mar. 15, 2019, the entire contents of which are incorporated herein by reference. 
     FIELD 
     Exemplary embodiments described herein relate to an image forming apparatus and an image forming method. 
     BACKGROUND 
     There is an image forming apparatus that writes information to a radio frequency identifier (RFID) tag attached to a sheet and also prints images on the sheet. Such an image forming apparatus can also read information that has been written to the RFID tag to determine whether writing of information to the RFID tag has been properly performed. If the RFID tag is not properly written with information, printing of an image indicating a writing error can be performed on the sheet. 
     However, if images are being continuously formed on a plurality of sheets or on both sides of a sheet, the image forming apparatus typically performs processing for forming different images in rapid succession. That is a process for forming an image different from the image to be used for indicating an error in tag writing may have already been started before the error in tag writing has been detected. For this reason, if the information read from the RFID tag is not normal/correct, the image forming apparatus may not be able to appropriately form the image indicating the error in tag writing. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates an external view of an image forming apparatus according to a first embodiment. 
         FIG. 2  is a block diagram illustrating a system configuration of an image formation system according to the first embodiment. 
         FIG. 3  is a block diagram illustrating a hardware configuration of the image forming apparatus according to the first embodiment. 
         FIG. 4  is a block diagram illustrating a hardware configuration of a write information server according to the first embodiment. 
         FIG. 5  depicts an internal configuration of the image forming apparatus according to the first embodiment. 
         FIG. 6  depicts a conveyance path of a sheet when information written on an RFID tag according to the first embodiment is normal. 
         FIG. 7  depicts a conveyance path of a sheet when information written to the RFID tag according to the first embodiment is not normal. 
         FIG. 8  is a flowchart illustrating a flow of processing of information written to the RFID tag according to the first embodiment. 
         FIG. 9  depicts an internal configuration of an image forming apparatus according to a second embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     An example embodiment provides an image forming apparatus and an image forming method which can form an image indicating that an RFID tag is abnormal or not correctly written even tag sheets are being processed quickly or being printed with images on both sides of the tag sheet. 
     In general, according to an embodiment, an image forming apparatus includes an RFID tag reader, an image forming unit, and a processor. The RFID tag reader is configured to read an RFID tag on a sheet conveyed along a conveyance path. The image forming unit including a developer carrier. The processor is configured to determine, based on information read by the RFID tag reader from the RFID tag, whether information written to the RFID is correct. The processor is configured to, when the writing has not been properly carried or the information is otherwise incorrect, cause the sheet to be conveyed to the image forming unit, a developer image already formed on the developer carrier to be removed, and then an alternative image indicating a tag writing error to be printed on the sheet. 
     An image forming apparatus and an image forming method according to certain example embodiment will be described with reference to the accompanying drawings. 
     First Embodiment 
       FIG. 1  illustrates an external view of an image forming apparatus  100  according to a first embodiment. The image forming apparatus  100  is, for example, a multifunction peripheral apparatus. The image forming apparatus  100  includes a display  110 , a control panel  120 , a printer unit  130 , a sheet accommodation unit  140 , and an image reading unit  200 . The printer unit  130  of the image forming apparatus  100  may be an electrophotographic apparatus that prints images by fixing a toner image to a sheet or may be an ink jet type apparatus. 
     The image forming apparatus  100  forms an image on a sheet using a developer such as toner. The sheet is, for example, paper, a tag sheet, or a label sheet. The sheet may be a sheet to which one or more RFID tag is attached or coupled. In general, the sheet may be any medium or material on which the image forming apparatus  100  can form an image on a surface thereof. Regarding the sheet to which the RFID tag is attached or coupled, the RFID tag may be attached onto a surface of the sheet or the RFID tag may be embedded within the sheet. 
     The display  110  is an image display device such as a liquid crystal display or an organic electro luminescence (EL) display. The display  110  displays various kinds of information regarding the image forming apparatus  100 . 
     The control panel  120  includes a plurality of buttons. The control panel  120  receives a user&#39;s operation. The control panel  120  outputs a signal according to an operation performed by the user to a control unit of the image forming apparatus  100 . The display  110  and the control panel  120  may be configured as an integrated touch panel. 
     The printer unit  130  forms an image on a sheet on the basis of image information generated by the image reading unit  200  or image information received through a communication path. The printer unit  130  forms an image through, for example, the following processing. The printer unit  130  forms an electrostatic latent image on a photoreceptor drum on the basis of image information. The printer unit  130  forms a visible image by attaching a developer to the electrostatic latent image. A specific example of the developer is a toner. The printer unit  130  transfers the visible image onto a sheet. The printer unit  130  fixes the visible image onto the sheet by heating and pressing the sheet. The sheet having the image formed thereon may be a sheet accommodated in the sheet accommodation unit  140  or may be a sheet manually supplied. 
     The sheet accommodation unit  140  accommodates sheets used to form an image in the printer unit  130 . 
     The image reading unit  200  reads image information to be read based on brightness and darkness of light. The image reading unit  200  records the read image information. The recorded image information may be transmitted to another information processing device through a network. The recorded image information may be formed on a sheet as an image by the printer unit  130 . 
       FIG. 2  is a block diagram illustrating a system configuration of an image formation system  1  according to the first embodiment. The image formation system  1  is provided in a network  400 . The image formation system  1  includes the image forming apparatus  100  and a write information server  300  which are communicatively connected to each other through the network  400 . The network  400  is a broadband communication network such as the Internet. The network  400  may be a network using wireless communication or may be a network using wired communication. The network  400  may comprises a plurality of networks being combined or otherwise interconnected with each other. 
     The write information server  300  comprises an information processing device such as a server or a personal computer. The write information server  300  supplies write information to be written to an RFID tag attached to a sheet in response to a request sent from the image forming apparatus  100 . The write information is information written to the RFID tag attached to the sheet. The write information is information such as a Japan Article Number (JAN) code or a serial number. The write information can be written in an electronic product code (EPC) area of the RFID tag through an antenna  154 . 
       FIG. 3  is a block diagram illustrating a hardware configuration of the image forming apparatus  100  according to the first embodiment. The image forming apparatus  100  includes the display  110 , the control panel  120 , the printer unit  130 , the sheet accommodation unit  140 , a storage device  151 , a memory  152 , a processor  153 , the antenna  154 , an external interface  155 , and the image reading unit  200 . The display  110 , the control panel  120 , the printer unit  130 , the sheet accommodation unit  140 , and the image reading unit  200  are described above, and thus description thereof will be omitted. Hereinafter, the storage device  151 , the memory  152 , the processor  153 , the antenna  154 , and the external interface  155  will be described. The functional units are connected to each other so as to be capable of communicating data through a system bus  160 . 
     The storage device  151  is, for example, a hard disk or a solid state drive (SSD), and stores various pieces of data. The various pieces of data are a printing job received from an external communication device or a software program for controlling operations of the functional units of the image forming apparatus  100 . The printing job may include information indicating which write information is acquired from the write information server  300 . The printing job may be a job related to both-side printing or may be a job related to printing of a plurality of sheets. The printing job may include image information related to an image printed on a sheet. 
     The memory  152  temporarily stores data used by the functional units included in the image forming apparatus  100 . The memory  152  is, for example, a random access memory (RAM). The memory  152  may store digital data generated by the image reading unit  200 . The memory  152  may temporarily store a printing job in which printing is performed by the printer unit  130  and write information to be written on an RFID tag which is received from the write information server  300 . 
     The processor  153  controls operations of the described functional units of the image forming apparatus  100 . The processor  153  executes processing by loading a software program stored in the storage device  151  onto the memory  152  and executing a software program. Here, one example of specific processing of the processor  153  will be described. The processor  153  controls the printing of a sheet to which an RFID tag is attached (RFID tag sheet). The printing is controlled by the processor  153  on the basis of a printing job received through an external communication device or the control panel  120 . When the processor  153  receives a printing job for a RFID tag sheet, the processor  153  acquires write information designated by the printing job and image information associated with the write information from the write information server  300 . The image information associated with the write information is information related to an image formed on the sheet. The image information is not necessarily directly associated with the write information. In this case, the image information is preferably included in the printing job. The processor  153  controls the sheet accommodation unit  140 . The sheet accommodation unit  140  supplies a RFID tag sheet (a sheet to which an RFID tag is attached). The processor  153  controls the printer unit  130 . The printer unit  130  prints image information acquired from the write information server  300  on a sheet. The processor  153  controls the antenna  154 . The antenna  154  writes write information on an RFID tag attached to a supplied sheet. The antenna  154  reads the write information written to the RFID tag. The processor  153  determines whether or not write information acquired from the write information server  300  and information read from an RFID tag are consistent with each other. If the write information acquired from the write information server  300  and the information read from the RFID tag are consistent with each other, the processor  153  controls a conveying roller (not shown) so as to discharge a sheet. If the write information acquired from the write information server  300  and the information read from the RFID tag are not consistent with each other, the processor  153  operates to print an image indicating an error writing on a sheet. After an image indicating the error writing is printed in accordance with controlling of the conveying roller, a sheet is discharged. 
     The antenna  154  performs writing of information on an RFID tag attached to a sheet. In addition, the antenna  154  performs reading of information from the RFID tag attached to the sheet. The antenna  154  writes write information acquired from the write information server  300  on the RFID tag attached to the sheet by operating as an RFID tag writing device. The antenna  154  reads information from the RFID tag by operating as an RFID tag reading device. The antenna  154  is provided downstream of the printer unit  130 . Since the antenna  154  is provided downstream of the printer unit  130 , writing and reading are performed on an RFID tag after being heated by the printer unit  130 . Therefore, by providing the antenna  154  downstream of the printer unit  130 , for example, when the RFID tag fails due to heating by the printer unit  130 , a failure can be detected. The antenna  154  is one form of an RFID tag reading unit and an RFID tag recording unit. The antenna  154  is configured to perform both writing and reading of information on an RFID tag, but is not limited thereto. For example, regarding the antenna  154 , an antenna for writing and an antenna for reading may be provided as different antennas. 
     The external interface  155  transmits and receives data to and from another device. Here, another device is an information processing device such as a personal computer, a tablet computer, or a smart device, or an information processing device such as the write information server  300 . The external interface  155  operates as an input interface and receives data or an instruction transmitted from the other device. The instruction transmitted from the other device is a printing job or the like. The data transmitted from the other device is write information, image information associated with the write information, or the like. In addition, the external interface  155  operates as an output interface and transmits data to the other device. 
       FIG. 4  is a block diagram illustrating a hardware configuration of the write information server  300  according to the first embodiment. The write information server  300  includes a storage device  301 , a memory  302 , a processor  303 , and an external interface  304 . The functional units are communicably connected to each other so as to be capable of communicating data through a system bus  305 . 
     The storage device  301  is, for example, a hard disk or an SSD, and stores various pieces of data. The various pieces of data can be write information to be written on an RFID tag or image information associated with the write information. The various pieces of data can also include a software program for controlling operations of the functional units of the write information server  300 . 
     The memory  302  temporarily stores data used by the functional units of the write information server  300 . The memory  302  is, for example, a RAM. 
     The processor  303  controls operations of the functional units of the write information server  300 . The processor  303  executes processing by loading a software program stored in the storage device  301  onto the memory  302  and executing the software program. Here, one possible example of specific processing of the processor  303  will be described. The processor  303  receives requests for write information and image information associated with the write information from the image forming apparatus  100  through the external interface  304 . The processor  303  transmits the requested write information and the image information associated with the write information to the image forming apparatus  100 . 
     The external interface  304  transmits and receives data to and from other devices. In this context, “other device” can be a device such as the image forming apparatus  100 . The external interface  304  operates as an input interface and receives data and/or an instruction transmitted from the other device(s). The instruction transmitted from the other device can be a request for write information, or the like. In addition, the external interface  304  operates as an output interface and transmits data to the other device(s). 
       FIG. 5  is a diagram illustrating a specific example of an internal configuration of the image forming apparatus  100  according to the first embodiment. The image forming apparatus  100  includes the printer unit  130 , the sheet accommodation unit  140 , the antenna  154 , a sheet discharging unit  156 , and a sheet reversing path  157 . The printer unit  130  includes an image forming unit  131  and a fixing unit  132 . The sheet accommodation unit  140  includes a sheet supply unit  141 . The sheet reversing path  157  includes a registration unit  158 . The printer unit  130 , the sheet accommodation unit  140 , and the antenna  154  are, in general, as described above, and thus additional description thereof will be omitted. Various aspects of the image forming unit  131 , the fixing unit  132 , the sheet supply unit  141 , the sheet discharging unit  156 , the sheet reversing path  157 , and the registration unit  158  will be described. 
     In this example, the image forming unit  131  includes a predetermined toner set. For example, the image forming unit includes a yellow toner, a cyan toner, a magenta toner, and a black toner from an upstream side (the left side in the drawing). In addition, the predetermined toner set may include a special toner such as a decolorable toner. The image forming unit  131  includes a developing unit, a photoreceptor drum, and a charging unit for each toner. The charging unit uniformly charges the photoreceptor layer of the photoreceptor drum. The photoreceptor drum can be irradiated with a laser beam to form an electrostatic latent image on the surface thereof. The developing unit performs development by supplying a toner to the electrostatic latent image. In addition, the image forming unit  131  includes a transfer belt. Images developed with the different toners are sequentially transferred to the transfer belt so as to overlap each other as necessary. The overlapping toner images are then transferred to a sheet using a transfer roller. Although an image forming method of an intermediate transfer system is described for the present embodiment, in other examples, a direct transfer system or other transfer systems may be used. 
     The fixing unit  132  includes a heating roller and a pressing roller. The heating roller applies heat to a sheet from one surface side of the sheet. The pressing roller applies pressure to the sheet from the other surface side of the sheet. The fixing unit  132  fixes the toner to the sheet by applying heat and pressure to the sheet. 
     The sheet supply unit  141  supplies sheets accommodated in the sheet accommodation unit  140 . The sheet supply unit  141  comprises, for example, a sheet supply roller. The sheet discharging unit  156  discharges sheets conveyed through the inside of the image forming apparatus  100 . The sheet discharging unit  156  comprises, for example, a sheet discharge roller. 
     The sheet reversing path  157  is a path for reversing a sheet in order to form an image on a surface on a side opposite to a surface of the sheet on which an image is formed (hereinafter, referred to as a “rear surface”). The sheet reversing path  157  is a path for reversing and conveying a sheet conveyed to the sheet discharging unit  156  by switchback. 
     The registration unit  158  is provided in the sheet reversing path  157 . In the first embodiment, description assumes that the registration unit  158  is a registration roller provided on the most downstream side of the sheet reversing path  157 . The registration unit  158  temporarily stops the conveyance of a sheet. When stopping the conveyance of the sheet, the registration unit  158  corrects an inclination of the sheet in a direction perpendicular to a conveyance direction. Note, in general, the location of the registration unit  158  is not limited to the most downstream side of the sheet reversing path  157 . The registration unit  158  may be provided at any location as long as the registration unit is provided along the path between the sheet discharging unit  156  and the sheet reversing path  157 . 
       FIG. 6  is a diagram illustrating a specific example of a conveyance path of a sheet when information written on an RFID tag according to the first embodiment is normal. First, a RFID tag sheet is supplied from the sheet accommodation unit  140 . The supplied sheet is conveyed to the printer unit  130 . An image is formed on the sheet by the printer unit  130 . The sheet having an image formed thereon is conveyed to the antenna  154 . Write information is written to the RFID tag of the sheet conveyed to the antenna  154  using the antenna  154 . The antenna  154  then reads information from the RFID tag. If the read information and the written information are consistent with each other, the processor  153  determines that the information of the RFID tag is normal. The sheet is conveyed to the sheet discharging unit  156  and discharged from the image forming apparatus  100 . 
       FIG. 7  is a diagram illustrating a specific example of a conveyance path of a sheet when information written on an RFID tag according to the first embodiment is not normal. First, a RFID tag sheet is supplied from the sheet accommodation unit  140 . The supplied sheet is conveyed to the printer unit  130 . An image is formed on the sheet by the printer unit  130 . The sheet having an image formed thereon is conveyed to the antenna  154 . Write information is written using the antenna  154  to the RFID tag of the sheet conveyed to the antenna  154 . The antenna  154  reads the information just written to the RFID tag. If the read information and the written information are inconsistent with each other, the processor  153  determines that the information written to the RFID tag is abnormal. When it is determined that the information from the RFID tag is not normal, the sheet is switched back from the sheet discharging unit  156  and conveyed to the sheet reversing path  157 . The sheet conveyed to the sheet reversing path  157  is temporarily stopped by the registration unit  158  (see  FIG. 5 ). When it is determined that the information written to the RFID tag is not normal, the printer unit  130  removes a developer for forming an image on the rear surface of the conveyed sheet or a sheet to be conveyed next from a developer carrier (e.g., a drum). The printer unit  130  performs development so that an image indicating an error in writing to the RFID tag (hereinafter, referred to as a “void image”) will be formed on at least one drum. The void image includes a indicative mark such as and/or a sentence such as “a process of performing writing on a tag was not normally completed”. The sheet which was temporarily stopped by the registration unit  158  is then conveyed to the printer unit  130  after a predetermined period of time elapses after the temporary stop. The predetermined period of time may be, for example, the period of time required until the printer unit  130  can form a void image. A void image is transferred to the sheet conveyed to the printer unit  130 . The sheet to which the void image is transferred is discharged from the sheet discharging unit  156  (after fixing). 
       FIG. 8  is a flowchart showing a flow of processing of information written on an RFID tag according to the first embodiment. The present flowchart is executed if a printing job for performing both-side printing on a RFID tag sheet is received. The processor  153  of the image forming apparatus  100  receives a printing job (ACT  101 ). Specifically, an external information processing device such as a personal computer transmits a printing job related to both-side printing to the image forming apparatus  100  through a network. The processor  153  of the image forming apparatus  100  receives a printing job through the external interface  155 . 
     The processor  153  acquires write information and image information associated with the write information (ACT  102 ). Specifically, when the processor  153  receives the printing job, the processor requests the write information and the image information associated with the write information from the write information server  300  through the external interface  155 . The write information server  300  transmits the requested write information and image information associated with the write information to the image forming apparatus  100 . 
     The printer unit  130  forms an image on one surface (front surface) of the conveyed sheet (ACT  103 ). Specifically, the sheet to which the RFID tag is attached is supplied from the sheet accommodation unit  140  in accordance with the reception of the printing job. The printer unit  130  develops the image on the basis of the acquired image information. The printer unit  130  forms an image by fixing the image developed on the supplied sheet. 
     The antenna  154  writes the write information on the RFID tag (ACT  104 ). Specifically, when the sheet having the image formed thereon is conveyed, the antenna  154  emits electromagnetic waves for writing write information. The RFID tag attached to the sheet receives the electromagnetic waves, and thus the write information is written in a storage area of the RFID tag. The antenna  154  reads information previously written to the RFID tag (ACT  105 ). Specifically, an interrogation signal. the electromagnetic waves used for reading the information from the RFID tag, is emitted. The RFID tag attached to the sheet receives the interrogation signal, and the information recorded in the storage area of the RFID tag is transmitted to the antenna  154 . The antenna  154  outputs the information received from the RFID tag to the processor  153  as read information. 
     The processor  153  determines whether or not writing to the RFID tag has been properly performed (ACT  106 ). Specifically, the processor  153  determines whether the read information satisfies a predetermined condition related to the correctness of information. For example, if the write information acquired from the write information server  300  and the read information read from the RFID tag are consistent with each other, the processor  153  determines that the writing has been properly performed on the RFID tag. If the write information acquired from the write information server  300  and the read information read from the RFID tag are inconsistent, it is determined that the writing has not been properly performed on the RFID tag. 
     If the writing has been properly performed on the RFID tag (ACT  106 : YES), the printer unit  130  forms an image on the rear surface of the sheet on the basis of the image information acquired from the write information server  300  (ACT  107 ). Specifically, the processor  153  performs control so that an image based on the image information acquired in accordance with the printing job received by the image forming apparatus  100  is formed on the other surface of the sheet on which an image is formed in ACT  103 . The printer unit  130  forms an image on the rear surface of the sheet. 
     If a predetermined condition related to an RFID tag is not satisfied (ACT  106 : NO), the printer unit  130  forms a void image on the rear surface of the sheet (ACT  108 ). Specifically, the processor  153  controls the printer unit  130  so that a developer to be used to form an image on the rear surface of the sheet is removed from the developer carrier. The processor  153  controls the printer unit  130  so that a void image is formed. The printer unit  130  forms a void image on the rear surface of the sheet. The image forming apparatus  100  discharges the sheet (ACT  109 ). 
     In the above-described embodiment, a case where both-side printing is performed is described, but the embodiment is not limited to a case where both-side printing is performed. For example, the image forming apparatus  100  may be configured such that a void image is formed when single-side printing of a plurality of sheets is performed. Specifically, if the writing on an RFID tag has not been properly performed, the processor  153  causes a sheet from the sheet discharging unit  156  to be conveyed along the sheet reversing path  157 . Next, the sheet conveyed to the sheet reversing path  157  is temporarily stopped by the registration unit  158 . The printer unit  130  removes a developer to be used to form an image on the next sheet from the developer carrier. The processor  153  controls the printer unit  130  so that a void image is formed. The printer unit  130  forms a void image on the rear surface of the sheet conveyed from the sheet reversing path  157 . The image forming apparatus  100  discharges the sheet. 
     The antenna  154  of the image forming apparatus  100  configured in this manner reads information written on an RFID tag attached to a conveyed sheet. The printer unit  130  of the image forming apparatus  100  forms at least one of an image designated by the received printing job and an image indicating a writing error on a sheet. If the read information satisfies a predetermined condition related to correctness of information, the control unit (for example, the processor  153 ) of the image forming apparatus  100  controls the printer unit  130  so that an image designated by the printing job is formed on a sheet or a next sheet to be conveyed subsequently to the sheet. If the read information does not satisfy the predetermined condition related to correctness of information, the control unit controls the printer unit  130  so that a developer carried on the developer carrier is removed from the developer carrier in accordance with the printing job. Next, the control unit controls the printer unit  130  so that an image indicating the writing error is formed on a sheet. 
     For this reason, the image forming apparatus can print a void image on a sheet even when writing on an RFID tag is not successful at the time of performing both-side printing. With such a configuration, the image forming apparatus  100  can form an image indicating that writing on an RFID tag is not successful even when an image is continuously formed on a plurality of sheets or an image is formed on both sides of a sheet. 
     Second Embodiment 
     Next, an image forming apparatus  100   a  in a second embodiment will be described. The image forming apparatus  100   a  in the second embodiment differs from the first embodiment in terms of a location at which antenna  154  is provided, but the other configurations are otherwise the same. Hereinafter, differences from the first embodiment will be described. 
       FIG. 9  is a diagram illustrating a specific example of an internal configuration of the image forming apparatus  100   a  according to the second embodiment. The image forming apparatus  100   a  differs from the first embodiment in that the antenna  154  is provided upstream of the printer unit  130 , but the other configurations are the same. With such a configuration, if it is determined that information written to an RFID tag is not normal, the processor  153  controls the printer unit  130  so that a developer to be used to form an image on a front surface of a sheet is removed from a developer carrier. Next, the processor  153  controls the printer unit  130  so that a void image is formed. The printer unit  130  forms a void image on a front surface of a sheet. With such a configuration, the image forming apparatus  100   a  can print the void image without forming an image on the basis of image information when it is determined that the information written to the RFID tag is not normal. Further, if it is determined that the information written to the RFID tag is not normal, the image forming apparatus  100   a  may be configured to discharge a sheet without forming an image on a sheet. With such a configuration, the image forming apparatus  100   a  can save a developer used to form a void image. 
     MODIFICATION EXAMPLE 
     The image forming apparatus  100  may be configured such that a void image is formed on a rear end side of a sheet to be conveyed. With such a configuration, the image forming apparatus  100  can reduce a period of time for which a sheet is temporarily stopped by the registration unit  158  by a conveyance time for a front end portion of a sheet. 
     If information written on an RFID tag does not satisfy a predetermined condition related to the RFID tag, the image forming apparatus  100  may be configured such that an image is formed on a sheet to be conveyed next on the basis of a printing job executed during image formation on a sheet. Specifically, if the writing of information to the RFID tag has not been properly performed, the processor  153  records write information acquired from the write information server  300  and image information associated with the write information in the storage device  151  or the memory  152 . Next, the processor  153  performs control so that a sheet having a void image formed thereon is discharged. The processor  153  controls the printer unit  130  so that an image is formed on a sheet to be conveyed next on the basis of the image information recorded in the storage device  151  or the memory  152 . The processor  153  controls the antenna  154  so that write information recorded in the storage device  151  or the memory  152  is written to an RFID tag attached to a sheet having an image formed thereon. With such a configuration, the image forming apparatus  100  can form an image without receiving the printing job again even when the information written to the RFID tag does not satisfy a predetermined condition related to the RFID tag. 
     The image forming apparatus  100  may be configured so as to form a void image using a developer provided on the most downstream side of the printer unit  130 . That is, in the image forming apparatus  100  of the present embodiment, a black developer is used. With such a configuration, the distance at which a developed image is conveyed to a position where the image is transferred to the sheet through a transfer belt is shorter than that when different developer is used, and thus the image forming apparatus  100  can reduce the period of time for which a sheet is delayed by the registration unit  158  by the conveyance time for a developer in the printer unit  130 . 
     According to present disclosure, at least one embodiment provides an image forming apparatus and an image forming method which are capable of performing printing indicating that writing to an RFID tag was not successful even when images are being continuously printed on a plurality of sheets and/or both-side printing is performed on sheets, by incorporating and utilizing a printer unit  130 , a processor  153 , and an antenna  154 . 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.