Image forming system, inspection device, and inspection method

An image processing system includes an image forming device, a sensor, processing circuitry, and an ejection device. The image forming device forms an image based on print information, on a first conveyance medium. The sensor acquires information about the image formed on the first conveyance medium. The processing circuitry causes a second conveyance medium to be ejected in a case where the image formed on the first conveyance medium is a defective image, based on the acquired information. The ejection device stacks the first conveyance medium and the second conveyance medium. The processing circuitry controls display of identification information that distinguishes and associates each one of a plurality of first conveyance media having defective images, with a corresponding one of a plurality of second conveyance media.

CROSS-REFERENCE TO RELATED APPLICATIONS

This patent application is based on and claims priority pursuant to 35 U.S.C. § 119(a) to Japanese Patent Application No. 2021-046488, filed on Mar. 19, 2021, in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein.

BACKGROUND

Technical Field

Embodiments of the present disclosure relate to an image forming system, an inspection device, and an inspection method.

Related Art

Various technologies have been developed that detect a defect in an image formed by the image forming apparatus, based on a result of reading the image. For example, a technology is known that inserts a slip sheet (insertion sheet) between a bundle of printed materials so that a printed material in which a defect is detected is easily found from the bundle of printed materials stacked on a sheet ejection tray.

SUMMARY

Embodiments of the present disclosure described herein provide a novel image processing system including an image forming device, a sensor, processing circuitry, an ejection device. The image forming device forms an image based on print information, on a first conveyance medium. The sensor acquires information about the image formed on the first conveyance medium by the image forming device. The processing circuitry causes a second conveyance medium to be ejected in a case where the image formed on the first conveyance medium is a defective image, based on the information acquired by the sensor. The ejection device stacks the first conveyance medium and the second conveyance medium. The processing circuitry controls display of identification information that distinguishes and associates each one of a plurality of first conveyance media having defective images stacked on the ejection device, with a corresponding one of a plurality of second conveyance media stacked on the ejection device.

DETAILED DESCRIPTION

First Embodiment

Descriptions are given of an image forming system according to a first embodiment of the present disclosure, with reference to the drawings.

FIG.1is a diagram illustrating an overall configuration of an image forming system, according to embodiments of the present disclosure.

An image forming system1includes an image forming apparatus10, a user terminal30, a management server40, and a digital front end (DFE)50.

The image forming apparatus10is an apparatus to form an image, and is, for example, a color production printer, a laser printer, or an inkjet printer. The image forming apparatus10receives image data from the DFE50and prints the image on a sheet based on the received image data. Note that the sheet is an example of a recording medium on which an image is formed.

The user terminal30is a terminal that receives an operation from a user and instructs to print the image. Specifically, the user terminal30transmits print job data including image data to the DFE50or the management server40. The user terminal30transmits information indicating a threshold in color stabilization processing to the DFE50in response to an operation of the user. In addition, the user terminal30receives display control by the DFE50and displays a screen indicating an execution status of the color stabilization processing.

The management server40adds the print job data as a queue to a memory that stores the print job data waiting for printing in response to the receipt of the print job data from the user terminal30. The management server40extracts print job data from the queue in the order in which the print job data is added to the queue or in accordance with a priority set appropriately. Then, the management server40transmits the print job data to the DFE50.

The DFE50is an apparatus that controls the image forming apparatus10, for example, a DFE. The DFE50is communicably connected to the image forming apparatus10, the user terminal30, and the management server40.

When the DFE50receives print job data with a signal that instructs to print the image from the user terminal30or the management server40, the DFE50converts the print job data into image data in a format that is processed by the image forming apparatus10, using a raster image processor (RIP) engine included in the image forming apparatus10. Then, the DFE50transmits the converted image data to the image forming apparatus10.

FIG.2is a diagram illustrating a hardware configuration of an image forming apparatus of the image forming system ofFIG.1.

The image forming apparatus10includes a printer11, an inspection device13, and a stacker14.

The printer11receives the print job data including a print image (rasterized image) from an external apparatus such as the DFE50. Then, the printer11executes printing in response to an execution instruction based on the received print job data or an execution instruction based on the print job data stored in the printer11by a user's operation on an operation panel12.

The printer11has a configuration in which photoconductor drums116,115,114, and113are disposed along an intermediate transfer belt111. The photoconductor drums116,115,114, and113form yellow (Y), magenta (M), cyan (C), and black (K) toner images, respectively. The intermediate transfer belt111is a moving unit of an endless loop. Images of the respective colors are developed with toner on the respective surfaces of the photoconductor drums116,115,114, and113and are transferred and superimposed one after another onto the surface of the intermediate transfer belt111to form a full-color image.

The full-color image borne on the intermediate transfer belt111is transferred onto the sheet by a transfer roller112. The sheet is fed from a sheet feeding tray105and conveyed by a transfer roller112. Then, the sheet is further conveyed, and the toner is fixed to the sheet by a fixing roller117. Note that, when outputting a slip sheet without printing, another sheet feeding tray for the slip sheet may be provided separate from the sheet feeding tray105. Further, a slip sheet feeding device may be provided in the inspection device13or between the printer11and the inspection device13.

In the case of duplex printing, after the image is formed on the front side, the sheet is conveyed to a sheet reverse passage118in the sheet conveyance passage, then is reversed, and is conveyed again to the position of the transfer roller112.

The inspection device13is a device that inspects printed sheets by the printer11. Each of the printed sheets to be inspected is referred to as a first conveyance medium in the present disclosure. The inspection device13includes a first inline sensor131, a second inline sensor132, and an operation panel133. The inspection device13may not include the operation panel133. In this case, the inspection device13may be configured to receive an operation through the operation panel12of the printer11or a computer connected via a communication network.

The first inline sensor131and the second inline sensor132read the images fixed on both sides of the sheet by the fixing roller117and obtain read image data indicating the read images. The number of inline sensors is not limited to two and may be one or three or more as long as both sides of the sheet are read. An inline sensor includes a light source and a line image sensor. The light source irradiate light onto a sheet passing over a reading position. The line image sensor includes a plurality of imaging elements aligned one dimensionally in the width direction of a sheet. The plurality of imaging elements optically converts reflected light reflected on the sheet for each pixel to read the reflected light. The inline sensor reads an image printed on the sheet as a two-dimensional image by repeatedly performing an operation of reading the image for one line in the width direction of the sheet, in accordance with the sheet passing operation over the reading position. Further, the line image sensor captures read images of three colors of red, green, and blue (RGB). The inline sensor is an example of an information acquisition device that acquires information about the image on the sheet. The information acquisition device may acquire information other than the read image data as long as the information is information for detecting a defect such as image data or bibliographic information of the image data.

The stacker14includes a sheet ejection tray141and stacks printed sheets ejected from the printer11via the inspection device13on the sheet ejection tray141. The stacker14and the sheet ejection tray141are configured to receive and stack the printed sheets and the slip sheets. The stacker14and the sheet ejection tray141are an example of an ejection device in the present disclosure. The stacker14may have a plurality of sheet ejection trays141.

The present embodiment is given providing that, for example, that the rasterized image is in the CMYK format (format in a subtractive color mode including cyan, magenta, yellow, and black) with 8 bits colors and 600 dpi resolution, and the read image is in the RGB format with 8 bits colors and 200 dpi resolution. However, embodiments of the present disclosure are not limited to the above-described data formats in image formation.

FIG.3is a diagram illustrating a hardware configuration of a printer of the image forming system ofFIG.1.

The printer11includes a controller1110, a short-range communication circuit1120, an engine controller1130, the operation panel12, and a network I/F1150.

The controller1110includes a central processing unit (CPU)1101that is a main part of a computer, a system memory (MEM-P)1102, a north bridge (NB)1103, a south bridge (SB)1104, an application specific integrated circuit (ASIC)1106, a local memory (MEM-C)1107that is a memory, a hard disk drive (HDD) controller1108, and a hard disk (HD)1109that is a memory.

The NB1103and the ASIC1106are connected by an accelerated graphics port (AGP) bus1121.

The CPU1101is a control device that performs overall control of the printer11. The NB1103is a bridge configured to connect the CPU1101, the MEM-P1102, the SB1104, and the AGP bus1121. The NB1103includes a memory controller that controls reading from and writing to the MEM-P1102, a peripheral component interconnect (PCI) master, and an AGP target.

The MEM-P1102includes a read only memory (ROM)1102aand a random access memory (RAM)1102b. The ROM1102ais a memory to store programs and data for implementing various functions of the controller1110. The RAM1102bis a memory configured to deploy programs, data or to render print data for memory printing. The program stored in the RAM1102bmay be provided as a file in an installable format or an executable format that the program is recorded in a computer-readable storage medium such as a compact disc-read only memory (CD-ROM), a compact disc-recordable (CD-R), or a digital versatile disc (DVD).

The SB1104is a bridge configured to connect the NB1103to PCI devices and peripheral devices. The ASIC1106is an integrated circuit (IC) for image processing having a hardware element for image processing and has a role of a bridge that connects the AGP bus1121, the PCI bus1122, the HDD controller1108, and the MEM-C1107to each other.

The ASIC1106includes a PCI target, an AGP master, an arbiter (ARB) serving as a core of the ASIC1106, a memory controller that controls the MEM-C1107, a plurality of direct memory access controllers (DMAC) that rotates image data by hardware logic, and a PCI unit that transfers data between a scanner section1131and a printer section1132via the PCI bus1122. A universal serial bus (USB) interface or an Institute of Electrical and Electronics Engineers1394(IEEE 1394) interface may be connected to the ASIC1106.

The MEM-C1107is a local memory used as a copy image buffer and a code buffer. The HD1109is a memory that stores image data, font data used in printing, and forms. The HD1109controls reading or writing of data from or to the HD1109under the control of the CPU1101.

The AGP bus1121is a bus interface for a graphics accelerator card that has been proposed to speed up graphics processing. The AGP bus1121is a bus that directly access the MEM-P1102at high throughput to speed up a graphics accelerator card.

The short-range communication circuit1120includes a short-range communication antenna1120a. The short-range communication circuit1120is a communication circuit that communicates in compliance with the near field radio communication (NFC) or the Bluetooth®.

The engine controller1130includes the scanner section1131and the printer section1132. The operation panel12includes a panel display12aand a hard keys12b. The panel display12ais, e.g., a touch panel that displays current settings or a selection screen that receives the user input. The hard keys12bincludes, e.g., a numeric keypad and a start key. The numeric keypad receives setting values of image forming parameters such as an image density parameter. The start key receives an instruction to start copying.

The controller1110controls the overall printer11and controls, for example, drawing, communication, and input from the operation panel12. The scanner section1131reads the image formed on a conveyance medium such as a sheet and generates image data. The printer section1132includes a transfer device that transfers the image using a color material such as a toner image onto a conveyance medium such as the sheet, a fixing device that fixes the image, a heating device, a drying device, and performs image formation on the sheet. Further, the scanner section1131or the printer section1132executes image processing such as error diffusion and gamma conversion.

The network I/F1150is an interface that performs communication of data through the communication network. The short-range communication circuit1120and the network I/F1150are electrically connected to the ASIC1106via the PCI bus1122.

FIG.4is a diagram illustrating a hardware configuration of an inspection device of the image forming apparatus ofFIG.2.

The inspection device13includes the first inline sensor131, the second inline sensor132, the operation panel133, and a CPU134, a ROM135, a RAM136, an HDD/solid state drive (SSD)137, a network I/F138, and an external I/F139. The CPU134, the ROM135, the RAM136, and the HDD/SSD are configured by a computer.

The CPU134reads programs stored in the ROM135or the HDD/SSD137and stores the programs in the RAM136. Then, the CPU134executes various processes in accordance with the program stored in the RAM136. The processes are described below.

The ROM135is a non-volatility auxiliary memory device. The ROM135stores programs such as a basic input/output system (BIOS) that is programed basic operations of the inspection device13.

The RAM136is a volatile main memory device. The RAM136is used as a working area of the CPU134.

The HDD/SSD137is a large capacity non-volatility auxiliary memory device. The HDD/SSD137stores received image data, programs for various processes, and setting information. The processes are described below.

The network I/F138is, for example, a local area network (LAN) card, and is a relay unit for communicating with other devices via a communication network.

The external I/F139is a relay unit for communicating with the devices connected as external devices, such as the DFE50, the printer11, and the stacker14.

Note that the DFE50has the substantially same hardware configuration as the hardware configuration of the inspection device13, except that the DFE50has the first inline sensor131, the second inline sensor132, and the operation panel133.

FIG.5is a diagram illustrating functions of the DFE of the image forming system ofFIG.1.

The DFE50includes a system control unit501, a print job receiving unit502, a storage unit503, a print job transmission unit504, and a display control unit505. Each of the units of the DFE50is achieved by a CPU included in the DFE50executing processing defined in programs stored in a ROM included in the DFE50.

The system control unit501includes a job information processing unit551, a rasterized image processing unit552, a control information storage unit553, and a gradation correcting unit554.

The job information processing unit551processes information about a job included in the print job data.

The rasterized image processing unit552performs predetermined color conversion processing on the CMYK values or the RGB values of the input image data using a RIP engine and converts the CMYK values or the RGB values into image data in a CMYK format suitable for the image forming apparatus10.

The control information storage unit553stores control information controlled by the system control unit501.

The gradation correcting unit554corrects gradation of the image data converted by the rasterized image processing unit552.

The print job receiving unit502receives the print job data from the user terminal30or the management server40via the communication network60.

The storage unit503stores the received print job data.

The print job transmission unit504transmits the print job data to the image forming apparatus10. The print job data is generated through processing by the system control unit501. The print job data transmitted to the image forming apparatus10includes rasterized image data and job information indicating attributes of the print job.

The display control unit505controls to display information generated by the system control unit501on the display device51.

FIG.6is a diagram illustrating functions of the printer of the image forming apparatus ofFIG.2.

The printer11includes a system control unit201, a display control unit202, a network I/F control unit203, an external I/F control unit204, a storage unit205, a mechanism control unit206, a print job receiving unit207, an image processing control unit208, and a printing control unit209. Each of these units of the printer11is achieved by the CPU1101or the ASIC1106of the printer11executing process defined in programs stored in the MEM-P1102or the MEM-C1107.

The system control unit201controls the overall operation of the printer11. The system control unit201includes a job information processing unit211, a rasterized image processing unit212, and a job information generation unit213.

The job information processing unit211processes job information included in the print job transmitted from the DFE50. The rasterized image processing unit212processes the rasterized image data included in the print job transmitted from the DFE50. The job information generation unit213generates job information for printing the slip sheet in response to receipt of information to be printed on the slip sheet (slip sheet print information) from the inspection device13. The format of an image to be printed on the slip sheet is determined in advance so as to be determined based on the slip sheet print information. Then, the storage unit205stores information indicating a format for printing on the slip sheet. The format may be determined for each type or size of the sheets. Further, the format may be stored in the storage unit205in advance or may be transmitted together with a first slip print information by the inspection device13.

Note that the slip sheet (insertion sheet) may be a sheet such as cut paper that is a conveyable medium by the printer11. The conveyance medium may be a colored sheet, a blank sheet, or a blank sheet having a size different from the size of the sheet of the print job, a film sheet, a plastic sheet, as long as the conveyance medium has identification information of the slip sheet (conveyance medium) and is stacked in a sheet feeding tray provided for the printer11, to be conveyed and output according to an output instruction of the slip sheet. The slip sheet is referred to as a second conveyance medium while a printed sheet is referred to as a first conveyance medium as described above. The identification information of the slip sheet (second conveyance medium) is printed by an image forming unit of the printer11. Alternatively, the identification information may be applied to or printed on the slip sheet in advance, or the size or ejection direction of the sheet may be used as the identification information of the slip sheet (second conveyance medium). The identification information of the slip sheet (second conveyance medium) is an example of “identification information that distinguishes and associates each of the plurality of first conveyance media having defective images stacked on the ejection device, with a corresponding one of the plurality of second conveyance media stacked on the ejection device”. In other words, the identification information of the slip sheet (second conveyance medium) is information indicating that the image is formed on each of the plurality of second conveyance media, and each of the plurality of second conveyance media corresponds to each of the plurality of first conveyance media having defects. The image forming unit of the printer11controls the printer section1132to form an image including the identification information of the second conveyance medium on the second conveyance medium. Accordingly, even when a plurality of defective printed sheets and the plurality of slip sheets corresponding to the defective printed sheets are ejected to an ejection device such as a sheet ejection tray, it is easy for a user to distinguish the slip sheets and confirm the defective printed sheets corresponding to each of the slip sheets.

The display control unit202controls to display various types of information including job information on the operation panel12. The network I/F control unit203controls the network I/F1150and performs connection control with a communication network. When another device is connected to the printer11, the external I/F control unit204performs connection control with the connected device. The storage unit205stores various types of information including job information.

The mechanism control unit206controls operations of mechanisms included in the printer11, such as operations of a mechanism that performs sheet conveyance and operations of a mechanism that performs transfer process in the printer11including the printer section1132. The print job receiving unit207receives the print job from the DFE50. The image processing control unit208processes the print image transferred by the mechanism control unit206. The printing control unit209controls image formation on the conveyance medium. The mechanism control unit206, the image processing control unit208, and the printing control unit209cooperate with each other to function as the image forming unit that forms an image on the conveyance medium. Further, the information acquisition device such as the inline sensor may acquire information on an image based on the image after toner is fixed to the conveyance medium by the fixing roller117or based on the image before the conveyance medium enters the fixing roller117after the image is transferred by the transfer roller112.

FIG.7is a diagram illustrating functions of the inspection device of the image forming apparatus ofFIG.2.

The inspection device13includes a system control unit301, a display control unit302, a network I/F control unit303, an external I/F control unit304, a storage unit305, a mechanism control unit306, a print image reading unit307, a master image generation unit308, and a difference image generation unit309. Each of these units is achieved by the CPU134or the ASIC1106of the inspection device13executing processing defined in programs stored in the MEM-P1102or the MEM-C1107of the inspection device13.

The system control unit301controls the overall operation of inspection device13. The system control unit301includes a control information storage unit311, a job information processing unit312, a defect determination unit313, an ejection control unit314, and an ejection setting unit315.

The control information storage unit311stores control information controlled by the system control unit301. Further, the control information storage unit311temporarily stores received job information while the job information is an object to be controlled.

The job information processing unit312extracts information to be processed by a post-processing device (for example, a device that performs post-processing such as the stacker14) from job information and transmits the extracted information to the post-processing device via the external I/F control unit304. Further, the job information processing unit312transfers job information excluding information to be processed by the post-processing device, to the master image generation unit308, the defect determination unit313, the print image reading unit307, and the mechanism control unit306.

The display control unit302controls to display various types of information including an inspection result on the operation panel133or a different device. The different device includes a terminal device used by a user, such as a personal computer (PC) or a tablet PC, the DFE50, the printer11. The display control unit302performs process of returning information stored in the inspection device13in response to a request from software such as a web browser executing in the different device. Further, the display control unit302and software executing in the different device transmit information of the inspection device13to the different device using a bidirectional communication protocol such as WebSocket and display the information in real time. For example, when software executing in the different device displays a list of defective printed sheets by accessing the inspection device13, the list is automatically updated each time a defect occurs, and information of a defective printed sheet or information of the slip sheets is additionally displayed. The display control unit302may be included in the inspection device13as a web server or may be included in a cloud server that receives information of the inspection result from the inspection device13. The operation panel133, a display of the different device, and software such as the web browser are examples of a display unit on which the display control unit302of the present disclosure displays information.

The network I/F control unit303controls the network I/F138. The external I/F control unit304controls the external I/F139.

The storage unit305stores various types of information. Specifically, job execution history information related to the print job that the control has been ended, and a difference image data indicating the difference between the read image data and the master image data are stored.

The mechanism control unit306controls an operation of a mechanism included in the inspection device13such as conveyance of the sheet.

The print image reading unit307controls the first inline sensor131and the second inline sensor132to read the image formed on a sheet by the printer11, and to generate read image data indicating the read image.

The master image generation unit308generates master image data based on the rasterized image data. Specifically, the master image generation unit308converts rasterized image data in the CMYK format into master image data in the RGB format.

Note that the master image data is data serving as a reference for comparison with the read image data and is used as the correct data when printed correctly. The master image data may be created by reading the sheet on which a reference image is printed with the scanner section1131, the inline sensor, or a scanner of an external device.

The difference image generation unit309generates difference image data indicating a difference between the master image data and the read image data.

The defect determination unit313determines whether the printed image has a defect by comparing the difference image data with a predetermined threshold. The threshold is information (value) serving as a criterion for determining that the image has the defect. The defect determination unit313refers to the threshold and determines that the image has the defect if the difference image data has an area exceeding the threshold. The threshold is, for example, a value indicating that a difference (comparison result) between density values of each pixel included in the difference image data is equal to or greater than a predetermined density value, or a value indicating an area of a portion where pixels having a difference equal to or greater than the predetermined density value are continuous. The setting of the threshold is changed by the user so that the threshold is increased (the criterion is relaxed) or decreased (the criterion is tightened). A defect refers to a portion of image data determined to be different from an image desired by the user (for example, master image data) when a determination result determined by the defect determination unit313exceeds a threshold. The defect includes, for example, a spot, a streak, a positional deviation of the image, a difference in color, and a void in color.

Note that the defect determination method may be a determination method of determining whether the value of a printed image exceeds a set threshold (difference from ideal image data) based on a read image data obtained by reading ideal image data in advance of printing, other than the above-described method of comparing master image data and read image data. Further, before the defect determination processing is performed, correction processing may be performed to increase the accuracy of the determination processing. The correction processing is processing such as skew correction of read image data for correcting read image data of a medium conveyed in a skewed manner to a correct orientation or position, or flare correction for correcting a white light portion in read image data at the time of reading.

When the defect determination unit313determines that the image has a defect, the ejection control unit314controls to eject the slip sheet (second conveyance medium) indicating that the image has the defect. The slip sheet is a sheet to be inserted between specified sheets of a bundle of printed sheets stacked on the stacker14and the slip sheet has an outstanding color tone as described below.

Specifically, when the defect determination unit313determines that the image has the defect, the ejection control unit314determines whether to insert the slip sheet based on a threshold of an insertion interval set in advance. The threshold of the insertion interval is received by the ejection setting unit315. When the defect determination unit313determines that the slip sheet is inserted, information for printing the slip sheet (slip sheet printing information) is generated and transmitted to the printer11. As a result, the ejection control unit314instructs the image forming unit of the printer11to print the image to be printed on the slip sheet. Note that the ejection control unit314may instruct the printer11to feed a predetermined slip sheet from the sheet feeding tray provided in the printer11and eject the slip sheet without printing. The predetermined slip sheet includes, for example, a colored sheet or a sheet having a size different from the size of a sheet used in a print job.

The ejection setting unit315receives a setting of an interval for the ejection control of the slip sheet. Specifically, the ejection setting unit315receives an input of the above-described threshold. A specific example of a screen for receiving settings is described below.

Descriptions are given of information that the image forming system1controls.

FIG.8is a diagram for explaining items of job information, according to embodiments of the present disclosure.

The job information901is bibliographic information included in print job data generated by the DFE50or the printer11. The job information901includes items “JOB GENERATION SOURCE”, “GENERATION TIME”, “PAGE ID”, “PRINT FACE”, “SHEET ID”, “COPY ID”, “JOB ID”, “SHEET TYPE”, “SHEET SIZE”, “JOB TYPE”, and “SLIP SHEET ID”. The job information901is an example of print information for performing printing.

The value of the item “JOB GENERATION SOURCE” is a value indicating the generation source of the print job data and is either a “DFE JOB” or an “INTERNAL JOB”. When the job information is included in the print job data to be transmitted to the image forming apparatus10by the DFE50, the value of the item “JOB GENERATION SOURCE” is the “DFE JOB”. When the job information generation unit213of the printer11generates the print job data for the slip sheet, since the print job data is generated inside the image forming apparatus10, the value of the item “JOB GENERATION SOURCE” is the “INTERNAL JOB”.

The value of the item “GENERATION TIME” is a value indicating the time at which the generation source generated the job information.

The value of the item “PAGE ID” is a numerical value to identify the print image and is incremented by one for output of each page starting from activation of the power source. The numerical value is set in the item “PAGE ID” when printing is executed.

The value of the item “PRINT FACE” is a value to identify whether the print image is to be printed on one side in single-sided printing, on the front face in duplex printing (front in duplex), or on the back face in duplex printing (back in duplex).

The value of the item “SHEET ID” is a numerical value to identify a sheet. When the duplex printing is performed, two “PAGE IDs” are given to the same sheet ID. The value of the item “SHEET ID” is incremented by one for process of each page starting from activation of the power source. A numerical value is set in the item “SHEET ID” when printing is executed.

The value of the item “COPY ID” is a numerical value to identify a unit of copy and is incremented by one for output of each copy starting from activation of the power source. A numerical value is set in the item “COPY ID” when printing is executed.

The value of the item “JOB ID” is a numerical value to identify the print job unit and is incremented by one for output of each job starting from activation of the power source. A numerical value is set in the item “JOB ID” when printing is executed.

The value of the item “SHEET TYPE” is a value indicating the type of sheets. The value of the item “SHEET SIZE” is a value indicating the size of the sheets. Note that a sheet to be printed and used as a slip sheet is selectable, depending on the settings, between a sheet used in the print job in which the defect was detected or a sheet stacked on a designated sheet feeding tray. By using a sheet used in the print job for printing an image on the slip sheet, time-consuming process such as readjustment of the fixing temperature does not need to be performed, and the processing time is shortened. Further, when a sheet to be printed and used as a slip sheet is a sheet stacked on the designated sheet feeding tray, an inexpensive sheet is used to be dedicated to the slip sheet, and the cost is reduced.

The value of the item “JOB TYPE” is a value indicating whether the job is a target of defect detection, a non-target of defect detection, or a slip sheet for defect detection identification. When the job information generation unit213of the printer11generates the print job data for slip sheets, the value of the item “JOB TYPE” is a value indicating a slip sheet for defect detection identification. When the value of the item “JOB TYPE” is a value indicating a non-target of defect detection or a slip sheet for defect detection identification, the defect determination unit313does not execute processing.

The value of the item “SLIP SHEET ID” is an identifier to identify the slip sheet. The value of the item “SLIP SHEET ID” is notified from the inspection device13to the printer11. In a case of a job generated by the DFE50or a job generated by the printer11for other than a slip sheet, a slip sheet ID does not exist. For this reason, the value “−1” is set in the item “SLIP SHEET ID” as a value indicating that a slip sheet ID does not exist.

FIG.9is a diagram illustrating pattern information, according to embodiments of the present disclosure.

The pattern information902is set in advance and stored in the storage unit305or in the control information storage unit311of the inspection device13. The ejection control unit314determines a color pattern to be printed on the slip sheet with reference to the pattern information902. The pattern information902includes items “PATTERN NUMBER” and “CONTENTS”.

The value of the item “PATTERN NUMBER” is a value indicating the number of each pattern of the pattern information902. The value of the item “CONTENTS” is a value indicating a combination of colors in each pattern of the pattern information902.

The control information storage unit311stores a pattern number indicating which pattern of the pattern information902is referred to by the ejection control unit314. The initial value of the pattern number is zero when the power source is turned on. The ejection control unit314increments by one to a numerical value indicating the pattern number stored in the control information storage unit311each time a print job for a slip sheet is generated with reference to the pattern information902. The numerical value is reset to zero when the numerical value exceeds the maximum value.

The pattern information902may be changed by the user. For example, the pattern information902may allow the user to change the maximum value of the pattern (for example, 6 patterns inFIG.9) or the combination of colors corresponding to the pattern number.

FIG.10is a first diagram illustrating the slip sheet print information, according to embodiments of the present disclosure.

The slip sheet print information903is information indicating a combination of colors to be printed on each slip sheet and includes “SLIP SHEET ID” and “CONTENTS” as items.

The value of the item “SLIP SHEET ID” is an identifier to identify the slip sheet.

The value of the item “CONTENTS” is a value indicating a combination of colors to be printed for each slip sheet.

The slip sheet print information903is information generated by the ejection control unit314with reference to the pattern information902. The ejection control unit314increments a numerical value indicating the slip sheet ID by one.

Next, descriptions are given of operations of the image forming system1.

FIG.11is a sequence diagram illustrating a flow of print processing without the slip sheet, according to embodiments of the present disclosure.

When the print job receiving unit502of the DFE50receives print job data from the user terminal30or the management server40, the job information processing unit551generates job information (bibliographic information about the print job) for each page of the print job. Then, in step S101, the print job transmission unit504of the DFE50transmits job information (for example, page n) to the printer11.

In step S102, when the print job receiving unit207of the printer11receives the job information (page n), the job information processing unit211of the printer11performs processing such as addition of the numerical value indicating the page ID to update the received job information (page n) and transmits the updated job information to the inspection device13via the external I/F control unit204.

When the print job receiving unit502of the DFE50receives the print job from the user terminal30or the management server40, the rasterized image processing unit552of the DFE50performs processing of converting each page into the rasterized image data. The job information processing unit551and the rasterized image processing unit552of the DFE50perform processing in parallel, and the job information that completes processing first is transmitted to the printer11first. For example, the DFE50generates and transmits job information for page n+1 and page n+2 before starting transmission of the rasterized image data (page n). Then, in steps S103to S106, the printer11updates the received job information and transmits the updated job information to the inspection device13.

Then, the rasterized image processing unit552of the DFE50generates rasterized image data (page n) corresponding to the job information (page n). In step S107, the print job transmission unit504transmits the rasterized image (page n) to the printer11. In step S108, the rasterized image processing unit212of the printer11performs processing for the rasterized image data and transmits the processed rasterized image data to the inspection device13.

The master image generation unit308of the inspection device13generates master image data (page n) according to the job information (page n) and the rasterized image data (page n). Then, in accordance with the job information, the inspection device13associates the order of pages detected by the first inline sensor131and the second inline sensor132with the generated master image data and stores the association result in the storage unit305.

In step S109, the image processing control unit208, the printing control unit209, and the mechanism control unit206of the printer11execute print processing in accordance with the job information (page n). The printed sheet (page n) is conveyed to the inspection device13.

In steps S110to S115, the DFE50and the printer11perform processing on the rasterized image (pages n+1 and n+2) in the same way. Then, in steps S116to S118, the print image reading unit307of the inspection device13acquires read image data (pages n, n+1, n+2) read by the first inline sensor131and the second inline sensor132.

Subsequently, the difference image generation unit309of the inspection device13generates difference image data indicating a difference between the master image data and the read image data for each page. The defect determination unit313determines whether the image includes any defect based on the generated difference image data and generates defect determination information. Then, the ejection control unit314executes inspection processing including an inspection of whether to eject the slip sheet (second conveyance medium). Details of the inspection processing are described below.

FIG.12is a sequence diagram illustrating a flow of the print processing with the slip sheet, according to embodiments of the present disclosure.

In the print processing with slip sheet illustrated inFIG.12, step S201and step S202are the same as step S101and step S102, respectively, of the print processing without slip sheet illustrated inFIG.11.

In the case the print processing with slip sheet, for example, in step S203, the defect determination unit313determines that the image includes a defect for the page n−5 on which print output has already been performed, and the ejection control unit314determines that the slip sheet is to be inserted by the inspection processing described below.

The ejection control unit314of the inspection device13replaces the “sheet count value of the previously inserted slip sheet” stored in the control information storage unit311with the “sheet count value” of the sheet currently determined that the sheet has a defect. The “sheet count value of the previously inserted slip sheet” is the number of pages serving as a reference for determining whether the slip sheet is inserted. In step S204, the inspection device13transmits the slip sheet print information903(page m) to the printer11.

Based on the received slip sheet print information903(page m), the job information generation unit213of the printer11determines the timing of inserting the slip sheet and generates job information (page m). For example, the timing of inserting the slip sheet may be a timing at which the slip sheet is inserted between page n and page n+1. Then, in step S205, the printer11transmits the generated job information (page m) to the inspection device13.

Step S206and step S207illustrated inFIG.12are the same as step S103and step S104, respectively, of the print processing without slip sheet illustrated inFIG.11.

Further, steps S208to S210illustrated inFIG.12are the same as steps S107to S109of the print processing without a slip sheet as illustrated inFIG.11.

In step S211, at the timing of inserting a slip sheet (for example, between page n and page n+1), the image processing control unit208, the printing control unit209, and the mechanism control unit206of the printer11execute the print processing (printing of a slip sheet) according to the job information (page m). Note that in the present embodiment, since the slip sheet print job is not a job generated in the DFE50, the rasterized image data of the slip sheet is not transmitted from the DFE50to the printer11. In step S204, the slip sheet print information903for slip sheet printing has already been sent from the inspection device13to the printer11. Note that the slip sheet print information903may be configured to be transmitted from the inspection device13to the printer11via the DFE50.

Steps S212to S214and step S215illustrated inFIG.12are the same as steps S110to S112and step S116, respectively, of the print processing without a slip sheet illustrated inFIG.11.

In step S216, the print image reading unit307of the inspection device13acquires the read image data (page m) read by the first inline sensor131and the second inline sensor132. In the case of the print job for slip sheet, the master image generation unit308of the inspection device13does not generate the master image data. The inspection device13associates the order of pages detected by the first inline sensor131and the second inline sensor132with the generated master image data according to the job information of each page including the page m and stores the associated information in the storage unit305.

When the read image data is based on a slip sheet print job (page m), the inspection device13discards the read image data without performing the inspection processing.

FIG.13is a flowchart illustrating a flow of the inspection processing, according to embodiments of the present disclosure.

In step S301, when the inspection processing starts, the ejection control unit314acquires the defect determination information. The defect determination information is information generated by the defect determination unit313and includes the information of defect determination result per printed page, the sheet count value, and the minimum value of the slip sheet insertion interval.

The sheet count value is set to zero when the power of the image forming apparatus10is turned on. The sheet count value is incremented by one each time the print sheet is ejected to the stacker14. The minimum value of the slip sheet insertion interval is set in advance in response to an operation performed by a user on the operation panel133of the inspection device13.

In step S302, the ejection control unit314determines the presence or absence of the defect with reference to the defect determination result included in the defect determination information. When it is determined that there is no defect (NO in step S302), the ejection control unit314ends the inspection processing.

In step S303, when it is determined that there is a defect (YES in step S302), the ejection control unit314determines whether the slip sheet is inserted. Specifically, when the following Equation 1 is satisfied, the ejection control unit314determines that the slip sheet is allowed to be inserted.
The minimum value of the slip sheet insertion interval<Sheet count value−Sheet count value of the previously inserted slip sheet  Equation 1.

However, when the sheet count value of the previously inserted slip sheet is zero, the ejection control unit314determines that the slip sheet is allowed to be inserted regardless of whether Equation 1 is satisfied or not.

That is, when it is determined that there is a defect in the printed sheet, the ejection control unit314determines that the slip sheet is allowed to be inserted in the following two cases. The first case is when the sheet count value (the number of output pages of the defective sheet) of the current sheet determined to be defective is larger than the sheet count value of the slip sheet (the number of output pages of the slip sheet) at the previous insertion of the slip sheet and is greater than a predetermined insertion interval. The second case is when the slip sheet has not been inserted yet.

The determination method is not limited to the above-described method. The following method may be employed as an alternative method. When the ejection control unit314has determined that there is a defect in the image of the first conveyance medium, in a case where the ejection of the first conveyance medium determined to be defective is after the second conveyance medium is ejected and the value of the slip sheet insertion interval is equal to or smaller than the set interval, the second conveyance medium is not ejected even if the image of the first conveyance medium has a defect. On the other hand, when the value of the slip sheet insertion interval is greater than the set interval, the second conveyance medium is ejected when the ejection control unit314has determined that the first conveyance medium is defective. At this time, the display control unit302displays information of the defective first conveyance medium ejected after the second conveyance medium previously ejected, in association with information of the second conveyance medium to be currently ejected.

The sheet count value of the previously inserted slip sheet is stored in the control information storage unit311and is set to zero when the power of the image forming apparatus10is turned on.

When the ejection control unit314determines that the slip sheet is not allowed to be inserted (NO in step S303), the ejection control unit314ends the inspection processing. When it is determined that the slip sheet is inserted (YES in step S303), the ejection control unit314replaces the “sheet count value of the previously inserted slip sheet” stored in the control information storage unit311with the “sheet count value”, and transmits the slip sheet print information903, in step S304.

When the slip sheet is not allowed to be inserted, the ejection control unit314may wait until suitable timing for inserting the slip sheet and then insert the slip sheet again. That is, the timing at which the slip sheet is inserted is indicated by interrupting again the print job in which the slip sheet is not allowed to be inserted. Due to the above-described configuration, the slip sheet is allowed to be inserted each time the defect is found.

FIG.14is a diagram illustrating the slip sheet, according to embodiments of the present disclosure.

A slip sheet ID905is printed on the slip sheet904, for example, at two upper and lower positions. Images of colors specified in the pattern information902are alternately printed as pattern images906on the outer circumferential portion of the slip sheet904. The slip sheet ID and the pattern images906are an example of identification information to identify the slip sheet (second conveyance medium). Alternatively, the identification information may be a mark or a pattern.

FIG.15is a diagram illustrating a defect display screen, according to embodiments of the present disclosure. The display screen illustrated inFIG.15and the subsequent drawings are screens displayed on a display unit by the display control unit302transmitting screen information in response to a request received from the display unit such as an operation panel of an apparatus or a web browser of another apparatus. The display control unit302may display screen information on the display unit by bidirectional communication or push transmission.

A defect display screen907is a screen displayed on the operation panel133of the inspection device13in order to display the detected defects. The defect display screen907includes a “JOB LIST” display area908, a “DEFECT DETECTION PAGE LIST” display area909, and a “DEFECT DETECTION IMAGE” display area910.

FIG.16is a diagram illustrating a job list, according to embodiments of the present disclosure.

The job list displayed in the “JOB LIST” display area908includes items “INSPECTION PROCESSING START TIME”, “NUMBER OF COPIES OF JOB”, “NUMBER OF PAGES OF JOB”, and “NUMBER OF DEFECT-DETECTED PAGES OF JOB”. The job list may include identification information to identify the job, such as job names or job IDs, with which a plurality of jobs is confirmed and identified.

The value of the item “INSPECTION PROCESSING START TIME” is a value indicating the start time of the inspection processing of the first page of the print job.

The value of the item “NUMBER OF COPIES OF JOB” is a value indicating the number of copies output in the print job.

The value of the item “NUMBER OF PAGES OF JOB” is a value indicating the number of pages included in the print job.

The value of the item “NUMBER OF DEFECT-DETECTED PAGES OF JOB” is a value indicating the number of pages with defects detected in the print job.

FIG.17is a first diagram illustrating a defect detection page list according to the first embodiment of the present disclosure.

The defect detection page list displayed in the “DEFECT DETECTION PAGE LIST” display area909includes items “DEFECT DETECTION TIME”, “NUMBER OF DEFECTIVE COPIES OCCURRED IN JOB”, “NUMBER OF DEFECTIVE PAGES OCCURRED IN JOB”, “NEARBY SLIP SHEET ID”, “COLOR PATTERN OF NEARBY SLIP SHEET”, and “RELATION OF POSITIONS OF DEFECT DETECTED PAGE AND SLIP SHEET”.

The value of the item “DEFECT DETECTION TIME” is a value indicating the time at which the defect was detected for each page.

The value of the item “NUMBER OF DEFECTIVE COPIES OCCURRED IN JOB” is a value indicating the number of copies where the defect has occurred.

The value of the item “NUMBER OF DEFECTIVE PAGES OCCURRED IN JOB” is a value indicating the number of pages where the defect has occurred.

The value of the item “NEARBY SLIP SHEET ID” is a value indicating the slip sheet ID of the slip sheet stacked nearby the page in which the defect is detected. Specifically, the nearby slip sheet ID is a slip sheet ID of a slip sheet determined to be inserted due to detection of the defect.

The value of the item “COLOR PATTERN OF NEARBY SLIP SHEET” is a value indicating a color pattern of the outer circumferential portion printed on the slip sheet stacked nearby the page in which the defect is detected. Note that at least one of the pattern image906of a color, the mark, the pattern, or the slip sheet ID is printed on the slip sheet as identification information to identify the slip sheet (second conveyance medium). Due to the identification information to identify the slip sheet (second conveyance medium), when the plurality of slip sheets is output, a user easily finds the specific slip sheet and easily reaches the defective sheet. The identification information of the slip sheet (second conveyance medium) is information to be printed on the slip sheet so as to be visible from the lateral side or the top of the ejection device such as the stacker14when the slip sheet is ejected in the ejection device and stacked between the printed sheets. The identification information is printed on an edge portion, a surround portion, or a corner of the slip sheet without borders or margins and is visually recognized even when the slip sheet overlaps with the printed sheets. Note that the identification information in the present disclosure is not limited to the above-described example, and includes information configured by a design of patterns or colors.

The value of the item “RELATION OF POSITIONS OF DEFECT DETECTED PAGE AND SLIP SHEET” is a value indicating the relation between the position of the printed page on which the defect is detected and the position at which the slip sheet is stacked. The relation of positions of the defect detected page and the slip sheet indicates the number of sheets that are sandwiched between the slip sheets and the defect detection face of the defect detected page (upper face or lower face). Note that the “DEFECT DETECTION PAGE LIST” display area909displaying the defect detection page list may further display identification information of the defective sheet such as the page ID or the sheet ID, or information included in the job information ofFIG.8such as the job ID, in association with each defect detection sheet.

The display control unit302displays identification information of the second conveyance medium (such as the pattern image of the slip sheet or the slip sheet ID), the information of the defective first conveyance medium (such as the defect occurrence information or the page ID of the defective sheet), and the information indicating the relation of stacked positions between the defective first conveyance medium and the second conveyance medium. The above-described information displayed by the display control unit302is another example of “identification information that distinguishes and associates each of the plurality of first conveyance media having defective images stacked on the ejection device, with a corresponding one of the plurality of second conveyance media stacked on the ejection device”. For example, the information in each row of the defect detection page list is the “identification information that distinguishes and associates each of the plurality of first conveyance media having defective images stacked on the ejection device, with a corresponding one of the plurality of second conveyance media stacked on the ejection device”. Further, the “identification information that distinguishes and associates each of the plurality of first conveyance media having defective images stacked on the ejection device, with a corresponding one of the plurality of second conveyance media stacked on the ejection device” may include both information displayed by the display control unit302and identification information of the slip sheet on which the image is to be formed. Due to the above-described configuration, after viewing the displayed information, the user visually recognizes the information printed on the slip sheet stacked on the ejection device, easily distinguishes and confirms the plurality of slip sheets, and easily finds the specific defective sheet that the user seeks.

FIG.18is a diagram illustrating a defect detection image according to the first embodiment.

The “DEFECT DETECTION IMAGE” display area910inFIG.18displays read image data of a printed page designated in the defect detection page list illustrated inFIG.17to which a display911indicating the defect detection portion is added.

FIG.19is a second diagram illustrating the defect detection page list according to the first embodiment.

As illustrated inFIG.19, the display control unit302of the inspection device13displays the defect detection page list that does not include the items related to the slip sheet immediately after detecting the first page with the defect.

FIG.20is a third diagram illustrating the defect detection page list according to the first embodiment.

The display control unit302of the inspection device13receives the slip sheet job information from the printer11. When the “JOB TYPE” included in the slip sheet job information is “SLIP SHEET FOR DEFECT DETECTION IDENTIFICATION”, the display control unit302of the inspection device13sets the value of the item “SLIP SHEET ID” included in the job information to the value of the item “NEARBY SLIP SHEET ID” in response to the receipt of the slip sheet job information from the printer11. Further, the display control unit302sets a mark of a color corresponding to the value of the item “CONTENTS” of the slip sheet print information903to the value of the item “COLOR PATTERN OF NEARBY SLIP SHEET” and then sets the relation of stacking positions between the slip sheet and the printed page in which the defect is detected to the value of the item “RELATION OF POSITIONS OF DEFECT DETECTED PAGE AND SLIP SHEET” to update the display contents.

FIG.21is a diagram illustrating a setting screen of an insertion interval of the slip sheet according to the first embodiment.

The setting screen912is a screen via which the ejection setting unit315receives a setting of the insertion interval of the slip sheet. The setting screen912is a screen used by the display control unit302of the inspection device13. The number of printed sheets to be output is input as insertion interval on the setting screen912. When the ejection setting unit315receives the setting, the storage unit305stores information indicating the insertion interval of the slip sheet. Since the ejection setting unit315receives the setting, the printer11does not eject the slip sheet even if the defect is detected during the slip sheet insertion interval after the previous slip sheet is ejected. Note that the insertion interval of the slip sheet may be set based on the number of outputs (printed sheets), an output time (period), or the number of j obs.

FIG.22is a fourth diagram illustrating the defect detection page list according to the first embodiment.

As another example of display of the defect detection page list, the display control unit302may form a slip sheet image using color information and display the slip sheet image as the value of the item “COLOR PATTERN OF NEARBY SLIP SHEET”. In addition, the display control unit302may display the color name in text character as the value of the item “COLOR PATTERN OF NEARBY SLIP SHEET”. AlthoughFIG.22illustrates an example in which the defect detection page list is displayed so that rows are added downward in the order of detection, the defect detection page list may be displayed so that rows are added upward in the order of detection along with the manner of accumulation of the sheets on the stacker14.

FIG.23is a diagram illustrating an appearance of ejected sheets according to the first embodiment.

The ejected sheets are stacked on the stacker14. While the outer circumferential portion of a sheet generally has a single color such as white, the outer circumferential portion of the slip sheet has a pattern of two colors alternately printed, so that the slip sheet is found immediately. Further, even when the plurality of slip sheets is printed, the user easily distinguishes the slip sheets having patterns with different colors. Further, the user immediately finds the target slip sheet from the color pattern displayed on the operation panel133as the value of the item “COLOR PATTERN OF NEARBY SLIP SHEET” of the defect detection page list.

In order to prompt the user to find the defective first conveyance medium, for example, it is effective to stack a second conveyance medium such as the slip sheet at a position adjacent to the defective first conveyance medium. However, in this method, in order to eject the first conveyance medium after the defect determination is completed, a physical portion such as a conveyance passage having a sufficient length for obtaining a time for defect detection is to be provided, and it is difficult to achieve this configuration.

Further, when the number of the stacked conveyance media is very large, it is difficult to find out the defective first conveyance medium by simply displaying the position where the defective first conveyance medium is stacked.

On the other hand, according to the image forming system1of the present embodiment, the second conveyance medium such as the slip sheet and the defective first conveyance medium do not have to be adjacent to each other, and thus a physical portion such as the conveyance passage having the sufficient length as described above is not to be provided.

Further, since the relation of the positions of the defect detected page and the slip sheet is displayed on the operation panel as the value of the item “RELATION OF POSITIONS OF DEFECT DETECTED PAGE AND SLIP SHEET” of the defect detection page list, the user is prompted to find the defect detected sheet by counting the number of sheets from the slip sheet found by the user. Since the number of sheets between the slip sheet and the defective sheet is relatively small in general, it is not difficult to count the number of sheets.

As described above, the image forming system1of the present embodiment prompts the user to find the defective first conveyance medium.

Second Embodiment

Next, descriptions are given of the image forming system1according to a second embodiment of the present disclosure, with reference to the drawings. The configuration of the second embodiment is basically similar to the configuration of the first embodiment. Different from the first embodiment, in the configuration of the image forming system1according to the second embodiment, a slip sheet that has already been printed to indicate a defect is used to display the defect in subsequent printing. Thus, in the following description of the second embodiment, differences from the first embodiment are mainly described. The components of the second embodiment having the same functional configurations as the components of the first embodiment are denoted by the same reference numerals used in the description of the first embodiment, and descriptions of the components similar to the first embodiment are omitted in the second embodiment.

FIG.24is a first diagram illustrating the defect detection page list according to a second embodiment of the present disclosure.

The ejection control unit314according to the present embodiment uses the slip sheet that has already been printed to indicate the defect to display the defect of subsequent printing. Specifically, as illustrated inFIG.24, the display control unit302displays the relation of the positions of the defect detected page and the slip sheet already ejected not only for a first defect (first entry inFIG.24) that triggered the ejection of the slip sheet ID but also for a second defect (second entry inFIG.24) detected after the detection of the first defect. The relation of positions of the defect detected page and the slip sheet already ejected is displayed even the ejection control unit314determines that the slip sheet is not to be inserted at the time of the detection of the second defect (NO in step S303inFIG.11).

As a result, the same slip sheet ID (for example, 0001) is included in a plurality of entries (for example, the first entry and the second entry inFIG.24) in the defect detection page list.

When correspondence between the slip sheet and the defect detection page is one-to-many, it is to determine which slip sheet corresponds to each defect detection page is used to display the relation of positions of the defect detection page and the slip sheet. Then, the display control unit302specifies the slip sheet stacked closest to the defect detection page. Specifically, the display control unit302calculates the number of sheets between the slip sheet stacked on the stacker14and the defect detection page based on the job information for the printed slip sheet received from the printer11, and then specifies the slip sheet having the smallest calculated number of sheets as the closest slip sheet. Thus, the slip sheet ID of the slip sheet specified in this manner is displayed as the value of the item “NEARBY SLIP SHEET ID” of the defect detection page list.

FIG.25is a second diagram illustrating the defect detection page list according to the second embodiment.

In the present embodiment, the display control unit302may form a slip sheet image using color information and display the slip sheet image as the value of the item “COLOR PATTERN OF NEARBY SLIP SHEET” as in the same manner inFIG.22. Further, the display control unit302may display the color name in text character as the value of the item “COLOR PATTERN OF NEARBY SLIP SHEET”. AlthoughFIG.25illustrates an example in which the defect detection page list is displayed so that rows are added downward in the order of detection, the defect detection page list may be displayed so that rows are added upward in the order of detection in accordance with images stacked on the stacker14.

According to the image forming system1of the present embodiment, the slip sheet that has already been printed to indicate the defect is used to display the defect in subsequent printing. Due to the above-described configuration, a plurality of defective portions is displayed with one slip sheet, and even when the plurality of defects occurs, the number of slip sheets to be inserted is determined appropriately.

Each of the above-described embodiments describes the examples in which the image forming apparatus10performs printing on the slip sheet. As a result, generating a slip sheet with an outstanding color tone using inexpensive sheets is achieved, configuration changes such as changes in color patterns is flexibly achieved, and saving the effort of separately preparing sheets for the slip sheet. Pre-printed sheets or materials other than sheets may be ejected as defect indicators. For example, the slip sheet ID may be written in a bundle of the plurality of sheets, the plurality of sheets may be placed on the sheet feeding tray so as to be ejected in the order of the slip sheet IDs, and the slip sheet fed from the sheet feeding tray may be inserted into the printed sheets. As a result, the printing cost of the slip sheet is reduced.

In each of the above-described embodiments, the DFE50, the inspection device13and the printer11are configured to share the above-described processing steps in various combinations. Further, the elements of the DFE50, the inspection device13and the printer11may be integrated into one apparatus or may be separately disposed in a plurality of different apparatuses.

For example, the above-described embodiments describe the examples in which the inspection device13generates the slip sheet print information903and the printer11generates print job data for the slip sheet based on the slip sheet print information903. As a result, the inspection device13reduces the load of processing other than inspection and avoids a delay in the speed of inspection. However, the inspection device13may generate print job data for the slip sheet and transmit the print job data to the printer11. In this case, the inspection device13generates image data for slip sheet printing in a format such as portable document format (PDF) and transmits the image data to the printer11. Due to the above-described configuration, the printer11does not include a special mechanism for printing on a slip sheet, thus a system is easily introduced.

In an embodiment, the DFE50or the inspection device13may be configured as an information processing system including a plurality of computing devices such as a server cluster. The plurality of computing devices is configured to communicate with one another via any type of communication link, including a network or shared memory to implement the processing described in the present invention.

Each of the functions of the described embodiments may be implemented by one or more processing circuits or circuitry. Processing circuitry includes a programmed processor, as a processor includes circuitry. A processing circuit also includes devices such as an application specific integrated circuit (ASIC), a digital signal processor (DSP), a field programmable gate array (FPGA), and conventional circuit components arranged to perform the recited functions.

In the above-described embodiments, the stacker14includes one sheet ejection tray141. However, in other embodiments, the stacker14may include the plurality of sheet ejection trays141. For example, the stackers14and the sheet ejection trays141illustrated inFIGS.26to29are configured to eject and stack printed sheets and slip sheets and are examples of the ejection device according to the present disclosure. In the ejection and stacking method illustrated inFIG.26, printed sheets and slip sheets are collectively ejected onto one sheet ejection tray141. Thus, even in the ejection, a plurality of printed sheets having defects and the plurality of slip sheets are easily distinguished from each other.

Further, when the sheets are collectively ejected to one sheet ejection tray, the plurality of printed sheets having defects are included across the plurality of jobs or a plurality of copies of the same job which are continuously ejected. However, the user easily grasps the position of the defective sheet by ejecting the plurality of slip sheets that is distinguished from each other even if a relatively large number of sheets is ejected. Further, as illustrated inFIG.27, the slip sheets and the printed sheets may be separately ejected to the plurality of sheet ejection trays141. Further, for example, as illustrated inFIG.28, the slip sheet ejected to the upper sheet ejection tray141may indicate that the image that has the defect in the printed sheets of the lower sheet ejection tray141.

Further, in a case where sheets are ejected to the plurality of sheet ejection trays141, the sheets are ejected separately to the sheet ejection trays141for each print job. In this case, as illustrated inFIG.29, when the slip sheet is ejected to the uppermost position of the sheet ejection trays141, the slip sheet is not overlaid by the upper printed sheets, and the visibility of the slip sheet is enhanced, so that the slip sheet is more easily found. In this case, when the slip sheet is not ejected at the uppermost position (the lowermost sheet ejection tray141inFIG.29), the user finds that no defective sheet has been detected in the print job, thereby enhancing the workability.

In addition, as illustrated inFIG.30, in the case where sheets are separately ejected to the plurality of sheet ejection trays141, the display control unit302may display identification information (tray A, tray B) of the ejected sheet ejection tray141or the level of sheet ejection tray (the first tray from the top, the second tray from the top) for each cover of printed sheets with defects. This configuration indicates the sheet ejection tray141to which each of the defective sheet and the slip sheet is ejected.

Each of the functions of the described embodiments may be implemented by one or more processing circuits or circuitry. Processing circuitry includes a programmed processor, as a processor includes circuitry. A processing circuit also includes devices such as an application specific integrated circuit (ASIC), a digital signal processor (DSP), a field programmable gate array (FPGA), and conventional circuit components arranged to perform the recited functions.