Image forming system and inspection apparatus

Abstract

To facilitate discrimination of an abnormal sheet out of a plurality of ejected sheets.SOLUTION: An image forming device 101 comprises: a printing device 107; an inspecting device 109 that inspects an image of a sheet on which an image is formed by the printing device 107; and a stack tray 341 and an escape tray 346 to which sheets are ejected. The image forming device 101 is configured so that a normal sheet is ejected to the stack tray 341 and an abnormal sheet and a subsequent sheet following the abnormal sheet are ejected to the escape tray 346. A display 241 notifies a user of prescribed information showing a position of the abnormal sheet of the plurality of sheets placed on the escape tray 346.SELECTED DRAWING: Figure 14

Description

Technical Field

[0001] The present invention relates to an image forming system for forming an image on a sheet and an inspection device for inspecting the image of the sheet.

Background Art

[0002] In recent years, an image forming system has been known that can form an image on a sheet by an image forming apparatus and transport the sheet on which the image has been formed to an inspection device connected to the image forming apparatus for inspection (product inspection). Patent Document 1 describes an inspection device that reads an image of a sheet formed by an image forming apparatus and determines whether the image of the sheet is normal. The inspection device can detect, for example, missing barcodes or grids, missing images, printing defects, missing pages, color misregistration, etc. Such an image forming system can discharge a sheet (hereinafter referred to as an abnormal sheet) determined to have an abnormality in the image by the inspection device to a discharge destination different from that of a sheet with a normal image (hereinafter referred to as a normal sheet).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when the inspection device detects an abnormal sheet, in order to prevent the page order of the products from being shifted, not only the abnormal sheet but also the subsequent fed sheets after the abnormal sheet are discharged to the same discharge destination as the abnormal sheet. In the case of such a discharge method, the discharge destination where the abnormal sheet is discharged contains a mixture of the abnormal sheet and the subsequent sheets of the abnormal sheet. Therefore, there is a problem that it is difficult for the user to discriminate which of the discharged sheets is the abnormal sheet.

[0005] Therefore, the object of the present invention is to provide an image forming system that makes it easy to determine which of the discharged sheets is an abnormal sheet. [Means for solving the problem]

[0006] One aspect of the present invention includes an image forming means for forming an image on a sheet, an inspection means for inspecting the image of the sheet formed by the image forming means, a first discharge unit and a second discharge unit from which sheets whose images have been inspected by the inspection means are discharged, a control means for controlling the destination of the sheets so that normal sheets whose images are determined to be normal by the inspection means are discharged to the first discharge unit, and abnormal sheets whose images are determined to be abnormal by the inspection means and subsequent sheets following the abnormal sheets are discharged to the second discharge unit, and a predetermined information indicating the position of the abnormal sheet among a plurality of sheets stacked in the second discharge unit. Report It includes a notification means for notifying the user, The inspection means does not perform image inspection on subsequent sheets following the abnormal sheet, and the notification means notifies the user of the inspection results for all image-formed sheets, excluding the subsequent sheet for which the image inspection by the inspection means was not performed, in addition to the predetermined information. The image forming system is characterized in that all the image-formed sheets include sheets discharged to the first discharge unit and sheets discharged to the second discharge unit. [Effects of the Invention]

[0007] According to the present invention, it is possible to easily determine which of the discharged sheets is an abnormal sheet. [Brief explanation of the drawing]

[0008] [Figure 1] This is an overall diagram of the hardware configuration of the image forming system according to this embodiment. [Figure 2] This is a block diagram showing the system configuration of the image forming system according to this embodiment. [Figure 3] This is a schematic cross-sectional view of the image forming apparatus according to this embodiment. [Figure 4] This is an example of the display screen before the correct image is registered in the inspection device. [Figure 5]This is an example of the display screen used when registering the correct image in the inspection device. [Figure 6] This is an example of a display screen showing the inspection device reading the correct image. [Figure 7] This is an example of the display screen after the inspection device has read the correct image. [Figure 8] This is an example of the display screen when setting inspection skip areas. [Figure 9] This is an example of the display screen when setting up inspection parameters. [Figure 10] This is an example of a display screen shown when the inspection device determines that the sheet image is normal. [Figure 11] This is an example of a display screen shown when the inspection device determines that the image on the sheet is abnormal. [Figure 12] This diagram shows the destination of the sheet during purge and recovery mode. [Figure 13] This is a flowchart showing the processing steps for the discharge operation of a large-capacity stacker. [Figure 14] This is a diagram illustrating an example of the abnormal sheet position display screen. [Figure 15] This flowchart shows the process of resetting the paper count in the escape tray. [Figure 16] This is a diagram illustrating an example of the abnormal sheet position display screen. [Figure 17] This is a diagram illustrating an example of the abnormal sheet position display screen. [Modes for carrying out the invention]

[0009] The embodiments of the present invention will be described in detail below with reference to the attached drawings. Note that the following embodiments are merely examples of the present invention and do not limit the technical scope of the present invention.

[0010] <Image Forming System> FIG. 1 is an overall view of the hardware configuration of an image forming system 100 according to the present embodiment. The image forming system 100 includes an image forming apparatus 101 and an external controller 102. The image forming apparatus 101 and the external controller 102 are communicably connected via an internal LAN 105 and a video cable 106. The external controller 102 is communicably connected to a PC 103 via an external LAN 104, and a print instruction is given from the PC 103 to the external controller 102.

[0011] A printer driver having a function of converting print data into a print description language that can be processed by the external controller 102 is installed in the PC 103. A user who performs printing can give a print instruction from various applications via the printer driver. The printer driver transmits print data to the external controller 102 based on a print instruction from the user. When the external controller 102 receives a print instruction from the PC 103, it performs data analysis and rasterization processing, inputs the print data to the image forming apparatus 101, and gives a print instruction.

[0012] The image forming apparatus 101 includes a printing apparatus 107, an inserter 108, an inspection apparatus 109 (inspection device), and a large-capacity stacker 110. The printing apparatus 107 forms an image on a sheet based on an instruction from an external controller 102. The inserter 108 inserts an insertion sheet between a plurality of sheets conveyed from the printing apparatus 107. The inspection apparatus 109, which is an inspection means, reads an image of a sheet conveyed from the printing apparatus 107 and compares it with a pre-registered correct image to determine whether the image of the sheet is normal or not. Here, the correct image is image data for the inspection apparatus 109 to compare with the image of the sheet, and is image data obtained by previously reading a sheet normally printed by the image forming apparatus 101. Also, the correct image may be image data sent from a PC 103 to the external controller 102. In the following description, a sheet determined to be normal by the inspection apparatus 109 is called a normal sheet, and a sheet determined to be abnormal by the inspection apparatus 109 is called an abnormal sheet. The large-capacity stacker 110 is a large-capacity stacker that stacks sheets conveyed from the printing apparatus 107.

[0013] Note that the image forming system 100 in the present embodiment has a configuration in which an external controller 102 is connected to the image forming apparatus 101, but the image forming system 100 is not limited to a configuration with an external controller 102 connected. That is, the image forming apparatus 101 may be connected to an external LAN 104, and printing data that can be processed by the image forming apparatus 101 may be transmitted from the PC 103. In this case, in the image forming apparatus 101, data analysis and rasterization processing are performed, and printing processing is executed.

[0014] Also, the image forming apparatus 101 in the present embodiment includes a printing apparatus 107, an inserter 108, an inspection apparatus 109, and a large-capacity stacker 110, but the configuration of the image forming apparatus 101 is not limited to this. For example, the image forming apparatus 101 may have a configuration in which another post-processing apparatus such as a folding apparatus is connected to the large-capacity stacker 110. Also, the image forming apparatus 101 may have a configuration in which the inspection apparatus 109 is directly connected to the printing apparatus 107 without having the inserter 108.

[0015] Figure 2 is a block diagram showing the system configuration of the image forming apparatus 101, the external controller 102, and the PC 103. First, the configuration of the printing apparatus 107 of the image forming apparatus 101 will be described. The printing apparatus 107 includes a communication I / F 217, LAN I / F 218, video I / F 220, HDD 221, CPU 222, memory 223, operation unit 224, and display 225. Furthermore, the printing apparatus 107 includes a document exposure unit 226, a laser exposure unit 227, an image formation unit 228, a fixing unit 229, and a feeding unit 230. Each component of the printing apparatus 107 is connected via a system bus 231. The communication I / F 217 is connected to the inserter 108, the inspection device 109, and the large-capacity stacker 110 via a communication cable 254, and communicates for the control of each device. The LAN I / F 218 is connected to the external controller 102 via an internal LAN 105, and communicates print data and other information. The video interface 220 is connected to the external controller 102 via the video cable 106 for communication of image data and other information. The HDD 221 is a storage device where programs and data are stored. The CPU 222 comprehensively controls image processing and printing based on the programs stored in the HDD 221. The memory 223 stores programs and image data necessary for the CPU 222 to perform various processes and operates as a work area. The operation unit 224 accepts input of various settings and operation instructions from the user. The display 225 shows setting information of the image processing device and the processing status of print jobs.

[0016] The document exposure unit 226 processes the reading of documents when using the copy or scan functions. Specifically, it reads an image by illuminating the paper placed by the user with an exposure lamp and capturing it with a CCD reading unit. The laser exposure unit 227 is a device that performs primary charging and laser exposure in order to irradiate the photosensitive drum with laser light in order to transfer the toner image. The laser exposure unit 227 first performs primary charging, which charges the surface of the photosensitive drum to a uniform negative potential. Next, the laser driver irradiates the photosensitive drum with laser light while adjusting the reflection angle with a polygon mirror. This forms an electrostatic latent image on the photosensitive drum. The image creation unit 228 is a device for transferring toner to paper and consists of a developing unit, a transfer unit, a toner supply unit, etc., which transfers the toner on the photosensitive drum to the paper. The developing unit attaches negatively charged toner from the developing cylinder to the electrostatic latent image on the surface of the photosensitive drum, making it a visible image. The transfer unit performs primary transfer by applying a positive potential to the primary transfer roller and transferring the toner on the surface of the photosensitive drum to the transfer belt. The transfer unit also performs secondary transfer by applying a positive potential to the secondary transfer outer roller and transferring the toner on the transfer belt to the paper. The fixing unit 229 is a device for dissolving and fixing the toner on the paper using heat and pressure, and consists of a heating element, fixing belt, pressure belt, etc. The feeding unit 230 is a device for feeding paper, and the paper feeding and transport operations are controlled by rollers and various sensors.

[0017] Next, the configuration of the inserter 108 of the image forming apparatus 101 will be described. The inserter 108 consists of a communication interface 232, a CPU 233, a memory 234, and a paper feed control unit 235, and each component is connected via a system bus 236. The communication interface 232 is connected to the printing apparatus 107 via a communication cable 254 and performs the communication necessary for controlling the inserter 108. The CPU 233 performs various controls necessary for feeding according to the control program stored in the memory 234. The memory 234 is a storage device in which the control program is stored. The paper feed control unit 235 controls the feeding section of the inserter 108 and the transport of paper transported from the printing apparatus 107, while controlling the rollers and sensors based on instructions from the CPU 233.

[0018] Next, the configuration of the inspection device 109 of the image forming apparatus 101 will be described. The inspection device 109 consists of a communication interface 237, a CPU 238, a memory 239, an imaging unit 240, a display 241, and an operation unit 242, and each component is connected via a system bus 243. The communication interface 237 is connected to the printing device 107 via a communication cable 254 and performs the communication necessary for controlling the inspection device 109. The CPU 238 performs various controls necessary for inspection according to the control program stored in the memory 239. The memory 239 is a storage device in which the control program is stored. The imaging unit 240 photographs the paper transported to the printing device 107 based on instructions from the CPU 238. The CPU 238 compares the image taken by the imaging unit 240 with the correct image stored in the memory 239 to determine whether the printed image is normal or not. The display 241 displays the inspection results, setting screens, etc. The control unit 242 is operated by the user and receives instructions such as changing the settings of the inspection device 109 and registering correct images.

[0019] Next, the configuration of the large-capacity stacker 110 of the image forming apparatus 101 will be described. The large-capacity stacker 110 consists of a communication interface 244, a CPU 245, a memory 246, and a paper ejection control unit 247, and each component is connected via a system bus 248. The communication interface 244 is connected to the printing apparatus 107 via a communication cable 254 and performs the communication necessary for controlling the large-capacity stacker 110. The CPU 245 performs various controls necessary for paper ejection according to the control program stored in the memory 246. The memory 246 is a storage device in which the control program is stored. The paper ejection control unit 247, as a control means, performs control to transport the paper transported to the large-capacity stacker 110 to the stack tray 341 or the escape tray 346 based on instructions from the CPU 245.

[0020] Next, the configuration of the external controller 102 will be described. The external controller 102 consists of a CPU 208, memory 209, HDD 210, keyboard 211, display 212, LAN I / F 213, LAN I / F 214, and video I / F 215. Each component of the external controller 102 is connected via the system bus 216. The CPU 208 comprehensively performs processes such as receiving print data from the PC 103, RIP processing, and sending print data to the image forming apparatus 101, based on programs and data stored in the HDD 210. The memory 209 stores programs and data necessary for the CPU 208 to perform various processes and operates as a work area. The HDD 210 stores programs and data necessary for operations such as printing. The keyboard 211 is a device for inputting operation instructions for the external controller 102. The display 212 displays information such as the applications being executed by the external controller 102 as still images and video signals. LANI / F213 is connected to PC103 via external LAN104 and performs communication such as print commands. LANI / F214 is connected to image forming apparatus 101 via internal LAN105 and performs communication such as print commands. Video I / F215 is connected to image forming apparatus 101 via video cable 106 and performs communication such as print data.

[0021] Next, the configuration of PC103 will be described. PC103 consists of a CPU201, memory202, HDD203, keyboard204, display205, and LANI / F206, with each component connected via a system bus207. The CPU201 creates print data and executes print commands based on document processing programs stored in the HDD203. The CPU201 also comprehensively controls each device connected to the system bus. The memory202 stores programs and data necessary for the CPU201 to perform various processes and operates as a work area. The HDD203 stores programs and data necessary for operations such as printing. The keyboard204 is a device for inputting operation commands for PC103. The display205 displays information such as the applications running on PC103 as still images and video signals. The LANI / F206 is connected to the external controller102 via the external LAN104 and performs communication such as print commands.

[0022] In the above description, the external controller 102 and the image forming apparatus 101 are connected via the internal LAN 1905 and video cable 106. However, any configuration that allows for the transmission and reception of data necessary for printing is acceptable; for example, a configuration with only a video cable connection is also acceptable. Furthermore, memory 202, memory 209, memory 223, memory 234, memory 239, and memory 246 can each be any storage device for holding data or programs. For example, a configuration using volatile RAM, non-volatile ROM, an internal HDD, an external HDD, or a USB memory device is also acceptable.

[0023] <Image forming apparatus> Next, the image forming apparatus 101 will be described using Figure 3. Figure 3 is a schematic cross-sectional view of the image forming apparatus 101. The printing apparatus 107 has feed decks 301 and 302. Various sheets for printing are stored in the feed decks 301 and 302. The feed decks 301 and 302 are capable of separating only the top sheet of the stored sheets and transporting it to the sheet transport path 303. The developing stations 304 to 307 use colored toners Y, M, C, and K, respectively, to form a toner image in order to form a color image. The toner image formed by the developing stations 304 to 307 is first transferred to the intermediate transfer belt 308. The intermediate transfer belt 308 rotates clockwise in Figure 3, and at the secondary transfer position 309, the toner image is transferred to the sheet transported from the sheet transport path 303. The developing stations 304 to 307 and the intermediate transfer belt 308 function as image forming means in this embodiment. The display 225 displays information for the printing status and settings of the image forming apparatus 101. The first fixing unit 311 is equipped with a pressure roller and a heating roller, and as the sheet passes between the rollers, the toner is melted and pressed, fixing the toner image to the sheet. After passing through the first fixing unit 311, the sheet is transported to the inserter 108 via the sheet transport paths 312 and 315. If further melting and pressing are required for fixing depending on the type of sheet, after passing through the first fixing unit 311, the sheet is transported to the second fixing unit 313 via the sheet transport path above, where additional melting and pressing is performed. After that, it is transported to the inserter 108 via the sheet transport paths 314 and 315. If an image is to be formed on both sides of the sheet, the sheet that has been inverted in the sheet inversion path 316 is transported to the double-sided transport path 317, and the second image is transferred at the secondary transfer position 309.

[0024] The inserter 108 inserts insertion sheets between sheets being transported from the printing device 107. The inserter 108 is equipped with an inserter tray 321, and the insertion sheets fed from the inserter tray 321 via the sheet transport path 322 are joined to the sheet transport path 323. This allows the inserter 108 to insert insertion sheets at any position into a series of sheets being transported from the printing device 107 and transport them to a subsequent device. In addition, the inserter 108 can transport sheets to the inspection device 109 by feeding them from the inserter tray 321, independently of the printing operation. In other words, the inserter 108 can transport sheets to the inspection device 109 that are different from the sheets that are image-formed and discharged by the printing device 107.

[0025] The inspection device 109 reads the image of the sheet that has been transported through the sheet transport path 323 of the inserter 108 and determines whether the image of the sheet is normal or not. Inside the inspection device 109, reading units 331 and 332 are arranged facing each other. Reading unit 331 reads the image of the first side (top side) of the sheet, and reading unit 332 reads the image of the second side (bottom side) of the sheet. When the sheet being transported by the sheet transport path 333 reaches a predetermined position, the inspection device 109 reads the image of the sheet using reading units 331 and 332 and determines whether the image of the sheet is normal or not. The display unit, display 241, displays the inspection results performed by the inspection device 109 and other information. In this embodiment, the display 241 functions as a notification means to notify the user of predetermined information.

[0026] The large-capacity stacker 110 has a stack tray 341 as a first discharge section from which sheets are discharged. The large-capacity stacker 110 also has a shift function that discharges the sheets to be discharged to a position shifted by a predetermined amount relative to the sheets already stacked on the stack tray 341. Sheets that have passed through the inspection device 109 are loaded onto the stack tray 341 via the sheet transport path 344 and the sheet transport path 345.

[0027] Furthermore, the large-capacity stacker 110 has an escape tray 346 as a second discharge section where sheets are discharged. The escape tray 346 is a discharge section where abnormal sheets are discharged when the inspection device 109 determines that a sheet inspected is an abnormal sheet. When an abnormal sheet is discharged to the escape tray 346, the abnormal sheet is transported from the sheet transport path 344 to the escape tray 346 via the sheet transport path 347. If a post-processing device is connected downstream of the large-capacity stacker 110, the sheets are transported to the post-processing device via the sheet transport path 348. The large-capacity stacker 110 has a reversing section 349 for reversing the front and back sides of the sheets. The reversing section 349 is used when stacking sheets onto the stack tray 341. When the large-capacity stacker 110 transports sheets to the escape tray 346 or a subsequent post-processing device, the reversing operation at the reversing section 349 is not performed.

[0028] The escape tray 346 is equipped with a sheet presence / absence detection sensor 346a. The sheet presence / absence detection sensor 346a, as a detection means, is a sensor for detecting the presence or absence of a sheet in the escape tray 346. The CPU 245 of the large-capacity stacker 110 can detect when a sheet has been removed from the escape tray 346 based on the signal from the sheet presence / absence detection sensor 346a. Specifically, when the sheet presence / absence detection sensor 346a switches from a state in which it detects a sheet to a state in which it does not detect a sheet, the CPU 245 determines that a sheet has been removed from the escape tray 346.

[0029] <Operation of inspection equipment> Figures 4 to 11 show examples of screens displayed on the display 241 of the inspection device 109. The inspection device 109 inspects the image of the sheet transported to the inspection device 109 based on predetermined set inspection items. The sheet image inspection is performed by comparing the correct image registered in the memory 239 with the sheet image read by the reading units 331 and 332. Methods for comparing images include comparing pixel values ​​for each image position, comparing the position of objects by edge detection, and extracting character data by OCR (Optical Character Recognition). Inspection items include misalignment of print position, image color, image density, streaks and blurring, and missing prints.

[0030] Figure 4 shows an example of the display screen shown on the display 241 of the inspection device 109 when the inspection device 109 is started. In the display screen shown in Figure 4, the display 241 shows information that a correct image has not been registered and that registration of a correct image is required to start the inspection. If a correct image has already been registered, information that the inspection can be started is displayed. In addition, the display 241 displays the correct image that has been registered in the image display unit 402. In Figure 4, the image display unit 402 shows information that a correct image has not been registered. Button 403 is a button to call up the correct image registration screen. Button 404 is a button to call up the inspection settings screen. Button 405 is a button to call up the inspection result confirmation screen. Button 406 is a button to instruct the start of the inspection.

[0031] Figure 5 shows an example of the display screen shown on the display 241 of the inspection device 109 when a user registers a correct image. The display screen shown in Figure 5 is displayed on the display 241 in accordance with the selection of button 403 in Figure 4. The sheet quantity setting unit 501 is used to set the number of sheets per print job in which inspection is performed. In the case of a print job with two or more sheets per print job, multiple images can be registered as correct images in the inspection device 109. The surface setting unit 502 is used to set the surface of the sheet that the inspection device 109 will inspect. The user can use the surface setting unit 502 to set whether to inspect images on both sides of the sheet, only the image on the front side, or only the image on the back side. Even if only one side of the sheet is printed, it is possible to set the device to perform a double-sided inspection in order to check for any debris on the unprinted side. Button 503 is a button for instructing the registration of a correct image. When button 503 is selected, the inspection device 109 reads the image of the conveyed sheet and registers the image data as the correct image.

[0032] Figure 6 shows an example of the display screen shown on the display 241 when the inspection device 109 is reading an image from a sheet to register the correct image. The screen shown in Figure 6 is displayed depending on whether button 503 in Figure 5 is selected. Button 601 is used to instruct the device to stop reading. If button 601 is selected, the inspection device 109 stops reading the image, and the display 241 returns to the display screen shown in Figure 4.

[0033] Figure 7 shows an example of the display screen shown on the display 241 after the reading of the correct image is complete. The image display unit 701 displays the image of the sheet read by the inspection device 109. If there are multiple images, the displayed image can be switched using the switch button 702. Also, when performing double-sided inspection, the front and back can be switched using the switch button 703. Button 704 is a button for instructing the setting of inspection skip areas. Button 704 allows you to set areas that will not be inspected for printing where the print content of a specific area changes for each copy, such as variable data printing (VDP). Button 705 is a button for registering the image displayed on the image display unit 701 as the correct image. When button 705 is selected, the inspection device 109 registers the correct image and returns to the display screen in Figure 4. 706 is a button for canceling the reading. If button 706 is pressed, the inspection device 109 will not register the correct image, and the display 241 will return to the display screen shown in Figure 4.

[0034] Figure 8 shows an example of the inspection skip area setting screen displayed on the display 241. The display screen shown in Figure 8 is displayed on the display 241 when button 704 is selected. Area 801 indicates the inspection skip area. The user can change the position of area 801 using the position setting unit 802 and change the size of area 801 using the size setting unit 803. Button 804 is for registering the setting of the inspection skip area. When button 804 is selected, the inspection device 109 registers area 801 as an inspection skip area, and the display 241 returns to the display screen of Figure 7. Button 805 is for registering yet another inspection skip area. This allows the inspection device 109 to register multiple inspection skip areas for a single image data. Button 806 is for canceling the setting of the inspection skip area. When button 806 is selected, the display 241 returns to the display screen of Figure 7.

[0035] Figure 9 shows an example of a settings screen for configuring inspection settings. The display screen shown in Figure 9 is shown on the display 241 when button 404 is selected. The level setting unit 901 is used to set the inspection level. The higher the inspection level set by the level setting unit 901, the more the inspection device 109 will determine an abnormal sheet based on even small differences between the correct image and the read image. The type setting unit 902 is used to set the inspection type. The user can set the inspection items using the type setting unit 902. In the display screen shown in Figure 9, the type setting unit 902 is set to inspect position, color, streaks, and omissions, but not density. Button 903 is used to confirm the inspection settings. When button 903 is selected, the inspection device 109 registers the inspection settings, and the display 241 returns to the display screen shown in Figure 4.

[0036] Figure 10 shows an example of a display screen shown on the display 241 during inspection by the inspection device 109. The screen shown in Figure 10 is displayed when button 406 in Figure 4 is selected. The image display unit 1001 displays the image of the sheet read by the inspection device 109. The result display unit 1002 displays the inspection result, which is a comparison of the image read by the image display unit 1001 with the correct image. In the screen shown in Figure 10, the sheet read by the inspection device 109 was determined to be normal, so "OK" is displayed in the result display unit 1002. Button 1003 is a button to instruct the end of the inspection. When button 1003 is selected, the inspection device 109 ends the inspection process, and the display 241 returns to the display screen in Figure 4. Button 1004 is a button to instruct the display of the confirmation screen for the overall job inspection results, which will be described later.

[0037] Figure 11 shows an example of a display screen when the inspection device 109 determines that the image of the sheet it reads is abnormal. In the example shown in Figure 11, a streak 1105 was detected in the image of the sheet read by the inspection device 109, so "NG" is displayed on the result display unit 1002.

[0038] <Explanation of recovery actions when an abnormal sheet is detected> Next, the operation of the image forming apparatus 101 when the inspection device 109 detects an abnormal sheet will be explained using Figure 12. As an example, we will explain the case where an abnormal sheet occurs on the 4th page in a job with 5 pages.

[0039] Figure 12(a) shows the destination of each sheet. Figure 12(b) shows the sheets discharged to the stack tray 341 and the escape tray 346, respectively. Figure 12 shows the destination of sheets when the discharge mode of the image forming apparatus 101 is set to purge and recovery mode. Purge and recovery mode is a mode in which, when the inspection device 109 determines that the image on a sheet is abnormal, the abnormal sheet is discharged to a different discharge unit than the normal sheets, and the image of the page printed on the abnormal sheet is reprinted on another sheet. As shown in Figure 12(a), in purge and recovery mode, the 1st to 3rd sheets, which are normal sheets, are discharged to the stack tray 341. On the other hand, the 4th sheet, which is an abnormal sheet, is discharged to the escape tray 346. Furthermore, the 5th sheet, which is the sheet following the abnormal sheet, is not inspected by the inspection device 109 and is discharged to the escape tray 346 in the same way as the abnormal sheet. At this point, the image forming apparatus 101 interrupts the job once. After the defective sheet and the sheets following the defective sheet (the 4th and 5th sheets) are discharged into the escape tray 346, the image forming apparatus 101 reprints the image formed on the 4th sheet (the defective sheet) onto the 6th sheet. Furthermore, it reprints the image formed on the 5th sheet (the sheet following the defective sheet) onto the 7th sheet. The inspection apparatus 109 then inspects the reprinted 6th and 7th sheets. If the reprinted sheets are normal, they are discharged into the stack tray 341. Finally, as shown in Figure 12(b), the finished product with pages 1-5 is stacked into the stack tray 341, and the defective sheet and the sheets following the defective sheet are stacked into the escape tray 346.

[0040] Thus, the process of reprinting the image formed on an abnormal sheet onto another sheet when an abnormal sheet is detected is called the recovery process. The process of ejecting the abnormal sheet to a separate ejection section from the normal sheets is called the purging process. In other words, the purge and recovery mode is a mode in which the image forming apparatus 101 performs a predetermined process that combines both the purging and recovery processes. In addition, in the purge and recovery mode, the image forming apparatus 101 does not perform inspection by the inspection device 109 on the sheet following the abnormal sheet (the fifth sheet in Figure 12), and the subsequent sheet is ejected to the escape tray 346. As a result, the page order of the output after the recovery process is in the correct order.

[0041] In addition to the purge and recovery mode, the image forming apparatus 101 can also be configured with a purge mode that performs only the purge process, and a logon-recovery mode that ejects all sheets to the stack tray 341 and records only the inspection results.

[0042] <Ejection procedure when an abnormal sheet is detected> Next, the ejection operation when an abnormal sheet is detected will be explained using the flowchart in Figure 13. Figure 13 is a flowchart processed by the CPU 245 of the large-capacity stacker 110. When a job start command is issued by the user, the CPU 245 starts processing as shown in the flowchart in Figure 13.

[0043] First, the CPU 245 receives sheet information from the inspection device 109 (S1001). The sheet information received by the CPU 245 in S1001 includes information indicating whether or not the sheet to be transported to the large-capacity stacker 110 is an abnormal sheet.

[0044] Next, CPU245 determines whether or not an abnormal sheet has occurred (S1002). In S1002, CPU245 determines whether or not an abnormal sheet has occurred based on the abnormal sheet occurrence information set in S1005, which will be described later. If CPU245 determines in S1002 that an abnormal sheet has not occurred (No. in S1002), the process proceeds to S1003.

[0045] In S1003, the CPU 245 determines whether the sheet transported to the large-capacity stacker 110 is an abnormal sheet based on the sheet information received from the inspection device 109 in S1001. If the sheet transported to the large-capacity stacker 110 is not an abnormal sheet (No. in S1003), the CPU 245 discharges the sheet into the stack tray 341 (S1004).

[0046] On the other hand, if the sheet transported to the large-capacity stacker 110 is an abnormal sheet (Yes in S1003), the CPU 245 sets abnormal sheet occurrence information (S1005). The abnormal sheet occurrence information is a flag used by the CPU 245 to determine whether or not to eject subsequent fed sheets into the escape tray 346 in purge and recovery mode. The abnormal sheet occurrence information set here is stored in memory 246. Then, the CPU 245 saves the paper count of the escape tray 346 into memory 246 (S1006). The paper count of the escape tray 346 is a count used to measure how many sheets are loaded into the escape tray 346. Next, the CPU 245 adds 1 to the paper count of the escape tray 346 (S1007). After that, the CPU 245 ejects the sheets into the escape tray 346 (S1008).

[0047] When a sheet is ejected into the escape tray 346, the CPU 245 determines whether all subsequent sheets that have been fed following the abnormal sheet have been ejected (S1009). If all subsequent sheets that have been fed have been ejected (Yes in S1009), the CPU 245 clears the abnormal sheet occurrence information set in S1005 (S1010). The process then proceeds to S1011.

[0048] When a sheet is ejected to the stack tray 341 or escape tray 346, the CPU 245 determines whether there is another sheet (S1011). If there is another sheet (Yes in S1011), the process returns to S1001 and the ejection process is repeated. If there is no next sheet (No in S1011), the CPU 245 terminates the process.

[0049] If the CPU 245 determines in S1002 that an abnormal sheet has occurred (Yes in S1002), the process proceeds to S1007. This is the process for when the sheet transported to the large-capacity stacker 110 is a subsequent sheet that has been fed after the abnormal sheet. If the sheet transported to the large-capacity stacker 110 is an abnormal sheet, the abnormal sheet occurrence information is set in S1006. Therefore, the subsequent sheets that have been fed after the abnormal sheet are discharged into the escape tray 346.

[0050] <Explanation of the inspection results display screen> Figure 14 shows an example of a screen displaying the inspection results, which is shown on the display 241 of the inspection device 109. The display screen in Figure 14 is shown on the display 241 of the inspection device 109 when the button 405 in Figure 4 is pressed.

[0051] The job display unit 1401 in the screen of Figure 14 displays the attributes of the entire job, including inspection, and the inspection results. The inspection results displayed in the job display unit 1401 are the number of normal sheets (OK) and the number of abnormal sheets (NG) in the selected job. The position display unit 1402 displays a list of information about abnormal sheets that occurred in the job. In Figure 14, the position display unit 1402 displays the serial number of the abnormal sheet, the reason for the abnormality, and the paper position of the abnormal sheet. In this embodiment, the reasons for abnormality determined in the position display unit 1402 are two types: dirt on the sheet and misalignment of the image. The position display unit 1402 displays either OK or NG for each reason.

[0052] In this embodiment, the position display unit 1402 displays the position from the bottom of the multiple sheets loaded in the escape tray 346 where the abnormal sheet generated in the job is located. Here, the information indicating the position of the abnormal sheet displayed in the position display unit 1402 is predetermined information based on the paper count of the escape tray 346 saved in S1007 of Figure 13. The paper count of the escape tray 346 corresponds to the order in which each abnormal sheet was ejected into the escape tray 346. In other words, the paper count of the escape tray 346 indicates the position from the bottom of each abnormal sheet among the multiple sheets loaded in the escape tray 346.

[0053] Button 1403 is the job selection screen for displaying inspection results. In the example in Figure 14, the inspection results for the first job out of the nine jobs whose history is saved are displayed. By operating button 1403, the user can switch the job being displayed. Button 1404 is a button that indicates that the confirmation of inspection results is complete. When button 1404 is pressed, the display screen in Figure 4 is returned.

[0054] <Action taken when a sheet is removed from the escape tray> The operation when a sheet is removed from the escape tray 346 of the large-capacity stacker 110 will be explained using the flowchart in Figure 15. Figure 15 is a flowchart processed by the CPU 245 of the large-capacity stacker 110. This flowchart is a process that is always repeated at regular intervals while the image forming apparatus 101 is executing a job.

[0055] The CPU 245 determines whether there is a sheet on the escape tray 346 based on the signal from the sheet presence detection sensor 346a (S2001). If there is no sheet on the escape tray 346 (No in S2001), the CPU 245 sets the paper count of the escape tray 346 to 1 (S2002). In other words, if there is no sheet on the escape tray 346, the CPU 245 resets the paper count of the escape tray 346. If there is a sheet on the escape tray 346 (Yes in S2001), the process proceeds to S2003. If the job is not finished (No in S2003), the process returns to S2001. The CPU 245 repeats the above process until the job is finished.

[0056] Through this process, for example, if a sheet is removed from the escape tray 346 by the user, the CPU 245 sets the paper count of the escape tray 346 to 1. As a result, if a sheet is removed from the escape tray 346 by the user in the middle of a job, predetermined information indicating the position of the abnormal sheet ejected after the sheet was removed is displayed on the position display unit 1402 in Figure 14. In other words, even if a user removes a sheet from the escape tray 346, the sheet loading state in the escape tray 346 and the paper position displayed on the display 241 of the inspection device 109 will match.

[0057] As described above, the image forming apparatus 101 of this embodiment displays predetermined information on the display 241 indicating the location of an abnormal sheet among the multiple sheets loaded in the escape tray 346. This makes it easy for the user to identify an abnormal sheet from among the multiple sheets loaded in the escape tray 346.

[0058] <Example of the display screen for inspection results> In this embodiment, an example is shown in which information indicating which sheet it is from the bottom (first) of the sheets stacked on the escape tray 346 is displayed for each abnormal sheet. However, the displayed information only needs to be able to identify the position of each abnormal sheet on the escape tray 346. Below, another example of a display screen for identifying the position of each abnormal sheet on the escape tray 346 will be described using Figures 16 and 17.

[0059] Figure 16 is another example of a screen showing inspection results displayed on the display 241 of the inspection device 109. The position display unit 1602 in Figure 16 displays information indicating how many sheets each defective sheet is located relative to the previous defective sheet. In other words, the position display unit 1602 in Figure 16 shows the position of the second defective sheet, which was ejected after the first defective sheet, relative to the first defective sheet on the escape tray 346. By checking the position display unit 1602, the user can identify the defective sheet from among the multiple sheets loaded on the escape tray 346.

[0060] Figure 17 shows yet another example of a screen displaying inspection results on the display 241 of the inspection device 109. In the screen of Figure 17, the result display unit 1701 displays the inspection results for all sheets with images formed in the selected job. The position display unit 1702 displays a list of inspection results for all defective sheets and the sheets following the defective sheets that are loaded in the escape tray 346. By checking the position display unit 1702, the user can identify the location of a defective sheet from among the multiple sheets loaded in the escape tray 346. Thus, even with the screens shown in Figures 16 and 17, it becomes easy for the user to identify a defective sheet from among the multiple sheets loaded in the escape tray 346.

[0061] In the embodiment described above, predetermined information indicating the location of an abnormal sheet among the multiple sheets loaded on the escape tray 346 is displayed on the display 241. However, the means by which the image forming apparatus 101 notifies the user of the predetermined information are not limited to this. For example, the image forming apparatus 101 may notify the user of the predetermined information by voice.

Claims

1. Image forming means for forming an image on a sheet, An inspection means for inspecting the image of the sheet formed by the image forming means, A first discharge unit and a second discharge unit from which sheets whose images have been inspected by the inspection means are discharged, A control means controls the destination of the sheets to be discharged, such that normal sheets whose images are determined to be normal by the inspection means are discharged to the first discharge unit, and abnormal sheets whose images are determined to be abnormal by the inspection means and subsequent sheets following the abnormal sheets are discharged to the second discharge unit. A notification means for notifying the user of predetermined information indicating the location of the abnormal sheet among the multiple sheets loaded in the second discharge unit, Equipped with, The image forming system is characterized in that the inspection means does not perform image inspection on subsequent sheets following the abnormal sheet, the notification means notifies the user of the inspection results for all image-formed sheets, excluding the subsequent sheets that were not inspected by the inspection means, in addition to the predetermined information, and all image-formed sheets include sheets discharged to the first discharge unit and sheets discharged to the second discharge unit.

2. The predetermined information is information indicating which position the abnormal sheet is located in from the bottom among the plurality of sheets stacked in the second discharge unit. The image forming system according to claim 1.

3. The predetermined information is information indicating the position of the second abnormal sheet, which is determined to have an image abnormality by the inspection means after the first abnormal sheet, which is determined to have an image abnormality by the inspection means, in the plurality of sheets loaded in the second discharge unit, relative to the first abnormal sheet. The image forming system according to claim 1.

4. The predetermined information is information indicating whether or not each of the plurality of sheets loaded in the second discharge unit is an abnormal sheet. The image forming system according to claim 1.

5. The notification means has a display unit that displays the predetermined information. The image forming system according to claim 1.

6. The system includes a detection means for detecting the presence or absence of a sheet in the second discharge section, The notification means, when the detection means detects that the plurality of sheets loaded in the second discharge unit have been removed from the second discharge unit, notifies the notification of predetermined information regarding another plurality of sheets loaded in the second discharge unit after the previous plurality of sheets have been removed. The image forming system according to claim 1.

7. If the inspection means determines that there is an abnormality in the image of the sheet, the control means executes a process in which, after the abnormal sheet and the subsequent sheet have been discharged to the second discharge unit, the image formed on the abnormal sheet is formed on a sheet other than the abnormal sheet by the image forming means. The image forming system according to any one of claims 1 to 6.

8. This is an inspection device that inspects images of sheets formed by an image forming apparatus. An inspection method for inspecting the image of the sheet, A control means controls the destination of the sheets so that normal sheets, whose images are determined to be normal by the inspection means, are discharged to a first discharge unit, and abnormal sheets, whose images are determined to be abnormal by the inspection means, and subsequent sheets following the abnormal sheets are discharged to a second discharge unit. A notification means for notifying the user of predetermined information indicating the location of the abnormal sheet among the multiple sheets loaded in the second discharge unit, Equipped with, The inspection means does not perform image inspection on subsequent sheets following the abnormal sheet, and the notification means notifies the user of the inspection results for all sheets with images formed on them, excluding the subsequent sheets that were not inspected by the inspection means, in addition to the predetermined information, and all sheets with images formed on them include the sheets discharged to the first discharge unit and the sheets discharged to the second discharge unit.

Images