Patent Publication Number: US-2022222499-A1

Title: Image forming system, control method thereof, and medium

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to an image forming system, a control method thereof, and a medium. 
     Description of the Related Art 
     There is known an inspection apparatus that reads a printed product printed by a printing apparatus (image forming apparatus) and inspects quality. The inspection apparatus can detect an image defect such as dirt or omission of printing, a character error, barcode quality, and the like. A product in which these defects are detected can be discriminated from a printed product free from defects by, for example, changing the discharge destination. To do inspection by the inspection apparatus, a reference image serving as the reference of a printed product free from defects needs to be registered in advance. 
     Also, for a product using cyclic paper sheets such as tab (index) paper sheets, the printing apparatus has a function (remaining tab discharge function) of forcibly discharging remaining sheets (remaining tabs). If the remaining tabs are discharged, sheets without reference image registration are added as inspection targets. Mismatching with the order of reference images expected by the inspection apparatus occurs, and the inspection results of the remaining tab sheets become NG (defective). To avoid the inspection result NG by remaining tab discharge, in a conventional technique, a technique of excluding all tab sheets from the inspection target is disclosed (Japanese Patent Laid-Open No. 2020-116746). 
     However, even if the tab sheets should be included in the inspection target, all tab sheets are excluded from the inspection target in the conventional technique. 
     SUMMARY OF THE INVENTION 
     The present invention sets a cyclic sheet used in a printed product to an inspection target and simultaneously excludes a cyclic sheet to be discharged without being used from the inspection target. 
     The present invention has the following configuration. According to one aspect of the invention, provided is an image forming system comprising: an image forming unit configured to execute a print job and form an image on a supplied sheet; and an inspection unit configured to inspect quality of the image formed in the sheet, wherein the inspection unit does not set a sheet discharged by the image forming unit without being used for the print job to a target of inspection 
     According to the present invention, it is possible to set a cyclic sheet used in a printed product to an inspection target and simultaneously exclude a cyclic sheet to be discharged without being used from the inspection target. 
     Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view showing the configuration of an information processing apparatus, an inspection apparatus, and a printing apparatus according to an embodiment; 
         FIG. 2  is a block diagram showing the configuration of the information processing apparatus, the inspection apparatus, and the printing apparatus according to the embodiment; 
         FIG. 3  is a view showing the internal configuration of the information processing apparatus, the inspection apparatus, the printing apparatus, and a large capacity stacker according to the embodiment; 
         FIG. 4  is a flowchart showing the basic operation of the inspection apparatus at the time of reference image registration according to the embodiment; 
         FIG. 5  is a flowchart showing the basic operation of the inspection apparatus according to the embodiment; 
         FIG. 6  is a flowchart showing the basic operations of the printing apparatus and an inspection unit at the time of inspection execution according to the embodiment; 
         FIG. 7  is a view showing a setting screen for a paper sheet type to be set for a paper feed deck, which is displayed on a UI panel according to the embodiment; 
         FIG. 8  is a view showing a tab sheet index count setting screen displayed on the UI panel according to the embodiment; 
         FIGS. 9A, 9B and 10  are flowcharts showing the basic operation of the remaining tab discharge function of the printing apparatus according to the embodiment; 
         FIGS. 11A and 11B  are flowcharts showing the basic operation of an inspection unit according to the first embodiment; 
         FIG. 12  is a flowchart showing the basic operation of a printing apparatus according to the second embodiment; 
         FIGS. 13A and 13B  are flowcharts showing the basic operation of an inspection unit according to the second embodiment; and 
         FIGS. 14A and 14B  are flowcharts showing the basic operations of a printing apparatus and an inspection unit at the time of inspection execution according to the third embodiment. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Hereinafter, embodiments will be described in detail with reference to the attached drawings. Note, the following embodiments are not intended to limit the scope of the claimed invention. Multiple features are described in the embodiments, but limitation is not made an invention that requires all such features, and multiple such features may be combined as appropriate. Furthermore, in the attached drawings, the same reference numerals are given to the same or similar configurations, and redundant description thereof is omitted. 
     First Embodiment 
     Image Forming System 
       FIG. 1  is a schematic view showing the configuration of an image forming system (or a printing system) including an information processing apparatus, an inspection apparatus, and a printing apparatus (also called an image forming apparatus) according to this embodiment. Note that the printing apparatus according to this embodiment will be described using an electrophotographic type printing apparatus. However, the printing apparatus according to this embodiment may be a printing apparatus of another image forming type such as an inkjet type or an offset type. 
     A printing apparatus  101  is connected to an information processing apparatus  109  via a cable  111 . The information processing apparatus  109  is connected to a client computer  110  via a network  112 . The information processing apparatus  109  may be further connected to an inspection apparatus  108 . 
     The printing apparatus  101  includes a UI panel  102 , a paper feed deck  103 , and a paper feed deck  104 . Also, an optional deck  105  including three stages of paper feed decks is connected. The printing apparatus  101  is, for example, an electrophotographic type printing apparatus. In addition, the UI panel  102  is a user interface including, for example, an electrostatic capacitance type touch panel. 
     Furthermore, the printing apparatus  101  includes an inspection unit  106  and a large capacity stacker  107 . The inspection unit is connected to the inspection apparatus  108  via a cable  113 . The large capacity stacker  107  includes a plurality of different stacking portions, for example, a main tray and a top tray, which are configured to place sheets discharged from the inspection unit  106 . Several thousand paper sheets can be stacked on the main tray at once. The large capacity stacker  107  can switch the discharge destination to one of the main tray and the top tray in accordance with an instruction from the printing apparatus  101  or the inspection apparatus  108 . The sheets are placed on the switched tray while being sequentially overlaid. Here, paper sheets are exemplified, but the sheet material is not limited to paper. 
     A print job is generated by the client computer  110 , transmitted to the information processing apparatus  109  via the network  112 , and managed by the information processing apparatus  109 . The print job is then transmitted from the information processing apparatus  109  to the printing apparatus  101  via the cable  111 , and the printing apparatus  101  performs processing of forming an image on a paper sheet. 
     Note that the client computer  110 , the information processing apparatus  109 , and the inspection apparatus  108  may be connected to the cable  111  so as to be communicable with the printing apparatus  101 . 
       FIG. 2  is a block diagram showing the control configuration of the printing apparatus  101 , the inspection unit  106 , the inspection apparatus  108 , the large capacity stacker  107 , the information processing apparatus  109 , and the client computer  110  according to this embodiment. 
     Image Forming Apparatus (Printing Apparatus)  101   
     A CPU (Central Processing Unit)  201  conducts control and operations of units in the printing apparatus  101  via a system bus  212 . The CPU  201  conducts execution of programs stored in a storage unit  205  and loaded into a RAM (Random Access Memory)  202 . The RAM  202  is a kind of general volatile storage device that the CPU  201  can directly access, and is used as the work area of the CPU  201  or another temporary data storage area. The storage unit  205  functions as a temporary storage area and a work memory when the printing apparatus operates. 
     An engine I/F  209  conducts communication with a printer engine  210  and control thereof. A paper feed deck I/F  204  conducts communication with a paper feed deck  211  and control thereof. The paper feed deck  211  is the general term of hardware configurations for the paper feed decks  103  and  104  and the optional deck  105 . A UI panel  203  is the hardware configuration of the UI panel  102 , and is a user interface configured to perform the general operation of the printing apparatus  101 . In this embodiment, the UI panel  203  includes an electrostatic capacitance type touch panel. 
     A network interface (to be referred to as an NW I/F hereinafter)  207  is connected to an NW I/F  238  of the information processing apparatus  109  via a cable  213 , and conducts communication between the information processing apparatus  109  and the printing apparatus  101 . Note that in this example, interfaces connected to the system buses  212  and  239  are directly connected to each other. The information processing apparatus  109  and the printing apparatus  101  may be connected via, for example, a network, and the connection method is not limited. A video I/F  206  is connected to a video I/F  233  via a video cable  241 , and conducts communication of image data between the information processing apparatus  109  and the printing apparatus  101 . 
     Note that the connection interface of the information processing apparatus  109  to the printing apparatus  101  may integrate the functions of the NW I/F  238  and the video I/F  233 . In addition, the connection interface of the printing apparatus  101  to the information processing apparatus  109  may integrate the functions of the NW I/F  207  and the video I/F  206 . 
     An accessory I/F  208  is connected to an accessory I/F  214  and an accessory I/F  220  via a cable  225 . That is, the printing apparatus  101  communicates with the inspection unit  106  and the large capacity stacker  107  via the accessory I/Fs  208 ,  214 , and  220 . 
     Inspection Unit  106   
     A CPU  216  conducts control and operations of units in the inspection unit  106  via a system bus  219 . The CPU  216  conducts execution of programs stored in a storage unit  247  and loaded into a RAM  217 . The RAM  217  is a kind of general volatile storage device that the CPU  216  can directly access, and is used as the work area of the CPU  216  or another temporary data storage area. 
     The storage unit  247  functions as a temporary storage area and a work memory when the inspection apparatus operates. An inspection apparatus I/F  215  is connected to an inspection unit I/F  231  via a cable. That is, the inspection unit  106  communicates with the inspection apparatus  108  via the inspection apparatus I/F  215  and the inspection unit I/F  231 . 
     An image capturing unit  218  has an image capturing function with, for example, a contact image sensor (to be referred to as a CIS hereinafter), captures a paper sheet passing through the inspection unit, and transmits the captured image to the inspection apparatus  108  via the inspection apparatus I/F  215 . Note that the CIS of the image capturing unit  218  is an example of a sensor, a sensor of another type such as a CCD image sensor may be used, and the image capturing method thereof is not limited. 
     Large Capacity Stacker  107   
     A CPU  221  conducts control and operations of units in the large capacity stacker  107  via a system bus  224 . The CPU  221  conducts execution of programs stored in a storage unit  248  and loaded into a RAM  222 . The RAM  222  is a kind of general volatile storage device that the CPU  221  can directly access, and is used as the work area of the CPU  221  or another temporary data storage area. The storage unit  248  functions as a temporary storage area and a work memory when the inspection apparatus operates. A discharge unit  223  conducts a discharge operation to the main tray and the top tray and monitoring and control of the stacking state on each of the main tray and the top tray. 
     Inspection Apparatus  108   
     A CPU  226  conducts control and operations of units in the inspection apparatus  108  via a system bus  230 . The CPU  226  conducts execution of programs stored in a storage unit  228  and loaded into a RAM  227 . The RAM  227  is a kind of general volatile storage device that the CPU  226  can directly access, and is used as the work area of the CPU  226  or another temporary data storage area. The storage unit  228  functions as a temporary storage area and a work memory when the inspection apparatus operates. 
     A PDL analysis unit  229  loads PDL data such as PDF, PostScript®, and PCL received from the client computer  110  or the information processing apparatus  109 , and executes interpretation processing. A display unit  245  is, for example, a liquid crystal display connected to the inspection apparatus, and accepts a user input to the inspection apparatus or displays the state of the inspection apparatus. The inspection unit I/F  231  is a user interface configured to communicate with the inspection apparatus  108 . 
     Information Processing Apparatus  109   
     A CPU  234  conducts control and operations of units in the information processing apparatus  109  via the system bus  239 . The CPU  234  conducts execution of programs stored in a storage unit  236  and loaded into a RAM  235 . The RAM  235  is a kind of general volatile storage device that the CPU  234  can directly access, and is used as the work area of the CPU  234  or another temporary data storage area. The storage unit  236  functions as a temporary storage area and a work memory when the information processing apparatus operates. A network interface (to be referred to as an NW I/F hereinafter)  237  is connected to NW I/Fs  232  and  240  via a network. The information processing apparatus  109  communicates with the inspection apparatus  108  via the NW I/F  237  and the NW I/F  232 . Also, the information processing apparatus  109  communicates with the client computer  110  via the NW I/F  237  and the NW I/F  240 . 
     Client Computer  110   
     A CPU  243  conducts control and operations of units in the client computer  110  via a system bus  246 . The CPU  243  conducts execution of programs stored in a storage unit  244  and loaded into a RAM  242 . The RAM  242  is a kind of general volatile storage device that the CPU  243  can directly access, and is used as the work area of the CPU  243  or another temporary data storage area. The storage unit  244  functions as a temporary storage area and a work memory when the client computer operates. The client computer  110  is connected to the information processing apparatus  109  via the network interface  240 . 
     Printing Mechanism 
       FIG. 3  is a view showing the internal configuration of the printing apparatus  101 , the inspection unit  106 , and the large capacity stacker  107 . The printing apparatus  101  accepts a user input via the UI panel  102  or displays the state of printing or a device. Various kinds of paper sheets can be stored in the paper feed decks  103  and  104 . Note that a printing paper sheet is not limited to paper and is therefore also called a sheet, but a paper sheet in this specification is a name including a material other than paper. In each paper feed deck, only the uppermost one of the stored paper sheets can be separated and conveyed to a paper sheet conveyance path  305 . To form a color image, development stations  301  to  304  form toner images using color toners of Y, M, C, and K, respectively. The toner image formed here is primarily transferred to an intermediate transfer belt  306 . The intermediate transfer belt  306  rotates clockwise in  FIG. 3 , and the toner image is transferred, at a secondary transfer position  307 , to the paper sheet conveyed from the paper sheet conveyance path  305 . 
     A fixing unit  308  includes a pressurizing roller and a heating roller. When the paper sheet passes between the rollers, the toner is melted and press-bonded, thereby fixing the toner image on the paper sheet. The paper sheet that has left the fixing unit  308  is conveyed to an outlet  312  via a paper sheet conveyance path  309 . If the paper sheet type requires further melting and press-bonding for fixing, the paper sheet is conveyed to a second fixing unit  310  using an upper paper sheet conveyance path after passing through the fixing unit  308 , undergoes additional melting and press-bonding, and is then conveyed to the outlet  312  via a paper sheet conveyance path  311 . If the image forming mode is a double-sided mode, the paper sheet is conveyed to a paper sheet reversing path  313 , reversed in the paper sheet reversing path  313 , and conveyed to a double-sided conveyance path  314 , and image transfer to the second surface is performed at the secondary transfer position  307 . 
     In the inspection unit  106 , a CIS  315  and a CIS  316  are arranged facing each other. The CIS  315  is an image sensor configured to read the upper surface of the paper sheet, and the CIS  316  is an image sensor configured to read the lower surface of the paper sheet. The inspection unit  106  scans the paper sheet using the CISs  315  and  316  at a timing when the paper sheet conveyed to a paper sheet conveyance path  317  reaches a predetermined position. The scanned image is transmitted to the inspection apparatus  108  via the inspection apparatus I/F  215  and the inspection unit I/F  231 . The CPU  226  of the inspection apparatus  108  determines whether the received image includes a defect, and notifies the inspection unit  106  of the determination result via the inspection unit I/F  231  and the inspection apparatus I/F  215 . The CPU  216  of the inspection unit  106  notifies the large capacity stacker  107  of the received determination result via the accessory I/Fs  214  and  220 . 
     The large capacity stacker  107  can stack a large capacity of paper sheets. The large capacity stacker  107  includes a main tray  324  as a tray on which paper sheets are stacked. The paper sheet that has passed through the inspection unit  106  enters the large capacity stacker  107  via a paper sheet conveyance path  319 . From the paper sheet conveyance path  319 , the paper sheet is stacked on the main tray  324  via a paper sheet conveyance path  322 . Also, the large capacity stacker  107  includes a top tray  320  as a discharge tray. The CPU  221  of the large capacity stacker  107  controls the conveyance path, thereby discharging paper sheets in which defects are detected by the inspection apparatus  108  and excess tab paper sheets (also called remaining tabs) to the top tray  320 . To output a paper sheet to the top tray  320 , the paper sheet is conveyed from the paper sheet conveyance path  319  to the top tray  320  via a paper sheet conveyance path  321 . 
     Note that a tab paper sheet is sometimes called a sheet with a tab. More generally, a tab paper sheet is sometime called a cyclic paper sheet (cyclic sheet). The cyclic sheet is not limited to a sheet with a tab. In the cyclic sheets, a plurality of different sheets in a predetermined order form a set of sheets. In a print job, cyclic sheets are used in accordance with the order. If a set of sheets is insufficient for one copy, a new set of sheets can be used. 
     To stack a paper sheet on the main tray  324 , a reversing portion  323  configured to reverse the sheet is used. When stacking a paper sheet on the main tray  324 , the paper sheet is reversed once by the reversing portion  323  such that the direction of the paper sheet that enters becomes the same as the direction of the paper sheet upon stacking. When conveying a paper sheet to the top tray  320 , the sheet is directly discharged without being flipped at the time of stacking. Hence, the reversing operation in the reversing portion  323  is not performed. 
     Registration Operation of Reference Image 
       FIG. 4  is an operation flowchart showing the basic operation of the inspection apparatus  108  when registering a reference image for inspection. 
     In step S 401 , the CPU  226  of the inspection apparatus  108  accepts, via the display unit  245 , an image read start instruction from a user. Next, the process advances to step S 402  to accept, via the display unit  245 , an input of a reference image registration count from the user. Next, the process advances to step S 403 , and the inspection apparatus  108  discriminates whether a notification representing that an inspection target sheet is conveyed from the inspection unit  106  is received via the inspection unit I/F  231  and the inspection apparatus I/F  215 . If the notification is received, the process advances to step S 404 . 
     In step S 404 , the inspection apparatus  108  receives images scanned by the CIS  315  and the CIS  316  from the inspection unit  106  via the inspection unit I/F  231  and the inspection apparatus I/F  215 . 
     Next, in step S 405 , the CPU  226  of the inspection apparatus  108  registers the images received in step S 403  as reference images in the RAM  227 . Note that the images of two surfaces are received per sheet and registered. Each of the reference images to be registered is associated with pieces of information representing a paper sheet number of the image and to which one of the obverse and reverse surfaces the image belongs. Also, identification information for specifying the reference image may be associated. Steps S 403  to S 405  are repeated until the registration of the reference image registration count input in step S 402  is ended. If the registration of the reference image registration count is ended, the process advances to step S 407 , and the CPU  226  ends the image read processing. 
     Basic Operation by Inspection Apparatus 
       FIG. 5  is an operation flowchart showing the basic operation of the inspection apparatus  108  at the time of inspection. In step S 501 , the CPU  226  of the inspection apparatus  108  accepts, via the display unit  245 , an image read start instruction from the user. Next, the process advances to step S 502 , and the inspection apparatus  108  discriminates whether a notification representing that an inspection target sheet is conveyed from the inspection unit  106  is received via the inspection unit I/F  231  and the inspection apparatus I/F  215 . If the notification is received, the process advances to step S 503 . 
     In step S 503 , the inspection apparatus  108  receives, via the inspection unit I/F  231  and the inspection apparatus I/F  215 , images obtained by scanning the both surfaces of a sheet by the CIS  315  and the CIS  316 . Next, in step S 504 , the CPU  226  of the inspection apparatus  108  compares the reference images stored in the RAM  227  with the inspection target scan images received in step S 503 . The reference images are registered in advance in accordance with the procedure described with reference to  FIG. 4  before the start of this procedure and stored in the RAM  227 . In this comparison operation, first, using the characteristic points of the images as reference points for alignment, the image positions of each reference image and a corresponding inspection target scan image are aligned. Next, in the inspection target scan image, the four corners of the paper sheet and the alignment reference points of the scan image are analyzed, thereby detecting whether a position deviation of the image with respect to the paper sheet exists. Next, the density value of the reference image and that of the inspection target scan image are compared on a pixel basis. If a deviation more than an allowable value, that is, a defect is not detected as a result, the inspection result is OK, that is, the inspection target image is determined as a non-defective product. 
     In step S 505 , if the inspection result is OK, the process advances to step S 506 . In step S 506 , the inspection apparatus  108  transmits the inspection result OK to the inspection unit  106  via the inspection unit I/F  231  and the inspection apparatus I/F  215 . According to this, the inspection unit  106  instructs the large capacity stacker  107  to discharge the sheet to the main tray  324 , as shown in  FIG. 6 . In step S 508 , it is determined whether the sheet is the final sheet. Steps S 502  to S 508  are repeated until the inspection of the final sheet is ended. If the inspection of the final sheet is ended, the process advances to step S 509 , and the CPU  226  of the inspection apparatus  108  accepts, via the display unit  245 , an image read end instruction from the user. 
     If it is determined in step S 505  that the inspection result is NG, that is, a defective product, the process advances to step S 507 . In step S 507 , the inspection apparatus  108  transmits the inspection result NG to the inspection unit  106  via the inspection unit I/F  231  and the inspection apparatus I/F  215 . According to this, the inspection unit  106  instructs the large capacity stacker  107  to discharge (purge) the sheet to the tray for NG, that is, the top tray  320 , as shown in  FIG. 6 . Then, steps S 502  to S 508  are repeated until the inspection of the final sheet is ended. From then on, the processing can be ended as in the case of the inspection result OK described above. 
       FIG. 5  shows the outline, and a detailed description of the operation at the time of printing according to this embodiment will be made with reference to  FIGS. 6 to 11 . 
     Operations of Printing Apparatus and Inspection Unit Upon Inspection 
       FIG. 6  is a flowchart of the operations of the printing apparatus  101  and the inspection unit  106  upon inspection. In step S 601 , the printing apparatus  101  accepts a print job from the information processing apparatus  109  under the control of the CPU  201 . 
     The process advances to step S 602 , and the CPU  201  starts printing. Next, the process advances to step S 603 , and the CPU  201  prints an image on a paper sheet (one sheet). The process advances to step S 604 , and the inspection unit  106  notifies the inspection apparatus I/F  231  via the inspection unit I/F that the inspection target sheet is conveyed to the inspection apparatus  108 . Next, in step S 605 , the inspection unit  106  scans, by the CIS  315  and the CIS  316 , the images printed on the conveyed paper sheet. Next, the process advances to step S 606 , and the inspection unit  106  transmits the images scanned in step S 605  to the inspection apparatus  108  via the inspection apparatus I/F  215  and the inspection unit I/F  231 . 
     If the inspection unit  106  receives an inspection result NG from the inspection apparatus  108  via the inspection apparatus I/F  215  and the inspection unit I/F  231  in step S 607 , the process advances to step S 608 . In step S 608 , the CPU  216  of the inspection unit  106  instructs, via the accessory I/Fs  214  and  220 , the large capacity stacker  107  to discharge the paper sheet of the inspection result NG to the tray for NG, for example, the top tray  320 . 
     If the inspection unit  106  does not receive an inspection result NG via the inspection apparatus I/F  215  in step S 607 , the process advances to step S 609 . In step S 609 , the CPU  216  of the inspection unit  106  instructs, via the accessory I/Fs  214  and  220 , the large capacity stacker  107  to discharge the paper sheet to a discharge destination designated in the print job. After that, the process advances to step S 610 , and steps S 603  to S 610  are repeated until the inspection of the final sheet is ended. If the inspection of all sheets is ended, printing is also ended, and therefore, the procedure is ended. 
     Setting of Tab Paper Sheet 
     A remaining tab discharge function that is executed by only the printing apparatus  101  according to the present invention will be described next. The remaining tab discharge function is a function of discharging a tab paper sheet that is not inserted into a print job (not used in a print job) to the outside of the apparatus such that tab paper sheets can correctly be inserted from the first tab paper sheet into the printed product of the next copy. This is because tab paper sheets are provided as a set of a plurality of tab paper sheets whose tab positions are shifted from each other. When generating printed products of a plurality of copies, the positions of tab paper sheets need to match between a plurality of booklets that are products. Hence, when a predetermined number of sheets are used from the start of a set of tab paper sheets, tab paper sheets that are not used in the set of tab paper sheets are discharged, and a new set of tab paper sheets is used from the start for the next booklet. 
       FIG. 7  shows a setting screen  701  for a paper sheet type to be set for a paper feed deck, which is displayed on the UI panel  102 . When a paper feed deck  702  is designated, and “tab paper sheet” is selected as a paper sheet type to be set, a screen  801  configured to select the number of indices of tab paper sheets is displayed ( FIG. 8 ). 
     Here, the number of indices (the number of tabs) of tab paper sheets is information used to calculate the number of remaining tab paper sheets (remaining tabs) when performing remaining tab discharge. For example, “5” is preset as a default value. When the user operates plus and minus keys  802  formed from two keys included in the screen  801 , the value can be changed within the range of, for example, 1 to 10. If the number of tab paper sheets to be used in a text is 3 in a state in which, for example, “5” is set in the setting shown in  FIG. 8 , 5−3=2 is calculated as the number of tab paper sheets to be automatically discharged by remaining tab discharge. A close button  803  is a setting button, and the setting is registered when this button is pressed. A means for setting the number of tabs of tab paper sheets set in the paper feed deck has been described above. 
     Print Processing Including Tab Paper Sheets (Excluding Remaining Tab Paper Sheets from Inspection) 
     An embodiment for excluding only remaining tabs from the inspection target at the time of inspecting a job for a plurality of copies including tab paper sheets will be described next.  FIGS. 9A, 9B and 10  are views divisionally showing the operation flowchart of the printing apparatus  101 . This procedure includes control for excluding remaining tab paper sheets from the inspection target, in addition to the basic printing operation. 
     In step S 1001 , the printing apparatus  101  accepts a print job that is an inspection target from the information processing apparatus  109  under the control of the CPU  201  of the printing apparatus  101 . The process then advances to step S 1002 , and the CPU  201  analyzes the print job. Next, the process advances to step S 1003 , and the CPU  201  discriminates whether the print job uses tab paper sheets. Upon determining in step S 1003  that the print job does not include tab paper sheets, the process advances to step S 1004 , and the CPU  201  performs normal printing. In the normal printing, all printed sheets are included in the inspection target, and the quality of each formed image is inspected. In this case, a defective product is discharged to the top tray of the large capacity stacker  107 , and a non-defective product is discharged to the main tray. The procedure of step S 1004  corresponds to processing from step S 602  in  FIG. 6 . 
     On the other hand, upon determining in step S 1003  that the print job includes tab paper sheets, the process advances to step S 1005 . In step S 1005 , the CPU  201  of the printing apparatus  101  acquires tab count information T representing the number of tab paper sheets of one set, which is set for the paper feed deck on the UI shown in  FIG. 8 . Next, the process advances to step S 1006 , and the CPU  201  discriminates whether the processing target print job is a print job for outputting printed products of a plurality of copies. Upon determining that the print job is a print job for outputting printed products of a plurality of copies, in step S 1007 , the CPU  201  turns on a plural copy flag representing that the print job outputs a plurality of copies. 
     Next, the process advances to step S 1008 , and the CPU  201  clears tab paper sheet count information t representing the number of tab paper sheets to be used in, for example, a text to 0 for the processing target print job. In step S 1009 , the CPU  201  discriminates whether printing of all copies of the print job is completed. If printing of all copies is completed, the processing of the print job is completed. On the other hand, if printing of all copies is not completed, the process advances to step S 1010  to start printing the next copy (also called a booklet). Initially, the next copy is the booklet of the first copy. Next, in step S 1011 , the CPU  201  discriminates whether printing of one copy (booklet) of the print job is completed. If printing of one copy is not completed, in step S 1012 , a sheet is fed under the control of the CPU  201 . The process advances to step S 1013  to discriminate whether a tab paper sheet is fed under the control of the CPU  201 . 
     If a tab paper sheet is fed, the process advances to step S 1014  to add 1 to the tab paper sheet count information t used in the print job. Then, in step S 1015 , the sheet is printed under the control of the CPU  201 . Next, the process advances to step S 1016  to perform inspection processing by the inspection unit  106  to be described later with reference to  FIG. 12 , and then returns to step S 1011 . Upon judging in step S 1013  that a tab paper sheet is not fed, the process advances to step S 1015 . 
     Upon judging in step S 1011  that printing of one copy is completed, the process advances to step S 1017 . In step S 1017 , it is judged under the control of the CPU  201  whether a remaining tab exists. Here, if tab count information T−tab paper sheet count information t=RT is 0, it is judged that no remaining tab exists. If the value is other than 0, it is judged that a remaining tab exists. Note that for a printed product of one copy, tab paper sheets in a plurality of sets, that is, tab paper sheets more than T may be used. Preparing for such a case, the determination of step S 1017  may be done by RT=(tab count information T−tab paper sheet count information t) mod tab count information T. In this case, the value of this equation is the number of remaining tabs. Hence, if this value is 0, it can be determined that no remaining tab exists. Here, mod is an operator for obtaining a remainder, and the remainder to be obtained is a minimum non-negative remainder, that is, a positive value smaller than the number to divide. 
     If no remaining tab exists, the process returns to step S 1008 . If a remaining tab exists, the process advances to step S 1018 , and the CPU  201  discriminates whether the remaining tab count is larger than 0. If the remaining tab count is larger than 0, the process advances to step S 1019 . On the other hand, if the remaining tab count is equal to or smaller than 0, the process branches to step S 1008 . 
     In step S 1019 ,  1  is subtracted from the value of RT. In step S 1020 , the CPU  201  judges whether the plural copy flag is ON. If the plural copy flag is ON, the process advances to step S 1021 , and the CPU  201  notifies, via the accessory I/F  208  and the accessory I/F  214 , the inspection unit  106  that the sheet to be conveyed is a remaining tab. In step S 1022 , the tab paper sheet is fed under the control of the CPU  201 . Next, the process advances to step S 1023 . Step S 1023  is inspection processing by the inspection unit  106  to be described later with reference to  FIGS. 11A and 11B . After that, the process returns to step S 1018 . If the remaining tab count (RT) is 0 in step S 1018 , all remaining tab processes are completed, and the process returns to step S 1008 . 
     By the loop processing of steps S 1018  to S 1023 , all remaining tabs can be discharged from the paper feed tray, and the inspection unit  106  can be notified that the discharged sheets are tab paper sheets. Note that step S 1023  is processing by the inspection unit  106 , and is operated independently of the processing shown in  FIGS. 9 and 10 . However, concerning the remaining tab processing, the inspection unit  106  can know by the notification of step S 1021  that a sheet to be conveyed is a tab paper sheet. 
     Inspection Processing 
       FIGS. 11A and 11B  are operation flowcharts showing inspection processing in the inspection unit  106 .  FIG. 11A  shows processing upon receiving the remaining tab notification in step S 1021  in  FIG. 10 . Upon receiving the remaining tab notification, the inspection unit  106  sets a remaining tab notification flag (step S 1121 ).  FIG. 11B  shows the processing of steps S 1016  and S 1023  in  FIG. 10 . This processing is started by the inspection unit  106  when a sheet is conveyed to the inspection unit  106 . The sheet conveyance to the inspection unit  106  can be known when, for example, a detection signal from a sheet sensor provided near the outlet  312  is received. 
     In step S 1101 , a remaining tab flag is tested, thereby judging whether a remaining tab notification is received. Upon determining that no notification is received, the process advances to step S 1102 . In step S 1102 , the inspection unit  106  notifies, via the inspection apparatus I/F  215  and the inspection unit I/F  231 , the inspection apparatus  108  that the inspection target sheet is conveyed. 
     Next, in step S 1103 , the inspection unit  106  scans images printed on the conveyed paper sheet by the CIS  315  and the CIS  316 . Next, the process advances to step S 1104 , and the inspection unit  106  transmits the images scanned in step S 1104  to the inspection apparatus  108  via the inspection apparatus I/F  215  and the inspection unit I/F  231 . The inspection unit  106  receives the inspection result of the transmitted images from the inspection apparatus  108 , and tests the result in step S 1105 . In step S 1105 , if the inspection result that the inspection unit  106  has received from the inspection apparatus  108  is NG, that is, defective, the process advances to step S 1106 . 
     In step S 1106 , the CPU  216  of the inspection unit  106  instructs, via the accessory I/Fs  214  and  220 , the large capacity stacker  107  to discharge the sheet of the inspection result NG to the tray for NG, for example, the top tray  320 . If the inspection result received by the inspection unit  106  in step S 1105  is not NG, that is, non-defective, the process advances to step S 1107 . In step S 1107 , the CPU  216  of the inspection unit  106  instructs, via the accessory I/Fs  214  and  220 , the large capacity stacker  107  to discharge the paper sheet to a discharge destination designated in the print job. 
     On the other hand, upon determining in step S 1101  that the remaining tab notification is received, the process advances to step S 1108 . In step S 1108 , the inspection unit  106  resets the remaining tab flag. Next, in step S 1109 , the inspection unit  106  scans images printed on the conveyed paper sheet by the CIS  315  and the CIS  316 . Next, the process advances to step S 1110 , and the CPU  216  of the inspection unit  106  discards the scanned images. Next, in step S 1111 , the CPU  216  instructs, via the accessory I/Fs  214  and  220 , the large capacity stacker  107  to discharge the remaining tab paper sheet to the tray for remaining tabs, for example, the top tray  320 . 
     Note that in  FIG. 11B , if a setting is done to automatically transmit a paper sheet conveyance notification to the inspection apparatus  108  when the inspection unit  106  detects sheet conveyance, the setting is canceled in, for example, step S 1108 . After the conveyed sheet is scanned, the setting is done again such that a paper sheet conveyance notification is automatically transmitted. 
     With the above-described configuration and processing, according to this embodiment, when the printing apparatus  101  discharges a remaining tab, the inspection unit  106  is notified of that. Upon receiving the notification, the inspection unit  106  directly conveys the remaining tab to the stacker without setting it to the inspection target. In the stacker, the remaining tab paper sheet is discharged to a tray different from a tray for non-defective sheets and stacked. Hence, the tab paper sheet used in the print job is set to the inspection target. Also, when a remaining tab is discharged every time printing of a printed product of one copy is completed, tab positions can be aligned between booklets when producing printed products of a plurality of copies. 
     Note that a plural copy flag is set in steps S 1006  and S 1007  of  FIG. 9A , and the plural copy flag is tested in step S 1020  of  FIG. 10 . However, all these steps may be omitted. Accordingly, even when printing a single copy, remaining tabs are excluded from the inspection target. Even in this case, remaining tab paper sheets are stacked on the tray for these (for example, the top tray). 
     Second Embodiment 
     In the first embodiment, the inspection unit switches processing upon receiving a remaining tab notification. In the second embodiment, a configuration for switching processing using discharge destination information for tab paper sheets will be described. 
     This embodiment will be described with reference to  FIG. 12  that is an operation flowchart of a printing apparatus  101  and  FIGS. 13A and 13B  that are operation flowcharts showing inspection unit processing in an inspection unit  106 . 
     The differences between  FIGS. 9 and 10  that are the operation flowcharts of the printing apparatus  101  according to the first embodiment and the operation flowcharts of this embodiment are only step S 1020  of  FIG. 10  and step S 1220  of  FIG. 12 . Hence, the processes shown in  FIGS. 9A and 9B  are omitted, and  FIG. 12  is shown as processes in place of  FIG. 10 . A description of parts other than the differences from the first embodiment will be omitted here. 
     Upon determining in step S 1020  of  FIG. 12  that a plural copy flag is on, in step S 1221 , a CPU  201  of the printing apparatus  101  notifies, via an accessory I/F  208  and an accessory I/F  214 , the inspection unit  106  of discharge destination information for a sheet to be conveyed. The discharge destination information indicates, for example, one of two trays provided in a large capacity stacker  107 . In this example, a top tray is designated as the discharge destination of a remaining tab. Note that a tray designated in a print job is the main tray, and a sheet determined as a defective product as the result of inspection is discharged to the top tray. In any case, the discharge destination information notified in step S 1221  is preferably different from the discharge destination designated in the print job. The discharge destinations may be the same. In this case, remaining tabs are discharged to the same tray as non-defective printed products. 
       FIGS. 11A and 11B  that are the operation flowcharts of the inspection unit  106  according to the first embodiment are replaced with  FIGS. 13A and 13B  that are operation flowcharts in this embodiment.  FIG. 13A  shows processing performed when the discharge destination information in step S 1221  of  FIG. 12  is received. Upon receiving the discharge destination information, the inspection unit  106  stores it as the setting of the discharge destination designation (step S 1321 ).  FIG. 13B  shows the processes in step S 1016  of  FIG. 10  and step S 1023  of  FIG. 12 . This processing is started by the inspection unit  106  when a sheet is conveyed to the inspection unit  106 . The sheet conveyance to the inspection unit  106  can be known when, for example, a detection signal from a sheet sensor provided near an outlet  312  is received. 
     In step S 1301 , the inspection unit  106  judges whether the discharge destination designation is the discharge destination designated by the print job. Note that the discharge destination designated by the print job may be notified in advance by, for example, a notification from the printing apparatus  101 , or may be fixed to the main tray or the like. In any case, the discharge destination designated by the print job is set as the initial setting value of the discharge destination designation. The determination of step S 1301  can be implemented by, for example, comparing the current set value of the discharge destination designation with the discharge destination designated by the print job. If the discharge destination designation is the discharge destination designated by the print job in step S 1301 , the process advances to step S 1102 . If the discharge destination designation is not the discharge destination, the process advances to step S 1308 . Processing from step S 1102  is the same as in  FIG. 11B , and a description thereof will be omitted. 
     On the other hand, upon determining in step S 1301  that the discharge destination designation is different from the discharge destination designated by the print job, the process advances to step S 1308 . In step S 1308 , the inspection unit  106  scans images printed on the conveyed paper sheet by a CIS  315  and a CIS  316 . Next, the process advances to step S 1309 , and a CPU  216  of the inspection unit  106  discards the scanned images. Next, in step S 1310 , the CPU  216  instructs, via accessory I/Fs  214  and  220 , the large capacity stacker  107  to discharge the remaining tab paper sheet to the tray corresponding to the discharge destination designation set in  FIG. 13A . Finally, in step S 1311 , the discharge destination designation is returned to the discharge destination designated by the print job. 
     Note that in  FIG. 13B , if a setting is done to automatically transmit a paper sheet conveyance notification to an inspection apparatus  108  when the inspection unit  106  detects sheet conveyance, the setting is canceled in, for example, step S 1308 . After the conveyed sheet is scanned, the setting is done again such that a paper sheet conveyance notification is automatically transmitted. 
     With the above-described configuration and processing, according to this embodiment, when the printing apparatus  101  discharges a remaining tab, the inspection unit  106  is notified of the discharge destination of the remaining tab. Upon receiving the notification, the inspection unit  106  directly conveys the remaining tab whose discharge destination is different from the discharge destination of the print job to the stacker without setting it to the inspection target. In the stacker, the remaining tab paper sheet is discharged to the designated tray and stacked. Hence, the tab paper sheet used in the print job is set to the inspection target. Also, when a remaining tab is discharged every time printing of a printed product of one copy is completed, tab positions can be aligned between booklets when producing printed products of a plurality of copies. 
     Third Embodiment 
     In the first and second embodiments, the remaining tab discharge function is executed only by the printing apparatus  101 . In this embodiment, a configuration using a remaining tab discharge function by an information processing apparatus  109  will be described. The operation of the remaining tab discharge function by the information processing apparatus  109  will be described below. In addition to a text print job including tab paper sheets to be inspected, the information processing apparatus  109  creates another dedicated print job (remaining tab discharge job) for discharging a remaining tab. In the remaining tab discharge job, tab paper sheets are designated as all paper sheets to be used. Next to the print job of the inspection target, the information processing apparatus  109  generates the remaining tab discharge job by designating a discharge destination different from that of the print job of the inspection target and transmits the remaining tab discharge job to a printing apparatus  101 , thereby implementing the remaining tab discharge function. In this embodiment, when printing booklets of a plurality of copies, a print job is created for each booklet, and a remaining tab discharge job is created if necessary. These jobs are executed by the printing apparatus  101 . 
       FIGS. 14A and 14B  are flowcharts of the operations of the printing apparatus  101  and an inspection unit  106  at the time of inspection in a case in which the remaining tab discharge function by the information processing apparatus  109  is used. Since the processes of the apparatuses are shown as one procedure in  FIGS. 14A and 14B  without being separated, the main constituent of each process is explicitly shown to indicate which apparatus executes the process. 
     In step S 1401  of  FIG. 14A , the printing apparatus  101  accepts a print job under the control of a CPU  201 . The process advances to step S 1402 , and the CPU  201  analyzes the print job. Next, the process advances to step S 1403 , and the CPU  201  discriminates whether the print job includes a tab paper sheet. If the print job does not include a tab paper sheet, the process advances to step S 1406 . If the print job includes a tab paper sheet, the process advances to step S 1404 , and the CPU  201  discriminates whether all paper sheets in the print job are tab paper sheets. 
     If all paper sheets are tab paper sheets, the process advances to step S 1405 , and the CPU  201  stores the discharge destination information designated by the print job. Here, the printing apparatus  101  may give an instruction to perform inspection to the inspection unit  106 . Note that if inspection is to be executed unless otherwise specified, this instruction may be absent. In step S 1406 , a sheet is fed under the control of the CPU  201 . Next, the process advances to step S 1407 , and the CPU  201  prints an image on the paper sheet (one sheet). The process advances to step S 1408 , and the inspection unit  106  notifies, via an inspection apparatus I/F  215  and an inspection unit I/F  231 , an inspection apparatus  108  that the inspection target sheet is conveyed. 
     Next, in step S 1409 , the inspection unit  106  scans, by a CIS  315  and a CIS  316 , the images printed on the conveyed paper sheet. Next, the process advances to step S 1410 , and the inspection unit  106  transmits the images scanned in step S 1409  to the inspection apparatus  108 . The inspection apparatus  108  evaluates the received images by comparison with reference images, and transmits the inspection result to the inspection unit  106 . In step S 1411 , it is determined whether the inspection result that the inspection unit  106  has received from the inspection apparatus  108  is NG, that is, defective. If the inspection result is NG, the process advances to step S 1412 . In step S 1412 , a CPU  216  of the inspection unit  106  instructs, via accessory I/Fs  214  and  220 , a large capacity stacker  107  to discharge the paper sheet of the inspection result NG to the tray for NG, for example, a top tray  320 . 
     If the inspection result received by the inspection unit  106  in step S 1411  is not NG, the process advances to step S 1413 . In step S 1413 , the CPU  216  of the inspection unit  106  instructs, via the accessory I/Fs  214  and  220 , the large capacity stacker  107  to discharge the paper sheet to the discharge destination designated by the print job. After that, the process advances to step S 1414 , and steps S 1406  to S 1414  are repeated until the inspection of the final sheet is ended. If the inspection of all sheets is ended, printing is also ended, and therefore, the procedure is ended. 
     If all paper sheets in the print job are tab paper sheets in step S 1404 , the process advances to step S 1415 , and the CPU  201  of the printing apparatus  101  judges whether the discharge destination is different from the discharge destination information stored in step S 1405 . If all paper sheets are tab paper sheets, and the designated discharge destination is different from that of the immediately preceding print job, the job is identified as a remaining tab discharge job. Hence, if the discharge destination is different from the discharge destination of the immediately preceding print job in step S 1415 , the job is judged as a remaining tab discharge job, and the process advances to step S 1416 . In step S 1416 , the CPU  201  clears the discharge destination information. Also, in step S 1416 , the printing apparatus  101  may give an instruction not to perform inspection to the inspection unit  106 . In step S 1417 , the designated sheet (that is, a tab paper sheet) is fed under the control of the CPU  201 . 
     In step S 1419 , the inspection unit  106  that has received the instruction not to perform inspection scans, by the CIS  315  and the CIS  316 , the images printed on the conveyed paper sheet. At this time, the inspection unit  106  does not transmit a paper sheet conveyance notification to the inspection apparatus  108 . Next, the process advances to step S 1420 , and the CPU  216  discards the scanned images. Next, in step S 1421 , the CPU  216  of the inspection unit  106  instructs, via the accessory I/Fs  208  and  214 , the large capacity stacker  107  to discharge the paper sheet to the job-designated discharge destination (for example, the top tray  320 ) of the remaining tab discharge job. After that, the process advances to step S 1423 , and steps S 1417  to S 1423  are repeated until the inspection of the final sheet is ended. If the inspection of all sheets is ended, the procedure is ended. 
     Note that if the instruction not to perform inspection is given to the inspection unit  106  in step S 1416 , and it is determined in step S 1423  that the feeding of all sheets is ended, the printing apparatus  101  may give an instruction to perform inspection to the inspection unit  106 . This can set the next print job to the inspection target. 
     In the above-described way, for a job determined as a remaining tab discharge job, inspection is not performed, and a sheet is discharged to a tray designated for remaining tabs. It is therefore possible to prevent the synchronization between the inspection target sheet and the reference image from being lost, as in the first or second embodiment. In addition, when remaining tab paper sheets are discharged for each print job, tab positions of printed products created by the print jobs can be matched. Furthermore, since a remaining tab discharge job can be designated on a job basis, it is not necessary to notify a remaining tab for each sheet. 
     OTHER EMBODIMENTS 
     Embodiment(s) of the present invention can also be realized by a computer of a system or apparatus that reads out and executes computer executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be referred to more fully as ‘non-transitory computer-readable storage medium’) to perform the functions of one or more of the above-described embodiment(s) and/or that includes one or more circuits (e.g., application specific integrated circuit (ASIC)) for performing the functions of one or more of the above-described embodiment(s), and by a method performed by the computer of the system or apparatus by, for example, reading out and executing the computer executable instructions from the storage medium to perform the functions of one or more of the above-described embodiment(s) and/or controlling the one or more circuits to perform the functions of one or more of the above-described embodiment(s). The computer may comprise one or more processors (e.g., central processing unit (CPU), micro processing unit (MPU)) and may include a network of separate computers or separate processors to read out and execute the computer executable instructions. The computer executable instructions may be provided to the computer, for example, from a network or the storage medium. The storage medium may include, for example, one or more of a hard disk, a random-access memory (RAM), a read only memory (ROM), a storage of distributed computing systems, an optical disk (such as a compact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™), a flash memory device, a memory card, and the like. 
     While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. 
     This application claims the benefit of Japanese Patent Application No. 2021-002391, filed Jan. 8, 2021 which is hereby incorporated by reference herein in its entirety.