Abstract:
A method to increase productivity on digital production press machines following an interrupt job includes sending an expected termination point with continuation data back to a digital front end when the machine terminates the original job, as opposed to waiting until the last schedule sheet exits the machine. In this manner, the digital front end may resubmit the continuation of the original job sooner, thus reducing or eliminating the skipped pitches. Final termination information is determined and compared to the continuous data. If there is a discrepancy, the machine may cycle down and recalculated to ensure job integrity.

Description:
BACKGROUND 
       [0001]    The exemplary embodiments generally relate to xerographic marking devices, and specifically relate to controls and media handling for interrupt jobs. 
         [0002]    Productivity is lost when running a small print job as an interrupt job in the middle of a large job on a digital production press. This is due to the need to have the currently printing job be terminated prior to being able to resubmit that job from the point the machine left off. For example, suppose the digital production press is performing a printing job that is composed of 100 books, each book consisting of 200 sheets, for a total of 20,000 sheets to print. Such a printing job takes a long time to complete. Often, it is desirable to submit a small proof job related to a future printing job, while the large printing job is still running. Once the proof job is printed, editing can be continued on the future job that will later be printed in large quantities. Another example is printing mass mailings, where one large job may be printing, but it is desired to interrupt the large job for small proof jobs without holding up the large job for too long. For printing jobs such as books or mass mailings, even small delays may result in lost profits or lost opportunities. In the fast-paced business world, sometimes it is necessary to interrupt even medium or small jobs with an interrupt job and it can be frustrating if there are any delays while waiting for the interrupt job to be processed. 
       SUMMARY 
       [0003]    Exemplary embodiments include various aspects of a method to increase productivity on a xerographic machine (e.g., a digital production press) following an interrupt job. Currently, if the machine receives a small job interrupt during a job that is already running, the machine terminates the current job and inserts the interrupt job, without skipping any pitches. However, it is not until after the scheduled sheets of the current job have completed printing that the termination information for the current job is sent back to the digital front end with continuation data. Once the digital front end receives the continuation data, the original job is resubmitted and picked up where it left off. One problem is the paper path is now empty and productivity is lost. The solution involves sending an expected termination point with continuation data back to the digital front end when the machine terminates the original job as opposed to waiting until the last schedule sheet exits the machine. In this manner, the digital front end may resubmit the continuation of the original job sooner, thus eliminating the skipped pitches. Final termination information is determined and compared to the continuous data. If there is a discrepancy, the machine may cycle down and recalculates to ensure job integrity. 
         [0004]    One aspect is a method of intermediate job termination. An expected termination point, Y, of a main job is calculated, upon submission of an interrupt job. The main job is resubmitted to print after completion of the interrupt job starting at Y+1. The main job is printed up to Y and the whole interrupt job is printed. Printing of the main job resumes at Y+1 without any pause following the last sheet of the interrupt job. There may be no skipped pitches between the last sheet of the interrupt job and next sheet resuming the main job. A print station may calculate the expected termination point, Y, of the main job and send Y as intermediate continuation data to a digital front end. The print station may also send the actual termination point as final continuation data to the digital front end. The digital front end receives the expected termination point of the main job, before the main job reaches the expected termination point. The print station may compare the actual termination point with the expected termination point and cause a fault to be raised, if they are different. Another aspect is a computer-readable medium storing instructions for performing this method of intermediate job termination. 
         [0005]    Yet another aspect is a xerographic machine, including a feeder, a marker, a stacker, and a print station. At least one feeder feeds sheets onto a paper path, the marker marks images on the sheets on the paper path and the stacker stacks the marked sheets on the paper path. The print station calculates an expected termination point, Y, of a main job, upon submission of a interrupt job. The print station sends Y as intermediate continuation data to a digital front end and sends an actual termination point as final continuation data to the digital front end. The digital front end receives the expected termination point of the main job, before the main job reaches the expected termination point. Resuming printing the main job at Y+1 following a last sheet of the interrupt job occurs with no pause between the last sheet of the interrupt job and the Y+1 sheet of the main job. The print station may compare the actual termination point with the expected termination point and raise a fault message if they differ. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  illustrates a block diagram of an exemplary embodiment of a printing system for performing an exemplary embodiment of method of an intermediate job termination response; 
           [0007]      FIG. 2  illustrates a flow chart of a related art method of handling an interrupt job with lost productivity; and 
           [0008]      FIG. 3  illustrates a flow chart of an exemplary embodiment of method of an intermediate job termination response that allows better productivity. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0009]    While a main job A is printing, a user wants to proof job B, which is one copy or one sheet, and the user submits proof job B as a job interrupt. Exemplary embodiments create an intermediate termination based on the expected point of job completion of a main job when an interrupt job is submitted. One exemplary embodiment is a method of an intermediate job termination response that allows better productivity by enabling the main job to be resubmitted right away after the interrupt job so that printing continues without skipping any pitches. Without this exemplary embodiment, when the above situation occurs, job A is terminated but the machine continues printing sheets that are already scheduled. Proof job B is printed following the last scheduled sheet of job A. As job A&#39;s scheduled sheets are finally completed, the termination information is sent back to the digital front end with continuation data. Once the digital front end receives the continuation data, job A is resubmitted and starts printing. Unfortunately, most of the paper path is then empty, causing lost productivity. This exemplary embodiment reduces or eliminates that lost productivity. When job A is terminated, an expected termination point is used to send a response to the digital front end containing continuation data. The digital front end uses that to continue the job interrupt process by resubmitting job A with the continuation point after proof job B is submitted. This enables proof job B to print without any skipped pitches. Final termination information is calculated once the sheets have printed and is compared to the intermediate continuation data. If the intermediate continuation data is different, the printing system may cycle down and recalculate where to continue to ensure job integrity. 
         [0010]      FIG. 1  illustrates a block diagram of an exemplary embodiment of a printing system for performing an exemplary embodiment of method of an intermediate job termination response. Exemplary embodiments may be performed on many different kinds of xerographic systems, such as printers, copiers, scanners, etc. of which  FIG. 1  illustrates one, namely a digital production press  100 . This digital production press  100  is capable of making over 5,000 letter-size paper sheet impressions per hour with a workflow varying from remote job submission to proofing to printing on demand for color images, graphics, and text on a wide array of stocks. 
         [0011]    The digital production press  100  includes a feeding mechanism (feeder)  102 , a marking engine (marker)  104 , an output module  105  and a stacker  106 . The feeding mechanism  102  includes two feeder modules  110 , each module having a transport mechanism  112  and two paper trays  114 . The marking engine  104  includes a straight paper path with optical guides  116 , several dry ink (toner) containers  118 , a photoreceptor  120 , a single-point image transfer to paper  122 , a fuser  124 , and a duplex path  126 . The stacker  106  includes two stackers  130 , two top trays  132  for press proof and run-time samples, paper path  134 , and an optional document finishing architecture (DFA) for various inline finishing  136  (e.g., booklet maker, square edge, binding, stapling, lamination, and UV coating). 
         [0012]    In this example, the fairly long paper path in the printing system  100  goes from the feeding mechanism  102  through the marking engine  104  through the output module  105  to the stacker  106 . Stock is taken from the feeding mechanism  102  onto the paper path  116  and images are transferred onto the paper below the photoreceptor  120  on the paper path at  122  near the fuser  124 . At this point in the paper path, the paper may continue going straight or loop back around on the duplex path  126 . After the fuser  124 , the post-process interposer  128 , which is sometimes called an inverter, is available to optionally change the orientation of the paper on the paper path. Further down the paper path, paper may move up towards the top tray  132  or down towards one of the stackers  130 , or continue on paper path  134  towards the other stacker  130  or optional finishers  136 . 
         [0013]    The printing system  100  may also include components not shown in  FIG. 1 . Printing system  100  may also include a print station interface platform (PSIP), which is a processor (e.g., a personal computer) coupled to a print engine in the marking engine  104 . The print station interface platform displays any fault messages raised by the print engine and may include diagnostic routines to service the print engine, such as videos for clearing paper jams. The print station interface platform includes a mark facility controller (MFC) that generally controls the overall printing process. The mark facility controller determines which tray the feeding mechanism  102  needs to feed a sheet of paper, informs the marking engine  104  what images to place on the sheet, determines whether the sheet will go through the duplex path for a second image on the other side, determines whether the sheet goes to the top tray  132  or the stacker  130 , or to a finishing device  136 . In addition, the mark facility controller receives information from a digital front end (DFE), which is another processor (e.g., a personal computer) coupled to the print engine. 
         [0014]    The print engine includes the whole image output terminal (IOT) or printing system  100  shown in  FIG. 1 . The print engine and the print station interface platform (PSIP) together form a print station. The print station may also include the mark facility controller (MFC) and any document finishing architecture (DFA)  136 . The print station and the digital front end (DFE) form a system. 
         [0015]    Suppose the printing system  100  of  FIG. 1  is printing sheet  100  of a large job and at this time, a proof or interrupt job starts to print. As sheet  100  goes through the printing system, sheet  100  moves from the feeder  102  to the marker  104  to put the images on the sheet to the fuser  124  to fuse the image onto the sheet and, then, sheet  100  moves out of the marking engine  104  to come to a final destination in the stacker  130 . When sheet  100  comes to rest in the stacker  130 , the stacker  130  sends a complete message to the mark facility controller. Similarly, the feeder  102  and the marker  104  may have reported a status to the mark facility controller. Then, the mark facility controller knows that sheet  100  has finished printing. At this point, the first sheet of the proof job may start printing. First, the digital front end sends a message to the mark facility controller indicating that the large job was successfully interrupted and the last sheet printed was sheet  100 . The digital front end stores this continuation information in a storage device in order to resume later with the next sheet, sheet  101 . 
         [0016]    For printing systems with fairly lengthy paper paths, such as printing system  100 , when a small job of, say one or two sheets is printing, the rest of the paper path is empty, which causes a pause or delay in printing. The printing system  100  is up, i.e., cycled up (i.e., all the motors are still spinning) and ready to print images, but is not able to feed any sheets of paper and print them until the digital front end and the mark facility controller determine which sheet to print next. 
         [0017]      FIG. 2  illustrates a related art method  200  of handling an interrupt job with lost productivity. A large job (main job or job # 1 ) is printing at  202  and, then, the user submits a proof job (interrupt job or job # 2 ) at a time when the large job just happened to have printed up to sheet X at  204 . The large job continues to print sheets X+1 to Y and the proof job starts printing following sheet Y so that there is no interruption in the printing process at  206 . The printing system is following the rhythmic pattern of printing every sheet in each pitch possible. Then, the large job finishes printing the last sheet before starting the proof job, i.e., sheet Y, which comes to rest in the stacker, top tray or finisher at  208 . At this point, the print station (or mark facility controller) determines that sheet Y was the last sheet printed for the large job and sends that information to the digital front end as the continuation data at  210 . Then, the digital front end resubmits the large job with the continuation data so that the printing system is able to resume printing the large job from where it left off, i.e., at sheet Y+1 at  210 . The proof job finishes at  212 . At this point the printing system has a pause or delay in printing sheets at  214 . The duration of the delay is determined by the length of the paper path from the feeder to the stacker for the large job minus the number of sheets in the proof job. If this calculation is negative, then there is no pause. Then, the large job resumes printing at sheet Y+1 at  216 . 
         [0018]      FIG. 3  illustrates an exemplary embodiment of method of an intermediate job termination response that allows better productivity than that of  FIG. 2 . In the same situation, i.e., a large job is printing at  302  and a proof job is submitted at the point where the large job had already printed up to sheet X at  304 , but the method of the intermediate job termination response is different. The print station calculates that sheet Y should be the last sheet printed for the large job (i.e., the expected termination point) and sends that information to the digital front end as intermediate continuation data at  306 . Then, the digital front end resubmits the large job along with the intermediate continuation data to enable the printing system to continue printing the large job from where it left off, i.e., at sheet Y+1 at  306 . Similar to  FIG. 2 , The large job continues to print sheets X+1 to Y and the proof job starts printing following sheet Y so that there is no interruption in the printing process at  308  and the large job finishes printing and physically comes to rest in the stacker, top tray or finisher at  310 . The print station (or mark facility controller) determines that sheet Y was the last sheet printed for the large job and sends that information to the digital front end as final continuation data at  312 . Then, the print station (and/or the digital front end) compares the intermediate and final continuation data at  312 . If they are different, then the printing system performs an action (reconciliation) to ensure job integrity, such as raising a fault message at  314 . The proof job finishes at  316 . The large job resumes printing at sheet Y+1 with no pause between the last sheet of the proof job and sheet Y+1 of the large job. 
         [0019]    In  FIG. 2 , the mark facility controller does not send a message to the digital front end until the last sheet of a completed job hits the stacker  130 , which is too late for the digital front end to have provided information to make sure that the paper path was full. In  FIG. 3 , at the point in time when a proof job is requested, the mark facility controller sends a notification to the digital front end with an estimate of the last sheet of the currently printing large job to end (e.g., sheet  100 ) called an intermediate termination. The last sheet is not confirmed, but is a tentative point where the large job may stop printing to allow the proof job to print. This intermediate termination helps the digital front end plan to send a job, i.e., that if the printing system  100  stops the large job at  100 , then it will resume at sheet  101 . The intermediate termination data is stored by the digital front end. 
         [0020]    In  FIG. 2 , continuation data is sent at the point in time when the sheet is physically done moving through the paper path. Because the paper path is long, if information isn&#39;t available until a sheet physically stops moving in the printing system  100 , then in order to have had another sheet of paper already moving through the paper path, it is necessary to start the new sheet of paper before the point in time when the last sheet of the interrupted job stopped moving. This is why some printing systems have a gap or delay in printing for job interrupts that may cause lost productivity. 
         [0021]    Having the needed information at the right time is important for smooth job interrupt handling in  FIG. 3 . The digital front end needs to plan how to resubmit the large interrupted job before the small proof job completes so that the interrupted job can resume right after the proof job is complete. In  FIG. 2 , this cannot physically happen because the digital front end lacks information about where the large interrupted job stopped printing. This information is lacking because the digital front end does not know the last sheet completed for the large interrupted job until the last sheet physically comes to rest in the system. At that point, it is too late for the digital front end to send job data to the mark facility controller to continue printing. Thus, productivity is lost while the paper path has empty slots. 
         [0022]    To solve the lost productivity problem in  FIG. 3 , a forecast is made for the last sheet of the large interrupted job and this forecast is given to the digital front end so that the digital front end can use this forecast to resubmit the large interrupted job so that the system can get back to the mark facility controller in time to keep the paper path full. 
         [0023]    Internal to the print engine, various messages are sent to control how paper is moving through the paper path. The mark facility controller has to receive information so that it can compile where the large interrupted job left off and then send that information to the digital front end. The digital front end needs to receive information to be able to resubmit the large interrupted job from the point it left off. 
         [0024]    In the sheet  100  example, sheet  100  is scheduled as the last sheet to be printed before the interrupt job is started, As sheet  96  of the large job is printing, suppose there is a paper jam. One embodiment includes a way to detect this occurrence and change the timing of the scheduled job interrupt. In conventional systems, because the mark facility controller does not tell the digital front end where it left off until the mark facility controller actually knows the last sheet was printed, the mark facility controller may negotiate with the digital front end and either continue printing sheets  96 - 100  or interrupt the large job after sheet  95 , when the machine cycles back up after clearing the jam. 
         [0025]    In an exemplary embodiment, options also exist when something happens to stop a large job before the scheduled last sheet. In addition to the intermediate information and continuation data, a final continuation data message may be sent. The final continuation data is sent to maintain job integrity, so that no sheets are repeated or skipped. 
         [0026]    The photoreceptor  120  in the exemplary printing system  100  of  FIG. 1  has eleven pitch modes, or enough room to fit eleven 8½×11 inch pieces of paper in the print path at a time. Each pitch is an opportunity or room available to print a sheet. Pitches may be skipped if, for example, there was no data to print at a particular point in time or the print engine was performing some xerographic adjustments. In this example, the printing system  100  of  FIG. 1  provides 110 opportunities per minute to print a sheet. If, for example, during the course of a minute, only 109 sheets were printed instead of 110, one pitch was skipped. It is possible to hear a skipped pitch during printing as a silence or long pause in the rhythm of printing (e.g., chink, chink, chink, chink, (silence), chink, chink, chink, chink). One advantage of exemplary embodiments is less skipped pitches. 
         [0027]    It will be appreciated that variations of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also, various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art, and are also intended to be encompassed by the following claims.