Abstract:
An image reproduction apparatus for connection to a network for printing print jobs, includes a printer unit for making images on receiving sheets, a user interface unit provided with operating elements, and a control unit for controlling printing processes and adapted to interrupt an active printing process in response to an interrupt command given via the user interface elements. The control unit is provided with a first module to check whether a print job fed via the network contains a predetermined added data item, and a second module for carrying out an authorization check in respect of any interrupt command input during the performance of a certain print job, if the first module detects the presence of such a predetermined added data item in the print job.

Description:
[0001]    The present application claims, under 35 U.S.C. § 119, the priority benefit of the Netherlands Patent Application No. 1019420 filed Nov. 23, 2001, which is herein fully incorporated by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The invention relates to an apparatus and method for printing print jobs fed from a workstation via a network. In particular, the invention relates to an image reproduction apparatus for connection to a network for printing print jobs, comprising a printer unit for making images on receiving sheets, a user interface unit provided with operating elements, and a control unit for controlling printing processes and adapted to interrupt an active printing process in response to an interrupt command given via the user interface panel.  
           [0004]    2. Discussion of the Background Art  
           [0005]    By means of the operating elements, usually keys on a user interface panel, it is possible to intervene in the processing of print jobs. In many printers, an active print job can be definitively stopped by means of a special stop key on the user interface panel. When this stop key is pressed, the printing process is terminated and the digital image data belonging to the job are either kept locally in the printer for final processing later, or removed directly, depending on the configuration of the specific printer.  
           [0006]    The above interruption function is useful, for example, to enable a large print job which has erroneously been submitted to be stopped or for a print job to be prematurely terminated if the settings are found to be wrong during the printing. This prevents waste of printing papers and toners. The facility to interrupt a current print job, however, may lead to errors or negligent use, so that a print job which really was required or was correct may be lost.  
           [0007]    There are therefore situations in which it is undesirable to interrupt a current print job.  
           [0008]    U.S. Pat. No. 5,321,466 describes an interruption protection for a copying machine in the form of a reserve mode. An operator can set this mode, after which it is only possible to operate the machine, including stopping it, after a code has been input. However, this protection is not coupled to the performance of a copying job, i.e., it is not automatically switched off on completion of the job. In addition, this mode has to be set at the machine. Of course this is not possible when dealing with print jobs fed over a network from a workstation, because the user is generally not present at the machine when the performance of the job starts.  
         SUMMARY OF THE INVENTION  
         [0009]    It is an object of this invention to provide a technique whereby a print job fed via a network can be finished undisturbedly.  
           [0010]    It is another object of this invention to provide an apparatus and method for processing print jobs and interrupt requests, which overcome the problems and limitations associated with the related art.  
           [0011]    To this end, according to an embodiment of the invention, a control unit is provided with a first module to check whether a print job fed via a network contains a predetermined added data item, and a second module for carrying out an authorization check in respect of any interrupt command input during the performance of a certain print job, if the first module detects the presence of such a predetermined added data item in the print job.  
           [0012]    Thus according to an embodiment of the invention, print jobs can be provided with an added data item such as an “attribute” which specifies that a job of this kind once started in the printer may not be interrupted. The control unit recognizes the attribute, if it is present, and in response thereto blocks the interrupt functions that can be operated from the user interface panel using, e.g., the stop key primarily, but possibly also an “interrupt” key, conditionally. Activation of these functions is possible only if an operator gives evidence that he is authorized to do so, for example by inputting a predetermined interruption code.  
           [0013]    The term “interrupt” key in this context means a key which is provided on the user interface panel for a temporary interruption of a current print job so that another job can be carried out. On the completion of the other job, the interrupted job can be resumed. By allowing this “interrupt” function only conditionally, it is easier to prevent errors due to the two parts of the job not being joined up properly or completely.  
           [0014]    According to one embodiment of the invention, the relevant interruption code is specified in the attribute sent with the print job, and is therefore specific to the relevant print job.  
           [0015]    In another embodiment, the control unit is so constructed that it also permits an interruption to a current print job in response to the inputting of a second interruption code pre-programmed in the apparatus, without any relationship with a print job. In this way, a print job can nevertheless be interrupted in the absence of the owner of the job (usually the only one who knows the interruption code transmitted in the attribute). This option is preferably reserved for use by an administrator of the printer. An interrupt facility of this kind not related to the print job can also have the form of an authorizing action other than the inputting of a code, for example the operating of a mechanical lock with a key, or an automatic personal recognition process such as automatic analysis of a fingerprint.  
           [0016]    The invention is also directed to a printer driver, i.e., a computer program for installation in a workstation such as a PC, and for submitting a print job to a printer via a network, wherein it includes a module adapted to give a print job a predetermined added data item which specifies that the relevant print job may not be interrupted when carried out in a printer.  
           [0017]    These and other objects of the present application will become more readily apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]    The invention will now be explained in detail with reference to the accompanying drawings wherein:  
         [0019]    [0019]FIG. 1 is a diagram of an example of a network system with workstations and a printer.  
         [0020]    [0020]FIG. 2 is a diagram of an example of a printer for use according to an embodiment of the invention.  
         [0021]    [0021]FIGS. 3 and 4 are examples of illustrations of the job definition window of a printer driver usable in the present invention.  
         [0022]    FIGS.  5  to  7  are examples of illustrations of a user interface panel and the display contents therein usable in the present invention.  
         [0023]    [0023]FIGS. 8 and 9 are state diagrams of interrupt processes according to an embodiment of the invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]    [0024]FIG. 1 shows a system of workstations (WS) and at least one printer (PR) connected by a local network (N). Workstations, for example, are PC&#39;s and are in each case equipped with a processor unit, a monitor, a keyboard and a mouse or other indicator instrument. The term “printer” includes a digital copying machine in this context. A digital copying machine comprises a scanner, a printer unit, a user interface unit and a connection unit (Digital Access Controller or DAC) for connection to the network and processing print jobs submitted from the workstations. All these components are operatively connected. Users who wish to have a specific data file printed from their workstation can choose for the purpose from a number of printers or even from all the printers in the system.  
         [0025]    As an example, FIG. 2 shows a digital copying machine/printer  1  (PR) suitable for use in the system such as the one shown in FIG. 1. Various parts of the digital copying machine are separately shown diagrammatically. These parts comprise a document feeder  110  for physically handling the documents for copying, a scanner unit  120  for generating digital image data corresponding to an image appearing on a document, a printer unit  130  for making prints of images on image supports in accordance with the digital image data, a supply unit  140 , a finishing and outputting section  150  for image supports, a user interface unit  160 , a control unit  170 , and a network connection unit  171 , all operatively connected.  
         [0026]    The document feeder  110  is provided with an input tray  111  for inputting a stack of documents, a transport mechanism (not shown) for transporting the documents one by one along the scanner unit  120 , and an output tray  112  in which the documents are placed after scanning.  
         [0027]    The scanner unit  120  comprises a flat bed scanner provided with a glass plate on which an original document can be placed, a CCD array and an imaging unit including a movable mirror and lens system for imaging the document on the CCD array. In these conditions, the CCD array generates electrical signals which are converted to digital image data in a known manner.  
         [0028]    The printer unit  130  comprises a known electro-photographic processing stage in which a photo-conductive medium  131  in the form of a belt is charged by means of a corona unit  132  and then exposed by means of an LED array  133  in accordance with digital image data. The charge image thus formed on the medium  131  is developed with toner powder in a developing unit  134 , whereafter the toner image is transferred, in a combined transfer and fixing unit  135 , to a heated rubber belt  136 . On this belt  136  the toner powder softens as a result of the heat of the belt  136  and becomes tacky. It is then transferred and fixed on an image support, e.g., a sheet of paper, fed from the supply unit  140  via a conveyor  137 .  
         [0029]    A supply of image supports (for example, sheets of paper) in different sizes and orientations is available in the supply unit  140 .  
         [0030]    The image supports with the toner image are transported via a conveyor  138  to the finishing and outputting section  150 , which if necessary collates them into sets and staples them and then deposits them in a delivery tray  151 .  
         [0031]    The user interface panel of the user interface unit  160  is provided with a display screen and keys. The user interface unit  160  is connected to the control unit  170  and the network connection unit  171 . The user interface unit  160  also includes a contact lock  161  for switching on and off a special operating mode and a fingerprint scanner  162  for recognition of an operator.  
         [0032]    The control unit of the machine/printer  1  is shown diagrammatically by reference  170 . It comprises a microprocessor, a memory, suitable hardware circuits, modules for controlling the units  110 ,  120 ,  130 ,  140 ,  150  and  160 , and an image processing module for processing the digital image data so that prints of good image quality can be made by the printer unit  130 .  
         [0033]    As already stated, the digital copying machine  1  also includes a network connection unit (Digital Access Controller or DAC)  171  for connection to a local network N, which is diagrammatically shown here in the form of a cable  172 . The network connection unit  171  receives print jobs from the workstations or other locations, converts them to a format that can be processed by the printer unit  130  and in co-operation with the control unit  170  ensures that they are printed on image supports such as sheets of paper.  
         [0034]    A program for sending print jobs to the printer/copying machine is operative in the workstations WS. A program of this kind is termed a “printer driver” and is logically coupled via the network N to one or more printers. When a user wants to send a print job, he calls up the printer driver, for example by clicking an icon intended for the purpose in the application window on his monitor. In response, the printer driver displays a job definition window on the workstation monitor, into which the user can input specifications for the intended print job, such as the number of copies, single or double sided printing and so on.  
         [0035]    An example of a job definition window of this kind is shown in FIG. 3. It comprises various boxes  210 ,  220 ,  230  and  240  with radio buttons and tick boxes for making print settings and a number box  250  for identifying the number of copies desired. Tick box  260  is for setting interruption protection. At the bottom of the job definition window are a number of soft keys, including a key  270  (“OK”), by means of which the submission process for the print job is started.  
         [0036]    When the user has filled in the tick box  260  when entering settings and has clicked on the key  270 , an extra data item is added as an attribute to the data file for printing, and this attribute is recognized by the network connection unit  171  of the printer. The printer then treats the print job as one which cannot be interrupted.  
         [0037]    According to an embodiment of the invention, the added attribute contains an interruption code which is defined by the user when giving the print order. In response to clicking on the “OK” key  270 , the printer driver displays an input window  280  for inputting an interruption code (a figure combination) on the monitor. An example of the input window  280  is shown in FIG. 4.  
         [0038]    After the user has input the interruption code in box  290  of the input window  280 , and has clicked a key  295  (“OK”), the print job is actually sent to the printer.  
         [0039]    As an alternative to inputting an interruption code by the user by means of the inputting window  280 , a fixed code programmed in the intended printer driver can be automatically filled in. An interruption code of this kind is included, for example, in the configuration file of the printer driver and is filled in on installation.  
         [0040]    Print jobs are not necessarily dealt with immediately after receipt by the printer. There is, for example, a category of print jobs which by means of a suitable mechanism in the control unit  170  and network connection unit  171 , are locally stored and not printed after receipt at the printer. In the case of a print job of this kind, which is also termed an interactive print job, the network connection unit  171  extracts the identification data from the print file, and the data are then administered and on command presented for selection on the user interface panel display screen by the control unit  170 . An operator can then select a print job and start it with a start key  61  (FIG. 5). The associated administration of the control unit  170  can be regarded as a set of virtual mailboxes of users. Interactive printing is described, for example, in the European Patent Application EP-A 0 944 239.  
         [0041]    In defining a print job, a user can indicate that the print job is an interactive job, by ticking the box  275  in the job definition window (FIG. 3). If he has also ticked the box  260 , the job is defined as being non-interruptible. If a print job of this kind is started at the machine, the interruption protection automatically comes into operation in the same way as described above in the case of a non-interactive print job.  
         [0042]    A description of the operation of the interrupt protection will now be given, in the case in which an operator of the printer tries to interrupt an active print job.  
         [0043]    As an example, the user interface panel of the user interface unit  160  of the printer  1  is shown in FIG. 5 and comprises a display screen  60 , such as an LCD display, and a number of keys such as a start key  61 , number keys  62 , a correction key  63 , an interrupt key  68 , a stop key  69 , selection keys  64 A- 64 E,  65 A- 65 D, and a key cluster  66 . All these elements are connected to the user interface unit, which in response to operation of the keys transmits signals to the control unit  170  and which also, by way of the user interface unit  160 , controls the display  60  to show possible options and messages to the operator.  
         [0044]    When the copying machine  1  is switched on, the display  60  shows an image formed by a number of vertical columns in each case situated above one of the selection keys  64 A- 64 E. Each column relates to a specific basic function of the machine and shows the various possible settings of that basic function. For example, the column on the extreme left is allocated to the selection between a copying function in which a document is scanned by the scanner and then reproduced, a printer function for interactive printing, in which a print is made of an interactive data file for printing as supplied via the network, and a scanner function in which a document is scanned and a corresponding scan file generated, which can then be retrieved by a workstation. The instantaneously selected setting, in this example the printing function, is indicated by a symbol, such as a dark dot, or by highlighting or by some other means.  
         [0045]    An operator can select a different setting, for example in a cyclic manner, by actuating a selection key. As a result of a change of a setting, the function of one or more of the other selection keys may change, because the old function is no longer relevant and other selection options are required. Other text relating to the new function then appears in the relevant column of the display  60 .  
         [0046]    The selection keys  65 A- 65 D offer the possibility of calling up a different set of functions which cannot be displayed simultaneously due to the restricted dimensions of the display  60 . These are generally functions which are not required for a simple copying or print job, but which offer the operator more options for obtaining particular printing results. In this example, these functions comprise shifting the margin on the print, adding covers and multiple up. The meaning of the keys  65 A- 65 D is indicated in an associated field on the display  60 , e.g., directly beneath each key. When one of the keys is selected, the corresponding set of functions is activated and the make-up of the display  60  is adapted to the associated functions. At the same time, this selection is made clear by shifting or otherwise highlighting the field on the display  60  associated with the actuated key of the group  65 A- 65 D. A special box  67  on the display  60  is intended for indicating the machine status and for any messages to the operator.  
         [0047]    The user interface panel according to an embodiment of the present invention also contains a number display  70  for showing the selected number of copies to be printed, as is generally customary on copying machines.  
         [0048]    If a print job has automatically been started by the control unit  170 , the column above the key  64 A shows that the print function is active and the columns above the keys  64 B and  64 C indicate the settings specified in the print job for single/double sided printing and stapling. These columns are shown in grey to indicate that these settings are at the moment not open to selection or change.  
         [0049]    When an operator selects the copying function by means of the key  64 A (this is shown in FIG. 7), the columns above the keys  64 B and  64 C in the basic setting heading denote: single sided or double sided printing with respect to the original document or the copy sheet, respectively. The column above the key  64 D indicates stapling setting, and the column above the key  64 E indicates the enlargement setting relating to the finishing of the copying job.  
         [0050]    [0050]FIG. 8 is a diagrammatic example of the control process carried out when an operator presses the stop key  69  during a printing process of a print job protected against interruption. In this example, the copying machine/printer  1  states  201 - 204  are shown, including both the state of the user interface unit  160  and the corresponding state of the control unit  170  in relation to the printer unit  130  of the machine (print engine).  
         [0051]    As shown in FIG. 8, the copying machine  1  is at rest in state  201 . The user interface unit  160 , the control unit  170  and the printer unit  130  are in the stand-by state.  
         [0052]    When a print job is received from a workstation, state  202  is entered, in which the control unit  170  first of all detects whether the print job received is a job which is protected from interruption, and it then prints the print job. In this state the user interface unit  160  remains in stand-by (but shows a display as illustrated in FIG. on the user interface panel display).  
         [0053]    A job that is protected against interruption comprises an added data item or an attribute, which characterizes the associated print data file as such. An interruption code required to interrupt the associated job is specified in that attribute. If the print job is finished without further disturbance, the copying machine  1  returns to state  201 .  
         [0054]    If, in state  202 , i.e. during the printing of a (protected) print job, an operator presses or selects the stop key on the user interface panel, the copying machine  1  passes to state  203 . In this state, the user interface unit  160  enters into a forced dialogue with the operator, by displaying on the display a request to key in an interruption code, as shown in FIG. 6. In the meantime, the control unit  170  allows the printer unit  130  to continue with printing the current print job.  
         [0055]    If the operator does not key in an interruption code, or keys in an incorrect interruption code on the user interface panel, the copying machine  1  returns to state  202 , possibly after expiration of a fixed interval of time (“time out”), and the print job is finished.  
         [0056]    If the operator inputs the correct interruption code, the copying machine  1  enters state  204 . In this state the user interface unit  160  displays on the display  60  a message indicating that the current print job is terminated, and the control unit  170  stops the printer unit  130  of the copying machine  1  in such a manner that the copying machine  1  is ready to carry out a new job. The latter implies, inter alia, that all the print sheets already separated are removed from the processing stage. The copying machine  1  then returns to state  201  in which the user interface unit  160  displays on the display  60  a display as shown in FIG. 7.  
         [0057]    In the same way as in FIG. 8, FIG. 9 shows a diagrammatic display of the control process carried out when an operator presses the interrupt key  68  during a printing process of a print job protected from interruption.  
         [0058]    The copying machine  1  is at rest at state  301 . The user interface unit  160 , the control unit  170  and the printer unit  130  are in the stand-by state.  
         [0059]    When a print job is received from a workstation, state  302  is entered, in which the control unit  170  first detects whether the received print job is a job protected against interruption, and then prints the print job, while the user interface unit  170  remains in the stand-by state (although the screen of the user interface panel shows the display as shown in FIG. 5). When the print job has been finished without further disturbance, the copying machine  1  returns to state  301 .  
         [0060]    When, in state  302 , i.e. during the printing of a (protected) print job, an operator presses or selects the interrupt key  68  on the user interface panel, the copying machine  1  enters state  303 . In this state the user interface panel  160  enters into a forced dialogue with the operator by displaying on the display a request to key in an interruption code (see FIG. 6). In the meantime, the control unit  170  allows the printer unit  130  to continue printing the current print job.  
         [0061]    If the operator does not input an interruption code, or if he inputs an incorrect interruption code on the -user interface panel, the copying machine  1  returns to state  302 , possibly after expiration of a fixed interval of time, and the print job is finished.  
         [0062]    If the operator inputs the correct interruption code, the copying machine  1  enters state  304  in which the user interface unit  160  displays on the display  60  a message indicating that the current print job is temporarily stopped, and the control unit  170  stops the printer unit  130  of the machine  1  in-such a manner that the machine  1  is ready for performing a new job. The user interface unit  160  then gives the user the opportunity of inputting settings for the interrupt job via the user interface panel which at that time has the display shown in FIG. 7.  
         [0063]    After making the settings for the interrupt job, the user can press or select the start key  61 , after which the copying machine  1  enters state  305  in which the interrupt job is carried out.  
         [0064]    Once the interrupt job is finished, the copying machine  1  automatically returns to state  304  and awaits the starting of any following interrupt job. If an operator does not start a following interrupt job, then after a specific waiting time (“time out”) the machine  1  automatically returns to state  303  and the interrupted print job re-starts. This also occurs if the operator does not start an interrupt job after entering the interrupt state  304 .  
         [0065]    In the foregoing, the interruption code described is a code which is added in the attribute to a print job protected against interruption. In addition it is also possible to define for the copying machine a fixed code which is not coupled to a specific print job but is operative on all print jobs. This interruption code is required as an aid for a key operator or a printer administrator. A key operator is a privileged operator who administers the printer, carries out minor maintenance, and has special rights. The special interruption code can be programmed by the key operator himself in order to prevent misuse by others. It is also possible to allow interruption via mechanical means such as a lock and key as shown in FIG. 2, element  161 . This key to the lock will preferably be kept and handled by a key operator.  
         [0066]    The printer could also be equipped with any means for recognizing a key operator, after which the interrupt functions blocked in the print job can be unblocked. In this aspect, a fingerprint scanner shown in FIG. 2, element  162 , could be used for this purpose, but other alternative means for this purpose are known to the skilled person and can be used.  
         [0067]    In the foregoing, a copying job has been described as the interrupt job. However, it is within the scope of the invention to treat as interrupt jobs other jobs which are started by means of the machine user interface panel. It may, for example, be an interactive print job as described hereinbefore.  
         [0068]    Although the invention has been explained by reference to the exemplified embodiment described above, it is not restricted thereto. It will immediately be apparent to the skilled person that other embodiments are possible within the scope of the claims.