Patent Publication Number: US-2015077785-A1

Title: Image forming apparatus having secure printing function, control method therefor, and storage medium

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an image forming apparatus, a control method therefor, and a storage medium. 
     2. Description of the Related Art 
     Conventionally, image forming apparatuses have been equipped with functions of performing various types of processing on print jobs, and as one of those functions, there has been known a function of performing printing with security enhanced for print jobs (securely) (see, for example, Japanese Laid-Open Patent Publication (Kokai) No. 2000-76028). 
     This function is generally called secure printing, and for example, print job data with a password assigned thereto is transmitted from a client computer to an image forming apparatus. The transmitted print job data is stored in the image forming apparatus, and a print job waits for execution. In this state, when the password included in the stored print job data is input on an operation screen of the image forming apparatus, the print job is executed. 
     Thus, in secure printing, a print job is executed by a user who executes the print job directly operating the image forming apparatus such as input of a password. As a result, situations in which printed matter is seen by other users, taken by mistake, stolen on purpose, and left can be avoided. 
     However, there may be cases where printing cannot be immediately started or printing cannot be continued and is suspended due to occurrence of an interruption caused by warm-up of the image forming apparatus, various adjustments, or the like immediately before a print job is started or before a print job is completed. Examples of such interruptions include those caused by warm-up of the image forming apparatus, color adjustment, temperature adjustment, cleaning process, return from sleep mode, shortage of consumables such as toner and printing sheets, and retention of other preceding print job. 
     While a user is temporarily away from the image forming apparatus when printing is waiting to be started or suspended because of some problem in the image forming apparatus, printing may be started or resumed. Also, some users may forget he or she executed a print job and may not come back. 
     Namely, if a user leaves the image forming apparatus due to some problem in the image forming apparatus, printed matter may be discharged while he or she is away from the image forming apparatus, and hence effects expected from secure printing cannot be obtained. 
     SUMMARY OF THE INVENTION 
     The present invention provides an image forming apparatus and a control method therefor, which are capable of further improving safety and reliability of a secure printing function, as well as a computer-readable storage medium storing a program for implementing the control method. 
     Accordingly, a first aspect of the present invention provides an image forming apparatus having a secure printing function, comprising a storage unit configured to store print data, which is received from an external apparatus, as print data using the secure printing function, a printing unit configured to execute a printing process on the print data in response to a printing instruction which the image forming apparatus have received from a user, a detection unit configured to detect a print aborting factor during execution of the printing process, a control unit configured to abort the printing process in response to detection of the print aborting factor, and store the print data once again as print data using the secure printing function in the storage unit. 
     Accordingly, a second aspect of the present invention provides a control method for an image forming apparatus having a secure printing function, comprising a storage step of storing print data, which is received from an external apparatus, as print data using the secure printing function, a printing step of executing a printing process on the print data in response to a printing instruction which the image forming apparatus have received from a user, a detection step of detecting a print aborting factor during execution of the printing process, a control step of aborting the printing process in response to detection of the print aborting factor, and storing the print data once again as print data using the secure printing function. 
     Accordingly, a third aspect of the present invention provides a non-transitory computer-readable storage medium storing a program for causing a computer to execute a control method for an image forming apparatus having a secure printing function, the control method comprising a storage step of storing print data, which is received from an external apparatus, as print data using the secure printing function, a printing step of executing a printing process on the print data in response to a printing instruction which the image forming apparatus have received from a user, a detection step of detecting a print aborting factor during execution of the printing process, a control step of aborting the printing process in response to detection of the print aborting factor, and storing the print data once again as print data using the secure printing function. 
     According to the present invention, when a factor that is determined in advance and aborts execution of a printing process occurs during execution of the printing process started by a user performing a printing operation using the image forming apparatus, the printing process is aborted, and print data is stored once again as print data using the secure printing function in the storage section. Therefore, printed matter is never output accidently, and in addition, when printing is to be performed once again, a printing operation is required to be performed one more time. Thus, even if during execution of a print job using the secure printing function, a user who has provided an instruction to execute the print job leaves the image forming apparatus, safety and reliability of the secure printing function can be further improved. 
     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 diagram schematically showing an arrangement of an image forming system including an image forming apparatus according to an embodiment of the present invention. 
         FIG. 2  is a diagram schematically showing an arrangement of the image forming apparatus in  FIG. 1 . 
         FIG. 3  is a view which is useful in explaining operation of a PC and the image forming apparatus in  FIG. 1  when they perform secure printing. 
         FIG. 4  is a view which is useful in explaining operation of the image forming apparatus in  FIG. 1  when it performs secure printing. 
         FIG. 5  is a view showing an operation unit in  FIG. 1  and an exemplary initial setting screen displayed on a display unit of the operation unit. 
         FIG. 6  is a view showing an exemplary execution aborting notification screen displayed on the display unit. 
         FIG. 7  is a flowchart showing a procedure of a printing control process which is carried out by a CPU in  FIG. 1 . 
         FIG. 8  is a flowchart showing a procedure of a secure printing control process which is carried out by the CPU. 
         FIG. 9  is a view showing another exemplary initial setting screen displayed on the display unit. 
         FIG. 10  is a flowchart showing another procedure of a secure printing control process which is carried out by the CPU. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     The present invention will now be described in detail with reference to the drawings showing an embodiment thereof. 
       FIG. 1  is a diagram schematically showing an arrangement of an image forming system  100  including an image forming apparatus  102  according to an embodiment of the present invention. 
     Referring to  FIG. 1 , the image forming system  100  is comprised of the image forming apparatus  102  and a PC  101 , which is an external apparatus, and they are connected to each other via a network  103 . The PC  101  has a printer driver  104  and is connected to the network  103  via a network interface  105 . The external apparatus is not limited to the PC, but may be a tablet terminal, a smartphone, or the like as long as it is a computer having a function of sending print data. 
     The PC  101  transmits print job data (print data), which is data for executing a print job including PDL data described in a page description language (PDL) such as PS (PostScript) or PCL (Printer Control Language), to the image forming apparatus  102  via the printer driver  104  in accordance with a printing instruction from an installed application. The print job data includes printing information such as print settings and an attribute as well as the PDL data and may also include a password or the like. It should be noted that in the present embodiment, an attribute means information indicative of printing using a secure printing function, to be described later (hereafter referred to as “secure printing”), or normal printing. 
     The image forming apparatus  102  includes a network interface  106 , a CPU  107 , a RAM  108 , a storage unit  109 , a reading unit  110 , a print job processing unit  111 , an image forming unit  112 , an operation unit  113 , a sheet feeding unit  114 , and a sheet discharging unit  115 , and they are connected to one another via a bus  116 . 
     The CPU  107  controls the entire image forming apparatus  102 . The RAM  108  stores various programs, which are executed by the CPU  107 , and various data and is also used as a work area for the CPU  107 . The storage unit  109 , which is a nonvolatile storage device such as a hard disk, stores various programs and various data which are to be expanded on the RAM  109 . 
     The reading unit  110  is a scanner, and the image forming unit  112  is a printer. The print job processing unit  111  subjects a print job to image processing in accordance with an attribute of print job data, converts the print job into raster data on a page-by-page basis, and outputs the raster data as print image data printable by the image forming unit  112 . 
     The sheet feeding unit  114  feeds recording media such as print sheets to the image forming unit  112 . Recording media with images printed thereon by the image forming unit  112  are discharged to the sheet feeding unit  115 . The operation unit  113  displays information for a user and receives user operations. The network interface  106  is an interface to the network  103 . 
       FIG. 2  is a diagram schematically showing an arrangement of the image forming apparatus  102  in  FIG. 1 . 
     The image forming apparatus  102  has sheet feeding units A to E and stacking units A to C as well as the constituent elements described above with reference to  FIG. 1 . Recording media fed from the sheet discharging unit  115  are stacked in the stacking units A to C. 
     When printing is started, a recoding medium is fed from any of the sheet feeding units A to E and conveyed to the image forming unit  112  via a sheet conveying path  209 . After an image is formed on the recoding medium by the image forming unit  112 , the recording medium is placed in any of the stacking units A to C by way of the sheet discharging unit  115 . 
       FIG. 3  is a view which is useful in explaining operation of the PC  101  and the image forming apparatus  102  in  FIG. 1  when they perform secure printing. 
     Referring to  FIG. 3 , print job data  305  having an attribute of secure printing includes a password  301  specified by a user and is generated by the printer driver  104  of the PC  101 . 
     Then, the print job data  305  including the password  301 , which is transmitted from the PC  101 , is spooled and stored as print job data of a print job for secure printing in the storage unit  109  of the image forming apparatus  102 . 
     Then, on the operation unit  113  of the image forming apparatus  102 , the user who has sent the print job data  305  selects the print job of the print job data  305  stored in the storage unit  109  and inputs a password. The print job processing unit  111  obtains the password  301  included in the print job data  305  and compares the password input on the operation unit  113  by the user and the password  301  with each other. As a result of the password comparison, when they match, the print job processing unit  111  executes the print job of the print job data  305  and continues a printing process as an ongoing print job  303 . 
     It should be noted that in the description of the present embodiment, a process leading from selection of a print job and input of a correct password on the operation unit  113  by the user to complete discharging of a print job as printed matter  304  from the image forming apparatus  102  is referred to as a print job (printing process). 
     Finally, the print job processing unit  111  discharges the ongoing print job  303  as the printed matter  304 , normally terminates the printing process, and then erases data relating to the print job data  305  temporarily stored in the storage unit  109  and the ongoing print job  303  used as intermediate data. 
     Data erasure, which aims to secure confidentiality, is performed so as to disable operations such as edition, duplication, and browsing of the print job data  305  and re-execution of the print job of the print job data  305  after a printing process is normally terminated. 
     As described above, when the image forming apparatus  102  receives print job data including the password  301  from the PC  101 , it stores the print job data  305 . After that, when the user who has sent the print job data  305  from the PC  101  selects a print job of the print job data  305  and inputs a password for the print job, the image forming apparatus  102  extracts the password  301  included in the print job data  305 . The image forming apparatus  102  then compares the input password and the password  301  extracted from the print job data  305 , and when they match, executes the print job. 
       FIG. 4  is a view which is useful in explaining operation of the image forming apparatus  102  in  FIG. 1  when it performs secure printing. 
     Referring to  FIG. 4 , the print job processing unit  111  obtains the print job data  305  including the password  301  from the storage unit  109  and carries out a print job process  401 . In the print job process  401 , the print job processing unit  111  extracts the password  301  from the print job data  305 , compares the extracted password  301  and the password input by the user on the operation unit  113 , and when they match, executes the print job of the print job data  305  and continues a printing process as the ongoing print job  303 . 
     Here, in the image forming apparatus  102 , because a wide variety of status changes occur during operation, a description will be given of a case where during processing on the ongoing print job  303 , such a print job event  402  as to slow down a printing process on the ongoing print job  303 , for example, some printing preparation time occurs in the image forming apparatus  102 . 
     As described above, examples of the print job event  402  include warm-up of the image forming apparatus  102 , color adjustment, temperature adjustment, cleaning processing, return from sleep mode, shortage of consumable items such as toner and printing sheets, and retention of other preceding print jobs. 
     When the print job event  402  that slows the progress of and suspends the printing process on the ongoing print job  303  occurs, processing on the ongoing print job  303  may be slowed down and suspended. 
     When the print job event  402  occurs to slow down processing on the ongoing print job  303 , the image forming apparatus  102  carries out a print job aborting process  403 . The print job aborting process  403  aborts execution of the ongoing print job  303  and brings the image forming apparatus  102  back to a state before execution of the ongoing print job  303 , that is, a state in which print job data is stored in the storage unit  109 . In the following description, the print job event  402  may be expressed merely as a print aborting factor. 
       FIG. 5  is a view showing the operation unit  113  in  FIG. 1  and an exemplary initial setting screen displayed on a display unit  501  of the operation unit  113 . 
     Referring to  FIG. 5 , the operation unit  113  has the display unit  501 , an entry keypad  502 , a start key  503 , a stop key  504 , and a reset key  505 . 
     The display unit  501 , which is a touch-panel type LCD, is a user interface for a user to perform operation, configuration, and so forth on the image forming apparatus  102 . The entry keypad  502  includes a numeric keypad, a clear key for clearing entries, and so on. The start key  503  is a key for providing instructions to start a print job, a facsimile job, and so on. 
     The stop key  504  is a key for providing an instruction to stop the ongoing print job  303  or the like. The reset key  505  is a key for returning an input value or a setting value to an initial value and causing transition of a currently-displayed screen to an initial screen or a parent screen. 
     An initial setting screen including an initial setting message  506  and selection items  507  to  514  is displayed on the display unit  501 . The initial setting message  506  is a message that prompts the user to select a print aborting factor for which secure printing is to be aborted. The selection items  507  to  514  are items from which the user selects a print aborting factor, and when the user enters a checkmark in a checkbox to select any of the selection items  507  to  514 , the selected item is set as a print aborting factor. 
     Namely, the selection items  507  to  514  are items for the user to selectively set individual factors in a manner consistent with the manner of operation by the user of the image forming apparatus  102  and his/her requirements, and they are not items for fixedly setting all of various factors that slow down the progress of a print job as factors for aborting execution of secure printing. 
     In the present embodiment, it is assumed that the selection items  507  to  510  are a warm-up process, a color adjustment process, a temperature adjustment process, and a cleaning process, respectively. 
     It is also assumed that the selection items  511  to  514  are a return-from-sleep process, a toner shortage error, a sheet shortage error, and a prior printing job process, respectively. These selection items are examples, and accordingly, a selection item may be deleted or another selection item may be added. 
     In the example shown in  FIG. 5 , the warm-up process, the color adjustment process, the temperature adjustment process, the return-from-sleep process, the toner shortage error, and the preceding printing job process are selected as print aborting factors. 
     Thus, when a print aborting factor selected by the user occurs during execution of a print job, the print job aborting process  403  is carried out to bring the image forming apparatus  102  back to a state before execution of the print job, that is, a state in which the print job data  305  is stored in the storage unit  109 . 
       FIG. 6  is a view showing an exemplary execution aborting notification screen displayed on the display unit  501  of the operation unit  113  in  FIG. 1 . 
     Referring to  FIG. 6 , the execution aborting notification screen including a warning message  606  and an OK button  607  are displayed on the display unit  501 . The warning message  606  notifies the user that a print job has been aborted in a case where after the start of a printing process on the print job having an attribute of secure printing, the progress of the print job is slowed down for some reason and execution of the print job is aborted. At this time, a reason why the print job was aborted as well as the warning message  606  may be displayed. 
     When the user depresses the OK button  607 , it is determined that the user has confirmed the warning message  606 , and the display of the warning message  606  exits. 
       FIG. 7  is a flowchart showing a procedure of a printing control process which is carried out by the CPU  107  in  FIG. 1 . 
     First, the print job processing unit  111  obtains the print job data  305  from the PC  101  and stores the obtained print job data  305  in the storage unit  109  (step S 701 ). The print job processing unit  111  then analyzes the print job data  305  to obtain printing information on a print job such as an attribute and print settings (step S 702 ). 
     The print job processing unit  111  then determines whether or not the attribute of the print job data  305  is secure printing (step S 703 ). As a result of the determination in the step S 703 , when the attribute of the print job data  305  is secure printing (YES in the step S 703 ), the print job processing unit  111  stores the print job data  305  as secure print data in the storage unit  109  (step S 708 : storage unit) and terminates the process. 
     On the other hand, as a result of the determination in the step S 703 , when the attribute of the print job data  305  is not secure printing (NO in the step S 703 ), the print job processing unit  111  performs image processing such as RIP on PDL data included in the print job to obtain raster data (step S 704 ). 
     The print job processing unit  111  then transfers the raster data obtained in the step S 704  to the image forming unit  112  and instructs the image forming unit  112  to carry out a printing process, whereby the printing process is carried out to generate the printed matter  304  (step S 705 ). 
     The print job processing unit  111  then provides an instruction to perform post-processing on the generated printed mater  304 . As a result, the printed matter  304  is subjected to specified post-processing while it is being conveyed to any of the stacking units A to C by way of the sheet discharging unit  115  (step S 706 ). 
     Then, in accordance with an instruction from the print job processing unit  111 , the printed matter  304  subjected to the post-processing is discharged to any of the stacking units A to C (step S 707 ), followed by termination of the process. It should be noted that when the attribute of the print job data  305  is not secure printing (when the process proceeds to the step S 707  from NO in the step S 703 ), a normal printing process is carried out. 
       FIG. 8  is a flowchart showing a procedure of a secure printing control process which is carried out by the CPU  107  in  FIG. 1 . 
     The secure printing control process in  FIG. 8  is carried out when the password input on the operation unit  113  by the user who has sent the print job data  305  from the PC  101  and the password  301  included in the print job data  305  stored in the storage unit  109  in the step S 708  in  FIG. 7  are compared with each other, and they match. 
     First, the print job processing unit  111  obtains print aborting factors set on the initial setting screen in  FIG. 5  (step S 801 ). The print job processing unit  111  then determines whether or not any of the print aborting factors obtained in the step S 801  has occurred (step S 802 ). 
     As a result of the determination in the step S 802 , when it is detected that any of the obtained print aborting factors has occurred (YES in the step S 802 ), the print job processing unit  111  aborts the ongoing print job (step S 704 ). 
     The print job processing unit  111  then stores the print job data  305  on the aborted print job once again in the storage unit  109  as print job data for secure printing (step S 815 ). The print job processing unit  111  then displays the warning message  606  in  FIG. 6  on the display unit  501  (step S 816 ) and terminates the process. 
     Reverting to the step S 802 , as a result of the determination in the step S 802 , when none of the print aborting factors obtained in the step S 801  has occurred (NO in the step S 802 ), the print job processing unit  111  analyzes the print job data  305  to obtain printing information such as an attribute of and print settings on the print job (step S 803 ). 
     The print job processing unit  111  then determines whether or not any of the obtained print aborting factors has occurred (step S 804 ). As a result of the determination in the step S 804 , when it is detected that any of the obtained print aborting factors has occurred (YES in the step S 804 ), the process proceeds to the step S 814 . 
     On the other hand, as a result of the determination in the step S 804 , when none of the obtained print aborting factors has occurred (NO in the step S 804 ), the print job processing unit  111  performs image processing such as RIP on PDL data included in the print job to obtain raster data (step S 805 ). 
     The print job processing unit  111  then determines whether or not any of the print aborting factors obtained in the step S 801  has occurred (step S 806 ). As a result of the determination in the step S 806 , when it is detected that any of the obtained print aborting factors has occurred (YES in the step S 806 ), the process proceeds to the step S 814 . 
     On the other hand, as a result of the determination in the step S 806 , when none of the obtained print aborting factors has occurred (NO in the step S 806 ), the print job processing unit  111  transfers the raster data obtained in the step S 805  to the image forming unit  112  and instructs the image forming unit  112  to carry out a printing process. As a result, the printing process is carried out to generate the printed matter  304  (step S 807 ). 
     The print job processing unit  111  then determines whether or not any of the print aborting factors obtained in the step S 801  has occurred (step S 808 ). As a result of the determination in the step S 808 , when it is detected that any of the obtained print aborting factors has occurred (YES in the step S 808 ), the process proceeds to the step S 814 . 
     On the other hand, as a result of the determination in the step S 808 , when none of the obtained print aborting factors has occurred (NO in the step S 808 ), the print job processing unit  111  provides an instruction to perform post-processing on the printed matter  304  generated in the step S 807 . As a result, the printed matter  304  is subjected to specified post-processing while it is being conveyed to any of the stacking units A to C by way of the sheet discharging unit  115  (step S 809 ). 
     The print job processing unit  111  then determines whether or not any of the print aborting factors obtained in the step S 801  has occurred (step S 810 ). As a result of the determination in the step S 810 , when it is detected that any of the obtained print aborting factors has occurred (YES in the step S 810 ), the process proceeds to the step S 814 . 
     On the other hand, as a result of the determination in the step S 810 , when none of the obtained print aborting factors has occurred (NO in the step S 810 ), the print job processing unit  111  provides an instruction to discharge the printed matter  304  subjected to the post-processing to any of the stacking units A to C (step S 811 ). 
     The print job processing unit  111  then determines whether or not any of the print aborting factors obtained in the step S 801  has occurred (step S 812 ). As a result of the determination in the step S 812 , when it is detected that any of the obtained print aborting factors has occurred (YES in the step S 812 ), the process proceeds to the step S 814 . 
     On the other hand, as a result of the determination in the step S 812 , when none of the obtained print aborting factors has occurred (NO in the step S 812 ), the print job processing unit  111  erases data relating to the print job data  305  temporarily stored in the storage unit  109  and the ongoing print job  303  used as intermediate data (step S 813 ) and terminates the process. It should be noted that the steps S 802 , S 804 , S 806 , S 808 , S 810 , and S 812  correspond to a detection unit. 
     In the secure printing control process described above, a print job is immediately aborted when a print aborting factor occurs, but not only a condition that a print aborting factor has occurred but also a condition that a time period determined in advance has elapsed since a print aborting factor occurred may be additionally provided as a condition for aborting a print job. 
     This aims to flexibly set a time period that elapses before a print job is actually aborted according to a usage environment for the image forming apparatus  102  and use and needs of a user. 
       FIG. 9  is a view showing another exemplary initial setting screen displayed on the display unit  501  of the operation unit  113  in  FIG. 1 . 
     Referring to  FIG. 9 , an initial setting message  906 , which prompts the user to select a print aborting factor for execution of secure printing, is displayed on the initial setting screen of the display unit  501  as setting items of the image forming apparatus  102 . Selection items  907  to  909  are also displayed on the display unit  501 . 
     The selection item  907  is an item for immediately aborting a print job after a print aborting factor occurs. The selection item  908  is an item for aborting a print job upon the lapse of a time period determined in advance after occurrence of a print aborting factor. This timed period determined in advance is set with respect to each aborting target factor. 
     The selection item  909  is an item for aborting a print job upon the lapse of a time period determined in advance by the user after occurrence of a print aborting factor. This timed period determined in advance corresponds to a time period entered into the input field  910  by the user, and the user is allowed to set a desired time period. 
     Because the user can select a plurality of conditions for aborting a print job according to his/her mode of usage as shown on the initial setting screen in  FIG. 9 , demands of the user can be satisfied to the maximum extent possible. 
       FIG. 10  is a flowchart showing a procedure of a secure printing control process which is carried out by the CPU  107  in  FIG. 1 . 
     The secure printing control process in  FIG. 10  is carried out when the password input on the operation unit  113  by the user who has sent the print job data  305  from the PC  101  and the password  301  included in the print job data  305  stored in the storage unit  109  are compared with each other, and they match. 
     First, the print job processing unit  111  obtains print aborting factors set on the initial setting screen in  FIG. 5  and a time period determined in advance set on the initial setting screen in  FIG. 9  (step S 1001 ). Specifically, as the time period determined in advance, the print job processing unit  111  obtains “0” when the selection item  907  is selected on the initial setting screen in  FIG. 9 , obtains a time period determined with respect to each factor when the selection item  908  is selected, and obtains a time period input by the user when the selection item  909  is selected. 
     The print job processing unit  111  then determines whether or not any of the print aborting factors obtained in the step S 1001  has occurred, and the time period determined in advance has elapsed since the occurrence of the print aborting factor (step S 1002 ). As a result of the determination in the step S 1002 , when any of the obtained print aborting factors has occurred, and the time period determined in advance has elapsed since the occurrence of the print aborting factor (YES in the step S 1002 ), the print job processing unit  111  aborts the ongoing print job (step S 1014 ). 
     The print job processing unit  111  then stores the print job data  305  on aborted the print job once again as print job data for secure printing in the storage unit  109  (step S 1015 ). The print job processing unit  111  then displays the warning message  606  in  FIG. 6  on the display unit  501  (step S 1016 ) and terminates the process. 
     Reverting to the step S 1002 , as a result of the determination in the step S 1002 , when none of the print aborting factors obtained in the step S 1001  has occurred, or the time period determined in advance has not elapsed since the occurrence of the print aborting factor (NO in the step S 1002 ), the print job processing unit  111  analyzes the print job data  305  to obtain printing information such as an attribute of and print settings on the print job (step S 1003 ). 
     The print job processing unit  111  then determines whether or not any of the print aborting factors obtained in the step S 1001  has occurred, and the time period determined in advance has elapsed since the occurrence of the print aborting factor (step S 1004 ). As a result of the determination in the step S 1004 , when any of the obtained print aborting factors has occurred, and the time period determined in advance has elapsed since the occurrence of the print aborting factor (YES in the step S 1004 ), the process proceeds to the step S 1014 . 
     On the other hand, as a result of the determination in the step S 1004 , when none of the print aborting factors obtained in the step S 1001  has occurred, or the time period determined in advance has not elapsed since the occurrence of the print aborting factor (NO in the step S 1004 ), the print job processing unit  111  performs image processing such as RIP on PDL data included in the print job to obtain raster data (step S 1005 ). 
     The print job processing unit  111  then determines whether or not any of the print aborting factors obtained in the step S 1001  has occurred, and the time period determined in advance has elapsed since the occurrence of the print aborting factor (step S 1006 ). As a result of the determination in the step S 1006 , when any of the obtained print aborting factors has occurred, and the time period determined in advance has elapsed since the occurrence of the print aborting factor (YES in the step S 1006 ), the process proceeds to the step S 1014 . 
     On the other hand, as a result of the determination in the step S 1006 , when none of the obtained print aborting factors has occurred, or the time period determined in advance has not elapsed since the occurrence of the print aborting factor (NO in the step S 1006 ), the print job processing unit  111  transfers the raster data obtained in the step S 1005  to the image forming unit  112  and instructs the image forming unit  112  to carry out a printing process. As a result, the printing process is carried out to generate the printed matter  304  (step S 1007 ). 
     The print job processing unit  111  then determines whether or not any of the print aborting factors obtained in the step S 1001  has occurred, and the time period determined in advance has elapsed since the occurrence of the print aborting factor (step S 1008 ). As a result of the determination in the step S 1008 , when any of the obtained print aborting factors has occurred, and the time period determined in advance has elapsed since the occurrence of the print aborting factor (YES in the step S 1008 ), the process proceeds to the step S 1014 . 
     On the other hand, as a result of the determination in the step S 1008 , when none of the obtained print aborting factors has occurred, or the time period determined in advance has not elapsed since the occurrence of the print aborting factor (NO in the step S 1008 ), the print job processing unit  111  provides an instruction to perform post-processing on the printed mater  304  generated in the step S 1007 . As a result, the printed matter  304  is subjected to specified post-processing while it is being conveyed to any of the stacking units A to C by way of the sheet discharging unit  115  (step S 1009 ). 
     The print job processing unit  111  then determines whether or not any of the print aborting factors obtained in the step S 1001  has occurred, and the time period determined in advance has elapsed since the occurrence of the print aborting factor (step S 1010 ). As a result of the determination in the step S 1010 , when any of the obtained print aborting factors has occurred, and the time period determined in advance has elapsed since the occurrence of the print aborting factor (YES in the step S 1010 ), the process proceeds to the step S 1014 . 
     On the other hand, as a result of the determination in the step S 1010 , when none of the obtained print aborting factors has occurred, or the time period determined in advance has not elapsed since the occurrence of the print aborting factor (NO in the step S 1010 ), the print job processing unit  111  provides an instruction to discharge the printed matter  304  subjected to the post-processing to any of the stacking units A to C (step S 1011 ). 
     The print job processing unit  111  then determines whether or not any of the print aborting factors obtained in the step S 1001  has occurred, and the time period determined in advance has elapsed since the occurrence of the print aborting factor (step S 1012 ). 
     As a result of the determination in the step S 1012 , when any of the obtained print aborting factors has occurred, and the time period determined in advance has elapsed since the occurrence of the print aborting factor (YES in the step S 1012 ), the process proceeds to the step S 1014 . 
     On the other hand, as a result of the determination in the step S 1012 , when none of the obtained print aborting factors has occurred, or the time period determined in advance has not elapsed since the occurrence of the print aborting factor (NO in the step S 1012 ), the print job processing unit  111  erases data relating to the print job data  305  temporarily stored in the storage unit  109  and the ongoing print job  303  used as intermediate data (step S 1013 ) and terminates the process. 
     In the secure printing control process in  FIG. 10 , when a print aborting factor has occurred, and a time period determined in advance has elapsed since the occurrence of the print aborting factor, a printing process is aborted. Moreover, a plurality of references for determining that the progress of a print job has slowed down is provided, and the image forming apparatus  102  can be configured such that the user can select one from the plurality of references via an initial setting screen. As a result, demands of the user for various usage patterns can be satisfied to the maximum extent possible. 
     According to the present embodiment, a print job is started after authentication is performed based on a password, but when a printing process on the print job is suspended due to occurrence of a print aborting factor, the ongoing print job is aborted to bring the image forming apparatus into a standby state which is a state before authentication is performed based on the password. 
     Namely, the image forming apparatus  102  is brought back to a time point when the print job data  305  using secure printing is sent from the PC  101  and stored in the storage unit  109  of the image forming apparatus  102 . Therefore, in order to obtain the printed matter  304  by executing the aborted print job once again, it is necessary for the user to execute the print job once again by performing a printing operation in which he or she inputs the password once more. 
     As a result, printed matter is never accidentally output, and additionally, when printing is performed once again, a printing operation is required to be performed once more. Therefore, safety and reliability of secure printing function can be further improved with consideration given to the risk of the user leaving the image forming apparatus during execution of a print job. 
     OTHER EMBODIMENTS 
     Embodiments of the present invention can also be realized by a computer of a system or apparatus that reads out and executes computer executable instructions recorded on a storage medium (e.g., non-transitory computer-readable storage medium) to perform the functions of one or more of the above-described embodiment(s) of the present invention, 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). The computer may comprise one or more of a central processing unit (CPU), micro processing unit (MPU), or other circuitry, and may include a network of separate computers or separate computer processors. 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. 2013-191662 filed Sep. 17, 2013, which is hereby incorporated by reference herein in its entirety.