Abstract:
An image forming apparatus configured to utilize a storage area to store an image includes a receiving unit configured to receive print job data for which a predetermined print method is designated. The predetermined print method is configured to enable a stored image to be printed according to a print instruction given for the image by a user after the image is stored in the storage area. A storing unit is configured to store the generated image of the page into the storage area so that the stored image of the page is printed according to the print instruction, and is configured to, if the generating unit fails to generate an image of a page from the print job data, control an image of another page that the generating unit successfully generates from the print job data so that the image of the another page is not printed.

Description:
BACKGROUND 
       [0001]    1. Field 
         [0002]    The present subject matter relates to an image forming apparatus, an image forming method, and a storage medium. 
         [0003]    2. Description of Related Art 
         [0004]    Conventionally, a page description language (PDL) is commonly used as a format of print jobs transmitted from a client apparatus such as a computer to a printing apparatus. The printing apparatus typically includes a controller that interprets PDL to generate page images on a bitmap memory, and a printer that prints the page images on paper. When the printing apparatus receives a print job from a client apparatus, the controller interprets the print job to generate a page image of each page. The printer successively prints the generated page images. 
         [0005]    The controller includes a module called interpreter which interprets a print job. The interpreter interprets PDL, and page images are generated based on the interpretation result. 
         [0006]    Japanese Laid-Open Patent Application No. 2011-224830 discusses a print method that can print PDL with higher throughput by using limited resources of a printing apparatus. Japanese Laid-Open Patent Application No. 10-177464 discusses a print method that can perform proper error recovery processing even when an error occurs during PDL interpretation. 
         [0007]    The techniques discussed in the foregoing conventional art quit the interpretation process (stop interpreting) and end the job at the point in time when a PDL interpretation error occurs. With a normal print method, pages generated before the occurrence of the PDL interpretation error are output. However, such pages are often discarded because the pages are incomplete as a product. In the case of a print method such as stored printing, page images are stored in a storage area of the printer. Since the unnecessary data is stored in the printing apparatus, a user&#39;s effort is needed to perform deletion processing on the stored data (delete the images of the incomplete pages). 
       SUMMARY 
       [0008]    The present subject matter is directed to a technique which can save a user from performing deletion processing on stored data of already generated pages when a PDL interpretation error occurs in a print method such as stored printing. 
         [0009]    An image forming apparatus according to an aspect of the present subject matter is an image forming apparatus configured to utilize a storage area to store an image. The image forming apparatus includes a receiving unit configured to receive print job data for which a predetermined print method configured to enable a stored image to be printed according to a print instruction given for the image by a user after the image is stored in the storage area is designated as a print method, a generating unit configured to generate an image of a page from the print job data, and a storing unit configured to store the generated image of the page into the storage area so that the stored image of the page is printed according to the print instruction, wherein the storing unit is configured to, if the generating unit fails to generate an image of a page from the print job data, control an image of another page that the generating unit successfully generates from the print job data so that the image of the other page is not printed. 
         [0010]    Further features of the present subject matter will become apparent from the following description of exemplary embodiments with reference to the attached drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  is illustrates an example of a hardware configuration of an image forming apparatus. 
           [0012]      FIGS. 2A and 2B  illustrate an example software configuration of the image forming apparatus. 
           [0013]      FIG. 3  illustrates an example of an error page to which error information is added. 
           [0014]      FIG. 4  is an example flowchart of processing according to a first exemplary embodiment. 
           [0015]      FIG. 5  illustrates an example error page print setting screen. 
           [0016]      FIG. 6  illustrates an example of an output result of normal printing. 
           [0017]      FIG. 7  illustrates an example of an output result of stored printing or RIP post-completion printing. 
           [0018]      FIG. 8 , composed of  FIG. 8A  and  FIG. 8B , is a flowchart illustrating an example of processing according to a second exemplary embodiment. 
           [0019]      FIG. 9  illustrates an example print setting screen of a generated page. 
           [0020]      FIG. 10  illustrates an example page information addition setting screen of an error page. 
           [0021]      FIG. 11  illustrates an example error page when page information is added. 
           [0022]      FIG. 12  illustrates an example error page output method setting screen in the stored printing. 
           [0023]      FIG. 13  illustrates an example job history screen. 
           [0024]      FIG. 14  illustrates an example print job screen in the stored printing. 
       
    
    
     DETAILED DESCRIPTION 
       [0025]    Various exemplary embodiments, features, and aspects of the subject matter will be described in detail below with reference to the drawings. 
         [0026]    An apparatus configuration of an image forming apparatus  100  according to an exemplary embodiment will be described below. 
         [0027]      FIG. 1  is a diagram illustrating an example hardware configuration of the image forming apparatus  100 . 
         [0028]    A central processing unit (CPU)  101  performs control and calculation of various components in the image forming apparatus  100  and execution of programs stored in a storage device via a system bus  108 . The CPU  101  executes programs stored in a hard disk drive (HDD)  104  to implement functions (software configuration) of the image forming apparatus  100  and processing according to flowcharts. 
         [0029]    A random access memory (RAM)  103  is used as a temporary storage area and a work memory during a print operation of the image forming apparatus  100 . The RAM  103  is an example of a storing unit. 
         [0030]    The HDD  104  is a large-capacity storage device and contains various control programs to be executed by the CPU  101 . The HDD  104  is also used as a temporary storage area of data to be processed and as a storage area for stored printing. The HDD  104  is an example of the storing unit. 
         [0031]    A read-only memory (ROM)  106  is a storage device in which a boot processing program of the image forming apparatus  100  is stored. The ROM  106  is an example of the storing unit. 
         [0032]    A network interface (I/F)  102  is an interface for communicating with other apparatuses such as a host computer via an external network. 
         [0033]    An operation unit  109  is a user interface that can display a status of the image forming apparatus  100  and accept an input about a user&#39;s instruction to the image forming apparatus  100 . 
         [0034]    An engine I/F  105  performs communications with and control of a printer engine  107 . 
         [0035]    The printer engine  107  forms an image on a physical sheet surface, for example, by using an electrophotographic technique or an inkjet image forming technique. 
         [0036]    A software configuration of the image forming apparatus  100  according to an exemplary embodiment will be described below. 
         [0037]      FIG. 2A  is a diagram illustrating an example software configuration of the image forming apparatus  100 . 
         [0038]    As described above, each software module is implemented by the CPU  101  loading a program stored in the HDD  104  into the RAM  103  and executing the program. 
         [0039]    A job development unit  201  develops a print job received via the network I/F  102 . 
         [0040]    A PDL interpreter  202  interprets PDL data (hereinafter, referred to as print data) included in the developed print job page by page, and converts the print data into an intermediate data format.  FIG. 2B  illustrates a detailed internal configuration of the PDL interpreter  202 . A job analysis unit  1501  analyzes the PDL data received from the job development unit  201 , and performs processing for passing the PDL to an appropriate interpreter. More specifically, the job analysis unit  1501  analyzes the contents of the PDL data. If a PDL type is determined to be PostScript® (PS), the job analysis unit  1501  passes the PDL data to a PS interpreter  1502 . If the PDL type is determined to be Portable Document Format (PDF) data, the job analysis unit  1501  passes the PDL data to a PDF interpreter  1503 . 
         [0041]    There are PDL data of a page dependent type and PDL data of a page independent type. PS data is PDL data of the page dependent type, which needs to be interpreted in order from the first page. PDF data is PDL data of the page independent type, in which pages can be independently interpreted without interpreting the first page. 
         [0042]    A raster image processor (RIP) processing unit  203  receives the converted intermediate data format and performs RIP processing to generate image data (hereinafter, referred to simply as image) page by page. When using a print method such as stored printing, the RIP processing unit  203  successively stores the images into a storage area  204  page by page. The storage area  204  may be implemented on the RAM  103 . The storage area  204  may be implemented on the HDD  104 . The storage area  204  may be an external storage device connected by the network I/F  102 . In an exemplary embodiment, an image refers to data (page data) generated for each page, such as a bitmap image of a page. 
         [0043]    An image processing unit  205  performs image processing on the generated image. Examples of the image processing include calibration and color conversion. 
         [0044]    A page data transmission unit  206  stores the generated image-processed image into a page spooler  207  and transmits the stored image to the printer engine  107 . The page data transmission unit  206  can directly transmit the image to the printer engine  107 . The page spooler  207  may be implemented on the RAM  103  or the HDD  104 . 
         [0045]    The job development unit  201 , the PDL interpreter  202 , the RIP processing unit  203 , the image processing unit  205 , and the page data transmission unit  206  may be implemented in the image processing apparatus  100  as hardware. A job controller  200  can control the job development unit  201 , the PDL interpreter  202 , the RIP processing unit  203 , the image processing unit  205 , and the page data transmission unit  206  in a centralized manner. 
         [0046]    A PDL error will be described below. 
         [0047]    If an error occurs during interpretation of print data, the PDL interpreter  202  can output a message about an error state. For example, a printer equipped with PostScript® adds error information to an image of an error page (hereinafter, referred to simply as an error page) where the error has occurred, and prints out the resulting error page. More specifically, as illustrated in  FIG. 3 , the printer adds error information including a command causing the error, details of the error, and a stack at that point in time to the error page, and prints out the error page. The PDL error is an example of an interpretation error. 
         [0048]      FIG. 3  illustrates an example error page to which error information is added. 
         [0049]    Stored printing will be described below. 
         [0050]    Methods for outputting a print job other than a normal print method include a stored printing output method. 
         [0051]    When the image forming apparatus  100  performs printing by the normal printing output method (hereinafter, referred to simply as normal printing), the image forming apparatus  100  interprets print data to generate an image. The image forming apparatus  100  then sequentially transmits the image to the page spooler  207  without storing the image in the storage area  204 , and performs printing by using the printer engine  107 . 
         [0052]    When using the stored printing output method (hereinafter, referred to simply as stored printing), the image forming apparatus  100  stores the image generated by interpreting the print data into the storage area  204 . The image forming apparatus  100  does not make a print output in conjunction with such storing. The image forming apparatus  100  can print out the image, for example, based on the user&#39;s print instruction accepted via the operation unit  109 . The image forming apparatus  100  does not delete the image in the storage area  204  even after the first print output. Accordingly, if the image forming apparatus  100  receives the user&#39;s instruction to print out the image for the second and subsequent times, the image forming apparatus  100  prints out the image stored in the storage area  204  again. In the stored printing, the image stored in the storage area  204  is printed out by the printer engine  107  in accordance with the user&#39;s print instruction. 
         [0053]    According to the stored print method, images can be printed not only by the image forming apparatus  100  that stores the images, but also by other image forming apparatuses  100  connected by the network I/F  102 . In such a case, the images are duplicated and printed via the network I/F  102  according to instructions from the other image forming apparatuses  100 . 
         [0054]    The foregoing stored printing is an example of the stored print method. 
         [0055]    RIP post-completion printing will be described below. RIP post-completion printing is another method for outputting a print job. 
         [0056]    When performing printing by a RIP post-completion printing output method (hereinafter, referred to simply as RIP post-completion printing), the image forming apparatus  100  interprets all the print data to generate the images of all the pages. The image forming apparatus  100  then collectively transmits the images of all the pages to the page spooler  207 , and performs printing by using the printer engine  107 . 
         [0057]    The RIP post-completion printing is an output method that takes into account the characteristic that the printer engine  107  is forced to have poor productivity unless a certain number of images or more are stored in the page spooler  207 . The image forming apparatus  100  generates the images of all the pages before transmitting the images to the page spooler  207 , whereby print output can be performed without stopping the printer engine  107 . As employed herein, the productivity refers to, for example, the number of sheets of paper printed per minute (paper per minute). 
         [0058]    Processing of an exemplary embodiment will be described in detail below with reference to  FIG. 4 .  FIG. 4  is an example flowchart of the processing according to an exemplary embodiment. 
         [0059]    In S 300 , the job controller  200  receives a print job from the network I/F  102 , and starts print processing. 
         [0060]    In S 301 , the job controller  200  performs data interpretation of the print job received from the network I/F  102 , and advances the processing to S 302 . 
         [0061]    In S 302 , the job controller  200  generates an image based on the data interpreted in S 301 , and advances the processing to S 303 . In S 302 , if a PDL error is detected during the data interpretation of S 301  (PDL ERROR in S 302 ), the job controller  200  advances the processing to S 310 . 
         [0062]    In S 303 , the job controller  200  determines an output method of the print job. More specifically, the job controller  200  determines the output method based on an output method setting (also referred to as a print method setting; the same applies below) which was input and set by the user via the operation unit  109 . In S 303 , if the output method is determined to be the normal printing (NORMAL PRINTING in S 303 ), the job controller  200  advances the processing to S 304 . In S 303 , if the output method is determined to be the stored printing or the RIP post-completion printing (STORED PRINTING/RIP POST-COMPLETION PRINTING in S 303 ), the job controller  200  advances the processing to S 305 . In other words, the print data is interpreted in page order, and the generated image is successively output according to the determination of the output method. 
         [0063]    The determination of the output method is an example of print method determination processing. The same applies below. 
         [0064]    A case with the normal printing without a PDL error will be described below. 
         [0065]    In S 303 , the job controller  200  determines that the output method is the normal printing (NORMAL PRINTING in S 303 ), and advances the processing to S 304 . 
         [0066]    In S 304 , the job controller  200  transmits the generated image to the page spooler  207  and then to the printer engine  107 , and advances the processing to S 306 . Receiving the image, the printer engine  107  feeds paper and successively performs printing. The job controller  200  repeats the processing of S 301  to S 304  until the received print data reaches the last page. 
         [0067]    In S 306 , the job controller  200  determines whether the print data is the last page. If the print data is determined to be the last page (YES in S 306 ), the job controller  200  advances the processing to S 307 . In S 306 , if the print data is determined not to be the last page (NO in S 306 ), the job controller  200  returns the processing to S 301 . 
         [0068]    In S 307 , the job controller  200  determines whether the output method is the RIP post-completion printing. Since the output method here is the normal printing, the job controller  200  determines that the output method is not the RIP post-completion printing (NO in S 307 ). In S 309 , the job controller  200  ends the print processing. 
         [0069]    A case with the stored printing without a PDL error will be described below. 
         [0070]    In S 303 , the job controller  200  determines that the output method is the stored printing (STORED PRINTING/RIP POST-COMPLETION PRINTING in S 303 ), and advances the processing to S 305 . 
         [0071]    In S 305 , the job controller  200  stores the generated image in the storage area  204 , and advances the processing to S 306 . 
         [0072]    In S 306 , the job controller  200  determines that the print data is the last page (YES in S 306 ), and advances the processing to S 307 . In S 307 , the job controller  200  determines that the output method is not the RIP post-completion printing (NO in S 307 ). In S 309 , the job controller  200  ends the print processing. Since the processing of S 306 , S 307 , and S 309  is described above, a detailed description thereof is omitted here. 
         [0073]    A case with the RIP post-completion printing without a PDL error will be described below. 
         [0074]    In S 303 , the job controller  200  determines that the output method is the RIP post-completion printing (STORED PRINTING/RIP POST-COMPLETION PRINTING in S 303 ), and advances the processing to S 305 . 
         [0075]    In S 305 , the job controller  200  stores the generated image in the storage area  204 , and advances the processing to S 306 . 
         [0076]    In S 306 , the job controller  200  determines that the print data is the last page (YES in S 306 ), and advances the processing to S 307 . In S 307 , the job controller  200  determines that the output method is the RIP post-completion printing (YES in S 307 ), and advances the processing to S 308 . Since the processing of S 306  and S 307  is described above, a detailed description thereof is omitted here. 
         [0077]    In S 308 , the job controller  200  transmits all the image(s) stored in the storage area  204  to the page spooler  207  and then to the printer engine  107 . In S 309 , the job controller  200  ends the print processing. 
         [0078]    Processing when the job controller  200  detects a PDL error in S 302  will be described. In S 302 , the job controller  200  detects a PDL error (PDL ERROR in S 302 ), and advances the processing to S 310  as described above. 
         [0079]    In S 310 , the job controller  200  determines the output method of the print job. If the output method is determined to be the normal printing (NORMAL PRINTING in S 310 ), the job controller  200  advances the processing to S 311 . If the output method is determined to be the stored printing or the RIP post-completion printing (STORED PRINTING/RIP POST-COMPLETION PRINTING in S 310 ), the job controller  200  advances the processing to S 314 . Since the processing of S 310  is similar to that of S 303 , a detailed description thereof is omitted. 
         [0080]    A case with the normal printing with a PDL error will be described below. 
         [0081]    In S 310 , the job controller  200  determines that the output method is the normal printing (NORMAL PRINTING in S 310 ), and advances the processing to S 311 . 
         [0082]    In S 311 , the job controller  200  determines whether to print out an error page. More specifically, the job controller  200  determines whether to print out an error page based on an error page print setting. The error page print setting is input and set into the image forming apparatus  100  by the user&#39;s operation via the operation unit  109 . The print output of the error page is an example of error page print processing. The same applies below. 
         [0083]      FIG. 5  is a diagram illustrating an example of an error page print setting screen displayed on the operation unit  109 . 
         [0084]    If the user wants to print out an error page, the user can input an error page print setting “YES” via the operation unit  109 . If the user does not want to print out an error page, the user can input an error page print setting “NO.” 
         [0085]    In S 311 , if the error page print setting is “YES,” the job controller  200  determines to print out an error page (YES in S 311 ), and advances the processing to S 312 . In S 311 , if the error page print setting is “NO,” the job controller  200  determines not to print out an error page (NO in S 311 ), and then in S 309 , ends the print processing. 
         [0086]    In S 312 , the job controller  200  generates an error page, and advances the processing to S 313 . 
         [0087]    In S 313 , the job controller  200  transmits the error page generated in S 312  to the printer engine  107  for print output. In S 309 , the job controller  200  ends the print processing. 
         [0088]    In other words, if an error occurs during printing by the normal printing, the job controller  200  outputs the image(s) of the page(s) generated before the occurrence of the error. The job controller  200  determines whether to output the image of the page where the error occurred, depending on the error page print setting. 
         [0089]      FIG. 6  illustrates an example of output results when the job controller  200  performs print output processing on a print job in which an error occurred in the third page of the print data. 
         [0090]    Now, a case with the stored printing or RIP post-completion printing with a PDL error will be described. 
         [0091]    In S 310 , the job controller  200  determines that the output method is the stored printing or the RIP post-completion printing (STORED PRINTING/RIP POST-COMPLETION PRINTING in S 310 ), and advances the processing to S 314 . 
         [0092]    In S 314 , the job controller  200  deletes the generated image(s) stored in the storage area  204 , and advances the processing to S 315 . For example, if an error occurs during the interpretation of the third page, the job controller  200  deletes the images of the first and second pages stored in the storage area  204 . 
         [0093]    In S 315 , the job controller  200  determines whether to print out an error page. If the job controller  200  determines to print out the error page (YES in S 315 ), the job controller  200  advances the processing to S 316 . If the job controller  200  determines not to print out the error page (NO in S 315 ), then in S 309 , the job controller  200  ends the print processing. Since the processing of S 315  is similar to that of S 311 , a detailed description thereof is omitted. 
         [0094]    In S 316 , the job controller  200  generates the error page, and advances the processing to S 317 . 
         [0095]    In S 317 , the job controller  200  transmits the error page generated in S 316  to the printer engine  107  for printing. In S 309 , the job controller  200  ends the print processing. 
         [0096]    In other words, if a PDL error occurs during printing by the stored printing or the RIP post-completion printing, the job controller  200  deletes the image(s) of the page(s) generated before the occurrence of the error. The job controller  200  then determines whether to output the error page according to the error page print setting. 
         [0097]      FIG. 7  is a diagram illustrating an example of output results when the job controller  200  outputs an error page and when not in the stored printing or the RIP post-completion printing. 
         [0098]    If a PDL error occurs during the stored printing or the RIP post-completion printing, the job controller  200  can suppress output including the page(s) generated before the occurrence of the error. 
         [0099]    As described above, according to an exemplary embodiment, if a PDL error occurs during printing by the stored printing or the RIP post-completion printing, the job controller  200  can delete the image(s) of the page(s) generated before the occurrence of the PDL error to suppress output. The job controller  200  can output only an error page according to the error page print setting. Consequently, the job controller  200  can save user&#39;s trouble of deleting the page(s) and discarding an output sheet(s). 
         [0100]    In the foregoing exemplary embodiment, the job controller  200  performs the same processing regardless of the PDL type. The job controller  200  may be configured to delete images upon the occurrence of an error during the stored printing or the RIP post-completion printing only if the PDL type is PS. The reason is as follows. PS data is PDL data of the page dependent type so that the job controller  200  cannot interpret pages after the occurrence of an error, and can only obtain some pages before the occurrence of the error. In the case of PDL (here, PDF) data of the page independent type, the job controller  200  can interpret pages after the occurrence of an error, and can use all the pages except the one where the error occurred. 
         [0101]    In the example described in the first exemplary embodiment, if a PDL error occurs during printing by the stored printing or the RIP post-completion printing, the job controller  200  deletes the image(s) of the page(s) generated before the occurrence of the PDL error to suppress output, and outputs only an error page. However, the user sometimes does not want to suppress the output of the image(s) of the page(s) generated before the occurrence of a PDL error, or the user sometimes wants to switch the output destination of the error page. An exemplary embodiment deals with processing in such cases. 
         [0102]    The processing of an exemplary embodiment will be described in detail below with reference to  FIG. 8 . 
         [0103]      FIG. 8  is an example flowchart of the processing according to an exemplary embodiment. 
         [0104]    The processing of S 300  to S 313  in  FIG. 8  is similar to that of S 300  to S 313  in  FIG. 4 . A description thereof is thus omitted. 
         [0105]    In S 310 , the job controller  200  determines that the output method of the print job is the stored printing or the RIP post-completion printing (STORED PRINTING/RIP POST-COMPLETION PRINTING in S 310 ), and advances the processing to S 801 . In S 801 , the job controller  200  determines whether to print out the image(s) of the generated page(s). More specifically, the job controller  200  determines whether to print the generated page(s) based on a generated page print setting. The generated page print setting is set and input into the image forming apparatus  100  by the user&#39;s operation via the operation unit  109 . In such a manner, the user can set into the image forming apparatus  100  whether to print generated pages if an error occurs during the stored printing or the RIP post-completion printing. 
         [0106]      FIG. 9  illustrates an example print setting screen of a generated page displayed on the operation unit  109 . 
         [0107]    If the user wants to print out the images of generated pages, the user can input a generated page print setting “YES” via the operating unit  109 . If the user does not want to print out the images of generated pages, the user can input a generated page print setting “NO.” 
         [0108]    In S 801 , if the generated page print setting is “YES,” the job controller  200  determines to print out the image(s) of the generated page(s) (YES in S 801 ), and advances the processing to S 802 . On the other hand, in S 801 , if the generated page print setting is “NO,” the job controller  200  determines not to print out the image(s) of the generated page(s) (NO in S 801 ), and advances the processing to S 803 . In S 803 , the job controller  200  deletes the image(s) of the generated page(s) stored in the storage area  204 . 
         [0109]    In such a manner, even when a PDL error occurs during the stored printing or the RIP post-completion printing, the job controller  200  can print out the image(s) of the generated page(s) if the user wants to. 
         [0110]    In S 802 , the job controller  200  determines whether to print out an error page. If the job controller  200  determines to print out the error page (YES in S 802 ), the job controller  200  advances the processing to S 804 . If the job controller  200  determines not to print out the error page (NO in S 802 ), the job controller  200  advances the processing to S 812 . Since the processing of S 802  is similar to that of S 311 , a detailed description thereof is omitted. 
         [0111]    In S 812 , the job controller  200  determines the output method of the print job. If the output method is determined to be the stored printing (STORED PRINTING in S 812 ), then in S 309 , the job controller  200  ends the print processing. On the other hand, in S 812 , if the output method is determined to be the RIP post-completion printing (RIP POST-COMPLETION PRINTING in S 812 ), the job controller  200  advances the processing to S 813 . In S 813 , the job controller  200  transmits the image(s) of the generated page(s) stored in the storage area  204  to the printer engine  107  for printing. In S 309 , the job controller  200  ends the print processing. In S 812 , as in S 303  and S 310 , the job controller  200  determines the output method based on the output method setting input and set by the user via the operation unit  109 . 
         [0112]    In S 804 , the job controller  200  generates the error page, and advances the processing to S 805 . 
         [0113]    In S 805 , the job controller  200  determines whether to add page information to the error page. More specifically, the job controller  200  determines whether to add page information to the error page based on an error page page information addition setting. The error page page information addition setting is a setting, which is input into the image forming apparatus  100  by the user&#39;s operation via the operation unit  109 , as to whether to add page information to the error page. 
         [0114]      FIG. 10  illustrates an example of a setting screen of a page information addition setting of an error page displayed on the operation unit  109 . 
         [0115]    In S 805 , if the page information addition setting of the error page is “YES,” the job controller  200  determines to add page information to the error page (YES in S 805 ), and advances the processing to S 806 . In S 805 , if the page information addition setting of the error page is “NO,” the job controller  200  determines not to add page information to the error page (NO in S 805 ), and advances the processing to S 807 . 
         [0116]      FIG. 11  illustrates an example of an error page to which page information is added. 
         [0117]      FIG. 3  illustrates an example of the error page to which page information is not added. A comparison between  FIGS. 3 and 11  shows that the characters “Page  3 ” are displayed as page information in  FIG. 11 . 
         [0118]    If a PDL error occurs, the job controller  200  usually prints out the page(s) generated before the occurrence of the PDL error, as well as an error page. The user can thus easily check the page number of the page causing the PDL error. In an exemplary embodiment, the job controller  200  deletes the image(s) of the page(s) generated before the occurrence of the PDL error during the stored printing or the RIP post-completion printing. In such a case, it is difficult for the user to check the page number where the error page occurred in the data. The job controller  200  then performs the foregoing processing for adding the page information to the error page, whereby the user can easily check the page number of the page causing the PDL error in the data. 
         [0119]    In S 807 , the job controller  200  determines the output method of the print job. If the output method is determined to be the RIP post-completion printing (RIP POST-COMPLETION PRINTING in S 807 ), the job controller  200  advances the processing to S 808 . In S 808 , the job controller  200  transmits all the image(s) of the stored page(s) to the printer engine  107  for printing. In S 309 , the job controller  200  ends the print processing. On the other hand, in S 807 , if the output method is determined to be the stored printing (STORED PRINTING in S 807 ), the job controller  200  advances the processing to S 809 . Since the processing of S 807  is similar to that of S 812 , a detailed description thereof is omitted. 
         [0120]    In S 809 , the job controller  200  determines the output method of the error page in the stored printing. More specifically, the job controller  200  determines the output method of the error page based on an error page output method setting in the stored printing. The error page output method setting in the stored printing is a setting that is input and set into the image forming apparatus  100  by the user&#39;s operation via the operation unit  109  and intended to switch the output method of the error page. 
         [0121]      FIG. 12  is a diagram illustrating an example of an error page output method setting screen in the stored printing displayed on the operation unit  109 . 
         [0122]    In S 809 , if the error page output method setting in the stored printing is to “store in the storage area” (STORE IN STORAGE AREA in S 809 ), the job controller  200  determines to store the error page in the storage area  204 , and advances the processing to S 810 . On the other hand, in S 809 , if the error page output method setting in the stored printing is to “print on a sheet” (PRINT ON SHEET in S 809 ), the job controller  200  determines to print only the error page, and advances the processing to S 811 . 
         [0123]    In S 810 , the job controller  200  stores image(s) of the error page in the storage area  204  like the generated page(s). In S 309 , the job controller  200  ends the print processing. 
         [0124]    In S 811 , the job controller  200  transmits only the error page to the printer engine  107  for printing. In S 309 , the job controller  200  ends the print processing. 
         [0125]    In such a manner, if a PDL error occurs during the stored printing, the job controller  200  can print out only the error page so that the user can see it easily. 
         [0126]    As described above, according to an exemplary embodiment, if a PDL error occurs during the stored printing or the RIP post-completion printing, the job controller  200  switches various settings based on the user&#39;s operations via the operation unit  109 . This can improve the user&#39;s convenience. More specifically, the job controller  200  can switch whether to output the image(s) of the generated page(s), the output method of an error page, and the output form of the error page such as whether to add page information according to the user&#39;s intentions, thereby improving the user&#39;s convenience. 
         [0127]    An exemplary embodiment deals with an exemplary embodiment other than the processing described in the first and second exemplary embodiments. 
         [0128]    The CPU  101  of the image forming apparatus  100  can display the results of print output of processed print jobs on the operation unit  109  as a job history screen. The user can thus check the results of print output of the print jobs executed by the image forming apparatus  100  via the operation unit  109 . 
         [0129]      FIG. 13  is a diagram illustrating an example of the job history screen displayed on the operation unit  109 . 
         [0130]    The job history screen  1300  includes display fields of a job No.  1301 , a job name  1302 , and a result  1303 . The display field of the result  1303  displays “OK” if the print job has been properly processed, and “NG” if an error has occurred. 
         [0131]    The user can thus check the job history screen as to whether an error has occurred. 
         [0132]      FIG. 14  is a diagram illustrating an example of a print job screen in the stored printing, which is displayed on the operation unit  109 . 
         [0133]    A stored printing screen  1400  includes display fields of a Box No.  1401 , a job name  1402 , the number of pages  1403 , and remarks  1404 . The display field of the number of pages  1403  displays the number of stored images. The display field of the remarks  1404  displays a comment when the print job is submitted to the stored printing. For example, if an error occurs during the stored printing, the corresponding display field of the remarks  1404  displays “ERROR PAGE.” The display field of the remarks  1404  may display detailed contents causing the error. The information displayed on the stored printing screen  1400  is an example of image list information in the stored printing. 
         [0134]    In such a manner, the user can easily determine from the print job screen that the stored image is not a normal one but the image of an error page. This improves convenience to the user. 
         [0135]    An exemplary embodiment may be implemented by executing the following processing. The processing includes providing software (program or programs) for implementing the functions of the foregoing exemplary embodiment to a system or an apparatus via a network or various storage media, and reading and executing the program(s) by a computer (or CPU or micro processor unit (MPU)) of the system or apparatus. 
         [0136]    As has been described, according to the foregoing exemplary embodiments, the job controller  200  can save the user&#39;s trouble of having to delete the stored data of already generated pages when a PDL error occurs in a print method such as the stored printing. The job controller  200  can also provide print output convenient to the user by switching various settings based on the user&#39;s operations via the operation unit  109 . 
         [0137]    While the exemplary embodiments of the present subject matter have been described in detail above, the exemplary embodiments are not limited to such specific ones. Various changes and modifications may be made without departing from the gist of an exemplary embodiment of the present subject matter set forth in the claims. 
         [0138]    According to an exemplary embodiment of the present subject matter, it is possible to save the user&#39;s trouble of having to delete the stored data of already generated pages when a PDL interpretation error occurs in a print method such as the stored printing. 
         [0139]    Embodiments of the present subject matter 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 subject matter, 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. 
         [0140]    While the present subject matter has been described with reference to exemplary embodiments, it is to be understood that the subject matter 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. 
         [0141]    This application claims the benefit of Japanese Patent Application No. 2013-040461 filed Mar. 1, 2013, which is hereby incorporated by reference herein in its entirety.