Patent Publication Number: US-2021165611-A1

Title: Printing apparatus, control method for printing apparatus, and storage medium

Description:
The present application is a continuation of U.S. patent application Ser. No. 16/383,271, which was filed on Apr. 12, 2019 and which is a continuation of U.S. patent application Ser. No. 15/205,582, which was filed on Jul. 8, 2016 and which issued as U.S. Pat. No. 10,313,541 on Jun. 4, 2019, which are hereby incorporated by reference herein in their entireties. Further, the present application claims priority to Japanese Patent Application No. 2015-138896, filed Jul. 10, 2015, which is also hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a printing apparatus that receives and prints print data transmitted from an external apparatus. 
     Description of the Related Art 
     Recent introduction of a multi-function peripheral (hereinafter, referred to as an MFP) in a large office has increased a risk of information leakage from a printed product left in the MFP. More specifically, since many office workers now use the MFP to output printing products, there is a risk of exposing confidential information printed on a printed product output by one office worker to another office worker who should not have access to such information. 
     For that reason, an MFP employs a printing system known as hold printing to prevent such information leakage. In the hold printing, a document transmitted from an external apparatus such as a personal computer (PC) is not immediately printed when the document is received, but accumulated on a hard disk in the MFP as a held document. The printing is executed only when the user who has instructed the printing of a document with his or her PC goes to a place where the MFP is installed and executes a print start operation with a touch panel on the MFP. The hold printing described above can not only prevent such information leakage from the printed product mistakenly picked up or left in the MFP, but can also reduce unnecessary printing and the number of document sheets left in the MFP. 
     However, when documents of many users are accumulated on the hard disk in the MFP, a user has to find a document that the user has input from a great number of documents including those input by other users to execute a print start operation for the desired document. As a method for addressing this, Japanese Patent Application Laid-Open No. 2012-254618 discusses a method with which a user can easily find his or her document from the held documents. In Japanese Patent Application Laid-Open No. 2012-254618, a print data control unit of an MFP extracts user identification information from a received document, and manages the information. When a hold printing function is selected, the print data control unit displays a list of the user identification information on an operation unit of the MFP, so that the user can select his or her user identification information from the list. Then, only documents corresponding to the selected user identification information are displayed. The method frees the user from finding the document that the user has input from the great number of documents including those input by other users. 
     As another widely known technique, MFP login permission is given based on user authentication. Examples of such technique include a keyboard authentication method using a user name/password to be input from a touch panel, and an integrated circuit (IC) card authentication method using card information acquired from an IC card through a contactless IC card reader. In either of the authentication methods, verification of the identity of a user is performed using authentication information input by the user through a certain operation. These methods generally involve a login application (or authentication application) including a user table required for matching with authentication information input by the user. 
     Furthermore, a proposed login method involving no user authentication includes a method in which a login application (authentication application) displays a list of user identification information, registered in the user table, on a login screen on a touch panel. With this method, the user can easily log in by simply selecting his or her user identification information on the displayed login screen. In this login method, the user is permitted to log into the MFP without an input of personal information such as a password or card information. In other words, the method involves no strict user authentication, and is inferior to a conventional authentication method in terms of security, but has an advantage in that a login user can be identified through a simple operation. Accordingly, the login method is effective in a case where a user logs into the MFP only through an operation of selecting the user identification information, and a customized function (also referred to as a personalized function) of the MFP corresponding to the login user is provided. 
     Here, a description is given on how the login application displays the list of the user identification information on the login screen in the login method based on the selection of the user identification information described above. 
     For example, in some cases, user identification information of a user who has instructed document input with a PC (hereinafter, referred to as “document input user”) is desirably displayed on the login screen with a priority over other users. For example, it is assumed that the login application may be managing information about a great number of users including only a few document input users. Since the few document input users have instructed document input through PCs, the document input users are likely to soon log into the MFP to perform a print start operation for their documents. The user can more easily select his or her user identification information when only the identification information of such users is displayed on the login screen. In some cases, the user can more easily select his or her user identification when the documents are displayed after sorted by their received date and time. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a method for appropriately displaying user identification information on a login screen. 
     According to an aspect of the present invention, a printing apparatus includes a login control unit, including a user table for registering users permitted to log into the printing apparatus, configured to display a login screen including a list of the users registered in the user table, and to permit a user to log into the printing apparatus when selection of the user is received through the login screen, a printing control unit configured to execute processing for printing print data transmitted from an external apparatus and stored in a storage unit, based on a print start operation performed by the user permitted to log into the printing apparatus, and a management unit configured to manage owner information indicating an owner of the print data stored in the storage unit. The login control unit is configured to acquire the owner information from the management unit, and display the login screen based on the acquired owner information. 
     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 illustrating a system configuration. 
         FIG. 2  is a diagram illustrating a hardware configuration of a multi-function peripheral (MFP). 
         FIG. 3  is a diagram illustrating a software configuration of the MFP. 
         FIGS. 4A, 4B, and 4C  are diagrams each illustrating an example of a login screen. 
         FIGS. 5A and 5B  are diagrams each illustrating an example of a screen for registering or editing a user account. 
         FIG. 6  is a diagram illustrating an example of an application selection screen. 
         FIG. 7  is a diagram illustrating an example of a screen displaying a list of held documents. 
         FIG. 8  is a diagram illustrating a screen for forced hold printing setting. 
         FIG. 9  is a flowchart illustrating processing in the MFP. 
         FIG. 10  is a flowchart illustrating processing in the MFP. 
         FIG. 11  (consisting of  FIGS. 11A and 11B ) is a flowchart illustrating processing in the MFP. 
         FIG. 12  is a diagram illustrating an example of a list of document holding users, managed by a personal print application. 
         FIG. 13  is a diagram illustrating an example of bibliographic information of held documents, managed by the personal print application. 
         FIG. 14  is a diagram illustrating an example of a user list in a user table, managed by a login application. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Exemplary embodiments of the present invention will be described in detail below with reference to drawings. The exemplary embodiments do not limit the scope of the invention according to the appended claims, and not all the combinations of features described in the exemplary embodiments are required for the solution provided by the present invention. 
     A first exemplary embodiment according to the present invention is described. 
     &lt;System Configuration&gt; 
     An example of a system configuration to which the present exemplary embodiment can be applied is described with reference to  FIG. 1 . In a system illustrated in  FIG. 1 , a multi-function peripheral (MFP)  101  and personal computers (PC)  102  are communicably connected via a local area network (LAN)  100 . The PCs  102  each have a function of generating print data written in a page description language through a printer driver and transmitting the print data to the MFP  101 . The MFP  101  has a printing function of receiving and printing the print data transmitted from the PC  102 . The PC  102  is an example of an external apparatus, and the MFP  101  is an example of a printing apparatus. 
     The MFP  101  has a hold printing function to prevent information leakage from a print document left in the MFP  101 . The hold printing function is a function with which print data transmitted from the PC  102  is not immediately printed at the point of reception, but is accumulated on a hard disk in the MFP  101  as a held document. Accordingly, after the user instructs printing of a document with a PC, the printing is executed only when the user goes to a place where the MFP  101  is installed and executes a printing start operation through an operation unit on the MFP  101 . The hold printing function can not only prevent information leakage from a printed product mistakenly picked up or left in the MFP  101 , but can also reduce unnecessary printing and document sheets left in the MFP  101 . 
     &lt;Hardware Configuration&gt; 
       FIG. 2  is a diagram illustrating a hardware configuration of the MFP  101 . The MFP  101  includes a controller unit  216 , a printer unit  212 , a scanner unit  214 , an operation unit  208 , and a card reader  219 . The controller unit  216  is connected to the LAN  100  and a public line (e.g., Public Switched Telephone Network (PSTN) or Integrated Services Digital Network (ISDN)), and receives and outputs image data and device information. 
     The printer unit  212  prints raster image data on a sheet through electrophotography using a photosensitive drum and a photosensitive belt, or inkjet printing in which an image is directly printed on the sheet with ink discharged from a micro nozzle array. The printer unit  212  starts printing processing under an instruction from a central processing unit (CPU)  201 . The printer unit  212  includes a plurality of sheet feeding stages so that different sheet sizes and different sheet orientations can be selected. The printer unit  212  further has a finishing function and the finishing mechanism is referred to as a finisher and the like, as an additional function. The finishing mechanism includes a mechanism that sorts printed products into sets of copies, staples the printed products, and folds the printed products. 
     The scanner unit  214  is a device that irradiates an image on a sheet of document with light, and scans the image with a charge-coupled device (CCD) line sensor, so that the image is converted into an electrical signal as raster image data. The scanner unit  214  performs an operation of reading the sheet of document under the control performed by the CPU  201 , in response to a reading start instruction from the user issued through the operation unit  208 . 
     The operation unit  208  includes a liquid crystal display (LCD) on which a touch panel sheet is attached, and displays an operation screen. When a key on the displayed screen is pressed (touched with a finger), the operation unit  208  informs the CPU  201  of information about the pressed position through an operation unit interface  207 . The operation unit  208  includes various operation keys (hardware keys) examples of which include a start key, a stop key, an identification (ID) key, and a reset key. 
     The card reader  219  is a device that acquires card information from a contactless IC card. The card reader  219  reads the card information stored in the IC card under the control performed by the CPU  201 , and notifies the CPU  201  of the read card information, through an external interface  218  in the controller unit  216 . Examples of the IC card include FeliCa (conforming to ISO/IEC 15408) (registered trademark) from Sony Corporation and MIFARE (conforming to ISO/IEC 14443) (registered trademark) from NXP Semiconductors N.V. 
     The controller unit  216  is a device that controls the MFP  101 . The controller unit  216  includes the CPU  201 , a random access memory (RAM)  202 , a read only memory (ROM)  203 , a hard disk drive (HDD)  204 , a network interface  205 , a modem  206 , the operation unit interface  207 , an image bus interface  220 , and the external interface  218  that are connected to a system bus  209 . The controller unit  216  includes a raster image processor  210 , a printer interface  211 , a scanner interface  213 , and an image processor  217  that are connected to an image bus  215  that transfers image data at a high speed. 
     The CPU  201  is a processor that controls the MFP  101 . The RAM  202  is a system network memory for the CPU  201  operating, and also serves as a program memory for storing a program and an image memory for temporarily storing image data. The ROM  203  stores an activation program and various control programs for the system. The HDD  204  stores various programs for controlling the system, image data, user information for user authentication/identification, and the like. 
     The operation unit interface  207  is an interface unit for the operation unit  208 , and outputs data to be displayed to the operation unit  208 . The operation unit interface  207  transmits information, input from the user through the operation unit  208 , to the CPU  201 . 
     The network interface  205  is connected to the LAN  100 , and outputs and receives data to and from the PCs  102  and another external apparatus. The modem  206  is connected to a public line such as PSTN, and performs data input/output such as FAX transmission/reception. 
     The external interface  218  receives an external input from a universal serial bus (USB), an IEEE 1394 compliant bus, a printer port, recommended standard (RS)-232C based serial port, and the like. In the present exemplary embodiment, the card reader  219  is connected to the external interface  218 . Through the external interface  218 , the CPU  201  can control reading of information from an IC card by the card reader  219  and can obtain the information read from the IC card. 
     The image bus interface  220  is a bus bridge which connects the system bus  209  with the image bus  215  and converts a data structure. The image bus  215  is a peripheral component interconnect (PCI) bus or an IEEE 1394 compliant bus. The raster image processor  210  rasterizes print data into a bit map image. The printer interface  211  connects the printer unit  212  with the controller unit  216 , and performs synchronous/asynchronous conversion on image data. The scanner interface  213  connects the scanner unit  214  with the controller unit  216 , and performs synchronous/asynchronous conversion on image data. The image processor  217 , for example, corrects, processes, and edits input image data to perform correction, resolution conversion, and the like on the printer, for print output image data. The image processor  217  rotates image data, and executes compression/decompression processing using Joint Photographic Experts Group (JPEG) for multivalued image data and Joint Bi-level Image Experts Group (JBIG), Modified Modified READ (MMR), Modified Huffman (MH), and the like for bi-level image data. 
     The MFP  101  with the configuration described above can accumulate print data transmitted from the PC  102  through the LAN  100  as a held document, and print out the document in response to a print start instruction from the user. 
     &lt;Software Configuration&gt; 
       FIG. 3  is a block diagram illustrating a software configuration of the MFP  101 . The MFP  101  includes a copy application  301 , a transmission application  302 , and a personal print application  310 . 
     The copy application  301  is an application for controlling the scanner unit  214  and the printer unit  212  to execute copying. The transmission application  302  is an application for controlling the scanner unit  214 , the network interface  205 , and the modem  206  to transmit an image of a scanned document to an external apparatus by email, FAX, and the like. The personal print application  310  is an application for accumulating print data, transmitted from the PC  102 , in the HDD  204  as a held document, displaying a list of held documents of logged in users, and executing processing for printing a document selected from the list. A login application  320  is an application for executing processing related to user authentication and login. 
     In the present exemplary embodiment, two especially important applications are described in detail. The two applications are the personal print application  310 , which is an example of a print control unit, and the login application  320 , which is an example of a login control unit. 
     First of all, the personal print application  310  will be described. The personal print application  310  includes a print data storage unit  312 , a bibliographic information storage unit  313 , and a document holding user management unit  314 . The print data storage unit  312  performs control so that a document transmitted from the PC  102  is stored in the HDD  204 . The bibliographic information storage unit  313  performs control so that print settings and an owner name (owner information), described in the print data transmitted from the PC  102 , are extracted and stored in the HDD  204  as bibliographic information illustrated in  FIG. 13 . The document holding user management unit  314  manages the owner name, extracted from the print data transmitted from the PC  102 , as information for identifying a user for which a held document is held (hereinafter, referred to as document holding user information). As illustrated in  FIG. 12 , pieces of the document holding user information are managed in a state where pieces of the document holding user information are sorted in a reverse chronological order (descending order) of the received date and time of the print data. The document holding user information is deleted in response to the deletion of the print data caused by completion of the printing or a deletion instruction from the user. 
     Here, it is especially important that the document holding user information is managed not by the login application  320 , but by the personal print application  310 . The document holding user information is dynamic information that is frequently updated by input and deletion of documents. If such dynamic information is managed by the login application  320 , the personal print application  310  needs to frequently issue an update notification to the login application  320 . Thus, the present exemplary embodiment employs the configuration where the personal print application  310  manages the document holding user information. 
     Next, the login application  320  will be described. The login application  320  includes an authentication method setting unit  321 , a user management unit  322 , and a login screen display unit  324 . The authentication method setting unit  321  sets an authentication method. In the present exemplary embodiment, three authentication methods are described, namely, a card authentication method, a keyboard authentication method, and an icon selection method. In the card authentication method, an integrated circuit (IC) card is used. In the keyboard authentication method, a user name and a password to be input by the user through a keyboard of the operation unit  208  are used. In the icon selection method, login is permitted through selection of a user icon displayed on an icon selection screen. A biometric authentication method, in which an individual is identified based on a human physical feature such as vein, is another available authentication method but will not be described herein. The icon selection method is especially important in the present exemplary embodiment. 
     In the icon selection method, the login application  320  displays a list of user names, registered in a user table, and icon images corresponding to respective user names, on the login screen of the operation unit  208 . In this method, the user can easily log in by simply selecting icon corresponding to the user on the login screen. In the login method, the user is permitted to log into the MFP  101  without inputting a password or personal information such as card information. In other words, the method involves no strict user authentication, and is inferior to the card authentication method and the keyboard authentication method in terms of security. On the other hand, the method is advantageous in that the login user can be identified through the simple operation. Accordingly, the method is effective in a case where the user logs in only through the operation of selecting the user name (icon corresponding to the user name), and a customized function (also referred to as a personalized function) of the MFP  101  according to the login user is provided thereto. 
     The authentication method setting unit  321  can also set a mode of operating the MFP  101 . The mode is either “a mode of requesting the user authentication when the MFP is used” or “a mode of requesting the user authentication when an application is selected (function dependent authentication mode)”. 
     The user management unit  322  manages user identification information about the user who is permitted to log into the MFP  101 . The user management unit  322  manages user accounts, registered in the user table illustrated in  FIG. 14 , including a user name  1401 , a password  1402 , a card ID  1403 , an email address  1404 , a group ID  1405 , an icon image  1406 , a latest login date and time  1407 , and a registered date and time  1408 . 
     In the present exemplary embodiment, the user accounts may be registered by a dedicated system administrator in advance or registered by each user through a registration option illustrated in  FIG. 4A . 
       FIG. 4A  is a user interface (UI) screen, displayed on the operation unit  208  by the CPU  201 , for setting a user account registration option. As illustrated in a setting screen  400  in  FIG. 4A , the user registration option includes a first registration method  401  in which “the user account is automatically registered when a job is input” and a second registration method  402  in which “the user account is manually registered from a setting menu”. 
     The first registration method  401  is a method in which reception of print data triggers registration of the owner name (owner information) included in the print data, in the user table illustrated in  FIG. 14 . When the first registration method  401  is enabled (ON) and print data is received, the owner of the print data is automatically added as the user account, which is not deleted in response to the deletion of the print data from the MFP  101 . 
     In the second registration method  402 , each user manually registers user identification information with a user registration button on the login screen  410 . 
     The dedicated system administrator sets whether each of the two registration methods is available or unavailable through the screen illustrated in  FIG. 4A . 
     The login screen display unit  324  performs login screen display control. For example, when the authentication method setting unit  321  has set the card authentication method, an authentication screen including a message such as “place your IC card over the card reader” is displayed. For example, when the keyboard authentication method has been set, an authentication screen including a message such as “input your user name and password” is displayed. When the icon selection method has been set as the authentication method, a login screen illustrated in  FIG. 4B  or  FIG. 4C  (described below) is displayed on the operation unit  208 . 
     The software configuration of the MFP  101  has been described above. In the present exemplary embodiment, the personal print application  310  manages the document holding user information, whereas the login application  320  manages the user accounts. The login application  320  obtains the document holding user information from the personal print application  310  when the login screen is displayed. Based on the obtained document holding user information, the login application  320  can display only a document holding user icon, display user icons giving high priority to the document holding user icons, or display the user icons having been subjected to sorting in a reverse chronological order or an ascending order of the received date and time of the print data. 
     &lt;Example of User Icon Selection Screen&gt; 
     A UI screen displayed on the operation unit  208  by the login screen display unit  324  when the icon selection method has been set is described with reference to  FIG. 4B . The login screen  410  is displayed when a predetermined condition is satisfied. More specifically, the login screen  410  is displayed immediately after the MFP  101  is activated or a user logs out when “the mode in which the user authentication is requested when the MFP is used” has been set by the authentication method setting unit  321 . Meanwhile, the login screen  410  is displayed when an application is selected on an application selection screen  600  (described below), in a case where “a mode in which the authentication is requested when an application is selected (function dependent authentication mode)”. In other words, the login screen  410  is displayed at a timing corresponding to the setting established by the authentication method setting unit  321 . 
     User icons  411  to  416  are each an icon for identifying the user who is permitted to log into the MFP  101 . The user can easily log in by selecting a corresponding one of the displayed user icons  411  to  416 . In the present exemplary embodiment, up to six user icons can be displayed on a single screen. When icons corresponding to all the users cannot be displayed on a single screen, a flick operation may be performed so that the screen changes to display a subsequent set of user icons. 
     A user registration button  415  is a button used for newly registering a user account. The user registration button  415  is displayed only when the second registration method  402  is set to be enabled (ON) in  FIG. 4A . When the user registration button  415  is pressed, the screen transitions to a user registration screen  500  illustrated in  FIG. 5A , where a user name  501 , a password  502 , a card ID  503 , an email address  504 , and an icon  505  can be registered. When this registration operation is completed, a user account is newly added to the user table illustrated in  FIG. 14 . The user name  501  is an example of identification information for identifying a login permitted user. The user name  501  is a required item, whereas the password  502 , the card ID  503 , the email address  504 , and the icon  505  are optional items. 
     A user edit button  416  is a button used for editing a user account that has been registered. When the user edit button  416  is pressed, the screen transitions to a user edit screen  510  illustrated in  FIG. 5B , where the items other than the user name  501 , namely, the password  502 , the card ID  503 , the email address  504 , and the icon  505  can be added or edited. 
     A user filter designation pull-down list  417  is used for filtering user icons to be displayed. When “display all” is selected with the user filter designation pull-down list  417 , all the user names registered in the user table illustrated in  FIG. 14  are displayed together with their icon images. When “print” is selected with the user filter designation pull-down list  417 , only icon images corresponding to the document holding users among the users registered in the user table are displayed as illustrated in  FIG. 4C . In the present exemplary embodiment, six Users  1  to  6  are registered in the user table, and only User  1 , User  2 , User  3 , and User  5  among Users  1  to  6  are document holding users. Accordingly, only information about these document holding users is displayed as a result of the filtering. In  FIG. 4C , User  1 , User  2 , User  3 , and User  5  are sorted by their received date to be displayed. 
     A sort pull-down list  418  is used for sorting the user icons to be displayed. When “sort by name” is selected with the sort pull-down list  418 , the user name icons are sorted in order of user names registered in the user table to be displayed. 
     &lt;Example of Application Selection Screen&gt; 
       FIG. 6  illustrates an application selection screen  600 . The application selection screen  600  is displayed at a timing corresponding to the setting established by the authentication method setting unit  321  of the login application  320 . In a case where “the mode in which the user authentication is requested when the MFP is used” has been set by the authentication method setting unit  321 , the application selection screen  600  is displayed when the user icon  411  is selected on the login screen  410 . On the other hand, when “the function dependent authentication mode” has been set, the application selection screen  600  is displayed immediately after the MFP  101  is activated or logout of a user. In other words, the application selection screen  600  is displayed at a timing corresponding to the setting established by the authentication method setting unit  321 . 
     Buttons  601 ,  602 , and  603  are displayed on the application selection screen  600 , and respectively correspond to the copy application  301 , the personal print application  310 , and the transmission application  302 . 
     &lt;Example of Document List Screen&gt; 
     When the button  602 , corresponding to the personal print application  310 , is pressed on the application selection screen  600 , a held document list screen  800 , illustrated in  FIG. 7 , is displayed. 
     In  FIG. 7 , only documents of the login user are displayed on the held document list screen  800 , so that the user can easily find his or her document. In a held document list  801 , print settings of the held document, the received date and time of the print data, and the like which are associated with User  1  as the login user and stored in the bibliographic information storage unit  313  are displayed. When the user instructs the printing of a held document, the user selects a desired document from the held document list displayed in the held document list  801 , and presses a start printing button  804 . When the user deletes a desired held document, the user can delete the held document from the print data management unit  311  by selecting the desired held document and pressing a delete button  803 . The user can perform a desired operation with a held document selected one at a time, or with all the held documents selected by pressing a select all button  802 . 
     &lt;Operation at Activation&gt; 
       FIG. 9  is a flowchart illustrating processing, executed in activating, for registering a callback function for acquiring a list of users for which held documents are held. A program for executing each step in the flowchart illustrated in  FIG. 9  is stored in the ROM  203  or the HDD  204 , and is executed by the CPU  201 . 
     First, in step S 901 , the personal print application  310  acquires the settings of the MFP  101  in activation processing, and determines whether the following two setting items are enabled (ON). 
     The first setting item is a setting for determining whether “a user account is automatically registered when a job is input” described with reference to  FIG. 4A . The second setting item is a setting for determining whether “an input job is forcibly held” as illustrated in  FIG. 8 . These setting items are set by a dedicated system administrator in advance. 
     In step S 901 , when it is determined that the setting “a user account is automatically registered when a job is input” is ON (YES in step S 901 ). The processing proceeds to step S 902 . In step S 902 , when it is determined that the setting “an input job is forcibly held” is ON (YES in step S 902 ), the processing proceeds to step S 903 . On the other hand, the personal print application  310  terminates the processing in  FIG. 9  when any one of the setting items is OFF (NO in step S 901  or S 902 ). 
     In step S 903 , the personal print application  310  instructs the login application  320  to register the call back function for acquiring the user list. In step S 904 , the login application  320  receives the request to register the call back function for acquiring the user list from the personal print application  310 , and registers the call back function. The call back function is called by the login application  320  when the login processing is performed through the icon selection method. 
     &lt;Processing in Receiving Print Data&gt; 
       FIG. 10  is a flowchart illustrating processing executed when data transmitted from the PC  102  through the LAN  100  is accumulated or printed. The processing in steps S 1001  and S 1002  illustrated in the flowchart in  FIG. 9  is executed by the PC  102 . The processing in and after step S 1003  is executed by the MFP  101 . More specifically, a program for executing the processing in and after step S 1003  is stored in the ROM  203  or the HDD  204  of the MFP  101  and is executed by the CPU  201 . 
     In step S 1001 , the printer driver of the PC  102  is called when a print menu is displayed by the user on various applications, and displays a print setting screen. When a print instruction is received from the user through the print setting screen, the printer driver converts data in the application into data printable by the MFP  101  to generate print data. In step S 1002 , the printer driver transmits the print data generated in step S 1001  to the MFP  101 . 
     In step S 1003 , the personal print application  310 , operating on the MFP  101 , receives the print data transmitted from the printer driver of the PC  102  in step S 1002 . In step S 1004 , the personal print application  310  obtains the setting information about MFP  101  and checks whether the setting item “an input job is forcibly held” illustrated in  FIG. 8  is enabled (ON). This setting item is set by the dedicated system administrator in advance. In step S 1004 , when the setting item is disabled (OFF) (NO in step S 1004 ), the processing proceeds to step S 1005 , where the personal print application  310  executes print control. In this manner, the print data received is rasterized into bitmap image data by the raster image processor  210 , and is output to the printer unit  212 . The printer unit  212  performs printing on a sheet based on the output data. 
     In step S 1004 , when the setting item “an input job is forcibly held” is enabled (YES in step S 1004 ), the processing proceeds to step S 1006 . In step S 1006 , the personal print application  310  acquires bibliographic information from the print data received in step S 1003 . The bibliographic information includes the owner name (owner information), a document name of the print data, the received date and time of the print data, the print setting information set by the user, and the like. In step S 1007 , the personal print application  310  stores the print data for which the bibliographic information is properly extracted in the HDD  204  of the MFP  101  as a held document. The print data to be stored in step S 1007  may be stored as a page description language data or may be a bitmap image as a result of the rasterization by the raster image processor  210 . 
     In step S 1008 , the personal print application  310  stores, in the HDD  204  of the MFP  101 , the bibliographic information acquired in the step S 1004  in association with the job owner name of the print data acquired from a header of the print data. In step S 1009 , the personal print application  310  adds the job owner name, acquired in step S 1006 , to the top of the document holding user list illustrated in  FIG. 12 . When the user with this job owner name has been already registered in the document holding user list, the user is moved to the top of the document holding user list. Through the processing executed in step S 1009 , the job holding user list is constantly managed in a state where the users are sorted by the received date and time. 
     In step S 1010 , the personal print application  310  acquires the settings of the MFP  101 , and determines whether the setting item “a user account is automatically registered when a job is input” illustrated in  FIG. 4A  is ON. When it is determined that the setting item is ON (YES in step S 1010 ), the processing proceeds to step S 1011 , where the personal print application  310  instructs the login application  320  to register the job owner name, acquired in step S 1006 , in the user table managed by the login application  320 . 
     In step S 1012 , when the login application  320  receives the registration instruction from the personal print application  310 , the processing proceeds to step S 1013 . In step S 1013 , the login application  320  determines whether the user name matching the received job owner name has been already registered in the user table. When such a user name has been already registered (YES in step S 1013 ), the processing is terminated. When such a user name is not registered (NO in step S 1013 ), the received job owner name is newly added to the user name  1401  as an item in the user table. 
     The MFP  101  performs operation in the aforementioned manner when receiving the print data. 
     &lt;Processing Executed in Displaying Login Screen&gt; 
       FIG. 11  is a flowchart illustrating processing executed by the login application  320  when the login application  320  displays the login screen  410  on the operation unit  208 . A program for executing each step illustrated in the flowchart in  FIG. 11  is stored in the ROM  203  or the HDD  204  and is executed by the CPU  201 . 
     In step S 1100 , the login application  320  receives a display request for displaying the login screen. Then, in step S 1101 , the login application  320  determines whether the received display request is a request received after the personal print application  310  is selected on the application selection screen  600 . For example, when the MFP  101  is operating in a normal mode, the login screen is displayed immediately after the MFP  101  is activated or logout of a user. Thus, in this case, the result of the determination in step S 1101  is “NO”. On the other hand, for example, the MFP  101  also operates in a mode in which the login screen is displayed when the application is selected (“function dependent authentication mode” described above) depending on the mode of the MFP  101 . When the MFP  101  is operating in the function dependent authentication mode and the personal print application  310  is selected on the application selection screen  600 , the result of the determination in step S 1101  is “YES”. In other words, when the result of the determination in step S 1101  is “YES”, the user is likely to use the MFP  101  to perform an operation of printing or deleting a document held in advance. For that reason, when the login screen is displayed, it is desirable to display only the document holding user icons or display user icons with giving high priority to the document holding user icons. Accordingly, in the present exemplary embodiment, in order for the login application  320  to acquire the document holding user list from the personal print application  310 , the processing proceeds to step S 1103 . In addition, even when the MFP  101  is operating in the function dependent authentication mode, if an application (the copy application  301  or the transmission application  302 ) other than the personal print application  310  has been selected on the application selection screen  600 , the result of the determination in step S 1101  is “NO” and the processing proceeds to step S 1102 . 
     In step S 1102 , the login application  320  determines whether a display request for displaying the job holding user icons (and the user name) is to be issued. For example, the display request for displaying the job holding user icon(s) is issued when “print” is selected from the items of the user filter designation pull-down list  417 . When the result of the determination in step S 1102  is “YES”, the processing proceeds to step S 1103 . 
     In step S 1103 , the login application  320  determines whether the callback function for acquiring the user list has been registered by the personal print application  310 . In step S 1103 , when it is determined that the callback function for acquiring the user list has been registered by the personal print application  310  (YES in step S 1103 ), the processing proceeds to step S 1104 . On the other hand, when it is determined that the callback function for acquiring the user list has not been registered by the personal print application  310  (NO in step S 1103 ), the processing proceeds to step S 1112 . 
     In step S 1104 , the login application  320  transmits the acquisition request for the document holding user list by using the call back function registered in step S 904 . In step S 1105 , the personal print application  310  receives the user list acquisition request transmitted from the login application  320  in step S 1104 . In step S 1106 , the personal print application  310  transmits the document holding user list illustrated in  FIG. 12  to the login application  320 . The document holding user list, transmitted from the personal print application  310 , is sorted in the order of receiving the print data. 
     In step S 1107 , the login application  320  acquires the document holding user list sorted in the order of receiving the print data transmitted from the personal print application  310 . 
     In step S 1108 , the login application  320  extracts the document holding user in the document holding user list, acquired from the personal print application  310  in step S 1107 , one by one from the top of the list. Then, in step S 1109 , the login application  320  determines whether the document holding user has been registered in the user table in the user management unit  322 . 
     For example, the document holding user is not registered in the user table when, for example, print data is stored in the HDD  204  by the personal print application  310  as a held document but the user account of the owner of the held document has been deleted by the login application  320 . 
     In step S 1109 , when the login application  320  determines that the document holding user has been registered in the user table as a result of the processing in step S 1008  (YES in step S 1109 ), the processing proceeds to step S 1110 . In step S 1110 , the login application  320  adds the document holding user to the user list used for generating the login screen. The user list used for generating the login screen is a list of users to be displayed on the login screen. When a user is added to the user list, the icon image and the user name of this user are displayed in the processing in step S 1118  (described below). 
     In step S 1109 , when the login application  320  determines that the document holding user has not been registered in the user table as a result of the processing in step S 1008  (NO in step S 1109 ), the processing for adding the information about the user to the user list used for generating the login screen is skipped and the processing proceeds to step S 1111 . 
     In step S 1110 , the login application  320  determines whether information about all the job holding users in the job holding user list acquired in step S 1107  has been checked. When not all the information about the job holding users has been checked (NO in step S 1110 ), the processing returns to step S 1108 , and the processing in steps S 1109  and S 1110  is executed for the next job holding user. On the other hand, when all information about the job holding users has been checked (YES in step S 1110 ), the processing proceeds to step S 1116 . 
     In step S 1116 , the login application  320  determines whether there is no record in the user list used for generating the login screen. When it is determined that there is no record (YES in step S 1116 ), the processing proceeds to step S 1118 . On the other hand, when it is determined that there are one or more records (NO in step S 1116 ), the processing proceeds to step S 1117 . 
     In step S 1117 , the login application  320  acquires the user identification information associated with each user from the user table ( FIG. 14 ). The identification information to be acquired includes the user name  1401  and the icon image  1406  illustrated in  FIG. 14 . 
     In step S 1118 , the login application  320  displays the login screen on the operation unit  208 . When it is determined in step S 1116  that the user list used for generating the login screen includes no record (YES in step S 1116 ), the login screen with no user icon image is displayed. When it is determined in step S 1116  that the user list used for generating the login screen includes one or more records (NO in step S 1116 ), the login screen (see  FIG. 4B or 4C ) including the icon image and the user name acquired in step S 1117  that correspond to the user is generated and displayed on the operation unit  208 . 
     The processing in steps S 1112  to S 1115  is executed when a request for filtering or sorting the user icons to be displayed on the login screen has been issued. For example, such a request is issued by the user through the user filter designation pull-down list  417  or the sort pull-down list  418  on the login screen  410  in  FIG. 4B or 4C . 
     In step S 1112 , the login application  320  determines whether a filter request or a sort request has been issued. When it is determined that the filter request has been issued (“filter” in step S 1112 ), the processing proceeds to step S 1113 . In step S 1113 , the login application  320  filters information about the users registered in the user table based on a predetermined filter condition. Then in step S 1115 , the login application  320  adds the information about the user obtained after the filtering to the user list for generating the login screen. Various possible examples of the predetermined condition include whether a user has logged in within a predetermined time period, or whether a user having a user name includes a predetermined character string. 
     In step S 1114 , the login application  320  sorts the information about the users registered in the user table based on a predetermined sorting condition. Then, in step S 1115 , the login application  320  adds the information about user (s) obtained after the sorting to the user list used for generating the login screen. Various examples of the predetermined sorting condition include conditions using an order by name and an order of latest login date and times. Furthermore, a sorting condition of displaying a job holding user information with a priority over other users may be employed. This sort processing based on the job holding user information is executed based on the job holding user list acquired from the personal print application  310 . 
     As described above, the printing apparatus according to the exemplary embodiment described above acquires the document holding user information from the personal print application  310  when displaying the login screen in the icon selection method. Then, the printing apparatus displays the login screen based on the acquired document holding user information. In other words, only the document holding user information among the user information registered in the user table can be displayed, the document holding user information can be displayed with high priority, or the user list can be displayed on the login screen based on the sorted order of the document holding user information. 
     Although not illustrated in  FIG. 11 , a user presses a corresponding user icon on the displayed login screen to log into the MFP  101 . When the document list screen is displayed in a state where the user has logged in, only documents of the user is displayed in a list, so that the user can easily find his or her document. 
     The present invention can also be achieved by the process of supplying software (program) for implementing a function of an above exemplary embodiment to a system or an apparatus via a network or various storage media, and causing a computer (or a CPU or a microprocessor unit (MPU)) of the system or the apparatus to read and execute the program. In such a case, the program and the storage media storing the program configures the present invention. 
     With the present invention, a login application can display user identification information on a login screen based on document input user information acquired from a print application. 
     Embodiment(s) of the present invention can also be realized by a computer of a system or apparatus that reads out and executes computer executable instructions (e.g., one or more programs) recorded on a storage medium (which may also be referred to more fully as a ‘non-transitory computer-readable storage medium’) to perform the functions of one or more of the above-described embodiment(s) and/or that includes one or more circuits (e.g., application specific integrated circuit (ASIC)) for performing the functions of one or more of the above-described embodiment(s), and by a method performed by the computer of the system or apparatus by, for example, reading out and executing the computer executable instructions from the storage medium to perform the functions of one or more of the above-described embodiment(s) and/or controlling the one or more circuits to perform the functions of one or more of the above-described embodiment(s). The computer may comprise one or more processors (e.g., central processing unit (CPU), micro processing unit (MPU)) and may include a network of separate computers or separate processors to read out and execute the computer executable instructions. The computer executable instructions may be provided to the computer, for example, from a network or the storage medium. The storage medium may include, for example, one or more of a hard disk, a random-access memory (RAM), a read only memory (ROM), a storage of distributed computing systems, an optical disk (such as a compact disc (CD), digital versatile disc (DVD), or Blu-ray Disc (BD)™), a flash memory device, a memory card, and the like. 
     While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.