CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    The present application claims priority from Japanese Patent Application No. 2012-170234, filed on Jul. 31, 2012, the disclosure of which is incorporated herein by reference in its entirety. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a display control apparatus configured to control a display of a setting value for each of a plurality of types of setting items, a display control method, and a storage medium storing instructions for the display control apparatus. 
         [0004]    2. Description of the Related Art 
         [0005]    An information processing device such as a personal computer (hereinafter, referred to as “PC”), and various types of peripheral devices such as a printer and a scanner which are used upon being connected to the PC (or used alone) include, in general, a user interface for allowing a user to view setting contents (setting values), and for receiving an operation such as selection and change of each of the setting values, with respect to a plurality of types of setting items to be used for realizing various functions. For instance, in a scanner, by displaying a setting screen for displaying various setting items (such as a resolution, a document size, and a color type) necessary for reading a document on a display section, the user is capable of knowing a current setting state. Moreover, by carrying out a predetermined operation in a state that the setting screen is displayed, the user is able to select and change the setting values of each setting item appropriately, and make the scanner carry out scanning 
         [0006]    With a high functionality of various devices in recent years, setting items which can be set in one function or application tend to increase. As the setting items which can be set increase, it is possible to provide a wide variety of functions and services to the user. However, at the same time, a user interface becomes complicated, and operability and usability are degraded. 
         [0007]    In view of this, in Japanese Patent Application Laid-open No. 2011-34515, a technology that improves the operability of a process from selection of the setting items up to parameter determination has been disclosed. Concretely, the setting screen is formed to be divided into a setting-item display area, a selection area, and a determination area. As the user shifts (drags and drops) one of the plurality of types of setting items displayed in the setting-item display area to the selection area, all parameters which can be set for the setting item are displayed in the selection area. As a desired parameter among all the parameters displayed in the selection area is shifted to the determination area, the parameter of the setting item is determined. 
       SUMMARY OF THE INVENTION 
       [0008]    However, in a case that an arrangement is made such that each of the setting values of the plurality of setting items can be selected, the values of the setting items may be mutually exclusive and cannot be selected simultaneously due to a mechanical constraint or a hardware constraint. For instance, in a scanner, in a case that double-sided scanning of a document is selected to be effective, a flatbed setting cannot be selected as a paper feeding method. In other words, the double-sided scanning and the flatbed setting are mutually exclusive, are in conflict with each other, and hence cannot be set at the same time. 
         [0009]    In a case that there is an exclusive setting value which is exclusive to a setting value selected by the user and which belongs to a setting item different from a setting item to which the setting value selected by the user belongs, if the presence of the exclusive setting value is not specified clearly by some sort of technique, it is difficult to understand as to what value can be selected and what value cannot be selected, and there is a possibility that the usability for the user in selecting the setting value is degraded. Therefore, in a case that there is the exclusive setting value which is exclusive to the setting value selected by the user, it is desired that the user is able to know the presence of the exclusive value easily and specifically. 
         [0010]    The present invention has been made in view of the abovementioned issues, and an object of the present invention is to improve the usability for the user at the time of selecting the setting value by arranging such that the user can aware easily and specifically of the exclusive setting value which is exclusive to the setting value selected by the user and which belongs to a setting item different from a setting item to which the setting value selected by the user belongs. 
         [0011]    According to an aspect of the present invention, these is provided a display control apparatus configured to control a display to display contents in a first display area, a second display area, and a third display area on the display, the display control apparatus including: a control section for controlling the display configured to: display at least one setting value in the first display area for each of a plurality of setting items; allow a user to select one of the at least one setting value, displayed in the first display area, in a particular setting item; receive a user&#39;s selection of the one of the at least one setting value as an effective setting value for each of the plurality of setting items; display the selected setting value in the second display area in receipt of the user&#39;s selection; determine whether there is an exclusive setting value in the setting values, that are displayed in the first display area and belong to any setting item other than the particular setting item, the exclusive setting value being inadequate to be selected with the selected setting value; and display the exclusive setting value in the third display area as a non-selectable setting value when determined that there is the exclusive setting value. 
         [0012]    According to the display control apparatus of the present invention configured in such manner, in a case that the user has carried out an operation of selecting a desired setting value from the first display area, the setting value which has been selected is not only displayed in the second display area, but the exclusive setting value which is exclusive to the setting value selected by the user is displayed in the third display area. Therefore, the user is able to know easily and specifically that there is the exclusive setting value which belongs to a setting item different from a setting item to which the setting value selected by the user belongs. Accordingly, it is possible to improve usability for the user at the time of selecting the setting value. 
         [0013]    In the present invention, “displaying” a “setting value” not only means to display the setting value, but also includes displaying various types of information expressing the setting value directly or indirectly, such as displaying an image of a symbol or an icon indicating the setting value for example. 
         [0014]    Moreover, it is possible to realize each processing executed by the control section of the abovementioned display control apparatus of the present invention as instructions which cause a computer to execute each processing, and as a storage medium storing such instructions. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0015]      FIG. 1  is a block diagram showing a schematic configuration of an information processing system according to an embodiment. 
           [0016]      FIG. 2A  is a diagram showing an example of an initial-screen of a scan setting screen, 
           [0017]      FIG. 2B  is an example of an exclusive-relationship table, and  FIG. 2C  is an example of an initial display area presetting table. 
           [0018]      FIG. 3A  is a diagram showing an item-shift example 1 on the scan setting screen, and 
           [0019]      FIG. 3B  is a diagram showing an item-shift example 2 on the scan setting screen. 
           [0020]      FIG. 4A  is a diagram showing an item-shift example 3 on the scan setting screen, and 
           [0021]      FIG. 4B  is a diagram showing an item-shift example 4 on the scan setting screen. 
           [0022]      FIGS. 5A and 5B  show a flowchart depicting a setting-screen display processing executed by a CPU of a PC. 
           [0023]      FIGS. 6A ,  6 B and  6 C show a flowchart depicting a setting-operation receiving processing executed by the CPU of the PC. 
           [0024]      FIG. 7  is flowchart showing a basic sub-processing in  FIG. 6A . 
           [0025]      FIGS. 8A and 8B  show a flowchart depicting a first sub-processing in  FIGS. 6A to 6C . 
           [0026]      FIG. 9  is a flowchart showing a second sub-processing in  FIG. 6C . 
           [0027]      FIGS. 10A and 10B  show a flowchart depicting a third sub-processing in  FIGS. 6A to 6C . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0028]    An exemplary embodiment of the present invention will be described below by referring to the accompanying diagrams. An information processing system  1  according to the embodiment, as shown in  FIG. 1 , is a system formed by a PC (Personal Computer)  2  and an MFP (Multi-Function Peripheral)  3  which are communicably connected each other via a network  5 . The MFP  3  is a so-called multifunction device which includes various functions such as a scanner function of scanning an image of a document and a printer function of printing an image on a recording medium such as a recording paper and an OHP (Over Head Projector) sheet. 
         [0029]    The PC  2  as a display control apparatus has a known configuration including a CPU (Central Processing Unit)  11 , a ROM (Read Only Memory)  12 , a RAM (Random Access Memory)  13 , a hard disc drive (HDD)  14 , an input section  15 , a display section  16 , a USB (Universal Serial Bus) interface  17 , and a LAN (Local Area Network) interface  18 . The input section  15  includes a known mouse device  19  which is operated by a user, and a keyboard which is not shown in the diagram. The display section  16  is formed by a display device such as a liquid-crystal display. 
         [0030]    Various software are installed in the HDD  14 . The various software include a software (hereinafter, called as a “scanning software”) which is capable of giving an instruction to read (scan) an image by controlling the scanner function of the MFP  3  while communicating with the MFP  3 , and capable of processing image data scanned by and received from the MFP  3 . In the scanning software, a user can set various setting items (such as color type, resolution, and document size) which are used by the MFP  3  at the time of scanning The CPU  11  which executes the scanning software is an example of a control section which controls the display section  16 . 
         [0031]    The MFP  3  includes a CPU  21 , a ROM  22 , a RAM  23 , an operating and display section  24 , a LAN interface  26 , a USB interface  27 , a scanner section  28 , and a printer section  29 . The CPU  21  executes control and computing of each section in the MFP  3  according to various computer programs and data stored in the ROM  22 . The RAM  23  is used as a main memory which is directly accessible from the CPU  21 . The operating and display section  24  includes a touch panel  25  and push buttons which are not shown in the diagram. The scanner section  28  includes an image sensor and generates image data corresponding to an image of a document which has been read. The printer section  29  prints an image on a recording medium. 
         [0032]    The MFP  3  includes a flatbed on which a document is to be placed, and an automatic document feeder (hereinafter, called as an “ADF”) which transports a document automatically. At the time of scanning a document, the user can select whether the document is to be placed on the flatbed, or the document is to be fed by the ADF. 
         [0033]    Next, a setting procedure by the user at the time of setting various scanning parameters for the scanning software of the PC  2  will be described below concretely. For setting various setting items, to begin with, the user boots up the scanning software. As the user carries out a predetermined operation for invoking a scan-setting screen from a main-menu screen of the scanning software, an initial screen of the scan-setting screen as shown in  FIG. 2A  is displayed on the display section  16 . In the embodiment, color type, resolution, document size, double-sided scanning, document-size identification, and paper feeding method are set as setting items for scanning which can be set on the scan-setting screen. 
         [0034]    From among these items, the color type indicates a type of color (number of colors) to be scanned, and in the embodiment, one of three parameters (setting values) namely monochrome, gray, and color can be set (selected). As for the resolution, in the embodiment, one of five parameters (setting values) namely 100 dpi (dots per inch), 200 dpi, 300 dpi, 600 dpi, and 1200 dpi can be selected. Regarding the document size, in the embodiment, one of five types of parameters (setting values) namely, legal, letter, A4, B5, and business card can be selected. The paper feeding method indicates how to set a document, and in the embodiment, one of three parameters (setting values) namely “FB” (flatbed) which indicates scanning a document by placing the document on the flatbed, “ADF” which is a method of feeding the document by using the ADF, and “auto” which is a method of making the MFP  3  identify the “FB” and the “ADF” automatically, can be selected. 
         [0035]    The double-sided scanning indicates a function of scanning two surfaces of a document automatically (hereinafter, called as “double-sided scanning”), and in the embodiment, it is possible to select whether the double-sided scanning function is effective or not. Therefore, a parameter (setting value) which can be set for the double-sided scanning is “double-sided scanning ON” which makes the double-sided scanning function effective. When the parameter “double-sided scanning ON” is selected, the double-sided scanning function becomes effective, whereas, when the parameter “double-sided scanning ON” is not selected, the double-sided scanning function becomes ineffective. The double-sided scanning function is a function which cannot be executed in a state that a document is placed on the flatbed, and can be executed in a case of feeding the document by the ADF. 
         [0036]    The document size identification is a function of identifying automatically a size of a document that has been placed on the flatbed (hereinafter, called as a “document-size identification function”), and in the embodiment, it is possible to select whether the document-size identification function is effective or not. Therefore, a parameter (setting value) which can be set for the document-size identification is “document-size identification ON” which makes the document-size identification function effective. When the “document-size identification ON” is selected, the document-size identification functions becomes effective, whereas, when the “document-size identification ON” is not selected, the document-size identification function becomes ineffective. 
         [0037]    The document-size identification function, more specifically, is a function of generating and saving image data upon dividing an image separately for each of a plurality of documents by one scanning operation at the time of executing scanning in a state that a plurality of documents (such as a business card and a card) are placed on the flatbed. Therefore, in a case of scanning by using the document-size identification function, it is necessary to execute upon placing the documents on the flatbed. 
         [0038]    The scan-setting screen, as shown in  FIG. 2A , has a first area  41  in which parameters of each setting item are displayed as a list for each setting item, a second area  42  in which a parameter which has been selected and set from among the parameters of the setting items is displayed, and a third area  43  in which a parameter which can not be selected at the current point of time from among the parameters of the setting items is displayed. 
         [0039]    On the scan-setting screen, each parameter is displayed as an image in the form of a substantially rectangular-shaped icon (hereinafter, called as “item”) as shown in  FIG. 2A . In the following description, when a word “item” is used, it denotes not only an image in the form of an icon which has been displayed on the scan-setting screen, but also the corresponding parameter (setting value). 
         [0040]    The user can shift a desired item (parameter) between different areas by a drag-and-drop operation using the mouse device  19 . However, in the embodiment, it is possible to shift the items from the first area  41  to the second area  42 , from the second area  42  to the first area  41 , and from the third area  43  to the second area  42 . 
         [0041]    In the first area  41 , items which can be selected by the user are displayed as a list. Basically, all the items for each of the setting items are displayed in the first area  41 . However, in the embodiment, the items which have been already selected and displayed in the second area  42  and the items which have been displayed in the third area  43  as non-selectable items are displayed to be grayed-out. It is not necessary to display these items to be grayed-out in such manner in the first area  41 , and it is possible to display these items in the first area  41  in a manner other than grayed-out, or an arrangement may be made not to display these items in the first area  41  at all. 
         [0042]    An item which has already been selected and set (selected item) is displayed in the second area  42 . In the initial screen shown in  FIG. 2A , “monochrome”, “200 dpi”, “A4”, and “auto” are displayed as “selected items” in the second area  42 . The initial screen indicates that “monochrome” has been selected as the color type, “200 dpi” has been selected as the resolution, “A4” has been selected as the document size, “auto” has been selected as the paper feeding method, and any item has not been selected from both of the “double-sided scanning” and the “document-size identification”. 
         [0043]    In the third area  43 , an item which cannot be selected is displayed. The item which cannot be selected means an item which is exclusive to the “selected item” displayed in the second area  42 . In the embodiment, in principle, although it is possible for the user to select any desired item for each of the setting items, there exist some combinations of items which cannot be selected at the same time (they are mutually exclusive) among the setting items which are different from one another. The combination of the exclusive relationship is set in advance in an exclusive-relationship table shown in  FIG. 2B . The exclusive-relationship table has been stored in the HDD  14  as a part of the scanning software. The exclusive-relationship table is an example of the exclusive-relationship information. 
         [0044]    Combinations of items which are mutually exclusive are listed up in the exclusive-relationship table as shown in  FIG. 2B . For instance, “color” in the color type and “1200 dpi” in the resolution are mutually exclusive and cannot be selected at the same time. In such manner, due to a software constraint or a mechanical constraint, there exist a plurality of combinations of items which are mutually exclusive, and the exclusive-relationship table ( FIG. 2B ) in which the combinations of items are listed up has been stored in the HDD  14  as a part of the scanning software. 
         [0045]    In the initial screen shown in  FIG. 2A , each of the “selected item” displayed in the second area  42  is an item which is not exclusive to any items. Therefore, in the initial state, there exists no non-selectable item which cannot be selected, and no non-selectable item is displayed in the third area  43 . 
         [0046]    In an initial state (default) when the scanning software is booted up and the scan setting screen is displayed in the beginning, the items are set as shown in  FIG. 2A , and when an OK button is clicked in this state, scanning of a document with the setting condition is carried out. As to which item is to be displayed in which area in the initial state (in other words, as to which item is in a selection state and as to which item is in a non-selection state) has been set in advance in an initial display area presetting table shown in  FIG. 2C . 
         [0047]    The initial display area presetting table has been stored in the HDD  14  as a part of the scanning software. The initial display area presetting table defines initial display area of each parameter of each setting item from among the three areas namely, the first area  41 , the second area  42 , and the third area  43  on the scan setting screen. In other words, the initial display area presetting table defines items which are in the selection state in the initial state. As the user boots up the scanning software and carries out a predetermined operation for displaying the scan setting screen, the initial display area presetting table shown in  FIG. 2C  is referred to, and accordingly, the initial screen shown in  FIG. 2A  is displayed on the display section  16 . 
         [0048]    However, in the embodiment, every time the scanning software is terminated, setting contents at the time of termination (hereinafter, called as “previous setting contents”) are saved in the HDD  14  as a setting file. Moreover, when the scanning software is booted once again subsequently and the initial screen is displayed, if the previous setting contents are saved as the setting file, the previous setting contents are displayed on a priority basis. 
         [0049]    The user can also make a setting such that the previous setting contents are not saved, and can also make a setting such that the previous setting contents are ignored and default setting contents are displayed every time. To save the previous setting contents as a setting file is an example, and the previous setting contents may be saved in a registry, or may be saved upon compiling as a database, and the previous setting contents may be acquired from the database. 
         [0050]    The user can change the setting contents of the initial screen in  FIG. 2A . For instance, when the user wants to change the resolution from “200 dpi” to “300 dpi”, as the user drags and drops the item “300 dpi” from the first area  41  to an arbitrary position in the second area  42 , “300 dpi” is displayed at a predetermined position (a position at which “200 dpi” had been displayed) in the second area  42  as shown in  FIG. 3A . With this, “200 dpi” which had been displayed in the second area  42  originally, is shifted automatically to the first area  41 . Concretely, as shown in  FIG. 3A , “200 dpi” is changed from a grayed-out state to a normal-display state. Accordingly, “200 dpi” can be selected. 
         [0051]    Moreover, for instance, in the state shown in  FIG. 3A , when the item “300 dpi” which has been selected currently is dragged and dropped from the second area  42  to the first area  41  (dropped at an arbitrary position in the first area  41 ), the item “300 dpi” is displayed normally in the first area  41 . With this, in the second area  42 , an item which had been selected immediately before “300 dpi”, or, an item which is default-set is displayed as the resolution. 
         [0052]    The example in  FIG. 3A  is an example of shifting an item which is not exclusive to any other item, and in a case that an item which is exclusive to another item is selected, an item which is exclusive to the selected item is shifted automatically from the first area  41  to the third area  43  as a “non-selectable item”. For instance, as exemplified in  FIG. 3B , if the user shifts the item “double-sided scanning ON” to the second area  42  in order to make the double-sided scanning function effective, the “document-size identification ON” and the “FB” which are exclusive to the “double-sided scanning ON” are shifted automatically to the third area  43  respectively, and these items cannot be selected by the user. 
         [0053]    In the state exemplified in  FIG. 3B , as the user shifts the item “double-sided scanning ON” from the second area  42  to the first area  41  in order to make the double-sided scanning function ineffective, both the “document-size identification ON” and the “FB” which had been displayed in the third area  43  as the “non-selectable item” are shifted automatically to the first area  41 , and are displayed normally once again as the “selectable item”. 
         [0054]    On the other hand, in the sate exemplified in  FIG. 3B , in order to make the document-size identification function effective, the user can shift the item “document-size identification ON” displayed in the third area  43  to the second area  42  as exemplified in  FIG. 4B . In other words, it is possible to change an item from the “non-selectable item” to the “selected item” forcibly. 
         [0055]    However, in a case that the item “document-size identification ON” is shifted to the second area  42 , since the “document-size identification ON” and the “double-sided scanning ON” are exclusive to each other, the item “double-sided scanning ON” is shifted automatically from the second area  42  to the third area  43  as the “non-selectable item”. Moreover, the paper feeding method “ADF” is exclusive to the “document-size identification ON” (refer to  FIG. 2B ). Therefore, the item “ADF” displayed as the “selectable item” in the first area  41  is also shifted automatically to the third area  43  as the “non-selectable item”. 
         [0056]    Furthermore, as a result of shifting the item “double-sided scanning ON” from the second area  42  to the third area  43  as the “non-selectable item”, the item “FB” which had been displayed in the third area  43  is shifted automatically to the first area  41 , and is displayed once again as the “selectable item”. 
         [0057]    Next, in order to realize display examples and shifting examples of the abovementioned items, each processing executed by the CPU  11  of the PC  2  will be described below in detail while referring to flowcharts shown in  FIG. 5A  to  FIG. 10B . All the flowcharts shown in  FIG. 5A  to  FIG. 10B  are saved in the HDD  14  as a part of a computer program that forms the scanning software. 
         [0058]    As the scanning software is booted up and a predetermined operation for calling a scan-setting screen is carried out by the user, the CPU  11  starts a setting-screen display processing as shown in  FIGS. 5A and 5B . As the CPU  11  starts the setting-screen display processing in  FIGS. 5A and 5B , firstly, at step S 110 , the CPU  11  acquires an item total-number V which is the total number of items. As the CPU  11  acquires the item total-number V, the CPU  11  sets an item number v to 1 at step S 120 . 
         [0059]    At step S 130 , the CPU  11  judges whether or not a setting at the time of previous display has been saved. In other words, as it has already been mentioned, in the embodiment, every time the scanning software is terminated, the setting contents at the time of termination (previous setting contents) are saved in the HDD  14  as a setting file. Therefore, the CPU  11  judges whether or not the previous setting contents have been saved. In a case that the previous setting contents have not been saved, or in a case that the setting is made such that the previous setting contents are not saved (NO at step S 130 ), the CPU  11  reads the initial display area presetting table ( FIG. 2C ) at step S 140 . Whereas, in a case that the previous setting contents have been saved (YES at step S 130 ), the CPU reads the previous setting contents from the setting file at step S 150 . 
         [0060]    At step S 160 , the CPU  11  judges whether or not the display area of the v th  item is the first area  41  by using the information read at step S 140  or step S 150 . In a case that the display area of the v th  item is set as the first area  41  (YES at step S 160 ), the CPU  11  displays the v th  item at a predetermined position in the first area  41  on the scan-setting screen at step S 170 . Moreover, the CPU  11  increments the item number v by 1 at step S 210 , and the CPU  11  judges whether or not all the item number v at the current time is greater than the item total-number V at step S 220 . In a case that the item number v is greater than the item total-number V (YES at step S 220 ), the CPU  11  terminates the setting-screen display processing. In a case that the item number v is not greater than the item total-number V (NO at step S 220 ), the process returns to step S 160  and the CPU continues processing. 
         [0061]    In a case that at step S 160 , the display area of the v th  item is not set as the first area  41  (NO at step S 160 ), the process advances to step S 180 , and the CPU  11  judges whether or not the display area of the v th  item is the second area  42 . In a case that the display area of the v th  item is set as the second area  42  (YES at step S 180 ), the CPU  11  displays the v th  item (as a selected item) at a position in the second area  42  on the scan-setting screen at step S 190 , and the process advances to step S 210 . 
         [0062]    In a case that the display area of the v th  item is not set as the second area  42  (NO at step S 180 ), the process advances to step S 200 , and the CPU  11  displays the v th  item (as a non-selectable item) at a predetermined position in the third area  43  on the scan-setting screen, and the process advances to step S 210 . 
         [0063]    As the CPU  11  displays the initial screen by the setting-screen display processing in  FIGS. 5A and 5B , next, the CPU  11  starts a setting-operation receiving processing shown in  FIGS. 6A to 6C . The setting-operation receiving processing is executed repeatedly at every predetermined timing after the setting-screen display processing in  FIGS. 5A and 5B . As the CPU  11  starts the setting-operation receiving processing, at step S 310 , the CPU  11  judges whether or not an item shifting operation (shifting operation as exemplified in  FIG. 3 ) from the first area  41  to the second area  42  has been carried out. 
         [0064]    In a case that the item shifting operation from the first area  41  to the second area  42  has been carried out (YES at step S 310 ), at step S 320 , the CPU  11  shifts the item to be shifted (hereinafter, also called as an “item A”), from the first area  41  to the second area  42 . Accordingly, the item A becomes the “selected item”. Thereafter, the CPU  11  executes a basic-sub processing (previous selection cancellation processing) at step S 330 . The basic sub-processing is a processing for returning an item which was originally displayed in the second area  42  and which belongs to the setting item same as that of the item A to the first area  41 , when the item A is shifted from the first area  41  to the second area  42 . 
         [0065]    Concrete contents of the basic sub-processing are shown in  FIG. 7 . To start with, at step S 610 , the CPU  11  acquires the number of items (hereinafter, also called as “the number of belonging items”) H of a setting item to which the item A belongs (hereinafter, also called as “belonged setting item G”). 
         [0066]    As the CPU  11  acquires the number of belonging items H of the belonged setting item G, at step S 620 , the CPU  11  sets “1” to a belonged setting item element number h. In the embodiment, numbers starting from 1 are assigned to items belonging to each of the setting items. For instance, in a case of the color type, “1” is assigned to “monochrome”, “2” is assigned to “gray”, and “3” is assigned to “color”. The belonged setting item element number h is used to specify a predetermined item in the belonged setting item G. 
         [0067]    At step S 630 , the CPU  11  acquires the number of items N displayed in the second area  42  (hereinafter, also called as the “number of items in the second area”). At step S 640 , the CPU  11  sets “1” to a second-area element number n. The second-area element number n is a number for specifying one of the items displayed in the second area  42 . In the embodiment, numbers 1, 2, 3, . . . are assigned to the items displayed in the second area  42  in order from a top of the second area  42 . 
         [0068]    At step S 650 , the CPU  11  makes a judgment of whether or not the h th  item (h numbered item) of the belonged setting item G and the n th  item displayed in the second area  42  are same. In a case that a judgment is made that the h th  item and the n th  item are same (YES at step S 650 ), at step S 660 , the CPU  11  shifts the n th  item in the second area  42  to the first area  41 . In other words, the CPU  11  terminates the selection state of the n th  item, and sets the n th  item as a “selectable item”. In a case that a judgment is made that the h th  item and the n th  item are not same (NO at step S 650 ), the CPU  11  increments the second-area element number n by 1 at step S 670 , and at S 680 , the CPU  11  makes a judgment of whether or not the number of items N in the second area is greater than the second-area element number n at the current point of time. In a case that the second-area element number n is not greater than the number of items N in the second area (NO at step S 680 ), the process returns to step S 650 . In a case that the second-area element number n is greater than the number of items N in the second area (YES at step S 680 ), the CPU  11  increments the belonged setting item element number h by 1 at step S 690 , and step S 700 , the CPU  11  makes a judgment of whether or not the belonged setting item element number h is greater than the number of belonging items H. 
         [0069]    In a case that the belonged setting item element number h is not greater than the number of belonging items H (NO at step S 700 ), the process returns to step S 640 . In a case that the belonged setting item element number h is greater than the number of belonging items H (YES at step S 700 ), the CPU  11  terminates the basic sub-processing, and the process advances to step S 340  (refer to  FIG. 6A ). 
         [0070]    At step S 340 , the CPU  11  makes a judgment of whether or not there exists another exclusive item which is exclusive to the item which has been shifted from the second area  42  to the first area  41  by the basic sub-processing at step S 330 . Moreover, in a case that there is no exclusive item (NO at step S 340 ), the process advances to step S 360 , and in a case that there is another exclusive item (YES at step S 340 ), the process advances to step S 350 , and the CPU  11  executes a third sub-processing (non-selectable item cancellation processing). The third sub-processing is a processing for returning an item which is displayed in the third area  43  and which is freed from the non-selectable state (an item having no exclusive item, which is exclusive to the item, in the second area  42 ) to the first area  41 . 
         [0071]    Concrete contents of the third sub-processing are shown in  FIGS. 10A and 10B . Firstly, at step S 910 , the CPU  11  acquires the number of items (hereinafter, also called as “the number of items in the third area”) M displayed in the third area  43 . At step S 915 , the CPU  11  sets “1” to a third-area element number m. The third-area element number m is a number for specifying one of the items displayed in the third area  43 . In the embodiment, the numbers 1, 2, 3, . . . are assigned to the items displayed in the third area  43  in order from the top of the third area  43 . 
         [0072]    At step S 920 , the CPU  11  acquires the number of exclusive items J exclusive to the m th  item (hereinafter, also called as “item Z”) in the third area  43 . At step S 925 , the CPU  11  sets “1” to an exclusive item element number j. The exclusive item element number j is a number for specifying one of the exclusive items which are exclusive to the item Z. In the embodiment, numbers starting from 1 are assigned to the exclusive items for each item displayed in the third area  43 . 
         [0073]    At step S 930 , the CPU  11  acquires the number of items N displayed in the second area  42  (the number of items in the second area). At step S 935 , the CPU  11  sets “1” to the second-area element number n. At step S 940 , the CPU  11  makes a judgment of whether or not the j th  exclusive item from among the exclusive items with respect to the m th  item Z in the third area  43  and the n th  item displayed in the second area  42  are same. Here, in a case that a judgment is made that the j th  exclusive item and the n th  item are same (YES at step S 940 ), the m th  item Z is to be maintained as a “non-selectable item”. Therefore, at step S 970 , the third-area element number m is incremented by 1 in order to judge the subsequent m+1 th  item Z. 
         [0074]    At step S 975 , the CPU  11  makes a judgment of whether or not the third-area element number m is greater than the number of items M displayed in the third area  43  at the current point of time. In a case that the third-area element number m is not greater than the number of items M displayed in the third area  43  (NO at step S 975 ), the process returns to step S 920 . In a case that the third-area element number m is greater than the number of items M displayed in the third area  43  (YES at step S 975 ), the CPU  11  terminates the third sub-processing, and the process advances to step S 360  (refer to  FIG. 6A ). 
         [0075]    In a case that a judgment is made that the j th  exclusive item and the n th  item are not same (NO at step S 940 ), the CPU  11  increments the second-area element number n by  1  at step S 945 , and at step S 950 , the CPU  11  makes a judgment of whether or not the second-area element number n is greater than the number of items N in the second area  42 . In a case that the second-area element number n is not greater than the number of items N in the second area  42  (NO at step S 950 ), the process returns to step S 940 . In a case that the second-area element number n is greater than the number of items N in the second area  42  (YES at step S 950 ), the CPU  11  increments the exclusive item element number j by 1 at step S 955 , and at step S 960 , the CPU  11  makes a judgment of whether or not the exclusive item element number j is greater than the number of exclusive items J at the current point of time. In a case that the exclusive item element number j is not greater than the number of exclusive items J (NO at step S 960 ), the process returns to step S 930 . 
         [0076]    In a case that the exclusive item element number j is greater than the number of exclusive items J (YES at step S 960 ), it means that all the exclusive items with respect to the item Z are confirmed not being displayed in the second area  42 . Therefore, in this case, at step S 965 , the CPU  11  shifts that item Z from the third area  43  to the first area  41 . In other words, the item Z is released from the non-selectable state and the item Z is set as a “selectable item”. After step S 965 , the process advances to step S 970  onward. As the CPU  11  terminates the third sub-processing, the process advances to step S 360  (refer to  FIG. 6A ). 
         [0077]    At step S 360 , the CPU  11  makes a judgment of whether or not there exists another exclusive item which is exclusive to the item A that has been newly selected. Moreover, in a case that there is no exclusive item which is exclusive to the item A (NO at step S 360 ), the CPU  11  terminates the setting-operation receiving processing. In a case that there is another exclusive item which is exclusive to the item A (YES at step S 360 ), the process advances to step S 370 , and the CPU  11  executes a first sub-processing (first exclusive-item shifting processing). The first sub-processing is a processing for shifting an item which is exclusive to the item A newly shifted to the second area  42 , to the third area  43  as an “non-selectable item”, in a case that the item exclusive to the item A is displayed in the first area  41 . 
         [0078]    Concrete contents of the first sub-processing are shown in  FIGS. 8A and 8B . Firstly, at step S 710 , the CPU  11  acquires the number of items N displayed in the second area  42  (the number of items in the second area). At step S 715 , the CPU  11  sets “1” to the second-area element number n. At step S 720 , the CPU  11  acquires the number of exclusive items J which are exclusive to the n th  item (hereinafter, also called as “item X”) in the second area  42 . At step S 725 , the CPU  11  sets “1” to the exclusive item element number j. 
         [0079]    At step S 730 , the CPU  11  acquires the number of items K displayed in the first area  41  (hereinafter, also called as “the number of items K in the first area”). At step S 735 , the CPU  11  sets “1” to a first-area element number k. The first-area element number k is a number for specifying one of the items normally displayed in the first area  41 . In the embodiment, numbers 1, 2, 3, . . . are assigned to the items normally displayed in the first area  41  in order from the top (in order from left for a plurality of items in a same setting item) of the first area  41 . 
         [0080]    At step S 740 , the CPU  11  makes a judgment of whether or not the j th  exclusive item from among the exclusive items with respect to the n th  item X in the second area  42  and the k th  item displayed in the first area  41  are same. In a case that the j th  exclusive item and the k th  item are same (YES at step S 740 ), the CPU  11  shifts the k th  item in the first area  41  to the third area  43  at step S 745 . In other words, the CPU  11  sets the k th  item as a “non-selectable item”. In a case that a judgment is made that the j th  exclusive item and the k th  item are not same (NO at step S 740 ), the process advances to step S 750 . 
         [0081]    At step S 750 , the CPU  11  increments the first-area element number k by 1. At step S 755 , the CPU  11  makes a judgment of whether or not the first-area element number k is greater than the number of items K in the first area at the current point of time. In a case that the first-area element number k is not greater than the number of items K in the first area (NO at step S 755 ), the process returns to step S 740 . In a case that the first-area element number k is greater than the number of items K in the first area (YES at step S 755 ), the CPU  11  increments the exclusive item element number j by 1 at step S 760 , and at step S 765 , the CPU  11  makes a judgment of whether or not the exclusive item element number j is greater than the number of exclusive items J at the current point of time. In a case that the exclusive item element number j is not greater than the number of exclusive items J (NO at step S 765 ), the process returns to step S 730 . In a case that the exclusive item element number j is greater than the number of exclusive items J (YES at step S 765 ), the CPU  11  increments the second-area element number n by 1 at step S 770 , and at step S 775 , the CPU  11  makes a judgment of whether or not the second-area element number n is greater than the number of items N in the second area at the current point of time. In a case that the second-area element number n is not greater than the number of items N in the second area (NO at step S 775 ), the process returns to step S 720 . In a case that the second-area element number n is greater than the number of items N in the second area (YES at step S 775 ), the CPU  11  terminates the first sub-processing. 
         [0082]    At step S 310  of the setting-operation receiving processing in  FIG. 6A , in a case that the item shifting operation from the first area  41  to the second area  42  has not been carried out (NO at step S 310 ), at step S 380 , the CPU  11  makes a judgment of whether or not an item shifting operation from the second area  42  to the first area  41  (an operation as exemplified in  FIG. 4A ) has been carried out by the user. In a case that the item shifting operation from the second area  42  to the first area  41  has been carried out (YES at step S 380 ), the process advances to step S 390 , and the CPU  11  shifts the item to be shifted (hereinafter, also called as an “item B”) from the second area  42  to the first area  41 . In other words, the CPU  11  returns the item B, which had been displayed as a “selected item” in the second area  42 , as a “selectable item” to display normally. 
         [0083]    Thereafter, at step S 400 , the CPU  11  makes a judgment of whether or not there is an initial-value setting item in the setting item to which the item B belongs (belonged setting item G). The initial-value setting item is an item to which the second area is set as an initial-display position in the initial-display area presetting table shown in  FIG. 2C . In a case that at step S 400 , a judgment is made that there is no initial-value setting item in the belonged setting item G to which the item B belongs (NO at step S 400 ), the process advances to step S 430 , and in a case that a judgment is made that there is an initial-value setting item in the belonged setting item G (YES at step S 400 ), at step S 410 , the CPU  11  shifts the initial-value setting item of the setting item G to the second area  42  as the “selected item”. In other words, the CPU  11  replaces the item B with the initial-value setting item and displays the initial-value setting item in the second area  42 . 
         [0084]    The item to be displayed in the second area  42  instead of item B is not restricted to the initial-value setting item. For instance, an item (an item belonging to the same setting item G) which had been displayed in the second area  42  immediately before the item B was displayed in the second area  42  may be displayed once again in the second area  42 , or in a case that the previous setting contents are saved in the setting file, an item which had been displayed in the second area  42  when the previous operation was terminated may be displayed in the second area  42 . 
         [0085]    After the processing at step S 410 , at step S 420 , the CPU  11  executes the first sub-processing (first exclusive-item shifting processing). The first sub-processing is a processing shown in  FIGS. 8A and 8B , and concrete contents of the first sub-processing are as already been mentioned. As a result of shifting the item from the first area  41  to the second area  42  by the processing at step S 410 , there is a possibility that the item that has been shifted to the second area  42  and another item in the first area  41  that can be selected become mutually exclusive. In that case, it is necessary to shift the exclusive item from the first area  41  to the third area  43  as an “non-selectable item”. For realizing the shifting of the exclusive item, the CPU  11  executes the first sub-processing at step S 420 . 
         [0086]    After execution of the first sub-processing at step S 420 , at step S 430 , the CPU  11  executes the third sub-processing (non-selectable item cancellation processing). The third sub-processing is a processing shown in  FIGS. 10A and 10B , and concrete contents thereof are as already been mentioned. As a result of shifting the item B from the second area  42  to the first area  41  by the processing at step S 390 , there is a possibility that there is an item which is displayed in the third area and which is freed from the non-selectable state (an item, having no exclusive item, which is exclusive to the item, in the second area  42 ). In such case, it is necessary to return the item displayed in the third area  43  to the first area  41  as a “selectable item”. For realizing the return of the item, the CPU  11  executes the third sub-processing at step S 430 . 
         [0087]    At step S 380 , in a case that the item shifting operation from the second area  42  to the first area  41  has not been carried out (NO at step S 380 ), at step S 440 , the CPU  11  makes a judgment of whether or not an item shifting operation from the third area  43  to the second area  42  (shifting operation as exemplified in  FIG. 4B ) has been carried out. 
         [0088]    In a case that the item shifting operation from the third area  43  to the second area  42  has not been carried out (NO at step S 440 ); the CPU  11  terminates the setting-operation receiving processing. In a case that the item shifting operation from the third area  43  to the second area  42  has been carried out (YES at step S 440 ), the process advances to step S 450 , and the CPU  11  shifts the item to be shifted (hereinafter, also called as an “item C”) from the third area  43  to the second area  42  as the “selected item”. 
         [0089]    Moreover, at step S 460 , the CPU  11  executes the first sub-processing (first exclusive-item shifting processing). The first sub-processing is a processing shown in  FIGS. 8A and 8B , and concrete contents thereof are as already been mentioned. As a result of shifting the item C from the third area  43  to the second area  42  by the processing at step S 450 , there is a possibility that the item C and an item which is displayed in the first area  41  as the selectable item become mutually exclusive. In such case, it is necessary to shift the item which is displayed in the first area  41  and which is exclusive to the item C to the third area  43  as a “non-selectable item”. For realizing the shifting of the item from the first area  41  to the third area  43 , the CPU  11  executes the first sub-processing at step S 460 . 
         [0090]    After execution of the first sub-processing at step s 460 , at step S 470 , the CPU  11  executes a second sub-processing (second exclusive-item shifting processing). The second sub-processing is a processing for shifting an item which is exclusive to the item C shifted to the second area  42  to the third area  43  as a “non-selectable item”, in a case that the item exclusive to the item C is in the same second area  42 . Concrete contents of the second sub-processing are shown in  FIG. 9 . Firstly, at step S 810 , the CPU  11  acquires the number of exclusive items J which are exclusive to the item C shifted from the third area  43  to the second area  42  (hereinafter, also called as a “new item B”). At step S 815 , the CPU  11  sets “1” to the exclusive item element number j. At step S 820 , the CPU  11  acquires the number of items N displayed in the second area  42 . At step S 825 , the CPU  11  sets “1” to the second-area element number n. 
         [0091]    At step S 830 , the CPU  11  makes a judgment of whether or not the j th  exclusive item with respect to the new item B, and the n th  item displayed in the second area  42  are same. Here, in a case that a judgment is made that the j th  exclusive item and the n th  item are same (YES at step S 830 ), at step S 835 , the CPU  11  shifts the n th  item in the second area  42  to the third area  43  as a “non-selectable item”. After the processing at step S 835 , or in a case that a judgment is made that the j th  exclusive item and the n th  item are not same (NO at step S 830 ), the process advances to step S 840 . 
         [0092]    At step S 840 , the CPU  11  increments the second-area element number n by 1, and at step S 845 , the CPU  11  makes a judgment of whether or not the second-area element number n is greater than the number of items N in the second area  42  at the current point of time. In a case that the second-area element number n is not greater than the number of items N in the second area  42  (NO at step S 845 ), the process returns to step S 830 . In a case that the second-area element number n is greater than the number of items N in the second area  42  (YES at step S 845 ), the CPU  11  increments the exclusive-item element number j by 1 at step S 850 , and at step S 855 , the CPU  11  makes a judgment of whether or not the exclusive-item element number j is greater than the number of exclusive items J at the current point of time. In a case that the exclusive-item element number j is not greater than the number of exclusive items J (NO at step S 855 ), the process returns to step S 820 . In a case that the exclusive-item element number j is greater than the number of exclusive items J (YES at step S 855 ), the CPU  11  terminates the second sub-processing, and the process shifts to the third sub-processing (non-selectable item cancellation processing) of step S 480  (refer to  FIG. 6C ). 
         [0093]    The third sub-processing of step S 480  is a processing shown in  FIGS. 10A and 10B , and concrete contents thereof are as already been mentioned. As a result of shifting the item in the second area  42  to the third area  43  by the second sub-processing at step S 470 , there is a possibility that these is an item which had been displayed in the third area  43  and which is exclusive to the item shifted to the third area  43  (an item having no exclusive item displayed in the second area  42 ). In that case, it is necessary to return the item in the third area  43  having no exclusive item displayed in the second area  42 , to the first area  41  as a “selectable item”. For realizing the return of the item, the CPU  11  executes the third sub-processing at step S 480 . As the CPU  11  finishes the third sub-processing, the setting-operation receiving processing is terminated. 
         [0094]    According to the information processing system  1  described heretofore, as the user selects a desired item (parameter) from the first area  41 , another item which is exclusive to the selected item by the user is displayed in the third area  43  as the “non-selectable setting item”. Therefore, in a case that there is another item which is exclusive to the selected item, the user is able to know easily and specifically that there is an item which is exclusive to the selected item. Therefore, the usability at the time of selecting the item by the user is improved. 
         [0095]    Moreover, as it has been mentioned above, shifting of the item from the second area  42  to the first area  41 , and shifting of the item from the third area  43  to the second area  42  are also possible. Besides, in a case that there is a new item which cannot be selected by such shifting, that item is shifted to the third area  43 . Conversely, in a case that the item which had been displayed in the third area  43  is freed from the non-selectable state, the item is shifted to the first area  41 . Accordingly, every time the operation of shifting the item is carried out, the user is capable of knowing easily visually, as to what item has been selected, what item cannot be selected, and what item can be selected newly at the current point of time. 
       Modified Embodiments 
       [0096]    Embodiments of the present invention are not restricted to the embodiment described above, and it is needless to mention that it is possible to have various embodiments within the technical scope of the present invention. For example, the initial screen (default state) shown in  FIG. 2A  is merely an example, and it can be determined appropriately as to which item in the initial screen is to be set as a “selected item”. Moreover, each setting item and each item (parameter) shown in  FIG. 2  are merely examples. 
         [0097]    Moreover, the exclusive-relationship table shown in  FIG. 2B  is merely an example, and it can be determined appropriately as to which items are to be mutually exclusive according to constraints of software and hardware. 
         [0098]    Furthermore, in the embodiment described above, an example of mouse operation has been cited as a user operation at the time of shifting an item on the scan setting screen. However, the mouse operation is merely an example, and an arrangement may be made such that shifting by a keyboard input is possible, or shifting by drag-and-drop operation on a touch panel is possible. Moreover, an arrangement may be made such that an item is shifted by an operation other than the drag-and-drop operation. Furthermore, an arrangement may be made such that the scan-setting screen is displayed on the operation and display section  24  of the MFP  3 , and selection of item is carried out similarly as it has been described above.
A display control apparatus includes a control section which controls a display to display contents in a first display area, a second display area, and a third display area on the display. The control section is configured to: display at least one setting value in the first display area for each of a plurality of setting items; allow a user to select one of the at least one setting value in a particular setting item; receive a user's selection of the setting value for each of the setting items; display the selected setting value in the second display area in receipt of the user's selection; determine whether there is an exclusive setting value in the setting values displayed in the first display area and belonging to any setting item other than the particular setting item, the exclusive setting value being inadequate to be selected with the selected setting value.