Abstract:
A display device includes a display unit, first storing unit, first display control unit, second display control unit, first transition unit, second transition unit, and marking unit. The display unit includes a first portion and a second portion. The first storing unit stores title strings for a plurality of screen images including a base screen image and being arranged hierarchically from the base screen image along a screen navigation path starting from the base screen image. The first display control unit displays a first screen image on the first portion. The second display control unit displays a navigation string on the second portion. The navigation string includes at least one of the title strings corresponding to at least one of the screen images which is positioned in a part of the screen navigation path from the base screen image to the first screen image. The marking unit attaches a mark to one of the title string corresponding to a third screen image of a higher hierarchical level than the first screen image and included in the navigation string in order to distinguish the title string attached with the mark from the other title string. The first transition unit changes the first screen image displayed on the first portion to a second screen image of a lower hierarchical level than the first screen image when a user performs a prescribed selection, thereby displaying the second screen image on the first portion. The second transition unit changes the first screen image to a third screen image when the user performs a reverse transition operation, thereby displaying the third screen image on the first portion.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority from Japanese Patent Application No. 2009-108972 filed Apr. 28, 2009. The entire content of this priority application is incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    The present invention relates to a display device for displaying a setup screen with a screen navigation path. 
       BACKGROUND 
       [0003]    A multifunction peripheral is well known in the art as a single device capable of implementing a plurality of functions, such as a facsimile function, printer function, scanner function, and copier function. The multifunction peripheral allows a user to modify various setting items, such as resolution, density, and zoom percentage. The user can execute a desired operation on the multifunction peripheral after modifying the setting values as desired. 
         [0004]    For example, the user may follow the procedure below to modify setting values for the multifunction peripheral. First, the multifunction peripheral displays a setup menu screen in a display panel provided on the multifunction peripheral. The menu screen includes various choices for each function of the multifunction peripheral, such as facsimile setup and scanner setup, as well as a general setup selection. When the user selects one of the choices listed in the menu, the multifunction peripheral changes the display on the display panel to a list of setting items related to the selected function. 
         [0005]    When the user selects one of the setting items from the displayed list, the multifunction peripheral changes the display on the display panel to a modification screen in which the user can modify the value assigned to the setting item. While the modification screen is displayed, the user may input or modify the value assigned to the setting item as desired. 
         [0006]    As the user performs operations to navigate through the prepared screens in this way, data indicating the path that the user has taken to arrive at the current screen may also be displayed in the display panel together with the current screen. One conventional format for displaying this path is called “breadcrumbs.” 
         [0007]    Breadcrumbs (or “breadcrumb trail”) is a format for displaying the name of each screen that the user has navigated through to arrive at the current screen in the order displayed, such as in the example “Menu screen&gt;Facsimile setup&gt;Resolution.” Through the breadcrumbs displayed with each screen, the user can determine to which function and to which setting item the current screen is related. 
       SUMMARY 
       [0008]    During the process of navigating through various screens through repeated operations, the user at times may wish to cancel settings made previously or to navigate to a setup screen related to a different function. To provide for such situations, the control panel or the like of the multifunction peripheral is sometimes provided with a Return key and a Cancel key, for example, allowing the user to input instructions in order to navigate from the current screen to a screen in a higher hierarchical level. 
         [0009]    However, the user may be inconvenienced when performing operations to navigate to screens in higher levels because often the user cannot correctly identify the screen that will be displayed when performing such operations prior to executing the operations. For example, if the user presses the Cancel key with the aim of navigating to a screen one level higher, the display may actually be returned to a screen at a higher level than the user expected, forcing the user to repeat several operations. 
         [0010]    In view of the foregoing, it is an object of the present invention to provide a user-friendly display device that enables the user to understand in advance what information will be displayed in a display section when a reverse transition operation (e.g., a return or cancel operation) is performed. 
         [0011]    In order to attain the above and other objects, the invention provides a display device. The display device includes a display unit, a first storing unit, a first display control unit, a second display control unit, a marking unit, a first transition unit, and a second transition unit. The display unit includes a first portion and a second portion. The first storing unit stores a plurality of title strings corresponding to a plurality of screen images including a base screen image and being arranged hierarchically from the base screen image along a screen navigation path starting from the base screen image. The first display control unit displays a first screen image on the first portion. The second display control unit displays a navigation string on the second portion based on screen navigation data, the screen navigation data indicating relationships between the screen images. The navigation string includes at least one of the title strings corresponding to at least one of the screen images which is positioned in a part of the screen navigation path from the base screen image to the first screen image. The marking unit attaches a mark to one of the title strings corresponding to a third screen image of a higher hierarchical level than the first screen image and included in the navigation string in order to distinguish the title string attached with the mark from the other title strings. The first transition unit changes the first screen image displayed on the first portion to a second screen image of a lower hierarchical level than the first screen image when a user performs a prescribed selection, thereby displaying the second screen image on the first portion. The second transition unit changes the first screen image to the third screen image when the user performs a reverse transition operation, thereby displaying the third screen image on the first portion. 
         [0012]    According to another aspect, the present invention provides a method for displaying one of a plurality of screen images on a display unit of a display device. The plurality of screen images includes a base screen image and being arranged hierarchically from the base screen image along a screen navigation path starting from the base screen image. The method includes, (a) displaying a first screen image on a first portion of the display unit based on screen navigation data, the screen navigation data indicating relationships between the screen images, (b) displaying a navigation string on a second portion of the display unit, the navigation string including at least one of title strings corresponding to at least one of the screen images which is positioned in a part of the screen navigation path from the base screen image to the first screen image, (c) attaching a mark to one of the title strings corresponding to a third screen image of a higher hierarchical level than the first screen image and included in the navigation string in order to distinguish the title string attached with the mark from the other title strings, (d) changing the first screen image displayed on the first portion to a second screen image of a lower hierarchical level than the first screen image when a user performs a prescribed selection, thereby displaying the second screen image on the first portion, and (e) changing the first screen image to the third screen image when the user performs a reverse transition operation, thereby displaying the third screen image on the first portion. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The particular features and advantages of the invention as well as other objects will become apparent from the following description taken in connection with the accompanying drawings, in which: 
           [0014]      FIG. 1  is a schematic diagram showing an electrical construction of a multifunction peripheral according to an embodiment of the present invention; 
           [0015]      FIG. 2  is an explanatory diagram showing a sample configuration of a screen management table; 
           [0016]      FIG. 3  is an explanatory diagram showing a sample configuration of a screen transition table; 
           [0017]      FIG. 4A  is a “Mode Timer” screen having a Return button displayed on a LCD of the multifunction peripheral; 
           [0018]      FIG. 4B  is a “General Setup” screen having the Return button displayed on the LCD; 
           [0019]      FIG. 4C  is the “General Setup” screen having a Cancel button; 
           [0020]      FIG. 4D  is a “Menu” screen having a grayed out Return button; 
           [0021]      FIG. 5  is a flowchart showing a setup screen display process; 
           [0022]      FIG. 6  is a flowchart showing the setup screen display process following the flowchart of  FIG. 5 ; and 
           [0023]      FIG. 7  is an enlarged view of a rasterized breadcrumbs character string. 
       
    
    
     DETAILED DESCRIPTION 
       [0024]    A multifunction peripheral (MFP)  1  according to an embodiment of the invention will be described while referring to the accompanying drawings wherein like parts and components are designated by the same reference numerals to avoid duplicating description. 
         [0025]    The MFP  1  is a multifunction peripheral having multiple functions, including a facsimile function and a printer function. The MFP  1  allows a user to modify values of various setting items defining operating conditions and the like for each function. The MFP  1  has a plurality of setup screens by which the user can modify values for each setting item. 
         [0026]    As shown in  FIG. 1 , the MFP  1  includes a CPU  11 , a ROM  12 , a RAM  14 , an EEPROM  15 , a telephone/fax unit  19 , a scanner  22 , a printer  25 , an operation key  26 , a LCD  27 , and a touch panel  28 . These are interconnected with a bus line  29  with each other. Although not shown in the drawings, the MFP  1  further includes an interface for connecting with a personal computer and LAN and other components. 
         [0027]    The ROM  12  is a nonvolatile memory in which a control program  12   a , a screen management table  12   b , and a screen transition table  12   c  are stored. The CPU  11  executes a setup screen display process shown in  FIGS. 5 and 6  based on the control program  12   a . The screen management table  12   b  and the screen transition table  12   c  are pre-stored in the ROM  12  during the manufacturing stage of the MFP  1 . The tables  12   b  and  12   c  will be described later with reference to  FIGS. 2 and 3 . 
         [0028]    The RAM  14  is a volatile memory for temporarily storing data. The EEPROM  15  is a nonvolatile memory for storing various setting items and fixed values, and retains data even after power is turned OFF. 
         [0029]    The LCD  27  has an LCD panel (not shown). The MFP  1  displays prepared setup screens in the LCD panel of the LCD  27  as needed. These setup screens will be described later with reference to  FIG. 3 . The touch panel  28  is a type of input device and is disposed parallel and in proximity to a display surface of the LCD panel. When the user touches the display surface of the LCD panel with a finger or the like, the touch panel  28  detects the position of the finger with respect to the LCD panel. 
         [0030]    The MFP  1  can switch between a print mode for printing, a facsimile mode for receiving and sending a facsimile, and a setup mode for changing values for the setting items. 
         [0031]      FIG. 2  shows a sample configuration of the screen management table  12   b . The screen management table  12   b  defines a hierarchical level, a screen title, and a title ID for each setup screen that can be displayed in the LCD panel of the LCD  27  for accepting user selections. The MFP  1  organizes and manages the plurality of the setup screens in hierarchical levels based on the screen management table  12   b . When the user performs a prescribed selection operation in the LCD panel displaying a higher-level setup screen, the MFP  1  changes the display in the LCD panel to a lower-level setup screen. 
         [0032]    A “level number” is a value indicating the hierarchical level to which each setup screen belongs. In the example shown in  FIG. 2 , each of the setup screens belongs to one of first through fifth levels. The screen title is configured of a descriptive character string by which the content of the setup screen can be discerned. One screen title is uniquely associated with each setup screen. The title ID is a resource ID in the form of a character string. One title ID is uniquely assigned to each screen title and is used to create a breadcrumbs  35   b  ( FIG. 4A ), as will be described later. 
         [0033]    As shown in  FIG. 2 , a menu screen having a screen title “Menu” is defined in the screen management table  12   b  as a setup screen in the first level (hierarchical level  1 ). Setup screens defined for the second level (hierarchical level  2 ) directly beneath the first level are a general setup screen having a screen title “General Setup” and a network setup screen having a screen title “Network.” Similarly, the screen management table  12   b  defines setup screens belonging to the third level (hierarchical level  3 ) directly beneath the second level, setup screens belonging to the fourth level (hierarchical level  4 ) positioned directly beneath the third level, and setup screens belonging to the fifth level (hierarchical level  5 ) positioned directly beneath the fourth level. 
         [0034]    The MFP  1  transitions between the setup screens from the top hierarchical level to each lower level in sequence. For example, in order to display a TCP/IP setup screen (having a screen title “TCP/IP”) belonging to the fourth level, the MFP  1  first displays the menu screen of the first level, then displays the network setup screen of the second level, then displays a LAN setup screen (having a screen title “WLAN”) of the third level, and finally displays the TCP/IP setup screen of the fourth level. 
         [0035]    The MFP  1  according to the embodiment changes the display on the LCD  27  so as to navigate to setup screens not only in order from higher levels to lower levels, but also in the direction from lower levels to higher levels when the user performs a prescribed operation. 
         [0036]      FIG. 3  shows a sample configuration of the screen transition table  12   c . The screen transition table  12   c  defines destination setup screens and the like for cases in which the display is changed in a direction from lower levels to higher levels. Specifically, the screen transition table  12   c  stores correlations between hierarchical levels, screen titles, events, and destination screen titles. 
         [0037]    The “hierarchical level” and the “screen title” are identical to those stored in the screen management table  12   b  and, hence, a description of these elements will not be repeated here. 
         [0038]    The events stored in the screen transition table  12   c  may be either “Return button pressed” or “Cancel button pressed.” When one of the events stored in the screen transition table  12   c  occurs, i.e., when one of either a Return button  36   a  or a Cancel button  36   b  (described later) is pressed, the MFP  1  changes the setup screen currently displayed on the LCD  27  to a setup screen in a higher hierarchical level. This process will be described later in greater detail with reference to  FIGS. 4A-4D . 
         [0039]    A “destination screen title” is a screen title for a destination setup screen that is displayed when an event occurs while a setup screen corresponding to an associated “screen title” is displayed. For example, an event associated with a screen title “Mode Timer” in the third level is “Return button pressed” and a destination screen title is “General Setup” for a setup screen belonging to the second level. Accordingly, if the event “Return button pressed” occurs while a setup screen corresponding to “Mode Timer” is displayed, the MFP  1  changes the currently displayed third-level setup screen to the second-level setup screen corresponding to “General Setup.” 
         [0040]    Similarly, if the event “Cancel button pressed” occurs while a setup screen corresponding to “Reset Factory” is displayed, the MFP  1  changes the third-level setup screen having the screen title “Reset Factory” to the menu screen belonging to the first level, that is, two levels higher than the current level. 
         [0041]    Thus, when changing the display in a direction from a lower level to a higher level, in some cases the MFP  1  according to the embodiment returns to a setup screen one level above the current screen, and in other eases returns to a setup screen two levels or more above the current screen. The reasoning behind this is that the MFP  1  navigates to the most suitable setup screen based on a predicted sequence of operations that the user will perform after the display is changed to a higher level. However, this process is not useful to the user unless the user knows before actually performing the operation how many levels upward the MFP  1  navigates to reach the destination setup screen. 
         [0042]    Thus, the MFP  1  according to the embodiment is configured to display an indicator on the LCD  27  indicating the destination setup screen so that the user can identify in advance a setup screen to which the display will be returned when the user performs a prescribed operation. 
         [0043]    Images displayed in the LCD panel of the LCD  27  during the setup mode will be described.  FIGS. 4A-4D  shows screen images illustrating a sample transition of display on the LCD  27 . As shown in  FIG. 4A , the display area of the LCD panel includes a selection display area  32 , a screen description area  34 , and a Return button area  36 . 
         [0044]    A setup screen is drawn in the selection display area  32 . The setup screen includes various selections  33  that can be operated by the user to perform a selection. Each selection  33  is a graphic image that functions as a button by which the user can select a setup screen positioned one level below the current setup screen, or a setting value. Each selection  33  also includes a character string expressing either the screen title of a setup screen positioned one level below the level of the currently displayed setup screen, or a setting value to be set in association with the currently displayed setup screen. 
         [0045]    In the example shown in  FIG. 4A , a setup screen of the third level having the screen title “Mode Timer” is displayed in the selection display area  32 . This setup screen includes selections  33  depicting setting values that may be selected. When the user performs an operation to touch a selection  33  in the LCD panel, the MFP  1  stores a setting value associated with the touched selection  33  in the EEPROM  15 , for example. 
         [0046]    When the selections  33  depict screen titles for setup screens located one level below the current setup screen, the MFP  1  changes the display on the LCD  27  to the setup screen corresponding to the screen title in the selection  33  selected by the user. The operation to touch a selection  33  is equivalent to a “prescribed selection operation,” where the prescribed selection operation may comprise an operation to select one of the displayed selections  33  using the operating keys  26 , for example. 
         [0047]    The screen description area  34  includes a title display area  34   a  occupying the lower half thereof, and a breadcrumbs display area  34   b  occupying the upper half thereof. The title display area  34   a  is provided for displaying a screen title  35   a  for the setup screen currently displayed on the selection display area  32 . 
         [0048]    The breadcrumbs display area  34   b  serves to display the breadcrumbs  35   b . The breadcrumbs  35   b  is a character string formed by arranging the screen title corresponding to each setup screen that has been displayed up to the currently displayed setup screen in a single horizontal line in order of hierarchical level. In the example shown in  FIG. 4A , a character string formed by concatenating all screen titles displayed up to, but not including, the currently displayed setup screen of the third level (i.e., a screen title of the first level and a screen title of the second level) is displayed as the breadcrumbs  35   b . Based on the breadcrumbs  35   b , the user can determine a screen navigation path leading up to the currently displayed setup screen. 
         [0049]    The MFP  1  also adds a triangular separating character  35   c  to the head of each screen title in the breadcrumbs  35   b  for separating the screen titles. Based on the separating characters  35   c , the user can identify each screen title in the breadcrumbs  35   b  and, thus, can easily understand the screen navigation path. 
         [0050]    The Return button area  36  serves as a button that shifts the display in the selection display area  32  from the currently displayed setup screen to the setup screen belonging to a level higher than the level of the currently displayed setup screen. For example, if the currently displayed setup screen belongs to the third level and the user wishes to return to a setup screen in the first or second level, the user can navigate to this desired level by operating the Return button area  36 . An operation to touch the Return button area  36  corresponds to a “reverse transition operation.” The MFP  1  also draws a return icon, such as an arrow indicating a U-turn, or an “X” symbol in the Return button area  36 . The Return button area  36  having a return icon will be referred to as the Return button  36   a , while a Return button area  36  with an “X” symbol will be referred to as the Cancel button  36   b.    
         [0051]    Further, in order to indicate to the user what destination setup screen will be displayed if the user operates the Return button area  36 , the MFP  1  displays a separating character  35   c  in front of the screen title for the destination setup screen in the breadcrumbs  35   b  using a different format from the other separating characters  35   c . More specifically, the MFP  1  draws a return position marker  35   d  within only the separating character  35   c  added to the head of the screen title for the destination setup screen. Thus, this separating character  35   c  functions as an indicator indicating the destination setup screen of the reverse transition operation. 
         [0052]    In the screen image shown in  FIG. 4A , for example, the return position marker  35   d  is drawn only within the separating character  35   c  added to the head of the screen title “General Setup.” By viewing the breadcrumbs  35   b , the user can tell before operating the Return button area  36  that the display will change to the setup screen having the screen title “General Setup” when the user operates the Return button area  36 . If the user wishes to change to this setup screen after confirming the setup screen as the destination setup screen, the user simply presses the Return button area  36 . As a result, the MFP  1  changes the display to the screen shown in  FIG. 4B . 
         [0053]    In  FIG. 4B , the general setup screen belonging to the second level is displayed in the selection display area  32 . As shown in  FIG. 4B , the general setup screen includes various selections  33  and, when setting values are already stored in the EEPROM  15  or the like in association with these selections  33 , may display a setting description  37  next to the corresponding selection  33  that includes a character string expressing the setting value. 
         [0054]    By providing the return position marker  35   d  in the separating character  35   c , as described above, the MFP  1  of the embodiment enables the user to see in advance (i.e., prior to pressing the Return button area  36 ) which setup screen will be displayed when the user operates the Return button area  36 . Accordingly, the displays provided by the MFP  1  are user-friendly. Thus, the MFP  1  eliminates any surprise and regret the user may feel when the display shifts to a setup screen of an unexpected higher level as a result of operating the Return button area  36  without being aware of the destination setup screen, for example. 
         [0055]    Further, by adding the return position marker  35   d  to the separating character  35   c , the separating character  35   c  takes on two functions: separating screen titles within the breadcrumbs  35   b  and indicating the destination setup screen. Hence, the breadcrumbs  35   b  presents more information to the user without increasing the number of characters in the breadcrumbs  35   b . As a result, the MFP  1  can provide useful information for facilitating user operations by effectively utilizing the limited display area of the LCD  27 . 
         [0056]    The return position marker  35   d  is an icon or symbol that has the same design as the icon or symbol provided in the Return button area  36 . Here, “the same design” denotes a design that the user can identify as having the same shape, and does not require that the design corresponds exactly in terms of size and color. For example, when the “X” symbol is drawn in the Return button area  36 , as shown in  FIG. 4C , the MFP  1  also includes an “X” symbol in the separating character  35   c  as the return position marker  35   d . This display method is user-friendly because the user can directly grasp the significance of the separating character  35   c  provided with the return position marker  35   d , i.e., that the screen title set apart from other screen titles by the return position marker  35   d  indicates the destination setup screen that will be displayed when the Return button area  36  is operated. 
         [0057]    Further, the breadcrumbs  35   b  may be omitted from the display when the menu screen of the topmost level is displayed in the selection display area  32 , as shown in  FIG. 4D . In addition, the Return button area  36  may be grayed out when the menu screen is displayed to inform the user that the Return button area  36  cannot be operated at this time. 
         [0058]    Further, when the number of selections  33  is too large to be displayed in the selection display area  32  at one time, the MFP  1  may display a sidebar area  38  in the selection display area  32  as shown in  FIG. 4B . By operating the sidebar area  38 , the user can scroll through the selections  33  to reveal selections  33  outside the display area. 
         [0059]      FIGS. 5 and 6  are flowcharts illustrating steps in the setup screen display process. The MFP  1  periodically executes the setup screen display process when in the setup mode. 
         [0060]    In S 502  at the beginning of the setup screen display process, the CPU  11  attempts to acquire a screen navigation event. In S 504  the CPU  11  determines whether a screen navigation event was acquired. If not (S 504 : NO), then the CPU  11  returns to S 502 . 
         [0061]    However, if so (S 504 : YES), then in S 506  the CPU  11  acquires a hierarchical level f for a currently displayed setup screen. In S 508  the CPU  11  determines whether the screen navigation event acquired in S 502  indicates that the Cancel button  36   b  was pressed (operated). If so (S 508 : YES), then the CPU  11  advances to S 516 . 
         [0062]    However, if not (S 508 : NO), then in S 510  the CPU  11  determines whether the screen navigation event indicates that a selection  33  was pressed. If so (S 510 : YES), then the CPU  11  advances to S 516  described later. 
         [0063]    However, if not (S 510 : NO), then in S 512  the CPU  11  determines whether the screen navigation event indicates that the Return button  36   a  was pressed. If so (S 512 : YES), then the CPU  11  advances to S 516 . 
         [0064]    However, if not (S 512 : NO), then in S 514  the CPU  11  determines whether the screen navigation event indicates an instruction to end the setup screen display process. A positive determination is made if, for example, the user inputs an instruction to switch from the setup mode to another mode (S 514 : YES), the CPU  11  ends the setup screen display process. However, if not (S 514 : NO), then the CPU  11  returns to S 502  and repeats the above process. 
         [0065]    In S 516  the CPU  11  acquires a destination screen m corresponding to the screen navigation event. For example if the Cancel button  36   b  is pressed while a setup screen with the screen title “Reset Factory” is displayed (S 508 : YES), then in S 516  the CPU  11  references the screen transition table  12   c  (see  FIG. 3 ) and acquires the menu screen as the destination screen m. Similarly, if a selection  33  having the character string “TCP/IP” is pressed while the setup screen having the screen title “WLAN” is displayed (S 510 : YES), then in S 516  the CPU  11  references the screen management table  12   b  (see  FIG. 2 ) and acquires the TCP/IP setup screen (having the screen title “TCP/IP”) as the destination screen m. Similarly, if the Return button  36   a  was pressed while the setup screen having the screen title “WLAN” was displayed (S 512 : YES), then in S 516  the CPU  11  references the screen transition table  12   c  and acquires the setup screen having the screen title “Network” as the destination screen m. Although not indicated in the flowchart, if the pressed selection  33  corresponds to a setting value (see  FIG. 4A ), the CPU  11  performs a process to store the corresponding setting value in the EEPROM  15 . 
         [0066]    In S 518  the CPU  11  acquires title IDs from the screen management table  12   b  for setup screens from the first hierarchical level to the destination screen m and records these title IDs in a breadcrumbs ID. The breadcrumbs ID is a data array in which a single title ID may be recorded for each hierarchical level. The breadcrumbs ID is updated each time the displayed setup screen changes, and a breadcrumbs is created based on the breadcrumbs ID as described later. For example, if the destination screen m is the TCP/IP setup screen in the fourth level, the following data is saved in S 518  as the breadcrumbs ID: [1]ID00[2]ID90[3]ID91[4]ID93, where the numbers in “[ ]” correspond to the hierarchical levels and each character string starting with “ID” corresponds to the title ID recorded for the respective setup screen. In this case, the screen navigation path from the menu screen to the TCP/IP setup screen is indicated in a breadcrumbs as “&gt;Menu&gt;Network&gt;WLAN,” in the process described later, where the separating character  35   c  is denoted by the “&gt;” symbol in this specification. 
         [0067]    In S 520  the CPU  11  acquires a hierarchical level g of the destination screen m. In S 522  the CPU  11  determines whether the hierarchical level g is “1”. If not (S 522 : NO), then the CPU  11  advances to S 602  of  FIG. 6 . 
         [0068]    However, if so (S 522 : YES), then in S 524  the CPU  11  acquires a screen title for the destination screen m (the setup screen in the first level). In S 526  the CPU  11  initializes the breadcrumbs ID. In S 528  the CPU  11  records the title ID for the destination screen m in the breadcrumbs ID, and displays the screen title for the destination screen m in the title display area  34   a . In S 532  the CPU  11  displays (writes) images in areas other than the title display area  34   a . Specifically, the CPU  11  displays the destination screen m in the selection display area  32  and draws images in the Return button area  36  and sidebar area  38 , thereby changing the display on the LCD  27  to the setup screen in the level corresponding to the user&#39;s selection operation or reverse transition operation. Subsequently, the CPU  11  returns to S 502 . 
         [0069]    In S 602  of  FIG. 6 , the CPU  11  acquires the screen title of the destination screen m from the screen management table  12   b . In S 604  the CPU  11  writes the acquired screen title to the title display area  34   a.    
         [0070]    In S 606  the CPU  11  displays (writes) images in areas other than the screen description area  34 . Specifically, the CPU  11  writes the destination screen m in the selection display area  32  and images in the Return button area  36  and sidebar area  38 . If the event stored in the screen transition table  12   c  in association with the destination screen m is “Return button pressed,” then the CPU  11  writes the return icon representing the Return button  36   a  in the Return button area  36 . If the event stored in association with the destination screen m is “Cancel button pressed,” the CPU  11  writes the “X” symbol representing the Cancel button  36   b  in the Return button area  36 . 
         [0071]    In S 608  the CPU  11  acquires the breadcrumbs ID and in S 610  initializes the breadcrumbs character string S. The breadcrumbs character string S is data representing the breadcrumbs  35   b  displayed in the breadcrumbs display area  34   b  as character codes. 
         [0072]    In S 612  the CPU  11  references the screen transition table  12   c  to acquire the level number of the destination setup screen stored in association with the currently displayed setup screen as the destination that is displayed when the Return button is pressed (destination screen level r). For example, if the currently displayed setup screen has the screen title “Network,” the destination setup screen recorded in the screen transition table  12   c  for eases in which the Return button is pressed is the menu screen. Accordingly, the CPU  11  acquires the level number “1” for the menu screen as the destination screen level r. If “Return button pressed” is not stored in the screen transition table  12   c  as an event corresponding to the currently displayed setup screen, then in S 612  the CPU  11  acquires a null value as the destination screen level r. 
         [0073]    In S 614  the CPU  11  references the screen transition table  12   c  to acquire the level number of the destination setup screen recorded in association with the currently displayed setup screen for a “Cancel button pressed” event (destination screen level c). For example, if the currently displayed setup screen has the screen title “Reset Factory,” the setup screen stored as the destination for cases in which the Cancel button is pressed is the menu screen. Accordingly, the CPU  11  acquires the level number “1” for the menu screen as the destination screen level c. If “Cancel button pressed” is not stored as an event corresponding to the currently displayed setup screen, then in S 614  the CPU  11  acquires a null value as the destination screen level c. 
         [0074]    In S 616  the CPU  11  sets a variable i to “1” and in S 618  determines whether the variable i is smaller than the hierarchical level g of the currently displayed setup screen. If so (S 618 : YES), then in S 620  the CPU  11  determines whether the variable i is equivalent to the destination screen level r (i=r). If so (S 620 : YES), then in S 628  the CPU  11  adds data equivalent to the separating character  35   c  with the return icon as the return position marker  35   d  to the breadcrumbs character string S, and subsequently advances to S 630  described later. 
         [0075]    However, if not (S 620 : NO), then in S 622  the CPU  11  determines whether the variable i is equivalent to the destination screen level c (i=c). If so (S 622 : YES), then in S 626  the CPU  11  adds data equivalent to the separating character  35   c  with the “X” symbol as the return position marker  35   d  to the breadcrumbs character string S, and subsequently advances to S 630 . 
         [0076]    However, if not (S 622 : NO), then in S 624  the CPU  11  adds data equivalent to a standard separating character  35   c , that is, a separating character  35   c  that does not have a return position marker  35   d , to the breadcrumbs character string S, and subsequently advances to S 630 . 
         [0077]    In S 630  the CPU  11  acquires a title ID for a level i from the breadcrumbs ID and acquires a screen title corresponding to the title ID from the screen management table  12   b . In S 632 , the CPU  11  adds the acquired screen title to the breadcrumbs character string S. In S 634 , the CPU  11  increments the variable i by “1” and returns to S 618 . 
         [0078]    Through the above process, the MFP  1  can identify a setup screen that is the destination of a reverse transition operation based on the destination screen level r or c each time the setup screen on the LCD  27  changes, and the separating character  35   c  with the return position marker  35   d  can be displaced in front of a screen title of thus identified setup screen. 
         [0079]    When the CPU  11  determines in S 618  that the variable i is greater than or equal to the hierarchical level g (S 618 : NO), then in S 636  the CPU  11  sets the variable  to “ 1”. In S 638  the CPU  11  rasterizes the breadcrumbs character string S to generate raster data R. In S 640  the CPU  11  calculates a display width Ws corresponding to the length of the raster data R in the longitudinal direction. Since the breadcrumbs character string S is rasterized before being displayed as the breadcrumbs  35   b  in a subsequent process, the CPU  11  can acquire the length of the breadcrumbs  35   b  (i.e., the horizontal dimension of the character array) to be displayed in the breadcrumbs display area  34   b  by finding the length (display width Ws) of the rasterized breadcrumbs raster data R. 
         [0080]      FIG. 7  is an enlarged view of a breadcrumbs character string S that has been rasterized (raster data R). By rasterizing the breadcrumbs character string S, the CPU  11  acquires bitmap data representing the breadcrumbs  35   b  in an array of points (pixels). In the embodiment, the CPU  11  totals the number of pixels in the width direction required to display each character and space in order to calculate the display width Ws corresponding to the longitudinal length of the raster data R. 
         [0081]    The MFP  1  may also allow the user to set a desired size or font for the text to be displayed on the LCD  27 . In this case, in S 638  of  FIG. 6  the CPU  11  reads values for the text size and font set by the user and develops the breadcrumbs character string S into bitmap data based on these values. For some fonts, the width of each character may differ. With a proportional font, for example, the letter “U” shown in  FIG. 7  has a width of seven pixels, while the letters “M”, “E”, and “N” have respective widths of eight pixels. Further, in many cases the width of roman characters differs from the width of Chinese characters (kanji). Hence, the CPU  11  can acquire a more accurate display width Ws through a calculation based on the rasterized bitmap data than through a calculation simply based on the number of characters. 
         [0082]    Returning to  FIG. 6 , in s 642  the CPU  11  determines whether the entire raster data R can be displayed inside the breadcrumbs display area  34   b . That is, the CPU  11  determines whether the display width Ws is less than or equal to a predetermined width W, where the predetermined width W is a value equivalent to the number of pixels in the breadcrumbs display area  34   b  along the horizontal direction (longitudinal direction) thereof that can be used for displaying text. 
         [0083]    If so (S 642 : YES), then in S 648  the CPU  11  displays the breadcrumbs  35   b  in the breadcrumbs display area  34   b  based on the breadcrumbs character string S. 
         [0084]    However, if not (S 642 : NO), then in S 644  the CPU  11  updates the breadcrumbs character string S by deleting a screen title of the i th  level from the breadcrumbs character string S, in S 646  increments the variable i by “1”, and returns to S 638  to repeat the process described above. Once the CPU  11  determines that the display width Ws is less than or equal to the predetermined width W (S 642 : YES), then the CPU  11  rasterizes the breadcrumbs character string S and displays the rasterized breadcrumbs character string S as the breadcrumbs  35   b  (raster data R) updated earlier by deleting the screen title corresponding to the first (highest) level, or screen titles corresponding to setup screens in a plurality of upper levels including and continuous from the first level (S 648 ). Accordingly, the MFP  1  can present screen titles to the user with priority given to levels nearest the level of the currently displayed setup screen so that the user can quickly recognize in which level the currently displayed setup screen is positioned. Subsequently, the CPU  11  returns to S 502 . 
         [0085]    Through the setup screen display process described in  FIGS. 5 and 6 , each time the setup screen changes, the MFP  1  identifies a destination setup screen for a reverse transition operation and adds the separating character  35   c  having the return position marker  35   d  to a screen title in the breadcrumbs display area  34   b  corresponding to the destination setup screen. Hence, the MFP  1  always presents updated information indicating the destination setup screen that will be displayed if the reverse transition operation is performed. 
         [0086]    While the invention has been described in detail with reference to the embodiment thereof, it would be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention. 
         [0087]    For example, while the breadcrumbs  35   b  is displayed in one line in the embodiment described above, the breadcrumbs  35   b  may be displayed in multiple lines with line breaks therebetween. In this case, the predetermined width W compared with the display width Ws would be a value found by multiplying the horizontal width of the breadcrumbs display area  34   b  by the number of lines available for displaying the breadcrumbs  35   b.    
         [0088]    In the embodiment described above, the MFP  1  determines whether the breadcrumbs  35   b  will fit within the breadcrumbs display area  34   b  based on the display width Ws expressing the horizontal length of the breadcrumbs character string S after rasterization. However, the MFP  1  may be configured to determine whether the breadcrumbs  35   b  fits within the breadcrumbs display area  34   b  based on the number of characters in the breadcrumbs character string S. 
         [0089]    In the embodiment described above, the Return button area  36  displayed on the LCD  27  functions as a button for performing the reverse transition operation, but an Undo key or Cancel key provided in the operating keys  26  may be used to function as the operating key for the reverse transition operation. 
         [0090]    Further, while the return position marker  35   d  is displayed within the separating character  35   c  in the embodiment described above, these display elements may be displayed in separate display areas.