Patent Publication Number: US-2012030601-A1

Title: Information display control apparatus, information display control method, storage medium storing information display control program

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an information display control apparatus, an information display control method, and a storage medium storing an information display control program, which control information display on a display unit of a printer (an image forming apparatus), for example. Particularly, the present invention relates to the information display control apparatus, the information display control method, and the storage medium storing the information display control program, which displays a filename as the information. 
     2. Description of the Related Art 
     In general, a printer that has a function to print image data (an image file) recorded in a storage medium such as a USB memory as an image is provided with a display unit that displays a filename to specify an image file to be printed. When printing an image, a user selects an image file by designating a filename displayed on the display unit. Next, the user designates a required number of copies and prints the image. 
     Incidentally, many of such printers are equipped with the display units that can display 4 or 5 lines of information rather than conventional units that can display 1 or 2 lines of information in response to user&#39;s requests of improvement in operability. For example, an LCD panel of a graphical display system of a dot matrix (about 128×64 dots) is able to display 4 or 5 lines in which 10 through 20 characters are displayed per line. 
     Accordingly, a long filename cannot be displayed within one line of the display unit. Then, when a part of a filename is not displayed within a line on the display unit, a plurality of files having similar names may not be distinguished by parts of filenames displayed on the display unit. 
     On the other hand, Japanese Laid-Open Patent Publication (Kokai) No. 2009-163561 (JP 2009-163561A) discloses a technique to generate filenames that are easy to distinguish when displaying a plurality of filenames on the display unit. 
     The technique of JP 2009-163561A shortens a long filename to generate a new filename that is easily distinguished from other filenames. However, the original filename will be unclear when the filename is shortened. 
     SUMMARY OF THE INVENTION 
     The present invention provides an information display control apparatus, an information display control method, and a storage medium storing an information display control program, which are capable of displaying a plurality of filenames on a display unit so that the filenames are easily distinguished and original filenames are easily recognized. 
     Accordingly, a first aspect of the present invention provides an information display control apparatus that displays a plurality of filenames onto a display unit for allowing a user to select, comprising a first determination unit configured to determine whether the number of characters of each filename is larger than the predetermined number of characters, a second determination unit configured to compare the filenames to determine whether the filenames have a common part in which common characters continue more than the preset number of characters, and a display control unit configured to display a part of the filename as a partially displayed filename onto the display unit within the predetermined number of characters and to display the full filename onto the display unit by rolling characters when the first determination unit determines that the number of characters of the filename is larger than the predetermined number of characters. The display control unit changes character rolling speed according to a determination result by the second determination unit when the filename is displayed by rolling characters. 
     Accordingly, a second aspect of the present invention provides an information display control apparatus that displays a plurality of filenames onto a display unit for allowing a user to select, comprising a first determination unit configured to determine whether the number of characters of each filename is larger than the predetermined number of characters, a second determination unit configured to compare the filenames to determine whether the filenames have a common part in which common characters continue more than the preset number of characters, and a display control unit configured to replace at least a part of the common part with a predetermined symbol and to display the replaced filename onto the display unit when the first determination unit determines that the number of characters of the filename is larger than the predetermined number of characters and when the second determination unit determines that there is the common part. 
     Accordingly, a third aspect of the present invention provides an information display control method for displaying a plurality of filenames onto a display unit for allowing a user to select, comprising a first determination step of determining whether the number of characters of each filename is larger than the predetermined number of characters, a second determination step of comparing the filenames to determine whether the filenames have a common part in which common characters continue more than the preset number of characters, a first display control step of displaying a part of the filename as a partially displayed filename onto the display unit within the predetermined number of characters when it is determined that the number of characters of the filename is larger than the predetermined number of characters in the first determination step, and of displaying the full filename of a selected filename onto the display unit by rolling characters when the partially displayed filename is pointed as the selected filename, and a second display control step of changing character rolling speed according to the determination result in the second determination step when displaying the selected filename by rolling characters. 
     According to the present invention, since the character rolling speed is changed according to the determination result of whether the similar filenames have a common part, a user can not only distinguish the filenames easily, but also can recognize original filenames easily. As a result, the user can select an image file smoothly. 
     Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a functional block diagram schematically showing a configuration of a printer that is provided with an information display control apparatus according to an embodiment of the present invention. 
         FIG. 2  is a block diagram showing details of the information display control apparatus (a controller unit) of the printer shown in  FIG. 1 . 
         FIG. 3  is a block diagram showing details of an operation unit of the printer shown in  FIG. 1 . 
         FIG. 4  is a flowchart showing a first example of a file display process in the information display control apparatus shown in  FIG. 1 . 
         FIG. 5  is a view showing an example of a filename list displayed on the operation unit shown in  FIG. 1 . 
         FIG. 6A  is a view showing a screen displayed on the display unit (LCD) of the operation unit shown in  FIG. 3  as a result of executing the file display process shown in  FIG. 4  for the filename list shown in  FIG. 5 . 
         FIG. 6B  is a view showing a screen where the selected filename in the screen shown in  FIG. 6A  is displayed by rolling characters and a character rolling speed becomes slow. 
         FIG. 6C  is a view showing a screen where the selected filename in the screen shown in  FIG. 6A  is displayed by rolling characters and a character rolling speed becomes fast. 
         FIG. 7  is a flowchart showing a second example of the file display process in the information display control apparatus shown in  FIG. 1 . 
         FIG. 8A  is a view showing a screen displayed on the display unit (LCD) of the operation unit shown in  FIG. 3  as a result of executing the file display process shown in  FIG. 7  for the filename list shown in  FIG. 5 . 
         FIG. 8B  is a view showing a screen displaying a common part in the selected filename among the filenames in the screen shown in  FIG. 8A . 
         FIG. 8C  is a view showing a screen displaying a different part in the selected filename among the filenames in the screen shown in  FIG. 8A . 
         FIG. 9  is a flowchart showing a third example of the file display process in the information display control apparatus shown in  FIG. 1 . 
         FIG. 10  is a view showing another example of the filename list displayed on the operation unit shown in  FIG. 1 . 
         FIG. 11A  is a view showing a screen displayed on the LCD of the shown in  FIG. 3  as a result of executing the file display process shown in  FIG. 9  for the filename list shown in  FIG. 10 . 
         FIG. 11B  is a view showing a screen displaying a common part in the selected filename among the filenames in the screen shown in  FIG. 11A . 
         FIG. 11C  is a view showing a screen displaying a different part in the selected filename among the filenames in the screen shown in  FIG. 11A . 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Hereafter, embodiments according to the present invention will be described in detail with reference to the drawings. 
       FIG. 1  is a functional block diagram schematically showing a configuration of a printer that is provided with an information display control apparatus according to an embodiment of the present invention. 
     As shown in  FIG. 1 , the printer (an image forming apparatus)  1  is provided with a controller unit  102 , an operation unit  103 , and a printer unit  104  that have a function as the information display control apparatus. The controller unit  102  is connected with the operation unit  103  and the printer unit  104  so as to enable communication. The controller unit  102  controls the operation unit  103  and the printer unit  104 . For example, the operation unit  103  is equipped with various keys and a display unit. The controller unit  102  controls the printer unit  104  for printing according to key operations. The controller unit  102  displays a variety of information including status (condition) of the printer unit  104  onto the display unit. 
     It should be noted that the controller unit  102  first displays a filename given to an image file onto the display unit when displaying the image file recorded in a recording medium etc. to the screen. Then, when the image file to be displayed on the display unit is selected, the controller unit  102  displays the image file corresponding to the filename concerned on the display unit. 
     In the illustrated example, the controller unit  104  is connected with a host computer  101  via the network etc., and according to the image data sent from the host computer  101 , the controller unit  104  controls the printer unit  104 , and executes print. A USB memory  105 , which is one of the external recording media, is directly connected to the controller unit  102 . Then, the controller unit  102  controls the printer unit  104  according to the image data recorded on USB memory  105 , and executes print. 
     When printing, the controller unit  102  converts the image data obtained from the host computer  101  or the USB memory  105  into data that can be processed by the printer unit  104 , and transmits the converted data to the printer unit  104 . As mentioned above, the control section  102  controls the printer unit  104  according to operation of the operation unit  103 , and sends the status of the printer unit  104  to the operation unit  103 . 
       FIG. 2  is a block diagram showing details of the controller unit  102  shown in  FIG. 1 . 
     As shown in  FIG. 2 , the controller unit  102  has a CPU  201 , a ROM  202 , a RAM  203 , a host interface (IF) unit  204 , an operation unit IF section  205 , a printer IF section  206 , and a USB-IF section  207 . Then, the CPU  201 , the ROM  202 , the RAM  203 , the host IF section  204 , the operation unit IF section  205 , the printer IF section  206 , and USB-IF section  207  are mutually connected via an internal bus  208 . 
     The controller unit  102  is connected to the host computer  101  via the host IF section  204 , and is connected to the operation unit  103  via the operation unit IF section  205 . The controller unit  102  is connected to the printer unit  104  via the printer IF section  206 . It should be noted that the USB memory  105  is directly connected to the USB-IF section  207 . 
     The CPU  201  loads a program stored in the ROM  202  into the RAM  203 , executes it to control the entire controller unit  102 . The ROM  202  stores programs and an OS that are executed by the CPU  201 . The RAM  203  is not only used as a work memory to which a program is developed, but also is used as an image memory for an image data process. 
     The host IF section  204  may be configured so as to connect to the host computer  101  via a network such as the Ethernet (the registered trademark) etc., or may be configured so as to connect to the host computer  101  via a local connection by a USB interface etc. Then, the CPU  201  communicates with the host computer  101  via the host IF section  204  and exchanges job data (image data), a command, and status. 
     The operation unit IF section  205  is used to communicate with the operation unit  103 . The CPU  201  exchanges a command and status with the operation unit  103  via the operation unit IF section  205 . The CPU  201  sends display data to the operation unit  103 . The operation unit  103  displays information corresponding to the display data onto the display unit (for example, an LCD). 
     The printer IF section  206  is used to communicate with the printer unit  104 . The CPU  201  exchanges a command, status, and image data with the printer unit  104  via the printer IF section  206 . The USB-IF section  207  is used to communicate with the USB memory  105 . The CPU  201  exchanges image data, a command, and status with the USB memory  105  via the USB-IF section  207 . 
       FIG. 3  is a block diagram showing details of the operation unit  103  shown in  FIG. 1 . 
     As shown in  FIG. 3 , the operation unit  103  has a CPU  301 , a ROM  302 , a RAM  303 , a controller IF section  304 , an LCD (a liquid crystal display) driver  305 , a key matrix  307 , and various LED (light emitting diode) indicators  309 . The CPU  301 , the ROM  302 , the RAM  303 , the controller IF section  304 , the LCD driver  305 , the key matrix  307 , and the LED indicators  309  are mutually connected via an internal bus  310 . Then, an LCD  306  is connected to the LCD driver  305 . Various keys  308  of a keyboard, for example, are connected to the key matrix  307 . It should be noted that the operation unit  103  is connected to the controller unit  102  via the controller IF section  304 . 
     The CPU  301  loads a program stored in the ROM  302  into the RAM  303 , and executes it to control the entire operation unit  103 . The ROM  302  stores programs that are executed by the CPU  301 . The RAM  303  is used as a work memory to which a program is developed. 
     The controller IF section  304  is used to communicate with the controller unit  102 . The CPU  301  exchanges a command and status with the controller unit  102  via the controller IF section  304 . The CPU  301  receives display data displayed on the LCD  306  from the controller unit  102  via the controller IF  304 . 
     The CPU  301  controls the LCD driver  305  to drive the LCD  306 . Then, the CPU  301  displays the display data received from the controller unit  102  onto the LCD  306  via the controller IF section  304 . 
     The various keys  308  includes specific keys such as a cross key that moves a cursor vertically and horizontally, a numeric keypad, and an OK key. A user instructs the CPU  301  by operating the various keys. That is, when the various keys  308  are operated, instructions according to the key operations are notified to the CPU  301  via the key matrix  307 . 
     The LED indicators  309  notify a user of the status (an error, a sheet empty, a toner empty, etc.) of the apparatus. The CPU  301  controls on/off and blinking of the LED indicators  309  according to the instructions from the controller unit  102 . 
       FIG. 4  is a flowchart showing a first example of a file display process in the controller unit  102  (the information display control apparatus) shown in  FIG. 1 . 
     The first example of the file display process will be described with reference to  FIG. 1  through  FIG. 4 . When the USB memory  105  is connected (inserted) to the USB-IF section  207 , the CPU  201  checks a plurality of image files stored in the USB memory  105 , and starts a preparation for printing the image file concerned. 
     Here, the CPU  201  checks whether the number of characters of a filename of each image file is larger than the number of characters that can be displayed on the LCD  306 . That is, the CPU  201  checks whether there is a filename of which the number of characters is larger than the number of characters that can be displayed (the predetermined number of characters) in step S 401 . 
     When there is no filename of which the number of characters is larger than the number of characters that can be displayed (NO in the step S 401 ), the CPU  201  sends the filenames to the operation unit  103  via the operation unit IF section  205 . In the operation unit  103 , the CPU  301  controls the LCD driver  305  to display the filenames on the LCD  306 . That is, the CPU  301  displays a filename list on the LCD  306  as-is (step S 402 ). Then, when a user selects one of the listed filenames by a selection pointer, the CPU  301  highlights (inverts) the original filename onto the LCD  306  (step S 403 ). And the CPU  301  finishes the display process. 
     On the other hand, when there is a filename (this is called a long filename below) of which the number of characters is larger than the number of characters that can be displayed (YES in the step S 401 ), the CPU  201  compares the filenames to extract a common part in which common characters continue more than the preset number of characters (step S 404 ). Here, the preset number of characters is 1, for example. Next, the CPU  201  instructs the CPU  301  to display only a head part of a long filename within the number of characters that can be displayed onto the LCD  306  (step S 405 ). 
     Accordingly, the CPU  301  displays only the part of the long filename within the number of characters that can be displayed onto the LCD  306 . That is, when the number of characters of the filename is larger than the predetermined number (the number of characters that can be displayed), a part of a filename will be displayed as a partially displayed filename within the number of characters that can be displayed. It should be noted that the CPU  301  displays a filename (it is called a regular-length filename below) other than a long filename onto the LCD  306  as-is. 
     In this case, when the selection pointer points to a long filename, the CPU  301  highlights the long filename by rolling characters. That is, when the partially displayed filename is pointed as a selected filename, the full filename of the selected filename concerned is highlighted by rolling characters in the top-to-tail direction. On the other hand, when the selection pointer points to a regular-length filename, the CPU  301  highlights the regular-length filename as-is without rolling characters. That is, the CPU  301  displays a long filename and a regular-length filename in different ways, respectively, when the selection pointer points to a filename. 
     Next, the CPU  201  determines whether long filenames have a common part (step S 406 ). When determining that the long filenames have the common part (YES in the step S 406 ), the CPU  201  instructs the CPU  301  to accelerate a character rolling speed when displaying the common part in the long filename to which the selection pointer points. 
     Accordingly, when displaying the common part in the long filename pointed by the selection pointer onto the LCD  306 , the CPU  301  accelerates the character rolling speed (step S 407 ). That is, when the long filename has a common part, the character rolling speed is changed. 
     As a result, when similar filenames are displayed onto the LCD  306 , a different part (difference) is emphasized. That is, the user can check the common part in the filename quickly and can check the different part slowly, which allows to select a file smoothly. 
     On the other hand, when determining that the long filenames do not have the common part (NO in the step S 406 ), the CPU  201  instructs the CPU  301  to keep the character rolling speed constant when displaying the long filename to which the selection pointer points. 
     Accordingly, the CPU  301  displays the long filename to which the selection pointer points onto the LCD  306  at the constant character rolling speed (step S 408 ). That is, when there is no common part, a long filename is displayed at the constant character rolling speed. 
     As mentioned above, since a long filename is displayed by rolling characters, a user can check the long filename certainly even if the LCD  306  with a character number limit is used. 
       FIG. 5  is a view showing an example of a filename list displayed on the operation unit  103  shown in  FIG. 1 .  FIG. 6A  is a view showing a screen displayed on the LCD  306  shown in  FIG. 3  as a result of executing the file display process shown in  FIG. 4  for the filename list shown in  FIG. 5 .  FIG. 6B  is a view showing a screen where the selected filename in the screen shown in  FIG. 6A  is displayed by rolling characters and the character rolling speed becomes slow.  FIG. 6C  is a view showing a screen where the selected filename in the screen shown in  FIG. 6A  is displayed by rolling characters and the character rolling speed becomes fast. 
     The USB memory  105  shall store the filename list shown in  FIG. 5 . In this filename list, all the filenames are long filenames. Therefore, according to the flowchart in  FIG. 4 , parts of filenames within the number of characters that can be displayed onto the LCD  306  are displayed onto the LCD  306  (see  FIG. 6A ). 
     In  FIG. 6A , when the selection pointer points to the filename F 1 , the filename F 1  concerned is displayed by rolling characters in the head-to-tail direction as shown by the solid line arrow. When characters of the filename F 1  that are other than the common part with the filenames F 2  through F 5  are displayed by rolling the characters, the character rolling speed becomes slower than regular. In the screen shown in  FIG. 6B , since the part of the filename F 1  that is other than the common part is displayed, the character rolling speed becomes slow (first character rolling speed). 
     On the other hand, in the screen shown in  FIG. 6C , since the characters of the filename F 1  that are common to the filenames F 2  through F 5  are displayed, the character rolling speed becomes fast. That is, the character rolling speed becomes second character rolling speed that is faster than the first character rolling speed. 
     In the illustrated example, the filename to which the selection pointer points is displayed by rolling the characters of the filename in the top-to-tail direction. The full filename is displayed repeatedly. When the numerals at the tail of the filename that are different from the similar filenames are displayed, the character rolling speed becomes slow. On the other hand, when the characters that are common to the similar filenames are displayed, the character rolling speed becomes fast. 
       FIG. 7  is a flowchart showing a second example of the file display process in the information display control apparatus shown in  FIG. 1 . 
     The second example of the file display process will be described with reference to  FIG. 1  through  FIG. 3  and  FIG. 7 . When the USB memory  105  is connected (inserted) to the USB-IF section  207 , the CPU  201  checks image files stored in the USB memory  105  in order to determine whether there is a filename of which the number of characters is larger than the number of characters that can be displayed onto the LCD  306  (step S 501 ). 
     When there is no filename of which the number of characters is larger than the number of characters that can be displayed (NO in the step S 501 ), the CPU  201  sends the filenames to the operation unit  103  via the operation unit IF section  205 . That is, the CPU  301  displays a filename list on the LCD  306  as-is (step S 502 ). Then, when a user selects one of the listed filenames by the selection pointer, the CPU  301  highlights (inverts) the original filename onto the LCD  306  (step S 403 ). Then, the CPU  301  finishes the display process. 
     On the other hand, when there is a filename of which the number of characters is larger than the number of characters that can be displayed (YES in the step S 501 ), the CPU  201  compares the filenames to extract a common part in which common characters continue more than the preset number of characters (step S 504 ). 
     Next, the CPU  201  determines whether long filenames have a common part (step S 505 ). When there is no common part (NO in the step S 505 ), the CPU  201  instructs the CPU  301  to display a head part of the long filename within the number of characters that can be displayed onto the LCD  306  (step S 506 ). 
     Accordingly, the CPU  301  displays only the head part of the long filename within the number of characters that can be displayed onto the LCD  306 . It should be noted that the CPU  301  displays a regular-length filename onto the LCD  306  as-is. 
     In this case, when the selection pointer points to a long filename, the CPU  301  highlights the long filename by rolling characters. Here, the CPU  301  displays a long filename by rolling characters in the top-to-tail direction (step S 507 ). On the other hand, when the selection pointer points to a regular-length filename, the CPU  301  highlights the regular-length filename as-is without rolling characters. 
     When the long filename has a common part (YES in the step S 505 ), the CPU  201  determines whether the common part is included in a first half of the long filename (step S 508 ). When the common part is not included in the first half (NO in the step S 508 ), the CPU  101  proceeds with the process to the step S 506  and continues the process. 
     On the other hand, when the common part is included in the first half of the long filename (YES in the step S 508 ), the CPU  201  instructs the CPU  301  to display a tail part of the long filename within the number of characters that can be displayed onto the LCD  306  (step S 509 ). 
     Accordingly, the CPU  301  displays only the tail part of the long filename within the number of characters that can be displayed onto the LCD  306 . It should be noted that the CPU  301  displays a regular-length filename onto the LCD  306  as-is as described above. 
     In this case, when the selection pointer points to a long filename, the CPU  301  highlights the long filename by rolling characters. Here, the CPU  301  displays the long filename by rolling characters in the tail-to-top direction (step S 510 ). On the other hand, when the selection pointer points to a regular-length filename, the CPU  301  highlights the regular-length filename as-is without rolling characters. 
     Thus, when there are similar filenames, the user can check a different part (difference) on the first screen. Then, when the selection pointer points to the filename concerned, the filename is displayed by rolling characters and the user can check the full filename. As a result, the user can check the long filename certainly even if the LCD  306  with a character number limit is used. 
     It should be noted that the CPU  301  may decrease the character rolling speed when displaying the different characters in the same manner as the example shown in  FIG. 4 . 
       FIG. 8A  is a view showing a screen displayed on the LCD  306  shown in  FIG. 3  as a result of executing the file display process shown in  FIG. 7  for the filename list shown in  FIG. 5 .  FIG. 8B  is a view showing a screen displaying a common part in the selected filename among the filenames in the screen shown in  FIG. 8A .  FIG. 8C  is a view showing a screen displaying a different part in the selected filename among the filenames in the screen shown in  FIG. 8A . 
     According to the flowchart in  FIG. 7 , parts of filenames within the number of characters that can be displayed onto the LCD  306  are displayed onto the LCD  306  (see  FIG. 8A ). In the example in  FIG. 5 , since the common part in the filenames is included in the first half, the tail parts of the filenames are displayed. In  FIG. 8A , when the selection pointer points to the filename F 1 , the filename F 1  concerned is displayed by rolling characters in the direction as shown by the solid line arrow. In this case, since each of the filenames F 1  through F 5  has the different part in the second half of a filename, the filename is displayed by rolling characters in the tail-to-top direction. 
     In the illustrated example, when the characters of the filename F 1  that are different from the filenames F 2  through F 5  are displayed by rolling the characters, the character rolling speed becomes slower than regular. Since the common part in the filename F 1  is displayed in the screen shown in  FIG. 8B , the character rolling speed becomes fast. 
     On the other hand, in the screen shown in  FIG. 8C , since the characters of the filename F 1  that are different from the filenames F 2  through F 5  are displayed, the character rolling speed becomes slow. 
     In the illustrated example, the filename F 1  to which the selection pointer points is displayed by rolling the characters of the filename in the tail-to-top direction. The full filename is displayed repeatedly. When the numerals at the tail of filename that are different from the similar filenames are displayed, the character rolling speed becomes slow. On the other hand, when the characters that are common to the similar filenames are displayed, the character rolling speed becomes fast. 
       FIG. 9  is a flowchart showing a third example of the file display process in the information display control apparatus shown in  FIG. 1 . 
     The third example of the file display process will be described with reference to  FIG. 1  through  FIG. 3  and  FIG. 9 . When the USB memory  105  is connected to the USB-IF section  207 , the CPU  201  checks image files stored in the USB memory  105  in order to determine whether there is a filename given to each of the image file of which the number of characters is larger than the number of characters that can be displayed (step S 601 ). 
     When there is no filename of which the number of characters is larger than the number of characters that can be displayed (NO in the step S 601 ), the CPU  201  sends the filenames to the operation unit  103  via the operation unit IF section  205 . In the operation unit  103 , the CPU  301  displays the filenames on the LCD  306  as-is (step S 602 ). Then, when a user selects one of the listed filenames by the selection pointer, the CPU  301  highlights (inverts) the original filename onto the LCD  306  (step S 603 ). Then, the CPU  301  finishes the display process. 
     On the other hand, when there is a filename of which the number of characters is larger than the number of characters that can be displayed (YES in the step S 601 ), the CPU  201  compares the filenames to extract a common part in which common characters continue more than the preset number of characters (step S 604 ). 
     Next, the CPU  201  determines whether long filenames have a common part (step S 605 ). When there is no common part (NO in the step S 605 ), the CPU  201  instructs the CPU  301  to display a head part of the long filename within the number of characters that can be displayed onto the LCD  306  (step S 606 ). 
     Accordingly, the CPU  301  displays only the head part of the long filename within the number of characters that can be displayed onto the LCD  306 . It should be noted that the CPU  301  displays a regular-length filename onto the LCD  306  as-is. 
     In this case, when the selection pointer points to a long filename, the CPU  301  displays the long filename by rolling characters onto the screen. When displaying a filename by rolling characters, the CPU  301  displays the long filename by rolling characters in the top-to-tail direction (step S 607 ). 
     When the long filename has a common part (YES in the step S 605 ), the CPU  201  replaces at least a part of the common part with a predetermined symbol (for example, “ . . . ”), and sends the replaced filename and the original filename to the operation unit  103 . Then, the CPU  301  displays the replaced filename onto the LCD  306  (step S 608 ). In this case, the number of characters of the replaced filename is equal to or smaller than the number of characters that can be displayed. 
     When the selection pointer points to the replaced filename, the CPU  301  restores the replaced filename to the original filename, and displays the original filename onto the LCD  306  by rolling characters (step S 609 ). In this case, the CPU  301  displays a long filename by rolling characters in the top-to-tail direction, for example. 
     The replaced filenames are displayed onto the LCD  306  with a character number limit. And when the selection pointer points to the replaced filename, the original filename is displayed by rolling the characters. Accordingly, when a user selects the filename while checking a different part, the user can check the full filename. 
     It should be noted that the CPU  301  may decrease the character rolling speed when displaying the different part. 
       FIG. 10  is a view showing another example of the filename list displayed on the operation unit  103  shown in  FIG. 1 .  FIG. 11A  is a view showing a screen displayed on the LCD  306  shown in  FIG. 3  as a result of executing the file display process shown in  FIG. 9  for the filename list shown in  FIG. 10 .  FIG. 11B  is a view showing a screen displaying a common part in the selected filename among the filenames in the screen shown in  FIG. 11A .  FIG. 11C  is a view showing a screen displaying a different part in the selected filename among the filenames in the screen shown in  FIG. 11A . 
     The USB memory  105  shall store the filename list shown in  FIG. 10 . In this filename list, all the filenames are long filenames that have a common part. Therefore, according to the flowchart in  FIG. 9 , replaced filenames are displayed onto the LCD  306  (see  FIG. 11A ). That is, the common part is replaced with the symbol “ . . . ”, and is displayed. 
     In  FIG. 11A , when the selection pointer points to the replaced filename F 1 , the CPU  301  restores the filename concerned to the original filename, and display by rolling characters (see  FIG. 11B ). In this case, the original filename F 1  is displayed by rolling the characters in the top-to-tail direction as shown by the solid line arrow. 
     In the illustrated example, when the characters of the filename F 1  that are common to the filenames F 2  through F 5  are displayed by rolling the characters, the character rolling speed becomes fast. Since the common part in the filename F 1  is displayed in the screen shown in  FIG. 11B , the character rolling speed becomes fast. 
     On the other hand, in the screen shown in  FIG. 11C , since the characters of the filename F 1  that are different from the filenames F 2  through F 5  are displayed, the character rolling speed becomes slow. 
     In the illustrated example, the full original filename F 1  to which the selection pointer points is displayed repeatedly. When the numerals at the tail of filename that are different from the similar filenames are displayed, the character rolling speed becomes slow. On the other hand, when the characters that are common to the similar filenames are displayed, the character rolling speed becomes fast. 
     In the example shown in  FIG. 10 , the upper three filenames are mutually similar, and the lower two filenames are mutually similar. In the third example, since at least a part of the common part of the filenames shown in  FIG. 10  is replaced with the symbol “ . . . ” to form the replaced filenames, the different parts among the similar filenames are emphasized. 
     In the example shown in  FIG. 10 , the upper three filenames have the different parts at their tails. The lower two filenames have the different parts around their centers. 
     Therefore, in the illustrated example, the middle parts of the upper three filenames are replaced with the symbol “ . . . ”, and the middle and tail parts of the lower two filenames except the different parts are replaced with the symbol “ . . . ”. 
     Then, as mentioned above, since the selection pointer points to the replaced filename F 1 , the CPU  301  restores the filename concerned to the original filename, and display by rolling the characters in the top-to-tail direction. 
     The full filename is displayed repeatedly. When the numerals at the tail of the filename that are different from the similar filenames are displayed, the character rolling speed becomes slow. When the different part is included in the first half of the filename, the direction for rolling characters may be changed to the tail-to-top direction. 
     Although the embodiments of the invention have been described, the present invention is not limited to the above-mentioned embodiment, the present invention includes various modifications as long as the concept of the invention is not deviated. 
     For example, an information display control method that corresponds to the function of the above-mentioned embodiment may be performed by the information display control apparatus. Moreover, a computer with which the information display control apparatus is provided may execute an information display control program that has the functions of the above-mentioned embodiment. In these cases, each of the information display control method and the information display control program includes at least a first determination step, a second determination step, a first display control step, and a second display control step. 
     Other Embodiments 
     Aspects of the present invention can also be realized by a computer of a system or apparatus (or devices such as a CPU or MPU) that reads out and executes a program recorded on a memory device to perform the functions of the above-described embodiment(s), and by a method, the steps of which are performed by a computer of a system or apparatus by, for example, reading out and executing a program recorded on a memory device to perform the functions of the above-described embodiment(s). For this purpose, the program is provided to the computer for example via a network or from a recording medium of various types serving as the memory device (e.g., computer-readable medium). 
     While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions. 
     This application claims the benefit of Japanese Patent Application No. 2010-173627, filed on Aug. 2, 2010, which is hereby incorporated by reference herein in its entirety.