Abstract:
A information display apparatus includes a content storage module, a controller, a specification module, and a marker information storage module. The controller controls a text to be displayed. The specification module specifies, based on a user&#39;s operation, a character string, as a marker display character string in the displayed text. The marker information storage module stores position information of the marker display character string within a storage region of the content storage module, and stores a stored time where the position information is stored as being related to the position information. The controller allows the text in an identifiable manner based on the position information, wherein a mode of the identifiable display is differed in accordance with time elapsed since the stored time for the marker display character string.

Description:
CROSS REFERENCE TO RELATED APPLICATION(S) 
       [0001]    The present disclosure relates to the subject matters contained in Japanese Patent Application No. 2010-166666 filed on Jul. 26, 2010, which are incorporated herein by reference in its entirety. 
       FIELD 
       [0002]    The present invention relates to an information display apparatus and a computer-readable storage medium. 
       BACKGROUND 
       [0003]    An information display apparatus in which a text content and a dictionary database are incorporated is equipped with a marker function in order to improve learning effects. As used herein, the term “marker function” refers to a function for storing, when an operation for registering a character string in a text as a marker display character string is received from a user, position information of the character string, and for displaying the character string with a marker to accentuate the character string when the same text is displayed later (see JP-A-2002-7420 and JP-A-2004-213299, for instance). 
         [0004]    Further, for an information display apparatus equipped with such a marker function, a technique for displaying a marker display character string in a hidden manner has recently been proposed (see JP-A-2006-293186, for instance). With this technique, a character string portion displayed in a hidden manner can be used for rote learning, thus enabling further improvement in learning effects. 
         [0005]    Actually, when a large number of marker display character strings exist in a text, display thereof is complicated, and it is difficult to know the importance of each marker display character string. This may reduce learning effects. Therefore, when a plurality of marker display character strings exist in a text, registration as the marker display character string is preferably cancelled for the character string whose importance reduced. 
         [0006]    However, in the technique, when a plurality of marker display character strings exist in a text, a user is forced to determine which marker display character string should be subjected to registration cancellation by himself or herself, thus requiring much time and effort. 
       SUMMARY OF THE INVENTION 
       [0007]    It is one of objects of the present invention to provide an information display apparatus and a computer-readable storage medium which enable easy canceling of registration of a marker display character string. 
         [0008]    According to a first aspect of the invention, there is provided an information display apparatus including: a display device; a content storage module that stores a content including one or more pieces of item information, each piece of item information including an item and a text associated with the item; a text display controller that controls, based on a user&#39;s operation, the display device to display a certain text associated with a certain item in the content stored in the content storage module; a character string specification module that specifies, based on a user&#39;s operation, a character string, as a marker display character string, included in the certain text displayed on the display device; a marker information storage module that stores position information of the marker display character string within a storage region of the content storage module, and stores a stored time where the position information is stored as being related to the position information; and a marker display controller that controls the display device to display the certain text including the marker display character string in an identifiable manner based on the position information of the marker display character string stored in the marker information storage module, wherein, by the marker display controller, a mode of the identifiable display of the marker display character string is differed in accordance with time elapsed since the stored time for the marker display character string. 
         [0009]    According to a second aspect of the invention, in the information display apparatus according to the first aspect, the marker display controller may include a hidden-display controller that controls the display device to display the marker display character string as a latent image, when the time elapsed since the stored time for the marker display character string is equal to or greater than a given period of time. 
         [0010]    According to a third aspect of the invention, the information display apparatus according to the second aspect may include: a hidden character string specification module that specifies, as a specified marker display character string, one of a plurality of marker display character strings each displayed as a latent image by the hidden-display controller based on a user&#39;s operation; a character string input module that receives an input operation for a character string from the user when the specified marker display character string is specified by the hidden character string specification module; a determination module that determines whether or not the specified marker display character string and the inputted character string inputted via the character string input module are substantially identical; a marker information automatic erasure module that erases, from the marker information storage module, information concerning the specified marker display character string when it is determined by the determination module that the specified marker display character string and the inputted character string are substantially identical; and a stored time resetting module that updates, with the time at the present moment, a stored time for the specified marker display character string in the marker information storage module when it is determined by the determination module that the specified marker display character string and the inputted character string are not substantially identical. 
         [0011]    According to a fourth aspect of the invention, in the information display apparatus according to any one of the first to the third aspect, the marker display controller may control the display device to display the marker display character string in an identifiable manner of a different mode in accordance with comparison results between the time elapsed since the stored time for the marker display character string and a plurality of given periods of time set in advance. 
         [0012]    According to a fifth aspect of the invention, there is provided a computer-readable storage medium that stores an information display program for causing a computer including a display device and a storage module to execute procedures including: storing, in the storage module, a content including one or more pieces of item information, each piece of item information including an item and a text associated with the item; controlling, based on a user&#39;s operation, the display device to display a certain text associated with a certain item in the content stored in the storage module; specifying, based on a user&#39;s operation, a character string, as a marker display character string, included in the certain text displayed on the display device; storing position information of the marker display character string within a storage region of the storage module, and storing a stored time where the position information is stored as being related to the position information; and controlling the display device to display the certain text including the marker display character string in an identifiable manner based on the position information of the marker display character string stored in the storage module, wherein a mode of the identifiable display of the marker display character string is differed in accordance with time elapsed since the stored time for the marker display character string. 
         [0013]    According to the present invention, when a character string in a displayed text is specified as a marker display character string based on a user&#39;s operation, position information of the marker display character string is stored, and a stored time of the position information is stored so as to be associated with the position information. In addition, when the text including the marker display character string is displayed, the marker display character string is displayed with a marker based on the position information of the stored marker display character string, and a mode of marker display for each marker display character string is changed in accordance with the time elapsed since the stored time for the marker display character string, thus making it possible to easily determine the marker display character string that has been registered for a long period of time. Accordingly, even when a plurality of marker display character strings exist in a text, it is possible to easily determine which marker display character string should be subjected to registration cancellation, and therefore, it is possible to easily cancel the registration of the marker display character string. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0014]    A general configuration that implements the various features of the invention will be described with reference to the drawings. The drawings and the associated descriptions are provided to illustrate embodiments of the invention and should not limit the scope of the invention. 
           [0015]      FIG. 1  is a plan view schematically illustrating an electronic dictionary. 
           [0016]      FIG. 2  is a block diagram illustrating an internal configuration of the electronic dictionary. 
           [0017]      FIG. 3A  is a diagram illustrating a data structure of a dictionary database. 
           [0018]      FIG. 3B  is a diagram illustrating a data structure of a set time table. 
           [0019]      FIG. 4  is a diagram illustrating a data structure of a marker information database. 
           [0020]      FIG. 5  is a flow chart illustrating information display processing. 
           [0021]      FIG. 6  is a flow chart illustrating a marker time coupled display processing. 
           [0022]      FIG. 7  is a flow chart illustrating a test mode processing. 
           [0023]      FIG. 8  is a flow chart illustrating a marker mode processing. 
           [0024]      FIGS. 9A to 9C  are diagrams illustrating information displayed on a display device. 
           [0025]      FIGS. 10A to 100  are diagrams illustrating information displayed on the display device. 
           [0026]      FIGS. 11A to 11C  are diagrams illustrating information displayed on the display device. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0027]    Hereinafter, an embodiment of the present invention in which an information display apparatus according to the present invention is applied to an electronic dictionary will be described in detail with reference to the drawings. 
       External Configuration 
       [0028]      FIG. 1  is a plan view of an electronic dictionary  1 . 
         [0029]    As illustrated in  FIG. 1 , the electronic dictionary  1  includes a main display  10 , a sub-display  11 , and a key group  2 . 
         [0030]    The main display  10  and the sub-display  11  displays various pieces of data such as characters and codes in response to an operation performed on the key group  2  by a user, and are each formed by a Liquid Crystal Display (LCD), an Electroluminescent Display (ELD) or the like. Note that the main display  10  and the sub-display  11  according to the present embodiment are formed integrally with a so-called touch panel  110  (see  FIG. 2 ), thus making it possible to receive an operation such as a handwriting input. 
         [0031]    The key group  2  includes various keys for receiving, from the user, operations for operating the electronic dictionary  1 . Specifically, the key group  2  includes a translate/select key  2   b,  character keys  2   c,  dictionary selection keys  2   d,  cursor keys  2   e,  a shift key  2   f,  a back key  2   g,  and a menu key  2   h.    
         [0032]    The translate/select key  2   b  is a key used, for example, to conduct a search and decide a headword. The character keys  2   c  are keys used, for example, for input of characters by the user, and include “A” to “Z” keys in the present embodiment. The dictionary selection keys  2   d  are keys used to select dictionary databases  90  . . . (see  FIG. 2 ) which will be described later. 
         [0033]    The cursor keys  2   e  are keys used, for example, to move a highlight position within a screen, i.e., a cursor position, and allow specification of upward, downward, rightward and leftward directions in the present embodiment. The shift key  2   f  is a key used, for example, to set a Japanese word as a search object. The back key  2   g  is a key used, for example, to back the current screen to the previously displayed screen. The menu key  2   h  is a key for making various mode settings. 
       Internal Configuration 
       [0034]    Next, an internal configuration of the electronic dictionary  1  will be described.  FIG. 2  is a block diagram illustrating the internal configuration of the electronic dictionary  1 . 
         [0035]    As illustrated in  FIG. 2 , the electronic dictionary  1  includes: a display device  40 ; an input module  30 ; a recording medium reader  50 ; a Central Processing Unit (CPU)  20 ; a flash Read Only Memory (ROM)  80 ; and a Random Access Memory (RAM)  70 . The respective modules of the electronic dictionary  1  are connected to each other so that mutual data communication is enabled via a bus  100 . 
         [0036]    The display device  40  includes the foregoing main display  10  and sub-display  11  so that various pieces of information are displayed on the main display  10  and the sub-display  11  based on display signals received from the CPU  20 . 
         [0037]    The input module  30  includes the foregoing key group  2  and touch panel  110  so that a signal corresponding to the pressed key or position of the touch panel  110  is outputted to the CPU  20 . 
         [0038]    The recording medium reader  50  reads information from a recording medium  50 A such as an SD card, USB memory or CD removably inserted. 
         [0039]    The CPU  20  carries out processing based on a given program in response to an inputted instruction, and performs, for example, transfer of an instruction or data to each functional module so as to carry out overall control of the electronic dictionary  1 . Specifically, in response to an operation signal or the like received from the input module  30 , the CPU  20  reads various programs stored in the flash ROM  80 , and carries out processing in accordance with the read programs. Then, the CPU  20  stores a processing result in the RAM  70 , and controls the display device  40  to output the processing result as appropriate. 
         [0040]    The flash ROM  80  is a memory that stores programs and data for implementing various functions of the electronic dictionary  1 . In the present embodiment, the programs and data stored in the flash ROM  80  include: an information display program  81 , according to the present invention; a content group  9 ; a marker information database  85 ; and a set time table  86 . 
         [0041]    The information display program  81  is a program for allowing the CPU  20  to carry out information display processing (see  FIGS. 5 to 8 ) which will be described later. 
         [0042]    The content group  9  has a plurality of contents including one or more pieces of item information in which a text is associated with each item. In the present embodiment, the content group  9  has a plurality of dictionary databases  90  and a plurality of text contents  91 . 
         [0043]    As illustrated in one example in  FIG. 3A , for example, the dictionary databases  90 , . . . each stores one or more pieces of headword information in which a headword serving as an item is associated with a text of explanatory information for the headword. Note that as the foregoing dictionary databases  90 , the dictionary databases  90  such as “JUNIOR HIGH SCHOOL SOCIAL STUDIES GLOSSARY”, “JAPANESE HISTORY SMALL ENCYCLOPEDIA” and “L ENGLISH-ENGLISH DICTIONARY” are included in the content group  9  in the present embodiment. 
         [0044]    The text contents  91  store a plurality of pieces of item information in which a plurality of types of items (such as chapter numbers) are each associated with a text. 
         [0045]    As illustrated in  FIG. 4 , the marker information database  85  stores: position information (hereinafter referred to as “marker display character string position information”) in the content group  9  for a character string (hereinafter referred to as a “marker display character string”) specified as a marker display object in the information display processing (see  FIGS. 5 to 8 ) described later; a time (hereinafter referred to as a “stored time”) at which the position information is stored in the marker information database  85 ; and a marker color for marker display of the marker display character string. The marker display character string position information, the stored time and the marker color are stored in the marker information database  85  so as to be associated with each other. More specifically, in the present embodiment, the marker information database  85  stores, as the marker display character string position information, an item name of a text in which the marker display character string is specified, the type of this item (such as a headword in the dictionary database  90  or a chapter number in the text content  91 ), a name of the content in which the text is included, and start and end positions of the marker display character string in the text. Further, the marker information database  85  stores year, month, day, hour, minute and second as the stored time in the present embodiment, but may store only year, month and day as the stored time. 
         [0046]    For time elapsed since the stored time stored in the marker information database  85 , the set time table  86  stores a plurality of types of set times serving as processing threshold values in the information display processing described later. More specifically, as illustrated in  FIG. 3B , the set time table  86  stores “30 DAYS” as a set time “ 1 ” and stores “180 DAYS” as a set time “ 2 ” in the present embodiment. Note that these set times are preferably set based on memory holding times for short term memory, intermediate term memory and long term memory. 
         [0047]    The RAM  70  includes a memory area for temporarily holding various programs executed by the CPU  20 , data concerning the execution of the programs, etc. 
       Operations 
       [0048]    Next, operations of the electronic dictionary  1  will be described with reference to  FIGS. 5 to 8 . 
       Information Display Processing 
       [0049]      FIGS. 5 to 8  are flow charts illustrating a flow of information display processing executed by reading the information display program  81  by the CPU  20 . 
         [0050]    In the information display processing, as illustrated in  FIG. 5 , the CPU  20  first determines whether or not a display instruction operation, by which one of items in one of contents in the content group  9  is selected as a display object, is performed by a user via the menu key  2   h  or the like (Step S 1 ). Upon determination that no display instruction operation is performed (NO in Step S 1 ) transition is made to another processing. 
         [0051]    On the other hand, when it is determined in Step S 1  that the display instruction operation is performed by the user (YES in Step S 1 ), the CPU  20  controls the main display  10  to display a text of the item of the display object (which will hereinafter be referred to as a “display object text”) in a full-screen manner (Step S 2 ). Furthermore, in this step, the CPU  20  controls the main display  10  to display a marker icon  101  and a time lapse icon  102  (see  FIG. 9A ) on an end portion of the main display  10 . 
         [0052]    In this case, the marker icon  101  receives an operation for starting a marker mode processing (Step S 9 ) described later. 
         [0053]    Moreover, the time lapse icon  102  receives a switching operation to determine whether or not processing should be performed in consideration of the time elapsed since the stored time stored in the marker information database  85 . In addition, the time lapse icon  102  is changed to an ON state when processing is performed in consideration of the elapsed time, and is changed to an OFF state when processing is performed without consideration of the elapsed time. 
         [0054]    Subsequently, the CPU  20  determines whether or not the time lapse icon  102  is in the ON state (Step S 3 ). Upon determination that the time lapse icon  102  is not in the ON state (NO in Step S 3 ), the CPU  20  detects, from the marker information database  85 , position information of a marker display character string included in the display object text, and allows the marker display character string indicated by the detected position information to be displayed with a marker in the text using a marker color associated with the position information (Step S 4 ). Then, the processing goes to Step S 8  described later. 
         [0055]    On the other hand, when it is determined in Step S 3  that the time lapse icon  102  is in the ON state (YES in Step S 3 ), the CPU  20  performs a marker time coupled display processing (Step S 5 ). 
         [0056]    Specifically, as illustrated in  FIG. 6 , in the marker time coupled display processing, the CPU  20  first detects, from the marker information database  85 , position information of marker display character strings included in the display object text, and determines whether or not a marker display character string, for which no processing has been performed yet in Steps T 2  to T 10  described later, exists in a marker display character string group associated with the detected position information (Step T 1 ). 
         [0057]    When it is determined in Step T 1  that one or more unprocessed marker display character strings exist (YES in Step T 1 ), the CPU  20  selects, as a processing object, the unprocessed marker display character string or one of the unprocessed marker display character strings (Step T 2 ). 
         [0058]    Then, the CPU  20  obtains, from the marker information database  85 , an information registration time “A” (year, month, day, hour, minute and second) for the marker display character string serving as a processing object (Step T 3 ), obtains a current time “B” (Step T 4 ), and calculates a difference “C” (=B−A) between the times “A” and “B” (Step T 5 ). 
         [0059]    Subsequently, the CPU  20  makes a comparison between the set time “ 1 ” (30 days in this embodiment) set in advance in the set time table  86  and the difference “C”, thereby determining whether or not the difference “C” is smaller than the set time “ 1 ” (Step T 6 ). 
         [0060]    When it is determined in Step T 6  that the difference “C” is smaller than the set time “ 1 ” (YES in Step T 6 ), the CPU  20  sets the marker display character string, which is to be selected, to a display mode “1” (Step T 7 ), and then the processing goes to Step T 1  described above. In this case, as the display mode “1”, a mode in which a marker color has a given reference density is used. 
         [0061]    On the other hand, when it is determined in Step T 6  that the difference “C” is equal to or greater than the set time “ 1 ” (NO in Step T 6 ), the CPU  20  makes a comparison between the set time “ 2 ” (180 days in this embodiment) set in advance in the set time table  86  and the difference “C”, thereby determining whether or not the difference “C” is smaller than the set time “ 2 ” (Step T 8 ). 
         [0062]    When it is determined in Step T 8  that the difference “C” is smaller than the set time “ 2 ” (YES in Step T 8 ), the CPU  20  sets the marker display character string, which is to be selected, to a display mode “2” (Step T 9 ), and then the processing goes to Step T 1  described above. In this case, as the display mode “2”, a mode in which a marker color has a density lower than the reference density is used. 
         [0063]    On the other hand, when it is determined in Step T 8  that the difference “C” is equal to or greater than the set time “ 2 ” (NO in Step T 8 ), the CPU  20  sets the marker display character string, which is to be selected, to a display mode “3” (Step T 10 ), and then the processing goes to Step T 1  described above. In this case, as the display mode “3”, a mode in which a marker color density is increased so that the marker display character string becomes a latent image (so that visual recognition thereof is difficult) is used. 
         [0064]    Then, when it is determined in Step T 1  that no unprocessed marker display character string exists (NO in Step T 1 ), the CPU  20  allows each marker display character string in the display object text to be displayed with a marker in the mode set in Step T 7 , T 9  or T 10  described above (Step T 20 ), and ends the marker time coupled display processing. With the above-described marker time coupled display processing, each marker display character string will be displayed with a marker in the mode that is changed in accordance with the time elapsed since the stored time of the position information. Note that when not a single marker display character string exists in the text in Step T 20 , the CPU  20  ends the marker time coupled display processing without performing any processing. 
         [0065]    Upon end of the above-described marker time coupled display processing, as illustrated in  FIG. 5 , the CPU  20  subsequently determines whether or not a touch operation is performed on one of the marker display character strings, which is displayed in a hidden manner as a latent image (Step S 6 ). Upon determination that no touch operation is performed (NO in Step S 6 ), the processing goes to Step S 8  described later. 
         [0066]    On the other hand, when it is determined in Step S 6  that a touch operation is performed on the marker display character string displayed in a hidden manner (YES in Step S 6 ), the CPU  20  performs a test mode processing for the marker display character string specified by the touch operation, which will hereinafter be referred to as a “specified marker display character string” (Step S 7 ). 
         [0067]    Specifically, as illustrated in  FIG. 7 , in the test mode processing, the CPU  20  first receives, via the sub-display  11 , a handwriting input for the specified marker display character string (Step U 1 ). However, in Step U 1 , a character string may be received via the key group  2 . 
         [0068]    Subsequently, the CPU  20  performs character recognition of a handwritten character string, and then makes a comparison between the handwritten character string and the specified marker display character string, thus determining whether or not both of the character strings are substantially identical, i.e., whether or not the handwritten character string is correct (Step U 2 ). 
         [0069]    Then, when it is determined in Step U 2  that the handwritten character string is correct (CORRECT in Step U 2 ), the CPU  20  controls the main display  10  to display a message indicative of this fact. Thereafter, the CPU  20  erases registration information of the specified marker display character string from the marker information database  85 , and cancels marker display of the specified marker display character string (Step U 3 ), thus ending the test mode processing. 
         [0070]    On the other hand, when it is determined in Step U 2  that the handwritten character string is incorrect (INCORRECT in Step U 2 ), the CPU  20  allows a message indicative of this fact to be displayed, updates the stored time for the specified marker display character string in the marker information database  85  with the time at the present moment (at the determination moment) (Step U 4 ), and then ends the test mode processing. Note that in Step U 4 , the CPU  20  calculates the difference “C” (=B−A) from the new information registration time “A” for the specified marker display character string and the current time “B”. When the difference “C” is smaller than the set time “ 1 ”, the CPU  20  allows the specified marker display character string to be displayed with a marker in the display mode “1”. When the difference “C” is equal to or greater than the set time “ 1 ” and is smaller than the set time “ 2 ”, the CPU  20  allows the specified marker display character string to be displayed with a marker in the display mode “2”. And when the difference “C” is equal to or greater than the set time “ 2 ”, the CPU  20  allows the specified marker display character string to be displayed with a marker in the display mode “3”. 
         [0071]    Upon end of the above-described test mode processing, as illustrated in  FIG. 5 , the CPU  20  subsequently determines whether or not a touch operation is performed on the marker icon  101  on the main display  10  (Step S 8 ). Upon determination that no touch operation is performed on the marker icon  101  (NO in Step S 8 ), the CPU  20  ends the information display processing. 
         [0072]    On the other hand, when it is determined in Step S 8  that a touch operation is performed on the marker icon  101  (YES in Step S 8 ), the CPU  20  performs a marker mode processing (Step S 9 ). 
         [0073]    Specifically, as illustrated in  FIG. 8 , in the marker mode processing, the CPU  20  first controls the main display  10  to display a pen icon  104 , a color selection icon  105  and an eraser icon  106  (see  FIG. 9B ) on the end portion of the main display  10 , and determines whether or not an operation for ending the marker mode processing is performed (Step V 1 ). 
         [0074]    In this case, the pen icon  104  receives an operation for starting specification of the marker display character string. 
         [0075]    Further, the color selection icon  105  receives an operation for changing the marker color of the marker display character string, and is displayed with the same color as the marker color in the present embodiment. 
         [0076]    Furthermore, the eraser icon  106  receives an operation for canceling specification of the marker display character string. 
         [0077]    When it is determined in Step V 1  that the ending operation is not performed (NO in Step V 1 ), the CPU  20  determines whether or not a touch operation is performed on the color selection icon  105  (Step V 2 ). 
         [0078]    When it is determined in Step V 2  that a touch operation is performed on the color selection icon  105  (YES in Step V 2 ), the CPU  20  changes the display color of the color selection icon  105 , i.e., the marker color of the marker display character string (Step V 3 ), and then the processing goes to Step V 1  described above. Note that in the present embodiment, the CPU  20  changes the display color of the color selection icon  105  to red, yellow, blue and red sequentially in a switching manner. 
         [0079]    On the other hand, when it is determined in Step V 2  that no touch operation is performed on the color selection icon  105  (NO in Step V 2 ), the CPU  20  determines whether or not a touch operation is performed on the pen icon  104  (Step V 4 ). 
         [0080]    When it is determined in Step V 4  that a touch operation is performed on the pen icon  104  (YES in Step V 4 ), the CPU  20  receives a range specification operation for a character string in the display object text (Step V 5 ), and displays, as the marker display character string, the character string, for which the range specification has been performed, with a marker using the display color of the color selection icon  105  (Step V 6 ). 
         [0081]    Subsequently, the CPU  20  allows the position information of the marker display character string, the marker color thereof, and the time at the present moment to be accumulated and stored in the marker information database  85  so as to be associated with each other (Step V 7 ), and the processing goes to Step V 1  described above. 
         [0082]    On the other hand, when it is determined in Step V 4  that no touch operation is performed on the pen icon  104  (NO in Step V 4 ), the CPU  20  determines whether or not a touch operation is performed on the eraser icon  106  (Step V 8 ). Upon determination that no touch operation is performed on the eraser icon  106  (NO in Step V 8 ), the processing goes to Step V 1  described above. 
         [0083]    On the other hand, when it is determined in Step V 8  that a touch operation is performed on the eraser icon  106  (YES in Step V 8 ), the CPU  20  receives the touch operation performed for the marker display character string (Step V 9 ). 
         [0084]    Subsequently, for the marker display character string for which the touch operation has been performed, the CPU erases registration information from the marker information database  85  and cancels marker display (Step V 10 ), and then the processing goes to Step V 1  described above. 
         [0085]    Then, when it is determined in Step V 1  that the ending operation is performed (YES in Step V 1 ), the CPU  20  ends is the marker mode processing. Furthermore, in this case, the CPU  20  controls the main display  10  to display the marker icon  101  and the time lapse icon  102  on the end portion of the main display  10 . 
         [0086]    Then, upon end of the above-described marker mode processing, the CPU  20  ends the information display processing as illustrated in  FIG. 5 . 
       OPERATION EXAMPLE 
       [0087]    Next, referring to  FIGS. 9A to 11C , the foregoing information display processing will be specifically described. 
         [0088]    Note that in the following operation example, range specification is performed on character strings such as “          (daijo bukkyo)”, “          (jozabu bukkyo)”, “          (kasuto seido)” and “                    (herenizumu bunka)” as the marker display character strings in advance in the text of the “JUNIOR HIGH SCHOOL SOCIAL STUDIES GLOSSARY” (Step V 5 ), and the position information of each marker display character string, the marker color thereof, and the time at the present moment are accumulated and stored in the marker information database  85  so as to be associated with each other (Step V 7 ). 
         [0089]    In this state, first, as illustrated in  FIG. 9A , when a user performs a display instruction operation for the text including a headword “          (bukkyo)” in the dictionary database  90  of the “JUNIOR HIGH SCHOOL SOCIAL STUDIES GLOSSARY”(YES in Step S 1 ), this text is displayed in a full-screen manner, and the marker icon  101  and the time lapse icon  102  are displayed on the end portion of the main display  10 . 
         [0090]    Subsequently, it is determined that the time lapse icon  102  is not in the ON state (NO in Step S 3 ), the position information of the marker display character string included in the text of the “JUNIOR HIGH SCHOOL SOCIAL STUDIES GLOSSARY” is detected from the marker information database  85 , and the marker display character string indicated by the detected position information is displayed with a marker in the text using a marker color associated with the position information (Step S 4 ). Note that in  FIG. 9A , the character string such as “         ” is displayed with a red marker, the character string such as “          (shaka)” is displayed with a blue marker, and the character string such as “         ” is displayed with a yellow marker. 
         [0091]    Next, when the user performs a touch operation on the marker icon  101  (YES in Step S 8 ), the pen icon  104 , the color selection icon  105  and the eraser icon  106  are displayed on the end portion of the main display  10  as illustrated in  FIG. 9B , thereby enabling registration of the marker display character string (Step V 1 ). 
         [0092]    On the other hand, when the time lapse icon  102  is in the ON state in the status illustrated in  FIG. 9A  (YES in Step S 3 ), each marker display character string is displayed with a marker in the mode (i.e., with a density) which is changed in accordance with the time elapsed since the stored time of the position information as illustrated in  FIG. 9C  (Step S 5 ). Note that in  FIG. 9C , the difference “C” between the information registration time “A” for each marker display character string and the current time “B” is determined to be equal to or greater than the set time “ 1 ” (NO in Step T 6 ) and smaller than the set time “ 2 ” (YES in Step T 8 ), and each marker display character string is displayed with a marker in the display mode “ 2 ”, i.e., the mode in which the marker color is lower than the reference density (Step T 20 ). 
         [0093]    In this case, when the difference “C” between the information registration time “A” for the marker display character strings, such as the “         ” and “                   ” displayed with yellow markers, and the current time “B” is equal to or greater than the set time “ 2 ” (NO in Step T 6 , and NO in Step T 8 ), each of the marker display character strings is displayed with a marker in the display mode “3” (the mode in which a marker color density is increased so that each of the marker display character strings becomes a latent image) as illustrated in  FIG. 10A  (Step T 20 ). 
         [0094]    Subsequently, as illustrated in  FIG. 10B and 10C , the user performs a touch operation on the marker display character string “         ” displayed in a hidden manner as a latent image (YES in Step S 6 ), and a handwriting input “         ” is performed on the sub-display  11  for the specified marker display character string “                   ” specified by the touch operation (Step U 1 ); then, the handwritten character string is determined to be correct (CORRECT in Step U 2 ), and a message indicative of this fact is displayed. 
         [0095]    Then, as illustrated in  FIG. 11A , for the specified marker display character string “         ” registration information is erased from the marker information database  85 , and marker display is cancelled (Step U 3 ). 
         [0096]    Further, as illustrated in  FIG. 11B , the user performs a touch operation on the marker display character string “         ” displayed in a hidden manner as a latent image (YES in Step S 6 ), and performs a handwriting input “          (herenizumu bunmei)” on the sub-display  11  for the specified marker display character string “                   ” specified by the touch operation (Step U 1 ); then, the handwritten character string is determined to be incorrect (INCORRECT in Step U 2 ), and a message indicative of this fact is displayed. 
         [0097]    Then, as illustrated in  FIG. 11C , the stored time for the specified marker display character string “                   ” in the marker information database  85  is updated with the time at the present moment (at the determination moment) (Step U 4 ), the difference “C” (=B−A) between the new information registration time “A” for the specified marker display character string “         ” and the current time “B” is calculated, the difference “C” is determined to be smaller than the set time “ 1 ”, and the specified marker display character string “         ” is displayed with a marker in the display mode “1”. 
         [0098]    In the above-described electronic dictionary  1 , as illustrated in Step S 9  of  FIG. 5 , Steps T 1  to T 20  of  FIG. 6 ,  FIG. 9C  and  FIG. 10A , for example, the following operations are performed. When a character string in a displayed text is specified as a marker display character string based on a user&#39;s operation, position information of the marker display character string is stored, and a stored time of the position information is stored so as to be associated with the position information. In addition, when the text including the marker display character string is displayed, the marker display character string is displayed with a marker based on the position information of the stored marker display character string, and the mode of marker display for each marker display character string is changed in accordance with the time elapsed since the stored time for the marker display character string, thus making it possible to easily determine the marker display character string that has been registered for a long period of time. Accordingly, even when a plurality of marker display character strings exist in a text, it is possible to easily determine which marker display character string should be subjected to registration cancellation, and therefore, it is possible to easily cancel the registration of the marker display character string. 
         [0099]    Further, as illustrated in Step T 10  of  FIG. 6  and  FIG. 10A , for example, when the time elapsed since the stored time for a marker display character string is equal to or greater than a given period of time, the marker display character string is displayed with a marker so as to become a latent image, and therefore, the marker display character string, which has been registered for a long period of time, can be used for rote learning. 
         [0100]    Furthermore, as illustrated in Steps S 6  and S 7  of  FIG. 5 ,  FIG. 7 ,  FIGS. 10A to 10C , and  FIGS. 11A to 11C , for example, the following operations are performed. When one of marker display character strings, displayed as a latent image, is specified as a specified marker display character string based on a user&#39;s operation and an input operation for a character string is received from the user, it is determined whether or not the specified marker display character string and the inputted character string are substantially identical. Upon determination that the specified marker display character string and the inputted character string are substantially identical, information concerning the specified marker display character string is erased from the marker information database  85 , and upon determination that the specified marker display character string and the inputted character string are not substantially identical, the stored time for the specified marker display character string is stored as the time at the present moment in the marker information database  85 . Accordingly, a rote learning test for a marker display character string, which has been registered for a long period of time, can be carried out, and the registration of the marker display character string can be cancelled when the answer is correct in the rote learning test; on the other hand, the registration time of the marker display character string can be updated to the time at the present moment when the answer is incorrect in the rote learning test. Hence, as for a marker display character string for which the necessity for marker display is reduced, the registration thereof as a marker display character string can be cancelled; on the other hand, as for a marker display character string for which the necessity for marker display is still high, the marker display character string can be registered again as a newly registered marker display character string. 
         [0101]    Note that an embodiment to which the present invention is applicable is not limited to the foregoing embodiment, but appropriate changes may be made thereto without departing from the spirit of the present invention. 
         [0102]    For example, although the information display apparatus according to the present invention has been described as the electronic dictionary  1 , an apparatus to which the present invention is applicable is not limited to such a product but the present invention is applicable to all kinds of electronic apparatuses such as a mobile phone, a personal computer, a Personal Digital Assistant (PDA) and a game machine. Further, the information display program  81  according to the present invention may be stored in the recording medium  50 A, insertable into and removable from the electronic dictionary  1 , together with the content group  9 . 
         [0103]    Furthermore, although the description has been made on the assumption that a marker display character string, which is to be selected, is set in the display mode “3” when the difference “C” between the information registration time “A” and the current time “B” is equal to or greater than the set time “ 2 ”, but in such a case, information concerning the marker display character string may alternatively be erased from the marker information database  85 . In that case, for a marker display character string that has been registered for a long period of time, the registration thereof as a marker display character string can be automatically cancelled. In such an embodiment, as the display mode “1” or “2”, the mode in which a marker color density is increased so that the marker display character string becomes a latent image may be used. 
         [0104]    Moreover, the description has been made on the assumption that the stored time “A” for a marker display character string is stored and the difference “C” between the time “A” and the time “B” at the present moment is compared with the set times “ 1 ” and “ 2 ”, thus changing the display mode for marker display. However, the total number of operations performed in the electronic dictionary  1  at a stored time point may be stored, and a difference between the total number of operations at the stored time point and the total number of operations at the present time point may be compared with a given threshold value, thus changing the display mode. 
         [0105]    In addition, the description has been made on the assumption that information concerning a marker display character string including start and end positions, marker color and stored time of the marker display character string, is stored in the marker information database  85 . However, such information may be stored in association with a relevant item of each content in the content group  9 . 
         [0106]    Besides, the description has been made on the assumption that in the test mode processing, the CPU  20  makes a comparison between a character string inputted by a user and a specified marker display character string to determine whether the inputted character string is correct or incorrect. However, the CPU  20  may control the main display  10  to display a specified marker display character string after a character string has been inputted by a user, and may allow the user himself or herself to determine whether the inputted character string is correct or incorrect. In that case, upon input of a determination result by the user via the key group  2 , the CPU  20  will perform the processing of Step U 3  or U 4  based on the determination result.