Abstract:
According to one aspect of the invention, there is provided a mobile apparatus including: a mail storage unit configured to store a history of email communications; an address storage unit configured to store a first email address associated with a certain name and a second email address associated with the certain name and an additional identifier; and a display unit configured to display the certain name in a first manner to represent the first email address in the history; wherein the display unit is configured to display the certain name in a second manner to represent the second email address in the history.

Description:
[0001]    The entire disclosure of Japanese Patent Application No. 2008-078806 filed on Mar. 25, 2008, including specification, claims, drawings and abstract is incorporated herein by reference in its entirety. 
       BACKGROUND 
       [0002]    1. Field of the Invention 
         [0003]    One aspect of the present invention relates to a mobile apparatus capable of displaying a name corresponding to a mail address as mail information when the mail address has been deleted from an address book. 
         [0004]    2. Description of the Related Art 
         [0005]    Recently, while telecommunication terminals such as mobile phones are coming into wide use, infrastructure for performing communication using the communication terminals is consolidated and thus communication using the telecommunication terminals has been widely performed. A common mobile phone, which previously stores an address book including phone numbers or mail addresses indicating a communicating party, displays communication history such as sent and received mails on a basis of this information. However, when data stored in the address book is rewritten by changing mail addresses or the like, the communication history based on a content of the address book cannot be displayed. 
         [0006]    There has been proposed a more user friendly communication terminal device by making information of communication history accurate (see JP-A-2002-171332, for instance). In the communication terminal device, when a transmission/reception history of a mail or a phone call relating to a communicating party registered in a telephone directory data storage area is prepared, a flag showing an existence of the history corresponding to such telephone directory data is stored in the telephone directory data storage area respectively corresponding to the telephone directory data of the communicating party. When a name of the telephone directory data in the telephone directory data storage area is changed, whether there is a name needed to be changed in the history is determined and the name included in a correspondent history is updated to the changed name. 
         [0007]    In JP-A-2002-171332, when phone numbers or mail addresses stored in the address book are updated, the communication history or the like is reviewed to rewrite them into new information. When an old phone number or a mail address is deleted from the address book, the name included in such a communication history may be deleted. 
         [0008]    When a communicating party changes a mail address, the user updates the address book of the mobile phone. When the address book is updated to a new mail address, the old mail address is usually deleted from the address book. Accordingly, the mail address itself, instead of the name included in the address book, is displayed when the user views past transmission/reception mails. In this case, the user may not distinguish who is the transmission/reception mail received from or who is the transmission/reception mail transmitted to. Further, when the user views the address book including both the new mail address and the old mail address, the user may not distinguish which address is usable new mail address. 
       SUMMARY 
       [0009]    According to one aspect of the invention, there is provided a mobile apparatus including: a mail storage unit configured to store a history of email communications; an address storage unit configured to store a first email address associated with a certain name and a second email address associated with the certain name and an additional identifier; and a display unit configured to display the certain name in a first manner to represent the first email address in the history; wherein the display unit is configured to display the certain name in a second manner to represent the second email address in the history. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    Embodiment may be described in detail with reference to the accompanying drawings, in which: 
           [0011]      FIG. 1A  is an exemplary front view illustrating an open state of a mobile phone according to a first and a second embodiments of the invention; 
           [0012]      FIG. 1B  is an exemplary side view illustrating the open state of the mobile phone according to the first and the second embodiments; 
           [0013]      FIG. 2A  is an exemplary front view illustrating a close state of the mobile phone according to the first and the second embodiments; 
           [0014]      FIG. 2B  is an exemplary side view illustrating the close state of the mobile phone according to the first and the second embodiments; 
           [0015]      FIG. 3  is an exemplary functional block diagram illustrating a mobile phone according to the first embodiment; 
           [0016]      FIG. 4  is an exemplary data configuration diagram illustrating address book information according to the first embodiment; 
           [0017]      FIG. 5  is an exemplary flowchart illustrating a procedure of performing an address book updating process in the mobile phone according to the first embodiment; 
           [0018]      FIG. 6  is an exemplary data configuration diagram illustrating address book information according to the first embodiment; 
           [0019]      FIG. 7  is an exemplary flowchart illustrating a procedure of performing an address book managing process in the mobile phone according to the first embodiment; 
           [0020]      FIG. 8  is an exemplary diagram illustrating a display screen of a mail box in the mobile phone according to the first embodiment; 
           [0021]      FIG. 9  is an exemplary diagram illustrating a display screen of an address book in the mobile phone according to the first embodiment; 
           [0022]      FIG. 10  is an exemplary functional block diagram illustrating a mobile phone according to the second embodiment; 
           [0023]      FIG. 11A  is an exemplary data configuration diagram illustrating address book information according to the second embodiment; 
           [0024]      FIG. 11B  is an exemplary data configuration diagram illustrating updated-address book information according to the second embodiment; 
           [0025]      FIG. 12  is an exemplary flowchart illustrating a procedure of performing an address book updating process in the mobile phone according to the second embodiment; 
           [0026]      FIG. 13A  is an exemplary data configuration diagram illustrating address book information according to the second embodiment; 
           [0027]      FIG. 13B  is an exemplary data configuration diagram illustrating updated-address book information according to the second embodiment; and 
           [0028]      FIG. 14  is an exemplary flowchart illustrating a procedure of performing an address book managing process in the mobile phone according to the second embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
     First Embodiment 
       [0029]    A first embodiment of a mobile apparatus according to the invention will be described with reference to  FIG. 1A  to  FIG. 9 . As the mobile apparatus according to the first embodiment, a clamshell mobile phone  1  will be described by way of example.  FIG. 1A  is a front view illustrating an open state of the mobile phone  1 , and  FIG. 1B  is a side view illustrating the open state of the mobile phone  1 .  FIG. 2A  is a front view illustrating a close state of the mobile phone  1 , and  FIG. 2B  is a side view illustrating the close state of the mobile phone  1 . 
         [0030]    As shown in  FIG. 1A  to  FIG. 2B , the mobile phone  1  is formed of a rectangular plate-shaped upper casing  10  and a lower casing  11  having substantially the same shape as the upper casing  10  so that front faces thereof are covered with each other. The upper casing  10  and the lower casing  11  are hinge-coupled through a hinge portion  12 , and the upper casing  10  is formed to freely swing around the hinge portion  12  in a direction indicated by an arrow X shown in  FIG. 1A  by a predetermined degree with respect to the lower casing  11 . The mobile phone  1  is changed from the close state to the open state or from the open state to the close state by rotating the upper casing  10  with respect to the lower casing  11 . 
         [0031]    A display  13  for displaying input characters or images, a address book, a transmitted or received mail, etc. and a speaker for outputting sound are provided on an inner face (facing to the lower casing  11 ) of the upper casing  10 . When the mobile phone  1  is in the close state, the display  13  and the speaker  14  are not exposed to the outside since they are covered with the lower casing  11 . However, when the mobile phone  1  is changed to the open state by rotating the upper casing  10  with respect to the lower casing  11 , the display  13  and the speaker  14  are exposed to the outside. 
         [0032]    For example, operation keys  15  such as a cross key for moving a cursor up, down, left, and right, numeral keys for inputting numerals, and a sending key for performing a sending process are provided on the inner face (facing to the upper casing  10 ) of the lower casing  11 . The lower casing  11  is provided with a microphone  16  for collecting sound. When the mobile phone  1  is in the close state, the operation keys  15  and the microphone  16  are not exposed to the outside since they are covered with the upper casing  10 . However, when the mobile phone  1  is changed to the open state by rotating the upper casing  10  with respect to the lower casing  11 , the operation keys  15  and the microphone  16  are exposed to the outside. 
         [0033]    Functions of the mobile phone  1  will be described with reference to a functional block diagram shown in  FIG. 3 . As shown in  FIG. 3 , the mobile phone  1  includes a main control unit  20 , a power supply circuit unit  21 , an operation input control unit  22 , a display control unit  23 , a sound control unit  24 , a communication control unit  25 , and a storage unit  26 , which are connected to each other by a bus. 
         [0034]    The main control unit  20  having a Central Processing Unit (CPU) performs general controls of the mobile phone  1 , an address management process, a mail display control process, and the other various operation processes and control processes. The power supply circuit unit  21  switches power ON/OFF based on user&#39;s input at the operation keys  15 . In a power-ON state, the power supply circuit unit  21  supplies electric power from a power supply source (battery, etc.) to each unit, thereby operating the mobile phone  1 . 
         [0035]    The operation input control unit  22  has an input interface for the operation keys  15 , and transmits signals input at the operation keys  15 , to the main control unit  20 . The display control unit  23  has an interface for the display  13 , and displays document data or image data on the display  13  based on the control of the main control unit  20 . 
         [0036]    The sound control unit  24  generates an analog sound signal from sound collected by the microphone  16  based on the control of the main control unit  20 , and converts the analog sound signal into a digital sound signal. When the sound control unit  24  receives a digital sound signal, the sound control unit  24  converts the digital sound signal into an analog sound signal and outputs the analog sound signal from the speaker  14 , based on the control of the main control unit  20 . 
         [0037]    The communication control unit  25  performs spectrum despreading on a received signal received from a base station (not shown) through an antenna  25   a  to restore data based on the control of the main control unit  20 . The data is transmitted to the sound control unit  24  and is output from the speaker  14 , the data is transmitted to the display control unit  23  and is displayed on the display  13 , or the data is stored in the storage unit  26 , by the instruction of the main control unit  20 . When the communication control unit  25  receives the sound data collected by the microphone  16 , the data input at the operation keys  15 , or the data stored in the storage unit  26 , the communication control unit  25  performs spectrum despreading on the data and transmits the data to the base station through the antenna  25   a , based on the control of the main control unit  20 . 
         [0038]    The storage unit  26  includes a Read Only Memory (ROM) for the processes performed by the main control unit  20 , a hard disk, a non-volatile memory, a database, a Random Access Memory (RAM) for temporarily storing data used for the processes performed by the main control unit  20 , and the like. Programs for an address book updating process or a mail display control process performed by the main control unit  20  are stored, for example, in the ROM. 
         [0039]    The storage unit  26  has an address storage unit  26   a  for storing address book information  30 . In the address book information  30 , phone numbers or mail addresses used when a user makes a phone call and transmits or receives a mail using the mobile phone  1  are stored corresponding to names. As shown in  FIG. 4 , in the address book information  30 , at least name information  30   a  indicating names, phone number information  30   b  indicating phone numbers, and mail address information  30   c  indicating mail addresses correspond to each other. 
         [0040]    For example, in the address book information  30  shown in  FIG. 4 , the phone number information  30   b  of “090-1111-1111” and the mail address information  30   c  of “ichiro@abc.jp” correspond to the name information  30   a  of “Ichiro TOSHIBA”, and the phone number information  30   b  of “090-2222-2222” and the mail address information  30   c  of “jiro@abc.jp” correspond to the name information  30   a  of “Jiro TOSHIBA”. 
         [0041]    The storage unit  26  has a mail storage unit  26   b  for storing mail information transmitted and received by the mobile phone  1 . The mail information includes transmission date and time, a transmission destination, a mail content, an attached file, and the like about the transmitted mail corresponding to each other. In addition, the mail information includes reception date and time, a transmission source, a mail content, an attached file, and the like about the received mail corresponding to each other. 
         [0042]    When the phone numbers or mail addresses stored as the address book information  30  need to be changed, the user inputs new information at the operation keys  15  to update the information. When the user inputs a new phone number or mail address, the mobile phone  1  performs an address book updating process for storing the input information in the address book storage unit  26   a.  A procedure of the address book updating process performed by the mobile phone  1  will be described with reference to a flowchart shown in  FIG. 5 . Hereinafter, a word of “Step” is omitted in description, for example, “Step S 101 ” is represented by “S 101 ”. 
         [0043]    When a user changes a phone number or a mail address stored as the address book information  30  using the mobile phone  1 , the user inputs the information at the operation keys  15 . Hereinafter, it is assumed that the user inputs a mail address by way of example. First, the main control unit  20  determines whether or not a user input a new mail address (S 101 ). When a new mail address is not input (S 101 : No), the main control unit  20  does not perform the address book updating process and waits as it is. 
         [0044]    When a new mail address was input (S 101 : Yes), the main control unit  20  stores a character string in which, for example, “_old” is added to an end of the mail address information  30   c  previously stored in the address book storage unit  26   a , as the mail address information  30   c  (S 103 ). The main control unit  20  stores the mail address including the “_old” added in Step S 103 , in the address book storage unit  26   a  (S 105 ). In this embodiment, “_old” is exemplified as an additional identifier, however other character strings can be used as the additional identifier. 
         [0045]    In Step S 103 , when there are a plurality of the previously stored mail address information  30   c , the “_old” may be added after a screen for selecting an address to be added by “_old” from the previously stored mail addresses is displayed and a selecting operation is received, so that a mail address to be added by an identifier indicating an old address is selected. 
         [0046]    For example, in Step S 101 , when a user inputs “jiro_new@abc.jp” as a new mail address of “Jiro TOSHIBA”, in the address book storage unit  26   a , “jiro@abc.jp_old”, which is formed by adding “_old” to the end of “jiro@abc.jp” that is the mail address information  30   c  corresponding to the name information  30   a  of “Jiro TOSHIBA”, is stored corresponding to the name information  30   a  of “Jiro TOSHIBA” in the address book storage unit  26   a , as the mail address information  30   c , as shown in  FIG. 6 . 
         [0047]    The main control unit  20  stores the new mail address corresponding to the name information  30   a  stored in Step S 101  as the mail address information  30   c , in the address book storage unit  26   a  (S 107 ). 
         [0048]    For example, In Step S 101 , the user inputs “jiro_new @abc.jp” as a new mail address of “Jiro TOSHIBA”, in the address book storage unit  26   a , the newly input “jiro_new@abc.jp” as the mail address information  30   c  corresponding to the name information  30   a  of “Jiro TOSHIBA” is stored corresponding to the name information  30   a  of “Jiro TOSHIBA” in the address book storage unit  26   a , as the new mail address information  30   c , as shown in  FIG. 6 . 
         [0049]    As described above, when a phone number or mail address stored as the address book information  31  is rewritten, the mobile phone  1  stores a previous (before change) phone number or mail address added by an identifier such as “_old” in the address book storage unit  26   a.    
         [0050]    A method for adding the identifier such as “_old” to the mail address before change is not limited to the method shown in  FIG. 5 . For example, in the step of displaying the name information  30   a  of “Jiro TOSHIBA”, when a menu is opened and an item of “set as an old address” is selected, “a control that the main control unit  20  stores what the mail address information  30   c  previously stored in the address book storage unit  26   a  added by, for example, “_old” to the end, as the mail address information  30   c ” may be performed in Step S 103  shown in  FIG. 5 . 
         [0051]    When the mobile phone  1  displays a mail box based on the mail information stored in the mail storage unit  26   b , the mobile phone  1  performs a mail display control process for displaying information representing a mail content and a transmission source or transmission destination based on the address book information  30  stored in the address book storage unit  26   a . A procedure of the mail display control process performed by the mobile phone  1  will be described with reference to a flowchart shown in  FIG. 7 . 
         [0052]    To check a mail box, the user inputs an instruction to display the mail box at the operation keys  15 . First, the main control unit  20  determines whether or not the displaying of the mail box was instructed by the user (S 201 ). When the displaying of the mail box was not instructed (S 201 : No), the main control unit  20  does not display the mail box and waits as it is. 
         [0053]    When the displaying of the mail box was instructed (S 201 : Yes), the main control unit  20  retrieves mail information from the mail storage unit  26   b  (S 203 ). The main control unit  20  searches the address book storage unit  26   a  based on the mail address of the mail information retrieved in Step S 203  (S 205 ). 
         [0054]    The main control unit  20  determines whether or not there is a mail address corresponding to the mail address included in the mail information in the address book storage unit  26   a  (S 207 ). In this case, when “_old” is added to the mail address in the address book storage unit  26   a , the correspondence is determined as the address not including “_old”. When there is no corresponding mail address in the address book storage unit  26   a  (S 207 : No), the main control unit  20  displays the mail address as it is in the mail box since the mail address included in the mail information is not stored as the address book information  30  (S 209 ). 
         [0055]    Shown in  FIG. 8 , for example, when the mail information includes a mail address of “abc@abc.jp”, “abc@abc.jp” is displayed as it is in the mail box in Step S 209  since the mail address is not stored in the address book storage unit  26   a.    
         [0056]    When there is a mail address corresponding to the mail address included in the mail information in the address book storage unit  26   a  (S 207 : Yes), the main control unit  20  determines whether or not “_old” is added to the corresponding mail address (S 211 ). That is, in the phone numbers or mail addresses stored in the address book storage unit  26   a , when there was a rewritten phone number or mail address in Step S 101  to S 107 , “_old” has been added to the end thereof. 
         [0057]    When “_old” is not added thereto (S 211 : No), the main control unit  20  retrieves the name information  30   a  from the address book storage unit  26   a  based on the mail address included in the mail information since the mail address included in the mail information is stored in the address book storage unit  26   a  and is the present used mail address (S 213 ). The main control unit  20  displays the name retrieved in Step S 213 , as a transmission source or transmission destination of the mail box (S 215 ). 
         [0058]    As shown in  FIG. 8 , for example, when the mail information includes a mail address of “saburo@abc.jp”, the mail information  30   a  is retrieved in Step S 213  since the mail address corresponds to the name information  30   a  of “Saburo TOSHIBA” in the address book storage unit  26   a . In Step S 215 , the name of “Saburo TOSHIBA” is displayed in the mail box. 
         [0059]    When “_old” is added thereto (S 211 : Yes), the main control unit  20  retrieves the name information  30   a  from the address book storage unit  26   a  based on the mail address included in the mail information since the mail address included in the mail information was stored once in the address book storage unit  26   a  but has been rewritten (S 217 ). The main control unit  20  displays the name retrieved in Step S 213  as a transmission source or transmission destination of the mail box by changing a typeface thereof or the like (S 219 ). 
         [0060]    As shown in  FIG. 8 , for example, when the mail information includes a mail address of “ichiro@abc.jp”, the name information  30   a  is retrieved in Step S 217  since the mail address having “_old” added thereto corresponds to the name information  30   a  of “Ichiro TOSHIBA” in the address book storage unit  26   a . In Step S 219 , for example “OLD” is added to the name of the “Saburo TOSHIBA” and the name is displayed in italics. 
         [0061]    As described above, when the phone number or mail address stored as the address book information  30  are rewritten, the mobile phone  1  adds the identifier to the previous phone number or mail address and stores them. Accordingly, in the mail box, even an unusable old mail address can be displayed in a form of a name. In this case, the name may be displayed by changing a color or adding a symbol to its top so that the user can recognize that the mail address represented by the name is the old mail address. 
         [0062]    For example, even when the old mail address of “Jiro TOSHIBA” is deleted from the address book information  30 , the user can see the name of “Jiro TOSHIBA” in the mail box. “OLD”, a symbol, a picture, or the like may be added in a vicinity of the name, or a displayed color or typeface thereof may be changed so that the user can recognize the mail address as the old mail address. 
         [0063]    When the user updates the address book of the mobile phone  1  by changing mail addresses of user&#39;s acquaintance, a new mail address may be added to the address book with the original mail address left as it is. Even in this method, when the past history of transmission/reception mails is displayed, it is possible to display a name corresponding to the old mail address. However, in this method, the old mail address that cannot be used any longer remains in the address book. Accordingly, when the user tries to send a mail actually, the user cannot distinguish a usable mail address from the mail addresses. In contrast, in the embodiment, an identifier (“_old”, etc.) is added to the old mail address, and thus the user can distinguish the old mail address. 
         [0064]    As the first embodiment, the procedure of displaying the mail box has been described, but the invention is not limited thereto. Even in the case of displaying the address book, the rewritten old phone number or mail address (phone number or mail address having “_old” added thereto) is displayed by adding an identifier or by changing a typeface. As shown in  FIG. 9 , for example, “OLD” is added in the vicinity of “jiro@abc.jp” that is the old mail address having “_old” added thereto in the address book information  30 , and then the address book is displayed. 
         [0065]    According to the first embodiment, even when the phone number or mail address is rewritten in the address book, the user can distinguish a transmission source or transmission destination of the past transmission/reception mail by storing the phone number or mail address before change with the identifier added thereto. 
       Second Embodiment 
       [0066]    A second embodiment of the mobile apparatus according to the invention will be described with reference to  FIG. 10  to  FIG. 14 . The same reference numerals and signs are given to the same configurations as the first embodiment, and the repeated description is omitted. As shown in  FIG. 1A  to  FIG. 2B , a mobile phone  1 A according to the second embodiment has the same configuration as the mobile phone  1  according to the first embodiment. Similarly with the mobile phone  1 , as shown in  FIG. 3 , the mobile phone  1 A according to the second embodiment includes the main control unit  20 , the power supply circuit unit  21 , the operation input control unit  22 , the display control unit  23 , the sound control unit  24 , the communication control unit  25 , and a storage unit  26 A, which are connected to communicate with each other. 
         [0067]    The storage unit  26 A has an address book storage unit  26   a  for storing address book information  31 . In the address book information  31 , phone numbers or mail addresses used when a user makes a phone call and transmits or receives a mail using the mobile phone  1  are stored corresponding to names. As shown in  FIG. 11A , in the address book information  31 , at least name information  31   a  indicating names, phone number information  31   b  indicating phone numbers, and mail address information  31   c  indicating mail addresses correspond to each other. 
         [0068]    For example, in the address book information  31  shown in  FIG. 11A , the phone number information  31   b  of “090-1111-1111” and the mail address information  31   c  of “ichiro@abc.jp” correspond to the name information  31   a  of “Ichiro TOSHIBA”, and the phone number information  31   b  of “090-2222-2222” and the mail address information  31   c  of “jiro_new@abc.jp” correspond to the name information  31   a  of “Jiro TOSHIBA”. 
         [0069]    The storage unit  26 A has  1  mail storage unit  26   b  for storing mail information transmitted and received by the mobile phone  1 A. The mail information includes transmission date and time, a transmission destination, a mail content, an attached file, and the like about the transmitted mail corresponding to each other. In addition, the mail information includes reception date and time, a transmission source, a mail content, an attached file, and the like about the received mail corresponding to each other. 
         [0070]    The storage unit  26 A has a change address book storage unit  26   c  for storing change address book information  32 . In the change address book information  32 , the phone numbers or mail addresses before change are stored corresponding to names, with respect to the changed phone number or mail address in the address book information  31 . As shown in  FIG. 11B , in the change address book information  32 , at least name information  32   a  indicating names, phone number information  32   b  indicating phone numbers, and mail address information  32   c  indicating mail addresses correspond to each other. 
         [0071]    For example, in the change address book information  32  shown in  FIG. 11B , the mail address information  32   c  of “jiro@abc.jp” corresponds to the name information  32   a  of “Jiro TOSHIBA”. This indicates that the mail address “jiro@abc.jp” of “Jiro TOSHIBA” stored in the address book information  32  has been already changed to a new mail address. 
         [0072]    When the phone numbers or mail addresses stored as the address book information  31  needs to be changed, the user inputs new information at the operation keys  15  to update the information. When the user inputs a new phone number or mail address, the mobile phone  1 A performs an address book updating process for storing the input information in the address book storage unit  26   a . A procedure of the address book updating process performed by the mobile phone  1 A will be described with reference to a flowchart shown in  FIG. 12 . 
         [0073]    When a user changes a phone number or mail address stored as the address book information  31  using the mobile phone  1 A, the user inputs the new phone number or mail address at the operation keys  15 . Hereinafter, it is assumed that the user inputs a new mail address by way of example. First, the main control unit  20  determines whether or not a user input a new mail address (S 301 ). When a new mail address was not input (S 301 : No), the main control unit  20  does not perform the address book updating process and waits as it is. 
         [0074]    When a new mail address Was input (S 301 : Yes), the main control unit  20  stores the mail address information  31   c  before change previously stored in the address book storage unit  26   a , corresponding to the name information  31   a  corresponding to the mail address information  31   c , as the change address book information  32  in the change address book storage unit  26   c  (S 303 ) The main control unit  20  the mail information input in Step S 301  as the mail address information  31   c , corresponding to the name information  31   a , in the address book storage unit  26   a  (S 305 ). 
         [0075]    For example, in Step S 301 , when a user inputs a new mail address “saburo_new@abc.jp” for “Saburo TOSHIBA”, “saburo_new@abc.jp” that is the newly input mail address corresponds to the name information  31   a  of “Saburo TOSHIBA”, as the mail address information  31   c  in the address book information  31 , as shown in  FIG. 13A . As shown in  FIG. 13B , in the change address book information  32 , “saburo@abc.jp” that is the mail address before change corresponds to the name information  32   a  of “Saburo TOSHIBA”, as the mail address information  31   c.    
         [0076]    As described above, when the phone number or mail address stored as the address book information  31  is rewritten, the mobile phone  1 A stores the phone number or mail address before change corresponding to the name in the change address book storage unit  26   c  that is a dedicated database. 
         [0077]    The mobile phone  1 A displays a mail box based on the mail information stored in the mail storage unit  26   b , the mobile phone  1 A performs a mail display control process for displaying information representing a mail content and a transmission source or transmission destination based on the address book information  31  or the change address book information  32  stored in the address book storage unit  26   a . A procedure of the mail display control process performed by the mobile phone  1 A will be described with reference to a flowchart shown in  FIG. 14 . 
         [0078]    To check a mailbox, a user inputs an instruction to display the mail box at the operation keys  15 . First, the main control unit  20  determines whether or not the displaying of the mail box is instructed by the user (S 401 ). When the displaying of the mail box is not instructed (S 401 : No), the main control unit  20  does not display the mail box and waits as it is. 
         [0079]    When the displaying of the mail box is instructed (S 401 : Yes), the main control unit  20  retrieves mail information from the mail storage unit  26   b  (S 403 ). The main control unit  20  searches the address book storage unit  26   a  based on the mail address of the mail information retrieved in Step S 403  (S 405 ). 
         [0080]    The main control unit  20  determines whether or not there is a mail address corresponding to the mail address included in the mail information in the address book storage unit  26   a  (S 407 ). When there is a mail address corresponding to the mail address included in the mail information in the address book storage unit  26   a  (S 407 : Yes), the main control unit  20  retrieves the name information  31   a  from the address book storage unit  26   a  based on the mail address included in the mail information since the mail address included in the mail information is stored in the address book storage unit  26   a  and is the present used mail address (S 409 ) The main control unit  20  displays the name retrieved in Step S 409 , as a transmission source or transmission destination of the mail box (S 411 ). 
         [0081]    As shown in  FIG. 8 , for example, when the mail information includes a mail address of “ichiro@abc.jp”, the name information  30   a  is retrieved in Step S 409  since the mail address corresponds to the name information  31   a  of “Ichiro TOSHIBA” in the address book storage unit  26   a . In Step S 411 , the name of “Ichiro TOSHIBA” is displayed in the mail box. 
         [0082]    When there is no corresponding mail address in the address book storage unit  26   a  (S 407 : No), the main control unit  20  searches the change address storage unit  26   c  based on the mail address included in the mail information since the mail address included in the mail information was stored once in the address book storage unit  26   a  but may have been rewritten (S 413 ). 
         [0083]    The main control unit  20  determines whether or not there is a mail address corresponding to the mail address included in the mail information in the change address book storage unit  26   c  (S 415 ). When there is a mail address corresponding to the mail address included in the mail information in the change address book storage unit  26   c  (S 415 : Yes), the main control unit  20  retrieves the name information  32   a  corresponding to the mail address included in the mail information from the change address book storage unit  26   c  (S 417 ). The main control unit  20  displays the name retrieved in Step S 417  as a transmission source or transmission destination of the mail box by changing the typeface thereof or the like (S 419 ). 
         [0084]    As shown in  FIG. 8 , for example, when the mail information includes a mail address of “jiro@abc.jp”, the name information  32   a  is retrieved in Step S 417  since the mail address corresponds to the name information  32   a  of “Jiro TOSHIBA” in the change address book storage unit  26   c . In Step S 419 , for example “OLD” is added to the name of the “Jiro TOSHIBA” and the name is displayed in Italics. 
         [0085]    When there is no mail address corresponding to the mail address included in the mail information in the change address book storage unit  26   c  (S 415 : No), the main control unit  20  displays the mail address as it is in the mail box since the mail address included in the mail information is not stored as the address book information  31  or the change address book information  32  (S 421 ). 
         [0086]    Shown in  FIG. 8 , for example, when the mail information includes a mail address of “abc@abc.jp”, “abc@abc.jp” is displayed as it is in the mail box in Step S 421  since the mail address is not stored in the address book storage unit  26   a.    
         [0087]    As described above, in the mobile phone  1 A, when the phone number or mail address stored as the address book information  31  are rewritten, the phone number or mail address before change are stored corresponding to the name in the change address book storage unit  26   c  that is a dedicated database. Accordingly, even when the mail address displayed in the mail box was deleted from the address book information  31 , the mail address is changed to the name to be displayed in the mail box. In this case, the name maybe displayed by changing a color or adding a symbol so that the user can recognize the old mail address. 
         [0088]    As the second embodiment, the procedure of displaying the mailbox has been described, but the invention  4 s not limited thereto. Even in the case of displaying the address book, the rewritten old phone number or mail address (phone number or mail address stored in the change address book information  32 ) is displayed by adding an identifier or changing a typeface. As shown in  FIG. 9 , for example, “OLD” is added in the vicinity of “jiro@abc.jp” that is the old mail address stored in the change address book information  32 , and then the address book is displayed. 
         [0089]    According to the second embodiment, even when the phone number or mail address is rewritten in the address book, the user can distinguish a transmission source or transmission destination of the past transmission/reception mail by storing the phone number or mail address before change in the dedicated database. 
         [0090]    Generally, in the method of adding the identifier of “_old” as described in the first embodiment, it is not necessary to prepare a new database  555 , and the method can be applied to the system of the known address book. Accordingly, even when the address book is transmitted to the other mobile phone or personal computer, the old mail address can be also transmitted. Thus, a user can know that the mail address is the old mail address by checking the mail address. Therefore, the mobile phone according to the invention is very compatible with the other mobile phone or personal computer not having any function according to the invention. 
         [0091]    There are may users who frequently change mail addresses of mobile phones, and there are many mail addresses by which a user cannot be identified. Even in such a case, a history of mail transmission and reception can be displayed using the names or the like stored in the address book. Accordingly, it is very advantageous that the user can immediately distinguish who is the transmission/reception mail received from or who is the transmission/reception mail transmitted to. 
         [0092]    In the invention, the mobile phones  1  and  1 A have been described, but the invention is not limited thereto and may be applied to any communication terminals such as a Personal Handyphone System (PHS) and a Personal Digital Assistance (PDA)