Abstract:
A mobile telephone which can easily reach a target person and obtain a plurality of phone numbers thereof is disclosed. Registered phone numbers related to registered names are retrievably stored in a phone directory memory. A radial number memory stores a plurality of radial phone numbers which have been dialed. By selecting one of the radial phone numbers, a registered phone number related to the selected radial phone number is sequentially displayed to be redialed.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention generally relates to a portable or mobile communication device with a memory storing dialing information, and in particular to a telephone having a radial function and a redial method therefor. 
   2. Description of the Related Art 
   With the widespread use of mobile telephones, a growing number of people possess two or more telephones including a stationary telephone connected to a public telephone subscriber line. In such a situation, since a single person has a plurality of telephone numbers assigned thereto, there are cases where two or more telephone numbers are sequentially dialed to make contact with that person. 
   To make such a dialing operation easy, a telephone having the function of retrieving telephone numbers related to the last-dialed telephone number has been proposed in Japanese Patent Unexamined Publication No. 2 87751. This conventional telephone is provided with a redial key as well as a redial-next key. The redial key, as well known, is used to redial the last telephone number dialed. The redial-next key is used to retrieve telephone numbers related to the last-dialed number from a memory storing telephone numbers related to a specific telephone number. The retrieved telephone numbers can be read out sequentially at each push of the redial-next key. 
   In the case where the user wants to see telephone numbers related to a telephone number other than the last-dialed number, however, it is necessary to manually retrieve a phone directory. Such a manual search operation is inconvenient for the user. 
   SUMMARY OF THE INVENTION 
   An object of the present invention is to provide a mobile telephone and a redial method which can easily reach a desired person. 
   Another object of the present invention is to provide a mobile telephone which can easily find a plurality of registered phone numbers for a desired person. 
   According to the present invention, a mobile telephone having a redial function is comprised of: a display device; an input device for inputting a desired instruction; a first memory for retrievably storing a plurality of registered phone numbers related to a plurality of registered names; a second memory for storing a plurality of redial phone numbers which have been dialed; and a controller controlling such that a registered phone number related to a selected redial phone number is displayed on the display device to be redial ed depending on an instruction input through the input device. 
   One of the redial phone numbers stored in the second memory may be sequentially selected and displayed on the display device to be redialed depending on a first selection instruction. Further, a registered phone number related to a selected redial phone number may be selected and displayed on the display device to be redial ed depending on a second selection instruction. The first and second selection instructions are input through the input device. 
   Preferably, a registered phone number related to the selected redial phone number is sequentially selected from the first memory in predetermined order. 
   The input device may be comprised of a first redial key for producing the first selection instruction and a second redial key for producing the second selection instruction. 
   Alternatively, the input device may be comprised of a single redial key. The controller discriminates between the first selection instruction and the second selection instruction based on a length of time that the single redial key is depressed. 
   According to the present invention, a method for redialing a phone number in a mobile telephone having a redial function, comprises the steps of: a) retrievably storing a plurality of registered phone numbers related to a plurality of registered names in a phone directory memory; b) storing a plurality of redial phone numbers which have been dialed in a redial number memory; c) selecting one of the redial phone numbers stored in the redial number memory; d) retrieving a plurality of registered phone numbers related to a selected redial phone number from the phone directory memory; and e) redialing a selected one of the retrieved registered phone numbers depending on a calling instruction. 
   As described above, according to the present invention, a plurality of registered phone numbers for a single person can be easily retrieved and redial ed. Therefore, it can easily reach a desired person for a relatively short time and further easily find a plurality of registered phone numbers for a desired person by selecting the redial phone numbers stored in the redial number memory. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a block diagram showing a radio mobile telephone according to an embodiment of the present invention; 
       FIG. 2  is a schematic diagram showing an example of the contents of a phone directory memory provided in the embodiment; 
       FIG. 3  is a schematic diagram showing an example of the contents of a redial number memory provided in the embodiment; 
       FIG. 4  is a flowchart showing an operation of a redial key A provided in the embodiment; 
       FIG. 5  is a flowchart showing an operation of a redial key B provided in the embodiment; 
       FIG. 6  is a schematic diagram for explanation of a function of the redial key A; and 
       FIG. 7  is a schematic diagram for explanation of a function of the redial key B. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring to  FIG. 1 , there is shown a mobile telephone in accordance with the present invention. The mobile telephone is provided with a radio system  101  which transmits and receiver a radio signal to and from a radio base station (not shown) under control of a processor  102 . The processor  102  may be a program-controlled processor such as a central processing unit (CPU). A control program for the mobile telephone is stored in a read-only memory (not shown) and runs on the processor  102  to control all operations of the mobile telephone including a redialing operation as described later. 
   The mobile telephone is further provided with a phone directory memory  103  and a redial number memory  104 , which can be accessed by the processor  102 . As will be described later, the phone directory memory  103  retrievably stores a plurality of telephone numbers and the redial number memory  104  stores a predetermined number of telephone numbers which have been dialed so far. 
   A keypad  105  is provided on the main surface of a housing of the mobile telephone  10 . The keypad  105  is used by the user to do various instructions such as registering of a new telephone number, retrieval of a telephone number, and redial of a selected telephone number. In this embodiment, the keypad  105  includes a first redial key (A)  106 , a second redial key (B)  107 , and a calling key  108 . The redial key (A)  106  is used to select one of the telephone numbers stored in the redial number memory  104 . The redial key (B)  107  is used to read out telephone numbers related to the phone number selected by the redial key (A)  106  from the phone directory memory  103 . Necessary information is displayed on a display  109 , which may employ a liquid-crystal display (LCD). 
   The same function as a combination of the redial keys (A)  106  and (B)  107  can be also realized by simultaneous push of two or more different predetermined keys, which will result in reduced number of keys on the operation panel. Alternatively, the same function as a combination of the redial keys (A)  106  and (B)  107  can be realized by monitoring the length of time that a redial key is pushed. For example, a short-time push provides the redial function corresponding to the redial key (A)  106  and a long-time push provides the retrieval function corresponding to the redial key (B)  107 . In this case, only one redial key can provide the same function as a combination of the redial keys (A)  106  and (B)  107 . 
   Referring to  FIG. 2 , the phone directory memory  103  stores an M×N relational table consisting of a registered name field and N registered number fields. It is assumed that the phone directory memory  103  stores a total of M persons whose names are NAME 1 , NAME 2 , . . . NAME M , respectively, each registered name having a plurality of telephone numbers related thereto. For example, the registered name NAME 2  has N phone numbers TEL 21 , TEL 22  . . . TEL 2N . As described later, if any phone number for a registered name is selected as a key word, then the other phone numbers related to the selected phone number can be read out and displayed on the display  109 . In the case of the registered name NAME 2 , specifically, if the phone numbers TEL 21  is selected from the redial number memory  104 , then the other phone numbers TEL 22 , . . . TEL 2N  can be sequentially displayed at each push of the redial key (B)  107 . 
   Referring to  FIG. 3 , the redial number memory  104  stores a plurality of phone numbers which have been dialed. Here, the redial number memory  104  stores L phone numbers RN 1 -RN L , which are sequentially selected at each push of the redial key (A)  106 . 
   The processor  102  controls the redial number memory  104  such that both successful and unsuccessful phone numbers are written while automatically deleting the oldest phone number when the redial number memory  104  is full. Alternatively, as to unsuccessful phone number, only the last-dialed one may be stored in the redial number memory  104 , which results in memory saving. Even when a phone number has been successfully redial ed, it is preferable that the successful phone number is left in the redial number memory  104  for later confirmation. 
   In the embodiment, there is provided a link between the redial key (A)  106  and the redial key (B)  107 . First, one of the stored phone numbers RN 1 -RN L  is selected as a desired phone number by the user operating the redial key (A)  106 . Thereafter, by pushing the redial key (B)  107 , the processor  102  searches the phone directory memory  103  according to the phone number selected by the redial key (A)  106  and then sequentially displays the found phone numbers related to the selected phone numbers are sequentially displayed. 
   REDIAL NUMBER SELECTION 
   Referring to  FIG. 4 , when detecting a push of the redial key (A)  106  (YES in step  3401 ), it is determined whether one of the redial numbers stored in the redial number memory  104  has been already selected (step S 402 ). If one redial number has been already selected and displayed on the display  109  (YES in step S 402 ), then a next redial number following the one redial number in the redial number memory  104  is selected as a redial candidate (step S 403 ). If no redial number is selected (NO in step S 402 ), then one of the redial numbers stored in the redial number memory  104  is selected (step S 404 ). The default may be the last-dialed redial number in the redial number memory  104 . 
   The selected redial number at the step S 403  or S 404  is displayed on the display  109  (step S 405 ) and then it is determined whether a push of the calling key  108  is detected (step S 406 ). If the calling key  108  is pushed (YES in step S 406 ), then the processor  102  controls the radio system  101  to perform the calling operation (step S 407 ). If the calling key  108  is not pushed (NO in step S 406 ), then the processor  102  waits for a push of the calling key  108 , the redial key (A)  106 , or the redial key (B)  107 . 
   If a push of the redial key (A)  106  is detected in the case of a redial number having been selected and displayed (YES in steps S 401  and S 403 ), a next redial number is selected. In this way, the redial numbers stored in the redial number memory  104  are sequentially selected at each push of the redial key (A)  106 . 
   As shown in  FIG. 6 , such a redial number selection operation is done according to the steps of FIG.  4 . More specifically, at each push of the redial key (A)  106 , the stored redial numbers are sequentially and cyclically selected and displayed in order presented as follows: RN 1  (default)→RN 2 →RN 3 → . . . →RN L →RN 1 →RN 2 → . . . The selected redial number RN SEL  is used to make a call or as a keyword to search for related phone numbers as described hereinafter. 
   RELATED NUMBER RETRIEVAL 
   Referring to  FIG. 5 , when detecting a push of the redial key (B)  107  (YES in step S 501 ), it is determined whether one of the redial numbers stored in the redial number memory  104  has been already selected (step S 502 ). If one redial number has been already selected and displayed on the display  109  (YES in step S 502 ), then the processor  102  searches the phone directory memory  103  for the selected redial number and then sequentially selects one of the found phone numbers related to the selected redial number (step S 503 ). 
   When the selected phone number at the step S 503  is displayed on the display  109  (step S 504 ), when a push of the redial key (B)  107  is not detected (NO in step S 501 ), or when no redial number is selected (NO in step S 502 ), it is determined whether a push of the calling key  108  is detected (step S 505 ). If the calling key  108  is pushed (YES in step S 506 ), then the processor  102  controls the radio system  101  to perform the calling operation (step S 506 ). If the calling key  108  is not pushed (NO in step S 506 ), then the processor  102  waits for a push of the calling key  108 , the redial key (A)  106 , or the redial key (B)  107 . 
   If a push of the redial key (B)  107  is detected in the case of a redial number having been selected and displayed (YES in steps S 501  and S 502 ), a next related phone number is selected. In this way, the related phone numbers stored in the phone directory memory  103  are sequentially selected at each push of the redial key (B)  107 . 
   As shown in  FIG. 7 , such a related number selection operation is done according to the steps of FIG.  5 . Assuming that a redial number RN SEL  is selected by the redial key (A)  106 , the processor  102  searches the phone directory memory  103  for the selected redial number RN SEL . Since the table stored in the phone directory memory  103  is a kind of database, the processor  102  retrieves a record (or a line of the table) consisting of a registered name and a plurality of registered phone numbers TEL 1  TEL N , one of which is the selected redial number RN SEL . Thereafter, at each push of the redial key (B)  107 , the processor  102  sequentially selects one of the retrieved phone numbers TEL 1 -TEL N  other than the selected redial number RN SEL  and a selected one is displayed in order presented as follows: TEL 1 →TEL 2 →TEL 3 → . . . →TEL N →TEL 1 →TEL 2 → . . . The selected phone number is used to make a call. 
   For example, in  FIG. 2 , it is assumed that one phone number TEL 22  is selected as a selected redial number RN SEL . In this case, the processor  102  retrieves the record of the registered name NAME 2  including the phone number TEL 22 . Thereafter, at each push of the redial key (B)  107 , the processor  102  sequentially selects one of the retrieved phone numbers TEL 21  and TEL 22 -TEL N , that is, the retrieved phone numbers are displayed in order presented as follows: TEL 21 →TEL 23 →TEL 24 → . . . →TEL 2N →TEL 21 →TEL 23 → . . . The selected phone number is used to make a call depending on the user&#39;s instruction. 
   In the case where the number of related phone numbers is different among the registered names, it is preferable that the number of related phone numbers for a selected registered name is displayed on the display  109 . This causes the user to check the presence or absence of a related phone number and the number of the related phone numbers, resulting in enhanced convenience in phone number selection.