Abstract:
In a selective call receiver, a plurality of received messages are stored onto a message memory until the message memory is full. The received messages have designated degrees, respectively, which are each designated by instructions of a user. When a new received message is received, an earlier received message having the lowest designated degree is retrieved among the received messages stored in the memory and then the new received message is written over the earlier received message having the lowest designated degree.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention generally relates to a selective call receiver, and in particular to a method and system for managing received messages which are stored in a message memory.  
           [0003]    2. Description of the Related Art  
           [0004]    A selective call receiver has been widely used for various purposes and, especially, a small-sized and lightweight selective call receiver called a pager is suitable for being taken on the road. A basic function of the selective call receiver is to indicate by beep sound, vibration, or light the incoming call and then to display a received message on an liquid-crystal display (LCD). The received message is stored in a message memory and is read out from the message memory to be displayed on screen according to key operations of a user.  
           [0005]    A received message is usually stored onto the message memory until it becomes full. When the message memory reaches capacity, the oldest message is automatically deleted and the latest message is stored. Therefore, a necessary message may be deleted without the user&#39;s knowing. On the other hand, in the case where a necessary message is protected, the message is stored in the message memory for indefinitely long time periods until it is deleted by the user consciously, resulting in unnecessarily reduced memory area. Therefore, it is important to decide which message is to be deleted in terms of effective use of the message memory. For this purpose, a selective call receiver having a function of erasing unwanted messages from the message memory by user&#39;s operations is disclosed in Japanese Patent Unexamined Publication No. 59-226994. A message is displayed on screen and the user decides whether the message is to be deleted.  
           [0006]    SUMMARY OF THE INVENTION  
           [0007]    An object of the present invention is to provide a message management method which prevents an important message from erroneous deletion with the effective use of memory.  
           [0008]    Another object of the present invention is to provide a selective call receiver which achieves the effective use of a message memory by retaining only important messages.  
           [0009]    According to the present invention, a plurality of received messages are stored onto a memory until the memory is full. The received messages have designated degrees, respectively, which are each designated by instructions of a user. When a new received message is received, an earlier received message having a lowest designated degree is retrieved among the received messages stored in the memory and then the new received message is stored over the earlier received message having the lowest designated degree. Each of the designated degrees may be one of a plurality of importance degrees or one of a locking degree and a plurality of importance degrees which are lower than the locking degree. Since the message having the lowest degree is erased and the new message is written, an important message is prevented from erroneous deletion and the effective use of memory is achieved. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    [0010]FIG. 1 is a functional block diagram showing an embodiment of a radio selective call receiver according to the present invention;  
         [0011]    [0011]FIG. 2 is a flowchart showing a write-over routine of an embodiment of a message management method according to the present invention;  
         [0012]    [0012]FIG. 3 is a flowchart showing a lock and importance designation routine of the embodiment of the message management method; and  
         [0013]    [0013]FIG. 4 is a schematic diagram showing an example of a display screen according to the embodiment of the message management method.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0014]    Referring to FIG. 1, there is shown a selective call receiver in accordance with the present invention. The selective call receiver is provided with a radio system  101  which receives a radio signal from a radio base station (not shown) of a selective calling system through an antenna. The radio system  101  includes a demodulator which demodulates the received radio signal into a baseband signal. After the waveform of the baseband signal is shaped by a waveform shaping circuit  102 , the baseband signal is transferred to a decoder  103  and a sync circuit  105 .  
         [0015]    The decoder  103  decodes the baseband signal into received data according to a sync timing signal received from the sync circuit  105  and compares a selective calling number included in the received data with an identification (ID) number which is previously stored in an ID ROM  102 . The sync circuit  105  detects synchronization from the baseband signal and produces the sync timing signal using a reference oscillation signal which is generated by a quartz oscillator  106 . When the selective calling number is identical to the ID number, that is, an incoming call occurs, a received message data MSG included in the received data is stored onto a message memory  108  together with lock or importance designation information under the control of a processor  107 , which will be described in detail. The processor  107  controls the receiver operations according to a program stored in a program ROM  109 .  
         [0016]    The message memory  108  stores a plurality of received messages MSG 1 , MSG 2 , . . . , which are each accompanied by degrees of importance, D 1 , D 2 , . . . , or lock information in table form. For example, the highest degree of importance is represented by D=4 and the lowest degree of importance is rep resented by D=0 which means that neither lock nor importance is designated. The lock information YES or No may be indicated by a lock flag being 1 or 0. It is also possible that the lock flag and the degree of importance is combined into a designated degree. More specifically, the designated degree consists of the lock flag as themost significant bit (MSB) followed by the degree of importance D because the degree of the locking may be higher than any of the degrees of importance.  
         [0017]    The selective call receiver is further provided with a speaker driver  110  and a speaker  111  for informing a user of an incoming call. An LCD driver  112  and an LCD  113  are provided to display messages and other information on screen. Furthermore, the processor  107  is connected to an input controller  114  which controls a keypad  115  to receive instructions including lock and importance designation from the user. When an incoming call occurs, the processor  107  controls the speaker  111  to make a beep. Further, when receiving a read request from the keypad  115 , the processor  107  reads a designated message from the message memory  108  and then sends the message to the LCD driver  112  to display it on the LCD  113 .  
         [0018]    Referring to FIG. 2, when a selective calling number of the received data is coincident with the ID number, the processor  107  receives a received message MSG i  from the decoder  103  and displays the message MSG i  on the LCD  113  (step S 201 ). When receiving the received message MSG i , the processor  107  checks whether the message memory  108  is full (step S 202 ). In the case where the message memory  108  is full (YES of step S 202 ), the processor  107  searches the message memory  108  for the lowest degree of importance Dx of a message MSGx except a locked message and reads the address Ax of the lowest important message MSGx (step S 203 ). If two or more lowest important messages are found, the earliest one may be selected. In the case where the message memory  108  is not full (NO of step S 202 ), lock designation or importance designation is performed as will be described referring to FIG. 3. As described before, in the case where the lock information and the degree of importance is combined into a designated degree, the processor  107  can retrieve the lowest important message MSGx by only searching the designated degrees stored in the message memory  108 .  
         [0019]    Subsequently, when the lock designation is requested by the user (YES of step S 204 ), the lock designation is performed (step S 205 ). When the lock designation is not requested but the importance designation (NO of step S 204  and YES of step S 206 ), the importance designation is performed (step S 207 ). The lock designation routine (S 205 ) and the importance designation routine (S 207 ) will be described in detail referring to FIG. 3. After the lock designation or the importance designation is performed, the processor  107  writes the received massage MSGi over the address Ax of the lowest important message MSGx (step S 208 ). In this manner, when the message memory  108  is full, the lowest important message MSGx is deleted from the message memory  108  and the new message MSGi is written onto the message memory  108 .  
         [0020]    Referring to FIG. 3, when the message memory  108  is not full (NO of step S 202 ), the rock designation or the importance designation is performed. In the case where the lock designation is requested by the user (YES of step S 301 ), the lock designation steps S 302 -S 304  are performed. More specifically, when the user requests the locking of the message MSGi through the keypad  115 , the processor  107  transfers the lock information (YES) to an address ALi for lock information of the message memory  108  (step S 302 ). Further, the lock information is transferred to the LCD driver  112  (step S 303 ) and is displayed on the LCD  113  (step S 304 ) and thereby the user can confirm the locking of the message MSGi. After that, the message MSGi is stored at a message address Ai of the message memory  108  (step S 305 ).  
         [0021]    When the lock designation is not requested but the importance designation (NO of step S 301  and YES of step S 306 ), the importance designation steps S 307 -S 310  are performed. More specifically, when receiving the degree of importance Di of the message MSGi from the keypad  115  (step S 307 ), the processor  107  transfers the importance information Di to an address ADi for importance information of the message memory  108  (step S 308 ). Further, the importance information Di is transferred to the LCD driver  112  (step S 309 ) and is displayed on the LCD  113  (step S 310 ) and thereby the user can confirm the degree of importance Di given to the message MSGi. After that, the message MSGi is stored at a message address Ai of the message memory  108  (step S 305 ).  
         [0022]    When the importance designation is not requested (NO of step S 306 ), the message MSGi is stored at a message address Ai of the message memory  108  (step S 305 ) without lock or importance designation. In this case, the lowest degree of importance is given to the message MSGi. Therefore, if anew message is received in the case of the message memory  108  being full, the new message is written over that lowest important message MSGi.  
         [0023]    As shown in FIG. 4, as an example, the degree of importance may be indicated by the number of lines or dots and the lock information may be indicated by a box around a message number.