Abstract:
A power supply apparatus and method of supplying power to a mobile communication terminal are disclosed. When a battery&#39;s power for a communication module is used up, power from a battery for a personal digital assistant (PDA) module is supplied to the communication module to allow further use of the communication module. When the remaining capacity of the battery for the PDA module goes to a level of at which the PDA module is not operable, the power supply to the PDA module can be discontinued and power can be supplied to the communication module. Thus, call service can be continuously provided, even at lower battery power levels, to a user of the mobile communication terminal.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to a mobile communication terminal, and more particularly, to a power supply apparatus and method of supplying power to a mobile communication terminal.  
           [0003]    2. Background of the Related Art  
           [0004]    In general, a mobile communication terminal (referred to as ‘terminal’, hereinafter) includes a PDA (personal digital assistant) module for transmission or reception of e-mails or internet Web surfing and a communication module for voice communication. The PDA module and the communication module usually receive power through a common battery or a dual battery. The common battery supplies power to both the PDA and the communication module, while the dual battery supplies power to the PDA module and the communication module individually by using separate batteries.  
           [0005]    In the related art, when a common battery is used, the common battery use time is shortened due to the high power consumptions by the display unit, the short message services (SMS) or the call services of the terminal. When a dual battery is used and the battery power for the communication module is used up, the use time of the entire terminal is shortened and there is no way to extend the use time for the call service.  
           [0006]    The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.  
         SUMMARY OF THE INVENTION  
         [0007]    An object of the invention is to provide a power supply apparatus and method of supplying power to a mobile communication terminal that is capable of extending a call service use time of a terminal having a common battery.  
           [0008]    Another object of the present invention is to provide a power supply apparatus and method of a mobile communication terminal that is capable of extending a call service use time of a terminal having a dual battery.  
           [0009]    To achieve at least the above objects in whole or in parts, there is provided a power supply apparatus of a mobile communication terminal including: a common battery for supplying a power to a PDA module and a communication module, a relay switch connected between the common battery and the PDA module, and a level sensing unit for turning off the relay switch if a remaining capacity of the common battery is below a predetermined level.  
           [0010]    To achieve at least these advantages in whole or in parts, there is further provided a power supply apparatus of a mobile communication terminal including: a first battery for supplying a power to a PDA module, a second battery for supplying a power to a communication module, a first relay switch connected between the first battery and the PDA module, a second relay switch connected between the first battery and the communication module, a first level sensing means for sensing the remaining capacity of the first battery and controlling the first relay switch, and a second level sensing means for sensing the remaining capacity of the second battery and controlling the second relay switch.  
           [0011]    To achieve at least these advantages in whole or in parts, there is further provided a power supply apparatus of a mobile communication terminal including: a first battery for supplying a power to a PDA module, a second battery for supplying a power to a communication module, a first relay switch connected between the first battery and the PDA module, a second relay switch connected between the first battery and the communications module, first and second level sensing units for sensing a remaining capacity of first and second batteries, and a controller for controlling operations of the first and second relay switches and the PDA module according to a remaining capacity of the first and second batteries.  
           [0012]    To achieve at least these advantages in whole or in parts, there is further provided a power supply method of a mobile communication terminal including supplying a power from a common battery to a PDA module and a communication module, sensing a remaining capacity of the common battery, and cutting off the power from the common battery to the PDA module if the sensed remaining capacity is below a predetermined level.  
           [0013]    To achieve at least these advantages in whole or in parts, there is further provided a power supply method of a mobile communication terminal including supplying power from a first battery to a PDA module, supplying power from a second battery to a communication module, detecting a remaining capacity of the first and second batteries, and controlling power from the first battery to the communication module and from the first battery to the PDA module.  
           [0014]    Also provided is a preferable method of controlling the power supply of a mobile communication terminal in accordance with the present invention which includes checking whether the remaining capacity of the second battery is below a second level, supplying a power from the first battery to the communication module if the remaining capacity of the second battery is below the second level, checking whether the remaining capacity of the first battery is below a first level, and cutting off a power supply from the first battery to the PDA module if the remaining capacity of the first battery is below a first level.  
           [0015]    Additionally, another preferable method of controlling the power supply of a mobile communication terminal in accordance with the present invention includes checking whether the remaining capacity of the second battery is below a second level, checking whether the remaining capacity of the first battery is above the first level if the remaining capacity of the second battery is below the second level, supplying a power of the first battery to the communication module if the remaining capacity of the first battery is above the first level, and cutting off power from the first battery to the PDA module if the remaining capacity of the first battery is below the first level.  
           [0016]    Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]    The invention will be described in detail with reference to the following drawings in which like reference numerals refer to like elements wherein:  
         [0018]    [0018]FIG. 1 is a schematic block diagram of a power supply apparatus of a mobile communication terminal having a common battery in accordance with a first embodiment of the present invention;  
         [0019]    [0019]FIG. 2 is a flow chart of a power supply operation of FIG. 1 in accordance with the first embodiment of the present invention;  
         [0020]    [0020]FIG. 3 is a schematic block diagram of a power supply apparatus of a mobile communication terminal having a dual battery in accordance with a second embodiment of the present invention;  
         [0021]    [0021]FIG. 4 is a flow chart of a power supply operation of FIG. 3 in accordance with the second embodiment of the present invention;  
         [0022]    [0022]FIG. 5 is a schematic block diagram of a power supply apparatus of a mobile communication terminal having a dual battery in accordance with a third embodiment of the present invention; and  
         [0023]    [0023]FIG. 6 is a flow chart of a power supply operation of FIG. 5 in accordance with the third embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0024]    The operation of the power supply apparatus of a mobile communication terminal in accordance with the first embodiment of the present invention constructed as described above will now be explained with reference to FIGS. 1 and 2.  
         [0025]    [0025]FIG. 1 is a schematic block diagram of a power supply apparatus of a mobile communication terminal having a common battery in accordance with a first embodiment of the present invention. As shown in FIG. 1, a power supply apparatus of a mobile communication terminal includes a battery  12  charged by a charging circuit  10  and commonly supplying power to both a PDA module  16  and a communication module  18 . Also illustrated in FIG. 1 is a relay switch  14  connected between the battery  12  and the PDA module  16 , and a level sensing unit  20  for sensing a remaining capacity of the battery  12  and controlling the relay switch  14 . D 1  and D 2  are reverse current preventing diodes.  
         [0026]    Generally, the battery  12  can be directly charged by the charging circuit  10  or can be charged through a separate charging device and mounted in the terminal. After the battery  12  is charged, when a user depresses a power supply key S 10 , the first relay switch  14  can be maintained in an ON state at an initial stage. Accordingly, the charging power of the battery  12  can also be supplied to the PDA module  16  through the diode D 1  and the relay switch  14 , and simultaneously, supplied to the communication module  18  through the diode D 2 .  
         [0027]    At this time, the level sensing unit  20  detects the remaining capacity of the battery  12  and checks whether the detected remaining capacity of the battery is below a predetermined level (steps S 11  and S 12 ). Next, if the detected battery capacity is below the predetermined level, the level sensing unit  20  turns off the relay switch  14  to cut off power from the battery to the PDA module  16  (step S 13 ). Accordingly, if the power of the battery  12  is supplied only to the communication module  18 , even if the remaining capacity of the battery  12  is short, the user can maximize the power supplied to the communication module  18  and thus extend the power to a call service.  
         [0028]    [0028]FIG. 3 is a schematic block diagram of a power supply apparatus of a mobile communication terminal having a dual battery in accordance with a second embodiment of the present invention. As shown in FIG. 3, a preferred power supply apparatus of a mobile communication terminal can include first and second batteries  22  and  24  for respectively supplying power to a PDA module  30  and a communication module  32 , a first relay switch  26  connected between the first battery  22  and the PDA module  26 , and a second relay switch  28  connected between the first battery  22  and the communication module  32 .  
         [0029]    In addition, the apparatus can also include a first level sensing unit  34  for sensing i a remaining capacity of the first battery  22  and controlling the first relay switch  26  and a second level sensing unit  36  for sensing a remaining capacity of the second battery  24  and controlling the second relay switch  28 . The first and second batteries  22  and  24  are usually batteries for a PDA module  30  and a communication module  32 , respectively, and D 3 -D 6  are preferably reverse current preventing diodes.  
         [0030]    The operation of the power supply apparatus of a mobile communication terminal in accordance with the second embodiment of the present invention would begin with the charging of the first and second batteries,  22 ,  24 . After the first battery  22  is charged by the charging circuit  20 , the charging is discontinued, and if the power in the first and second batteries is adequate, the first relay switch  26  can be turned on and the second relay switch  28  can be turned off so that the first battery can supply power to the PDA alone through the first switch  26  and the power of the second battery  24  can be supplied to the communication module  32  alone through the diode D 3  (step S 20 ).  
         [0031]    Next, the first and second level sensing units  34  and  36 , respectively, detect a remaining capacity of the first and second batteries  22  and  24  and determine how to control the first and second relay switches  26  and  28  depending on the remaining capacities of the batteries  24 ,  26  as detected. That is, the second level sensing unit  36  detects a remaining capacity of the second battery  24  and checks whether the detected remaining battery capacity is below a second level (steps S 21  and S 22 ). If the remaining capacity of the second battery  24  is above the second level, the second level sensing unit  36  keeps on performing the detecting operation. If, however, the remaining capacity of the second battery  24  is below the second level, the second level sensing unit  36  turns on the second relay switch  28  so that the power of the first battery  22  can be supplied to the communication module  32  through the diode D 4  (step S 25 ). At this time, the second level can be a power level at which the communication module  32  may not be stably operable.  
         [0032]    Accordingly, as the communication module  32  receives power from the first battery  22 , it can provide calling service to the user, and since the PDA module  30  also can continuously receive power from the first battery  22 , the user can smoothly perform transmission and reception of e-mail and Web surfing using both the PDA and communication modules  30 ,  32 . In this state, the first level sensing unit  34  continuously checks whether the remaining capacity of the first battery  22  is below the first level. If the remaining capacity of the first battery  22  is below the first level, the first level sensing unit  34  turns off the first relay switch  26  to cut off power from the first battery  22  to the PDA module  30 , so that the power of the first battery  22  is supplied only to the communication module  32 . The first level can be set as a power level at which the PDA module  30  may not be stably operable, or set as a power level at which the PDA module  30  is operable and the communication module  32  is stably operable for an arbitrary time. Preferably, the first level is higher than the second level.  
         [0033]    In summary, if the battery power for the communication module  32  is used up (i.e., the second battery  24 ), the power of the battery for the PDA module  30  (i.e., the first battery  22 ) can be shared with the communication module  32 . On the other hand, if the battery for the PDA module  30  is used up, the PDA module  30  can be turned off and power can be solely supplied to the communication module  32  to extend a user&#39;s available time of the call service.  
         [0034]    [0034]FIG. 5 is a schematic block diagram of a power supply apparatus of a mobile communication terminal having a dual battery in accordance with a third embodiment of the present invention. As shown in FIG. 5, a controller  38  is added to the power supply apparatus of a mobile communication terminal in accordance with the second embodiment of the present invention. The controller  38  can be used to receive a sensing level from the first and second level sensing units  34  and  36  and to control the operations of the first and second relay switches  26  and  28  and the operation of the PDA module  30 .  
         [0035]    As shown in FIG. 6, when the first and second batteries  22 ,  24  have been charged by the charging circuit  20 , the first and second batteries  22 ,  24  can be used as the power sources for the terminal. If each battery has an adequate amount of power, the first relay switch  26  is turned on and the second relay switch  28  is turned off. Accordingly, the power of the first battery  22  can be supplied to the PDA module  30  alone through the first switch  26  and the power of the second battery  24  can be supplied to the communication module  32  alone through the diode D 3 .  
         [0036]    At this time, the first and second level sensing units  34  and  36 , respectively, detect the remaining capacities of the first and second batteries  22  and  24  and supplies information on the detected capacities to the controller  38 . Then, the controller  38  can be used to control the operations of the first and second relay switches  26  and  28  and the PDA module  30  according to the remaining capacity of the first and second batteries  22  and  24 . The controller  38  can also be used to determine whether the remaining capacity of the second battery  24 , as provided by the second level sensing unit  36 , is below a second level (steps S 31  and S 32 ). In this respect, the second level is a power level at which the communication module  32  is not stably operable.  
         [0037]    If the remaining capacity of the second battery  24  is above the second level, the controller  38  can check whether the remaining capacity of the first battery  22  is above a first level (step S 33 ). If the remaining capacity of the first battery  22  is above the first level, the controller  38  turns on the second relay switch  28  to provide the power of the first battery  22  to the communication module  32 . In this respect, the first level can be set as a power level at which the PDA module  30  may not be stably operable, or set as a power level at which the PDA module  30  can be operable and the communication module  32  can be stably operable. Generally, the first level is higher than the second level.  
         [0038]    Accordingly, as the communication module  32  can receive power from the first battery  22  after exhausting the second battery  24 , it can provide call service to the user, and since the PDA module  30  also continuously receives power from the first battery  22 , the user can continue the use of both the communication and PDA modules  32 ,  30 .  
         [0039]    In addition to transferring all the power of the first battery  22  to the communication module  32 , the controller  38  can also be used to reduce the power consumption of the first battery  22 . This can be accomplished by supplying power from the first battery  22  to the PDA module  30  only when necessary, for example, when e-mail or Web surfing service is accessed. For example, when power is initiated from the first battery  22  to the communication module  32 , the controller  38  can check whether the PDA is currently being used (step S 35 ). If the PDA is currently used, the controller  38  can then turn on the PDA module  30  and the communication module  32  (steps S 36  and S 37 ). If, however, the PDA module is not used, the controller  38  can turn off the PDA module  30  and turn on only the communication module  32 , thereby reducing the power consumption of the first battery  22  (steps S 38  and S 39 ).  
         [0040]    Thereafter, if the remaining capacity of the first battery is below the first level, the controller  38  can turn off the first relay switch  26  to cut off power from the first battery  22  to the PDA module  30 , so that the PDA module  30  is turned off. As a matter of course, since the second relay switch  28  is maintained in the ON state, power can be continuously supplied from the first battery  22  to the communication module  32 , so that the user can continuously use the call service.  
         [0041]    Also, as a further way to minimize power consumption, power to a display of a terminal can be limited in a preferred embodiment by power being limited to only the communication module  32  and only a portion of the whole display. The display unit may also be dividedly constructed into sections as where only specific sections (i.e., relating to the communication module  32 ) are driven when a power is supplied to either or both of the PDA module  30  and the communication module  32 , so that the power consumption by the display can be minimized, for example, power can be supplied to only the communication module sections of the display when call service is accessed.  
         [0042]    The power supply apparatus of a mobile communication terminal of the present invention has many advantages. First, if the battery power for the communication module is used up, the power of the battery for the PDA module can be supplied to the communication module, thereby extending a use available time for the call service. In addition, if the remaining capacity of the battery supplying power to the PDA is below a predetermined level necessary to operate the PDA module, the power supply to the PDA module can be discontinued and the remaining power can be supplied only to the communication module, so that call service can be continuously provided to the user.  
         [0043]    The foregoing embodiments and advantages are merely exemplary and are not to be construed as limiting the present invention. The present teaching can be readily applied to other types of apparatuses. The description of the present invention is intended to be illustrative, and not to limit the scope of the claims. Many alternatives, modifications, and variations will be apparent to those skilled in the art.