Abstract:
An exemplary method for conserving power of a portable communication device includes: supplying voltage by a power supply; distributing voltages to other units of the portable communication device including a communication unit and a backlight unit; the portable communication device entering a normal mode after being powered by one of the voltages; generating digital voltage signals corresponding to the voltage supplied by the power supply; detecting a voltage of the digital voltage signals to obtain a detected voltage; comparing the detected voltage with a predetermined value; and if the detected voltage is equal to or less than the predetermined value, changing from the normal mode to a power conserving mode, and stopping distribution of the voltages to at least one of the communication unit and the backlight unit. Thereby, an operational time of other units of the portable communication device can be prolonged.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application is related to a commonly-assigned pending application filed concurrently herewith and also entitled “PORTABLE COMMUNICATION DEVICE AND METHOD FOR CONSERVING POWER”. Disclosure of the above identified application is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to portable communication devices and methods for conserving power of portable communication devices, and especially to a portable communication device and a method involving disabling of a unit of the portable communication device and thereby prolonging an operational time of other units of the portable communication device. 
         [0004]    2. Description of Related Art 
         [0005]    In the so-called “information age”, portable communication devices have become more and more important in people&#39;s lives. Portable communication devices include mobile phones, personal digital assistants (PDAs), and other similar devices. 
         [0006]    A typical portable communication device is supplied with voltage by a battery. Because the capacity of the battery is limited, when the voltage of the battery is below a certain value, the portable communication device becomes unusable. 
         [0007]    A common type of personal digital assistant (PDA) available in the market includes a communication unit. The communication unit can be disabled by a user independently of other functional units of the PDA. Thus, an operational time of the other functional units of the PDA can be prolonged. In detail, the PDA has a so-called flight mode. If the user selects the flight mode, the PDA restarts and disables the communication unit. After the communication unit of the PDA is disabled, the PDA can still be used to perform other functions, such as searching desired contact information in an address list, playing games, and so on. However, the communication unit needs to be disabled manually. The user may disable the communication unit only after the voltage of the battery has dropped below a certain critical threshold value. 
         [0008]    Therefore, a heretofore unaddressed need exists in the industry to overcome the aforementioned deficiencies and inadequacies. 
       SUMMARY OF THE INVENTION 
       [0009]    A portable communication device and a method for conserving power of a portable communication device are provided. The portable communication device can automatically stop supplying voltage to a communication unit thereof, when the voltage of the portable communication device is equal to or less than a predetermined value, thereby prolonging an operational time of the portable communication device. 
         [0010]    The portable communication device includes a power supply, a power management unit, an analog-to-digital converter and a central processing unit. The power supply supplies voltage to the power management unit and the analog-to-digital converter. The power management unit distributes one or more corresponding voltages to other units of the portable communication device. The analog-to-digital converter generates digital voltage signals corresponding to the voltage supplied by the power supply. The central processing unit includes a controlling module and a detection module. The controlling module signals the portable communication device to enter a normal mode after being powered by a voltage of the central processing unit. The detection module receives the digital voltage signals from the analog-to-digital converter, detects a voltage of the digital voltage signals to obtain a detected voltage, and compares the detected voltage with a predetermined value. If the detected voltage is equal to or less than the predetermined value and a current mode of the portable communication device is the normal mode, the controlling module signal the portable communication device to change from the normal mode to a power conserving mode, and when the portable communication device changes from the normal mode to the power conserving mode, the controlling module signals the power management unit to stop distributing voltage to at least one of the other units of the portable communication device selected from the group consisting of a communication unit and a backlight unit. 
         [0011]    Other systems, methods, features, and advantages will be or become apparent to one with skill in the art upon examination of the following drawings and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present invention, and be protected by the accompanying claims. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a front view of a mobile phone in accordance with an exemplary embodiment of the present invention. 
           [0013]      FIG. 2  is a block diagram of hardware infrastructure of the mobile phone of  FIG. 1 . 
           [0014]      FIG. 3  is a flowchart of an exemplary method for conserving power of the mobile phone of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0015]    The present features and functions involving conserving power can be incorporated in a portable communication device such as a mobile phone or a personal digital assistant (PDA). The following detailed description of exemplary and preferred embodiments is made with reference to the attached drawings. 
         [0016]      FIG. 1  is a front view of a mobile phone  10  in accordance with an exemplary embodiment of the present invention. The mobile phone  10  includes a display panel  11  and a keypad  12 . The display panel  11  is configured for displaying information of the mobile phone  10 , such as incoming calls, text messages, an address list, and so on. The keypad  12  includes a plurality of function keys and alphanumeric keys for users to enter operational instructions or other information. 
         [0017]      FIG. 2  is a block diagram of hardware infrastructure of the mobile phone  10 . In this aspect, the mobile phone  10  includes a power supply  13 , a power management unit  14 , a central processing unit  15 , a display unit  16 , a backlight unit  17 , a communication unit  18 , a command input unit  19 , a storage unit  20 , a vibration unit  21 , and a ring unit  22 . 
         [0018]    The power supply  13  may be a nickel-cadmium battery, a lithium-ion battery, or another suitable kind of secondary cell. The power supply  13  supplies voltage to the power management unit  14 . The power management unit  14  receives the voltage from the power supply  13 , and distributes corresponding voltages to various units of the mobile phone  10 . The units include the central processing unit  15 , the display unit  16 , the backlight unit  17 , the communication unit  18 , the command input unit  19 , the storage unit  20 , the vibration unit  21 , and the ring unit  22 . 
         [0019]    The display unit  16  is configured for displaying information of the mobile phone  10  via the display panel  11 . The information may include incoming calls, text messages, an address list, and so on. The backlight unit  17  is configured for illuminating the display panel  11 . After the operational instructions are input on the command input unit  19  by the user, the command input unit  19  can process the operational instructions accordingly. In particular, the command input unit  19  is configured for generating corresponding command instructions, and sends the command instructions to the central processing unit  15 . 
         [0020]    The communication unit  18  is configured for performing communication functions of the mobile phone  10 . That is, the communication unit  18  receives and/or transmits communication signals via wireless communication means, and as a result the mobile phone  10  is able to communicate with other communication devices (not shown). 
         [0021]    After the mobile phone  10  receives an incoming call or a text message, the central processing unit  15  signals the vibration unit  21  and/or the ring unit  22  to vibrate and/or ring, so as to alert the user. 
         [0022]    The storage unit  20  stores the address list, the text messages, and so on. Modes of the mobile phone  10  include a normal mode and a power conserving mode. In the normal mode, the mobile phone  10  can perform all its normal functions. The normal functions include receiving incoming calls, dialing outgoing telephone number, searching contact information, voice dialing or voice alerting, and so on. In the power conserving mode, the central processing unit  15  signals the power management unit  14  to stop distributing voltage to the communication unit  18  and/or the backlight unit  17 . Thereby, the mobile phone  10  cannot perform the function of receiving incoming calls or dialing the outgoing telephone number, and/or cannot perform the function of the display unit  16  being illuminated by the backlight unit  17 . 
         [0023]    The mobile phone  10  further includes an analog-to-digital converter  23 . After the mobile phone  10  is powered on, the power supply  13  supplies voltage to the analog-to-digital converter  23 . The analog-to-digital converter  23  generates digital voltage signals corresponding to the voltage, and sends the digital voltage signals to the central processing unit  15 . 
         [0024]    The central processing unit  15  includes a controlling module  151  and a detection module  152 . The controlling module  151  signals the mobile phone  10  to enter the normal mode after being powered by a voltage of the central processing unit  15 . 
         [0025]    The detection module  152  receives the digital voltage signals from the analog-to-digital converter  23 , detects a voltage of the digital voltage signals to obtain a detected voltage, and compares the detected voltage with a predetermined value. The predetermined value is a threshold amount of remaining voltage of the power supply  13 . When the detected voltage is less than the predetermined value, this means the remaining voltage of the power supply  13  is low. Accordingly, usage of the mobile phone  10  should be limited. For example, such usage is restricted to performing only certain functions, such as searching desired contact information in the address list if necessary. Thus, the detection module  152  conveys the result of the comparison of the detected voltage with the predetermined value to the controlling module  151 . At this time, the controlling module  151  detects a current mode of the mobile phone  10 . 
         [0026]    If the detected voltage is equal to or less than the predetermined value, and the mobile phone  10  is in the power conserving mode, the controlling module  151  does not signal the mobile phone  10  to change the current mode. However, if the mobile phone  10  is in the normal mode, the controlling module  151  signals the mobile phone  10  to change from the normal mode to the power conserving mode, and then signals the power management unit  14  to stop distributing voltage to the backlight unit  17  and/or the communication unit  18 . 
         [0027]    If the detected voltage is greater than the predetermined value, and the mobile phone  10  is in the normal mode, the controlling module  151  does not signal the mobile phone  10  to change the current mode. However, if the mobile phone  10  is in the power conserving mode, the controlling module  151  signals the power management unit  14  to resume distributing voltage to the backlight unit  17  and/or the communication unit  18 , and then signals the mobile phone  10  to change from the power conserving mode to the normal mode. 
         [0028]      FIG. 3  is a flowchart of an exemplary method for conserving power of the mobile phone  10 . In step S 30 , after the mobile phone  10  is powered on, the power supply  13  supplies voltage to the power management unit  14  and the analog-to-digital converter  23 . 
         [0029]    In step S 31 , the power management unit  14  receives the voltage from the power supply  13 , and distributes corresponding voltages to various units of the mobile phone  10 . 
         [0030]    In step S 32 , the controlling module  151  signals the mobile phone  10  to enter the normal mode after being powered by the voltage of the central processing unit  15 . 
         [0031]    In step S 33 , the analog-to-digital converter  23  generates digital voltage signals corresponding to the voltage supplied by the power supply  13 . 
         [0032]    In step S 34 , the detection module  152  receives the digital voltage signals, and detects a voltage of the digital voltage signals to obtain a detected voltage. 
         [0033]    In step S 35 , the detection module  152  determines whether the detected voltage is equal to or less than the predetermined value. 
         [0034]    If in step S 35  the detected voltage is equal to or less than the predetermined value, then in step S 36 , the controlling module  151  detects a current mode of the mobile phone  10 . 
         [0035]    If the mobile phone  10  is in the power conserving mode, the controlling module  151  does not signal the mobile phone  10  to change the current mode, and the procedure goes back to step S 34 . If the mobile phone  10  is in the normal mode, in step S 37 , the controlling module  151  signals mobile phone  10  to change from the normal mode to the power conserving mode, whereupon the procedure goes to step S 38 . 
         [0036]    In step S 38 , the controlling module  151  signals the power management unit  14  to stop distributing voltage to the backlight unit  17  and/or the communication unit  18 , whereupon the procedure goes back to step S 34 . 
         [0037]    If in step S 35  the detected voltage is greater than the predetermined value, then in step S 39 , the controlling module  151  detects a current mode of the mobile phone  10 . 
         [0038]    If the mobile phone  10  is in the normal mode, the controlling module  151  does not signal the mobile phone  10  to change the current mode, and the procedure goes back to step S 34 . If the mobile phone  10  is in the power conserving mode, in step S 40 , the controlling module  151  signals the power management unit  14  to resume distributing voltage to the backlight unit  17  and/or the communication unit  18 , whereupon the procedure goes to step S 41 . 
         [0039]    In step S 41 , the controlling module  151  signals the mobile phone  10  to change from the power conserving mode to the normal mode, whereupon the procedure goes back to step S 34 . Steps S 34  to S 41  are then performed iteratively if and as necessary until the mobile phone  10  is powered off. 
         [0040]    It is understood that the invention may be embodied in various other forms without departing from the spirit thereof. Thus, the present examples and embodiments are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given above.