Abstract:
Disclosed is a portable device which includes: a battery, a temperature determining unit which determines a temperature of the portable device, a temperature of the battery and a temperature of external air; a power unit which receives power from the battery and applies the power to the portable device; and a central processing unit which controls the power unit to cut off power to the portable device, based on at least one of the temperatures determined by the temperature determining unit, thereby preventing accidents when using the portable device.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority from Korean Patent Application No. 10-2008-0078549, filed on Aug. 11, 2008, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    Apparatuses and methods consistent with the present general inventive concept relate to a portable device and a control method thereof, and more particularly, to a portable device using a battery, which prevents an accident, and a control method thereof. 
         [0004]    2. Description of the Related Art 
         [0005]    Due to portability of a portable device, a power supply thereof is limited. Thus, the portable device is used with a chargeable battery to solve the problem of limited power supply. 
         [0006]    Meanwhile, the portable device tends to have numerous integrated circuits (ICs) therein as its performance and capabilities improve. In this case, the ICs may generate excessive heat while operating at high speeds. Thus, the prevention of an accident due to high temperatures is a concern regarding portable devices which employ batteries, such as a laptop computer. 
       SUMMARY OF THE INVENTION 
       [0007]    The present general inventive concept provides a portable device which prevents an accident such as a battery explosion, and a control method thereof. 
         [0008]    Additional features and utilities of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present general inventive concept. 
         [0009]    Embodiments of the present general inventive can be achieved by providing a portable device which receives power from a battery. The portable device may include a temperature determining unit which determines a temperature of the portable device, a temperature of the battery and a temperature of external air, a power unit which receives power from the battery and applies the power to the portable device, and a central processing unit which controls the power unit to cut off power to the portable device, based on at least one of the determined temperatures. 
         [0010]    The temperature determining unit may directly determine the temperature of the battery or indirectly determine the temperature of the battery received through a communication between the central processing unit and the battery. 
         [0011]    The central processing unit may control the power unit to cut off power supplied to the portable device if the temperature of the external air is greater than or equal to a preset temperature. 
         [0012]    The central processing unit may control the power unit to cut off power supplied to the portable device if the temperature of the portable device or the temperature of the battery is equal to or greater than a critical temperature. 
         [0013]    The central processing unit may control the power unit to cut off power supplied to the portable device if at least one of temperature changes in the portable device, the battery and the external air per unit time is greater than or equal to a preset reference value. 
         [0014]    The central processing unit may control the battery to stop being charged or discharged depending on at least one of the determined temperatures. 
         [0015]    Embodiments of the present general inventive concept can also be achieved by providing a system which has a battery and a portable device that may include a portable device which determines a temperature of the portable device, a temperature of the battery and a temperature of external air, and controls the battery to stop being charged or discharged depending on at least one of the determined temperatures; and a battery which supplies power to the portable device, and stops being charged or discharged according to a control of the portable device. 
         [0016]    The portable device may cut off power based on at least one of the determined temperatures. 
         [0017]    Embodiments of the present general inventive concept can also be achieved by providing a control method of a portable device which receives power from a battery that may include determining a temperature of the portable device, a temperature of the battery and a temperature of external air, and cutting off power to the portable device based on at least one of the determined temperatures. 
         [0018]    The determining of the temperature of the battery may include directly determining the temperature of the battery, or indirectly determining the temperature of the battery received through communication between a central processing unit and the battery. 
         [0019]    The power supplied to the portable device may be cut off if the temperature of the external air is greater than or equal to a preset temperature. 
         [0020]    The power supplied to the portable device may be cut off if the temperature of the portable device or the temperature of the battery is equal to or greater than a critical temperature. 
         [0021]    The power supplied to the portable device may be cut off if at least one of temperature changes in the portable device, the battery and the external air per unit time, is greater than or equal to a preset reference value. 
         [0022]    The method may further comprise controlling the battery to stop being charged or discharged depending on at least one of the determined temperatures. 
         [0023]    Embodiments of the present general inventive concept can also be achieved by a portable device which receives power from a battery that may include a temperature determining unit to determine a temperature thereof, a temperature of the battery, and a temperature of the surrounding environment, and a control system which controls receiving power from the battery based on at least one of the temperatures determined. 
         [0024]    The control system may include a power unit to receive power from the battery and to apply the power to the portable device, and a central processing unit. 
         [0025]    The central processing unit may control the power unit to cut off power supplied to the portable device if at least one of the temperature of the portable device, the temperature of the battery and the temperature of the surrounding environment is greater than or equal to a critical temperature. 
         [0026]    The central processing unit may control the power unit to cut off power supplied to the portable device if at least one of the temperature changes in the portable device, the battery, and the external air per unit time is greater than or equal to a preset reference value. 
         [0027]    Embodiments of the present general inventive concept can also be achieved by providing a computer-readable medium to contain computer-readable codes providing commands for computers to execute a process that may include determining a temperature of a portable device, a temperature of a battery of the portable device, and a temperature of external air; and cutting off power to the portable device based on at least one of the determined temperatures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0028]    The above and/or other aspects of the present general inventive concept will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
           [0029]      FIG. 1  is a control block diagram of a portable device and a battery according to an embodiment of the present general inventive concept; 
           [0030]      FIG. 2  is a control flowchart of a portable device according to an exemplary embodiment of the present general inventive concept; 
           [0031]      FIG. 3  is a control flowchart of a portable device according to another exemplary embodiment of the present general inventive concept; and 
           [0032]      FIG. 4  is a control flowchart of a portable device according to yet another exemplary embodiment of the present general inventive concept. 
       
    
    
     DETAILED DESCRIPTION 
       [0033]    Reference will now be made in detail to the embodiments of the present general inventive concept, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present general inventive concept by referring to the figures. 
         [0034]    Hereinafter, a portable device and a battery according to an embodiment of the present general inventive concept will be described in detail. 
         [0035]      FIG.1  is a control block diagram of the portable device and the battery according to an embodiment of the present general inventive concept. 
         [0036]    A portable device  100  refers to an electronic portable device such as a notebook computer, a laptop computer, a cellular phone, a personal digital assistant (PDA), a digital camera, a portable MP3 player, a portable DVD player, and the like. 
         [0037]    The portable device  100  may include a temperature determining unit  102 , a central processing unit  104 , and a power unit  106 . 
         [0038]    The temperature determining unit  102  determines a temperature of the portable device  100 , a temperature of the battery  200  and a temperature of external air. In this case, the temperature determining unit  102  may directly determine a temperature of the battery  200  or indirectly determine a temperature of the battery  200  by receiving the temperature of the battery  200  through communication with the battery  200 . 
         [0039]    If the temperature determining unit  102  directly determines a temperature of the battery  200 , it may read the temperature sensed by respective temperature sensors of the portable device  100  and the battery  200 . To this end, the portable device  100  may include a first temperature sensor  108  to sense its own temperature and a third temperature sensor  110  to sense a temperature of the external air. Moreover, the battery  200  may include a second temperature sensor  206  to sense its own temperature. 
         [0040]    Meanwhile, the third temperature sensor  110  may be attached to the outside of the portable device  100  to be exposed to air. 
         [0041]    In this case, the first, second and third temperature sensors  108 ,  206  and  110  may each include a thermistor which is a semiconductor element to measure a temperature corresponding to resistance. 
         [0042]    If the temperature determining unit  102  indirectly determines the temperature of the battery  200 , the portable device  100  may receive information about the temperature of the battery  200  through a system management bus (SMBus) communication with the battery  200 . Power control between the portable device  100  and the battery  200  is performed through a SMBus. Thus, the temperature determining unit  102  may receive information about the temperature of the battery  200  through a communication interface, such as a SMBus, instead of directly sensing the temperature of the battery  200  through the temperature sensor. However, since the SMBus is a two-line simple bus used for communicating with low speed devices on a mother board, there are limitations, such as communication speed, communication subject, etc. For example, due to limited communication speeds, the temperature of external air may reach a dangerous level before the information about the temperature of the battery  200  is received from the battery  200 . Thus, if the temperature determining unit  102  directly senses the temperature of the battery  200 , as opposed to indirectly sensing the temperature, the portable device  100  may be more stable against a dangerous situation. A dangerous situation may occur when there is an increased likelihood of an accident, such as a battery explosion, due to high temperatures. 
         [0043]    The central processing unit  104  controls the portable device  100  and the battery  200  according to the temperatures determined by the temperature determining unit  102 , i.e., according to the temperature of the portable device  100 , the temperature of the external air and the temperature of the battery  200 . 
         [0044]    More specifically, the central processing unit  104  may control the power unit  106  to cut off power to the portable device  100  if the determined temperature of the external air reaches a preset temperature. 
         [0045]    If the determined temperature of the external air reaches a preset temperature, the central processing unit  104  may also control the battery  200  to stop being charged or discharged. In this case, the central processing unit  104  outputs a charging suspension signal or a discharging suspension signal to a power circuit  202  of the battery  200 . 
         [0046]    The power unit  106  shuts down the portable device  100  by cutting off the power based on a control of the central processing unit  104 . 
         [0047]    A power supply source of the power unit  106  may include the battery  200 . The power unit  106  may control the power to the portable device  100  by receiving the power from the battery  200 . 
         [0048]    The battery  200  may supply power to the portable device  100 , and be attached to or detached from the portable device  100 . The battery  200  may include the power circuit  202  and a battery cell  204 . 
         [0049]    The power circuit  202  controls the battery cell  204  to stop being charged or discharged according to a control of the central processing unit  104 . More specifically, the power circuit  202  turns off a charging switch according to a charging suspension signal outputted from the central processing unit  104  of the portable device  100 . Similarly, the power circuit  202  turns off a discharging switch according to a discharging suspension signal outputted from the central processing unit  104  of the portable device  100 . 
         [0050]    The battery cell  204  stops being charged or discharged according to a control of the power circuit  202 . The battery cell  204  may include a common chargeable/dischargeable cell. For example, the battery cell  204  may include a nickel-cadmium battery, a lead storage battery, a nickel-hydrogen battery, a lithium-ion battery, a lithium polymer battery or a lithium metal battery, a zinc air battery, and the like. A single or a plurality of battery cells  204  may be used. The plurality of battery cells  204  may be connected in series or in parallel. 
         [0051]    Meanwhile, the battery  200  may include a second temperature sensor  206  to sense a temperature of the battery  200 , which is mentioned above. 
         [0052]    Hereinafter, a control method of the portable device  100  and the battery  200  will be described in detail. 
         [0053]      FIG. 2  is a control flowchart of the portable device  100  according to an exemplary embodiment of the present general inventive concept. 
         [0054]    The portable device  100  may be influenced by not only its own temperature and the temperature of the battery  200 , but also the temperature of external air. Thus, the portable device  100  according to the present exemplary embodiment of the present invention considers the temperature of external air. 
         [0055]    While the portable device  100  operates (operation S 201 ), it determines the temperature of external air (operation S 202 ). 
         [0056]    In this exemplary embodiment, the portable device  100  determines whether the temperature of the external air reaches a critical temperature (operation S 203 ). The critical temperature refers to a previously set temperature at which the portable device  100  enters a dangerous situation. The critical temperature of the portable device  100  may be set by a user or set as a default by a manufacturer. 
         [0057]    Further, the critical temperature may be set in consideration of factors which can affect the safety of the portable device  100  and the battery  200 . Such factors may include, but are not limited to, the specification and the environment of the portable device and the battery, and the like. 
         [0058]    For example, the temperature of the portable device  100  at a maximum load varies depending on storage capacity of the portable device  100 . As a result, each portable device  100  has a different critical temperature of external air at which it faces a dangerous situation. 
         [0059]    The critical temperature of external air at which the portable device  100  faces a dangerous situation may vary depending on the environment where the portable device  100  is being used. For example, when the portable device  100  or the battery  200  are negatively affected by electromagnetic energy, the critical temperature of the external air of the portable device  100  is lowered. In other words, the critical temperature may vary as a result of other factors such as the environment where the portable device  100  is being used. 
         [0060]    Thus, the portable devices  100  can set different critical temperatures of the external air based on a variety of factors. When the temperature of the external air reaches the critical temperature, the portable device  100  controls itself and the battery  200  regardless of the temperature of the portable device  100  and the temperature of the battery  200 . 
         [0061]    If the temperature of the external air does not reach the critical temperature, the portable device  100  goes back to the operation S 202  and continues to monitor the temperature of the external air. 
         [0062]    If it is determined that the temperature of the external air reaches the critical temperature (operation S 203 ), the portable device  100  shuts down the system by cutting off power to the portable device  100  (operation S 204 ) in order to prevent a dangerous situation due to high temperatures. The portable device  100  similarly controls the battery  200  to stop being charged or discharged (operation S 205 ). 
         [0063]    According to embodiments of the present general inventive concept, the portable device  100  can control itself or the battery  200  selectively. That is, either the control to cut-off the power to the portable device  100  or the control to suspend the discharge of the battery  200  may be performed, or the foregoing two operations may be performed at the same time. If the portable device  100  and the battery  200  are controlled at the same time, accidents that occur while the portable device  100  is using the battery  200  may be prevented more effectively. 
         [0064]    While the temperatures of the portable device  100  and the battery  200  are stable at safe temperatures, the temperature of the external air may drastically rise. According to the previous exemplary embodiment of the present general inventive concept, accidents due to the temperature of the external air may be prevented regardless of the status of the portable device  100  and the battery  200 . 
         [0065]      FIG. 3  is a control flowchart of a portable device according to another exemplary embodiment of the present general inventive concept. 
         [0066]    Synergy among the portable device  100 , the battery  200  and external air may accelerate a dangerous situation. For example, if the temperature of the portable device  100  and the temperature of external air rise at the same time, the synergy therebetween may accelerate a dangerous situation. Accordingly, the control method in  FIG. 3  considers the temperature of the battery  200 , the temperature of the portable device  100 , and the temperature of external air at the same time in controlling the portable device  100  and the battery  200 . 
         [0067]    While the portable device  100  operates (operation S 301 ), a temperature determining unit  102  determines a temperature of the portable device  100  and a temperature of external air (operation S 302 ). At the same time, the temperature determining unit  102  determines a temperature of the battery  200  (operation S 303 ). 
         [0068]    The portable device  100  compares the actual temperatures determined by the temperature determining unit  102  with critical temperatures (operation S 304 ). 
         [0069]    The critical temperature may be set based on experiments that take into consideration the correlation among the portable device  100 , the battery  200  and the external air. For example, a temperature of the portable device  100  and the battery  200  that, when combined, increase the likelihood of a dangerous situation with regard to the temperature of the external air, this combined temperature may be set as a critical temperature. Similarly, a temperature of the battery  200  and the external air that, when combined increase the likelihood of a dangerous situation with regard to the temperature of the portable device  100 , this combined temperature may be set as a critical temperature. Additionally, a temperature of the portable device  100  and the external air that, when combined, increase the likelihood of a dangerous situation with regard to the temperature of the battery  200 , this combined temperature may be set as a critical temperature. 
         [0070]    A critical temperature may be set based on the combination of two of the temperature of the portable device  100 , the temperature of the battery  200  and the temperature of the external air, if a combined temperature that is greater than or equal to the critical temperature increases the potential for a dangerous situation to occur with respect to temperature. 
         [0071]    The portable device  100  determines whether the determined temperature reaches the critical temperature (operation S 305 ). That is, if the determined temperature reaches one of the critical temperatures set according to various criteria as described above, the portable device  100  determines that it faces a dangerous situation. 
         [0072]    If the determined temperature is equal to or greater than the critical temperature, the portable device  100  shuts down the system by cutting off power to the portable device  100  (operation S 306 ). The portable device  100  controls the battery  200  to stop being charged or discharged (operation S 307 ). In this case, the portable device  100  or the battery  200  may be controlled selectively as shown in  FIG. 2 . 
         [0073]    If the determined temperature is less than the critical temperature, the portable device  100  goes back to the operation S 302  and continues to monitor the temperature of the battery  200 , the temperature of the portable device  100  and the temperature of the external air. 
         [0074]    Even if the respective temperatures of the external air, the portable device  100  and the battery  200  are not so high as to make a dangerous situation more likely to occur, they may face a dangerous situation due to synergy. According to the present exemplary embodiment of the present general inventive concept, a dangerous situation due to the synergy among the portable device  100 , the battery  200  and the external air may be prevented. 
         [0075]      FIG. 4  is a control flowchart of a portable device according to yet another exemplary embodiment of the present general inventive concept. 
         [0076]    If a portable device  100  is used in abnormal environment, i.e., if it does not operate in a normal environment, accidents may occur. According to experiments, the temperature of the portable device  100  (e.g., a notebook computer) and the battery  200  rises by 30 degrees or more when used in closed space (for example, on bedding, an electric blanket, a bag, etc.) than in normal environment. A normal environment, in the case of a notebook computer, may include, but is not limited to, a desk, a table, etc. In this case, it takes considerable time to lower the temperature to a safe level, and the portable device  100  may face a dangerous situation. 
         [0077]    To prevent such a dangerous situation, the portable device  100  and the battery  200 , according to the present exemplary embodiment of the present general inventive concept, are controlled depending on changes in the temperature of the portable device  100 , the temperature of the battery  200  and the temperature of the external air. That is, if the changes in the temperature of the portable device  100 , the temperature of the battery  200  and the temperature of the external air are drastic compared with a preset reference value, it is determined that the portable device  100  or the battery  200  operates in abnormal environment. 
         [0078]    While the portable device  100  operates (operation S 401 ), it determines the changes in the temperature of the portable device  100  per unit time (operation S 402 ) and measures the changes in the temperature of the battery  200  per unit time (operation S 403 ). At the same time, the portable device  100  measures the changes in the temperature of the external air per unit time (operation S 404 ). 
         [0079]    The portable device  100  determines whether it faces a dangerous situation (operation S 405 ) according to the measured temperature changes. More specifically, the portable device  100  compares the measured changes in the temperature with the preset reference value, and determines whether the portable device  100 , the battery  200  and the external air exhibit temperature change that suggests an abnormal environment or situation. For example, if at least one among the temperatures of the external air, the portable device  100  and the battery  200  changes drastically, it may be determined that the portable device  100  is in an abnormal situation. That is, if at least one of the temperature changes of the portable device  100 , the battery  200  and the external air per unit time is equal to or greater than the preset reference value, it is determined that the portable device  100  operates in abnormal environment. 
         [0080]    If it is determined that the portable device  100  operates in the abnormal environment and faces a dangerous situation (operation S 406 ), the portable device  100  shuts down the system by cutting off power to the portable device  100  (operation S 407 ). The portable device  100  controls the battery  200  to stop being discharged (operation S 408 ). In this case also, the portable device  100  or the battery  200  may be controlled selectively. 
         [0081]    If it is determined that the portable device  100  does not face a dangerous situation, the portable device  100  goes back to the operation S 402  and continues to monitor the changes in the temperature of the portable device  100 , the temperature of the battery  200  and the temperature of the external air. 
         [0082]    According to the present general inventive concept, a dangerous situation due to various factors regarding a portable device using a battery may be prevented. 
         [0083]    The present general inventive concept can also be embodied as computer-readable codes on a computer-readable medium. The computer-readable medium can include a computer-readable recording medium and a computer-readable transmission medium. The computer-readable recording medium is any data storage device that can store data as a program which can be thereafter read by a computer system. Examples of the computer-readable recording medium include read-only memory (ROM), random-access memory (RAM), CD-ROMs, DVDs, Blu-Ray discs, magnetic tapes, floppy disks, optical data storage devices, and the like. The computer-readable recording medium can also be distributed over network coupled computer systems so that the computer-readable code is stored and executed in a distributed fashion. The computer-readable transmission medium can transmit carrier waves or signals (e.g., wired or wireless data transmission through the Internet). Also, functional programs, codes, and code segments to accomplish the present general inventive concept can be easily construed by programmers skilled in the art to which the present general inventive concept pertains. 
         [0084]    Although a few exemplary embodiments of the present general inventive concept have been shown and described, it will be appreciated by those skilled in the art that changes may be made in these exemplary embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.