Abstract:
A temperature control system of a mobile device is provided. The system includes a memory for storing a set temperature value and a release temperature value, a temperature sensor for sensing an internal temperature of the mobile device; at least one module that emits heat, and a controller. The controller compares the output of the temperature sensor with the set temperature value in a normal mode in order to determine whether the mobile device is overheated, and controls, if the mobile device is overheated, the at least one module to operate in a heat generation suppressing mode, compares the output of the temperature sensor with the release temperature value in the heat generation suppressing mode in order to determine whether to release the heat generation suppressing mode, and executes the normal mode if the heat generation suppressing mode is released according to the comparison result.

Description:
PRIORITY 
       [0001]    This is a continuation application of a prior U.S. patent application assigned Ser. No. 13/658,258 filed on Oct. 23, 2012, which issued as U.S. Pat. No. 9,232,135 on Jan. 5, 2016, and which claims the benefit under 35 U.S.C. §119(a) of a Korean patent application filed on Nov. 10, 2011 in the Korean Intellectual Property Office and assigned Serial No. 10-2011-0116774, the entire disclosures of which are each hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention: 
         [0003]    The present invention relates to a system and method for controlling the operations of a mobile device. More particularly, the present invention relates to a system and method for controlling the operations of a mobile device according to its internal temperature. 
         [0004]    2. Description of the Related Art: 
         [0005]    Mobile devices have been developed to simultaneously process a variety of functions, such as communication, multimedia, and the like. Mobile devices are getting thinner to enhance portability. However, thinner mobile devices have difficulty achieving efficient heat dissipation. Despite these difficulties that arise as mobile devices are made thinner, they are nonetheless required to execute an increasing variety of functions. For example, mobile devices may be developed with an increased number of processors, with an increased maximum clock speed, a larger Liquid Crystal Display (LCD) screen for improved brightness, a large capacity battery, a high resolution camera module, and the like. However, such increased functionality also causes undesirable heat generation in the mobile device. 
         [0006]    Attenuation of heat generated from parts in a mobile device so as to cause the parts to remain under their maximum operating temperatures has been difficult because the mobile device cannot be turned off. Therefore, as the modules operate in the mobile device, heat is generated that increases the temperature therein. Although conventional systems control the clock speed using a temperature sensor in the processor, they cannot prevent the mobile device from overheating while in operation. 
         [0007]    Therefore, a need exists for a system and method for attenuating the generation of heat from parts in a mobile device so as to cause the parts to remain under their maximum operating temperatures without the need to turn off the mobile device. 
         [0008]    The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present invention. 
       SUMMARY OF THE INVENTION 
       [0009]    Aspects of the present invention are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present invention is to provide a system and method that may detect a temperature inside a mobile device and control operations of at least one module that generates heat, thereby preventing the mobile device from overheating. 
         [0010]    Another aspect of the present invention is to provide a technology that arranges a temperature sensor near a component that generates heat in the mobile device, detects the generation of heat with a processor, and controls the operations of a corresponding component, thereby preventing the temperature in the mobile device from rising. 
         [0011]    In accordance with an aspect of the present invention, a temperature control system of a mobile device is provided. The system includes a memory for storing a set temperature value and a release temperature value, a temperature sensor for sensing an internal temperature of the mobile device, at least one module that emits heat, and a controller. The controller compares the output of the temperature sensor with the set temperature value in a normal mode in order to determine whether the mobile device is overheated, and controls, if the mobile device is overheated, the at least one module to operate in a heat generation suppressing mode, compares the output of the temperature sensor with the release temperature value in the heat generation suppressing mode in order to determine whether to release the heat generation suppressing mode, and executes the normal mode if the heat suppressing mode is released according to the comparison result. 
         [0012]    In accordance with another aspect of the present invention, a method for controlling temperature in a mobile device is provided. The method includes a memory for storing a set temperature value and a release temperature value, a temperature sensor for sensing an internal temperature of the mobile device, and at least one module that emits heat. The method includes detecting, by the temperature sensor, an internal temperature of the mobile device in a normal mode, comparing the detected temperature of the temperature sensor with the set temperature value to determine whether the mobile device is overheated, controlling, if the mobile device is overheated, the at least one module to operate in a heat generation suppressing mode, comparing the output of the temperature sensor with the release temperature value in the heat generation suppressing mode in order to determine whether to release the heat generation suppressing mode, and executing the normal mode if the heat generation suppressing mode is released according to the comparison result. 
         [0013]    In accordance with another aspect of the present invention, a system for controlling temperature in a mobile device is provided. The system includes a memory for storing a set temperature value and a release temperature value, at least one module that emits heat, at least one temperature sensor installed near the at least one module, and a controller. The controller compares an output of the at least one temperature sensor with the set temperature value in a normal mode in order to determine whether the at least one module is overheated and controls a corresponding at least one module that are overheated to operate in a heat generation suppressing mode, compares the output of the at least one temperature sensor for the at least one module operating in the heat generation suppressing mode with the release temperature value in order to determine whether to release the heat generation suppressing mode, and controls, if the heat generation suppressing mode of the corresponding at least one module is released according to the comparison result, the corresponding at least one module to operate in a normal mode. 
         [0014]    In accordance with another aspect of the present invention, a method for controlling temperature in a mobile device is provided. The method includes a memory for storing a set temperature value and a release temperature value, at least one module that emits heat, and at least one temperature sensor installed near the at least one module. The method includes comparing an output of the at least one temperature sensors with the set temperature value to determine whether the mobile device is overheated in a normal mode, controlling, if it is determined that the mobile device is overheated, the at least one module to operate in a heat generation suppressing mode, comparing the output of the at least one temperature sensor of the at least one module operating in the heat generation suppressing mode with the release temperature value in order to determine whether to release the heat generation suppressing mode of the at least one module, and operating, if the heat generation suppressing mode of the module is released according to the comparison result, the at least one module in a normal mode. 
         [0015]    Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0016]    The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings, in which: 
           [0017]      FIG. 1  illustrates a schematic block diagram of a mobile device according to an exemplary embodiment of the present invention; 
           [0018]      FIG. 2  illustrates a flowchart that describes a method for controlling temperature in a mobile device according to an exemplary embodiment of the present invention; 
           [0019]      FIG. 3  illustrates a flowchart that describes a method for analyzing an internal temperature of the mobile device and determining whether a heat generation suppressing mode is executed according to an exemplary embodiment of the present invention; 
           [0020]      FIG. 4  illustrates a flowchart that describes a method for selectively controlling modules as heat generation sources when an internal temperature of the mobile device increases and decreasing the internal temperature according to an exemplary embodiment of the present invention; and 
           [0021]      FIG. 5  illustrates a schematic block diagram of a mobile device according to an exemplary embodiment of the present invention. 
       
    
    
       [0022]    Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures. 
       DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS 
       [0023]    The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions may be omitted for clarity and conciseness. 
         [0024]    The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention is provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. 
         [0025]    It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces. 
         [0026]    By the term “substantially” it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide. 
         [0027]    Although the following exemplary embodiments of the present invention describe the surface temperature of a mobile device, the conversion temperature of a sensor, an overheating setting time period, and the like, it should be understood that the present invention is not limited thereto. 
         [0028]    As will be described in more detail below, an exemplary mobile device may include a built-in temperature sensor that detects an internal temperature in real time. An Intelligent Overheating Protection Controller (IOPC) controls modules of the mobile device, as causes of heat generation in the mobile device via a temperature detected by the temperature sensor, thereby preventing the mobile device from overheating. The IOPC may be included in a controller of the mobile device, or separated therefrom. In the following description, it is assumed that the controller of the mobile device serves to perform the functions of the IOPC. Various causes of heat generation in mobile devices may occur, for example, cases in which the display unit, charger, camera module, and/or controller are overloaded. The controller controls the operations of the respective modules, such as the processor, a Liquid Crystal display (LCD), a charger, a camera module, and the like, so as not to exceed a preset temperature based on a temperature detected by the temperature sensor. 
         [0029]    Examples of causes for heat generation in a mobile device may include cases in which the processor is too overloaded to execute applications, the charger module performs a charging operation with a large amount of current, the camera module takes a video, the display unit displays a large amount of data during execution of a game application, and the like. Heat energy generated in the mobile device accumulates and causes an increase in temperature on the outer surface of the mobile device, which deteriorates the performance of the mobile device. In order to prevent this, the system determines the relationship between the temperature on an outer surface of the mobile device with a temperature sensor (e.g., a thermistor). The analyzed temperatures detected by the temperature sensor are used in order to maintain an outer surface temperature, Tw, to control the modules which generate heat, thereby preventing low temperature burn. 
         [0030]    For example, a surface temperature Tw may be set to prevent a low temperature burn, and that corresponding temperature value is empirically acquired by a thermistor. When the mobile device is operated, the temperature sensor detects the internal temperature of the mobile device. The controller determines whether the temperature detected by the temperature sensor exceeds the empirically acquired temperature value. If the controller ascertains that the internal temperature increases, it controls the operations of the modules that generate heat in the mobile device. Examples of modules that generate heat include a controller, a display unit, a camera module, a charger, and the like. Although exemplary embodiments of the present invention may describe that the controller controls the heat generating modules listed above, it needs to be understood that the invention may also control other modules that generate heat in a mobile device. 
         [0031]    If the controller ascertains that the internal temperature of the mobile device has increased, it may control the heat generating modules listed above. For example, the controller may control the maximum brightness (contrast) of the display unit (e.g., LCD) (which refers to a level of brightness that may maintain a temperature equal to or less than a surface temperature Tw on the front side of the mobile device), and reduce the transfer period of screen data to the display unit. The controller may reduce the charging current of the charger (which refers to an amount of charging current that can maintain a temperature equal to or less than a surface temperature Tw on the outside of the mobile device). For example, if the surface temperature Tw of the mobile device is equal to or greater than 45° C. (corresponding to a conversion temperature of a thermistor set to 55° C.) for over 30 minutes, the controller may reduce the charging current. If the charge in the battery is reduced to equal to or less than the lowest remaining amount of battery (e.g., 20%) with which the mobile device can be operated, the controller may increase the charging current. Thereafter, if the charge in the battery increases over the lowest remaining amount of battery (e.g., 25%) with which the mobile device can be operated, the controller controls the charging current of the battery again. During the process, the temperature, time, and the battery charging amount, may be set to proper values, which are determined according to an experiment or a user request. The frame rate or the resolution of the camera may also be limited so that the outer surface of the mobile device where the camera is located can maintain a temperature equal to or less than a surface temperature Tw. Moreover, the maximum processor clock speed of the controller may be limited so that the front and back sides of the mobile device where the processor is located can maintain a temperature equal to or less than a surface temperature Tw. Based on the foregoing, the appropriate levels for limiting heat generating modules can be empirically set. 
         [0032]      FIG. 1  illustrates a schematic block diagram according to an exemplary embodiment of the present invention. 
         [0033]    Referring to  FIG. 1 , a communication unit  120  communicates with external systems or base stations in wireless mode. The communication unit  120  may include a transmitter and a receiver. The transmitter up-converts the frequency of signals to be transmitted and amplifies the power of the signals. The receiver low-noise amplifies received signals, and down-converts the frequency of the received signals to a base band. The communication unit  120  may include a modulator for modulating signals to be transmitted and transferring them to the transmitter, and a demodulator for demodulating signals received via the receiver. The modulator and demodulator may employ Long Term Evolution (LTE), Wideband Code Division Multiple Access (WCDMA), Global System for Mobile (GSM), Wi-Fi, Wireless Broadband (Wi-Bro), Near Field Communication (NFC), Bluetooth, and the like, according to different communication protocols. 
         [0034]    A controller  100  may control operations of the mobile device. The controller  100  may perform a temperature control function according to an exemplary embodiment of the present invention. 
         [0035]    A memory  110  may include a program storage memory and a data storage memory. The program storage memory may store an Operating System (OS) of the mobile device and application programs. The data storage memory may store tables related to the operations of the mobile device and data created when the application programs are executed. The memory  110  may store a table for setting temperature values and/or the corresponding temperature retention times to determine whether the mobile device is overheated. 
         [0036]    A temperature sensor  130  may detect an internal temperature of the mobile device and transfer it to the controller  100 . The temperature sensor  130  may be implemented with a thermistor. The temperature sensor  130  may be installed at a location where the greatest amount of heat is generated or expected to be generated in the mobile device, and the location may be empirically determined. The temperature sensor  130  may be installed near the controller  100 . 
         [0037]    A camera  140  may acquire video data at a preset frame rate and with a preset resolution, in a camera operation mode, under the control of the controller  100 . For example, the camera  140  may acquire a video at 30 frames per sec (30 fps) with a resolution of 1080 pixels in a normal mode, and a video at 15 fps 720 pixels in a heat generation suppressing mode. 
         [0038]    A display unit  150  may display screen data at a preset transfer rate in a preset level of brightness under the control of the controller  100 . For example, the display unit  150  may display screen data transmitted at a User Interface (UI) rendering rate of 60 Hz in a level of brightness of 300 cd in a normal mode, and screen data transmitted at a UI rendering rate of 30 Hz in a level of brightness of 230 cd in a heat generation suppressing mode. 
         [0039]    A charging unit  160  may charge a battery (not shown) with preset charging current in a charge mode under the control of the controller  100 . For example, the charging unit  160  may charge a battery with charging current of 1 A in a normal mode, and with charging current of 450 mA in a heat generation suppressing mode under the control of the controller  160 . For example, the charging unit  160  may reduce the charging current from 1 A in a normal mode to 450 mA in a heat generation suppressing mode under the control of the controller  100 . If a charging amount of the battery is decreased to equal to or less than a lowest acceptable charging ratio (e.g., 20%) in a heat generation suppressing mode, the controller  100  may increase the charging current from 450 mA to 1 A so that the mobile device can be normally operated. Thereafter, if the battery is charged to an amount equal to or greater than a lowest acceptable charging ratio (e.g., 25%), the controller  100  may, for example, adjust the charging current from 1 A to 450 mA. 
         [0040]    The controller  100  may identify a normal mode or a heat generation suppressing mode according to a temperature detected by the temperature sensor  130 . The controller  100  may control the operations of the camera  140 , the display unit  150  and the charging unit  160  in a heat generation suppressing mode in order to reduce the amount of heat generated in the mobile device. Heat generation in the mobile device may be caused by continued operation of the controller  100 . For example, if the controller  100  executes an application that requires a large amount of load, e.g., a game, or a number of applications simultaneously, it may continually operate or become overloaded and accordingly generate a large amount of heat. In that case, the controller  100  may reduce the system clock. For example, the controller  100  may use up to the maximum system clock rate (e.g., 1.4 GHz) in a normal mode. However, it may only use up to a preset clock rate (e.g., 500 MHz) in a heat generation suppressing mode. 
         [0041]    The temperature on an outer surface of the mobile device may differ from the internal temperature of the mobile device detected by the temperature sensor  130 . The temperature on the outer surface of the mobile device that the mobile device user can feel and the internal temperature of the mobile device, as detected by the temperature sensor  130 , may be empirically measured, thereby setting a temperature to determine that a state in which an unacceptable heat is generated inside the mobile device. If, for example, the temperature sensor  130  is installed near the controller  100 , the outer surface temperature and the detected temperature may be acquired as described in the following Table 1. The outer surface temperature refers to a temperature on the outer surface of the mobile device. The detected temperature refers to an internal temperature of the mobile device that is detected by the temperature sensor  130  and corresponds to the outer surface temperature. 
         [0000]    
       
         
               
               
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
             
             
               
                   
                 Outer surface temperature [° C.] 
                 43 
                 45 
                 48 
                 50 
               
               
                   
                 Detected temperature [° C.] 
                 51 
                 54 
                 59 
                 61 
               
               
                   
                   
               
             
          
         
       
     
         [0042]    The detected temperature for concluding that the mobile device is overheated may be determined via a variety of methods. For example, concluding that the mobile device is overheated may be set via only a detected temperature. Alternatively, concluding that the mobile device is overheated may be set via a detected temperature and a period of time during which a corresponding detected temperature is maintained. For example, in order to conclude that the mobile device is overheated via only a detected temperature, if a detected temperature is 61° C. (or an outer surface temperature is 50° C.), the controller  100  may operate the mobile device in a heat generation suppressing mode. Regarding temperatures as described in Table 1, a suppression temperature Tw may be set to operate the mobile device in a heat generation suppressing mode by combining the detected temperature with a retention time. For example, the suppression temperature Tw may be set as in the following Table 2, and stored in the memory  110 . 
         [0000]    
       
         
               
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
             
             
               
                 Detected temperature Tw [° C.] 
                 51 
                 54 
                 59 
                 61 
               
               
                 Retention time 
                 4 hrs 
                 30 mins 
                 5 mins 
                 Immediately 
               
               
                   
               
             
          
         
       
     
         [0043]    As described in Table 2, the detected temperature Tt refers to a temperature that the temperature sensor  130  detects inside the mobile device, i.e., an internal temperature. When a detected temperature, as described in Table 2, is maintained for a corresponding amount of time, i.e., a retention time, the controller  100  may compare it with a preset temperature, Tw, and execute a heat generation suppressing mode. In that case, the controller  100  may count the retention time via an internal timer. If the controller  100  ascertains that the detected temperature is altered, it may alter the corresponding retention time and determine a temperature and a time period. 
         [0044]    Because the mobile device includes a camera  140 , a display unit  150 , a charging unit  160  and a controller  100 , which serve as causes of heat generation, operations in a normal mode and a heat generation suppressing mode may be defined as in the following Table 3. 
         [0000]    
       
         
               
               
               
             
               
               
               
             
           
               
                   
                 TABLE 3 
               
               
                   
                   
               
               
                   
                   
                 Heat generation suppressing 
               
               
                   
                 Normal mode 
                 mode 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                 Transfer rate/Resolution of 
                 30 fps/1080 p 
                 15 fps/720 p 
               
               
                 Camera 
               
               
                 Data reception rate/Brightness of 
                 60 Hz/300 cd 
                 30 Hz/230 cd 
               
               
                 Display unit 
               
               
                 Charging current of Charging 
                 1 A 
                 450 mA 
               
               
                 unit 
               
               
                 System clock of Controller 
                 1.4 GHz 
                 500 MHz 
               
               
                   
               
             
          
         
       
     
         [0045]    As described in Table 3, the camera  140  may acquire a video of 1080 pixels at 30 frames per second in a normal mode, and a video of 720 pixels at 15 frames per second in a heat generation suppressing mode. Therefore, the camera  140  may reduce the generation of heat in a heat generation suppressing mode as compared with a normal mode. The display unit  150  may receive frame data at 60 Hz from the buffer of the controller  100  and display it at a level of brightness of 300 cd in a normal mode. The display unit  150  may also receive frame data at 30 Hz from the buffer of the controller  100  and display it at a level of brightness of 230 cd in a heat generation suppressing mode. Therefore, the display unit  150  may reduce the generation of heat in a heat generation suppressing mode as compared with a normal mode. The charging unit  160  may charge the battery with charging current of 1 A in a normal mode, and 450 mA in a heat generation suppressing mode. Therefore, the charging unit  160  may reduce the generation of heat during the charging operation. The controller  100  may use a system clock rate of maximum 1.4 GHz in a normal mode, and system clock rate of maximum 500 MHz in a heat suppressing mode. Therefore, the controller  100  may reduce the generation of heat. 
         [0046]    As the temperature Tw is employed to set a heat generation suppressing mode, a temperature for releasing the heat generation suppressing mode, Ts, may be required that is called a release temperature. The release temperature Ts may be set as a specific detected temperature. For example, the release temperature Ts may be set to 50° C. or 51° C. Alternatively, the release temperature Ts may be set as a preset temperature to which a detected temperature Tt is lowered during the heat generation suppressing mode. That is, if a set temperature Tw is determined as described in Table 2, the release temperature Ts may be set as a temperature less than the currently detected temperature Tt. For example, if the detected temperature Tt is lowered from 61° C. to 59° C., from 59° C. to 54° C., from 54° C. to 51° C., and to less than 51° C.; or from 61° C. to 54° C., from 59° C. to 51° C., and to less than 51° C., these temperature may be set as a release temperature Ts. 
         [0047]      FIG. 2  illustrates a flowchart that describes a method for controlling a temperature of a mobile device according to an exemplary embodiment of the present invention. It is assumed that the heat generation modules are a controller  100 , a camera  140 , a display unit  150  and a charging unit  160 . The operations in a normal mode and a heat generation suppressing mode are defined as Table 3. 
         [0048]    Referring to  FIG. 2 , in a normal mode in step  211 : the controller  100  may use the maximum system clock, the camera  140  may acquire a video at the maximum frame rate with the maximum resolution, the display unit  150  may receive screen data from the controller  100  at the maximum transfer rate and display it with the highest level of brightness, and the charging unit  160  may charge the battery with the maximum charging current in a charging mode. The controller  100  may receive an internal temperature of the mobile device, detected by the temperature sensor  130 , and analyze it in step  213 . The controller  100  may determine whether the detected temperature Tt is greater than a set temperature Tw to execute a normal mode or a heat generation suppressing mode in step  215 . The analysis of the detected temperature, at steps  213  and  215 , is described as follows, referring to  FIG. 3 . 
         [0049]      FIG. 3  illustrates a flowchart that describes a method for analyzing an internal temperature of the mobile device and determining whether a heat generation suppressing mode is executed according to an exemplary embodiment of the present invention. 
         [0050]    Referring to  FIG. 3 , the controller  100  may receive the output from the temperature sensor  130  at a measure of time and analyze the internal temperature of the mobile device. If it is determined that a preset period of time to detect has elapsed in step  311 , the controller  100  may control the temperature sensor  130  to detect the internal temperature of the mobile device and receive it in step  313 . The controller  100  may analyze the detected temperature at steps  315  to  319 . If the set temperature Tw matches a first set temperature Tw 1  as described in Table 2, the controller  100  may execute an immediate heat generation suppressing mode. If the set temperature Tw matches a second set temperature Tw 2  as described in Table 2, the controller  100  may execute a heat generation suppressing mode so that the second set temperature Tw 2  is maintained for the corresponding period of time. As described in Table 2, the first set temperature Tw 1  may be 61° C. the second set temperature Tw 2  may be 59° C., 54° C., and 51° C. and the retention time may be 5 mins, 30 mins, and 4 hours. Therefore, if the controller  100  detects the first set temperature Tw 1  via the temperature sensor  130  in step  315 , it may execute a heat generation suppressing mode to control the temperature of the mobile device in step  317 . 
         [0051]    On the contrary, if the controller  100  detects the second set temperature Tw 2  in step  319 , it may determine whether the second set temperature Tw 2  is maintained in the mobile device for the corresponding period of time in step  321 . If the controller  100  ascertains that the second set temperature Tw 2  is maintained in the mobile device for the corresponding period of time at step  321 , it may execute a heat generation suppressing mode at step  317 . On the contrary, if the controller  100  ascertains that the second set temperature Tw 2  is not maintained in the mobile device for the corresponding period of time at step  321 , it may increase the retention time in step  323  and return to the process of  FIG. 2 . For example, as described in Table 2, if the second set temperature Tw 2  is 59° C., the controller  100  may determine whether 5 minutes has elapsed at step  321 . If the controller  100  ascertains that 5 minutes has elapsed at step  321 , it may execute a heat generation suppressing mode at step  317 . On the contrary, if 5 minutes has not elapsed at step  321 , the controller  100  may increase the retention time and return to the process of  FIG. 2 . Likewise, if the second set temperature Tw 2  is 54° C., the controller  100  may determine whether 30 minutes has elapsed at step  321 . If the controller  100  ascertains that 30 minutes has elapsed at step  321 , it may execute a heat generation suppressing mode at step  317 . On the contrary, if 30 minutes has not elapsed at step  321 , the controller  100  may increase the retention time and return to the process of  FIG. 2  where it executes a normal mode. Likewise, if the second set temperature Tw 2  is 51° C., the controller  100  may determine whether 4 hours has elapsed at step  321 . If the controller  100  ascertains that 4 hours has elapsed at step  321 , it may execute a heat generation suppressing mode at step  317 . On the contrary, if 4 hours has not elapsed at step  321 , the controller  100  may increase the retention time and return to the process of  FIG. 2  where it executes a normal mode. However, if the detected temperature Tt is less than the second set temperature Tw 2 , the controller  100  may return to the process of  FIG. 2  and executes a normal mode. 
         [0052]    During the temperature analysis, if the internal temperature of the mobile device increases (e.g., from 51° C. to 54° C. or from 54° C. to 59° C.), the controller  100  may alter the retention time to a retention time corresponding to the increased temperature and re-analyze the temperature. If, for example, the internal temperature of the mobile device changes from 59° C. to 61° C., the controller  100  may immediately execute a heat generation suppressing mode irrespective of the retention time. If the internal temperature of the mobile device decreases (e.g., from 61° C. to 59° C., from 59° C. to 54° C., or from 54° C. to 51° C.), the controller  100  may alter the retention time to a retention time corresponding to the decreased temperature and re-analyze the temperature. If the internal temperature of the mobile device increases or decreases, the controller  100  may wait for a certain period of time (e.g., 30 seconds, 1 minute, or the like), and then perform the next process. 
         [0053]    Referring back to  FIG. 2 , if it is determined that the detected temperature Tt is greater than a set temperature Tw at step  215 , the mobile device may execute a heat generation suppressing mode to reduce its internal temperature in step  217 . During the heat generation suppressing mode, as described in Table 3, the frame rate and the number of pixels of the camera  140 , the transfer rate of screen data and the level of brightness of the display unit  150 , the charging current of a charging unit  160  in a charging mode, and the system clock of the controller  100 , may be set to corresponding values, respectively. When the mobile device enters a heat generation suppressing mode, the internal temperature starts to decrease. While the internal temperature is decreasing during the heat generation suppressing mode, the controller  100  receives the internal temperature analyzed by the temperature sensor  130  in step  219 . The controller  100  determines whether the detected temperature Tt of the temperature sensor  130  is less than a release temperature Ts in step  221 . 
         [0054]    The release temperature Ts may be fixed to only a preset release temperature (e.g., 51° C. as described in Table 2). Alternatively, the release temperature Ts may be used as one of a number of release temperatures, like the set temperatures, together with corresponding time periods. In an exemplary embodiment of the present invention, the release temperature Ts may be fixed to only one release temperature. If it is determined that the detected temperature Tt is greater than the release temperature Ts at step  221 , the controller  100  may return to step  217  and execute a heat generation suppressing mode. On the contrary, if the detected temperature Tt is less than the release temperature Ts at step  221 , the controller  100  may return to step  211  and execute a normal mode. For example, if the controller  100  ascertains that the internal temperature of the mobile device is less than the release temperature Ts, it may control the camera  140 , charging unit  160  and the processor in a normal mode, based on the values described in Table 2. 
         [0055]    If the controller  100  detects a set temperature Tw to execute a heat generation suppressing mode during the normal mode, it may control the operations of the modules (e.g., camera, display unit, charging unit, and processor, and the like) that emit heat in the mobile device. If the internal temperature of the mobile device increases to a set temperature Tw during the normal mode, the controller  100  may analyze the heat generation causes and selectively control corresponding modules. 
         [0056]      FIG. 4  illustrates a flowchart that describes a method for selectively controlling heat generation causes when the temperature increases in the mobile device and decreasing the internal temperature, according to an exemplary embodiment of the present invention. 
         [0057]    Referring to  FIG. 4 , the controller  100  may execute a normal mode in step  411 , receive the internal temperature detected via the temperature sensor  130 , as described above referring to  FIG. 3 , in steps  413  and  415 , and analyze the internal temperature. The internal temperature may be analyzed as the same process as described above referring to  FIG. 3 . If the detected temperature Tt is greater than a set temperature Tw, the controller  100  may analyze the heat generation cause in step  417 . For example, if the temperature increases in the mobile device, the controller  100  may analyze the currently executed applications, detect modules that increase the internal temperature, and operate the modules in a heat generation suppressing mode. 
         [0058]    If the cause for heat generation corresponds to a camera  140 , the controller  100  may operate the camera  140  in a heat generation suppressing mode via the following steps  419  and  421 . If the heat generation cause corresponds to a display unit  150 , the controller  100  may operate the display unit  150  in a heat generation suppressing mode via the following steps  423  and  425 . If the cause for heat generation corresponds to a charging unit  160  in a charge mode, the controller  100  may operate the charging unit  160  in a heat suppressing mode via the following steps  427  and  429 . If the cause for heat generation corresponds to a continued use of the controller  100 , the controller  100  may control the system clock in a heat generation suppressing mode via the following steps  431  and  433 . In an exemplary embodiment of the present invention, the camera  140 , the display unit  150 , the charging unit  160  and the system clock in a heat generation suppressing mode may be set to the values as described in Table 3. 
         [0059]    If there are a number of causes for heat generation that have been analyzed at step  417 , the controller  100  may control the corresponding modules in a heat generation suppressing mode. After performing steps  433  or  435 , the controller  100  may receive the internal temperature of the mobile device, detected via the temperature sensor  130 , and analyze it at step  435 . The controller  100  may determine whether the detected temperature Tt is equal to or less than a release temperature Ts at step  437 . If the controller  100  ascertains that the detected temperature Tt is equal to or less than a release temperature Ts at step  437 , it may release the heat generation suppressing mode and return to step  411  where it executes a normal mode. On the contrary, if the controller  100  ascertains that the detected temperature Tt is greater than a release temperature Ts at step  437 , it may return to step  417  and maintain the heat generation suppressing mode. 
         [0060]    In an exemplary embodiment of the present invention, the set temperature Tw may be set to first set temperature Tw 1  and second set temperature Tw 2 . If the detected temperature Tt is a first set temperature Tw 1  (e.g., 61° C. as described in Table 2), the controller  100  may operate all the modules in the mobile device (e.g., camera, display unit, charging unit, and processor) in a heat generation suppressing mode. If the detected temperature Tt is between a first set temperature Tw 1  and a second set temperature Tw 2  (e.g., one of 51° C., 54° C. and 59° C. as described in Table 2), the controller  100  may identify modules that emit heat in the mobile device and operate the identified modules in a heat generation suppressing mode. 
         [0061]      FIG. 5  illustrates a schematic block diagram according to an exemplary embodiment of the present invention. 
         [0062]    Referring to  FIG. 5 , the communication unit  120  may communicate with a base station or other external systems in wireless mode. The communication unit  120  may be configured with substantially the same components as the communication unit of  FIG. 1  and thus perform the same or similar functions. 
         [0063]    The controller  100  may control operations of the mobile device and perform a temperature control operation according to an exemplary embodiment of the present invention. 
         [0064]    The memory  110  may include a program storage memory and a data storage memory. The program storage memory may store an Operating System (OS) of the mobile device and application programs. The data storage memory may store tables related to the operations of the mobile device and data created when the application programs are executed. The memory  110  may store a table for setting temperature values and/or the corresponding temperature retention times to determine whether the mobile device is overheated. 
         [0065]    The temperature sensor  105  may be installed near the controller  100 . The temperature sensor  105  may detect the internal temperature in the mobile device and transfer it to the controller  100 . Heat generation in the mobile device may be caused by overload of the controller  100 . For example, if the controller  100  executes an application that requires a large amount of processing, e.g., a game, or a number of applications simultaneously, it may become overloaded and accordingly generate a large amount of heat. In that case, the temperature sensor  105  may detect the temperature near the controller  100  and transfer it to the controller  100 . As such, if the controller  100  ascertains that it is overheated, it may reduce the system clock speed. For example, the controller  100  may use up to the maximum system clock rate (e.g., 1.4 GHz) in a normal mode. However, it may use only up to a preset clock rate (e.g., 500 MHz) in a heat generation suppressing mode. 
         [0066]    The camera  140  may acquire video data at a preset frame rate and with a preset resolution in a camera operation mode under the control of the controller  100 . The temperature sensor  145  may detect a temperature of the camera  140  and transfer it to the controller  100 . The controller  100  may operate the camera  140  in a normal mode or a heat generation suppressing mode according to the temperature detected via the temperature sensor  145 . For example, the camera  140  may acquire a video, at 30 frames per sec (30 fps), with a resolution of 1080 pixels in a normal mode, and a video at 15 fps with a resolution of 720 pixels in a heat generation suppressing mode. 
         [0067]    The display unit  150  may display screen data at a preset transfer rate and a preset level of brightness under the control of the controller  100 . The temperature sensor  155  may detect the temperature of the display unit  150  and transfer it to the controller  100 . The controller  100  may operate the display unit  150  in a normal mode or a heat generation suppressing mode according to the temperature detected via the temperature sensor  155 . For example, the display unit  150  may display screen data transmitted at a UI rendering rate of 60 Hz at a level of brightness of 300 cd in a normal mode and screen data transmitted at a UI rendering rate of 30 Hz at a level of brightness of 230 cd in a heat generation suppressing mode. 
         [0068]    The temperature sensor  165  may detect the temperature of the charging unit  160  and transfer it to the controller  100 . The controller  100  may operate the charging unit  160  in a normal mode or a heat generation suppressing mode according to the temperature detected via the temperature sensor  165 . The charging unit  160  may charge a battery (not shown) with preset charging current in a charge mode under the control of the controller  100 . For example, the charging unit  160  may charge a battery with a charging current of 1 A in a normal mode, and with a charging current of 450 mA in a heat generation suppressing mode under the control of the controller  160 . For example, the charging unit  160  may reduce the charging current from 1 A in a normal mode to 450 mA in a heat generation suppressing mode under the control of the controller  160 . If an amount of charge in the battery is decreased to equal to or less than a lowest acceptable charging ratio (e.g., 20%) in a heat generation suppressing mode, the controller  100  may increase the charging current from 450 mA to 1 A so that the mobile device can be normally operated. Thereafter, if the battery is charged with a charging amount equal to or greater than a lowest acceptable charging ratio (e.g., 25%), the controller  100  may adjust the charging current from 1 A to 450 mA, for example. 
         [0069]    The controller  100  may determine whether the modules (e.g., the controller  100 , the camera  140 , the display unit  150 , and the charging unit  160 ) are required to operate in a normal mode or a heat generation suppressing mode according to the temperatures detected via the temperature sensors  105 ,  145 ,  155 , and  165 , respectively. In order to reduce the internal temperature of the mobile device, the controller  100  may control the system clock, the camera  140 , the display unit  150  and the charging unit  160  to operate in a heat generation suppressing mode. 
         [0070]    In another exemplary embodiment of the present invention, shown in  FIG. 5 , the controller  100  may detect the temperatures of the respective modules and control corresponding modules that are overheated, thereby preventing the mobile device from being overheated. To this end, the controller  100  may control the temperature of the mobile device in the same processes as the method of  FIG. 4 . 
         [0071]    The controller  100  may execute a normal mode at step  411 . The controller  100  may receive the temperatures of the respective modules detected via the temperature sensors  105 ,  145 , and  155 , and analyze them at steps  413  and  415 . The controller  100  may also receive a temperature of the charging unit  160  in a charging mode, detected via the temperature sensor  165 . The charging unit  160  may execute the charging mode when the mobile device operates in a normal mode. Alternatively, the charging unit  160  may also execute the charging mode when the mobile device is turned off. In the following description, it is assumed that the charging unit  160  executes the charging mode when the mobile device operates in a normal mode. If the detected temperature Tt, detected by the temperature sensor(s)  105 ,  145   155  and/or  165 , is greater than a set temperature Tw, the controller  100  may operate the corresponding module(s) in a heat generation suppressing mode. 
         [0072]    If the heat generation cause corresponds to a camera  140 , the controller  100  may operate the camera  140  in a heat generation suppressing mode. If the cause for heat generation corresponds to a display unit  150 , the controller  100  may operate the display unit  150  in a heat generation suppressing mode. If the heat generation cause corresponds to a charging unit  160 , the controller  100  may operate the charging unit  160  in a heat generation suppressing mode. If the heat generation cause corresponds to a system overload, the controller  100  may control the system clock in a heat generation suppressing mode. In another exemplary embodiment of the present invention, the camera  140 , display unit  150 , charging unit  160  and the system clock in a heat generation suppressing mode may be set to the values as described in Table 3. 
         [0073]    If there are a number of heat generation causes, the controller  100  may control the corresponding modules in a heat generation suppressing mode. If the controller  100  ascertains that the mobile device is in an overheated state, it may operate corresponding modules that provide heat generation causes in a heat generation suppressing mode. The controller  100  may receive the temperatures of the modules operating in a heat generation suppressing mode via the temperature sensors respectively, and analyze them. The controller  100  may determine whether the detected temperatures Tt of the modules are equal to or less than release temperatures Ts, respectively. If the controller  100  ascertains that the detected temperatures Tt are equal to or less than release temperatures Ts respectively, it may release the heat generation suppressing mode of a corresponding module and operate it in a normal mode. On the contrary, if the controller  100  ascertains that the detected temperatures Tt are greater than release temperatures Ts respectively, it may maintain the heat generation suppressing mode of a corresponding module. 
         [0074]    As described above, the mobile device is equipped with a variety of modules that may cause heat generation, and a sensor (e.g., a thermistor) for detecting the temperature inside the mobile device. The sensor may be located near the heat generation sources. The temperature sensor may detect the temperature according to heat from a processor and other parts in the mobile device. The exemplary system and method according to the invention controls the operations of a corresponding module and thus prevents the temperature in the mobile device from rising. Therefore, the exemplary system and method may prevent use interruptions or low temperature burns caused as the mobile device is overheated. For example, the exemplary system and method may control the operations of a processor, an LCD module, a camera module, a charger, and the like, as causes of heat generation in the mobile device, and thus prevent the outer surface of the mobile device from being overheated. 
         [0075]    While the invention has been shown and described with reference to certain exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and their equivalents.