Abstract:
An electronic device includes: a secondary battery; a terminal, which receives electric power to charge the secondary battery; a switch, which turns on and off a connection between the secondary battery and the terminal; and a controller, which controls the switch to be turned off for a predetermined period at a time of starting to charge the secondary battery.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority from Japanese Patent Application No. 2015-133188 filed on Jul. 2, 2015, the entire subject matter of which is incorporated herein by reference. 
       TECHNICAL FIELD 
       [0002]    This disclosure relates to an electronic device, a charging apparatus, a charging program, and a charging method. 
       BACKGROUND 
       [0003]    In the background art, a secondary battery such as a lithium battery is used in an electronic device such as a smart phone. In such an electronic device, a technique has been known which eliminates affects of heat generation at the time of charging of the secondary battery. 
       SUMMARY 
       [0004]    According to one aspect of this disclosure, an electronic device includes: a secondary battery; a terminal, which receives electric power to charge the secondary battery; a switch, which turns on and off a connection between the secondary battery and the terminal; and a controller, which controls the switch to be turned off for a predetermined period at a time of starting to charge the secondary battery. 
         [0005]    According to another aspect of this disclosure, a charging apparatus includes: a terminal, which is used to supply electric power to a secondary battery; a detector, which detects a current flowing to the terminal; a switch, which turns on and off a connection between the secondary battery and the terminal; and a controller, which controls the switch to be turned off if the detector detects a current for a predetermined period at a time of starting to charge the secondary battery. 
         [0006]    According to another aspect of this disclosure, a non-transitory computer-readable medium having instructions to control electronic device to perform operations includes: detecting a start of charging of a secondary battery; and controlling a switch connected to the secondary battery to be turned off for a predetermined period at a time of starting to charge the secondary battery. 
         [0007]    According to another aspect of this disclosure, a non-transitory computer-readable medium having instructions to control electronic device to perform operations comprising: detecting a current flowing to a terminal which is used to supply charging power to a secondary battery; and turning off a switch for a predetermined period at a time of starting to charge the secondary battery if the current is detected in the detecting. 
         [0008]    According to another aspect of this disclosure, a charging method comprising: detecting a start of charging of a secondary battery; and controlling a switch connected to the secondary battery to be turned off for a predetermined period at a time of starting to charge the secondary battery. 
         [0009]    According to another aspect of this disclosure, a charging method includes: detecting a current flowing to a terminal which is used to supply charging power to a secondary battery; and turning off a switch for a predetermined period at a time of starting to charge the secondary battery when the current is detected in detecting. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The foregoing and additional features and characteristics of this disclosure will become more apparent from the following detailed descriptions considered with the reference to the accompanying drawings, wherein: 
           [0011]      FIG. 1  is a schematic diagram of a charging system to which an electronic device of an embodiment of this disclosure is applied; 
           [0012]      FIG. 2  is a block diagram of an internal configuration of a smart phone  105  illustrated in  FIG. 1 ; 
           [0013]      FIG. 3  is a block diagram of an internal configuration of a charger  103  illustrated in  FIG. 1 ; 
           [0014]      FIG. 4  is a schematic diagram illustrating a connection state of the charging system illustrated in  FIG. 1 ; 
           [0015]      FIG. 5  is a timing chart for operation of the charging system illustrated in  FIG. 1 ; 
           [0016]      FIG. 6  is a timing chart for operation of the charging system illustrated in  FIG. 1 ; 
           [0017]      FIG. 7  is a flowchart for operation of the charging system illustrated in  FIG. 1 ; and 
           [0018]      FIG. 8  is a schematic diagram illustrating a modified connection state of the charging system to which the electronic device according to an embodiment of this disclosure is applied. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    In some embodiments of electronic device will be described below with reference to the accompanying drawings.  FIG. 1  is a schematic diagram of a charging system to which electronic device of this embodiment is applied. The following description also explains an embodiment of a charging program and a charging method of this disclosure. 
         [0020]    In the electronic device, it is expected to further improve safety at the time of charging of the secondary battery. 
         [0021]    This disclosure provides an electronic device, a charging apparatus, a charging program, and a charging method that is able to realize improvement of safety. 
         [0022]    In  FIG. 1 , reference numeral  101  denotes a receptacle outlet, reference numeral  103  denotes a charger, and reference numeral  105  denotes a smart phone serving as an electronic device of an embodiment. Electric power from the receptacle outlet  101  may be supplied to the smart phone  105  through a cable  103   a  of the charger  103 . The charger  103  and the smart phone  105  may be connected to each other by a microUSB terminal, etc. 
         [0023]    An internal configuration of the smart phone  105  illustrated in  FIG. 1  will be described below with reference to  FIG. 2 .  FIG. 2  is a block diagram of the internal configuration of the smart phone  105  illustrated in  FIG. 1 . 
         [0024]    As illustrated in  FIG. 2 , the smart phone  105  may include a controller (for example, CPU)  202  that controls the entire apparatus and a storage unit  204  that stores, for example, a charging program of an embodiment and other programs or data. The smart phone  105  further may include a display unit  206  that is configured by, for example, a touch panel display for displaying images, characters, or the like, and a communication unit  208  that performs communication with an external apparatus using a short-distance wireless communications or a LAN cable, for example. 
         [0025]    The smart phone  105  further may include an input unit  210  made up of a button for ON/OFF operation of a power supply, a button for volume adjustment, and other operation buttons. The smart phone  105  further may include an interface unit  212  configured to be connected to external device such as the charger  103  by, for example, the microUSB. 
         [0026]    The smart phone  105  further may include a secondary battery  214  that supplies electric power to the entire apparatus. The secondary battery  214  may be detachable. The secondary battery  214  is used as a power supply of the smart phone  105  in an embodiment, but may be a battery other than a lithium battery as long as storing electricity by charging and being able to be used as a battery. 
         [0027]    The smart phone  105  further may include a switch  216  that switches to turn ON and OFF the charging power supplied from the charger  103 . 
         [0028]    An internal configuration of the charger  103  illustrated in  FIG. 1  will be described below with reference to  FIG. 3 .  FIG. 3  is a block diagram of the internal configuration of the charger illustrated in  FIG. 1 . 
         [0029]    As illustrated in  FIG. 3 , the charger  103  may include a rectifier  301  that may rectifie a current supplied from the receptacle outlet  101 , a switching unit  303  that may convert a DC voltage into an AC voltage having a necessary duty cycle, a transformer  305  that may convert the AC voltage, and a controller  307  that may control the switching unit  303  or the like. The charger  103  may receive the electric power from an in-side terminal and outputs the electric power from an out-side terminal. 
         [0030]    The charger  103  further may include a current detector  309  that detects a current flowing to a charging terminal for the smart phone  105  and a switch  311  that may switch on and off the current flowing to the charging terminal for the smart phone  105 . 
         [0031]    A connection state of the charging system illustrated in  FIG. 1  will be described below with reference to  FIG. 4 .  FIG. 4  is a schematic diagram illustrating a connection state of the charging system illustrated in  FIG. 1 . For the description of the connection relation,  FIG. 4  illustrates only a part of the charging system illustrated in  FIG. 1 . 
         [0032]    In  FIG. 4 , the charger  103  and the smart phone  105  may be connected to each other. In the charger  103 , the switch  311  and the current detector  309  may be connected. Terminals  407   a  and  407   b  may be provided to be connected to the smart phone  105  and supply the electric power to the smart phone from the charger  103 . 
         [0033]    The smart phone  105  may be provided with a load circuit  405  including the display unit, the communication unit, and the like, in addition to the switch  216  and the secondary battery  214 . The load circuit  405  may be connected to the switch  216  and the secondary battery  214 . The smart phone  105  may include a connector  403  that may be connected to the terminals  407   a  and  407   b  of the charger  103 . The smart phone  105  may include terminals  409   a  and  409   b  connected to the terminals  407   a  and  407   b  of the charger  103 . 
         [0034]    In some embodiments, it is assumed that an abnormal portion  401  has occurred between the terminals  407   a  and  407   b  of the charger  103 . As the abnormal portion  401 , for example, there is a short circuit between the terminals  407   a  and  407   b  or an electric leakage in the terminals  407   a  and  407   b.  Naturally, the abnormal portion  401  of an embodiment is not limited to the short circuit or the electric leakage, and may be any abnormality, for example, contamination of a foreign material such as water or dust. In some embodiments, as an example, the abnormal portion  401  due to the short circuit between the terminals  407   a  and  407   b  will be described below. It is assumed that the abnormal portion  401  has a function equivalent to resistance. 
         [0035]    Information such as control signals may be exchanged between the charger  103  and the smart phone  105  through the terminals  407   a  and  407   b.    
         [0036]    Operation of the charging system illustrated in  FIG. 1  will be described below with reference to  FIGS. 4, 5, 6, and 7 .  FIGS. 5 and 6  are timing charts for operation of the charging system illustrated in  FIG. 1 .  FIG. 5  illustrates a timing chart in a case where abnormality does not occur in the charging system;  FIG. 6  illustrates a timing chart in a case where abnormality occurs in the charging system; and  FIG. 7  is a flowchart for operation of the charging system illustrated in  FIG. 1 . 
         [0037]    The controller  202  of the smart phone  105  may control to start charging when the smart phone  105  and the charger  103  may be connected to each other (step S 701 ). 
         [0038]    The controller  202  may control ON/OFF operations of the switch  216  (step S 703 ). The switch may be turned ON/OFF only once and may be repeatedly turned ON/OFF several times after the charger  103  is connected to the smart phone  105 . In some embodiments, the controller  202  may maintain the switch  216  in the ON state in an initial state where the charger  103  is not connected to the smart phone  105 . Naturally, the controller  202  may maintain the switch  216  in the OFF state in the initial state. The controller  202  may control to turn OFF the switch  216  for a short time. 
         [0039]    Subsequently, the controller  307  of the charger  103  may determine whether to detect a current using the current detector  309  when the switch  216  is in the OFF state (step S 705 ). 
         [0040]    If the current is detected (“Yes” in step S 705 ), the controller  307  may turn OFF the switch  311  and stops the charging (step S 707 ). If the current is not detected (“No” in step S 705 ), the controller  307  may continue to turn ON the switch  311  to continue the charging (step S 711 ) and ends the operation. 
         [0041]    Next, after stopping the charging, the controller  307  may notify the smart phone  105  of the fact that the current is detected (step S 709 ) and ends the operation. 
         [0042]    An operation of the charging system illustrated in  FIG. 1  will be further described below. 
         [0043]    1) Operation in the Normal State 
         [0044]    When the switch  216  is turned off, the current detected by the current detector  309  becomes zero (time T 1  or T 2  in  FIG. 5 ), even under the charging. The controller  307  may determine that the operation is normal by detection of the time T 1  or T 2  during which the current becomes zero. 
         [0045]    2) Operation in the Abnormal State 
         [0046]    When a current flows through a path other than an original charging path due to, for example, the presence of the abnormal portion  401 , the current continuously flows between the terminal  407   a  and the terminal  407   b  even when the switch  216  is turned off. In this case, the current detector  309  may detect a current even after a certain period from the start of charging, and also may detect a current while the switch  216  is being tuned OFF (time T 3  in  FIG. 6 ). The controller  307  may determine that the abnormal occurs if the current is detected at a time period in which the current will not be detected if the operation is normal. The controller  307  may turn off the switch  311  and stops the charging (current supply) if it is determined that the abnormal occurs. 
         [0047]    In this way, according to the charging system using the electronic device of an embodiment, the of presence or absence of abnormality occurrence is detected depending on whether the current is detected, and thus a temperature sensor or the like may be not necessary for detection of heat generation. 
         [0048]    Therefore, according to the charging system using the electronic device of an embodiment, it may be not necessary to mount a plurality of sensor devices with assuming the heat generation in various places, and thus it is advantageous in cost as compared with a case where a sensor is mounted. 
         [0049]    According to the charging system employing the electronic device of an embodiment, the charger  103  can detect an abnormal state. For this reason, the charger  103  can activate a protective circuit such as a current stopping switch. 
         [0050]    This disclosure provides an electronic device, charging apparatus, a charging program, and a charging method that is able to realize improvement of safety. 
         [0051]    The charging system to which the electronic device according to an embodiment of this disclosure is applied is not limited to the above configuration. An example of the charging system to which the electronic device according to an embodiment of this disclosure is applied will be described with reference to  FIG. 8 .  FIG. 8  is a schematic diagram illustrating a connection state of a modified charging system to which the electronic device according to an embodiment of this disclosure is applied. 
         [0052]    In the charging system illustrated in  FIG. 8 , an abnormal portion  801  occurs inside a connector  403  of a smart phone  105 . It is assumed that such an abnormal portion  801  occurs when a foreign material such as water or dust enters into the connector  403 , but the abnormal portion  801  according to the modified example will not be limited thereto. The operation of the charging system illustrated in  FIG. 8  is similar to that of the charging system described with reference to  FIGS. 1 to 7 . 
         [0053]    The charging system illustrated in  FIG. 8  also has the same effect as the charging system described with reference to  FIGS. 1 to 7 . 
         [0054]    This disclosure can be variously changed without being limited to an embodiment described above. For example, the controller  307  may reduce the amount of current supply in the charging when determining to be abnormal based on the detection of the current at a time period in which the current will not be detected if the operation is normal. 
         [0055]    Although the disclosure is based on some embodiments and the accompanying drawings, it is to be noted that various changes and modifications will be apparent to those skilled in the art based on this disclosure. Therefore, such changes and modifications may be understood as included within the scope of this disclosure. For example, in some functions and structural components and the like of some embodiments may be reordered in any logically consistent way. Furthermore, the functions and the structural components may be combined into some embodiments or divided from an embodiment.