Abstract:
An appliance includes a driver to drive a load, the load requiring AC power or DC power. A power supply receives one of external AC power, back-up AC power and back-up DC power and outputs at least one of AC power or DC power to the load. An operation mode of the home appliance is one of normal operation when receiving external AC power, normal operation when receiving one of back-up AC power and back-up DC power during a power interruption, and a power save mode when receiving one of back-up AC power and back-up DC power during the power interruption. The power supplies a first power level when there is no power interruption, a second power level when there is power interruption and a third power level when there is power interruption and the power save mode is selected, where the second power level is between the first power level and the third power level. The power save mode is automatically selected when the second power level falls below a reference power level.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority under 35 U.S.C. §119 to Korean Patent Application Nos. 10-2014-0110621 filed Aug. 25, 2014 and 10-2014-0125592 filed on Sep. 22, 2014 in the Korean Intellectual Property Office, whose entire disclosures are hereby incorporated by reference. 
       BACKGROUND 
       [0002]    1. Field 
         [0003]    The present disclosure relates to a home appliance and an operating method thereof, and more particularly, to a home appliance and an operating method thereof, which are capable of simply informing of an operation mode upon interruption of electric power. 
         [0004]    2. Background 
         [0005]    Among home appliances installed in a building, for convenience of users, refrigerators function to store food, laundry treating appliances function to treat laundry, air conditioners function to adjust room temperature, and cooking appliances function to cook food. Meanwhile, among such home appliances, refrigerators must continuously operate through continuous supply of electric power thereto. To this end, a variety of research is being conducted to stably operate such a refrigerator even when supply of electric power is unstable, in particular, during interruption of electric power. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    The embodiments will be described in detail with reference to the following drawings in which like reference numerals refer to like elements wherein: 
           [0007]      FIG. 1  is a view illustrating an example of supply of electric power to a home appliance according to an embodiment of the present disclosure; 
           [0008]      FIG. 2  is a block diagram roughly illustrating an inner configuration of the home appliance illustrated in  FIG. 1 ; 
           [0009]      FIGS. 3A to 3F  are views explaining various examples of the home appliance; 
           [0010]      FIG. 4  is a view roughly illustrating a configuration of a refrigerator illustrated in  FIG. 3A ; 
           [0011]      FIG. 5  is a block diagram illustrating an example of an inner configuration of a power supply illustrated in  FIG. 2 ; 
           [0012]      FIG. 6  is a flowchart illustrating an operating method of the home appliance according to an embodiment of the present disclosure; 
           [0013]      FIGS. 7 and 8  are views explaining the operating method of  FIG. 6 ; 
           [0014]      FIG. 9  is a view illustrating supply of electric power to a home appliance according to another embodiment of the present disclosure; 
           [0015]      FIG. 10  is a view illustrating supply of electric power to a home appliance according to another embodiment of the present disclosure; 
           [0016]      FIG. 11  is a flowchart illustrating an operating method of the home appliance according to another embodiment of the present disclosure; and 
           [0017]      FIGS. 12A to 12E  are views explaining the operating method of  FIG. 11 . 
       
    
    
     DETAILED DESCRIPTION 
       [0018]      FIG. 1  illustrates an example of supply of electric power to a home appliance according to an embodiment of the present disclosure. The refrigerator power supply system  10  may include a home appliance  100 , a grid  70 , and an uninterruptible power supply (UPS)  50 . The grid  70  supplies commercial AC power AC 1  to the home appliance  100  via a first power line Pln. 
         [0019]    The UPS  50  may be connected to the first power line Pln in parallel in order to cope with a situation in which commercial AC power supplied from the grid  70  has an unstable level or supply of the commercial AC power is interrupted. In  FIG. 1 , parallel connection of a second power line Pli to the first power line Pln is illustrated. 
         [0020]    The UPS  50  may determine interruption of electric power when AC power applied via the second power line Pli has a level equal to or lower than a predetermined level. In this case, the UPS  50  may supply DC power DC 1  stored in an internal battery to the home appliance  100  via a third power line Pld. 
         [0021]    In a normal state other than interruption of electric power, the home appliance  100  may receive the commercial AC power AC 1  from the grid  70  via the first power line Pln. On the other hand, during interruption of electric power, the home appliance  100  may receive the DC power DC 1  from the UPS  50  via the third power line Pld. 
         [0022]    As shown in  FIG. 2 , the home appliance  100  may include a driver  245  for driving a load  244 , and a power supply  195  for converting the AC power AC 1 , which is supplied from the outside of the home appliance  100 , while receiving the DC voltage 
         [0023]    DC 1  during interruption of electric power. The home appliance  100  further includes a controller  310  for performing a control operation to supply a first electric power Le 1  to the load  244  based on the AC power AC 1  supplied to the power supply  195  in accordance with a normal operation mode when no interruption of electric power occurs, and a control operation to supply a third electric power Le 3  to the load  244  based on the DC power DC 1  applied to the power supply  195  in accordance with a power saving mode during interruption of electric power. 
         [0024]    In particular, during interruption of electric power, the home appliance  100  supplies second electric power Le 2  based on the applied DC power DC 1  to the load  244  for a first period in accordance with the normal operation mode, and supplies the third electric power Le 3  based on the applied DC power DC 1  for a second period in accordance with the power saving mode. Accordingly, it may be possible to stably supply electric power to the home appliance  100  even when interruption of electric power is lengthened. Such an operation method of the home appliance will be described later in more detail with reference to  FIG. 6 . 
         [0025]      FIGS. 3A to 3F  are views explaining various examples of the home appliance.  FIG. 3A  illustrates a refrigerator  100   a.    FIG. 3  illustrates a washing machine  100   b.    FIG. 3C  illustrates an air conditioner  100   c.    FIG. 3D  illustrates a cooking appliance  100   d.    FIG. 3E  illustrates a cleaner  100   e.    FIG. 3F  illustrates a TV  100   f.  Meanwhile, there may also be various other examples of the home appliance. 
         [0026]    First, the refrigerator  100   a  of  FIG. 3A  will be described in detail. Although not shown, the appearance of the refrigerator  100   a  is approximately defined by a case  110  having an inner space partitioned into a freezing compartment and a refrigerating compartment, a freezing compartment door  120  for closing the freezing compartment, and a refrigerating compartment door  140  for closing the refrigerating compartment. 
         [0027]    Door handles  121  are provided at respective front surfaces of the freezing compartment door  120  and refrigerating compartment door  140 . The door handles  121  protrude forwardly in order to allow the user to easily pivot the freezing compartment door  120  and refrigerating compartment door  140  while grasping the door handles  121 . 
         [0028]    A home bar  810  may be further provided at the front surface of the refrigerating compartment door  140 , as a convenience means for allowing the user to retrieve articles, such as beverages, stored inside of the refrigerating compartment door  140  without opening the refrigerating compartment door  140 . 
         [0029]    A dispenser  160  may also be provided at the front surface of the freezing compartment door  120 , as a convenience means for allowing the user to retrieve ice or drinking water without opening the freezing compartment door  120 . A control panel  200  may further be provided at the front surface of the freezing compartment door  120  above the dispenser  160 . The control panel  200  allows the user to control operation of the refrigerator  100   a,  and displays a state of the refrigerator  100   a  on a screen. 
         [0030]    The control panel  200  may include an input unit  220  including a plurality of buttons, and a display  230  for displaying a control screen, an operation state, etc. The display  230  displays information such as a control screen, operation state, and compartment temperature. For example, the display  230  may display a service type of the dispenser  160  (ice cubes, water, or crushed ice), a set freezing compartment temperature, and a set refrigerating compartment temperature. 
         [0031]    The display  230  may be implemented using various displays such as a liquid crystal display (LCD), a light emitting diode (LED), and an organic light emitting diode (OLED). Alternatively, the display  230  may be implemented using a touchscreen capable of additionally performing the function of the input unit  220 . 
         [0032]    The input unit  220  may include a plurality of operating buttons. For example, the input unit  220  may include a dispenser setting button (not shown) for setting a service type of the dispenser (ice cubes, water, or crushed ice), a freezing compartment temperature setting button (not shown) for setting a freezing compartment temperature, and a refrigerating compartment temperature setting button (not shown) for setting a refrigerating compartment temperature. Meanwhile, the input unit  220  may be implemented using a touchscreen capable of additionally performing the function of the display  230 . 
         [0033]    Meanwhile, the refrigerator associated with the present disclosure is not limited to the double door type illustrated in the drawings, and may be of any type, for example, one door type, sliding door type, or curtain door type, so long as a compressor and a fan are provided for the refrigerating cycle or freezing cycle of the refrigerator. 
         [0034]      FIG. 4  is a view roughly illustrating a configuration of the refrigerator illustrated in  FIG. 3A . 
         [0035]    Referring to  FIG. 4 , the refrigerator  100   a  includes a compressor  112 , a condenser  116  for condensing a refrigerant compressed in the compressor  112 , a refrigerating compartment evaporator  122 , and a freezing compartment evaporator  124 . The refrigerating compartment evaporator  122  and freezing compartment evaporator  124  are disposed in the refrigerating compartment and the freezing compartment, respectively, to evaporate the refrigerant condensed in the condenser  116  after receiving the condensed refrigerant. The refrigerator  100   a  further includes a 3-way valve  130  for supplying the condensed refrigerant from the condenser  116  to the refrigerating compartment evaporator  122  or the freezing compartment evaporator  124 , a refrigerating compartment expansion valve  132  for expanding the refrigerant supplied to the refrigerating compartment evaporator  122 , and a freezing compartment expansion valve  134  for expanding the refrigerant supplied to the freezing compartment evaporator  124 . 
         [0036]    The refrigerator  100   a  may further include a gas-liquid separator for separating the refrigerant emerging from the evaporators  122  and  124  into a gaseous refrigerant and a liquid refrigerant. The refrigerator  100   a  may additionally include a refrigerating compartment fan  142  for sucking cold air emerging from the refrigerating compartment evaporator  122 , and blowing the sucked cold air into the refrigerating compartment, and a freezing compartment fan  144  for sucking cold air emerging from the freezing compartment evaporator  124 , and blowing the sucked cold air into the freezing compartment. 
         [0037]    The refrigerator  100   a  may further include a compressor driver  113  for driving the compressor  112 , a refrigerating compartment fan driver  143  for driving the refrigerating compartment fan  142 , and a freezing compartment fan driver  145  for driving the freezing compartment fan  144 . 
         [0038]    As previously indicated,  FIG. 2  is a block diagram roughly illustrating an inner configuration of the home appliance illustrated in  FIG. 1 . The home appliance  100  includes a power supply  195 , an input unit  220 , a display  230 , a load  144 , a driver  234 , and a controller  310 . The home appliance  100  may further include a communication unit  235 , and an audio output unit. The input unit  220  includes a plurality of operating buttons and, as such, sends an input signal, for example, a freezing compartment setting temperature or a refrigerating compartment setting temperature, to the controller  310 . 
         [0039]    The display  230  may display an operation state of the home appliance  100  or the like. To this end, the display  230  may include an LED, an LCD, or an OLED. The display  230  may display an operation mode upon interruption of electric power. For example, when the operation mode upon interruption of electric power is a normal operation mode based on DC power, the display  230  may display information indicating this operation mode. On the other hand, when the operation mode upon interruption of electric power is a power saving operation mode based on DC power, the display  230  may display information indicating this operation mode. 
         [0040]    When there is no power saving mode input upon interruption of electric power, the display  230  may display a power saving mode recommendation message. Alternatively, the display  230  may output the power saving mode recommendation message through the audio output unit. 
         [0041]    The communication unit  235  may exchange data with an external device through wired or wireless communication. For example, the communication unit  235  may receive information about interruption of electric power, kind and level of backup power supplied upon interruption of electric power, supply duration of the backup power, etc. from an access point (AP) device, the UPS  50 , or a mobile terminal by a power line communication (PLC) system, a wireless fidelity (Wi-Fi) system, a ZigBee system, or the like. 
         [0042]    The load  244  may be divided into an AC load  242  and a DC load  215 . When the home appliance  100  is the refrigerator  100   a,  the AC load  242  may include the compressor  112 , AC load  242 , and freezing compartment fan  144 . In this case, the DC load  215  may include a damper  115 . On the other hand, when the home appliance  100  is the washing machine  100   b  of  FIG. 2B , the AC load  242  may include a washing tube, and the DC load  215  may include a display, etc. 
         [0043]    When the home appliance  100  is the air conditioner  100   c  of  FIG. 2C , the AC load  242  may include a compressor, an indoor fan, an outdoor fan, etc., and the DC load  215  may include a display, etc. On the other hand, when the home appliance  100  is a cooking appliance  100   d  of  FIG. 2D , the AC load  242  may include a magnetron, a microwave generator, or the like, and the DC load  215  may include a display, etc. 
         [0044]    When the home appliance  100  is the cleaner  100   e  of  FIG. 2E , the AC load  242  may include a travel unit, a cleaning unit placed in the travel unit, or the like, and the DC load  215  may include a display, a communication unit, etc. Meanwhile, when the home appliance  100  is the TV  100   f  of  FIG. 2F , the AC load  242  may include a relay or the like, and the DC load  215  may include may include a display, a communication unit, etc. 
         [0045]    The driver  245  drives the load  244  of the home appliance  100 . As described above, the driver  245  drives each load of  FIGS. 3A to 3F . The power supply  195  may receive the commercial AC power AC 1  from the outside in a normal state. On the other hand, during interruption of electric power, the power supply  195  may receive the DC power DC 1  from the UPS  50 . 
         [0046]    Referring to  FIG. 5 , the power supply  195  may include an AC power sensor  407  for sensing the commercial AC power AC 1  supplied from the outside in a normal state, the first converter  410  for converting the commercial AC power AC 1  supplied from the outside into DC power, and the inverter  420  for converting the converted DC power into AC power. When the home appliance is the refrigerator  100   a,  the AC power converted by the inverter  420  may be applied to the refrigerating compartment fan  142 , freezing compartment fan  144 , and compressor  112 , to be used for driving thereof. 
         [0047]    The power supply  195  may further include a DC power sensor  409  for sensing the DC power DC 1  supplied from the external UPS  50  upon interruption of electric power, and the second converter  415  for converting level of the DC power DC 1  supplied from the external UPS  50  upon interruption of electric power. The DC power level-converted by the second converter  415  may be applied to the damper  115 . The DC power level-converted by the second converter  415  may also be applied to the inverter  420 , to be used for driving of the AC load  242  of the load  244 . In addition, the power supply  195  may supply the converted DC power or converted AC power to the AC load  242  and DC load  215  of the load  244 , etc. 
         [0048]    The AC power sensor  407  may detect the commercial AC power AC 1  input from the grid  70 . To this end, the AC power sensor  407  may include a current transformer (CT) to detect an input AC current, a shunt resistor, a voltage transformer (VT) to detect an input AC voltage, etc. The detected input AC current or input AC voltage may be input to the controller  310 , as a discrete pulse signal. The controller  310  may determine whether or not interruption of the commercial AC power AC 1  has occurred, based on the detected input AC current or input AC voltage. 
         [0049]    The DC power sensor  409  may detect the DC power DC 1  input from the UPS  50 . To this end, the DC power sensor  409  may include a current transformer (CT) to detect an input DC current, a shunt resistor, a voltage transformer (VT) to detect an input DC voltage, etc. The detected input DC current or input DC voltage may be input to the controller  310 , as a discrete pulse signal. 
         [0050]    The controller  310  may determine whether or not interruption of the commercial AC power AC 1  has occurred, based on the detected input DC current or input DC voltage. The first converter  410  converts the commercial AC power AC 1  into DC power, and then outputs the converted DC power. 
         [0051]    For example, the first converter  410  may be constituted by a diode, etc. without using a switching element and, as such, may perform a rectification operation without requiring a separate switching operation. Alternatively, the first converter  410  may include a switching element. In this case, the first converter  410  may perform boosting operation, improvement of power factor, and DC power conversion through switching operation of the switching element. 
         [0052]    The second converter  415  may convert level of the DC power DC 1 , and may output the level-converted DC power DC 1 . The second converter  415  may be a DC/DC converter. For example, the second converter  415  may be a buck converter, a boost converter, a buck-boost converter, or a fly-back converter. The inverter  420  includes a plurality of inverter switching elements. In accordance with ON/OFF operations of the inverter switching elements, the inverter  420  may convert DC power received from the first converter  410  or second converter  415  into 3-phase AC power va-vb-vc having a predetermined frequency, and may output the 3-phase AC power va-vb-vc. 
         [0053]    The inverter  420  may have a configuration in which three pairs of arm switching elements are connected in parallel, and each arm switching element pair includes upper and lower arm switching elements connected in series. In accordance with operations of the switching elements in the inverter  420 , the converted AC power may be supplied to the AC load  242  of the load  244 , etc. 
         [0054]    The controller  310  may control various operations of inner constituent elements of the home appliance. For example, the controller  310  may control operation of the driver  254 , etc. Meanwhile, in accordance with an embodiment of the present disclosure, the controller  310  may perform a control operation to supply first electric power Le 1  based on the applied AC power AC 1  to the load  244  in accordance with a normal operation mode in a state in which no interruption of electric power occurs, may perform a control operation to supply second electric power Le 2  based on the applied DC power DC 1  to the load  244  in accordance with the normal operation mode during interruption of electric power, and may perform a control operation to supply third electric power Le 3  based on the applied DC power DC 1  to the load  244  in accordance with a power saving mode during interruption of electric power. The controller  310  may perform a control operation to output a power saving mode recommendation message when there is no power saving mode input upon interruption of electric power. 
         [0055]    During interruption of electric power, the controller  310  may perform a control operation to supply the second electric power Le 2  based on the applied DC power DC 1  to the load  244  for a first period in accordance with the normal operation mode, and may perform a control operation to supply the third electric power Le 3  based on the applied DC power DC 1  to the load  244  for a second period in accordance with the power saving mode in response to a power saving mode input. In this case, the first electric power Le 1  may have a higher level than the second electric power Le 2 , and the third electric power Le 3  may have a lower level than the second electric power Le 2 . 
         [0056]    The controller  310  may determine whether or not interruption of electric power has occurred, based on level of the AC power AC 1  sensed by an AC power sensor to sense level of the AC power AC 1  or based on level of the DC power DC 1  sensed by a DC power sensor to sense level of the DC power DC 1 . The controller  310  may vary at least one of the second electric power Le 2  and third electric power Le 3  in accordance with the sensed level of the DC power DC 1 . The controller  310  may restrict operation of the driver  245  or vary operation modes in accordance with the sensed level of the DC power DC 1 . 
         [0057]    The controller  310  may also perform a control operation to activate only a part of the various buttons of the input unit  220 , namely, buttons associated with the power saving mode and a power button, upon interruption of electric power. For example, a power saving mode button may be activated upon interruption of electric power to induce operation thereof. When the power saving mode operates during interruption of electric power, only a power saving mode release button may be activated, and other buttons may be deactivated. 
         [0058]    The controller  310  may also perform a control operation to vary operation mode or operation time of the home appliance  100  upon interruption of electric power based on information about interruption of electric power, kind and level of backup power supplied upon interruption of electric power, supply duration of the backup power, etc. The controller  310  may perform a control operation to achieve a customized operation. 
         [0059]    The audio output unit may convert an electrical signal from the controller  170  into an audio signal, and then output the audio signal. To this end, the audio output unit may include a speaker or the like. The audio output unit may output a power saving mode recommendation message for execution of the power saving mode upon interruption of electric power. 
         [0060]      FIG. 6  is a flowchart illustrating an operating method of the home appliance according to an embodiment of the present disclosure.  FIGS. 7 and 8  are views explaining the operating method of  FIG. 6 . 
         [0061]    Referring to  FIG. 6 , the controller  310  first determines whether or not interruption of electric power has occurred (S 610 ). For example, the controller  310  may determine whether or not interruption of electric power has occurred, based on level of the AC power AC 1  sensed by the AC power sensor  407  or level of the DC power DC 1  sensed by the DC power sensor  409 . 
         [0062]    When the level of the AC power AC 1  sensed by the AC power sensor  407  is equal to or lower than a predetermined first level, the controller  310  may determine that interruption of electric power has occurred. Alternatively, when the level of the DC power DC 1  sensed by the DC power sensor  409  is equal to or lower than a predetermined second level, the controller  310  may determine that interruption of electric power has occurred. 
         [0063]    When it is not determined that interruption of electric power has occurred, the controller  310  controls the home appliance  100  to operate normally (S 613 ). The controller  310  of the home appliance  100  controls the home appliance  100  to operate normally based on the commercial AC power AC 1  supplied to the home appliance  100 . In detail, the controller  310  executes a control operation to supply first electric power Le 1  to the load  244  based on the applied AC power AC 1 . 
         [0064]    On the other hand, when it is determined that interruption of electric power has occurred, step S 615  is executed. The controller  310  of the home appliance  100  determines whether or not the DC power DC 1  is supplied (S 615 ). For example, the controller  310  may not only determine that interruption of electric power has occurred, but may also determine that the DC power DC 1  is supplied, when the level of the DC power DC 1  sensed by the DC power sensor  409  is equal to or higher than the predetermined second level. 
         [0065]    When the DC power DC 1  is supplied, the controller  310  of the home appliance  100  controls the home appliance  100  to operate based on the supplied DC power DC 1  (S 620 ). The controller  310  of the home appliance  100  may perform a control operation to supply the second electric power Le 2  based on the DC power DC 1  to the load  244  in accordance with the normal operation mode. In this case, the second electric power Le 2  in the normal operation mode may be lower than the first electric power Le 1  before interruption of electric power. 
         [0066]    The controller  310  of the home appliance  100  may also determine whether or not a power saving mode input has been received (S 625 ). When it is determined that a power saving mode input has been received, the controller  310  controls the home appliance  100  to operate in the power saving mode (S 630 ). On the other hand, when it is not determined that a power saving mode input has been received, the controller  310  may perform a control operation to output a power saving mode recommendation message while controlling the home appliance  100  to operate normally (S 635 ). 
         [0067]    For example, when a power saving mode button  220   a  ( FIG. 8 ) in the input unit  220  operates upon interruption of electric power, the controller  310  of the home appliance  100  controls the home appliance  100  to operate in the power saving mode. The controller  310  of the home appliance  100  performs a control operation to supply the third electric power Le 3  to the load  244  based on the applied DC power DC 1  in accordance with the power saving mode during interruption of electric power. In this case, the third electric power Le 3  in the power saving mode operation may be lower than the second electric power Le 2  according to the normal operation during interruption of electric power. 
         [0068]    Hereinafter, examples of the power saving mode in various home appliances will be described. For example, when the home appliance  100  is the refrigerator  100   a,  in the power saving mode, driving time of the compressor  112  may be reduced, or cooling capacity may be supplied using a cold storage medium disposed in the refrigerator  100   a.  When the home appliance  100  is the washing machine  100   b,  in the power saving mode, operation time or frequency of one of washing, rinsing, and spin-drying may be reduced, drying time may be reduced, abrupt speed change of the motor in a forward or backward rotation direction may be restricted, or a heater function may be restricted. 
         [0069]    When the home appliance  100  is the air conditioner  100   c  target cooling temperature may be raised, driving time of the compressor  112  may be reduced, and/or operations associated with buttons other than the button associated with the power saving mode may be restricted in the power saving mode. When the home appliance  100  is the cooking appliance  100   d  output power of a microwave may be reduced and/or operation time may be reduced in the power saving mode. 
         [0070]    When the home appliance  100  is the cleaner  100   e  travel distance may be reduced, driving time and/or rotation speed of the fan motor in the cleaning unit may be reduced in the power saving mode. When the home appliance  100  is the TV  100   f,  luminance of the display to display an image may be lowered, or audio volume of the audio output unit may be lowered. 
         [0071]    When the home appliance  100  is a dehumidifier performance of other functions than a dehumidifying function, for example, an air cleaning function, may be restricted in the power saving mode. When the home appliance  100  is a dryer a message informing of requirement to clean a duct and a filter may be output because power consumption of the duct and filter is excessive in the power saving mode. 
         [0072]    In accordance with the power saving mode upon interruption of electric power, it may be possible to reduce power consumption of the home appliance  100 , and hence, consumption of DC power supplied from the UPS  50  may be reduced. Accordingly, it may be possible to use DC power for a longer period of time. When the 
         [0073]    UPS  50  is provided with a battery, the home appliance  100  may be stably driven for a lengthened period of time. 
         [0074]    The controller  310  may vary at least one of the second electric power Le 2  and third electric power Le 3  in accordance with the level of the DC power DC 1  sensed upon interruption of electric power. In response to the power saving mode input, the controller  310  may perform a control operation to lower the third electric power Le 3  as the sensed level of the DC power DC 1  is lowered. 
         [0075]    The controller  310  may also restrict operation of the driver  245  or vary the operation mode in response to the power saving mode input. The controller  310  may restrict operation of the driver  245  or vary the operation mode in accordance with the level of the DC power DC 1  sensed upon interruption of electric power. 
         [0076]    When it is determined at step S 625  that there is no power saving mode input for a predetermined time, the controller  310  may perform a control operation to output a power saving mode recommendation message while controlling the home appliance  100  to operate normally. The power saving mode recommendation message may be output through the display  230  or the audio output unit. 
         [0077]      FIG. 7  illustrates an example of the operating method of the home appliance before and after interruption of electric power. The time Tx indicates a time when interruption of electric power occurs. The period before the time Tx is a period in which a first mode, e.g., a normal operation mode, is executed. On the other hand, the period after the time Tx is a period in which a second mode, e.g., an operation mode upon interruption of electric power, is executed. The operation mode upon interruption of electric power, e.g., a power-interruption-based operation mode, may be divided into a normal operation mode based on DC power and a power saving operation mode. 
         [0078]    When the home appliance  100  operates in the first mode, the first electric power Le 1  based on the commercial AC power AC 1  may be supplied to the load  244 . When interruption of electric power occurs at the time Tx, supply of the commercial AC power AC 1  to the home appliance  100  may be interrupted at the time Tx, and the DC power DC 1  from the UPS  50  may be supplied to the home appliance  100 . 
         [0079]    In this case, the home appliance  100  may operate in the second mode from the time Tx. When the home appliance  100  operates in the second mode, the second electric power Le 2  based on the applied DC power DC 1  may be supplied to the load  244  for a first period Pe 1 . The second electric power Le 2  may be lower than the first electric power Le 1 . 
         [0080]    The controller  310  may perform a control operation to output a power saving mode recommendation message for the first period Pe 1 . When the power saving mode button  220   a  ( FIG. 8 ) is pressed at a time Ty, the power saving mode may be executed. The third electric power Le 3  based on the DC power DC 1  may be supplied to the load  244  for a second period Pe 2 . In this case, the third electric power Le 3  may be lower than the second electric power Le 2 . As consumption of electric power applied to the load is reduced in accordance with the power saving mode executed upon interruption of electric power, it may be possible to stably operate the home appliance for a lengthened period of time during interruption of electric power. 
         [0081]    The display  230  may display the operation mode upon interruption of electric power or may display power consumption during interruption of electric power. The display  230  may also individually display the first period and the second period.  FIG. 8  illustrates display of operation mode information of the home appliance on the display  230 . 
         [0082]      FIG. 8(   a ) illustrates that the display  230  displays information  810  indicating a state in which the home appliance  100  operates normally by the commercial AC power AC 1  in a normal mode, namely, the first mode, under the condition that no interruption of electric power occurs. 
         [0083]      FIG. 8(   b ) illustrates that the display  230  displays information  815  indicating a state in which the home appliance  100  operates normally based on the DC power DC 1  in the second mode during interruption of electric power. A power saving mode recommendation message  817  may also be displayed on the display  230 . When the user presses the power saving mode button  220   a  after seeing the message  817 , the home appliance  100  may enter the power saving mode. 
         [0084]      FIG. 8(   c ) illustrates that the display  230  displays information  820  indicating a state in which the home appliance  100  operates in the power saving mode based on the DC power DC 1  during interruption of electric power. Accordingly, the user may immediately recognize the power saving mode operation upon interruption of electric power. 
         [0085]      FIG. 9  illustrates supply of electric power to a home appliance according to another embodiment of the present disclosure. A power supply system  20  is illustrated. The power supply system  20  may include a home appliance  100   k  and a grid  70 . The case of  FIG. 9  differs from the case of  FIG. 1  in that the UPS  50  is omitted, and the home appliance  100   k  further includes a battery  199 . The following description will be given mainly in conjunction with the differences. 
         [0086]    When no interruption of electric power occurs, the commercial AC power AC 1  from the grid  70  is supplied to the home appliance  100   k  via a first line Pln. Using the commercial AC power AC 1 , the home appliance  100   k  supplies the first electric power Le 1  to the load  244  therein. The home appliance  100   k  may store the DC power DC 1  in the battery  199 , using the commercial AC power AC 1 . 
         [0087]    The home appliance  100   k  may sense whether interruption of electric power has occurred, based on the AC power AC 1  sensed by the AC power sensor  407 , and may supply electric power based on the DC power DC 1  stored in the battery  199  to the load  244  during interruption of electric power. In particular, when a power saving mode input is received, the third electric power Le 3  may be supplied to the load  244 . The second electric power Le 2  may be supplied to the load  244  when no power saving mode input is received. The home appliance  100   k  of  FIG. 9  may omit the DC power sensor  409  of  FIG. 5 . 
         [0088]      FIG. 10  illustrates supply of electric power to a home appliance according to another embodiment of the present disclosure. A power supply system  20  is illustrated, which may include a home appliance  100   k,  a grid  70 , and a UPS  50 . The UPS  50  differs from that of  FIG. 1  in that the UPS  50  does not supply the DC power DC 1 , but supplies second AC power AC 2 , and the home appliance  100   k  further includes a battery  199 . The following description will be given mainly in conjunction with such differences. 
         [0089]    When no interruption of electric power occurs, the commercial AC power AC 1  from the grid  70  is applied to the home appliance  100   k  via a first line Pln. Using the commercial AC power AC 1 , the home appliance  100   k  supplies the first electric power Le 1  to the load  244  therein. The home appliance  100   k  may also store the DC power DC 1  in the battery  199  using the commercial AC power AC 1 . 
         [0090]    During interruption of electric power, the UPS  50  supplies the second AC power AC 2  to the first power line Pln via a line PLu. The home appliance  100   k  may store the DC power DC 1  to the battery  199  during interruption of electric power using the second AC power AC 2 . 
         [0091]    The home appliance  100   k  may supply electric power based on the DC power DC 1  stored in the battery  199  to the load  244  during interruption of electric power. In particular, when a power saving mode input is received, the third electric power Le 3  may be supplied to the load  244 . On the other hand, the second electric power Le 2  may be supplied to the load  244  when no power saving mode input is received. The home appliance  100   k  of  FIG. 10  may omit the DC power sensor  409  of  FIG. 5 . 
         [0092]      FIG. 11  is a flowchart illustrating an operating method of the home appliance according to another embodiment of the present disclosure.  FIGS. 12A to 12E  are views explaining the operating method of  FIG. 11 . The controller  310  of the home appliance first determines whether or not interruption of electric power has occurred (S 1110 ). The controller  310  may determine whether or not interruption of electric power has occurred, based on level of the AC power AC 1  sensed by the AC power sensor  407  or level of the DC power DC 1  sensed by the DC power sensor  409 . 
         [0093]    When the level of the AC power AC 1  sensed by the AC power sensor  407  is equal to or lower than a predetermined first level, the controller  310  may determine that interruption of electric power has occurred. Alternatively, when the level of the DC power DC 1  sensed by the DC power sensor  409  is equal to or lower than a predetermined second level, the controller  310  may determine that interruption of electric power has occurred. 
         [0094]    When determined that interruption of electric power has not occurred, the controller  310  controls the home appliance  100  to operate normally (S 1113 ). The controller  310  of the home appliance  100  controls the home appliance  100  to operate normally based on the commercial AC power AC 1  supplied to the home appliance  100 . The controller  310  executes a control operation to supply the first electric power Le 1  to the load  244  based on the applied AC power AC 1 . 
         [0095]    When it is determined that interruption of electric power has occurred, step S 1115  is executed. The controller  310  of the home appliance  100  determines whether or not backup power is supplied (S 1115 ). The backup power may be the above-described DC power. The following description will be given in conjunction with the case in which the backup power is the DC power. 
         [0096]    For example, the controller  310  may not only determine that interruption of electric power has occurred, but may also determine that the DC power DC 1  is supplied when the level of the DC power DC 1  sensed by the DC power sensor  409  is equal to or higher than a predetermined second level. When the DC power DC 1  is supplied, the controller  310  of the home appliance  100  controls the home appliance  100  to operate based on the supplied DC power DC 1  (S 1120 ). 
         [0097]    The controller  310  of the home appliance  100  may perform a control operation to supply the second electric power Le 2  based on the DC power DC 1  to the load  244  in accordance with the normal operation mode. In this case, the second electric power Le 2  in the normal operation mode may be lower than the first electric power Le 1  before interruption of electric power. 
         [0098]    When the home appliance  100  operates based on backup power, namely, the DC power, the controller  310  of the home appliance  100  performs a control operation to output a message indicating an operation based on the backup power or an operation restriction request message to the display  230  (S 1123 ). 
         [0099]      FIG. 12A  illustrates simultaneous display of a message  1210  indicating an operation based on the backup power and an operation restriction request message  1212  on the display  230 . Alternatively, the message  1210  and the message  1212  may be sequentially displayed. 
         [0100]    The controller  310  of the home appliance  100  determines whether or not a power saving mode input has been received (S 1125 ). When it is determined that a power saving mode input has been received, the controller  310  controls the home appliance  100  to operate in the power saving mode (S 1130 ). When it is not determined that a power saving mode input has been received, the controller  310  may perform a control operation to output a power saving mode recommendation message while controlling the home appliance  100  to operate normally (S 1135 ). 
         [0101]    For example, when a power saving mode button  220   a  ( FIG. 8 ) in the input unit  220  operates upon interruption of electric power, the controller  310  of the home appliance  100  controls the home appliance  100  to operate in the power saving mode. Examples of the power saving mode in various home appliances will be described. 
         [0102]    In one example, when the home appliance  100  is a dehumidifier, in the power saving mode, the home appliance  100  may operate in a minimal dehumidification mode settable by the user or in a minimal dehumidification mode taking into consideration temperature and humidity of ambient air. In addition, an air cleaning function may be restricted. 
         [0103]    In another example, when the home appliance  100  is the air conditioner  100   c,  the home appliance  100  may operate in a minimal cold capacity mode settable by the user and/or in a minimal cold capacity mode taking into consideration temperature and humidity of ambient air. In addition, a power cooling function and a strong blowing function may be restricted. 
         [0104]    In another example, when the home appliance  100  is the washing machine  100   b,  the function of the heater to heat water when cold water is supplied may be restricted, respective times of washing courses may be reduced, and/or abrupt rotation variation of the motor in a forward or backward rotation direction may be reduced to reduce power consumption of the motor. In the case of a top load washing machine including an upwardly opened washing tub, rotation of a pulsator may be restricted under the condition that tub washing is executed. 
         [0105]    In another example, when the home appliance  100  is a dryer, a message informing of requirement to clean a duct and a filter may be output in order to reduce power consumption. In addition, a drying function using hot air may be restricted and, in place thereof, a blowing function may be executed. Alternatively, after the drying function using hot air is executed for a predetermined time, a message informing of stoppage of the drying function may be output, and the drying function may be stopped in order to reduce execution time. 
         [0106]    In another example, when the home appliance  100  is the cleaner  100   e,  a message informing of requirements to empty a dust box and to clean a filter may be output during operation of the home appliance  100  in order to reduce power consumption. In addition, a high power function such as a strong suction function may be restricted. Alternatively, after the high power function is executed for a predetermined time, a message informing of stoppage of the high power function may be output, and the high power function may be stopped, in order to reduce execution time. 
         [0107]    In still another example, when the home appliance  100  is a water purifier, heating temperature for supply of hot water may be lowered, cooling temperature for supply of cold water may be raised, or functions such as fast heating and fast cooling may be restricted. 
         [0108]    In accordance with the power saving mode executed during interruption of electric power, it may be possible to reduce power consumption of the home appliance and as such, consumption of the DC power supplied from the UPS  50  may be reduced. Accordingly, it may be possible to use the DC power for a longer period of time. When the UPS  50  is provided with a battery, the home appliance  100  may be stably driven for a lengthened period of time. 
         [0109]    During interruption of electric power, the controller  310  may restrict operation of the driver or vary the operation mode in accordance with the level of the DC power DC 1  sensed during interruption of electric power while operating in the power saving mode. 
         [0110]    When it is determined at step S 1125  that there is no power saving mode input for a predetermined time, the controller  310  may perform a control operation to output a power saving mode recommendation message while controlling the home appliance  100  to operate normally. The power saving mode recommendation message may be output through the display  230  or the audio output unit. 
         [0111]    After the home appliance  100  enters the power saving mode at step S 1130 , the controller  310  may perform a control operation to output a power saving mode releasable message (S 1137 ).  FIG. 12C  illustrates display of a message  1220  indicating a power saving mode operation and a message  1224  indicating restriction of operations of buttons other than the power saving mode release button. 
         [0112]    When the display  230  is implemented using a touchscreen, it may be possible to further display a power saving mode release button  1225  on the display  230 . In this case, the user may release the power saving mode by pressing the power saving mode release button  1225 . 
         [0113]    The controller  310  determines whether or not a power saving mode release input has been received (S 1144 ). When it is determined that a power saving mode release input has been received, the controller  310  controls the home appliance  100  to operate in the normal operation mode (S 1146 ). The controller  310  may control the driver to operate in the normal operation mode based on the DC power. 
         [0114]    When the power saving mode is released, the controller  310  may perform a control operation to display a power saving mode release message  1230  and a normal operation mode message  1232 . The controller  310  may also perform a control operation to display information  1234  as to an operation duration based on the backup power, namely, the DC power. Accordingly, it may be possible to enhance user convenience. 
         [0115]    When the power saving mode is released in a state in which the DC power from the battery of the UPS  50  is supplied, the controller  310  may perform a control operation to display information  1236  as to a remaining level of the battery on the display  230 . In this case, the home appliance  100  may periodically receive the remaining battery level information, and user convenience may be enhanced. 
         [0116]    In addition to the remaining battery level information  1236 , the power saving mode release message  1230  and normal operation mode message  1232  may be displayed. The information  1234  as to an operation duration based on the DC power may also be displayed. 
         [0117]    The controller  310  may also determine whether or not interruption of electric power has been released (S 1142 ). When it is determined that interruption of electric power has been released, the controller  310  performs a control operation to operate the home appliance  100  in the normal operation mode based on the AC power, as at step S 1113 . When the AC power sensor  407  senses inputting of the commercial AC power, the controller  310  may determine that interruption of electric power has been released. 
         [0118]    Although  FIGS. 12A to 12E  illustrate display of various messages on the display, such messages may be output in the form of audio through the audio output unit. 
         [0119]    The home appliance and operating method thereof according to the present disclosure can be realized as code, which can be written on a recording medium that can be read by a processor equipped in the home appliance and can be read by a processor. The recording medium that can be read by a processor includes various kinds of recording media, on which data that can be read by a processor is written, such as a read only memory (ROM), a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage, and a carrier wave type (e.g., transmission over the Internet). The recording medium that can be read by a processor can be distributed to computer systems connected to one another on a network, and code that can be read by a processor can be stored in the recording medium in a distributed manner and executed. 
         [0120]    As apparent from the above description, the home appliance according to each of the above-described embodiments of the present disclosure may simply inform of an operation mode upon interruption of electric power in accordance with a configuration including a driver to drive a load, a power supply to convert AC power supplied from an outside of the home appliance, and to receive backup power during interruption of electric power, a display, and a controller to perform a control operation to operate the home appliance based on the backup power and to output a message informing of the operation based on the backup power or an operation restriction request message to the display, upon interruption of electric power. 
         [0121]    A control operation is performed to output a power saving mode releasable message to the display during operation in the power saving mode in response to a power saving mode input upon interruption of electric power and, as such, user convenience may be enhanced. 
         [0122]    Operations of buttons other than the power saving mode button or power saving mode release button are restricted during operation in the power saving mode and, as such, the operation in the power saving mode may be stably executed. 
         [0123]    It may also be possible to restrict operation of the driver or to vary operation mode during operation in the power saving mode in accordance with the sensed level of the backup power and, as such, power consumption may be reduced. 
         [0124]    Any reference in this specification to “one embodiment,” “an embodiment,” “example embodiment,” etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the disclosure. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with any embodiment, it is submitted that it is within the purview of one skilled in the art to effect such feature, structure, or characteristic in connection with other ones of the embodiments. 
         [0125]    Although embodiments have been described with reference to a number of illustrative embodiments thereof, it should be understood that numerous other modifications and embodiments can be devised by those skilled in the art that will fall within the spirit and scope of the principles of this disclosure. More particularly, various variations and modifications are possible in the component parts and/or arrangements of the subject combination arrangement within the scope of the disclosure, the drawings and the appended claims. In addition to variations and modifications in the component parts and/or arrangements, alternative uses will also be apparent to those skilled in the art.