Patent Publication Number: US-2023134292-A1

Title: Home appliance and refrigerator

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority under 35 U.S.C. 119 and 35 U.S.C. 365 to Korean Patent Application No. 10-2021-0146677, filed on Oct. 29, 2021, which is hereby incorporated by reference in its entirety. 
     TECHNICAL FIELD 
     The present disclosure relates to a home appliance and a refrigerator. 
     BACKGROUND 
     In general, a refrigerator is a home appliance for storing foods in an internal storage space, which is shield by a refrigerator door, at a low temperature by low temperature air. The refrigerator cools the inside of the storage space using cool air generated by heat-exchanging with a refrigerant that circulates a cooling cycle to store the foods in an optimum state. 
     Such refrigerators tend to increase more and more in size and provide multi-functions due to the trends of change of dietary life and high quality, and accordingly, refrigerators provided with various structures and convenience devices in consideration of user convenience are brought to the market. 
     In order to harmonize with an environment in which the refrigerator is disposed or with surrounding furniture or home appliances, technologies structures for varying an outer appearance of a door front of the refrigerator are developed, and this trend is the same throughout the home appliance. 
     U.S. Pat. No. 8,789,900 (Cited Reference 1) discloses a structure in which a decoration panel forming an outer appearance is installed on a door front of a refrigerator, and here, the outer appearance of the door front is formed according to a user&#39;s preference by detachably configuring the decoration panel. 
     However, the refrigerator of the Cited Reference 1 has a problem in that, when a user wants to change the outer appearance, the entire decoration panel needs to be removed and replaced, and it is not possible to use the decoration panel before replacement any longer. 
     To solve this limitation, Chinese Patent Application No. 103250018 (Cited Reference 2) discloses a refrigerator in which a reflective layer and a transparent panel are disposed on a door front and colored light emitting members are mounted on both side ends of the reflective layer to cause the transparent panel to glow with set color. 
     However, in the Cited Reference 2, since the light emitting member is disposed further inside the panel defining the front surface of the door, shadows are generated at both ends of the door during an operation of the light emitting member to cause a poor outer appearance. 
     Korean Patent Publication No. 10-0820355 (Cited Reference 3) discloses an LED driving device considering external illuminance. 
     Cited Reference 3 discloses a technology for measuring an illuminance value by detecting the intensity of external light in an illuminance sensor, and controlling the brightness of light emitted from an LED panel according to the measured illuminance value. 
     However, Cited Reference 3 discloses a technology for controlling the brightness of light using only the illuminance value without considering a relationship with a user. 
     SUMMARY 
     The present embodiment provides a refrigerator and a home appliance for changing the state of the refrigerator and changing a reference distance for detecting a user based on a detected illuminance value when the user approaches the refrigerator within the reference distance. 
     Optionally or additionally, the present embodiment provides a refrigerator and a home appliance for varying a door for generating light among a plurality of doors according to an illuminance. 
     Optionally or additionally, the present embodiment provides a refrigerator and a home appliance for controlling a light source according to an illuminance and a current time. 
     According to an aspect, a home appliance may include a cabinet having a space, and a door configured to open and dose the space. 
     The door may include a light source. 
     The home appliance may include an illuminance sensor provided in the cabinet or the door and configured to detect illuminance. 
     The home appliance may further include a user detection sensor provided in the cabinet or the door and configured to detect user proximity. 
     The home appliance may further include a controller configured to control the light source based on information detected by the user detection sensor. 
     The light source may include a plurality of LEDs. 
     When a user is detected to approach the home appliance within a reference distance by the user detection sensor, the controller may control the light source of the door to be changed from a first state to a second state. 
     The reference distance may be set to be changeable based on one or more of an illuminance and current time detected by the illuminance sensor. 
     When an illuminance value detected by the illuminance sensor is equal to or greater than a reference illuminance value, the reference distance may be set to a first reference distance. 
     When the illuminance value detected by the illuminance sensor is less than the reference illuminance value, the reference distance may be set to a second reference distance longer than the first reference distance. 
     The reference illuminance value may be manually set in the home appliance, or may be set in a remote device, The reference illuminance value may be received from the remote device through a communicator, and may be stored in a memory of the home appliance. 
     When the current time satisfies a first time range, the reference distance may be set to a first reference distance. When the current time satisfies a second time range, the reference distance may be set to a longer second reference distance than the first reference distance. 
     The controller may determine an operation mode of the home appliance based on a current time and an illuminance detected by the illuminance sensor. 
     When the current time satisfies a first time range and a detected illuminance value satisfies a first illuminance range, the controller may set an operation mode of the home appliance to a first operation mode, 
     When the current time satisfies the first time range and the detected illuminance value satisfies a second illuminance range, the controller may set the operation mode of the home appliance to a second operation mode. 
     Brightness of light emitted from the light source when the light source is turned on in the first operation mode may be set to a first value. Brightness of light emitted from the light source when the light source is turned on in the second operation mode may be set to a second value. 
     A number of LEDs that are turned on in the first operation mode may be set to a first number. A number of LEDs that are turned on in the second operation mode may be set to a second number. 
     An illuminance value of the second illuminance range may be smaller than an illuminance value of the first illuminance range. The second value may be smaller than the first value, and the second number is smaller than the first number. 
     When a current time satisfies a second time range and a detected illuminance value satisfies the first illuminance range, the controller may set an operation mode of the home appliance to a third operation mode. 
     When the current time satisfies the second time range and the detected illuminance value satisfies the second illuminance range, the controller may set the operation mode of the home appliance to a fourth operation mode. 
     Brightness of light emitted from the light source when the light source is turned on in the first operation mode may be set to a third value. Brightness of light emitted from the light source when the light source is turned on in the fourth operation mode may be set to a fourth value. 
     A number of LEDs that are turned on in the third operation mode may be set to a third number. A number of LEDs that are turned on in the fourth operation mode may be set to a fourth number. 
     The third value may be equal to or smaller than the first value. The fourth value may be smaller than the second value and the third value. 
     The third number may be equal to or smaller than the first number. 
     The fourth number may be smaller than the second number and the third number. 
     A number of LEDs that are turned on or brightness of light emitted from a light source that is turned on may be manually set in a home appliance, or may be set in a remote device, may be received from the remote device through a communicator, and may be stored in a memory of the home appliance. 
     The door may include a plurality of doors. 
     When the current time satisfies the first time range or the detected illuminance value satisfies the first illuminance range, if a user is detected to approach the home appliance within a first reference distance by the user detection sensor, the controller may control the light source of each of the plurality of doors to be changed from a first state to a second state. 
     After the light source is changed from the first state to the second state, when the user is not detected to approach the home appliance within the first reference distance by the user detection sensor, a state of the light source may be changed to a previous state. 
     When the current time satisfies the second time range or the detected illuminance value satisfies the second illuminance range, if a user is detected to approach the home appliance within a second reference distance by the user detection sensor, the controller may control the light source of some of the plurality of doors to be changed from a first state to a second state. 
     After the light source of some of the plurality of doors is changed from the first state to the second state, when the user is detected to approach the home appliance within a smaller third reference distance than the second reference distance by the user detection sensor, the controller may control the light source of remaining doors of the plurality of doors to be changed from the first state to the second state. 
     The plurality of doors may include an upper door and a lower door, and the some doors may be lower doors and remaining doors are upper doors. 
     After the light source of each of the plurality of doors is changed from the first state to the second state, when the user is detected to be farther away from the home appliance than the second reference distance by the user detection sensor, a state of the light source may be changed to a previous state. 
     The home appliance may further include a motion sensor configured to detect a movement of an object on a floor on which the cabinet is placed. 
     In a state in which an illuminance value detected by the illuminance sensor is less than a reference illuminance value, when a movement of more than a set number of times is detected by the motion sensor, the controller may control the light source to be changed from the first state to a second state for a set time. 
     The first state may be an off state of the light source, and the second state may be an on state of the light source. 
     The first state may be a state in which the light source is turned on to emit light with first color. The second state may be a state in which the light source is turned on to emit light with second color. 
     According to another aspect, a refrigerator may include a cabinet having a storage room, a plurality of doors configured to open and close the storage room, at least one of the doors including a light source, an illuminance sensor configured to detect illuminance, a user detection sensor configured to detect user proximity, and a controller configured to control the light source based on information detected by the user detection sensor. 
     When a user is detected to approach the refrigerator within a reference distance by the user detection sensor, the controller may control the light source of one or more of the plurality of doors to be changed from a first state to a second state. 
     The reference distance may be set to be changeable based on an illuminance detected by the illuminance sensor. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a front view of a refrigerator according to an embodiment of the present disclosure. 
         FIG.  2    is a perspective view of a refrigerator door according to an embodiment present disclosure. 
         FIG.  3    is a view illustrating a state in which a panel assembly is separated from the refrigerator door. 
         FIG.  4    is a cross-sectional view taken along line  4 - 4  of  FIG.  3   . 
         FIG.  5    is a view illustrating arrangement of a light guide plate and a light source. 
         FIG.  6    is a vertical cross-sectional view showing a light emitting state of the panel assembly. 
         FIG.  7    is a block diagram illustrating a flow of a control signal of the refrigerator. 
         FIG.  8    is a view illustrating a state in which all doors glow in a refrigerator. 
         FIG.  9    is a view illustrating a state in which some doors of a plurality of doors glow. 
         FIG.  10    is a flowchart for explaining a control method of differently setting a reference distance according to illuminance according to the present embodiment. 
         FIG.  11    is a flowchart for explaining a method of setting an operation mode according to illuminance and current time according to the present embodiment. 
         FIG.  12    is a flowchart for explaining a method of controlling a refrigerator during an operation in a first operation mode or a second operation mode. 
         FIG.  13    is a flowchart for explaining a method of controlling a refrigerator during an operation in a third operation mode or a fourth operation mode. 
         FIG.  14    is a diagram for explaining a method of controlling a refrigerator according to motion detection of a motion sensor when the refrigerator operates in the third operation mode or the fourth operation mode. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, detailed embodiments will be described in detail with reference to the accompanying drawings. However, the present disclosure is limited to the embodiments in which the spirit of the present disclosure is proposed, and other degenerate idea or other embodiments included in the scope of the present disclosure may be easily proposed by addition, changes, deletions, etc. of other elements. 
     Hereinafter, a refrigerator will be described as an example of a home appliance, but the description of the refrigerator according to the present disclosure may be applied to various home appliances including a cabinet having a space therein and a door configured to open and close the space The home appliance may include, for example, an air conditioner, a clothes manager, a washing machine, a dryer, a dish washing machine, a cooking appliance, and the like. 
     Furthermore, a home appliance according to the present disclosure is not limited to a home appliance in which an inner space of a cabinet is opened and closed, and it is to be noted that the home appliance according to the present disclosure is also applicable to a home appliance in which an inner space of a cabinet is not opened and dosed. 
     Prior to a description, directions are defined. In an embodiment of the present disclosure, a direction toward a door is defined as a front direction with respect to a cabinet shown in  FIGS.  1  and  2   , a direction toward the cabinet with respect to the door is defined as a rear direction, a direction toward a bottom on which a refrigerator is installed is defined as a downward direction, and a direction away from the bottom is defined as an upward direction. 
       FIG.  1    is a perspective view of a refrigerator according to an embodiment. 
     Referring to  FIGS.  1   , a refrigerator  1  according to an embodiment of the present disclosure may include a cabinet  10  defining a storage space (or storage section) and a door  20  for opening and dosing the storage space of the cabinet  10 . 
     For example, the cabinet  10  may form the storage space partitioned in a vertical direction, a refrigerating compartment may be formed at an upper portion, and a freezing compartment may be formed at a lower portion. The refrigerating compartment may be referred to as an upper storage space, and the freezing compartment may be referred to as a lower storage space. 
     The door  20  may open and close each of the refrigerating compartment and the freezing compartment. For example, the door  20  may be rotatably mounted on the cabinet  10 , and the refrigerating compartment and the freezing compartment may each be opened and closed by rotation. Alternatively, the door  20  may be configured to open and close the refrigerating compartment and/or the freezing compartment by being drawn in and out. 
     The door  20  may include a refrigerating compartment door  201  for opening and closing the refrigerating compartment and a freezing compartment door  202  for opening and closing the freezing compartment. The refrigerating compartment door  201  may be referred to as an upper door, and the freezing compartment door  202  may be referred to as a lower door. 
     The refrigerating compartment door  201  may include a pair of a left refrigerating compartment door and a right refrigerating compartment door that are arranged side by side. The left refrigerating compartment door and the right refrigerating compartment door may open and close the refrigerating compartment while being independently rotated. The left refrigerating compartment door and the right refrigerating compartment door may be disposed adjacent to each other and may have the same size. 
     The freezing compartment door  202  may include a pair of a left freezing compartment door and a right freezing compartment door that are arranged side by side. The left freezing compartment door and the right freezing compartment door may open and close the freezing compartment while being independently rotated. The left freezing compartment door and the right freezing compartment door may be disposed adjacent to each other and may have the same size. 
     Needless to say, although a refrigerator having a structure in which the refrigerating compartment is defined above the freezing compartment is described as an example in this embodiment, the present disclosure may be applied to all types of refrigerators equipped with a door without being limited to a type of a refrigerator. 
     An outer appearance of the front surface of the refrigerator  1  may be formed in the state in which the door  20  is closed and may form the out appearance of the refrigerator  1  viewed from the front in the state in which the refrigerator  1  is installed. 
     The door  20  may have a structure in which a front surface selectively emits light and may be configured to glow with set color or brightness. Thus, a user may change front color or brightness of the door  20  without separating or disassembling the door  20  and may change the overall outer appearance of the refrigerator  1 . 
     Hereinafter, the structure of the door  20  will be described in detail with reference to drawings. 
       FIG.  2    is a perspective view of a refrigerator door according to an embodiment present disclosure.  FIG.  3    is a view illustrating a state in which a panel assembly is separated from the refrigerator door. 
     As illustrated in  FIGS.  2  and  3   , the door  20  may include a door body  21  forming the overall shape of the door  20 , and a panel assembly  30  forming a front appearance of the door  20 . That is, the door  20  may be configured in such a way that the panel assembly  30  is mounted on a front surface of the door body  40 . 
     The door body  40  may include a body plate  41  defining a front surface and a door liner  42  defining a, rear surface. 
     The body plate  41  may be formed of a metal material and may be formed in a plate shape having a size corresponding to the panel assembly  30 . The door liner  42  may be formed of a plastic material and may form a bottom shape of the door  20 . 
     The door body  40  may further include a side decoration  44  forming right and left side surfaces of the door body  21 . The side decoration  44  may connect right and left side ends of the body plate  41  and right and left side ends of the door liner  42 . 
     The door body  40  may include an upper cap decoration  43  and a lower cap decoration  45  that form top and bottom surfaces of the door body  40 . The upper cap decoration  43  may be connected to an upper end of the side decoration  44 , an upper end of the body plate  41 , and an upper end of the door liner  42 . The lower cap decoration  45  may be connected to a lower end of the side decoration  44 , a lower end of the body plate  41 , and a lower end of the door liner  42 . 
     An outer appearance of the door body  40  may be formed by the body plate  41 , the door liner  42 . the side decoration  44 , the upper cap decoration  43 , and the lower cap decoration  45 . 
     An insulator may be filled in an internal space of the door body  40 , which is formed by coupling the body plate  41 , the door liner  42 , the side decoration  44 , the upper cap decoration  43 , and the lower cap decoration  45 , and may provide an insulation structure to prevent heat from being transferred through the door  20 . The insulator may be formed, for example, as a time elapses after a foaming liquid is filled. The door body  40  may be provided with an injection hole for filling the foaming liquid. 
     An opened forward panel receiving space  410  may be formed on a front surface of the door body  40 . That is, front ends of the side decoration  44 , the upper cap decoration  43 , and the lower cap decoration  45  may protrude more forward than the front surface of the body plate  41 . 
     A panel receiving space  410  that is opened forward may be defined at a front side of the door body  40 . The panel receiving space  410  may be formed with a size corresponding to the size of the panel assembly  30  and the panel assembly  30  may be inserted into the panel receiving space  410 , A circumference of the panel assembly  30  may be supported by a circumferential surface of the panel receiving space  410 , that is, protruding portions of the side decoration  44 , the upper cap decoration  43 , and the lower cap decoration  45 . 
     The panel assembly  30  may be formed in a plate shape as a whole and may be formed with a size corresponding to a front surface of the door body  40 . Thus, when the panel assembly  30  is mounted on the front surface of the door body  40 , the panel assembly  30  may shield the front surface of the door body  40  and may form an outer appearance of the front surface of the door  20 . Since the panel assembly  30  may form the outer appearance of the front surface of the door  20 , the panel assembly  30  may be referred to as a door panel, and since the panel assembly  30  may form the outer appearance of the front surface of the refrigerator  1 , the panel assembly  30  may also be referred to as an exterior panel. 
     In the state in which the panel assembly  30  is mounted on the door body  40 , a rear surface of the panel assembly  30  may be fixed in contact with the body plate  41 . To fixedly mount the panel assembly  30 , a lower end of the panel assembly  30  may be caught and restrained with a lower end of the lower cap decoration  45 , and an upper end of the panel assembly  30  may be coupled to an upper end of a front surface of the upper cap decoration  43  to firmly couple the panel assembly  30  to the door body  40 . The panel assembly  30  may be detachably mounted from the door body  40  for services and maintenance. 
     A front surface of the panel assembly  30  may be exposed forward in the state in which the panel assembly  30  is mounted on the door body  40 , and the panel assembly  30  may substantially form the outer appearance of the front surface of the door  20 . The panel assembly  30  may be configured to emit light from an entire front thereof and may be configured to glow with various colors. 
     To this end, a lighting device  36  may be provided inside the panel assembly  30 . A wire (not shown) may be connected to the lighting device  36  in order to supply and control power, The wire (not shown) may be exposed outside the rear surface of the panel assembly  30 , and a connector (not shown) may be provided on an end of the wire (not shown). 
     A structure connected to the connector of the wire to supply power to the lighting device  36  may be provided on a front surface of the door body  40 . 
     Hereinafter, the structure of the panel assembly  30  will be described in more detail with reference to drawings. 
       FIG.  4    is a cross-sectional view taken along line  4 - 4  of  FIG.  3   .  FIG.  5    is a view illustrating arrangement of a light guide plate and a light source. 
     Referring to  FIGS.  4  and  5   , the panel assembly  30  may include a front plate  31  forming an outer appearance of the front surface, the lighting device  36  for emitting light to cause the front plate  31  to glow, a light guide plate  33  for guiding the light emitted from the lighting device  36 , and a diffusion member  32  allowing the light guide plate  33  to be spaced apart from the front plate  31  and diffusing the light. The diffusion member  32  may also be referred to as a support member in terms of supporting the light guide plate  33 . 
     The lighting device  36  and the light guide plate  33  may be mounted or supported on the diffusion member  32 . 
     The panel assembly  30  may further include a back cover  39  defining a rear surface of the panel assembly  30 . 
     The front plate  31  may be formed in a rectangular plate shape and may be formed of a material that transmits light therethrough. For example the front plate  31  may be formed of a glass material such as blue glass, white glass, and vapor deposition glass or may be formed of other materials for transmitting light therethrough, such as ABS, PMMA, or PC. The front plate  31  may be referred to as a transparent plate or an out plate. 
     The front plate  31  may be formed to be transparent to allow light reflected by the light guide plate  33  to be transmitted. In this case, transparency may be defined to a degree to which light reflected from the light guide plate is transmitted and irradiated to the outside. 
     The front plate  31  may be formed to have color and may be formed to represent different colors depending on an operation or on and off states of the lighting device  36 . For example, a specific design or pattern may be printed on the front plate  31  to have specific color. A film with a specific design or pattern printed thereon may be added to the front plate  31 , surface treatment such as imprinting, etching, and glass printing may be performed on the front plate  31 , or a coating or deposition layer having specific color and texture may be formed to form an outer appearance of the front plate  31 . 
     The front plate  31  may be configured to transmit light emitted from the lighting device  36  but components behind the front plate  31  may not be seen therethrough. That is, in the state in which the lighting device  36  is turned off, components inside the panel assembly  30  may be prevented from being seen to the outside through the front plate  31  due to the color of the front plate  31 . 
     In this case, a color layer having color may be formed on the front plate  31 . In an off state, the color layer may be formed to have at least color having brightness equal to or greater than  0  other than black. That is, in a state in which the refrigerator  1  is installed, the front surface of the refrigerator  1  may be displayed in a color other than black, and the front color of the refrigerator may be changed according to an operation of the lighting device  36 . 
     In the panel assembly  30 , the entire front surface of the front plate  31  may be exposed to the outside. Thus, the light diffused by the diffusion member  32  may be transmitted through the front plate  31  as a whole, and thus, the entire front surface of the front plate  31  may glow. 
     A rear surface of he front plate  31  may be coupled to a front surface of the diffusion member  32 . 
     The light guide plate  33  may be positioned at a rear spaced apart from the front plate  31  by the diffusion member  32  and may be configured to guide light emitted from the lighting device  36  disposed at the upper end of the light guide plate  33  forward. 
     For example, the light guide plate  33  may be formed of transparent acrylic, plastic, or a transparent polymer material. The light guide plate  33  may have a diffusing agent added thereto for diffusing light entrance on the light guide plate  33  or a pattern for diffusing light may be further formed on the light guide plate  33 . Thus, light may be transferred to the front plate  31  by the light guide plate  33 , and in this case, a pattern of the light guide plate  33  may be set to cause the entire front surface of the front plate  31  to glow with uniform brightness. 
     A load of the light guide plate  33  may be supported by the diffusion member  32  and a front surface of the light guide plate  33  may be pressed toward the diffusion member  32  by the back cover  39 . 
     The diffusion member  2  may be disposed between the front plate  31  and the light guide plate  33 . The diffusion member  32  may allow the light guide plate  33  to be maintained at a predetermined distance from the front plate  31  and may diffuse light emitted from the light emission surface of the light guide plate  33 . 
     The front surface of the diffusion member  32  may support the front plate  31  and opposite side surfaces of the diffusion member  32  may restrain both ends of the light guide plate  33 . The front surface of the diffusion member  32  may have a size greater than or equal to that of the light guide plate  33 , and in the state in which the light guide plate  33  is mounted, the rear surface of the diffusion member  32  and the light guide plate  33  may be maintained in the state of being in surface contact with each other. 
     The diffusion member  32  may include a plate-shaped front surface portion  321 , on which the front plate  31  is mounted, and an extension portion extending from a circumference of the front surface portion  321 . The front surface portion  321  and the extension portion may define an accommodation space  320 a in which the light guide plate  33  is disposed. 
     The extension portion is disposed to cover the circumference of the light guide plate  33 . The circumference of the light guide plate  33  may include, for example, a top surface, a bottom surface, and both side surfaces. 
     For example, the extension portion may include an upper extension portion  322  extending from an upper end of a rear surface of the front surface portion  321 , a lower extension portion  324  extending from a lower end of the rear surface of the front surface portion  321 , and a pair of side surface portions extending from both left and right ends of the front surface portion  321 . 
     The upper extension portion  322 , the lower extension portion  324 , and the pair of side surface portions may define the accommodation space  320 a in which the light guide plate  33  is disposed. Thus, the diffusion member  32  not only serves to diffuse light, but also serves to accommodate and support the light guide plate  33 . 
     The front surface portion  321  may be formed like a plate corresponding to the front plate  31 , and a front surface of the light guide plate  33  may be in dose contact with a rear surface of the front surface portion  321 . 
     According to this embodiment, since the front surface portion  321  of the diffusion member  32  is entirely disposed between the front plate  31  and the light guide plate  33 , even if the light guide plate  33  is deformed by the heat, the light guide plate  33  may be prevented from being in direct contact with the front plate  31 . Thus, it is possible to prevent a dark area such as stains from occurring on the front plate  31 . 
     The front surface portion  321  and the rear surface of the front plate  31  may be coupled to each other by an adhesion portion  313 . The adhesion portion  313  may include, for example, a sealant or a double-sided tape. 
     The side surface portions may extend backward from right and left side ends of the front surface portion  321  and may be formed to restrain right and left side ends of the light guide plate  33 . The side surface portions may be spaced apart from at least one of both left and right side surfaces of the light guide plate  33 . When the light guide plate  33  moves to left and right sides, the side surface portions may be in contact with at least one surface of both the left and right side surfaces to restrict the at least one surface. When it is considered that the light guide plate  33  is expanded by heat, the side surface portions may be spaced apart from at least one of the left and right side surfaces of the light guide plate  33 . 
     Each of the upper extension portion  322  and the lower extension portion  324  extends backward from the front surface portion  321 , and a length of each of the upper extension portion  322  and the lower extension portion  324  is greater than a thickness of the light guide plate  33 . 
     The diffusion member  32  may be made of a material for transmitting light therethrough and may be entirely formed by injection or extrusion as a single component. 
     The diffusion member  32  may be made of a transparent or translucent material as a whole. The diffusion member  32  itself may be provided to have a color. Thus, when viewed from the front of the panel assembly  30 , a color, texture, or shape of the front surface of the panel assembly  30  may be determined by the diffusion member  32 . 
     The diffusion member  32  may further include a light guide plate support  326  supporting a bottom surface  333  of the light guide plate  33 . The light guide plate support  326  may extend backward from the rear surface of the front surface portion  321  and may be disposed above the lower extension portion  324  to be spaced apart from the lower extension portion  324 . 
     To stably support the load of the light guide plate  33 , the diffusion member  32  may include a plurality of light guide plate supports  326 . The plurality of light guide plate supports  326  may be disposed to be spaced apart from each other in the horizontal direction. 
     The lighting device  36  may be accommodated in the diffusion member  32 . The diffusion member  32  may include a receiving groove  324   a  (or receiving portion) that receives a portion of the lighting device  36 . 
     The receiving groove  324   a  may be defined as a rear portion of the front surface portion  321  is recessed forward. Thus, the portion in which the receiving groove  324   a  is defined in the front surface portion  321  may be thinner than other portions. 
     The receiving groove  324   a  may be defined between the light guide plate support  326  and the lower extension portion  324 . Thus, when the lighting device  36  is received in the receiving groove  324   a,  the lighting device  36  may be disposed below the light guide plate support  326 . 
     The lighting device  36  may include a substrate  361  and the light source  362 . The substrate  361  may be provided in a plate shape to be elongated in the left and right direction. 
     The plurality of light sources  362  may be arranged at a constant interval on the substrate  361 . The light source  362  may be disposed to radiate light toward the bottom surface  333  of the light guide plate  33 . That is, the bottom surface  333  of the light guide plate  33  is a light entrance surface, and the front surface  331  of the light guide plate  33  is the light emission surface. 
     The light source  362  may be disposed to emit light toward the lower end of the light guide plate  33 . 
     The light source  362  may be disposed vertically below the bottom surface  333  of the light guide plate  33 , i.e., may be disposed to face the bottom surface  333  of the light guide plate  33 . 
     The light source  362  may be provided as, for example, an LED. The light source  362  may be configured as an RGB LED capable of irradiating light with various colors according to a control of the controller  13 , which will be described later. That is, the light source  362  may emit light with various colors under control of the controller  13  that will be described later, and thus the front plate  31  may glow with color set by the controller  13 . A color of the front appearance of the refrigerator  1  may be determined according to color of the front plate  31 . 
     The light source  362  may include a light emitting diode (LED) for emitting light with specific color other than the RGB LED and may include a combination of a plurality of LEDs for emitting light with different colors. For example, the plurality of light sources  62  may include red, green, and blue LEDs and may sequentially and repeatedly arranged. Under control of the controller  13 , operations of the light sources  362  may be combined to cause the front plate  31  to glow with desired color. 
     An interval between the light sources  362  may be smaller than the right and left width of the light guide plate support  326 , and thus the light guide plate support  326  may be disposed between the light sources  362 . Thus, the light emitted from the light source  362  may pass between two adjacent light guide plate supports  326  and be irradiated to the bottom surface  333  of the light guide plate  33 . 
     The panel assembly  30  may further include a substrate supporter  37  seated on the lower extension portion  324  of the diffusion member  32 . 
     The substrate supporter  37  may support the substrate  361  while being seated on the lower extension portion  324 . A substrate supporter  37  may dissipate heat generated by the lighting device  36  by thermal conduction. 
     The substrate supporter  37  may be made of, for example, a metal material. For example, the substrate supporter  37  may be made of an aluminum material having high thermal conductivity. The substrate supporter  37  may be extruded with a metal material to have the same cross-sectional shape in the longitudinal direction. 
     A portion of the substrate supporter  37  may be received in the receiving groove  324   a.  The substrate supporter  37  may be in contact with the back cover  39  while the back cover  39  is assembled. Thus, the heat generated by the lighting device  36  may be transferred toward the back cover  39  through the substrate supporter  37  and may be dissipated through the back cover  39 . 
     The panel assembly  30  may further include a rear supporter  34  supporting the rear surface of the light guide plate  33 . The rear supporter  34  may be provided in a plate shape and may be attached to the rear surface of the light guide plate  33  by an adhesive. 
     The rear supporter  34  may be made of an opaque material through which light transmission is restricted. The rear supporter  34  may be accommodated in the accommodation space  320 a defined by the diffusion member  32 . The upper extension portion  322  may cover an upper side of the rear supporter  34 , and the side portions  327  and  328  may cover both the side surfaces of the rear supporter  34 . 
     A bottom surface of the rear supporter  34  may be disposed above the substrate  361 . For example, a bottom surface of the rear supporter  34  may be seated on a top surface of the substrate  361 . 
     In this case, the upward movement of the substrate  361  may be restricted by the rear supporter  4 , Since the bottom surface  333  of the light guide plate  33  is seated on the top surface of the light guide plate support  226 , a set interval may be maintained between the bottom surface of the light guide plate  33  and the light source  362 . 
     As described above, the lighting device  36  may be maintained in the fixed state, and a distance between the light guide plate  33  and the light source  362  may also be maintained at a set distance, and thus, the light irradiated from the light source  362  may be incident into the light guide plate  33  at a designed angle. Thus, the light irradiated from the light source  362  may be effectively irradiated toward the light guide plate  33 , and the light reflected through the light guide plate  33  may allow the front plate  31  to glow with set brightness. 
     In another aspect, the rear supporter  34  may be seated on the light guide plate support  326 . 
     The rear supporter  34  may include an opening  342  through which a portion of the back cover  39  passes. 
     The back cover  39  may include a cover body  391  and a bent portion extending from an edge of the cover body  391  in the horizontal direction. 
     The cover body  391  may be in contact with the rear surface of the rear supporter  34 . The cover body  391  may be attached to the rear supporter  34  by the adhesive or may be coupled to the rear supporter  34  by a coupling member such as a screw. 
     The bent portion may extend forward from the edge of the cover body  391  and may include an upper bent portion  393 , a lower bent portion  396 , and a pair of side bent portions. The bent portion may be in contact with the diffusion member  32 . For example, the bent portion may adhere to the extension portion of the diffusion member  32  by the adhesive. 
     For example, the upper bent portion  393  may be seated in an upper seating groove  323  having a recessed shape defined in the upper extension portion  322  of the diffusion member  32 . 
     The lower bent portion  396  may be in contact with a bottom surface of the lower extension portion  324  of the diffusion member  32 . The side bent portions may be seated in the recessed side seating grooves defined in the side extension portions. 
     In this embodiment, since the diffusion member  32  supports the light guide plate  33  and fixes a position of the light guide plate  33 . and the back cover  39  is coupled to surround a portion of the diffusion member  32 , the number of components of the panel assembly  30  itself may be reduced to reduce a thickness of the panel assembly in the front and rear direction. 
     The cover body  391  may further include a pressing portion  392  bent toward the light guide plate  33 . The pressing portion  392  may pass through the opening  342  of the rear supporter  34  so as to be in contact with the rear surface of the light guide plate 
     In this embodiment, the cover body  391  may press the rear supporter  34  toward the rear surface side of the light guide plate  33  while being in contact with the rear surface of the rear supporter  34 , and the pressing portion  392  may directly press the light guide plate  33 . 
     The receiving groove  324   a  may be defined at a position equal to or lower than that of the bottom surface  311  of the front plate  31 . That is, a portion of the front surface portion  321  may extend further downward than the bottom surface  311  of the front plate  31 . 
     The diffusion member  32  may diffuse the light irradiated from the light emission surface of the light guide plate  33 . Since a portion of the diffusion member  32  is disposed lower than the bottom surface  311  of the front plate  31 , there is a possibility that the light passing through the diffusion member  32  is directly irradiated to the outside without passing through the front plate  31 . To prevent this phenomenon, the panel assembly  30  according to this embodiment may further include a lower trim  35 . 
     The lower trim  35  may be coupled to the diffusion member  32  by a coupling means such as an adhesion portion or a hook. 
     The lower trim  35  may include a first portion  351  extending in the vertical direction and a second portion  352  extending in the horizontal direction from a lower end of the first portion  351 . 
     At least the first portion  351  may be provided to be transparent or translucent and, as necessary, may be provided with a specific color. 
     The first portion  351  may cover a portion of the diffusion member  32  extending downward from the bottom surface  311  of the front plate  31 . For example, the first portion  351  may be disposed to face the receiving groove  324   a  in front of the receiving groove  324   a  in the diffusion member  32 . 
     The second portion  352  may support the lower extension portion  324 . The second portion  352  may include a seating groove  353  for seating the lower bent portion  396  of the back cover  39 . 
       FIG.  6    is a vertical cross-sectional view showing a light emitting state of the panel assembly.  FIG.  7    is a block diagram illustrating a flow of a control signal of the refrigerator.  FIG.  8    is a view illustrating a state in which all doors glow in a refrigerator.  FIG.  9    is a view illustrating a state in which some doors of a plurality of doors glow. 
     Referring to  FIGS.  6  to  9   , in the refrigerator  1  according to an embodiment of the present disclosure, a front surface of the door  20  may glow via an operation of the lighting device  36 . 
     The front surface of the door  20  may glow with any one of a plurality of colors under control of the controller  13 . 
     The operation of the lighting device  36  may be performed by manipulation of a manipulator  14  of a user. The manipulator  14  may be disposed at one side of the refrigerator  1 , and for example, may be disposed at one side of the cabinet  10 . Needless to say, as necessary, the manipulator  14  may be included in the door  20  or manipulation may be input by touching and manipulating the front plate  31 . That is, the user may directly manipulate the manipulator  14  to set an operation of the lighting device  36  and may turn on or off the lighting device  36 . 
     The user may set an operation state of the lighting device  36 , such as an operation time and an operation condition of the lighting device  36  and emission color of the light source  362  through manipulation of the manipulator  14 . 
     Various commands related to an operation of the refrigerator may be input through manipulation of the manipulator  14 . 
     As necessary, the manipulator  14  may be configured as a display for information display and manipulation. 
     The lighting device  36  may also be manipulated in operation and set in operation condition through a remote device  2  spaced apart from the refrigerator  1 . The refrigerator  1  may communicate with the remote device  2  through a communicator  17  connected to a controller  13 , and the user may control an operation of the lighting device  36  through the remote device  2 . 
     The communicator  17  may communicate with the remote device  2  and/or a server for managing the home appliance using various methods. 
     For example, the communicator  17  may have a configuration for communication using at least one method of wired, wireless, or short distance communication (Bluetooth, Wi-Fi, Zigbee, and NFC). The remote device  2  may be various devices that are capable of communicating, such as a dedicated terminal, a mobile phone, a tablet, a portable PC, a desktop PC, a remote control, or a Bluetooth speaker. 
     The user may manipulate and set the operation state of the lighting device  36 , such as an operation time and an operation condition of the lighting device  36  and emission color through manipulation of the remote device  2 , For example, the lighting device  36  may be simply manipulated and set through an application or a dedicated program installed in a portable phone of the user. 
     The communicator  17  may receive information about the current time through the remote device  2  or the server. The received current time information may be stored in a memory  18 , and the controller  13  may recognize the current time in real time. 
     The refrigerator  1  may further include a timer  16 . The timer  16  may count an elapsed time after a specific event occurs. For example, the refrigerator  1  may receive information about the current time through the communicator  17 , and when communication failure of the communicator  17  is recognized (when a specific event occurs), the timer  16  may operate. In this case, in consideration of the time counted by the timer  16 , the refrigerator  1  may indirectly recognize the current time. Then, when communication failure of the communicator  17  is released, the timer  16  may be stopped, and information on the current time determined based on the timer  16  may be changed to information about the current time received from the communicator  17 . 
     The lighting device  36  may also be operated according to the detection result by a sensor  15 . 
     The sensor may include a user detection sensor  151  for detecting proximity of the user. For example, the user detection sensor  151  may use various devices for detecting user approaching near the refrigerator, such as an infrared sensor, an ultrasonic sensor, or a laser sensor. 
     The user detection sensor  151  may be disposed at various positions for detecting proximity of the user, such as one side of the cabinet  10  or one side of the door  20 , and may be disposed at various positions for detecting proximity of the user. A plurality of sensors may be disposed at different positions. 
     Thus, when the user approaches the refrigerator  1  by a reference distance for use of the refrigerator  1 , the user detection sensor  151  may detect this and may transfer a signal to the controller  13  to turn on the lighting device  36 . When the user moves away from the refrigerator  1 , the user detection sensor  151  may detect this and may transfer a signal to the controller  13  to turn off the lighting device  36 . 
     When the user detection sensor  151  is provided in the cabinet  10 , the user detection sensor  151  may be located on a front surface of the cabinet  10  corresponding to a space between an upper door and a lower door. Since the upper door and the lower door are spaced apart, there may be a gap between the upper door and the lower door. Accordingly, when the user detection sensor  151  is disposed at a position corresponding to the gap, the user may be capable of approaching the user detection sensor  151 . 
     The sensor  15  may further include an illuminance sensor  152 . The illuminance sensor  152  may detect an illuminance around the refrigerator  1 . The illuminance sensor  152  may be provided in the cabinet  10  or the door  20 . 
     The refrigerator  1  may further include a motion sensor  19 . The motion sensor  19  may detect a movement of a person, an object, an animal, etc. on the floor on which the refrigerator  1  is installed. 
     The motion sensor  19  may be installed in the lower door or installed at a lower position than the lower door in the cabinet  10 . Needless to say, it may also be possible that the motion sensor  19  is installed in the upper door, however, it may be arranged to detect a motion on the floor in the upper door. 
     The operation state of the lighting device operated by the controller is now described. As shown in  FIG.  6   , when the lighting device  36  is turned on according to an instruction of the controller  13 , light emitted from the light source  362  may be directed toward the bottom surface  333  of the light guide plate  33  and then guided along the light guide plate  33 . 
     In this case, the light guided by the light guide plate  33  may pass through the light emission surface and be diffused while passing through the front surface portion  321 , and then, may pass through the front plate  31  and be transmitted to the outside. Thus, the entire front plate  31  may brightly glow, and the front surface of the door  20  may glow with a set brightness or color. 
     The lighting device  36  may be turned on to cause the front surface of the door  20  to glow brightly, and the front surface of the door  20  may glow with set color by light emitted from the light source  362 . In this case, the front color of the door  20  may be different color or brightness from in the state in which the lighting device  36  is turned off. 
     That is, a color of the front surface of the door  20  may be seen as a color of the front plate  31 , and the texture and pattern disposed on the front plate  31  may be seen. In this case, the color of the front plate  31  may be color with a brightness greater than 0 and may be formed in a color other than black. The color of the front surface of the door  20  in the state in which the lighting device  36  is turned may also be referred to as a first color. 
     Thus, the front surface of the door  20  may be seen with color of the front plate  31 , and in this case, components inside the panel assembly  30  may be seen through the front plate  31  and may not be seen to the outside by the color of the front plate  31 . 
     In this state, the lighting device  36  may be turned on, and when the lighting device  36  is turned on, the front surface of the door  20  may glow with color set by the controller  13 . 
     The controller  13  may control the front surface of the door  20  to glow with a second color different from the first color. The controller  13  may control the light source  362  to glow with the second color. 
     In this case, color emitted from the light source  362  may be different from the second color. That is, since the front plate  31  includes first color, if light of the second color is emitted from the light source  362 , the light may interact with the first color while passing through the front plate  31  to actually glow with a third color. 
     Accordingly, in the present embodiment, control of the light source  362  to allow the door  20  to glow with a specific color may mean control of color emitted from the light source  362  in consideration of the color itself of the front plate  31 . 
     That is, in the state in which the light source  362  is turned on, color with which the door  20  glows may be color formed by mixing color itself of the front plate  31  and color of light emitted from the light source  362 . 
     Some of the plurality of doors  20  forming the front appearance of the refrigerator  1  may emit light or the plurality of doors  20  may independently emit light to form the front appearance of the refrigerator  1  with set color. 
     The refrigerator  1  may be operated to cause some doors  20  of a plurality of doors to glow or glow with specific color. That is, all the lighting devices  36  included in the doors  20  may not be operated, but instead, only some of all the doors  20  may glow. For example, any one door  201 a of the refrigerating compartment door  201  may glow. 
     As necessary, the left refrigerating compartment door  201 a and the right refrigerating compartment door  201 b may glow with different colors. At least two of the doors  20  may be sequentially changed in color and at least two of the doors  20  may be sequentially turned on or off. 
     In this case, the lighting device  36  included in the panel assembly  30  may be controlled by the controller  13  according to the aforementioned various conditions. 
     The refrigerating compartment door or the freezing compartment door among the doors may be controlled to glow with different colors. 
     The controller  13  may control the lighting device  36  to cause one pair of the refrigerating compartment doors  201  to be seen with the first color. The controller 13  may control the lighting device  36  to cause one pair of the refrigerating compartment doors  201  to be seen with the second color. 
     That is, the refrigerating compartment door  201  and the freezing compartment door  202  may be distinguished therebetween with colors, and according to a temperature change inside the refrigerator, the colors of the refrigerating compartment door  201  and the freezing compartment door  202  may also be changed. 
     Thus, through the front color of the door  20 , the user may intuitively recognize an operation state of each storage space as well as may distinguish between the refrigeration compartment and the freezing compartment. 
     Hereinafter, a detailed operation control of the lighting device  36  will be described. 
     For convenience of description, in the refrigerator, the upper two doors are referred to as a first door and a second door, and the two doors below the first door and the second door are referred to as a third door and a fourth door. 
     In the case of the upper first door and second door, the light source  362  may be located at a lower side of each of the first door and the second door. In the case of the lower third door and fourth door, the light source  362  may be positioned at an upper side of each of the third door and the fourth door. Needless to say, it may also be possible that the light source  362  is located at a lower side of each of the third door and the fourth door. 
     In addition, with respect to operation control of the lighting device  36  described below, the present disclosure is not limited to the configuration of the panel assembly described above. That is, at least one of a plurality of components configuring the panel assembly may be omitted, at least one of a plurality of components may be replaced with another component, or the location of at least one component among a plurality of components may be changed. 
     In the present specification, a state change of the light source  362  may include one or more of a case in which the light source  362  is changed from an off state to an on state, a case in which the light source  362  is changed from an on state to an off state, a case in which one or more LEDs are turned on in a state in which the light source  362  is turned off, a case in which the light source  362  is turned off in a state in which one or more LEDs are turned on, a case in which brightness of light emitted from the light source  362  is changed in a state in which the light source  362  is turned on, a case in which the brightness or color of light emitted from some of a plurality of LEDs is changed in a state in which the light source  362  is turned on, the number of LED lights is changed an increase in the number of LED lights or a decrease in the number of LED lights), and a case in which color of light emitted from the light source  362  is changed in a state in which the light source  362  is turned on. 
     The state in which the light source  362  is turned on may mean a state in which all of a plurality of LEDs are turned on, and the state in which the light source  362  is turned off may mean a state in which all of the plurality of LEDs are turned off. 
       FIG.  10    is a flowchart for explaining a control method of differently setting a reference distance according to illuminance according to the present embodiment. 
     Referring to  FIGS.  7  and  10   , the illuminance sensor  152  may periodically detect the illuminance around the refrigerator  1  (S 1 ). 
     The controller  13  may operate the mode of the refrigerator  1  as a first mode or the second mode according to the illuminance value detected by the illuminance sensor  152 . 
     The controller  13  may determine whether the refrigerator  1  needs to be operated in the first mode according to the illuminance value detected by the illuminance sensor  152  (S 2 ). 
     The controller  13  may operate the refrigerator  1  in the first mode when the illuminance value is greater than a reference illuminance value. 
     In the first mode, a reference distance for user proximity detection may be set to a first reference distance (S 3 ). 
     In the state in which the first reference distance is set, when a user is detected to approach the refrigerator within the first reference distance by the user detection sensor  151 , the controller  13  may control the light source  362  of one or more doors among a plurality of doors to change from the first state to the second state (S 5 ). 
     On the other hand, as the determination result of operation S 2 , when the refrigerator  1  may not need to operate in the first mode, it may be determined that the refrigerator  1  needs to be operate in the second mode. That is, when the illuminance value is smaller than the reference illuminance value, the controller  13  may operate the refrigerator  1  in the second mode. 
     In the second mode, a reference distance for user proximity detection may be set as a second reference distance (S 6 ). 
     That is, in the present embodiment, the reference distance may be variably set based on the illuminance sensed by the illuminance sensor  152 . 
     In the state in which the second reference distance is set, when the user is detected to approach within the second reference distance by the user detection sensor  151 , the controller  13  may control the light source  362  of one or more doors among a plurality of doors to change from the first state to the second state (S 8 ). 
     For example, in operations  35  and S 8 , a state change of the light source may include a state in which the light source  362  of some of a plurality of doors are turned on or a state in which the light source  362  of each of a plurality of doors is turned off. 
     In the present embodiment, the second reference distance may be greater than the first reference distance. 
     The case in which the refrigerator operates in the second mode may be the case in which the illuminance around the refrigerator  1  is low. In this case, when the user approaches the refrigerator  1 , the reference distance may be set as a second reference distance in order for the user to easily recognize the location of the refrigerator  1  from a distance. 
     When illuminance is low, the user may recognize the refrigerator only when the user approaches the refrigerator, and there is a risk that the user collides with a nearby object while approaching the refrigerator. 
     When illuminance is low, even if the user approaches the refrigerator  1  within the first reference distance, there may be a possibility that the user does not recognize the refrigerator  1 . Therefore, as in the present disclosure, when the second reference distance greater than the first reference distance is set if illuminance is low, the user may easily recognize the refrigerator even at a location far away from the refrigerator, and thus the user may easily recognize the refrigerator, thereby preventing the user from colliding with a nearby object during a process of approaching the refrigerator. 
     As such, when the user approaches the refrigerator  1  within the second reference distance in the second mode, the light source  362  may be turned on, and thus the refrigerator may serve as a lighting. 
     When the refrigerator  1  serves as a lighting, the user may easily approach the refrigerator  1  as well as easily recognize an object around the refrigerator  1 . 
     In contrast, the case in which the refrigerator operates in the first mode may be the case in which illuminance around the refrigerator  1  is high. 
     In this case, when the user approaches the refrigerator  1 , there is a high possibility that the user recognizes the refrigerator even if a distance between the user and the refrigerator is the second reference distance. 
     Accordingly, in this case, the light source  362  may be turned on when the user approaches the first reference distance by setting the first reference distance smaller than the second reference distance. Accordingly, by reducing a time when the light source  362  is turned on, power consumption may be reduced. Also, it is possible to reduce frequent turning on of the light source  362 . 
     In the first mode, when the user approaches the refrigerator  1  within the first reference distance and the light source  362  is turned on, the refrigerator  1  may change the user&#39;s mood as well as simply store food, the refrigerator  1  may serve as interior furniture. 
     Depending on the user&#39;s preference, the user may not want to change the state of the light source  362  when approaching the refrigerator. Accordingly, a function of changing the state of the light source  362  according to approach of the user may be set or release by user selection. For example, the user may set or release the function using the manipulator  14 . Alternatively, the function may be set or released through the remote device  2 . 
     If the brightness of light is the same when the light source  362  is turned on in each of the first mode and the second mode regardless of the illuminance, when the light source  362  is turned on in the second mode, light of the light source  362  may make a user feel glare. 
     Therefore, the brightness of light of the light source  362  when the light source  362  is on in the second mode may be smaller than the brightness of light of the light source  362  when the light source  362  is on in the first mode. 
     In the first mode, after the state of the light source  362  is changed, if a user is not detected within the first reference distance, the state of the light source  362  may be changed to a previous state. For example, the light source  362  may be turned off after being turned on. 
     In the second mode, after the state of the light source  362  is changed, if a user is not detected within the second reference distance, the state of the light source  362  may be changed to a previous state. For example, the light source  362  may be turned off after being turned on. 
     The first reference distance and the second reference distance may be set by a user. For example, the user may set or change each of the first reference distance and the second reference distance through the manipulator  14 . Alternatively, each of the first reference distance and the second reference distance may be set or changed through the remote device  2 , and the set or changed information may be received by the communicator  17  and stored in the memory  18 . 
     However, a changeable reference distance range may be preset, and the user may select the first reference distance and the second reference distance within the corresponding range. 
     In another example, when the user selects a button such as “Register current distance” using a remote device while standing at a desired position, an actual distance from the refrigerator to the user may be set as a reference distance. 
     The reference illuminance value may also be set by a user. For example, the user may set and change the reference illuminance value through the manipulator  14 . Alternatively, the reference illuminance value may be set and changed through the remote device  2 , and the set and changed information may be received by the communicator  17  and stored in the memory  18 . 
     However, a range of the changeable reference illuminance value may be preset, and the user may select the reference illuminance value within the corresponding range. 
     According to another embodiment, the reference distance may vary based on the current time. When the current time satisfies a first time range to be described later, the reference distance may be set as a first reference distance. On the other hand, when the current time satisfies a second time range to be described later, the reference distance may be set as a second reference distance. That is, step S 1  in  FIG.  10    may be changed to a step of recognizing the current time. 
     In another example, the reference distance may also be variably set based on the current time and the detected illuminance value. 
       FIG.  11    is a flowchart for explaining a method of setting an operation mode according to illuminance and current time according to the present embodiment. 
     Referring to  FIGS.  7  and  11   , as described above, the controller  13  may recognize the current time. 
     The controller  13  may set an operation mode of the refrigerator  1  based on the illuminance value and current time detected by the illuminance sensor  152 . 
     For example, the illuminance sensor  152  may continuously or periodically detect an illuminance around the refrigerator  1  (S 11 ). 
     When the current time satisfies a first time range and the detected illuminance value satisfies a first illuminance range (S 12 ), the controller  13  may set an operation mode of the refrigerator  1  to a first operation mode (S 16 ). 
     The first time range may be set, for example, in the range of 6 am to 6 pm. The first illuminance range may be set to a range greater than or equal to the reference illuminance value. 
     For example, the first operation mode may be set when the illuminance around the refrigerator  1  is high in the daytime. 
     When the current time satisfies a first time range and the detected illuminance value satisfies a second illuminance range (S 13 ), the controller  13  may set an operation mode of the refrigerator  1  to a second operation mode (S 17 ). 
     The second illuminance range may be set to a range less than the reference illuminance value. 
     For example, the second operation mode may be set hen the illuminance around the refrigerator  1  is low in the daytime. 
     When the current time satisfies a second time range and the detected illuminance value satisfies the first illuminance range (S 14 ), the controller  13  may set an operation mode of the refrigerator  1  to a third operation mode (S 18 ). 
     The second time range may be set, for example, in the range of 6 pm to 6 am. The first time range and the second time range may be set or changed by a user. 
     For example, the third operation mode may be set when the illuminance around the refrigerator  1  is high in the evening. 
     When the current time satisfies a second time range and the detected illuminance value satisfies the second illuminance range (S 15 ), the controller  13  may set an operation mode of the refrigerator  1  to a fourth operation mode (S 19 ). 
     For example, the fourth operation mode may be set when the illuminance around the refrigerator  1  is low in the evening. 
     The controller  13  may control the refrigerator  1  in the set operation mode. 
     In the first operation mode, when the light source  362  is turned on in a specific door, the brightness of light emitted from the light source  362  may be set to a first value. 
     In the second operation mode, when the light source  362  is turned on in a specific door, the brightness of light emitted from the light source  362  may be set to a second value, The second value may be smaller than the first value. Although not limited, the second value may be 50% of the first value. 
     In the third operation mode, when the light source  362  is turned on in a specific door, the brightness of light emitted from the light source  362  may be set to a third value. In this case, the third value may be equal to or smaller than the first value. 
     In the fourth operation mode, when the light source  362  is turned on in a specific door, the brightness of light emitted from the light source  362  may be set to a fourth value. In this case, the fourth value may be smaller than the second value and the third value. The fourth value may be 25% of the first value. 
     In another example, in the first operation mode, when the light source  362  is turned on in specific door, the number of LEDs that are turned on may be set to a first number. 
     In the second operation mode, when the light source  362  of a specific door is turned on the number of LEDs that are turned on may be set to a second number. The second number may be smaller than the first number. Although not limited, the second number may be 50% of the first number. 
     In the third operation mode, when the light source  362  of a specific door is turned on, the number of LEDs that are turned on may be set to a third number. The third number may be equal to or smaller than the first number. 
     In the fourth operation mode, when the light source  362  of a specific door is turned on, the number of LEDs that are turned on may be set to a fourth number. The fourth number may be smaller than the second number and the third number. Although not limited, the fourth number may be 25% of the first number. 
     The above-mentioned values for the brightness and the number of LEDs that are turned on may be manually set and changed by a user. 
     According to the present embodiment, if the illuminance is low even in the daytime, the brightness of light may be set to be large when the light source  362  is turned on, and if the illuminance is high even in the night, the brightness of light may be set to be small when the light source  362  is turned on. 
       FIG.  12    is a flowchart for explaining a method of controlling a refrigerator during an operation in a first operation mode or a second operation mode,  FIG.  13    is a flowchart for explaining a method of controlling a refrigerator during an operation in a third operation mode or a fourth operation mode. 
       FIGS.  12  and  13    illustrate an example of setting a reference distance based on a current time. 
     First, referring to  FIG.  12   , the refrigerator  1  may be operated in a first operation mode or a second operation mode within the first time range (e.g., daytime) (S 21 ). 
     In the first operation mode or the second operation mode, the reference distance may be set to the first reference distance. 
     The controller  13  may determine whether the user is detected to approach the refrigerator within the first reference distance by the user detection sensor  151  (S 22 ). 
     When determining that the user approaches the refrigerator within the first reference distance, the controller  13  may control the light source  362  of each of the plurality of doors to be changed from the first state to the second state (S 23 ). For example, the light source  362  of each of the plurality of doors may be turned on. 
     The color of light emitted from the light source  362  when the light source  362  is turned on may be manually set and changed by the user. 
     In the state in which the light source  362  is turned on, when it is determined that the user is detected to approach the refrigerator within the first reference distance, the color of the light source  362  may be changed. For example, while the light source  362  is turned on to emit light with first color, if it is determined that the user is detected to approach the refrigerator within the first reference distance, the color of light emitted from the light source  362  may be changed to second color. 
     As described above, the brightness of light of the light source  362  in the first operation mode may be different from the brightness of light of the light source  362  in the second operation mode. 
     In the first time range, even when the light source  362  of each of the plurality of doors is turned on, the user does not feel glare, and the entire refrigerator may serve as a lighting or interior furniture. 
     Hereinafter, referring to  FIG.  13   , the refrigerator  1  may be operated in a third operation mode or a fourth operation mode within the second time range (e.g., daytime) (S 31 ). 
     In the third operation mode or the fourth operation mode, the reference distance may be set to the first reference distance. 
     The controller  13  may determine whether the user is detected to approach the refrigerator within the second reference distance by the user detection sensor  151  (S 32 ). 
     When determining that the user approaches the refrigerator within the second reference distance, the controller  13  may control the light source  362  of some of the plurality of doors to be changed from the first state to the second state (S 33 ). 
     For example, the light source  362  of a lower door of the plurality of doors may be turned on. The color of light emitted from the light source  362  when the light source  362  is turned on may be manually set and changed by the user. 
     Generally, when an adult approaches the refrigerator  1 , the eyes of the adult may be positioned higher than the lower door. If the user approaches the refrigerator  1  within the second reference distance and the light source of the upper door may be turned on, the user may feel glare. 
     On the other hand, according to the present embodiment, when the user approaches the refrigerator within the second reference distance and the light source of the lower door is turned on, the lower door may act as an indirect lighting while the user does not feel glare. 
     After the user is detected to approach the refrigerator within the second reference distance, the controller  13  may determine whether the user is detected to approach the refrigerator within the third reference distance by the sensor  15  (S 34 ). 
     The third reference distance may be smaller than the second reference distance. 
     When determining that the user is detected to approach the refrigerator within the third reference distance, the controller  13  may control the light source  362  of the remaining doors of the plurality of doors to be changed from the first state to the second state (S 35 ). 
     When the user is detected to approach the refrigerator within the third reference distance after the light source  362  of the lower door is turned on, the light source  362  of the upper door may be additionally turned on. 
     As described above, the brightness of light of the light source  362  in the third operation mode may be different from the brightness of light of the light source  362  in the fourth operation mode. 
     After the light source  362  of each of the plurality of doors is changed from the first state to the second state, when the user is not detected to approach the refrigerator within the second reference distance (when the user is farther away from the refrigerator than the second reference distance), the controller  13  may control the light source  362  to be changed to a previous state. 
     In another example, when the reference distance is to be changed based on the sensed illuminance value, operation S 21  in  FIG.  12    may be replaced with an operation performed in the first operation mode or the third operation mode, In addition, operation S 31  in  FIG.  13    may be replaced with a step performed in the second operation mode or the fourth operation mode. 
       FIG.  14    is a diagram for explaining a method of controlling a refrigerator according to motion detection of a motion sensor when the refrigerator operates in the third operation mode or the fourth operation mode. 
     Referring to  FIG.  14   , the refrigerator  1  may operate in the third operation mode or fourth operation mode described with reference to  FIG.  13   . 
     In this state, the motion sensor  19  may detect a motion of a person, an object, an animal, or the like around the refrigerator  1 . 
     The controller  13  may determine whether or not a set number of movements or more are detected by the motion sensor  19  (S 42 ). 
     As the result of determination in operation S 42 , if it is determined that a movement of more than the set number of times is detected by the motion sensor  19 , the controller  13  may control the light source of some of the plurality of doors to be changed from the first state to the second state during a set time (S 43 ). 
     A case in which the motion sensor  19  detects a movement more than the set number of times may be, for example, a case in which a pet frequently moves around the refrigerator. In this case, the light source of at least one door among the plurality of doors may be turned on in such a way that the refrigerator is capable of serving as a lighting. 
     In this case, even if the user does not approach the refrigerator within the second reference distance, the refrigerator may serve as an indirect lighting, and the light source of the lower door may be turned on to minimize fatigue of the eyes of the user. 
     After the light source of at least one door among the plurality of doors is changed from the first state to the second state for a set time, the light source  362  may be changed to a previous state. That is, the light source  362  that is turned on may be turned off. 
     In the present specification, when the user approaches the refrigerator within the reference distance, the state of the light source may be changed, and the reference distance for user detection may be changed based on the detected illuminance value. 
     When the illuminance value is low, if the reference distance is increased, the user may easily recognize a home appliance from a distance, thereby preventing the user from colliding with structures around the refrigerator while the user approaches the refrigerator. 
     In the present specification, according to the illuminance, the door capable of emitting light among the plurality of doors may be changeable. As in one embodiment, when the light source of the lower door is turned on if the illuminance is low and a time zone is night, it may be possible to prevent the user from feeling glare and the home appliance may advantageously serve as an indirect lighting,