Patent Publication Number: US-10330374-B2

Title: Refrigerator, and control method thereof

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the priority benefit of Korean Patent Application No. 10-2016-0129136, filed on Oct. 6, 2016 in the Korean Intellectual Property Office, and Korean Patent Application No. 10-2016-0179831, filed on Dec. 27, 2016 in the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference. 
     BACKGROUND 
     1. Field 
     The following description relates to a refrigerant having a dispenser, and a control method thereof. 
     2. Description of the Related Art 
     In general, a refrigerator is a home appliance including a storage chamber for storing food and a cool air supply apparatus for supplying cool air to the storage chamber to keep the food fresh. Recently, many refrigerators are released with a dispenser to enable a user to obtain water or ice cubes from the refrigerator from outside the refrigerator without opening a door of the refrigerator, in order to meet a user&#39;s demand. 
     SUMMARY 
     A refrigerator having a dispenser can discharge water or ice cubes produced therein to the outside through an outlet. An outlet opening/closing system of the refrigerator may open or close the outlet by rotating a motor. More specifically, the motor and a cam connected to the motor may rotate to operate an opening/closing module included in the outlet opening/closing system, thereby opening or closing the outlet. 
     More specifically, the opening/closing module may pivot with respect to an axis to open or close the outlet. At this time, the rotary motion of the motor may be converted into the reciprocating motion of the lever by the cam so that the opening/closing module can pivot with respect to the axis (hereinafter, also referred to as a pivot axis). 
     That is, the cam may be connected to the rotation axis of the motor to perform an eccentric motion with respect to the rotation axis of the motor, and the lever may perform a reciprocating motion according to the eccentric motion of the cam, so that the opening/closing module can pivot with respect to the pivot axis. 
     In this structure, the rotation axis of the motor and cam may be parallel to the pivot axis of the opening/closing module, and accordingly, the diameter of the motor or the diameter of the cam may influence the total thickness of the outlet opening/closing system, which limits the slimness of the outlet opening/closing system. 
     Also, because the lever needs to have a specific range of motion of a predetermined distance or more in order for the opening/closing module to smoothly open or close the outlet, the cam for operating the lever may need to have a predetermined size or larger. The size of the cam may also limit the slimness of the outlet opening/closing system. 
     An embodiment of the present disclosure provides a slim opening/closing system by changing the structure of a cam and the position of a motor. 
     Additional aspects of the disclosure will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the disclosure. 
     In accordance with an aspect of the present disclosure, an outlet opening/closing system of a refrigerator dispenser comprises a driver; a cam configured to rotate with respect to a first axis by the driver; and an opening/closing module configured to pivot with respect to a second axis according to the rotation of the cam to open the outlet, wherein the first axis crosses the second axis at a predetermined angle. 
     The outlet opening/closing system may further comprise a support member, wherein the opening/closing module may be pivotally coupled with the support member. 
     The driver may be coupled with the support member. 
     The outlet opening/closing system nay further comprises a spring, wherein the spring may provide the opening/closing module with a force of closing the outlet. 
     The first axis may be at right angles to the second axis. 
     The cam may include a cam surface and a circumference surface, wherein a first protrusion and a second protrusion are formed on the circumference surface of the cam. 
     The first protrusion and the second protrusion may be spaced apart from each other and arranged at a predetermined angle with respect to each other. 
     The outlet opening/closing system may further comprise a first switch module and a second switch module, wherein the first protrusion may operate the first switch module and the second switch module. 
     The outlet opening/closing system may further comprise a first switch module and a second switch module, wherein the second protrusion may operate the second switch module. 
     The cam surface may include a first flat surface, a second flat surface, a first inclined surface, and a second inclined surface, and the first flat surface and the second flat surface may have different heights. 
     The first protrusion may be formed on an area of the circumference surface, adjacent to the first flat surface, and the second protrusion may be formed on another area of the circumference surface, adjacent to the first inclined surface. 
     The opening/closing module may include a lever, and a protrusion may be formed on one side of the lever, and may contact the cam surface of the cam. 
     The lever may be integrated into the opening/closing module. 
     If the protrusion contacts the first flat surface, the opening/closing module may open the outlet maximally, and the first protrusion may operate the first switch module and the second switch module. 
     If the protrusion contacts the second flat surface, the opening/closing module may close the outlet. 
     The lever may be located at the upper area of the opening/closing module with respect to a center line dividing the opening/closing module in half. 
     The protrusion of the lever may include a spherical surface. 
     The lever may pivot the opening/closing module with respect to the second axis by a difference in height of the cam surface. 
     When the cam rotates one time, the opening/closing module may pivot from a closed state to an opened state and then again pivot to the closed state. 
     The cam surface of the cam may be formed to move the lever in a tangential direction of a circle whose center is on the second axis. 
     The second flat surface may maintain the opening/closing module in a closed state for a predetermined time period although the cam rotates. 
     The first flat surface may maintain the opening/closing module in an opened state for a predetermined time period although the cam rotates. 
     The driver may further include a reduction gear. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and/or other aspects of the disclosure will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which: 
         FIG. 1  shows the outer appearance of a refrigerator according to an embodiment of the present disclosure. 
         FIG. 2  shows the inside of the refrigerator according to an embodiment of the present disclosure. 
         FIG. 3  is a side cross-sectional view of the refrigerator according to an embodiment of the present disclosure. 
         FIG. 4  is an enlarged view of a dispenser of the refrigerator. 
         FIGS. 5A and 5B  are enlarged views showing the outlet and the opening/closing module of the dispenser. 
         FIG. 6  shows an outlet opening/closing system of opening or closing the outlet of the dispenser in the refrigerator according to an embodiment of the present disclosure. 
         FIG. 7A  is a perspective view of the cam. 
         FIG. 7B  is a top view of the cam. 
         FIG. 7C  shows the right side of the cam. 
         FIG. 7D  shows the left side of the cam. 
         FIG. 8  shows a state in which the opening/closing module is closed. 
         FIG. 9  shows an opened state of the opening/closing module. 
         FIG. 10  shows a rotation vector direction of the opening/closing module and vertical vector directions of the cam surfaces. 
         FIGS. 11 and 12  show a state in which the cam contacts the first switch lever and the second switch lever when the opening/closing module is in an opened state. 
         FIG. 13  shows a state in which the cam contacts the first switch lever and the second switch lever when the opening/closing module is in a closed state. 
         FIG. 14  shows the first switch module and the second switch module. 
         FIG. 15  is a perspective view of an opening/closing system according to an embodiment of the present disclosure. 
         FIG. 16  is a top view of the opening/closing system according to an embodiment of the present disclosure. 
         FIG. 17  is a front view of the opening/closing system according to an embodiment of the present disclosure. 
         FIG. 18  is a perspective view of the support member of the opening/closing system according to an embodiment of the present disclosure. 
         FIG. 19  is a perspective view of the cam used in the opening/closing system according to an embodiment of the present disclosure. 
         FIG. 20A  shows the outer appearance of the door of a refrigerator according to an embodiment of the present disclosure. 
         FIG. 20B  shows the internal structure of the refrigerator door shown in  FIG. 20A . 
         FIG. 20C  is a projected view showing a portion (a portion surrounded by dotted lines of  FIG. 20A ) of a refrigerator door according to an embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the drawings, like reference numerals represent members that perform the substantially same functions. 
       FIG. 1  shows the outer appearance of a refrigerator according to an embodiment of the present disclosure. 
       FIG. 2  shows the inside of the refrigerator according to an embodiment of the present disclosure. 
       FIG. 3  is a side cross-sectional view of the refrigerator according to an embodiment of the present disclosure. 
       FIG. 4  is an enlarged view of a dispenser of the refrigerator. 
     The following description will be given with reference to all of  FIGS. 1 to 4  in order to avoid duplication of description. 
     A refrigerator  1  is equipment to keep objects at a low temperature. More specifically, the refrigerator  1  is equipment to maintain the temperature of a storage chamber at a user&#39;s desired level or less by evaporating and compressing refrigerant repeatedly, in order to store objects at a low temperature. 
     First, the outer appearance of the refrigerator  1  will be described. Referring to  FIGS. 1 and 2 , the refrigerator  1  may include a main body  10 , a plurality of storage chambers  20  and  30  formed inside the main body  10 , and a cooling apparatus (not shown) configured to supply cool air to the storage chambers  20  and  30 . The cooling apparatus may include an evaporator, a compressor, a condenser, and an expander in order to evaporate and compress refrigerant cyclically. 
     Meanwhile, the main body  10  may include an inner case (not shown) forming the storage chambers  20  and  30 , an outer case (not shown) coupled with the outer portion of the inner case and forming the outer appearance of the refrigerator  1 , and an insulator (not shown) disposed between the inner case and the outer case and configured to insulate the storage chambers  20  and  30 . 
     For example, the storage chambers  20  and  30  may be partitioned into a refrigerating chamber  20  which is the upper chamber and a freezing chamber  30  which is the lower chamber, by a partition wall  11 . Meanwhile, the storage chambers  20  and  30  may be disposed vertically, unlike  FIG. 2  in which the storage chambers  20  and  30  are disposed horizontally. That is, the storage chambers  20  and  30  may be disposed in various ways known in the related art. 
     Meanwhile, the refrigerating chamber  20  may be maintained at about 3° C. to keep food refrigerated, and the freezing chamber  30  may be maintained at about −18.5° C. to keep food frozen. In the refrigerating chamber  20 , one or more shelves  23  on which food can be placed, and one or more storage boxes  27  to airtightly store food may be disposed. 
     Meanwhile, the front portions of the refrigerating chamber  20  and the freezing chamber  30  may open to enable a user to put and take food. The opened front portion of the refrigerating chamber  20  may be opened or closed by a pair of rotating doors  21  and  22  hinge-coupled with the main body  10 , and the opened front portion of the freezing chamber  30  may be opened or closed by a sliding door  31  that can slide with respect to the main body  10 . On the rear surfaces of the refrigerating chamber doors  21  and  22 , a door guide  24  may be provided to store food. 
     Also, in the edges of the rear surfaces of the freezing chamber doors  21  and  22 , a gasket  28  may be provided to seal space between the refrigerating chamber doors  21  and  22  and the main body  10  when the refrigerating chamber doors  21  and  22  close so as to prevent cool air from leaking out of the refrigerating chamber  20 . Also, in any one refrigerating chamber door  21  of the refrigerating chamber doors  21  and  22 , a rotating bar  26  may be provided to seal space between the refrigerating chamber doors  21  and  22  when the refrigerating chamber doors  21  and  22  close so as to prevent cool air from leaking out of the refrigerating chamber  20 . 
     Also, an ice-making room  81  for making ice cubes may be provided in the upper corner of the refrigerating chamber  20 . The ice-making room  81  may be partitioned from the refrigerating chamber  20  by an ice-making room wall  82 . 
     The refrigerator  1  may include an ice supply module to discharge ice cubes produced by an ice maker  80  to intake space  91 , an ice-making supply module to control a chute connected to the intake space  91 , and a purified-water supply module  100  to supply water. 
     Referring to  FIG. 3 , in the ice-making room  81 , the ice maker  80  to produce normal ice cubes or carbon-dioxide ice cubes, an ice bucket  83  to store the normal ice cubes or carbon-dioxide ice cubes produced in the ice maker  80 , and an auger  84  to transfer the normal ice cubes or carbon-dioxide ice cubes stored in the ice bucket  83  to the chute  94  may be installed. The ice-making supply module may control operation of producing ice cubes through the above-mentioned components, and discharging the produced ice cubes through the auger  84 . 
     Herein, the normal ice cubes may refer to ice cubes made by freezing normal water containing no carbon dioxide, and the carbon-dioxide ice cubes may refer to ice cubes made by freezing carbon-dioxide water containing carbon-dioxide. Also, the normal water may refer to water purified by the purified-water supply module which will be described later, and the carbon-dioxide water may refer to water containing carbon dioxide. In the following description, normal water and carbon-dioxide water will be collectively referred to as water when they do not need to be distinguished from each other, and also, normal ice cubes and carbon-dioxide ice cubes will be collectively referred to as ice cubes when they do not need to be distinguished from each other. 
     Meanwhile, the refrigerating chamber  20  may include a water tank  70  to store water. The water tank  70  may be located between the plurality of storage boxes  27 , as shown in  FIG. 2 , although not limited to this. However, the water tank  70  may be located at any position inside the refrigerating chamber  20 , as long as it can cool water stored therein through cool air inside the refrigerating chamber  20 . 
     The water tank  70  may be connected to an external water source  40  such as a water pipe, as shown in  FIG. 3 , and store water purified through a purifying filter  50 . Meanwhile, a water supply hose connected to the water tank  70  may include a water valve V. Accordingly, the refrigerator  1  according to an embodiment of the present disclosure may adjust a degree of opening of the water valve V to adjust the amount of water supplied through an outlet  303  via a flow path. Also, the power supply hose may include a flow sensor F to measure the amount of water that is supplied. 
     The purified-water supply module may supply water that is to be discharged through the outlet  212  of a dispenser  90 , or supply water to a carbon-dioxide water supply module for producing carbon-dioxide water. The purified-water supply module may control the water tank  70  to store purified water, a purifying filter  50  to purify water supplied from the external water source  40 , the water valve V to distribute purified water to the ice-making room  81  or the water tank  70  and to adjust the amount of water, and the flow sensor F to measure the amount of water that is to be supplied to the ice maker  80  or the carbon-dioxide water supply module, thereby supplying water. 
     Meanwhile, in any one refrigerating chamber door  21  of the refrigerating chamber doors  21  and  22 , the dispenser  90  may be disposed to enable a user to take water or ice cubes from the outside without opening the refrigerating chamber door  21 . However, the dispenser  90  may be positioned at any other location, instead of the front portion of the refrigerator  1  as shown in  FIG. 1 , as long as it can provide the user with various information visually at the location. 
     The dispenser  90  may include the intake space  91  into which the user can insert a container to fill water or ice cubes in the container, one or more input buttons to enable the user to manipulate various settings of the dispenser  90 , an interface  92  to display various information related to the dispenser  90 , and a lever  93  to operate the dispenser  90  to discharge water or ice cubes. Also, the dispenser  90  may include a container support  95  to support a container to receive water or ice cubes. 
     The container support  95  may be fixed at a predetermined location. Or, the container support  95  may be movable in up, down, left, and right directions. For example, if a container is put on the container support  95 , the refrigerator  1  may control a motor included in the container support  95  to move the container support  95  to a position close to the outlet  212 , thus preventing water or ice cubes discharged from the outlet  212  from splashing out of the container. 
     Also, the container support  95  may fix a container placed thereon to prevent the container from escaping from the container support  95 . For example, a groove may be formed in the upper surface of the container support  95 , and the groove may be formed as an elastic member. Accordingly, if the user inserts a container into the groove, the container can be fixed. 
     Also, the container support  95  may include a motor as described above. Accordingly, if it is sensed that a container is positioned in the groove formed in the container support  95 , the refrigerator  1  may adjust the shape of the container support  95  through the motor so that the container can be fixed in the groove. 
     Meanwhile, as described above, the interface  92  may be disposed on the front portion of the refrigerator  1 . For example, the interface  92  may be implemented as a display. The display may be one of various kinds of displays well-known in the related art, such as a Liquid Crystal Display (LCD), a Light Emitting Diode (LED) display, a Plasma Display Panel (PDP) display, an Organic Light Emitting Diode (OLED) display, a Cathode Ray Tube (CRT) display, or the like, although not limited to these. That is, the interface  92  may be any device that can display a user interface capable of visually displaying various information related to the refrigerator  1  and receiving various control commands from the user. 
     The refrigerator  1  according to an embodiment of the present disclosure may display, on the interface  92 , a user interface configured to receive various control commands related to the refrigerator  1  from the user, as well as providing various information for the user. 
     In the dispenser  90 , the intake space  91  may be formed in an accommodating groove of the refrigerating chamber door  21 . In the intake space  91 , a lever (not shown) that generates a discharge command signal when it is manipulated by a user who intends to take water or ice cubes may be provided. Also, in the dispenser  90 , the outlet  212  may be provided to discharge at least one of water and ice cubes when the lever is manipulated. However, the dispenser  90  may discharge at least one of water and ice cubes when receiving a supply command through the interface  92 . 
     Also, as shown in  FIG. 4 , the dispenser  90  may include an opening/closing module, or outlet cover,  301  to open or close the outlet  212 . 
       FIGS. 5A and 5B  are enlarged views showing the outlet and the opening/closing module of the dispenser. 
     In  FIG. 5A , the outlet  303 , the opening/closing module  301 , and a support member  305  are shown. 
     The opening/closing module  301  may be pivotally coupled with the support member  305  to open or close the outlet  303 . 
       FIG. 5A  shows a state in which the opening/closing module  301  opens. 
     The opening/closing module  301  may include a cap  301   a  and a gasket  301   b . The gasket  301   b  may be formed of, for example, a rubber material to be able to tightly close the outlet  303 . According to embodiments, the opening/closing module  301  may be configured with only the cap  301   a , or with the cap  301   a  and the gasket  301   b  integrated into one body. 
     In  FIG. 5B , the opening/closing module  301 , the support member  305 , and a spring  307  are shown.  FIG. 5B  shows a state in which the opening/closing module  301  closes the outlet  303 . 
     The spring  307  may be installed in the opening/closing module  301  to apply a force in a direction of closing the opening/closing module  301 . The opening/closing module  301  can be maintained in a closed state by the spring  307 . 
       FIG. 6  shows an outlet opening/closing system of opening or closing the outlet of the dispenser in the refrigerator according to an embodiment of the present disclosure. 
     Referring to  FIG. 6 , the outlet opening/closing system may include a driver  320 , a cam  309  rotating with respect to a first axis  319  by the driver  320 , and the opening/closing module  301  pivoting in a direction  322  with respect to a second axis  321  according to the rotation of the cam  309  to open the outlet  303 , wherein the first axis  319  crosses the second axis  321  at a predetermined angle. The predetermined angle may be, for example, in the range of 45 degrees to 135 degrees. Details about the opening/closing module  301 , the support member  305 , and the spring  307  have been described above with reference to  FIGS. 5A and 5B , and accordingly, further descriptions thereof will be omitted. 
     The opening/closing system may include the support member  305 . 
     The opening/closing module  301  may be pivotally coupled with the support member  305  to be able to pivot with respect to the second axis  321 . That is, a hole may be formed in the support member  305 , and a protrusion formed at the upper end of the opening/closing module  301  may be inserted into the hole, so that the opening/closing module  301  can pivot with respect to the second axis  321 . Details about the operation will be described later with reference to  FIG. 16 . 
     The opening/closing module  301  may include a lever  302 . 
     The lever  302  may be integrated into the opening/closing module  301 , or fabricated as a separate member and then attached on the opening/closing module  301 . In one side of the lever  302 , a protrusion may be formed, and the protrusion may include a spherical surface. The protrusion may contact the cam  309 . The spherical surface may minimize a contact area of the protrusion to the cam  309  to thus reduce friction. As the cam  309  rotates, the surface area of the cam  309  contacting the protrusion may change so that the lever  302  can move in a direction that is vertical to the cam surface due to a difference in height of the cam surface. As the lever  302  moves due to the difference in height of the cam surface, the opening/closing module  301  may pivot with respect to the second axis  321 . 
     The lever  302  may be located at the upper area of the opening/closing module  301  with respect to a center line  3015  dividing the opening/closing module  301  in half horizontally. If the lever  302  is attached close to the second axis  321  (also, referred to as a pivot axis  321 ), the opening/closing module  301  can move greatly even when the lever  302  moves a little. Accordingly, it is possible to reduce the maximum height of the cam  309 , which leads to a reduction of the total thickness  317  of the opening/closing system. 
     The cam  309  may rotate in a clockwise direction with respect to the first axis  319  by the driver  320 . The cam  309  may have a shape obtained by cutting a cylinder at a predetermined angle, and include a cam surface. The cam surface may include a surface whose height changes according to the rotation angles of the cam  309  with respect to the first axis  319  as a rotation axis. That is, as the cam  309  rotates, the lever  302  may move in the direction that is vertical to the cam surface, due to the difference in height of the cam surface. 
     The cam  309  may include a first protrusion  313  and a second protrusion  311 . The second protrusion  311  may operate only a second switch module  316 , and the first protrusion  313  may operate both a first switch module  315  and the second switch module  316 . Details about the operation will be described in more detail, later. 
     The opening/closing module  301  may be pivotally coupled with the support member  305  to be able to pivot with respect to the second axis  321 . Also, the driver  320 , the first switch module  315 , and the second switch module  316  may be coupled with the support member  305 . The shape and structure of the support member  305  will be described later with reference to  FIG. 18 . 
     The first switch module  315  and the second switch module  316  will be described in detail with reference to  FIG. 14 , later. 
     The driver  320  may be coupled with the support member  305 , as described above. 
     The driver  320  may include a motor. According to an embodiment, the driver  320  may be a motor. According to an embodiment, the driver  320  may further include a reduction gear (not shown). The cam  309  may be connected directly to the motor or connected to the motor through the reduction gear to rotate. 
     The first axis  319  which is the rotation axis of the cam  309  may be not parallel to the second axis  321  which is the pivot axis of the opening/closing module  301 , and may cross the second axis  321  at a predetermined angle. For example, the first axis  319  may be at right angles to the second axis  321 . 
     More specifically, in order to prevent the diameters of the motor  320  and the cam  309  having a predetermined size or more from influencing the thickness  317  of the opening/closing system, the diameters of the cam  309  and the motor  320  may be disposed on a y-z plane. If the diameters of the cam  309  and the motor  320  are disposed on the y-z plane, the rotation axis  319  of the cam  309  and the motor  320  may cross the pivot axis  321  of the opening/closing module  301  at a predetermined angle. 
     Because the difference in height of the cam surface formed in the cam  309  can move the lever  302  in a direction that is similar to a rotation vector direction of the opening/closing module  301 , the height difference as if it is even small can open the opening/closing module  301  enough. That is, it is possible to reduce the height of the cam  309  directly influencing the difference in height of the cam surface, which leads to a reduction of the total thickness  317  of the opening/closing system, resulting in the slimness of the dispenser  90 . 
       FIG. 7A  is a perspective view of the cam. 
     Referring to  FIG. 7A , the cam  309  may include a plurality of cam surfaces  3091 ,  3093 ,  3095 , and  3097 , and a circumference surface  3098 . On the circumference surface  3098 , the first protrusion  313  and the second protrusion  311  may be formed. The first protrusion  313  and the second protrusion  311  may be formed on the circumference surface  3098  of the cam  309  in such a way to be spaced apart from each other and arranged at a predetermined angle with respect to each other. For example, the first protrusion  313  and the second protrusion  311  may be arranged at 60 degrees with respect to each other, although not limited to this. 
     The cam surfaces  3091 ,  3093 ,  3095 , and  3097  may include a first flat surface  3091 , a first inclined surface  3097 , a second flat surface  3095 , and a second inclined surface  3093 . The first flat surface  3091 , the first inclined surface  3097 , the second flat surface  3095 , and the second inclined surface  3093  may be connected to each other. 
     The first protrusion  313  may be formed on an area of the circumference surface  3098 , adjacent to the first flat surface  3091 . The second protrusion  311  may be formed on another area of the circumference surface  3098 , adjacent to the first inclined surface  3097 . 
     The first flat surface  3091  may be at a highest height from the bottom surface of the cam  309 , and the second flat surface  3095  may be at a lowest height from the bottom surface of the cam  309 . That is, there is a height difference between the first flat surface  3091  and the second flat surface  3095 . 
     In order to move the lever  302  to the upper surface of the cam  309  with a small force and smoothly move the lever  302  to the lower surface of the cam  309 , while reducing the circumference of the cam  309 , the first inclined surface  3097  and the second inclined surface  3093  may have predetermined angles. For example, the first inclined surface  3097  may have a gradient of about 40 degrees with respect to the bottom surface of the cam  309 , and the second inclined surface  3093  may have a gradient of about 30 degrees with respect to the bottom surface of the cam  309 . 
     The length  3131  of the first protrusion  313  may be relatively longer than the length  3111  of the second protrusion  311 . The first protrusion  313  may contact a first switch lever ( 3151  of  FIG. 8 ) and a second switch lever ( 3161  of  FIG. 8 ) to operate the first switch module  315  and the second switch module  316 . The second protrusion  311  may contact the second switch lever to operate the second switch module  316 . 
     Depending on an angle to which the cam  309  rotates in the clockwise direction, the first protrusion  313  may contact the first switch lever and the second switch lever, or the second protrusion  311  may contact the second switch lever. 
       FIG. 7B  is a top view of the cam. 
     In  FIG. 7B , the cam surfaces  3091 ,  3097 ,  3095 , and  3093  are shown. The cam surfaces  3091 ,  3097 ,  3095 , and  3093  may include the first flat surface  3091 , the first inclined surface  3097 , the second flat surface  3095 , and the second inclined surface  3093 , as described above. The first flat surface  3091 , the second inclined surface  3097 , the second flat surface  3095 , and the second inclined surface  3093  may be connected to each other. 
     The height of the first inclined surface  3097  may increase gradually along a circumferential direction  3097   d . Also, the height of the first inclined surface  3097  may increase gradually along a center direction  3097   c . That is, the height of the first inclined surface  3097  may change along the circumferential direction  3097   d  and along the center direction  3097   c.    
     The height of the second inclined surface  3093  may decrease gradually along the circumferential direction  3093   d . Also, the height of the second inclined surface  3093  may increase gradually along the center direction  3093   c . The height of the second inclined surface  3093  may change along the circumferential direction  3093   d  and along the center direction  3093   c .  FIG. 7C  shows the right side of the cam. 
     In  FIG. 7C , the first inclined surface  3097  is shown. 
     As described above, the height of the first inclined surface  3097  may change along the center direction ( 3097   c  of  FIG. 7B ). An angle  3097   a  of the outer edge of the first inclined surface  3097  may be lower than an angle  3097   b  of the inner edge of the first inclined surface  3097 . Accordingly, the height of the first inclined surface  3071  may change along the center direction ( 3097   c  of  FIG. 7B ). 
       FIG. 7D  shows the left side of the cam. 
     In  FIG. 7D , the second inclined surface  3093  is shown. 
     As described above, the height of the second inclined surface  3093  may change along the center direction ( 3093   c  of  FIG. 7B ). An angle  3093   a  of the outer edge of the second inclined surface  3093  may be lower than an angle  3093   b  of the inner edge of the second inclined surface  3093 . Accordingly, the height of the second inclined surface  3093  may change along the center direction ( 3093   c  of  FIG. 7B ). 
       FIG. 8  shows a state in which the opening/closing module is closed. 
     In  FIG. 8 , the opening/closing module  301 , the spring  307 , the lever  302 , the cam  309 , the driver  320 , the first switch module  315 , the second switch module  316 , the first switch lever  3151 , and the second switch lever  3161  are shown. 
     The lever  302  formed on one surface of the opening/closing module  301  may contact the second flat surface  3095  of the cam  309 , and can close the outlet. The spring  307  may provide a force to the opening/closing module  301  in the direction in which the opening/closing module  301  closes the outlet. That is, when the protrusion of the lever  302  contacts the second flat surface  3095  located at the lowest height of the cam  309 , the opening/closing module  301  may maintain a state in which it closes the outlet. That is, the second flat surface  3095  may maintain the opening/closing module  301  in a closed state for a predetermined time period although the cam  309  rotates. 
     Meanwhile, if the cam  309  rotates in the clockwise direction  310  with respect to the first axis  319  by the driver  320 , a contact point at which the protrusion of the lever  302  contacts the cam  309  may move along the first inclined surface  3097 , and accordingly, the opening/closing module  301  may pivot with respect to the second axis  321  to open the outlet. 
     Meanwhile, the first switch module  315  and the second switch module  316  may provide information about the rotation state of the cam  309 . 
     The first switch module  315  may include the first switch lever  3151 . 
     The second switch module  316  may include the second switch lever  3161 . 
     If the driver  320  rotates, the cam  309  may rotate so that the first protrusion ( 313  of  FIG. 7A ) formed on the circumference surface of the cam  309  may press the first switch lever  3151  and the second switch lever  3161 , and accordingly, the driver  320  may stop rotating. 
     Also, if the driver  320  rotates, the cam  309  may rotate so that the second protrusion ( 311  of  FIG. 7A ) formed on the circumference surface of the cam  309  may also press the second switch lever  3161 , and accordingly, the driver  320  may stop rotating. 
     For example, if a user presses an ice button through the interface in the state that the opening/closing module  301  closes the outlet, the driver  320  may rotate to open the outlet. More specifically, the driver  320  may rotate to rotate the cam  309 , and if the cam  309  rotates, the second protrusion  311  may press the second switch lever  316 . 
     Accordingly, the driver  320  may stop when the protrusion of the lever  302  arrives at the first flat surface  3091 , so that the opening/closing module  301  can be maintained in a state in which it is maximally opened. 
       FIG. 9  shows an opened state of the opening/closing module. 
     In  FIG. 9 , the opening/closing module  301 , the spring  327 , the lever  302 , the cam  309 , and the driver  320  are shown. 
     The lever  302  formed on one surface of the opening/closing module  301  may include a protrusion  3021 . The protrusion  3021  of the lever  302  may contact the cam surface, and may be in the shape of a hemisphere including a spherical surface in order to minimize friction with the cam surface, although not limited to this. 
     If the protrusion  3021  of the lever  302  contacts the first flat surface  3091  of the cam  309 , the lever  302  may contact the cam  309  at the highest position of the cam  309 , and accordingly, the opening/closing module  301  may pivot to a maximum displacement with respect to the second axis  321  to open the outlet maximally. Meanwhile, the spring  327  may provide a force to the opening/closing module  301  in the direction of closing the opening/closing module  301 . While the protrusion  3021  of the lever  302  contacts the first flat surface  3091 , the opening/closing module  301  can be maintained in the state in which it is maximally opened. That is, the first flat surface  3091  can maintain the opening/closing module  301  in the maximally opened state for a predetermined time period although the cam  309  rotates. 
     Meanwhile, as the cam  309  rotates in the clockwise direction  310  with respect to the first axis  319  by the driver  320 , the protrusion  3021  of the lever  302  may move along the second inclined surface  3093  of the cam  309 , and accordingly, the opening/closing module  301  may pivot with respect to the second axis  321  to close the outlet. 
     If the user presses the button again when operation of discharging ice cubes terminates, the driver  320  may rotate, and the lever  302  of the opening/closing module  301  may move in contact with the second inclined surface  3093  of the cam  309  so that the opening/closing module  301  closes the outlet. 
     If the cam  309  continues to rotate, the lever  302  of the opening/closing module  301  may contact the second flat surface  3095  of the cam  309 , the first protrusion ( 313  of  FIG. 7A ) formed on the circumference surface of the cam  309  may press the first switch lever  3151  and the second switch lever  3161 , and the driver  320  may stop rotating when the protrusion  3021  of the lever  302  arrives at the second flat surface  3095 . Accordingly, the opening/closing module  301  may close the outlet, and be maintained in the closed state. The first protrusion ( 313  of  FIG. 7A ) may be formed on the circumference surface of the cam  309 , which is opposite to the first flat surface  3095 . 
     Meanwhile, as described above with reference to  FIGS. 8 and 9 , while the cam  309  rotates one time, the opening/closing module  301  may pivot from the closed state to the opened state and then again pivot to the closed state. 
       FIG. 10  shows a rotation vector direction of the opening/closing module and vertical vector directions of the cam surfaces. 
     In  FIG. 10 , the opening/closing module  301  and the cam  309  are shown. The opening/closing module  301  may pivot by the movement of the lever  302  contacting the cam  309  when the cam  309  rotates. More specifically, when the opening/closing module  301  pivots in the direction of closing the outlet by the force of the spring  307 , the rotation vector directions of the opening/closing module  301  may be the directions  1002 ,  1003 , and  1004  of the tangents of an imaginary circle  1001 . 
     Meanwhile, when the opening/closing module  301  pivots in the direction of opening the outlet by the cam  309 , the rotation vector directions of the opening/closing module  301  may be the directions  1005 ,  1006 , and  1007  of the tangents of the imaginary circle  1001 , which are similar to the movement direction (that is, a direction  1010  that is vertical to the cam surface) of the lever  302 . That is, the cam surfaces of the cam  309  may be formed to move the lever  302  in the directions  1005 ,  1006 , and  1007  of the tangents of the imaginary circle  1001 . 
     That is, because the cam surfaces are at different heights in the circumferential direction and in the center direction, the lever  302  contacting the cam surfaces may move in the vertical vector direction  1010  of the cam surfaces when the cam  309  rotates, and the opening/closing module  301  may pivot. 
     Meanwhile, the movement direction of the lever  302  may be the vertical vector direction  1010  of the cam surfaces, and the vertical vector direction  1010  may be similar to the rotation vector directions  1005 ,  1006 , and  1007  of the opening/closing module  301  that pivots when the opening/closing module  301  is opened, so that the opening/closing module  301  can operate with a small output from the driver  320 . 
       FIGS. 11 and 12  show a state in which the cam contacts the first switch lever and the second switch lever when the opening/closing module is in an opened state. 
     In  FIG. 11 , the opening/closing module  301 , the lever  302 , the cam  309 , the first switch lever  3151 , and the second switch lever  3161  are shown. 
     The first switch lever  3151  may turn on the first switch module  315 , and the second switch lever  3161  may turn on the second switch module  316 . 
     If the cam  302  contacts the first flat surface  3091  of the cam  309 , the opening/closing module  301  may open the outlet  303  maximally. At this time, the first switch lever  3151  and the second switch lever  3161  may not contact the protrusion of the cam  309 , and accordingly, the first switch module  315  and the second switch module  316  may be maintained in a turned-off state. Because the first switch module  315  and the second switch module  316  are maintained in the turned-off state, the cam  309  can continue to rotate in the clockwise direction. 
     In  FIG. 12 , the opening/closing module  301 , the lever  302 , the cam  309 , the first switch lever  3151 , and the second switch lever  3161  are shown. 
     If the cam  309  rotates in the clockwise direction from the state of  FIG. 11 , the second protrusion  311  may contact the second switch lever  3161  to turn on the second switch module  316 . Meanwhile, because the first switch lever  3151  does not contact the second protrusion  311 , the first switch module  315  may be maintained in a turned-off state, so that the opening/closing module  301  is maintained in the opened state. 
       FIG. 13  shows a state in which the cam contacts the first switch lever and the second switch lever when the opening/closing module is in a closed state. 
     In  FIG. 13 , the opening/closing module  301 , the lever  302 , the cam  309 , the first switch lever  3151 , and the second switch lever  3161  are shown. 
     If the lever  302  contacts the second flat surface  3095  of the cam  309 , the opening/closing module  301  may close the outlet  303 . At this time, the first switch lever  3151  and the second switch lever  3161  may contact the first protrusion  313  of the cam  309 . Accordingly, the first switch module  315  and the second switch module  316  may be maintained in the turned-on state, and the opening/closing module  301  may be maintained in the closed state. 
       FIG. 14  shows the first switch module and the second switch module. 
     The first switch module  315  may include a first switch button  3153  and the first switch lever  3151 . The first switch lever  3151  may be formed of an elastic material. When the first switch lever  3151  contacts the first protrusion  313  of the cam  309 , the first switch lever  3151  may operate the first switch button  3153 . 
     The second switch module  316  may include a second switch button  3163  and the second switch lever  3161 . The second switch lever  3161  may be formed of an elastic material. When the second switch lever  3161  contacts the first protrusion  313  and the second protrusion  311  of the cam  309 , the second switch lever  3161  may operate the second switch button  3163 . 
       FIG. 15  is a perspective view of an opening/closing system according to an embodiment of the present disclosure. 
     In  FIG. 15 , an opening/closing module  401 , a lever  402 , a support member  405 , a spring  407 , a cam  409 , and a driver  420  are shown. 
     Details about the opening/closing module  401 , the lever  402 , the support member  405 , the spring  407 , the cam  409 , and the driver  420  have been described above with reference to  FIGS. 5A, 5B, and 6 , and accordingly, further descriptions thereof will be omitted. 
     The cam  409  and the driver  420  may be disposed to the left of the opening/closing module  401 . Accordingly, the lever  402  contacting the cam  409  may be disposed at the left upper portion of the opening/closing module  401 . 
       FIG. 16  is a top view of the opening/closing system according to an embodiment of the present disclosure. 
     In  FIG. 16 , the opening/closing module  401 , the lever  402 , the spring  407 , the cam  409 , and a support member  405  are shown. 
     The opening/closing module  401  may include a cap  401   a  and a gasket  401   b . The gasket  401   b  may be formed of a soft rubber material. One end of the spring  407  may be connected to the center portion of the cap  401   a  to apply a force in the direction of closing the outlet  303 . 
     In a first side of the upper end of the cap  401   a , a first protrusion  4011  may be formed. The first protrusion  4011  may be inserted into a first hole  4051  formed in the support member  405  in such a way to be rotatable in the first hole  4051 . The diameter of the first hole  4051  may be larger than that of the first protrusion  4011 . 
     In a second side of the upper end of the cap  401   a , a second protrusion  4012  may be formed. The second protrusion  4012  may be inserted into a second hole  4052  formed in the support member  405  in such a way to be rotatable in the second hole  4052 . The diameter of the second hole  4052  may be larger than that of the second protrusion  4012 . 
     Because the first protrusion  4011  and the second protrusion  4012  of the cap  401   a  are rotatably coupled with the support member  405 , the opening/closing module  401  can pivot with respect to an axis  421 . 
     The cam  409  may be disposed to the left of the opening/closing module  401 , and the lever  402  may contact the cam  409 . If the cam  409  rotates, the height of the cam surface which the lever  402  contacts may change to move the lever  402  in the direction that is vertical to the cam surface. Accordingly, the opening/closing module  401  may pivot with respect to the axis  421 . 
     The lever  402  may be disposed in the left upper portion of the opening/closing module  401  with respect to the center of the opening/closing module  401 . 
       FIG. 17  is a front view of the opening/closing system according to an embodiment of the present disclosure. 
     In  FIG. 17 , the opening/closing module  401 , the lever  402 , the support member  405 , the cam  409 , the driver  420 , a first switch module  415 , and a second switch module  416  are shown. The functions of the individual components have been described above, and accordingly, further descriptions thereof will be omitted. 
     The cam  409 , the driver  420 , the first switch module  415 , and the second switch module  416  may be disposed to the left of the opening/closing module  401 . 
     The lever  402  may contact the cam  409 , and when the cam  409  rotates, the lever  402  may move in a y-axis direction to pivot the opening/closing module  401 . 
     A portion  4021  of the lever  402  contacting the cam  409  may be a spherical surface in order to minimize a friction force. Meanwhile, the lever  402  may include no protrusion, unlike the lever  302  of  FIG. 9 . 
     That is, the lever  402  may directly contact the cam surfaces of the cam  409  without having any protrusion. 
       FIG. 18  is a perspective view of the support member of the opening/closing system according to an embodiment of the present disclosure. 
     Referring to  FIG. 18 , the support member  405  may include a first hole  4051  and a second hole  4052  to rotatably support the opening/closing module  401 , a first housing  4054  to accommodate the driver  420 , and a second housing  4053  to accommodate the first switch module  415  and the second switch module  416 . 
       FIG. 19  is a perspective view of the cam used in the opening/closing system according to an embodiment of the present disclosure. 
     Referring to  FIG. 19 , the cam  409  may include a plurality of cam surfaces  4091 ,  4093 ,  4095 , and  4097 , a first protrusion  413 , and a second protrusion  411 . The first protrusion  413  and the second protrusion  411  may be formed on the circumference surface of the cam  409  in such a way to be spaced apart from each other and arranged at a predetermined angle with respect to each other. 
     The functions of the individual components have been described above with reference to  FIGS. 7A to 7D , and further descriptions thereof will be omitted. 
     The length of the first protrusion  413  may be relatively longer than that of the second protrusion  411 . The first protrusion  413  may contact a first switch lever and a second switch lever to operate the first switch module  415  and the second module  416 . The second protrusion  411  may contact the second switch lever to operate the second switch module. 
     Depending on an angle to which the cam  409  rotates, the first protrusion  413  may contact the first switch lever and the second switch lever, or the second protrusion  411  may contact the second switch lever. 
       FIG. 20A  shows the outer appearance of the door of a refrigerator according to an embodiment of the present disclosure. 
     Referring to  FIG. 20A , a refrigerator door  2000  may include a door plate  2001 , a cover  2003 , and intake space  2005 . 
     In the inside of the cover  2003 , an opening/closing system ( 2011  of  FIG. 20B ) may be installed. The cover  2003  may be integrated into the door plate  2001 . When a slim opening/closing system is used, the opening/closing system may be inserted into the inside of the cover  2003  in the direction of an arrow  2007  (up from the bottom of the cover  2003 ) through the intake space  2005 . 
     If the cover  2003  is integrated into the door plate  2001 , borders between the cover  2003  and the door plate  2001  can be removed, which improves the beauty and simplifies the door assembly process, resulting in high productivity. 
       FIG. 20B  shows the internal structure of the refrigerator door shown in  FIG. 20A . 
     In  FIG. 20B , the opening/closing system  2011  is shown. The opening/closing system  2001  may be installed in the inside of the cover  2003  shown in  FIG. 20A . 
       FIG. 20C  is a projected view showing a portion (a portion surrounded by dotted lines  2009  of  FIG. 20A ) of a refrigerator door according to an embodiment of the present disclosure. 
     Referring to  FIG. 20C , the opening/closing system  2011  may be installed in the inside of the cover  2003  integrated into the door plate  2001 . 
     When a slim opening/closing system  2011  is used, the opening/closing module  2001  may be inserted into the inside of the cover  2003  through the intake space  2005 . 
     In the opening/closing system according to the embodiment of the present disclosure, because the cam and motor are disposed such that the rotation axis of the cam and motor crosses the pivot axis of the opening/closing module at a predetermined angle, the diameters of the motor and cam do not influence the thickness of the opening/closing system, which contributes to the slimness of the opening/closing system. 
     Configurations illustrated in the embodiments and the drawings described in the present specification are only the preferred embodiments of the present disclosure, and thus it is to be understood that various modified examples, which may replace the embodiments and the drawings described in the present specification, are possible when filing the present application. 
     The terms used in the present specification are used to describe the embodiments of the present disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention is provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents. It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. It will be understood that when the terms “includes,” “comprises,” “including,” and/or “comprising,” when used in this specification, specify the presence of stated features, figures, steps, components, or combination thereof, but do not preclude the presence or addition of one or more other features, figures, steps, components, members, or combinations thereof. 
     It will be understood that, although the terms first, second, etc. may be used herein to describe various components, these components should not be limited by these terms. These terms are only used to distinguish one component from another. For example, a first component could be termed a second component, and, similarly, a second component could be termed a first component, without departing from the scope of the present disclosure. As used herein, the term “and/or” includes any and all combinations of one or more of associated listed items. 
     As used herein, the terms “unit”, “device, “block”, “member”, or “module” refers to a unit that can perform at least one function or operation. 
     Although a few embodiments of the present disclosure have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.