Abstract:
An ice-making device of a refrigerator includes: an ice-making unit installed within a refrigerator and making ice cubes; a dispenser provided on a refrigerator door to allow the ice cubes to be taken out of the refrigerator; an ice duct guiding the ice cubes made in the ice-making unit to the dispenser; and an introduction preventing unit preventing an object from being introduced into the ice-making unit through the ice duct. A method for controlling an ice-making device of a refrigerator includes: inputting an ice cube extract signal; making ice cubes by driving an ice-making unit provided within the refrigerator and breaking the ice cubes according to the inputted signal; sensing an internal temperature of an ice duct that guides the ice cubes made in the ice-making unit to a dispenser provided on a refrigerator door; and stopping an operation of the ice-making unit when the sensed temperature is higher. Because an introduction of an external object into the ice duct is prevented and the operation of the ice-making unit is stopped, the external object can be prevented from being damaged, so the user can stably use the ice-making device of the refrigerator.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims priority under 35 U.S.C. §119 to Korean Patent Application No. 2006-38930, filed in korea on Apr. 28, 2006, Korean Patent Application No. 2006-48746, filed in korea on May 30, 2006, Korean Patent Application No. 2006-48747, filed in Korea on May 30, 2006, and Korean Patent Application No. 2006-62188, filed in korea on Jul. 3, 2006, the entirety of which are hereby incorporated by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to an ice-making device of a refrigerator and, more particularly, to an ice-making device of a refrigerator adapted for being stably used by users and a control method thereof. 
         [0004]    2. Description of the Related Art 
         [0005]    Refrigerators recently on the markets include an ice-making unit for making ice cubes within a freezing chamber. Ice cubes made in the ice-making unit are transferred to a dispenser that selectively opens and closes the freezing chamber, and taken out according to a user selection. 
         [0006]    In general, the refrigerator body includes the freezing chamber for keeping food items in storage within the main body. The freezing chamber is selectively opened and closed by its door. A rear protrusion is provided on a rear surface of the door. A dispenser for taking out water or ice cubes is provided one side of a front surface of the door. 
         [0007]    A water supply pipe is led in to an upper portion of the refrigerating chamber. An ice-making unit is provided at an upper portion of the freezing chamber in order to receive water from the water supply pipe and make ice cubes. An ice bank for storing ice cubes made in the ice-making unit is provided at a lower side of the ice-making unit. 
         [0008]    A screw for transferring stored ice cubes to a front end portion of the ice bank is provided within the ice bank. 
         [0009]    An ice separating unit is provided at a front side of the ice bank. The ice separating unit is connected with a front end of the screw and separates or crushes ice cubes transferred by the screw to the front end of the ice bank to a certain size. 
         [0010]    The ice cubes separated by the ice separating unit is guided to the dispenser by an ice duct to allow a user to taken out the ice cubes or water. 
         [0011]    However, the related art ice-making device of the refrigerator has the following problems. That is, one end portion of the ice duct is connected with the dispenser in order to guide the separated ice cubes to the dispenser. Thus, an object can be introduced into the ice-making unit through the dispenser, so the introduced object can be damaged or the ice-making unit can be damaged. 
       SUMMARY OF THE INVENTION 
       [0012]    Therefore, in order to address the above matters, the various features described herein have been conceived. One aspect of the exemplary embodiments is to provide an ice-making device of a refrigerator adapted for being stably used by users and a control method thereof. 
         [0013]    This specification provides an ice-making device of a refrigerator that may include: an ice-making unit that is installed within a refrigerator and making ice cubes; a dispenser that is provided on a refrigerator door to allow the ice cubes to be taken out of the refrigerator; an ice duct that guides the ice cubes made in the ice-making unit to the dispenser; and an introduction preventing unit that prevents an object from being introduced into the ice-making unit through the ice duct. 
         [0014]    This specification also provides an ice-making device of a refrigerator that may include: an ice-making unit that is installed within a refrigerator and making ice cubes; a dispenser that is provided on a refrigerator door to allow the ice cubes to be taken out of the refrigerator; and a bent ice duct that guides ice cubes made in the ice-making unit to the dispenser and prevents an introduction of an object through the dispenser. 
         [0015]    This specification also provides an ice-making device of a refrigerator that may include: an ice-making unit that is installed within a refrigerator and makes ice cubes; a dispenser that is provided on a refrigerator door to allow the ice cubes to be taken out of the refrigerator; an ice duct that guides the ice cubes made in the ice-making unit to the dispenser; a sensor that senses an introduction of an object into the ice duct through the dispenser; and a control unit that stops an operation of the ice-making unit when an introduction of an object is sensed by the sensor. 
         [0016]    This specification also provides a method for controlling an ice-making device of a refrigerator that may include: inputting an ice cube extract signal; making ice cubes by driving an ice-making unit provided within the refrigerator according to the inputted signal and breaking the ice cubes; and controlling an opening degree of an ice duct that connects the ice-making unit and a dispenser provided on a refrigerator door according to a state of the ice cubes. 
         [0017]    The opening degree of the ice duct can be controlled by controlling a rotation angle of an opening and closing member that combined with a hinge shaft combined at one side of the ice duct and opens and closes an internal passage of the ice duct. 
         [0018]    The method for controlling an ice-making device of a refrigerator may further include: sensing a rotation angle of the opening and closing member; and stopping an operation of the ice-making unit when the sensed rotation angle is greater than a pre-set angle. 
         [0019]    This specification also provides a method for controlling an ice-making device of a refrigerator that may include: inputting an ice cube extract signal; making ice cubes by driving an ice-making unit provided within the refrigerator and breaking the ice cubes according to the inputted signal; sensing an internal temperature of an ice duct that guides the ice cubes made in the ice-making unit to a dispenser provided on a refrigerator door; and stopping an operation of the ice-making unit when the sensed temperature is higher than a pre-set temperature level. 
         [0020]    With such constructions, the ice-making device of a refrigerator and its control method can prevent an object from being introduced into the ice duct and prevent the object from being damaged by stopping the operation of the ice-making unit. 
         [0021]    The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]    The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description served to explain the principles of the invention. 
           [0023]    In the drawings: 
           [0024]      FIG. 1  is a view illustrating an ice-making device of a refrigerator according to a first exemplary embodiment of the present invention; 
           [0025]      FIG. 2  is an enlarged view of a rotary discharge member in  FIG. 1 ; 
           [0026]      FIG. 3  is a view illustrating an ice-making device of a refrigerator according to a second exemplary embodiment of the present invention; 
           [0027]      FIG. 4  is a view illustrating an ice-making device of a refrigerator according to a third exemplary embodiment of the present invention; 
           [0028]      FIG. 5  is a view illustrating an ice-making device of a refrigerator according to a fourth exemplary embodiment of the present invention; 
           [0029]      FIG. 6  is a view illustrating an ice-making device of a refrigerator according to a fifth exemplary embodiment of the present invention; 
           [0030]      FIG. 7  is a view illustrating an ice-making device of a refrigerator according to a sixth exemplary embodiment of the present invention; 
           [0031]      FIG. 8  is an enlarged view of a door basket; 
           [0032]      FIG. 9  is a view illustrating an ice-making device of a refrigerator according to a seventh exemplary embodiment of the present invention; 
           [0033]      FIG. 10  is an enlarged view of an opening and closing member in  FIG. 9 ; 
           [0034]      FIG. 11  is a flow chart illustrating the processes of a method for controlling an ice-making device of a refrigerator in  FIG. 9 ; 
           [0035]      FIG. 12  is a view illustrating an ice-making device of a refrigerator according to an eighth exemplary embodiment of the present invention; and 
           [0036]      FIG. 13  is a flow chart illustrating the processes of a method for controlling an ice-making device of a refrigerator in  FIG. 12 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0037]    The ice-making device of a refrigerator according to the first exemplary embodiment of the present invention will now be described with reference to the accompanying drawings.  FIG. 1  is a view illustrating an ice-making device of a refrigerator according to a first exemplary embodiment of the present invention, and  FIG. 2  is an enlarged view of a rotary discharge member in  FIG. 1 . 
         [0038]    With reference to  FIGS. 1 and 2 , a freezing chamber  153  is provided within a refrigerator body  151 . Food items are kept in storage in the freezing chamber  153 . The freezing chamber  153  is selectively opened and closed by a door  155 . The door  155  is installed at one side of the main body  151  such that the other end portion there of is rotatable in a forward and backward direction centering around one end thereof. 
         [0039]    A rear protrusion  156  is provided on a rear surface of the door  155 . The rear protrusion  156  is formed as a portion of a door liner forming the rear surface is horizontally protruded toward the rear side of the door  155 . 
         [0040]    A dispenser  157  is provided at one side of a front surface of the door  155 . The dispenser  157  allows a user to take water or ice cubes out of it without opening the door  155 . 
         [0041]    A water supply pipe  159  is led in to an upper portion of the refrigerating chamber  153 . The water supply pipe  159  supplies water for making ice cubes in an ice-making unit  161  (to be described). A heater  159   h  is provided on an outer circumferential surface of the water supply pipe  159 . The heater  159   h  heats at a certain temperature to prevent the water supply pipe  159  from being frozen. 
         [0042]    The ice-making unit  161  is installed at an upper portion of the freezing chamber  153 . The ice-making unit  161  makes ice cubes, separates or crushes them into certain size, and transfers the separated ice cubes to the dispenser  157 . The ice-making unit  161  is controlled by a controller (not shown). 
         [0043]    The ice-making unit  161  includes an ice maker  163 . The ice maker  163  receives water from the water supply pipe  159  and substantially makes ice cubes. An ice bank  164  is installed at a lower side of the ice maker  163 . The ice bank  164  stores ice cubes made in the ice maker  163 . 
         [0044]    A screw  165  is provided within the ice bank  164 . The screw  165  transfers the ice cubes stored in the ice bank  164  toward a front side of the ice bank  161 , namely, toward an ice separating unit  168  (to be described). 
         [0045]    A motor  166  is installed at a rear side of the ice bank  164 . The motor  166  provides a driving force for rotating the screw  165  and the ice separating unit  168 . A gear box  167  is provided between the rear surface of the ice bank  164  and the motor  166 . The gear box  167  includes a plurality of gears for increasing a driving torque by reducing the driving force of the motor  166 . 
         [0046]    The ice separating unit  168  is provided at a front side of the ice bank  164 . The ice separating unit  168  separates or crushes ice cubes transferred by the screw  165  into a certain size. The ice separating unit  168  is connected with a front end of the screw  165  and rotated by a driving force of the motor  166 . 
         [0047]    An ice duct  169  is provided to guide the ice cubes broken by the ice separating unit  168  to the dispenser  157 . The ice duct  169  has a tubular shape with a certain sectional area and is penetratingly installed at the door  155 . The section of the ice duct  169  may have a square or rectangular shape. The ice duct  169  extends slantingly in a downward direction at a certain angle toward the dispenser  157  from the ice-making unit  161 . Namely, the ice duct  169  is installed to penetrate the door  155  so as to be positioned near the ice-making unit  161 , substantially, such that both end portions thereof are adjacent to the lower side of the ice separating unit  168  and the dispenser  157 . 
         [0048]    A rotatable discharge member  171  is rotatably installed within the ice duct  169 . The rotatable discharge member  171  selectively opens and closes the interior of the ice duct  169  only when ice cubes are transferred to the dispenser  157  by the ice duct  169 . For this purpose, the rotatable discharge member  171  includes a hub portion  173  and multiple blades  175 ,  177  and  179 . 
         [0049]    The hub portion  173  has a hollow cylindrical shape with a certain length. A through hole  173   a  is formed long in a lengthwise direction within the hub portion  173 . A rotational shaft  174  is inserted in the through hole  173   a  formed within the ice duct  169 . Accordingly, the hub portion  173  is rotatable centering around the rotational shaft  174 . 
         [0050]    The blades  175 ,  177  and  179  extend radially from an outer circumferential surface of the hub portion  173 . The blades  175 ,  177  and  179  refer to first, second and third blades  175 ,  177  and  179  which are separated by an angle of 120°, respectively on the outer circumferential surface of the hub portion  173 . When the hub portion  173  is rotated centering around the rotational shaft  174 , the interior of the ice duct  169  is substantially opened and closed by the mutually adjacent first, second and third blades, namely, by the first and second blades  175  and  177 , by the second and third blades  177  and  179 , and the third and first blades  179  and  175 . 
         [0051]    The operation of the ice-making device of a refrigerator according to the first exemplary embodiment of the present invention will now be described in detail. 
         [0052]    First, when the user manipulates the dispenser  157 , ice cubes stored in the ice bank  164  after being made in the ice maker  163  are transferred to the front end of the ice bank  164  by the screw  165 . The ice cubes transferred to the front end of the ice bank  164  are separated by the ice separating unit  168 . The ice cubes separated by the ice separating unit  168  are transferred to the dispenser  157  through the ice duct  169  and then taken out. 
         [0053]    At this time, the interior of the ice duct  169  is closed by the rotatable discharge member  171 . And as the rotatable discharge member  171  is rotated by the ice cubes transferred through the ice duct  169  to the dispenser  157 , the interior of the ice duct  169  is opened. 
         [0054]    In detail, in a state that, for example, the ice duct  169  is closed by the first and second blades  175  and  177 , ice cubes transferred to the dispenser  157  through the ice duct  169  push the first blade  175  that closes the interior of the ice duct  169 . Then, the hub portion  173  is rotated centering around the rotational shaft  174 , and the interior of the ice duct  169  closed by the first and second blades  175  and  177  starts to be opened. And when the hub portion  173  is continuously rotated centering around the rotational shaft  174 , the interior of the ice duct  169  starts to be closed by the second and third blades  177  and  179 . In this manner, the interior of the ice duct is continuously opened and closed by the rotatable discharge member  171 . 
         [0055]    Meanwhile, an object may be introduced to one end portion of the ice duct  169  communicating with one side of an upper portion of the dispenser  157 . In this case, because the interior of the ice duct  169  is closed by the rotatable discharge member  171 , the object cannot pass through the ice duct  169 . Thus, a phenomenon that the object contacts with the ice separating unit  168  through the ice duct  169  and is damaged or the ice separating unit  168  is damaged can be prevented. 
         [0056]    In a state that ice cubes are not supplied to outside through the dispenser  169 , the ice duct  169  is closed by the rotatable discharge member  171 . Thus, a phenomenon that cooling air at the inner side of the freezing chamber  153  is leaked through the ice duct  169  can be minimized. 
         [0057]    An ice-making device of a refrigerator according to a second exemplary embodiment of the present invention will now be described with reference to the accompanying drawings. The construction of an ice-making unit  261  for making and separating or crushing ice cubes and the construction for supplying the ice cubes to a dispenser  257  are the same as those in the first exemplary embodiment of the present invention, so a detailed description therefor will be omitted. 
         [0058]      FIG. 3  is a view illustrating an ice-making device of a refrigerator according to a second exemplary embodiment of the present invention. 
         [0059]    With reference to  FIG. 3 , an ice duct  271  extends in a rounded form with a certain radius of curvature toward the dispenser  257  from the ice-making unit  261 . In this case, the ice duct  271  can extend to be rounded with an increased slope as it goes farther toward the dispenser  257 . 
         [0060]    In more detail, the ice duct  271  is formed to extend in a rounded manner such that one end portion thereof penetrates one side of a rear surface of a door  255  corresponding to a right lower portion of the ice separating unit  268  and as it goes toward the dispenser  257 , its slope increases and the other end portion thereof penetrates one side of a front surface of the door  255  corresponding to one side of an upper portion of the dispenser  257 . The reason for the ice duct  271  to extend with the increased slope toward the dispenser  257  at the right lower side of the ice separating unit  268  is to allow separated ice cubes to be smoothly transferred to the dispenser  257  according to their self-weight. 
         [0061]    The operation of the ice-making device of a refrigerator according to the second exemplary embodiment of the present invention will now be described. 
         [0062]    First, when a user manipulates the dispenser  257 , the ice cubes stored in the ice bank  264  after being made in an ice maker  263  are transferred to the front end of the ice bank  264  by a screw  265 . The ice cubes transferred to the front end of the ice bank  264  are separated by the ice separating unit. The separated ice cubes by the ice separating unit are transferred to the dispenser  257  through the ice duct  271  and then taken out. 
         [0063]    Meanwhile, an object may be introduced to one end portion of the ice duct  269  communicating with one side of an upper portion of the dispenser  257 . In this case, because the ice duct  271  extends in the rounded shape with a certain radius of curvature, the object cannot pass through the ice duct  271 . Thus, a phenomenon that the object contacts with the ice separating unit  268  through the ice duct  271  and is damaged or the ice separating unit  268  is damaged can be prevented. 
         [0064]    An ice-making device of a refrigerator according to a third exemplary embodiment of the present invention will now be described with reference to the accompanying drawings. The construction of an ice-making unit  361  for making and separating or crushing ice cubes and the construction for supplying the ice cubes to a dispenser  357  are the same as those in the first exemplary embodiment of the present invention, so a detailed description therefor will be omitted. 
         [0065]      FIG. 4  is a view illustrating an ice-making device of a refrigerator according to a third exemplary embodiment of the present invention. 
         [0066]    With reference to  FIG. 4 , the ice duct  373  extends at different angles toward the dispenser  357  from the ice-making unit  361  and penetrates the door  355 . In this case, the slope of the ice duct  373  increases as it goes toward the dispenser  357  from the ice-making unit  361 . Thus, a phenomenon that an object is introduced from outside through one end portion of the ice duct  373  communicating with the dispenser  357  and contacts with the ice separating unit  368  can be prevented. In addition, ice cubes separated by the ice separating unit  368  can be smoothly transferred through the ice duct  373  to the dispenser  357 . 
         [0067]    In the third exemplary embodiment of the present invention as shown in  FIG. 4 , the ice duct  373  extends to slope at two different angles. However, the present invention is not limited thereto, and for example, the ice duct  373  can extend to slop at three or more different angles to have a zigzag shape overall. 
         [0068]    An ice-making device of a refrigerator according to a fourth exemplary embodiment of the present invention will now be described with reference to the accompanying drawings. The construction of an ice-making unit  461  for making and separating or crushing ice cubes and the construction for supplying the ice cubes to a dispenser  457  are the same as those in the first exemplary embodiment of the present invention, so a detailed description therefor will be omitted. 
         [0069]      FIG. 5  is a view illustrating an ice-making device of a refrigerator according to the fourth exemplary embodiment of the present invention. 
         [0070]    With reference to  FIG. 5 , an ice duct  475  extends in a spiral form toward a dispenser  457  from an ice-making unit  461 . Namely, one end portion of the ice duct  475  penetrates one side of a rear surface of a door  455  corresponding to a right lower side of an ice separating unit  468  of the ice-making unit  461  and the other end portion of the ice duct  475  penetrates one side of a front surface of the door  455  corresponding to one side of the upper portion of the dispenser  457 . Accordingly, because the ice duct  475  is formed in the spiral form, the phenomenon that an object is introduced from outside through one end portion of the ice duct  475  and contacts with the ice separating unit  468  can be prevented. 
         [0071]    An ice-making device of a refrigerator according to a fifth exemplary embodiment of the present invention will now be described with reference to the accompanying drawings. The construction of an ice-making unit  561  for making and separating or crushing ice cubes and the construction for supplying the ice cubes to a dispenser  557  are the same as those in the first exemplary embodiment of the present invention, so a detailed description therefor will be omitted. 
         [0072]      FIG. 6  is a view illustrating an ice-making device of a refrigerator according to a fifth exemplary embodiment of the present invention. 
         [0073]    With reference to  FIG. 6 , the ice duct  577  can be controlled in its length, so only when ice cubes are taken out through the dispenser  557 , the ice-making unit  561  and the dispenser  557  are selectively connected by the ice duct  577 . 
         [0074]    In more detail, the ice duct  577  includes first and second ducts  578  and  579 . With one end portion penetrating one side of a rear surface of a door  555  corresponding to a right lower side of an ice separating unit  568  of the ice-making unit  561 , the first duct  578  extends to slope downwardly toward the dispenser  557 . The second duct  579  is installed to be movable in a lengthwise direction of the first duct  578  toward the dispenser  557  in a state of being inserted in the first duct  578 . Accordingly, because one end portion of the second duct  579  selectively penetrates one side of the front surface of the door  555  corresponding to one side of the upper portion of the dispenser  557 , substantially the ice-making unit  561  and the dispenser  557  are selectively connected by the ice duct  577 . 
         [0075]    In the exemplary embodiment as shown in  FIG. 6 , when ice cubes are desired to be taken out through the dispenser  557 , the ice separating unit  568  is operated only when the ice-making unit  561  and the dispenser  557  are connected by the ice duct  577 . For example, a sensor (not shown) can be provided at one side of an upper portion of the dispenser  557  and only when one end portion of the second duct  579  is sensed to have penetrated the one side of the front surface of the door  555  corresponding to one side of the upper portion of the dispenser  557  by the sensor, the ice separating unit  568  can be operated. 
         [0076]    In this manner, only when ice cubes are taken out through the dispenser  557 , the ice-making unit  561  and the dispenser  557  are connected by the ice duct  577 . In addition, the ice separating unit  568  can be operated only when the ice-making unit  561  and the dispenser  557  are connected by the ice duct  557 . Thus, the phenomenon that an object is introduced through the ice duct  577  from outside by a user and damaged by the ice separating unit  568  or the ice separating unit  568  is damaged by the object can be prevented. 
         [0077]    An ice-making device of a refrigerator according to a sixth exemplary embodiment of the present invention will now be described with reference to the accompanying drawings. The construction of an ice-making unit  661  for making and separating or crushing ice cubes and the construction for supplying the ice cubes to a dispenser  657  are the same as those in the first exemplary embodiment of the present invention, so a detailed description therefor will be omitted. 
         [0078]      FIG. 7  is a view illustrating an ice-making device of a refrigerator according to a sixth exemplary embodiment of the present invention. 
         [0079]    With reference to  FIG. 7 , first and second ice ducts  669  and  673  are provided to guide ice cubes or ice pieces separated by an ice separating unit  668 . The first and second ice ducts  669  and  673  are formed as tubes with a certain sectional area. 
         [0080]    The first ice duct  669  is installed such that it penetrates the door  655  slopingly at a certain angle downwardly. One end portion of the first ice duct  669  is positioned at a rear surface of the door  655 , namely, substantially at one side of a mounting end  656 . The other end portion of the first ice duct  669  is positioned at the dispenser  657 . 
         [0081]    The second ice duct  673  is detachably installed on a rear surface of the door  655 . The second ice duct  673  can be integratedly formed with a door basket  671  detachably installed on the rear surface of the door  655 . Thus, as the door basket  671  is detachably attached on the rear surface of the door  655 , the second ice duct  673  is also detachably attached on the rear surface of the door  655 . 
         [0082]    A receptacle space  671   s  for receiving food items is provided within the door basket  671 . The second ice duct  673  is formed to be caved in the receptacle space  671   s  so that one surface of the door basket  671  tightly attached to the rear surface of the door  655  may have a substantially rectangular cross section. Accordingly, the other remaining portions, excluding the second ice duct  673 , of the interior of the door basket  671  substantially become the receptacle space  671   s.    
         [0083]    In a state that the door basket  671  is mounted on the rear surface of the door  655 , its bottom surface is mounted on the upper surface of the mounting end  656 . In a state that the door basket  671  is mounted on the rear surface of the door  655 , one end portion of the second ice duct  673  is positioned at the right lower side of the ice-making unit  651 , and the other end portion of the second ice duct  673  is connected with one end portion of the first ice duct  669  positioned at one side of the mounting end  656 . 
         [0084]    With reference to  FIG. 8 , a partition rib  674  is provided within the second ice duct  673 . The partition rib  674  divides the interior of the second ice duct  673  so that an object can be prevented from contacting with the ice separating unit  668  through the first and second ice ducts  669  and  673 . The partition rib  674  is formed to be long in a direction parallel to a direction in which ice cubes are moved within the second ice duct  673  and divides the interior of the second ice duct  673  into two parts. 
         [0085]    In  FIG. 8 , the interior of the second ice duct  673  is divided into two parts by the partition rib  674 , but the present invention is not limited thereto. For example, the partition rib  674  can be formed long crosswise in a direction parallel to the direction in which the ice cubes are moved within the second ice duct  673 , and in this case, the cross section of each part divided by the partition rib  674  of the second ice duct  673  should be larger than the size of ice cubes separated by the ice separating unit  668 . 
         [0086]    The operation will be described in detail as follows. 
         [0087]    First, when a user manipulates the dispenser  657 , ice cubes stored in the ice bank  664  after being made in an ice maker  663  are transferred to a front end of the ice bank  664  by a screw  665 . The ice cubes transferred to the front end of the ice bank  664  are separated by the ice separating unit  668 . The separated ice cubes by the ice separating unit  668  are transferred to the dispenser  657  through the first and second ice ducts  669  and  673  and then taken out. 
         [0088]    When the user introduces an object from outside to one end portion of the first ice duct  669  positioned at one side of the dispenser  657 , because the first ice duct  669  is connected in a bent form with the second ice duct  673 , the introduction of the object from outside can be prevented. In addition, because the interior of the second ice duct  673  is divided by the partition rib  674 , the phenomenon that the introduced object contacts with the ice separating unit  668  through the first and second ice ducts  669  and  673  and is damaged can be prevented. 
         [0089]    The user can put food items in the receptacle space  671   s  of the door basket  671  except for the second ice duct  673 . Thus, the other remaining space excluding the parts for transferring ice cubes made in the ice-making unit  651  to the dispenser can be effectively used. 
         [0090]    An ice-making device of a refrigerator according to a seventh exemplary embodiment of the present invention will now be described with reference to the accompanying drawings. The construction of an ice-making unit  761  for making and separating or crushing ice cubes and the construction for supplying the ice cubes to a dispenser  757  are the same as those in the first exemplary embodiment of the present invention, so a detailed description therefor will be omitted. 
         [0091]      FIG. 9  is a view illustrating an ice-making device of a refrigerator according to a seventh exemplary embodiment of the present invention, and  FIG. 10  is an enlarged view of an opening and closing member in  FIG. 9 . 
         [0092]    With reference to  FIGS. 9 and 10 , an ice duct  769  includes an opening and closing member  771 . The opening and closing member  771  selectively opens the ice duct  769  only when ice cubes are transferred to the dispenser  757  through the ice duct  769  under the control of a controller. For this purpose, a cross section of the ice duct  769  and the opening and closing member  771  are formed in a rectangular shape and the opening and closing member  771  can be installed such that the other end is rotatable centering on one end. 
         [0093]    The opening and closing member  771  has a shape corresponding to the cross section of the ice duct  769 , and can be installed such that the other end thereof is rotatable in the opposite direction of a direction in which ice cubes are moved within the ice duct  769  centering around one end thereof. 
         [0094]    An opening and closing sensor  773  is provided at one side of the ice duct  769 . The opening and closing sensor  773  senses whether the ice duct  769  is opened or close by the opening and closing member  771  and transfers corresponding information to the controller. In the present exemplary embodiment, the opening and closing sensor  773  is provided at one side within the ice duct  769  adjacent to the opening and closing member  771 , but the present invention is not limited thereto. 
         [0095]    The controller controls the operation of the ice-making unit  761  and opening and closing of the ice duct  769  by the opening and closing member  771 . In more detail, when the controller receives a manipulation signal for extracting ice cubes, it operates the ice-making unit  761 . When the ice-making unit  761  is operated, the controller rotates the opening and closing member  771  to open the ice duct  769 . In this case, the controller substantially controls the opening and closing degree of the ice duct  769  by controlling a rotation angle of the opening and closing member  771  according to a size and an amount of ice cubes separated to certain size after being made in the ice-making unit  761 . Namely, if the size or the amount of separated ice cubes is large, the controller controls the rotation angle of the opening and closing member  771  to be large to relatively increase the opening area of the ice duct  769 . If the size or the amount of the separated ice cubes is small, the controller controls the rotation angle of the opening and closing member  771  to be small to relatively reduce the opening area of the ice duct  769 . 
         [0096]    When the opening and closing member  771  is arbitrarily rotated so the ice duct  769  is opened, the controller stops the operation of the ice-making unit  761 . For example, while ice cubes are made or separated by operating the ice-making unit  761 , when the user put an arbitrary material into the ice duct  769 , the opening and closing member  771  is rotated to open the duct  769 , which is sensed by the opening and closing sensor  773 . Then, upon receiving the corresponding information sensed by the opening and closing sensor  773 , the controller stops operating of the ice-making unit  761 . 
         [0097]    The method of controlling the ice-making device of a refrigerator according to the seventh exemplary embodiment of the present invention will now be described in detail.  FIG. 11  is a flow chart illustrating the processes of a method for controlling an ice-making device of a refrigerator in  FIG. 9 . 
         [0098]    With reference to  FIG. 11 , the controller (C) receives a manipulation signal for extracting ice cubes (S 11 ). Accordingly, the controller (C) operates the ice-making unit  761  to make ice cubes and separate them into a certain size (S 12 ). The controller (C) rotates the opening and closing member  771  to open the ice duct  769  to allow the ice cubes to be taken out through the dispenser  757  (S 13  and S 14 ). In this case, the controller (C) controls the rotation angle of the opening and closing member  771  according to the size of the separated ice cubes and the amount of ice cubes taken out through the dispenser  757  to control an opening degree of the ice duct  769 . Accordingly, because the ice duct  769  is opened as large as to be required for supplying ice cubes, a space allowing an object to be introduced from outside can become smaller, so the introduction of the object can be prevented. In addition, a leakage of cooling air of the interior of a freezing chamber  753  can be minimized. 
         [0099]    The opening and closing degree of the ice duct  769  by the opening and closing member  771 , namely, the rotation angle of the opening and closing member  771 , is sensed by the opening and closing sensor  773  (S 15 ). And the opening and closing sensor  773  transfers information regarding the opening and closing degree of the ice duct  769  to the controller (C) (S 16 ). 
         [0100]    The controller (C) determines whether the ice duct  769  has been normally opened or not by the opening and closing member  771 , namely, whether the opening and closing member  771  has been rotated by a pre-set rotation angle, according to the information received from the opening and closing sensor  773  (S 17 ). When the ice duct  769  has been normally opened by the opening and closing unit  771 , the controller (C) continuously operates the ice-making unit  761  to make and separate ice cubes and supply them to the dispenser  757  through the ice duct  769 . 
         [0101]    If, however, the ice duct  769  has not been normally opened by the opening and closing member  769 , for example, when the user puts an arbitrary object into the ice duct  769  so the opening and closing member  771  has been arbitrarily rotated to open the ice duct  769 , the controller (C) stops the operation of the ice-making unit  761  (S 18 ). Accordingly, a phenomenon that the user&#39;s hand coming into the ice duct  769  and contacts with the ice-making unit  761 , especially, with the ice separating unit  768  so as to hurt can be prevented. 
         [0102]    An ice-making device of a refrigerator according to an eighth exemplary embodiment of the present invention will now be described with reference to the accompanying drawings. The construction of an ice-making unit  861  for making and separating or crushing ice cubes and the construction for supplying the ice cubes to a dispenser  857  are the same as those in the first exemplary embodiment of the present invention, so a detailed description therefor will be omitted. 
         [0103]      FIG. 12  is a view illustrating an ice-making device of a refrigerator according to an eighth exemplary embodiment of the present invention. 
         [0104]    With reference to  FIG. 12 , an internal temperature of an ice duct  869  is sensed, and if the sensed temperature is lower than a certain temperature level, it is determined that a foreign material has been introduced into the ice duct  869  and the operation of the ice-making unit  861  is stopped. For this purpose, a pair of temperature sensors  875  and  877  are provided within the ice duct  869 . 
         [0105]    The temperature sensors  875  and  877  sense the internal temperature of the ice duct  869  and transfer corresponding information to the controller. The temperature sensors  875  and  877  are installed to be spaced apart by a certain interval in a direction parallel to a direction in which ice cubes are moved within the ice duct  869 . In this case, a plurality of temperature sensors can be provided. 
         [0106]    In the following description, it is assumed that two temperature sensors are provided. The first temperature sensor  875  is provided within the ice duct  869  adjacent to a dispenser  857  and the second temperature sensor  877  is provided within the ice duct  869  adjacent to the ice-making unit  861 . 
         [0107]    The controller (C) receives temperature sensed by the first and second temperature sensors  875  and  877 . Only when the temperature sensed by the second temperature sensor  877  is higher than a pre-set temperature level in a state that the temperature sensed by the first temperature sensor  875  is higher than a certain temperature, the controller (C) stops the operation of the ice-making unit  861 . This is because a foreign material coming into the ice duct  869  sequentially bypasses the first and second temperature sensors  875  and  877 , only when the internal temperature of the ice duct  869  is sensed to be higher than the pre-set temperature level, the operation of the ice-making unit  861  is stopped. 
         [0108]    In this case, however, in order to increase the operational stability of the ice-making device of the refrigerator, it can be constructed such that when even one of temperatures sensed by a plurality of temperature sensors is higher than the pre-set temperature level, the operation of the ice-making unit  861  is stopped. 
         [0109]    Or, it is possible that only when temperature sensed by a temperature sensor installed near the ice-making unit  861  is higher than the pre-set temperature level, the operation of the ice-making unit  861  is stopped. 
         [0110]    The method for controlling the ice-making device of the refrigerator according to the eighth exemplary embodiment of the present invention will now be described in detail.  FIG. 13  is a flow chart illustrating the processes of a method for controlling an ice-making device of a refrigerator in  FIG. 12 . 
         [0111]    With reference to  FIG. 13 , when the controller (C) receives a manipulation signal for extracting ice cubes, it operates the ice-making unit  861  to make and separate ice cubes. The ice cubes made and separated in the ice-making unit  861  are supplied to the dispenser  857  through the ice duct  869  (S 21 , S 22  and S 23 ). 
         [0112]    The first and second temperature sensors  875  and  877  sense an internal temperature of the ice duct  869  and transfer corresponding information to the controller (C) (S 25 ). 
         [0113]    The controller (C) determines whether a foreign material has been introduced into the ice duct  869  according to the information received from the first and second temperature sensors  875  and  877 . First, the controller (C) determines whether the internal temperature of the ice duct  869  sensed by the first temperature sensor  875  is higher than a certain temperature (S 26 ). If the internal temperature of the ice duct  869  sensed by the first temperature sensor  875  is normal, namely, is lower than a certain temperature, the controller (C) continuously operates the ice-making unit  861 . If, however, the internal temperature of the ice duct  869  sensed by the first temperature sensor  875  is not normal, namely, is higher than the certain temperature, the controller (C) determines the internal temperature of the ice duct  869  sensed by the second temperature sensor  877 . If the internal temperature of the ice duct  869  sensed by the second temperature sensor  877  is higher than the certain temperature, the controller (C) stops the operation of the ice-making unit  861  (S 28 ). 
         [0114]    For example, when the user puts an arbitrary object into the ice duct  869  so the internal temperature of the ice duct  869  increases, the internal temperature of the ice duct  869  increases abnormally. Thus, in this case, the controller (C) stops the operation of the ice-making unit  861 , so the phenomenon that an object introduced into the ice duct  869  contacts with the ice separating unit of the ice-making unit  861  and hurts can be prevented. 
         [0115]    As so far described, the ice-making device of a refrigerator and its control method according to the present invention have the following advantages. 
         [0116]    That is, because the introduction of an external object into the ice duct through the dispenser of the refrigerator is prevented and the operation of the ice-making unit is stopped, the external object can be prevented from being damaged, so the user can stably use the ice-making device of the refrigerator. 
         [0117]    As the present invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds are therefore intended to be embraced by the appended claims.