Patent Abstract:
A washing machine and method of controlling the washing machine. The washing machine includes a fixed tub, a rotating tub, a detergent dispenser and a control unit. The detergent dispenser contains a detergent, receives a preset quantity of washing water and allows the detergent to be dissolved therein, thus forming a liquid detergent. The control unit controls the liquid detergent contained in the detergent dispenser to be sprayed on laundry in the rotating tub after a completion of direct supplying of a large amount of the washing water to one or more of the fixed tub and the rotating tub.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATION  
         [0001]    This application claims the benefit of Korean Application No. 2002-41967, filed Jul. 18, 2002, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention relates generally to a washing machine and method of controlling the same, and more particularly, to a washing machine and method of controlling the same, which dissolves a detergent using a detergent dispenser and supplies the dissolved liquid detergent to a washing tub.  
           [0004]    2. Description of the Related Art  
           [0005]    In general, washing machines are divided into drum-type washing machines and washing machines using pulsators. The drum-type washing machine washes laundry by a displacement of the laundry caused by a rotation of a rotating tub, while the washing machine using the pulsator washes the laundry by water currents generated by a rotation of the pulsator mounted on a bottom surface of a tub. Since the drum-type washing machine washes the laundry by the displacement caused by the rotation of the rotating tub, a small quantity of washing water to soak the laundry is used. This is one of advantages of the drum-type washing machine. Since the washing machine using the pulsator has to generate strong water currents by rotating the pulsator after supplying sufficient washing water for the laundry to be completely submerged under the washing water, a large quantity of washing water is needed in comparison with the drum-type washing machine.  
           [0006]    [0006]FIG. 1 is a perspective view illustrating a construction of a conventional drum-type washing machine. As shown in FIG. 1, a fixed tub  102  is mounted in a body  100  to contain washing water therein, and a rotating tub  108  is mounted in the fixed tub  102  to perform washing, rinsing and spin-drying processes by a rotation of a motor  110 . A number of holes are formed in a surface of the rotating tub  108 , so the washing water can flow from the rotating tub  108  to the fixed tub  102  and vice versa through the holes and washing the water centrifugally separated from the laundry flows into a space between the rotating tub  108  and the fixed tub  102  during the spin-drying process. A washing machine provided with a drying heater  114  drying the laundry can further perform a drying process in addition to the washing, rinsing, and spin-drying processes of a general drum-type washing machine. In FIG. 1, hot and cold washing water passed through water supply valves  118  and  120  are first supplied by water pipes  124  to a detergent dispenser  122  and then supplied to the fixed tub  102  through a water supply pipe  126  along with a detergent.  
           [0007]    [0007]FIG. 2 is a flowchart showing a method of controlling the conventional drum-type washing machine. As shown in FIG. 2, a washing course is set by a user at operation S 202 , and washing water of a quantity corresponding to the set washing course is supplied to the fixed tub  102  through the detergent dispenser  122  at operation S 204 . A detergent contained in the detergent dispenser  122  is dissolved by the washing water and supplied to the fixed tub  102  along with the washing water. After the washing water of the quantity corresponding to the set washing course has been supplied, a washing process is performed by the rotation of the rotating tub  108  at operation S 206 . After the washing process has been completed, a rinsing process is performed by repeating the supplying of a preset quantity of the washing water and spin-drying at operation S 208 . After the rinsing process has been completed, a spin-drying process is performed by the rotation of the rotating tub  108  at operation S 210 . After the spin-drying process has been completed, a drying process that removes the washing water soaked in the laundry in the rotating tub  108  is performed by operating the drying heater  114  at operation S 212 .  
           [0008]    In the conventional drum-type washing machine, the washing water supplied to the detergent dispenser  122  is supplied to the fixed tub  102  through the detergent dispenser  122 . In a course of supplying the washing water, the detergent contained in the detergent dispenser  122  is dissolved and supplied to the fixed tub  102  along with the washing water. In this case, since the washing water passes through the detergent dispenser  122  at a high speed, the detergent is supplied to the fixed tub  102  along with the washing water with the detergent insufficiently dissolved. The detergent needs to be sufficiently dissolved to prevent stains generated by an undissolved detergent from remaining on the laundry, and to improve a washing efficiency. Accordingly, after the supplying of the washing water and the detergent is completed, the detergent needs to be sufficiently diluted with the washing water by a forward rotation and a reverse rotation of the rotating tub  108  in the drum-type washing machine.  
           [0009]    To sufficiently dilute the undissolved detergent in the rotating tub  108  with the washing water, a larger quantity of the washing water than a normal quantity of the washing water is needed. Although the drum-type washing machine is designed to wash the laundry with a small quantity of the washing water to soak the laundry, the larger quantity of the washing water than the normal quantity of the washing water has to be supplied to sufficiently dissolve the detergent because of the detergent sinking to a bottom of the fixed tub  102  which has to be dissolved using water currents generated by the forward rotation and the reverse rotation of the rotating tub  108 . Thus, the quantity of the washing water is unavoidably increased to be equal to or greater than a maximum quantity of the washing water to soak the laundry in the conventional drum-type washing machine, so an increase in the quantity of the washing water causes an excessive consumption of the washing water, an increase in an amount of load on a rotating tub driving motor, and increases a time and energy required to heat the washing water in the drum-type washing machine in which a boiling process is carried out, thus increasing a power consumption and a total operating time thereof.  
         SUMMARY OF THE INVENTION  
         [0010]    Accordingly, an aspect of the present invention is to provide a washing machine and method of controlling the washing machine, in which a large quantity of washing water is directly supplied to a rotating tub, a small quantity of the washing water to dissolve detergent is supplied to a detergent dispenser separately from the directly supplied washing water to allow the detergent to be dissolved at a high concentration in the detergent dispenser, and the dissolved high concentration liquid detergent is supplied to the rotating tub after the directly supplied washing water has been supplied to the rotating tub so that the laundry is sufficiently soaked in the washing water.  
           [0011]    Additional aspects and advantages of the invention 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 invention.  
           [0012]    To accomplish the above and/or other aspects, a washing machine having a fixed tub and a rotating tub, comprising a detergent dispenser containing a detergent, receiving a preset quantity of washing water and allowing the detergent to be dissolved therein, thus forming a liquid detergent; and a control unit controlling the liquid detergent contained in the detergent dispenser to be sprayed on laundry in the rotating tub after a completion of direct supplying of a large amount of the washing water to the fixed tub. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    These and other aspects and advantages of the invention will become apparent and more readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings of which:  
         [0014]    [0014]FIG. 1 is a perspective view illustrating a construction of a conventional drum-type washing machine;  
         [0015]    [0015]FIG. 2 is a flowchart illustrating a conventional method of controlling the conventional drum-type washing machine;  
         [0016]    [0016]FIG. 3 is a perspective view illustrating a construction of a drum-type washing machine in accordance with an embodiment of the present invention;  
         [0017]    [0017]FIG. 4 is a block diagram illustrating the drum-type washing machine of FIG. 3; and  
         [0018]    [0018]FIG. 5 is a flowchart illustrating a method of controlling the drum-type washing machine of FIG. 3. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0019]    Reference will now made in detail to the present preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures.  
         [0020]    Referring to FIGS.  3  to  5 , a washing machine and control method thereof is described. FIG. 3 is a perspective view illustrating a construction of a drum-type washing machine in accordance with an embodiment of the present invention. As shown in FIG. 3, a fixed tub  302  is mounted in a body  300  to contain washing water, and a rotating tub  308  is mounted in the fixed tub  302  to perform washing, rinsing, and spin-drying processes while being rotated by a driving force of a motor  310 . A number of holes are formed in the rotating tub  308 , so that the washing water can flow from the rotating tub  308  to the fixed tub  302  and vice versa and the washing water centrifugally separated from laundry flows into a space between the rotating tub  308  and the fixed tub  302  during a spin-drying process. The washing machine may be provided with a drying heater  314  drying the laundry. The drying heater performs a drying process in addition to the washing, rinsing, and spin-drying processes of a drum-type washing machine. Further, the drum-type washing machine provided with a washing water heating unit  330  can provide a same effect as that of directly boiling the laundry by heating the washing water to a high temperature. A large part of the washing water supplied through a first water supply valve  318  and a second water supply valve  320  is directly supplied to the fixed tub  302  through water supply pipes  328 . A remaining small part of the washing water supplied through the first and second water supply valves  318  and  320  is supplied to a detergent dispenser  322  through the water supply pipes  324  and used to dissolve the detergent contained in the detergent dispenser  322 . The liquid detergent dissolved by the remaining small part of the washing water in the detergent dispenser is supplied to the fixed tub  302  by a water pipe  328  that is connected between the detergent dispenser  322  and the fixed tub  302  after a completion of the direct supplying of the large part of the washing water.  
         [0021]    In the washing machine, the small part of the washing water containing the detergent is sprayed on the laundry in the rotating tub  308 , so that the large part of the washing water is uniformly supplied to the laundry, as a whole. After the direct supplying of the large part of the washing water is completed, the liquid detergent, which is supplied from the detergent dispenser  322  to the fixed tub  302 , is sprayed on the laundry, so that the liquid detergent is uniformly supplied to the whole laundry.  
         [0022]    In the washing machine a sum of a quantity of the washing water directly supplied to the fixed tub  302  and a quantity of the washing water supplied to the detergent dispenser  322  is less than or equal to a quantity of the washing water corresponding to a washing course set by a user. For example, when the quantity of the washing water corresponding to the set washing course is 10 liters, the sum of the quantity of the washing water supplied to the fixed tub  302  and the quantity of the washing water supplied to the detergent dispenser  322  is less than or equal to 10 liters. This restriction prevents a total quantity of the washing water from increasing as a result of an addition of the quantity of the washing water to dissolve the detergent to the quantity of washing water corresponding to the set washing course. Accordingly, an increase in the total quantity of the washing water is suppressible.  
         [0023]    [0023]FIG. 3 shows the construction of a drum-type washing machine of an embodiment of the present invention. However, it is understood by those of skill in the art that the above-described construction can be applied to general washing machines using pulsators.  
         [0024]    [0024]FIG. 4 is a block diagram illustrating the drum-type washing machine FIG. 3. As shown in FIG. 4, a control unit  402  controls an overall operation of the washing machine, such as washing, rinsing, spin-drying, and drying processes. An input unit  406  sets washing conditions desired by a user, or selectively commands only processes needed by a user. The washing conditions and commands set by the input unit  406  are transmitted to the control unit  402 . A water level sensor  404  is used to detect a quantity of washing water supplied, and detects the quantity of the washing water supplied to the fixed tub  302  and provides information about the detected quantity of the washing water to the control unit  402 .  
         [0025]    A drive unit  410  drives the motor  310 , a drain pump  316 , the drying heater  314 , a display unit  412 , the first and second water supply valves  318  and  320  and the like. The motor  310  periodically rotates the rotating tub  308  in forward and reverse directions at a high speed during washing or rinsing processes, and rotates the rotating tub  308  in a forward direction at the high speed during a spin-drying process. The drain pump  316  discharges the washing water stagnating on a bottom surface of the fixed tub  302 . The drying heater  314  dries the laundry by circulating heated air through the fixed tub  302 . The display unit  412  visually displays an operating state of the drum-type washing machine. The first and second water supply valves  318  and  320  control the supplying of hot and cold water, respectively.  
         [0026]    Referring to FIG. 5, a method of controlling the drum-type washing machine FIG. 3 is described. FIG. 5 is a flowchart illustrating the drum-type washing machine control method. As shown in FIG. 5, if a washing course is set by a user at operation S 502 , a preset small quantity of the washing water is supplied to the detergent dispenser  322  through the first and second water supply valves  318  and  320 , and the detergent contained in the detergent dispenser  322  is dissolved at operation S 504   a.  Simultaneously, the washing water of a quantity obtained by subtracting the preset small quantity of the washing water supplied to the detergent dispenser  322  from a total quantity of the washing water corresponding to the washing course set by the user is directly supplied to the fixed tub  302  through the water supply pipes  328  and sprayed on the laundry at operation S 504   b.  Accordingly, the laundry can be uniformly soaked by spraying a large part of washing water thereon.  
         [0027]    After the supplying of the large part of the washing water to the fixed tub  302  is completed, a high concentration liquid detergent dissolved by the washing water in the detergent dispenser  322  is sprayed on the sufficiently soaked laundry on which the large part of the washing water has been sprayed at operation S 506 . Since the sufficiently dissolved liquid detergent is sprayed on the laundry after the large part of the washing water has been supplied to the laundry and then the laundry has been sufficiently soaked, a generation of stains on the laundry, which may be generated by the detergent when an insufficiently dissolved detergent is supplied to the laundry that is insufficiently soaked, is preventable. Further, since the detergent can be dissolved by the small quantity of the washing water, the total quantity of the washing water is decreased in comparison with a case where the total quantity of the washing water and the detergent have been supplied together and then the detergent is dissolved in the fixed tub  302 . Therefore, a quantity of used washing water can be decreased. Further, since the previously dissolved detergent is supplied to the fixed tub  302 , the undissolved detergent does not remain, so the washing performance of the washing machine is maximized.  
         [0028]    After the supplying of the washing water and the liquid detergent is completed, the washing process is performed by rotating the rotating tub  308  at operation S 508 . Thereafter, the rinsing process is performed by repeating the supplying of the washing water and spin-drying at operation S 510 . Thereafter, the spin-drying process is performed by rotating the rotating tub  308  at operation S 512 . After the spin-drying process is completed, the drying process that removes the water soaked in the laundry in the rotating tub  308  is performed by operating the drying heater  314  at operation S 514 .  
         [0029]    The drum-type washing machine is constructed so that a large part of washing water is directly supplied to the fixed and rotating tubs without passing through a detergent dispenser, and a small part of the washing water to dissolve a detergent is supplied to the detergent dispenser separately from the large part of the washing water to dissolve the detergent at a high concentration in the detergent dispenser. With this construction, stains, which may be generated by an undissolved detergent remaining on laundry, are preventable and a washing performance of the drum-type washing machine can be improved by sufficiently spraying the high concentration liquid detergent on the laundry after the large part of the washing water is supplied to the fixed tub. Further, since the previously dissolved detergent is supplied, a total quantity of the washing water can be greatly decreased in comparison with a case where the washing water and the detergent are supplied together, and a power consumption and a total time required to wash the laundry are decreased by a reduction in an amount of load on the rotating tub driving motor. Further, since the total quantity of the washing water is decreased, a time required to heat the washing water is greatly decreased in washing machines that perform a boiling process by heating the washing water.  
         [0030]    Although a few preferred embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the claims and their equivalents.

Technology Classification (CPC): 3