Abstract:
In a washing machine according to the present invention, if a washing step is ended, a distribution step that the inner tub containing the washing water is rotated in one direction and fabrics is distributed to a side wall of the inner tub and the washing water is discharged to outside is performed. Because a fabric is evenly distributed in the distribution step, a dehydration step can be performed without carrying out a separate procedure for avoiding unbalance. Therefore, energy such as washing time and power used during the operation of the washing machine and amount of water used can be saved. Also, since a washing machine according to the present invention rotates the inner tub not only during the distribution step but also during the hydration step afterwards, operation of a clutch used to selectively rotate the pulsator and the inner tub at the time of entering to the dehydration step from the distribution step is not required. Therefore, noise due to the operation of a clutch can be reduced and operation time of the washing machine can be reduced.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a washing machine and a control method of the same. More specifically, the present invention relates to a washing machine and a washing method capable of reducing amount of water used and washing time. 
     2. Description of the Conventional Art 
     In general, a washing machine is a device which removes debris of fabric and handles laundry. The washing machine removes debris of fabric in various ways. The washing machine, after removing debris of laundry, performs a step for removing moisture in the laundry. At this time, washing water contained in an inner tub is discharged to the outside. When washing water of the washing machine is discharged to the outside, the washing machine measures the degree of unbalance of the inner tub. If it is found that unbalance of the inner tub exists, the washing machine provides a small amount of washing water to the inner tub. Due to the washing water provided, fabric is made to flow inside the inner tub. At this time, the washing machine again measures the degree of unbalance of the inner tub. The procedure above is repeated until the unbalance of the inner tub is removed. Once unbalance of the inner tub is removed, a driving apparatus removes moisture of fabric by accelerating the inner tub. 
     However, a washing machine according to the related art repeats the above procedure, leading to excessive consumption of washing water and energy. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a washing machine capable of reducing amount of water used and energy. 
     A washing method according to the present invention comprises a washing step that at least one of an inner tub and a pulsator is rotated for washing fabrics; a distribution step that the inner tub containing the washing water is rotated in one direction and fabrics is distributed to a side wall of the inner tub and the washing water is discharged to outside; and a dehydration step that the inner tub is rotated by the dehydration rotation speed for dehydrating fabrics after the distribution step is ended. 
     In the present invention, the washing step comprises a first washing step that the inner tub is rotated in one direction with a first rotation speed so as to form a circulation water flow which is risen between the inner tub and an outer tub by the centrifugal force and then is fed back to the inner tub, and a second washing step that at least one of the inner tub and the pulsator is rotated in both directions alternately with a second rotation speed different from the first rotation speed. 
     In the present invention, the distribution step includes that washing water is discharged by turning on a discharge pump, and the first washing step includes that washing water is not discharged by turning off the discharge pump. 
     In the present invention, the first washing and the second washing are repeated multiple times. 
     In the present invention, the distribution step is performed for a predetermined time and the dehydration step is performed after the predetermined time. 
     In the present invention, the distribution step is completed, unbalance detection step for detecting unbalance of fabrics is performed. 
     In the present invention, if fabric is found unbalanced in the unbalance detection step, the distribution step is performed again. 
     In the present invention, if fabric is found not unbalanced in the unbalance detection step, the dehydration step is performed. 
     In the present invention, further including the balancing step where washing water contained in an inner tub is rotated by rotating at least one of the inner tub and the pulsator. 
     In the present invention, the balancing step is performed between the washing step and the distribution step. 
     In the present invention, when the distribution step is completed, unbalance detection step for detecting unbalance of fabric is performed. 
     In the present invention, if fabric is found unbalanced in the unbalance detection step, the distribution step is performed again. 
     In the present invention, if fabric is found not unbalanced in the unbalance detection step, the dehydration step is performed. 
     A washing machine according to the present invention comprises an inner tub; a pulsator disposed inside the inner tub; a discharge apparatus for discharging washing water of the inner tub outside; a driving apparatus for driving the inner tub and the pulsator; and a controller for controlling the discharge apparatus to discharge washing water and controlling the driving apparatus to rotate the inner tub in one direction. 
     In a washing machine according to the present invention, if a washing step is ended, a distribution step that the inner tub containing the washing water is rotated in one direction and fabrics is distributed to a side wall of the inner tub and the washing water is discharged to outside is performed. Because a fabric is evenly distributed in the distribution step, a dehydration step can be performed without carrying out a separate procedure for avoiding unbalance. Therefore, energy such as washing time and power used during the operation of the washing machine and amount of water used can be saved. Also, since a washing machine according to the present invention rotates the inner tub not only during the distribution step but also during the hydration step afterwards, operation of a clutch used to selectively rotate the pulsator and the inner tub at the time of entering to the dehydration step from the distribution step is not required. Therefore, noise due to the operation of a clutch can be reduced and operation time of the washing machine can be reduced. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       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 serve to explain the principles of the invention. 
       In the drawings: 
         FIG. 1  is a perspective view of one embodiment of a washing machine according to the present invention; 
         FIG. 2  illustrates a cross sectional view of  FIG. 1  as seen along II-II line; 
         FIG. 3  illustrates a block diagram of a control flow of a washing machine of  FIG. 1 ; 
         FIG. 4  illustrates a flow diagram of a washing method of a washing machine according to a first embodiment of the present invention; 
         FIG. 5  illustrates a flow diagram of a washing method of a washing machine according to a second embodiment of the present invention; and 
         FIG. 6  illustrates a flow diagram of a washing method of a washing machine according to a third embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       FIG. 1  is a perspective view of one embodiment of a washing machine according to the present invention and  FIG. 2  illustrates a cross sectional view of  FIG. 1  as seen along II-II line. 
     With reference to  FIGS. 1 and 2 , a washing machine  100  according to the present invention comprises a cabinet  110 ; a outer tub  125  disposed inside the cabinet  110  and storing washing water; an inner tub  122  disposed inside the outer tub  125  and receiving laundry; a driving apparatus  170  rotating the inner tub  122  in both directions alternately or in one direction by delivering driving force to the inner tub  122 ; a discharge apparatus  150  discharging washing water of the outer tub to the outside; and a washing water provision apparatus  120  disposed in one side of the cabinet  110  and providing washing water from the outside to the outer tub  125  and the inner tub  122 . 
     A pulsator  140  is disposed in the bottom surface of the inner tub  122 . The pulsator  140  can be formed as a single body with the inner tub  122 ; and at the same time, the pulsator  140  can be formed separately and combined as such therewith. An operation method varied according to the structure of the inner tub  122  and the pulsator  140  will be described in detail later. 
     The cabinet  110  comprises a cabinet main body  111  having an opening; a base (not shown) disposed in a lower side of the cabinet main body  111  and fastened to the cabinet main body  111 ; a cover (not shown) fastened to the opening; and a control panel  126  formed on one side of the cover and fastened to the cabinet main body  111 . A door  123  capable of rotational movement together with the cover is installed at the cover to open and close the opening. Meanwhile, the control panel  126  incorporates an input unit  116  which receives input signals from a user. 
     The driving apparatus  170  comprises a motor including a rotor and a stator and generating rotational force; a rotation axis delivering rotational force of the motor; and a clutch delivering rotational force of the motor selectively to at least one of the inner tub and the pulsator  140 . 
       FIG. 3  illustrates a block diagram of a control flow of a washing machine  100  of  FIG. 1 . 
     With reference to  FIG. 3 , a washing machine  100  according to the present invention further comprises an input unit  116  disposed on the control panel and receiving input signals entered by the user; and a controller  190  controlling the operation of the washing machine  100  according to the input signals entered to the input unit  116 . 
     The input signal is formed in various ways and determines a washing step or a method for handling laundry. For example, the washing step can include a blue jean step, a bedclothes step, and a wool step. Also, the treatment method of fabric can include a washing method, a dehydration method, and a rinsing method. 
     When the user enters the input signal, the washing machine  100  performs a washing step. In the washing step, the controller  190  makes washing water flow into the inner tub  122  by operating the washing water provision apparatus  120 . 
     When the washing water provision apparatus  120  begins to operate, washing water is provided to the inner tub  122  from the outside. 
       FIG. 4  illustrates a flow diagram of a washing method of a washing machine according to a first embodiment of the present invention. 
     With reference to  FIG. 4 , when provision of the washing water is completed, the controller  190  performs a washing step, removing dirt of fabric while controlling the operation of the driving apparatus  170 . 
     According to a control method of the driving apparatus  170 , the washing step can be classified as described below. The washing step can include a first washing step S 120  forming a circulating water flow fed back to the inner tub after washing water has risen in between the inner tub  122  and the outer tub  125  due to centrifugal force developed as the inner tub  122  is rotated in one direction with a first rotation speed; and a second washing step S 130  rotating at least one of the inner tub  122  and the pulsator  140  in both directions alternately with a second rotation speed different from the first rotation speed. 
     In the first washing step S 120 , the driving apparatus  170  rotates the inner tub  122  in one direction with the first rotation speed. By centrifugal force generated by accelerated rotation of the inner tub  122  in one direction, a part of fabric put inside the inner tub  122  can be distributed being adhered closely to the inner wall of the inner tub  122  together with washing water. At this time, washing water can make an inclination with a predetermined angle with respect to the inner wall of the inner tub  122 . In other words, the washing water can be so formed that width from the inner wall of the inner tub  122  is thicker in a lower part than that in an upper part. 
     Also, the washing water flows out to the outer tub  125  through a plurality of holes formed in the inner tub  122 . If the inner tub  122  continues to rotate, washing water moves from a space between the inner tub  122  and the outer tub  125  to the upper side. Washing water which has moved to the upper side of the outer tub  125  runs into the tub cover disposed in the upper side of the outer tub  125  and then drops into the inside of the inner tub  122 . Washing water dropping into the inside of the inner tub  122  runs into laundry; fabric is washed being forced from dropping washing water. At this time, the first rotation speed can be set to exceed a second rotation speed described later S 120 . 
     Meanwhile, in the second washing step S 130 , the driving apparatus  170  can rotate at least one of the pulsator  140  and the inner tub  122  in both directions alternately with a second rotation speed different from the first rotation speed. 
     At this time, when the pulsator  140  and the inner tub  122  are combined together being formed separately, the controller  190 , by controlling the operation of the clutch (not shown), can rotate selectively at least one of the pulsator  140  and the inner tub  122  in a predetermined direction. The driving apparatus  170  can rotate the pulsator  140  and the inner tub  122  in different directions from each other. At least one of the pulsator  140  and the inner tub  122  can be rotated in clockwise direction and then in counter clockwise direction after a predetermined time. Also, the driving apparatus  170  can rotate the other one from the pulsator  140  and the inner tub  122  in counter clockwise direction and then again in clockwise direction after a predetermined time. In case the pulsator  140  rotates, washing water inside the inner tub  122  can form a water flow due to the pulsator  140 . Due to the water flow, washing water flows and produces friction against laundry; and fabric can be washed owing to the friction. 
     Meanwhile, in case the pulsator  140  and the inner tub  122  are formed as a single body, the controller  190 , while rotating the inner tub  122  with the second rotation speed, can control the driving apparatus  170  to rotate in both directions alternately. When the inner tub  122  rotates, the pulsator  140  can rotate in the same direction as the inner tub  122 . During the rotation of the inner tub  122 , washing water does not move to the upper side of the outer tub  125 . When the inner tub  122  repeats rotation in both directions, washing water can form a water flow inside the inner tub  122 . Washing water inside the outer tub  125  rotates according to the rotation direction of the inner tub  122 . Fabric can be washed as washing water and fabric are rotated in the same direction as that of the inner tub  122 , S 130 . 
     At the time, the first washing step S 120  and the second washing S 130  are performed alternately, performing order thereof being allowed to be changed. 
     Meanwhile, after a predetermined time, the controller  190  measures a number N of performance of the first washing step S 120  and the second washing step S 130 . S 140   
     When the number N is less than a predetermined number n, the controller  190  adds one to the number N of performance of the washing steps S 141 . 
     Then, the controller  190  repeats performing the first washing step S 120  and the second washing step S 130  sequentially. 
     If the number N of performance of the washing steps is determined to be more than the predetermined number n, the controller  190  terminates the steps. In other words, the controller  190  terminates the washing step. 
     When the washing step is terminated, the controller  190  performs a distribution step S 150 . In the distribution step S 150 , the controller  190  rotates the inner tub  122  in one direction by controlling the driving apparatus  170  while washing water is contained in the inner tub  122 . Fabric inside the inner tub  122  can be distributed across a side wall of the inner tub  122  by centrifugal force developed by rotation of the inner tub  122  in one direction. Also, the controller  190  operates a discharge pump of a discharge apparatus  150  to discharge washing water of the inner tub  122  to the outside. At this time, the controller  190  can operate the discharge pump not only after the inner tub  122  has been rotated in one direction for a predetermined time but also while the inner tub  122  is being rotated in one direction. 
     As fabrics distributed across a side wall of the inner tub  122  and washing water is discharged to the outside by the operation of the discharge apparatus  150 , unbalance of the inner tub  122  can be minimized. Also, moisture of fabric can be removed quickly. Moreover, since washing water is not provided to compensate unbalance of the inner tub  122 , amount of water used can be reduced. S 150   
     When the distribution step S 150  is terminated, the controller  190 , by accelerated rotation of the inner tub  122  with a dehydration speed, performs dehydration step to remove moisture of fabric S 160 . 
     At this time, since the inner tub  122  has been made to rotate in the distribution step S 150  before the dehydration step S 160 , accelerated rotation of the inner tub  122  can be possible without a operation of the clutch in the dehydration step S 160 . Therefore, noise due to the operation of the clutch, operation time, and energy can be reduced. 
     Since additional washing water is not provided to accommodate unbalance of the inner tub  122  before entering into the dehydration step S 160 , not only amount of water used can be reduced but also amount of washing water to be drained during the dehydration step S 160  is reduced; therefore, an advantageous effect can be obtained that dehydration time can be reduced. 
       FIG. 5  illustrates a flow diagram of a washing method of a washing machine according to a second embodiment of the present invention. 
     With reference to  FIG. 5 , a washing method of a washing machine according to a second embodiment of the present invention is described. 
     First, after washing water is supplied, the controller  190  performs washing which removes dirt of fabric while controlling the operation of the driving apparatus  170 . 
     The washing includes a first washing S 220  which rotates the inner tub  122  in one direction and a second washing S 230  which rotates at least one of the inner tub  122  and the pulsator  140  in both directions alternately. Since detailed description thereof is the same as in the first embodiment, description associated therewith is not provided further. 
     Meanwhile, after a predetermined time is passed, the controller  190  measures a number N of performance of the first washing step S 220  and the second washing step S 230 . S 240 . 
     When the number N is less than a predetermined number n, the controller  190  adds one to the number N of performance of the washing step S 241 . 
     Then, the controller  190  repeats performing the first washing step S 220  and the second washing step S 230  sequentially. 
     If the number N of performance of the washing step is determined to be more than the predetermined number n, the controller  190  terminates the steps. In other words, the controller  190  terminates the washing step. 
     After the washing is completed, the controller  190  performs a balancing step S 250  to form a rotating water flow of washing water. At this time, washing water is rotated by rotating at least one of the inner tub  122  and the pulsator  140  selectively. In the balancing step S 250 , employed is rotation speed slower than that in the washing or distribution step S 260  described later. 
     After performance of the balancing step S 250  for a predetermined time, distribution step S 260  is performed. Both the distribution step S 260  and the balancing step S 250  aim to remove unbalance by distributing laundry; the two steps are different by rotation speed, washing water flow, and discharge state. 
     In other words, the distribution step S 260  makes fabric adhere closely to a side wall of the inner tub  122  by centrifugal force developed by rotation of the inner tub  122  with higher speed than in the balancing step S 250 . At this time, the controller rotates the inner tub  122  while washing water is contained in the inner tub  122 . And since a discharge pump of the discharge apparatus  150  is turned on in the distribution step, washing water of the inner tub  122  is discharged to the outer tub  125  through the holes of the discharge apparatus  150 , helping fabric adhere to the inner wall of the inner tub  122 . As fabric is distributed across a side wall of the inner tub  122  and washing water is discharged to the outside by the operation of the discharge apparatus  150 , unbalance of the inner tub  122  can be minimized. Also, moisture of fabric can be removed quickly. Moreover, since washing water is not provided to compensate unbalance of the inner tub  122 , amount of water used can be reduced. 
     When the distribution step S 260  is completed, the controller  190  determines the degree of unbalance of the inner tub  122 , S 270 . 
     If it is found that unbalance of the inner tub exists, the controller  190  performs the distribution step S 260  again. At this time, even if unbalance is detected, the controller  190  does not provide additional water supply. 
     If it is determined that unbalance of the inner tub  122  does not exist, the controller  190  performs dehydration step S 280  which removes moisture of fabric by accelerated rotation of the inner tub  122  with a dehydration speed. 
     At this time, because the inner tub  122  is rotated in the distribution step S 260  before the dehydration step S 280 , accelerated rotation of the inner tub  122  can be possible without the operation of the clutch in the dehydration step S 280 . Therefore, noise due to the operation of the clutch, operation time, and energy can be reduced. 
     Since additional washing water is not provided to accommodate unbalance of the inner tub  122  before entering into the dehydration step S 160 , not only amount of water used can be reduced but also amount of washing water to be drained during the dehydration step S 160  is reduced; therefore, an advantageous effect can be obtained that dehydration time can be reduced. 
     A washing method of a washing machine according to a second embodiment of the present invention can minimize unbalance of the inner tub  122  by repeating the distribution step S 260  according to the existence of unbalance of the inner tub  122 , thereby improving the user satisfaction owing to the improvement of quietness at the time of spin drying. 
       FIG. 6  illustrates a flow diagram of a washing method of a washing machine according to a third embodiment of the present invention. 
     With reference to  FIG. 6 , a washing method of a washing machine according to a third embodiment of the present invention is described. 
     First, after washing water is supplied, the controller  190  performs washing which removes dirt of fabric while controlling the operation of the driving apparatus  170 . 
     The washing includes a first washing step S 320  which rotates the inner tub  122  in one direction and a second washing step S 330  which rotates at least one of the inner tub  122  and the pulsator  140  in both directions alternately. Since detailed description thereof is the same as in the first embodiment, description associated therewith is not provided further. 
     Meanwhile, after a predetermined time is passed, the controller  190  measures a number N of performance of the first washing step S 320  and the second washing step S 330 . S 340 . 
     When the number N is less than a predetermined number n, the controller  190  adds one to the number N of performance of the washing steps S 341 . 
     Then, the controller  190  repeats performing the first washing step S 320  and the second washing step S 330  sequentially. 
     If the number N of performance of the washing step is determined to be more than the predetermined number n, the controller  190  terminates the steps. In other words, the controller  190  terminates the washing step. 
     After the washing is completed, the controller  190  performs balancing step S 350  to form a rotating water flow of washing water. Since the balancing step S 350  is the same as in the second embodiment, description associated therewith is not provided further. 
     After performance of the balancing step S 350  for a predetermined time, distribution step S 360  is performed. 
     The distribution step S 360  makes fabric adhere closely to a side wall of the inner tub  122  by centrifugal force developed by rotation of the inner tub  122  with higher speed than in the balancing step S 350 . Also, since a discharge pump of the discharge apparatus  150  is turned on in the distribution step, washing water of the inner tub  122  is discharged to the outer tub  125  through the holes of the discharge apparatus  150 , helping fabric adhere to the inner wall of the inner tub  122 . As fabric is distributed across a side wall of the inner tub  122  and washing water is discharged to the outside by the operation of the discharge apparatus  150 , unbalance of the inner tub  122  can be minimized. Also, moisture of fabric can be removed quickly. Moreover, since washing water is not provided to compensate unbalance of the inner tub  122 , amount of water used can be reduced. 
     When the distribution step S 360  is completed, the controller  190  performs dehydration step S 370  which removes moisture of fabric by accelerated rotation of the inner tub  122  with a dehydration step speed. 
     A washing method of a washing machine according to a third embodiment of the present invention, when the distribution step S 360  is completed, does not determine the existence of unbalance and not readily enter into the dehydration step S 370 ; therefore, operation time of a washing machine can be reduced. 
     It will be apparent to those skilled in the art that other specific embodiments of the invention can be made without departing from the spirit or modifying fundamental characteristics of the invention. Thus, it should be understood that the embodiments described above are provided as examples in all aspects and do not limit modifications and variations of the invention. The scope of the invention is specified by the appended claims rather than the detailed description given above. It should be interpreted that the spirit and the scope of the claims and all the modifications or variations derived from their equivalents belong to the scope of the invention.