Washing machine and control method thereof

Abstract

A washing machine for reducing vibration and noise during a spin-drying cycle, and a control method thereof. According to the washing machine and the control method thereof, cloth piled up randomly in the washing tub is shaken and loosened through the stirring from side to side of the pulsator or the washing tub before water is supplied after putting the cloth therein, so that distribution of the cloth is made uniform to reduce vibration and noise during the spin-drying cycle. Further, unsatisfactory spin-drying due to abnormal vibration is prevented so that it is possible to reduce unnecessary consumption of water and spin-drying time. Further, even when the user does not put detergent in the detergent box but puts it directly onto the cloth, the detergent is shaken by the movement of the cloth, so it is possible to improve washing performance as the detergent and water are mixed well.

What is claimed is: 
     
         1 . A method of controlling a washing machine including a washing tub accommodating cloth and a pulsator rotatably installed in the washing tub, the method comprising:
 (a) rotating the pulsator in one direction for a first time before supplying water to the washing tub;   (b) stopping the pulsator for a second time after the pulsator rotates in one direction;   (c) rotating the pulsator in an opposite direction for a third time when the second time elapses; and   (d) stopping the pulsator for a fourth time after the pulsator rotates in the opposite direction,   wherein a balance cycle is carried out by performing a stirring operation of the pulsator configured of operations (a) to (d) from side to side at least once or more so as to uniformly distribute the cloth.   
     
     
         2 . The method according to  claim 1 , wherein the balance cycle is carried out before a water supply cycle of first supplying water for washing the cloth. 
     
     
         3 . The method according to  claim 1 , wherein the pulsator is rotated by a motor, and
 wherein the pulsator is driven in a forward direction for the first time while maintaining the motor at a predetermined RPM during the rotation of the pulsator in one direction.   
     
     
         4 . The method according to  claim 3 , wherein the pulsator is driven in a backward direction for the third time while maintaining the motor at a predetermined RPM during the rotation of the pulsator in an opposite direction. 
     
     
         5 . The method according to  claim 4 , wherein the first time is set to be equal to the third time. 
     
     
         6 . The method according to  claim 5 , wherein the second time is set to be equal to the fourth time. 
     
     
         7 . The method according to  claim 6 , wherein the second time is set to be shorter than the first time. 
     
     
         8 . The method according to  claim 7 , wherein the first time is set to be 1.4 seconds. 
     
     
         9 . The method according to  claim 7 , wherein the second time is set to be 0.9 seconds. 
     
     
         10 . The method according to  claim 4 , wherein the first time is set to be different from the third time. 
     
     
         11 . The method according to  claim 4 , wherein the second time is set to be different from the fourth time. 
     
     
         12 . The method according to  claim 4 , wherein the predetermined RPM is at least 500 RPM or more at the time of stirring the pulsator from side to side. 
     
     
         13 . The method according to  claim 4 , further comprising changing the motor RPM at the time of stirring the pulsator from side to side. 
     
     
         14 . The method according to  claim 1 , further comprising changing a motor driving time or a motor stopping time at the time of stirring the pulsator from side to side. 
     
     
         15 . The method according to  claim 4 , further comprising:
 detecting a weight of the cloth; and   changing the motor RPM according to the detected weight of the cloth.   
     
     
         16 . The method according to  claim 4 , further comprising:
 detecting a weight of the cloth; and   changing the motor driving time or the motor stopping time according to the detected weight of the cloth.   
     
     
         17 . The method according to  claim 1 , wherein the balance cycle is carried out before a spin-drying cycle of the washing machine. 
     
     
         18 . The method according to  claim 1 , further comprising:
 counting the number of operating times of stirring the pulsator from side to side;   comparing the counted number of times of stirring with a defined reference number of times of stirring; and   stopping the stirring operation of the pulsator from side to side when the number of times of stirring is the reference number of times of stirring or more.   
     
     
         19 . The method according to  claim 18 , wherein the reference number of times of stirring is at least one or more. 
     
     
         20 . A method of controlling a washing machine including a washing tub accommodating cloth and a motor rotating the washing tub, the method comprising:
 (A) rotating the washing tub in one direction for a fifth time before supplying water to the washing tub;   (B) stopping the washing tub for a sixth time after the washing tub rotates in one direction;   (C) rotating the washing tub in an opposite direction for a seventh time when the sixth time elapses; and   (D) stopping the washing tub for an eighth time after the washing tub rotates in the opposite direction,   wherein a balance cycle is carried out by performing a stirring operation of the washing tub configured of operations (A) to (D) from side to side at least once or more so as to uniformly distribute the cloth.   
     
     
         21 . The method according to  claim 20 , wherein the fifth time is set to be equal to the seventh time. 
     
     
         22 . The method according to  claim 21 , wherein the sixth time is set to be equal to the eighth time. 
     
     
         23 . The method according to  claim 22 , wherein the fifth time is set to be shorter than the sixth time. 
     
     
         24 . The method according to  claim 23 , wherein the fifth time is set to be 1.9 seconds. 
     
     
         25 . The method according to  claim 23 , wherein the sixth time is set to be 2 seconds. 
     
     
         26 . The method according to  claim 20 , wherein the fifth time is set to be different from the seventh time. 
     
     
         27 . The method according to  claim 20 , wherein the sixth time is set to be different from the eighth time. 
     
     
         28 . The method according to  claim 20 , wherein the motor RPM is at least 150 RPM or more at the time of stirring the washing tub from side to side. 
     
     
         29 . A washing machine, comprising:
 a washing tub configured to accommodate cloth;   a pulsator rotatably installed in the washing tub;   a motor configured to rotate the pulsator; and   a controller configured to carry out a balance cycle controlling the motor before supplying water to the washing tub to stir the pulsator from side to side, and count the number of times of stirring of the pulsator to stop the stirring operation of the pulsator from side to side when the counted number reaches a defined reference number of times of stirring.   
     
     
         30 . The washing machine according to  claim 29 , wherein the controller drives the motor at a predetermined RPM and an operating rate at the time of stirring the pulsator from side to side. 
     
     
         31 . The washing machine according to  claim 30 , wherein the controller maintains the motor RPM at least at 500 RPM or more to stir and rotate the pulsator. 
     
     
         32 . The washing machine according to  claim 31 , wherein the controller sets off time of the operating rate of the motor to be shorter than on time thereof at the time of stirring and rotating the pulsator so as to introduce an air layer between the cloths. 
     
     
         33 . The washing machine according to  claim 30 , wherein the controller detects a weight of the cloth and controls the motor RPM according to the detected weight of the cloth. 
     
     
         34 . The washing machine according to  claim 30 , wherein the controller detects a weight of the cloth and changes the operating rate of the motor according to the detected weight of the cloth. 
     
     
         35 . A washing machine, comprising:
 a washing tub configured to accommodate cloth;   a motor configured to rotate the washing tub; and   a controller configured to carry out a balance cycle controlling the motor before supplying water to the washing tub to stir the washing tub from side to side, and count the number of times of stirring of the washing tub to stop the stirring operation of the washing tub from side to side when the counted number reaches a defined reference number of times of stirring.   
     
     
         36 . The washing machine according to  claim 35 , wherein the controller drives the motor at a predetermined RPM and an operating rate at the time of stirring the washing tub from side to side. 
     
     
         37 . The washing machine according to  claim 36 , wherein the controller maintains the motor RPM at least at 150 RPM or more to stir and rotate the washing tub. 
     
     
         38 . The washing machine according to  claim 37 , wherein the controller sets on time of the operating rate of the motor to be shorter than off time thereof at the time of stirring and rotating the washing tub so as to introduce an air layer between the cloths. 
     
     
         39 . The washing machine according to  claim 36 , wherein the controller detects a weight of the cloth and controls the motor RPM according to the detected weight of the cloth. 
     
     
         40 . The washing machine according to  claim 36 , wherein the controller detects a weight of the cloth and changes the operating rate of the motor according to the detected weight of the cloth. 
     
     
         41 . A method of controlling a washing machine including a washing tub accommodating cloth and a pulsator rotatably installed in the washing tub, the method comprising:
 supplying water to the washing tub for washing; and   rotating the pulsator to perform washing after supplying water,   wherein a balance cycle is carried out by stirring the pulsator from side to side so as to uniformly distribute the cloth before supplying water to the washing tub.   
     
     
         42 . The method according to  claim 41 , wherein the stirring of the pulsator from side to side comprises:
 rotating the pulsator in one direction for a first time;   stopping the pulsator for a second time after the pulsator rotates in one direction;   rotating the pulsator in an opposite direction for the first time when the second time elapses; and   stopping the pulsator for the second time after the pulsator rotates in the opposite direction.   
     
     
         43 . The method according to  claim 42 , further comprising:
 counting the number of operating times of stirring the pulsator from side to side;   comparing the counted number of times of stirring with a defined reference number of times of stirring; and   stopping the stirring operation of the pulsator from side to side when the number of times of stirring is the reference number of times of stirring or more.   
     
     
         44 . The method according to  claim 43 , wherein the reference number of times of stirring is at least one or more. 
     
     
         45 . The method according to  claim 42 , further comprising rotating the pulsator by a motor, wherein the pulsator is driven in a forward direction or a backward direction for the first time while maintaining the motor at a predetermined RPM during the stirring of the pulsator from side to side. 
     
     
         46 . The method according to  claim 45 , further comprising detecting a weight of the cloth before supplying water to the washing tub, wherein the balance cycle is carried out after the weight of the cloth is detected. 
     
     
         47 . The method according to  claim 46 , wherein the detecting of the weight of the cloth is performed using a time taken for the motor to reach a predetermined duty while the motor is running at a weight detection RPM. 
     
     
         48 . The method according to  claim 47 , wherein the predetermined RPM has a value different from the weight detection RPM. 
     
     
         49 . The method according to  claim 47 , wherein the predetermined RPM has a value larger than the weight detection RPM. 
     
     
         50 . The method according to  claim 47 , wherein the number of times of stirring has a value larger than the number of times of weight detection. 
     
     
         51 . A method of controlling a washing machine including a washing tub accommodating cloth and a pulsator rotatably installed in the washing tub, the method comprising:
 supplying water to the washing tub for washing; and   rotating the pulsator to perform washing after supplying water,   wherein a balance cycle is carried out by stirring the washing tub from side to side so as to uniformly distribute the cloth before supplying water to the washing tub.   
     
     
         52 . The method according to  claim 51 , wherein the stirring of the pulsator from side to side comprises:
 rotating the washing tub in one direction for a fifth time;   stopping the washing tub for a sixth time after the washing tub rotates in one direction;   rotating the washing tub in an opposite direction for the fifth time when the sixth time elapses; and   stopping the washing tub for the sixth time after the washing tub rotates in the opposite direction.   
     
     
         53 . The method according to  claim 52 , further comprising:
 counting the number of operating times of stirring the washing tub from side to side;   comparing the counted number of times of stirring with a defined reference number of times of stirring; and   stopping the operation of stirring the washing tub from side to side when the number of times of stirring is the reference number of times of stirring or more.   
     
     
         54 . The method according to  claim 53 , wherein the reference number of times of stirring is at least one or more. 
     
     
         55 . The method according to  claim 52 , further comprising rotating the pulsator by a motor, wherein the washing tub is driven in a forward direction or a backward direction for the fifth time while maintaining the motor at a predetermined RPM during the stirring of the washing tub from side to side. 
     
     
         56 . The method according to  claim 55 , further comprising detecting a weight of the cloth before supplying water to the washing tub, wherein the balance cycle is carried out after the weight of the cloth is detected.