Washing machine and control method thereof

Abstract

The present invention provides a washing machine and control method thereof, by which a laundry can be dried more effectively, by which a drying cycle time can be shortened, and by which stability and reliance can be enhanced. The present invention includes the step of performing dewatering and preliminary drying simultaneously during a dewatering cycle. And, The present invention supplies cooling water for condensing hot and humid air during the dewatering cycle.

1 . A method of controlling a washing machine, the washing machine including a drum holding a laundry therein, the method comprising the step of performing a dewatering cycle wherein the dewatering cycle comprises at least one preliminary drying period for drying the laundry.  
   
   
       2 . The method of  claim 1 , wherein a heater heating air and a blower fan forcibly supplying the heated air to the drum are provided to the at least one preliminary drying period.  
   
   
       3 . The method of  claim 2 , wherein the heater is controlled to leave a temperature of the heated air within a prescribed range during the at least one preliminary drying period.  
   
   
       4 . The method of  claim 3 , wherein the heater is turned off if the temperature of the heated air is 90° C. and wherein the heater is turned on if the temperature of the heated air is 87° C.  
   
   
       5 . The method of  claim 1 , wherein the at least one preliminary drying period is inserted between a plurality of dewatering periods where the drum is rotated at a plurality of normal dewatering speeds, respectively.  
   
   
       6 . The method of  claim 5 , wherein a plurality of the normal dewatering speeds are 900 rpm and 1,000 rpm, respectively.  
   
   
       7 . The method of  claim 1 , wherein the at least one preliminary drying period exists behind each corresponding period detecting an eccentricity corresponding to a distance between a central axis of the drum and a gravity center of the laundry and a foam of the laundry.  
   
   
       8 . A method of controlling a washing machine, the washing machine including a drum holding a laundry therein, the method comprising the steps of: 
 executing a dewatering cycle and at least one preliminary drying for drying the laundry during the dewatering cycle; and    condensing hot and humid air produced from the drum during at least one portion of the dewatering cycle.    
   
   
       9 . The method of  claim 8 , wherein the condensing step is continuously performed during the dewatering cycle.  
   
   
       10 . The method of  claim 8 , wherein the condensing step is periodically performed during the dewatering cycle.  
   
   
       11 . The method of  claim 8 , wherein the condensing step is continuously performed during the dewatering cycle during the preliminary drying only.  
   
   
       12 . The method of  claim 8 , wherein the condensing step is periodically performed during the dewatering cycle during the preliminary drying only.  
   
   
       13 . A method of controlling a washing machine, the washing machine including a drum holding a laundry therein, the method comprising the step of performing a dewatering cycle by rotating the drum at a plurality of different rotational speeds, the dewatering cycle comprising: 
 a plurality of first periods for detecting both eccentricities and foams by rotating the drum at a low dewatering speed selected from a plurality of the different rotational speeds, respectively;    a plurality of second periods lying between a plurality of the first periods to rotate the drum at normal dewatering speeds selected from a plurality of the different rotational speeds and simultaneously to perform preliminary drying if the eccentricities and foams detected through the first periods are decided as normal, respectively;    a third period lying behind the second periods to finally rotate the drum at a high dewatering speed selected from a plurality of the different rotational speeds; and    a fourth period lying next to the third period to perform an unraveling process of the laundry.    
   
   
       14 . The method of  claim 13 , wherein the low dewatering speed is 600 rpm, each of the normal dewatering speeds is 900 rpm˜1,000 rpm, and the high dewatering speed is 1,400 rpm.  
   
   
       15 . The method of  claim 13 , wherein the preliminary drying is performed by driving a heater heating air and a blower fan forcibly supplying the heated air to the drum.  
   
   
       16 . A washing machine comprising: 
 a drum holding a laundry therein;    a heater heating air to produce hot air;    an air supply path leading the hot air to the drum;    a blower fan forcibly supplying the hot air to the drum via the air supply path; and    a control unit executing a dewatering cycle sub-routine wherein the dewatering cycle sub-routine comprises at least one preliminary drying step of drying the laundry by driving the heater and the blower fan during a dewatering cycle.    
   
   
       17 . The washing machine of  claim 16 , wherein the air supply path is a circulation duct.  
   
   
       18 . The washing machine of  claim 16 , wherein the dewatering cycle sub-routine further comprises the step of condensing hot and humid air produced from the drum during at least one portion of the dewatering cycle.  
   
   
       19 . The washing machine of  claim 16 , further comprising a cooling water inlet pipe supplying a cooling water to condense hot and humid air flowing via the air supply path.  
   
   
       20 . The washing machine of  claim 19 , wherein the cooling water is continuously supplied to the air supply path during the dewatering cycle.  
   
   
       21 . The washing machine of  claim 19 , wherein the cooling water is periodically supplied to the air supply path during the dewatering cycle.  
   
   
       22 . The washing machine of  claim 19 , wherein the cooling water is continuously supplied to the air supply path during a preliminary drying period for the at least one preliminary drying step only.  
   
   
       23 . The washing machine of  claim 19 , wherein the cooling water is periodically supplied to the air supply path during a preliminary drying period for the at least one preliminary drying step only.  
   
   
       24 . The washing machine of  claim 19 , wherein the cooling water is supplied about 0.5 liter per minute.  
   
   
       25 . The washing machine of  claim 16 , wherein the heater is controlled to leave a temperature of the heated air within a prescribed range during a preliminary drying period for the at least one preliminary drying step.  
   
   
       26 . The washing machine of  claim 16 , wherein the heater is turned off if the temperature of the heated air is 90° C. and wherein the heater is turned on if the temperature of the heated air is 87° C.