Washing machine and washing method

Abstract

A washing machine and a washing method thereof are disclosed, in which waste of washing water is reduced and washing efficiency is improved. The washing method includes the steps of determining the volume of laundry in a tub, setting a first water level for a preliminary washing stroke and a second water level for a main washing stroke based on the determined volume of laundry, carrying out the preliminary washing stroke using washing water of the first water level and steam, and converting the preliminary washing stroke into the main washing stroke based on washing water of the second water level depending on an inner temperature of the tub.

1 . A washing method comprising the steps of: 
 determining the volume of laundry in a tub;    setting a first water level for a preliminary washing stroke and a second water level for a main washing stroke based on the determined volume of laundry;    carrying out the preliminary washing stroke using washing water of the first water level and steam; and    converting the preliminary washing stroke into the main washing stroke based on washing water of the second water level depending on an inner temperature of the tub.    
   
   
       2 . The washing method as claimed in  claim 1 , wherein the second water level for the main washing stroke is higher than the first water level for the preliminary washing stroke.  
   
   
       3 . The washing method as claimed in  claim 1 , further comprising the step of setting a driving duration of a steam generator that generates steam and the volume of washing water supplied to the steam generator.  
   
   
       4 . The washing method as claimed in  claim 1 , wherein the step of carrying out the preliminary washing stroke using washing water of the first water level and steam includes the steps of: 
 determining whether the washing water of the first water level decreases; and    resupplying the washing water into the tub if the washing water of the first water level decreases.    
   
   
       5 . The washing method as claimed in  claim 1 , wherein the step of converting the preliminary washing stroke into the main washing stroke depending on the inner temperature of the tub includes the step of stopping the steam generator from steaming if the inner temperature of the tub is higher than a reference temperature.  
   
   
       6 . The washing method as claimed in  claim 5 , wherein the reference temperature is set based on the volume of laundry.  
   
   
       7 . A washing machine comprising: 
 a temperature sensor sensing an inner temperature of a tub;    a steam generator supplying steam into the tub; and    a controller setting a first water level for a preliminary washing stroke and a second water level for a main washing stroke based on the volume of laundry in the tub, and converting the preliminary washing stroke based on washing water of the first water level and the steam into the main washing stroke based on washing water of the second water level depending on the inner temperature of the tub.    
   
   
       8 . The washing machine as claimed in  claim 7 , wherein the controller sets the second water level to be higher than the first water level.  
   
   
       9 . The washing machine as claimed in  claim 7 , wherein the controller further sets a driving duration of the steam generator and the volume of washing water supplied to the steam generator based on the volume of laundry.  
   
   
       10 . The washing machine as claimed in  claim 7 , wherein the controller determines whether the washing water of the first water level decreases during the preliminary washing stroke and resupplies the washing water into the tub if the washing water of the first water level decreases.  
   
   
       11 . The washing machine as claimed in  claim 7 , wherein the controller stops the steam generator from steaming if the inner temperature of the tub is higher than a reference temperature and converts the preliminary washing stroke into the main washing stroke.  
   
   
       12 . The washing machine as claimed in  claim 11 , wherein the controller sets the reference temperature based on the volume of laundry.  
   
   
       13 . A washing method comprising the steps of: 
 determining the volume of laundry in a tub;    setting a first water level for a preliminary washing stroke, a second water level for a main washing stroke, a preliminary washing duration, and a main washing duration based on the determined volume of laundry;    carrying out the preliminary washing stroke using washing water of the first water level and steam during the preliminary washing duration; and    converting the preliminary washing stroke into the main washing stroke based on washing water of the second water level during the main washing duration.    
   
   
       14 . The washing method as claimed in  claim 13 , wherein the second water level for the main washing stroke is higher than the first water level for the preliminary washing stroke.  
   
   
       15 . The washing method as claimed in  claim 13 , further comprising the step of setting a driving duration of a steam generator that generates steam and the volume of washing water supplied to the steam generator.  
   
   
       16 . The washing method as claimed in  claim 13 , wherein the step of carrying out the preliminary washing stroke using washing water of the first water level and steam during the preliminary washing duration includes the steps of: 
 repeatedly determining whether the washing water of the first water level decreases; and    resupplying the washing water into the tub if the washing water of the first water level decreases.    
   
   
       17 . A washing machine comprising: 
 a water level sensor sensing a water level in a tub;    a steam generator supplying steam into the tub; and    a controller setting a first water level for a preliminary washing stroke, a second water level for a main washing stroke, a preliminary washing duration and a main washing duration based on the volume of laundry in the tub, and sequentially carrying out the preliminary washing stroke based on washing water of the first water level and the steam during the preliminary washing duration and the main washing stroke based on washing water of the second water level during the main washing duration.    
   
   
       18 . The washing machine as claimed in  claim 17 , wherein the controller sets the second water level to be higher than the first water level.  
   
   
       19 . The washing machine as claimed in  claim 17 , wherein the controller further sets a driving duration of the steam generator and the volume of washing water supplied to the steam generator based on the volume of laundry.  
   
   
       20 . The washing machine as claimed in  claim 17 , wherein the controller determines whether the washing water of the first water level decreases during the preliminary washing stroke and resupplies the washing water into the tub if the washing water of the first water level decreases.