Heating apparatus of washing machine and control method thereof

Abstract

A heating apparatus of a washing machine comprises: a steam generator for generating steam; and a spray nozzle for spraying steam generated from the steam generator into a tub, in which a water level sensor for detecting a level of water supplied for steam generation step by step is mounted at the steam generator. According to this, an entire size of the washing machine is reduced, an amount of washing water is reduced, and a water level inside the steam generator is detected more accurately, thereby enhancing a performance of the heating apparatus.

1 . A heating apparatus of a washing machine comprising: 
 a steam generator for generating steam; and    a spray nozzle for spraying steam generated from the steam generator into a tub,    in which a water level sensor for detecting a level of water supplied for steam generation step by step is mounted at the steam generator.    
   
   
       2 . The apparatus of  claim 1 , wherein the steam generator comprises: 
 a hermetic container to which a water supply tube for supplying water and a steam exhaustion tube for exhausting generated steam are respectively connected;    a heater arranged at a bottom of the hermetic container for heating water supplied into the hermetic container; and    a water level sensor mounted in the hermetic container for detecting a level of water supplied into the hermetic container step by step.    
   
   
       3 . The apparatus of  claim 2 , wherein the water level sensor comprises: 
 one common electrode bar;    a plurality of water level detecting electrode bars of different lengths; and    a supporting member for mounting the common electrode bar and the plurality of water level detecting electrode bars with an insulated state.    
   
   
       4 . The apparatus of  claim 3 , wherein the water level detecting electrode bars comprises: 
 a first electrode for detecting a lowest water level; and    a second electrode for detecting a highest water level.    
   
   
       5 . The apparatus of  claim 4 , wherein the first electrode bar has a length for detecting a level of water supplied into the hermetic container that a heater can be immersed in water.  
   
   
       6 . The apparatus of  claim 4 , wherein the second electrode has a length for detecting a water level having a space at an upper portion of the hermetic container in order to generate steam by heating water by the heater.  
   
   
       7 . A heating method of a washing machine comprising: 
 a first step of supplying water into a steam generator;    a second step of detecting whether a level of water supplied into the steam generator has reached a set level;    a third step of turning on a heater and thereby generating steam when the water level has reached a set level in the second step; and    a fourth step of performing a washing operation when steam generated from the steam generator has been supplied into a tub and thereby temperature inside the tub has reached a set temperature in the third step.    
   
   
       8 . The method of  claim 7 , wherein the set level is a highest level of water supplied into the steam generator.  
   
   
       9 . The method of  claim 8 , wherein a voltage between a common electrode bar and a second electrode bar is applied into a controller when the second electrode bar of a water level sensor is in contact with water in the second step.  
   
   
       10 . The method of  claim 7 , further comprising a step of turning off the heater when a water level inside the steam generator is lower than a lowest water level.  
   
   
       11 . The method of  claim 10 , wherein the lowest water level is a water level that a first electrode bar of a water level is in contact with water.  
   
   
       12 . The method of  claim 7 , wherein the set temperature is temperature inside a tub selected by a user.