Washing machine and suds sensing method thereof

Abstract

A washing machine and a suds sensing method thereof, in which a generation of suds is precisely sensed using discharge characteristics of suds in a water discharging operation. The suds sensing method of a washing machine includes determining whether a water level reaches a water discharge completion level in a predetermined water discharging time in a water discharging operation, determining whether the water level reaches a suds sensing level in a predetermined suds discharging time by controlling a drainage device such that the drainage device is turned on and off when the water level does not reach the water discharge completion level in the predetermined water discharging time, and sensing the suds by controlling the drainage device such that the drainage device is turned on and off in a predetermined range of the water level when the water level reaches the suds sensing level in the predetermined suds discharging time.

1 . A suds sensing method of a washing machine comprising: 
 discharging water by determining whether a water level reaches a water discharge completion level in a predetermined water discharging time in a water discharging operation;    discharging suds by controlling a drainage device such that the drainage device is turned on and off when the water level does not reach the water discharge completion level in the predetermined water discharging time; and    sensing the suds by detecting a water level varying according to the turning on and off of the drainage device.    
   
   
       2 . The suds sensing method as set forth in  claim 1 , wherein the predetermined water discharging time is set to a water discharge completion time, which is time taken to discharge the maximum amount of the water during operations of the washing machine.  
   
   
       3 . The suds sensing method as set forth in  claim 1 , wherein, in the discharging of the suds, the drainage device is controlled such that the drainage device is turned on and off during a predetermined time to distinguish between the suds and foreign substances in the drainage device.  
   
   
       4 . The suds sensing method as set forth in  claim 3 , wherein the predetermined time is a suds discharging time, which is time taken to discharge the suds according to the turning on and off of the drainage device.  
   
   
       5 . The suds sensing method as set forth in  claim 4 , wherein the suds discharging time is determined by a volume of the washing machine and a capacity of the drainage device.  
   
   
       6 . The suds sensing method as set forth in  claim 1 , wherein, in the sensing of the suds, it is determined that the water level reaches a suds sensing level in a predetermined suds discharging time according to the turning on and off of the drainage device.  
   
   
       7 . The suds sensing method as set forth in  claim 6 , wherein the drainage device is controlled such that the drainage device is turned on and off in a predetermined range of the water level to distinguish between the suds and the foreign substances in the drainage device, when the water level reaches the suds sensing level in the predetermined suds discharging time.  
   
   
       8 . The suds sensing method as set forth in  claim 7 , wherein the predetermined range of the water level is set to lower than the suds sensing level, and comprises an upper limit and a lower limit for controlling the drainage device such that the drainage device is turned on/off.  
   
   
       9 . The suds sensing method as set forth in  claim 7 , wherein a number of suds-sensing times according to the turning on and off of the drainage device is sensed, and it is determined that suds are generated when the number of suds-sensing times is more than a designated number.  
   
   
       10 . The suds sensing method as set forth in  claim 1 , wherein, in the discharging of the suds, the drainage device is controlled such that the drainage device is turned on/off in a predetermined range of the water level during a predetermined time to distinguish between the suds and the foreign substances in the drainage device.  
   
   
       11 . The suds sensing method as set forth in  claim 10 , wherein the predetermined time is a suds sensing time, which is time taken to sense the suds according to the turning on and off of the drainage device.  
   
   
       12 . A suds sensing method of a washing machine comprising: 
 determining whether a water level reaches a water discharge completion level in a predetermined water discharging time in a water discharging operation;    determining whether the water level reaches a suds sensing level in a predetermined suds discharging time, by controlling a drainage device such that the drainage device is turned on and off when the water level does not reach the water discharge completion level in the predetermined water discharging time; and    sensing the suds by controlling the drainage device such that the drainage device is turned on and off in a predetermined range of the water level when the water level data reaches the suds sensing level in the predetermined suds discharging time.    
   
   
       13 . The suds sensing method as set forth in  claim 12 , wherein the predetermined range of the water level is set lower than the suds sensing level, and comprises an upper limit and a lower limit for controlling the drainage device such that the drainage device is turned on and off.  
   
   
       14 . The suds sensing method as set forth in  claim 13 , wherein a number of suds-sensing times according to the turning on and off of the drainage device is sensed, and it is determined that suds are generated when the number of suds-sensing times is more than a designated number.  
   
   
       15 . A washing machine having a drainage device for discharging washing water and a detergent, comprising: 
 a water level sensing unit to detect a water level varying according to the operation of the drainage device; and    a control unit to determine whether the water level reaches a water discharge completion level in a predetermined water discharging time, discharging suds by controlling the drainage device such that the drainage device is turned on and off when the water level does not reach the water discharge completion level, and to sense the suds by detecting the variation in the water level.    
   
   
       16 . The washing machine as set forth in  claim 15 , wherein the control unit determines whether the water level reaches a suds sensing level in a predetermined suds discharging time according to the turning on and off of the drainage device, and controls the drainage device such that the drainage device is turned on and off in a predetermined range of the water level when the water level reaches the suds sensing level.  
   
   
       17 . A method for sensing suds in a washing machine having a drainage pump, the method comprising: 
 discharging water from the washing machine after a washing or rinsing operation has been performed by turning on the drainage pump;    sensing a generation of suds by detecting whether a water level of the washing machine has reached a water discharge completion level in a predetermined time period;    preliminary suds sensing by controlling the turning on and off of the drainage pump to distinguish between the suds and foreign substances in the drainage pump, when the water level does not reach the water discharge completion level in the predetermined time period;    main suds sensing for controlling the turning on and off of the drainage pump, to distinguish between the suds and the foreign substances in the drainage pump, when the water level reaches the suds sensing level in the predetermined suds discharging time during the performing of the preliminary suds sensing; and    eliminating the suds by repeatedly performing the rinsing operation, a discharging operation and a dehydrating operation of the washing machine.