Washing machine and control method thereof

Abstract

Disclosed herein are a washing machine that may effectively remove residual water remaining at the bottom of a tub after completion of washing, and a control method thereof. A drainage motor is driven to remove residual water remaining at the bottom of a tub when a predetermined time elapses after all washing operations are completed. Thereby, the residual water may be prevented from freezing and thus blocking the drain. Further, the residual water may be removed through a control algorithm, without adding a separate device. Thereby, manufacturing costs may be reduced.

What is claimed is: 
     
         1 . A control method of a washing machine including a tub to accommodate water, a drain formed at a bottom of the tub to discharge water, a drainpipe connected to the drain, and a drainage motor installed at the drainpipe to control discharge of the water, the control method comprising:
 determining whether a door of the washing machine is opened after completion of a drying operation;   counting a door open time of the door when determining that the door is opened;   determining whether the counted door open time has reached a first time; and   performing a residual water removal operation of removing residual water at the drain by driving the drainage motor when determining that the door open time has reached the first time.   
     
     
         2 . The control method according to  claim 1 , wherein the residual water removal operation is performed after all operations of the washing machine are completed. 
     
     
         3 . The control method according to  claim 1 , wherein the driving of the draining motor comprises:
 continuously driving the drainage motor.   
     
     
         4 . The control method according to  claim 1 , further comprising:
 counting time for which the drainage motor is driven;   determining whether the counted time has reached a second time; and   stopping the drainage motor when determining that the time has reached a second time.   
     
     
         5 . The control method according to  claim 4 , wherein the first time is set to be longer than the second time. 
     
     
         6 . The control method according to  claim 5 , wherein the first time is at least five minutes. 
     
     
         7 . The control method according to  claim 5 , wherein the second time is at least three seconds. 
     
     
         8 . A washing machine comprising:
 a tub to accommodate water;   a drain formed at a bottom of the tub to discharge water;   a drainpipe connected to the drain;   a drainage motor installed at the drainpipe to control discharge of the water;   a washing tub installed in the tub to accommodate laundry;   a door to open and close an inlet for introduction of the laundry;   a door switch to detect opening or closing of the door;   a controller to count a door open time of the door when determining that the door is opened after completion of a drying operation and to perform a residual water removal operation by driving the drainage motor when determining that the counted door open time has reached a first time.   
     
     
         9 . The washing machine according to  claim 8 , wherein the controller performs the residual water removal operation of removing residual water at the drain by driving the drainage motor for a second time. 
     
     
         10 . The washing machine according to  claim 8 , wherein the controller counts time for which the drainage motor is driven, and when the counted time reaches a second time, stops the drainage motor to stop performing the residual water removal operation. 
     
     
         11 . The washing machine according to  claim 8 , wherein the residual water removal operation is performed after all operations of the washing machine are completed. 
     
     
         12 . A control method of a washing machine including a tub to accommodate water, a drain formed at a bottom of the tub to discharge water, a drainpipe connected to the drain, and a drainage motor installed at the drainpipe to control discharge of the water, the control method comprising:
 determining whether a door of the washing machine is opened;   counting a door open time of the door when determining that the door is opened;   determining whether the counted door open time has reached a first time; and   performing a residual water removal operation of removing residual water at the drain by driving the drainage motor when determining that the door open time has reached the first time,   wherein the residual water removal operation is performed after all operations of the washing machine are completed.   
     
     
         13 . The control method according to  claim 1 , wherein the driving of the draining motor comprises:
 driving the drainage motor by turning the drainage motor on/off.   
     
     
         14 . A washing machine comprising:
 a tub to accommodate water;   a drain formed at a bottom of the tub to discharge water;   a drainpipe connected to the drain;   a drainage motor installed at the drainpipe to control discharge of the water;   a washing tub installed in the tub to accommodate laundry;   a door to open and close an inlet for introduction of the laundry;   a door switch to detect opening or closing of the door;   a check switched to detected if the wash tub has been moved while the door is opened;   a controller determines if the check switch is turned on while the door is open and to count a door open time of the door when determining that the door is opened after the check switch is turn on, to perform a residual water removal operation by driving the drainage motor when determining that the counted door open time has reached a first time.