Washing machine and control method thereof

Abstract

A washing machine and a control method thereof capable of accurately detecting the weight of laundry received in the washing machine by primarily detecting the weight of the laundry according to driving of a motor before the beginning of a washing process and correcting the primary detected weight of laundry according to the number of supplies of water which is additionally supplied within a given time after main water supply is completed during the washing process.

What is claimed is: 
     
         1 . A control method of a washing machine comprising a tub to store water, a drum installed inside the tub to accommodate laundry, and a motor to rotate the drum, comprising:
 detecting weight of laundry by driving the motor before water is supplied to the tub;   supplying water to a water level set according to the detected weight of laundry;   detecting a water level changed according to rotation of the drum after water is supplied to the tub to determine whether or not it is a water resupply condition;   resupplying water to a level of water resupply when it is determined to be the water resupply condition; and   correcting the detected weight of laundry according to the number of resupplies of water.   
     
     
         2 . The control method according to  claim 1 , wherein the detecting weight of laundry comprises primarily detecting weight of laundry by driving the motor before the beginning of a washing process and using an acceleration time taken when the drum reaches a certain speed. 
     
     
         3 . The control method according to  claim 1 , wherein the detecting a change in water level comprises detecting a level of water in the tub changed according to agitation and rotation of the drum during a washing process. 
     
     
         4 . The control method according to  claim 3 , wherein the change in water level is proportional to the weight of laundry. 
     
     
         5 . The control method according to  claim 3 , wherein the determining whether or not it is a water resupply condition comprises detecting a water level lowered as laundry absorbs water by agitating and rotating the drum during the washing process to determine whether or not the water level is a water level required for water resupply. 
     
     
         6 . The control method according to  claim 1 , further comprising:
 counting a generation time of the water resupply; and   counting the number of generations of water resupply until the counted time elapses over a given time.   
     
     
         7 . The control method according to  claim 6 , wherein the number of resupplies of water is proportional to the weight of laundry. 
     
     
         8 . The control method according to  claim 6 , further comprising:
 classifying the number of resupplies of water by the weight of laundry to store the same; and   correcting the weight of laundry by a load higher than the detected weight of laundry when the counted number of resupplies of water is the reference number or more.   
     
     
         9 . A washing machine comprising:
 a tub to store water;   a water supply unit to supply water to the tub;   a drum installed inside the tub to accommodate laundry;   a motor to rotate the drum; and   a control unit which controls the motor before water is supplied to the tub to detect weight of laundry, controls the water supply unit according to the detected weight of laundry to supply water to a set water level, rotates the drum after water is supplied to the tub to detect a change in water level, counts the number of resupplies of water according to the change in water level, and corrects the detected weight of laundry according to the number of resupplies of water.   
     
     
         10 . The washing machine according to  claim 9 , wherein the control unit controls the motor before the beginning of a washing process to primarily detect weight of laundry using an acceleration time taken when the drum reaches a certain speed. 
     
     
         11 . The washing machine according to  claim 9 , wherein the control unit detects a level of water in the tub changed according to agitation and rotation of the drum during a washing process. 
     
     
         12 . The washing machine according to  claim 11 , wherein the control unit detects a water level lowered as laundry absorbs water by agitating and rotating the drum during the washing process to determine whether or not the water level is a water level required for water resupply. 
     
     
         13 . The washing machine according to  claim 9 , wherein the control unit further comprises:
 counting a generation time of the water resupply; and   counting the number of generations of water resupply until the counted time elapses over a given time.   
     
     
         14 . The washing machine according to  claim 13 , wherein the control unit further comprises:
 classifying the number of resupplies of water by the weight of laundry to store the same; and   correcting the weight of laundry by a load higher than the detected weight of laundry when the counted number of resupplies of water is the reference number or more.   
     
     
         15 . A method of detecting a weight of laundry in a washing machine, comprising:
 first detecting the weight of the laundry by driving a motor before water is supplied to a tub of the washing machine;   subsequently supplying water to a water level set according to the first detected weight of laundry;   detecting a water level changed according to rotation of a drum of the washing machine after water is supplied to the tub to determine whether or not it is a water resupply condition;   resupplying water to a level of water resupply when it is determined to be the water resupply condition; and   correcting the first detected weight of laundry according to the number of resupplies of water.   
     
     
         16 . The method according to  claim 15 , further comprising performing a washing process,
 wherein the first detecting the weight of the laundry is performed before the beginning of the washing process.   
     
     
         17 . The method according to  claim 16 , wherein the detecting the change in water level is performed during the washing process. 
     
     
         18 . The method according to  claim 17 , wherein the change in water level is proportional to the weight of the laundry. 
     
     
         19 . The control method according to  claim 17 , wherein the determining whether or not it is a water resupply condition comprises detecting a water level lowered as laundry absorbs water by agitating and rotating the drum during the washing process to determine whether or not the water level is a water level required for water resupply. 
     
     
         20 . The method according to  claim 15 , further comprising:
 counting a generation time of the water resupply; and   counting the number of generations of water resupply until the counted time elapses over a given time.