Washing machine and method of controlling rinsing cycle

Abstract

A washing machine capable of optimizing the rinsing time and the amount of rinsing water by using a conductivity sensor, and a method of controlling a rinsing cycle thereof. When the amount of detergent remaining in the rinsing water is determined to be small according to the measured conductivity, the amount of rinsing water and the rinsing time are minimized, that is, the rinsing water is alternately supplied in stages of times, the conductivity of the rinsing water is measured at the stop of the supply of rinsing water, and if the measured conductivity is below a reference value, the rinsing cycle is stopped and enters to a final-spin dry cycle, so that the water and energy is saved and the rinsing is achieved with the optimum algorithm when laundry having a little contamination and a small amount of detergent is input.

What is claimed is: 
     
         1 . A method of controlling a washing machine provided with a drum, a water tub installed outside the drum to receive rinsing water and a motor to rotate the drum, the method comprising:
 supplying rinsing water in a stepwise manner;   performing a rinsing cycle by alternately rotating the drum according to a drive of the motor during the supplying of rinsing water in a stepwise manner;   measuring a conductivity of the rinsing water during the performing of the rinsing cycle; and   changing a rinsing profile of the rinsing cycle according to the measured conductivity of the rinsing water.   
     
     
         2 . The method of  claim 1 , wherein the supplying of rinsing water in a stepwise manner comprises:
 supplying the rinsing water for a first time that is set to measure the conductivity of the rinsing water; and   supplying the rinsing water for a time that is set in stages to adjust an amount of supply of the rinsing water according to the measured conductivity.   
     
     
         3 . The method of  claim 2 , wherein the first time is a time configured to supply a minimum amount of rinsing water required to measure the conductivity of the rinsing water. 
     
     
         4 . The method of  claim 2 , wherein the time set in stages is a time configured to supply an amount of rinsing water suitable to adjust the amount of supply of the rinsing water. 
     
     
         5 . The method of  claim 2 , wherein the amount of supply of the rinsing water is adjusted to be in proportion to the measured conductivity. 
     
     
         6 . The method of  claim 5 , wherein if the conductivity is large, the amount of supply of the rinsing water is increased so that the conductivity of the rinsing water is rapidly lowered. 
     
     
         7 . The method of  claim 1 , wherein the rinsing cycle performs an alternate supply of water in which the drum is alternately rotated whenever the rinsing water is supplied in a stepwise manner. 
     
     
         8 . The method of  claim 7 , wherein in the measuring of the conductivity of the rinsing water, the conductivity of the rinsing water is measured when the alternate supply of water is stopped. 
     
     
         9 . The method of  claim 8 , wherein the rinsing profile compares the measured conductivity of the rinsing water with a reference value, and finishes the rinsing cycle that is performed through the alternate supply of water if the measured conductivity is below the reference value. 
     
     
         10 . The method of  claim 8 , wherein the rinsing profile compares the measured conductivity of the rinsing water with a reference value, and controls the rinsing cycle that is performed through the alternate supply of water if the measured conductivity is greater than or equal to the reference value. 
     
     
         11 . The method of  claim 10 , wherein in the rinsing cycle performed through the alternate supply of water,
 rinsing water is supplied while adjusting the amount of supply of rinsing water according to the measured conductivity, and   an alternate supply of water is performed in which the drum is alternately rotated when the rinsing water is supplied.   
     
     
         12 . The method of  claim 11 , wherein the amount of supply of the rinsing water is adjusted by supplying rinsing water for the time that is set according to the measured conductivity. 
     
     
         13 . The method of  claim 12 , wherein if the measured conductivity is higher, the time set to supply rinsing water is larger such that a larger amount of the rinsing water is supplied. 
     
     
         14 . The method of  claim 11 , wherein the amount of supply of the rinsing water is adjusted by supplying rinsing water to a water level that is set according to the measured conductivity. 
     
     
         15 . The method of  claim 14 , wherein if the measured conductivity is higher, the water level set to supply rinsing water is larger such that a larger amount of the rinsing water is supplied. 
     
     
         16 . A washing machine comprising:
 a water tub;   a water supply apparatus configured to supply the water tub with rinsing water;   a conductivity sensor configured to measure a conductivity of the rinsing water; and   a control part, at a rinsing cycle, configured to supply the water tub with the rinsing water in a stepwise manner by controlling the water supply apparatus, and to change a rinsing profile of the rinsing cycle according to the conductivity of the rinsing water that is measured by the conductivity sensor.   
     
     
         17 . The washing machine of  claim 16 , wherein the water supply apparatus supplies the rinsing water in a stepwise manner according to a control of the control part,
 wherein the water supply apparatus supplies the rinsing water for a first time that is set in the control part so as to measure the conductivity of the rinsing water, and   supplies the rinsing water for a time that is set in stages in the control part so as to adjust an amount of supply of the rinsing water according to the measured conductivity.   
     
     
         18 . The washing machine of  claim 17 , wherein the control part adjusts the amount of supply of the rinsing water that is to be in proportion to the measured conductivity. 
     
     
         19 . The washing machine of  claim 18 , wherein the control part controls, if the conductivity is large, the amount of supply of the rinsing water is increased so that the conductivity of the rinsing water is rapidly lowered. 
     
     
         20 . The washing machine of  claim 16 , further comprising a motor to rotate the drum,
 wherein the control part performs the rinsing cycle by alternately rotating the drum according to the driving of the motor during the supplying of water in a stepwise manner.   
     
     
         21 . The washing machine of  claim 20 , wherein the conductivity sensor measures a conductivity of the rinsing water that is changed through the alternate supply of water. 
     
     
         22 . The washing machine of  claim 21 , wherein the control part compares the measured conductivity of the rinsing water with a reference value, and if the measured conductivity is below the reference value, changes the rinsing profile to finish the rinsing cycle that is performed through the alternate supply of water. 
     
     
         23 . The washing machine of  claim 21 , wherein the control part compares the measured conductivity of the rinsing water with a reference value, and if the measured conductivity is greater than or equal to the reference value, changes the rinsing profile to control the rinsing cycle that is performed through the alternate supply of water. 
     
     
         24 . The washing machine of  claim 23 , wherein the control part controls the water supply apparatus to adjust an amount of supply of the rinsing water according to the measured conductivity. 
     
     
         25 . The washing machine of  claim 24 , wherein the control part controls to adjust an amount of supply of the rinsing water during a time that is set according to the measured conductivity. 
     
     
         26 . The washing machine of  claim 25 , wherein if the measured conductivity is higher, the control part controls the time, which is set to supply the rinsing water, to be larger such that a larger amount of the rinsing water is supplied. 
     
     
         27 . The washing machine of  claim 24 , wherein the control part adjusts the amount of supply of the rinsing water to a water level that is set according to the measured conductivity. 
     
     
         28 . The washing machine of  claim 27 , wherein if the measured conductivity is higher, the water level is set to be larger such that a larger amount of the rinsing water is supplied.