Washing machine with improved balancing characteristics and control method thereof

Abstract

A washing machine with improved balancing characteristics includes a drum; a motor configured to rotate the drum; and a memory configured to store a no-load imbalance value of the washing machine and a threshold load imbalance value of the washing machine, wherein the no-load imbalance value is measured from an imbalance occurring during a rotation of the drum having no laundry therein. Further, the washing machine includes a control unit configured to calculate the threshold load imbalance value using the measured no-load imbalance value, compare an actual load imbalance value with the threshold load imbalance value and determine whether to stop a rotation of the drum based on the comparison, wherein the actual load imbalance value is determined from an imbalance occurring during a rotation of the drum having laundry therein.

What is claimed is: 
     
         1 . A drum type washing machine comprising:
 a drum;   a motor configured to rotate the drum;   a memory configured to store a no-load imbalance value of the washing machine and a threshold load imbalance value of the washing machine, wherein the no-load imbalance value is measured from an imbalance occurring during a rotation of the drum having no laundry in it; and   a control unit configured to calculate the threshold load imbalance value using the measured no-load imbalance value, and compare an actual load imbalance value with the threshold load imbalance value and determine whether to stop a rotation of the drum based on the comparison, wherein the actual load imbalance value is determined from an imbalance occurring during rotation of the drum having laundry therein.   
     
     
         2 . The washing machine of  claim 1 , wherein control unit calculates the threshold load imbalance value by subtracting the no-load imbalance value from a maximum load imbalance value of the washing machine. 
     
     
         3 . The washing machine of  claim 2 , wherein the maximum load imbalance value is a pre-determined value in accordance with a specification for the washing machine. 
     
     
         4 . The washing machine of  claim 3 , wherein the maximum load imbalance value is a limit beyond which the washing machine cannot withstand any more the imbalance occurring during rotation of the drum having laundry therein. 
     
     
         5 . The washing machine of  claim 3 , wherein other washing machines are manufactured according to the specification. 
     
     
         6 . The washing machine of  claim 5 , wherein the no-load imbalance value is equal to or different from that of another washing machine manufactured according the specification. 
     
     
         7 . The washing machine of  claim 6 , wherein the no-load imbalance value depends on characteristics of a motor in the washing machine and tolerance variations in manufacturing and assembling of the washing machine. 
     
     
         8 . A method for calculating a threshold imbalance value of a drum type washing machine comprising:
 measuring a no-load imbalance value from an imbalance occurring during a rotation of a drum having no laundry therein;   setting the no-load imbalance value as an offset value to adjust a threshold load imbalance value of the washing machine;   calculating the threshold load imbalance value of the washing machine using the no-load imbalance value; and   storing the calculated threshold load imbalance value.   
     
     
         9 . The method of  claim 8 , wherein calculating the threshold load imbalance value comprises:
 reading a maximum load imbalance value of the washing machine; and   subtracting the no-load imbalance value from the maximum load imbalance value.   
     
     
         10 . The method of  claim 9 , wherein the maximum load imbalance value of the washing machine is a pre-determined value in accordance with a specification for the washing machine. 
     
     
         11 . The method of  claim 10 , wherein the maximum load imbalance value is a limit beyond which the washing machine cannot withstand any more the imbalance occurring during rotation of the drum having laundry therein. 
     
     
         12 . The method of  claim 10 , wherein other washing machines are manufactured according to the specification. 
     
     
         13 . The method of  claim 8 , wherein the no-load imbalance value of the washing machine equals or is different from that of another washing machine manufactured in accordance with the specification. 
     
     
         14 . The method of  claim 13 , wherein the no-load imbalance value depends on characteristics of a motor of the washing machine and tolerance variations in manufacturing and assembling the washing machine.