Washing machine and washing method using an integrated sensing device for water level and rotating unbalance

Abstract

Integrated sensing device for sensing both the water level and the rotating unbalance in a washing machine. The sensing device includes a magnetic sensor coupled to the casing of the washing machine and a magnetic body coupled to the washing tub of the washing machine. The sensed magnetic force indicates a position of the washing tub relative to the casing. While the washing water is supplied, the weight of the washing water causes the washing tub to move to a lower position and thereby the sensed magnetic force decreases. The water supply is shut off once the magnetic force decreases to a first preset value. Moreover, during a spin-drying process, if the sensed magnetic field decreases to a second predetermined value which indicates presence of rotating unbalance, the rotation is stopped and a preliminary spin-drying process is initiated.

What is claimed is: 
     
         1 . A washing machine comprising:
 a casing;   a washing tub disposed inside the casing;   a drive unit configured to rotate the washing tub;   a control panel; and   a magnetic sensing device configured to sense a water level in the washing tub and also configured to sense rotating unbalance of the washing tub.   
     
     
         2 . The washing machine of  claim 1 , wherein the magnetic sensing device comprises:
 a magnetic body coupled to the washing tub; and   a magnetic sensor coupled to the casing and configured to generate a signal representing a distance between the magnetic body and the magnetic sensor.   
     
     
         3 . The washing machine of  claim 1 , wherein the control panel comprises control circuits and is disposed at an upper portion of the casing, and wherein the magnetic sensor is coupled to the control circuits; and wherein the magnetic body is a permanent magnet and disposed at an upper edge of the washing tub. 
     
     
         4 . The washing machine of  claim 3  further comprising a suspension system configured to support the washing tub in a suspended state, wherein a distance between the magnetic sensor and the magnetic body increases with a weight of washing water supplied to the washing tub and laundry loaded in the washing tub. 
     
     
         5 . The washing machine of  claim 3 , wherein the control circuits are configured to shut off water supply to the washing tub or stop rotation of an inner tub of the washing tub based on a signal generated by the magnetic sensor, and wherein the signal indicates an intensity of a magnetic force generated by the magnetic body. 
     
     
         6 . The washing machine of  claim 5 , wherein the control circuits are configured to shut off water supply if the signal indicates an intensity of the magnetic force is equal to or below a first predetermined value. 
     
     
         7 . The washing machine of  claim 6 , wherein the control circuits are configured to stop rotation of the inner tub if the signal indicates an intensity of the magnetic force is equal to or below a second predetermined value. 
     
     
         8 . The washing machine of  claim 1 , wherein the washing tub comprises a stationary outer tub configured to contain washing water, and wherein the inner tub is rotatable and configured to accommodate laundry. 
     
     
         9 . The washing machine of  claim 8 , wherein, upon the rotation of the inner tub being stopped amid a spin-drying process responsive to a signal generated from the magnetic sensor, the washing machine is configured to:
 resupply washing water to the washing tub;   alternately rotate the inner tub clockwise and counter-clockwise; and   drain wash water from the washing tub and reinitiate a spin-drying process.   
     
     
         10 . A method of washing performed by a washing machine, the method comprising:
 supplying washing water to a washing tub;   during said supplying, a magnetic sensor detecting a magnetic force generated by a magnetic body, wherein an intensity of the magnetic force corresponds to a position of the washing tub with reference to a casing of the washing machine;   the magnetic sensor generating a signal indicating the intensity of the magnetic force; and   responsive to the signal indicating the intensity of the magnetic force is equal to or below a first preset reference value, automatically shutting off the water supply.   
     
     
         11 . The method of  claim 10 , wherein the magnetic sensor is stationary and coupled to the casing of the washing machine, wherein the magnetic body is coupled to the washing tub, and wherein the position of the washing tub varies with a washing water level in the washing tub. 
     
     
         12 . The method of  claim 11 , wherein the washing tub is coupled to a suspension system that supports the washing tub in a suspended state. 
     
     
         13 . The method of  claim 10  further comprising performing a washing operation after the water supply is shut off. 
     
     
         14 . A method of washing performed by a washing machine, the method comprising:
 draining washing water from a washing tub of the washing machine;   rotating the washing tub to spin-dry laundry in the washing tub;   detecting an intensity of magnetic force generated by a magnetic body coupled to the washing tub, wherein the intensity of the magnetic force corresponds to a position of the washing tub with reference to a casing of the washing tub;   a magnetic sensor generating a signal based on the detecting; and   automatically stopping the rotation of the washing tub when the intensity of magnetic force is equal to or less than a first preset reference value that corresponds to a rotating unbalance state of the washing tub.   
     
     
         15 . The method of  claim 14  further comprising:
 performing a preliminary spin-drying process after the rotation of the washing tub is stopped, wherein the preliminary spin-drying process comprises: 
 resupply washing water to the washing tub; 
 alternately rotate the washing tub in forward and backward directions; and 
 drain wash water from the washing tub and initiate a spin-drying process.