Washing machine and control method thereof

Abstract

Disclosed herein are a washing machine that detects the weight of laundry based on the displacement of a rotary tub and a control method thereof. The washing machine includes a rotary tub displaced according to the weight of laundry, at least one sensor module to detect the displacement of the rotary tub, and a controller to calculate the weight of the laundry according to the displacement of the rotary tub. The weight of the laundry is sensed according to the displacement of the rotary tub in which the laundry is directly placed.

1 . A washing machine, comprising:
 a rotary tub displaced according to weight of laundry;   at least one sensor module to detect displacement of the rotary tub; and   a controller to calculate the weight of the laundry according to the displacement of the rotary tub.   
     
     
         2 . The washing machine according to  claim 1 , further comprising:
 a water tub in which the rotary tub is provided, wherein   the sensor module is mounted at a front upper end of the water tub inside the water tub.   
     
     
         3 . The washing machine according to  claim 1 , further comprising:
 a water tub in which the rotary tub is provided, wherein   the sensor module is mounted at a rear upper end of the water tub inside the water tub.   
     
     
         4 . The washing machine according to  claim 1 , wherein the sensor module comprises a light source to irradiate light to the rotary tub and an image sensor to receive the irradiated light to sense an image. 
     
     
         5 . The washing machine according to  claim 4 , wherein the sensor module further comprises an image processor to detect displacement of the rotary tub according to the image sensed by the image sensor. 
     
     
         6 . The washing machine according to  claim 4 , wherein the image has a pattern. 
     
     
         7 . The washing machine according to  claim 5 , wherein the image sensor senses an images of one side of the rotary tub when laundry is in the rotary tub, and the image processor compares the sensed image with a reference image to detect the displacement of the rotary tub. 
     
     
         8 . The washing machine according to  claim 1 , wherein the sensor module comprises a plurality of sensor modules mounted at a water tub in which the rotary tub is provided, and the controller averages or sums displacements of the rotary tubs detected by the sensor modules to calculate the weight of the laundry. 
     
     
         9 . The washing machine according to  claim 1 , wherein the sensor module comprises a light emitting part to irradiate light to the rotary tub and a light receiving part to receive light reflected from the rotary tub. 
     
     
         10 . The washing machine according to  claim 9 , wherein the sensor module irradiates light to the rotary tub and receives light reflected from the rotary tub before and after the laundry is put into the rotary tub. 
     
     
         11 . The washing machine according to  claim 10 , wherein the controller compares light amounts received before and after the laundry is put into the rotary tub to calculate the weight of the laundry. 
     
     
         12 . The washing machine according to  claim 7 , wherein the reference image sensed without having laundry in the rotary tub. 
     
     
         13 . The washing machine according to  claim 1 , further comprising:
 a memory to store the weight of the laundry according to the displacement of the rotary tub, wherein   the controller receives information on the weight of the laundry according to the displacement of the rotary tub from the memory to calculate the weight of the laundry.   
     
     
         14 . A control method of a washing machine, comprising:
 irradiating light to a rotary tub which is displaced according to weight of laundry;   receiving light reflected from the rotary tub to detect displacement of the rotary tub; and   calculating the weight of the laundry according to the displacement of the rotary tub.   
     
     
         15 . The control method according to  claim 14 , wherein irradiating light to a rotary tub which is displaced according to weight of laundry comprises irradiating light to the rotary tub before and after the laundry is put into the rotary tub. 
     
     
         16 . The control method according to  claim 15 , wherein receiving light reflected from the rotary tub to detect displacement of the rotary tub comprises receiving light reflected from the rotary tub when the laundry is put into the rotary tub to detect an image of the rotary tub and comparing the images of the rotary tub when the laundry is in the rotary tub with a reference image to detect the displacement of the rotary tub. 
     
     
         17 . The control method according to  claim 16 , wherein the reference image detected without having laundry in the rotary tub. 
     
     
         18 . The control method according to  claim 15 , wherein receiving light reflected from the rotary tub to detect displacement of the rotary tub comprises measuring light amounts reflected from the rotary tub when the laundry is in the rotary tub and comparing the light with a reference light amount to detect the displacement of the rotary tub. 
     
     
         19 . The control method according to  claim 18 , wherein the reference light amount is detected without having laundry in the rotary tub.