Refrigerator and method for controlling the same

Abstract

The present invention relates to refrigerators, and more particularly, to a refrigerator which can measure an amount of frost on an evaporator in real time and determine a frost removing time; and a method for controlling the same. The refrigerator includes a body having at least one storage space for low temperature storage, a compressor in the body for compressing refrigerant, an evaporator for making heat exchange between the refrigerant from the compressor and air in the storage space, a frost removal heater for removing frost from the evaporator, an optical sensor having a light emitting unit for directing a light to the evaporator and a light receiving unit for receiving the light from the light emitting unit, and a control unit for controlling operation of the frost removal heater with reference to a quantity of the light received at the light receiving unit.

1 . A refrigerator comprising:
 a body having at least one storage space for low temperature storage;   a compressor in the body for compressing refrigerant;   an evaporator for making heat exchange between the refrigerant from the compressor and air in the storage space;   a frost removal heater for removing frost from the evaporator;   an optical sensor having a light emitting unit for directing a light to the evaporator and a light receiving unit for receiving the light from the light emitting unit; and   a control unit for controlling operation of the frost removal heater with reference to a quantity of the light received at the light receiving unit.   
     
     
         2 . The refrigerator as claimed in  claim 1 , wherein the optical sensor is arranged over or under the evaporator. 
     
     
         3 . The refrigerator as claimed in  claim 2 , wherein the control unit puts the frost removal heater into operation only if the quantity of the light received at the light receiving unit is the same or greater than a reference value. 
     
     
         4 . The refrigerator as claimed in  claim 1 , wherein the optical sensor is arranged such that the evaporator is positioned between the light emitting unit and the light receiving unit. 
     
     
         5 . The refrigerator as claimed in  claim 4 , wherein the control unit puts the frost removal heater into operation only if the quantity of the light received at the light receiving unit is the same or smaller than a reference value. 
     
     
         6 . The refrigerator as claimed in  claim 1 , wherein the light emitting unit of the optical sensor includes an infrared light emitting diode. 
     
     
         7 . The refrigerator as claimed in  claim 1 , further comprising a bracket which connects the optical sensor to the evaporator. 
     
     
         8 . The refrigerator as claimed in  claim 7 , wherein the bracket includes;
 a body which is extended in a vertical direction of the evaporator and has at least one slot for placing the tube therein, and   a mounting portion which is bent inward from an end of the body for mounting the optical sensor thereto such that the optical sensor faces the evaporator.   
     
     
         9 . The refrigerator as claimed in  claim 8 , wherein the bracket has an angle shaped section. 
     
     
         10 . The refrigerator as claimed in  claim 8 , wherein the control unit puts the frost removal heater into operation only if the quantity of the light received at the light receiving unit is greater than a reference value. 
     
     
         11 . The refrigerator as claimed in  claim 7 , wherein the bracket includes;
 a body which is extended in a vertical direction of the evaporator and has at least one slot for placing the tube therein, and   mounting portions which are bent inward from both ends of the body for mounting the optical sensor thereto such that the optical sensor faces the evaporator.   
     
     
         12 . The refrigerator as claimed in  claim 11 , wherein the body has one end with the light emitting unit mounted thereto and the other end with the light receiving unit mounted thereto. 
     
     
         13 . The refrigerator as claimed in  claim 11 , wherein the bracket has a channel shaped section. 
     
     
         14 . The refrigerator as claimed in  claim 11 , wherein the control unit puts the frost removal heater into operation only if the quantity of the light received at the light receiving unit is the same or smaller than a reference value. 
     
     
         15 . A method for controlling a refrigerator comprising the steps of:
 (a) directing a light to an evaporator;   (b) receiving the light passed through the evaporator; and   (c) removing frost with reference to a quantity of the light received thus.   
     
     
         16 . The method as claimed in  claim 15 , wherein the step (a) includes the step of directing a light with an infrared light emitting diode. 
     
     
         17 . The method as claimed in  claim 15 , wherein the step (b) includes the step of receiving a light reflected at the evaporator. 
     
     
         18 . The method as claimed in  claim 17 , wherein the step (c) includes the step of removing the frost that is performed if the quantity of the light reflected thus is the same or greater than a reference value. 
     
     
         19 . The method as claimed in  claim 15 , wherein the step (b) includes the step of receiving a light passed through the evaporator. 
     
     
         20 . The method as claimed in  claim 19 , the step (c) includes the step of removing the frost that is performed if the quantity of the light passed thus is the same smaller than a reference value.