Icemaker for refrigerators and control method thereof

Abstract

A control method includes receiving an output value from an optical sensor to determine whether an ice bank is full of ice, driving the sensor heater for a first drive time to heat the optical sensor upon determining that the ice bank is full of ice, driving the optical sensor to receive an output value from the optical sensor after lapse of the first drive time, comparing the output value with the output value received to determine whether the ice bank is full of ice to calculate variation of the output value, and driving the sensor heater for a second drive time to heat the optical sensor so that the optical sensor is defrosted if the calculated variation of the output value is equal to or greater than a reference variation.

1 . A control method of an icemaker for refrigerators comprising an optical sensor, comprising a light emitting part and a light receiving part to receive light irradiated from the light emitting part and transmitted through an internal space of an ice bank to store ice, to output a signal according to an intensity of light received by the light receiving part to sense whether the ice bank is full of ice and a sensor heater to heat the optical sensor so that the optical sensor is defrosted, the control method comprising:
 receiving an output value from the optical sensor to determine whether the ice bank is full of ice;   driving the sensor heater for a first drive time to heat the optical sensor upon determining that the ice bank is full of ice;   driving the optical sensor to receive an output value from the optical sensor after lapse of the first drive time;   comparing the output value with the output value received to determine whether the ice bank is full of ice to calculate variation of the output value; and   driving the sensor heater for a second drive time to heat the optical sensor so that the optical sensor is defrosted if the calculated variation of the output value is equal to or greater than a reference variation.   
     
     
         2 . The control method according to  claim 1 , further comprising determining that it has been normally sensed that the ice bank is full of ice and stopping an operation of the icemaker if the calculated variation of the output value is less than the reference variation. 
     
     
         3 . The control method according to  claim 1 , wherein the receiving the output value from the optical sensor to determine whether the ice bank is full of ice comprises:
 determining that the ice bank is full of ice if the received output value is equal to or less than a first reference value;   determining that the ice bank is not full of ice if the received output value is equal to or greater than a second reference value; and   determining that the optical sensor is frosted if the received output value is greater than the first reference value and is less than the second reference value.   
     
     
         4 . The control method according to  claim 3 , further comprising:
 driving the sensor heater for the second drive time to heat the optical sensor upon determining that the optical sensor is frosted; and   determining whether the ice bank is full of ice after lapse of the second drive time.   
     
     
         5 . The control method according to  claim 3 , further comprising:
 driving the sensor heater to heat the optical sensor upon determining that the optical sensor is frosted;   receiving an output value from the optical sensor to determine whether the ice bank is full of ice; and   further driving the sensor heater for the first drive time to heat the optical sensor upon determining that the ice bank is full of ice.   
     
     
         6 . The control method according to  claim 1 , further comprising determining whether the ice bank is full of ice after lapse of the second drive time. 
     
     
         7 . A control method of an icemaker for refrigerators comprising an optical sensor, comprising a light emitting part and a light receiving part to receive light irradiated from the light emitting part and transmitted through an internal space of an ice bank to store ice, to output a signal according to an intensity of light received by the light receiving part to sense whether the ice bank is full of ice and a sensor heater to heat the optical sensor so that the optical sensor is defrosted, the control method comprising:
 receiving an output value from the optical sensor to determine whether the ice bank is full of ice;   driving the sensor heater to heat the optical sensor upon determining that the ice bank is full of ice;   driving the optical sensor to receive an output value from the optical sensor;   comparing the output value with the output value received to determine whether the ice bank is full of ice to calculate variation of the output value; and   further driving the sensor heater for a second drive time to heat the optical sensor so that the optical sensor is defrosted if the calculated variation is equal to or greater than a reference variation.   
     
     
         8 . The control method according to  claim 7 , further comprising:
 determining whether time to drive the sensor heater has exceeded a first drive time if the calculated variation of the output value is less than the reference variation; and   stopping an operation of the icemaker upon determining that the time to drive the sensor heater has exceeded the first drive time.   
     
     
         9 . The control method according to  claim 7 , wherein the receiving the output value from the optical sensor to determine whether the ice bank is full of ice comprises:
 determining that the ice bank is full of ice if the received output value is equal to or less than a first reference value;   determining that the ice bank is not full of ice if the received output value is equal to or greater than a second reference value; and   determining that the optical sensor is frosted if the received output value is greater than the first reference value and is less than the second reference value.   
     
     
         10 . The control method according to  claim 9 , further comprising:
 driving the sensor heater for the second drive time to heat the optical sensor upon determining that the optical sensor is frosted; and   determining whether the ice bank is full of ice after lapse of the second drive time.   
     
     
         11 . The control method according to  claim 9 , further comprising:
 driving the sensor heater to heat the optical sensor upon determining that the optical sensor is frosted;   receiving an output value from the optical sensor to determine whether the ice bank is full of ice; and   further driving the sensor heater for a first drive time to heat the optical sensor upon determining that the ice bank is full of ice.   
     
     
         12 . The control method according to  claim 9 , further comprising determining whether the ice bank is full of ice after lapse of the second drive time. 
     
     
         13 . An icemaker for refrigerators, comprising:
 an optical sensor, comprising a light emitting part and a light receiving part to receive light irradiated from the light emitting part and transmitted through an internal space of an ice bank to store ice, to output a signal according to an intensity of light received by the light receiving part to sense whether the ice bank is full of ice;   a sensor heater to heat the optical sensor so that the optical sensor is defrosted; and   a controller to receive an output value from the optical sensor to determine whether the ice bank is full of ice, to drive the sensor heater for a first drive time to heat the optical sensor upon determining that the ice bank is full of ice, to drive the optical sensor to receive an output value from the optical sensor after lapse of the first drive time, to compare the output value with the output value received to determine whether the ice bank is full of ice to calculate variation of the output value, and to drive the sensor heater for a second drive time to heat the optical sensor so that the optical sensor is defrosted if the calculated variation of the output value is equal to or greater than a reference variation.   
     
     
         14 . An icemaker for refrigerators, comprising:
 an optical sensor, comprising a light emitting part and a light receiving part to receive light irradiated from the light emitting part and transmitted through an internal space of an ice bank to store ice, to output a signal according to an intensity of light received by the light receiving part to sense whether the ice bank is full of ice;   a sensor heater to heat the optical sensor so that the optical sensor is defrosted; and   a controller to receive an output value from the optical sensor to determine whether the ice bank is full of ice, to drive the sensor heater to heat the optical sensor upon determining that the ice bank is full of ice, to drive the optical sensor to receive an output value from the optical sensor, to compare the output value with the output value received to determine whether the ice bank is full of ice to calculate variation of the output value, and to further drive the sensor heater for a second drive time to heat the optical sensor so that the optical sensor is defrosted if the calculated variation is equal to or greater than a reference variation.   
     
     
         15 . The ice maker according to  claim 14 , further comprising an ice making unit to make ice from water supplied thereto, wherein the ice bank disposed below the ice making unit and stores ice separated from the ice making unit. 
     
     
         16 . The ice maker according to  claim 15 , further comprising:
 an ice feeder installed in the ice bank to feed ice separated from the ice making unit;   a crushing chamber installed at the front of the ice bank, the crushing chamber including an ice crusher to selectively crush the ice fed by the ice feeder.   
     
     
         17 . The ice maker according to  claim 16 , wherein the ice feeder includes a spiral auger rotated by a feeding motor to feed the ice stored in the ice bank to the crushing chamber. 
     
     
         18 . The ice maker according to  claim 17 , wherein the ice crusher includes a stationary blade and a rotary blade installed at the end of the auger.