Icemaker for refrigerators and control method thereof

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.

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.

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.