Patent ID: 7975338

Claim:
An automatic drying method for a drum type washing machine and dryer having an upper temperature sensor A 1 and a lower temperature sensor A 2 mounted at upper and lower portions of an inside of a duct that is an air circulating passage for drying laundry, respectively, for performing a drying cycle by using a difference of temperatures sensed at the upper temperature sensor A 1 and the lower temperature sensor A 2 , respectively, the method comprising: upon starting the drying cycle, determining whether a temperature at an inside of a tub is higher than a first reference set temperature T 1 ; when the temperature at the inside of the tub is higher than the first reference set temperature T 1 , determining a temperature difference TA 1 -TA 2 between temperatures TA 1 and TA 2 , wherein TA 1 is sensed at the upper temperature sensor A 1 and TA 2 is sensed at the lower temperature sensor A 2 , respectively; and assuming a laundry amount that is proportional to a time period starting from when a drying operation is initiated to when a temperature difference of TA 1 -TA 2 becomes a second reference set temperature.