초록 ▼

A heating control apparatus in microwave ovens controls heating of food by detecting water vapor generated by heating a food to sense a varying relative humidity by a humidity sensor and determining a critical point of the heating condition of the food by detecting a time point when the relative hum

A heating control apparatus in microwave ovens controls heating of food by detecting water vapor generated by heating a food to sense a varying relative humidity by a humidity sensor and determining a critical point of the heating condition of the food by detecting a time point when the relative humidity rises from a minimum value beyond a predetermined threshold value thereby to determine a proper total heating time of the food. To allow accurate humidity sensing, a cleaning device is provided in proximity to the humidity sensor such that the cleaning device is actuated for an appropriate time period at a proper timing to insure proper performance of the humidity sensor.

대표청구항 ▼

A heating control apparatus comprising: heating means for heating food; humidity sensor means for detecting relative humidity, said relative humidity having a minimum value and changing with the amount of water vapor emanating from said food as said food is heated; humidity change detecting means co

A heating control apparatus comprising: heating means for heating food; humidity sensor means for detecting relative humidity, said relative humidity having a minimum value and changing with the amount of water vapor emanating from said food as said food is heated; humidity change detecting means connected to said humidity sensor means for detecting when an abrupt rise occurs in the value of relative humidity with respect to said minimum relative humidity value, the output of said humidity change detecting means being substantially unaffected by changes in the surrounding temperature and humidity conditions, said humidity change detecting means detecting when said relative humidity has risen by a predetermined threshold value from said minimum relative humidity value, said humidity change detecting means including, an amplifier circuit for amplifying the output signal of said humidity sensor, a minimum value detector circuit for holding the minimum value of the output signal of said amplifier circuit and providing a difference signal corresponding to the difference between the output of said amplifier cirucit and said minimum value, and a comparator circuit for comparing said difference signal with said predetermined threshold value, said comparator circuit providing a signal when said difference signal reaches said predetermined threshold value; and heating time determining means connected to said humidity change detecting means for determining the total heating time including an additional heating time which commences after said humidity change detecting means detects that the change in the relative humidity has reached the predetermined threshold value.