Abstract: A method of controlling the application of heat in a food heating apparatus comprising a first heating-control mode such that the heat is applied to an object to be heated until an infrared detecting device detects that a surface temperature of the object has reached at least one predetermined temperature. A second heating-control mode effects at least one of the first heating mode wherein the heat is turned on and off repeatedly and a second heating mode wherein the output of the heat source is decreased gradually. A third heating-control mode is also provided for terminating the application of heat to the object.

Abstract: A method of food heating control in which the heating time length (.tau..sub.o) from a time point (t.sub.1) when the food temperature changing with the heating thereof reaches a predetermined set value (T.sub.1) to a time point (t.sub.2) when the vapor or gas liberated by heating of the food begins to increase the humidity or gas concentration is used as a basis for automatically determining a subsequent heating time length (.tau..sub.R). Since the time period (.tau..sub.R) for the subsequent heating process is determined by the heating time from the time point when the food temperature reaches a predetermined set value to the time point when the humidity or gas concentration begins to increase (unlike in the prior art method in which the heating time from the start of heating to the time point when humidity begins to increase is used to determine the subsequent heating time), the error in the heating time which otherwise might be caused by the variation in the initial food temperature is obviated.

Abstract: A food heating method and apparatus are disclosed in which a heating time length suitable to the food to be cooked is determined by automatically detecting a change in humidity or concentration of the vapor or gas respectively liberated from the food. The initial temperature of the food is measured, and an additional heating time length is calculated from the measured initial temperature and the heating time length required before the detection of the humidity or gas concentration as the case may be, thus determining a total heating time length for properly cooking up the food.

Abstract: 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.

Abstract: Apparatus for controlling heating time for food placed in a cooking apparatus such as a microwave oven in which heating time required for the humidity of the food which varies with the heating of the food to reach a representative humidity value after abrupt change with a positive gradient is measured, and the product of the measured heating time multiplied by a predetermined heating time coefficient which is inherent in the particular food is added to the measured heating time so that the sum represents the total required heating time for the food.

Abstract: Apparatus for controlling heating time for food placed in a cooking apparatus such as a microwave oven in which heating time required for the humidity of the food which varies with the heating of the food to reach a representative humidity value after abrupt change with a positive gradient is measured, and the product of the measured heating time multiplied by a predetermined heating time coefficient which is inherent in the particular food is added to the measured heating time so that the sum represents the total required heating time for the food.