Abstract: A heating apparatus such as microwave ovens includes a heating chamber having a door, heaters for heating food contained in the heating chamber, a temperature sensor for sensing a temperature in the heating chamber to provide an output in accordance with the sensed temperature, a gas sensor sensing a volume of gas in the heating chamber to provide an output in accordance with the sensed gas volume, and a microcomputer-based control device. The control device sets a reference value in accordance with the output of the temperature sensor, the reference value being for determining the kind of the food. The control device further calculates a change rate of the gas volume on the basis of the output of the gas sensor. The control device then compares the change rate of the gas volume with the reference value to determine the kind of the food contained in the heating chamber.

Abstract: A microwave oven may perform an induction heating mode, dielectric heating mode, and induction/dielectric switch heating mode. The invention is adapted to a microwave oven, in which an induction coil is mounted on the outer bottom wall of a heating chamber, and a heat insulation member is mounted on the induction coil. The microwave oven comprises an induction heating section including an induction coil, a dielectric heating section including a magnetron, a power supply section for generating high frequency power by switching D.C. power obtained by rectifying commercial A.C. power, the power supply section including a power transistor for switching the D.C.

Abstract: A control apparatus and method for a microwave oven capable of fixing an optimum thawing time, coping with unexpected voltage variation of an input AC source. According to the aforesaid apparatus and method, a weight factor corresponding to an input source voltage variation is found, a thawing time proportional to weight of a food item to be thawed is determined, and as a result a final optimum thawing time is determined by multiplying the weight factor and the thawing time together.

Abstract: A microwave oven includes a control circuit provided for properly heating food on the basis of detection by an alcohol sensor. Upon depression of a beverage key of an operation panel, the control circuit detects change rates of signals generated by the alcohol sensor before the heating operation and during the heating operation. When the change rates exceed respective reference values, beverage to be heated is determined to be Japanese sake. When the determination before the heating operation does not coincide with that during the heating operation, the control circuit determines which the beverage is, the sake or the milk or the other type of beverage, on the basis of the determination both before and during the heating operation, setting a driving period of time of a magnetron accordingly.

Abstract: A method of preventing a no-load operation of a microwave oven. If a resistance of a gas sensor is greater than a first predetermined value, a cooking operation is normally performed. An initial signal value sensed by a temperature sensor is compared with a second predetermined value if the resistance of the gas sensor is smaller than or equal to the first predetermined value. If the initial signal value is greater than the second predetermined value, the initial signal value is compared with a signal value sensed by the temperature sensor after the lapse of a predetermined time period. If the initial signal value is greater than the sensed signal value, the cooking operation is normally performed. If the initial signal value is smaller than or equal to the sensed signal value, the present operation is discriminated as the no-load operation and the cooking operation is then stopped.

Abstract: An apparatus for and a method of automatically heating foods in a microwave oven, capable of heating foods at an optimum state even when foods are to be continuously heated, by determining an ambient temperature from a variation in temperature of air introduced in a heating chamber through an air inlet port, determining a temperature increment in a heating chamber of the microwave oven and an amount of food, based on the determined ambient temperature, determining a primary heating time and an additional heating time, based on the determined temperature increment, and then determining an additional heating time, based on the determined food amount. As a result, it is possible to achieve an improvement in cooking performance. In addition, over-heating of the good is avoided, thereby enabling a reduction in electric power consumption and a reduction in cooking time.

Abstract: A microwave oven has only a microwave sensor or both microwave sensor and temperature sensor. The microwave sensor has a wave absorber to generate heat through absorption of microwave energy and a thermistor to detect temperature of this wave absorber. The temperature sensor has a thermistor to detect the ambient temperature around the wave absorber. A controller determines a value of microwave power on the basis of the output of the microwave sensor or each output of the microwave sensor and temperature sensor. The microwave oven can accurately detect microwave power without being influenced by variation of ambient temperature around the microwave sensor.

Abstract: A heating apparatus such as microwave ovens includes a heater heating food contained in a cooking chamber and a temperature sensor sensing the temperature in the cooking chamber. An initial temperature is detected at an initial stage of the cooking on the basis of the temperature sensed by the temperature sensor. An intermediate temperature is further detected a predetermined time period after the start of the cooking. Based on the difference between the detected initial and intermediate temperatures, a suitable cooking period of time is determined.

Abstract: A microwave oven includes a heating chamber, a plurality of cooking utensils detachably disposed in the heating chamber selectively in accordance with the cooking contents, a plurality of heat sources heating food placed on or contained in the cooking utensil and including a magnetron, an oven heater and a grill heater, optical sensors determining the cooking utensil disposed in the heating chamber, and a microcomputer. The cooking utensils include a glass dish, thawing gridiron, pot, upper and lower top plates, one-legged top plate, and gridiron. A microwave cooking mode is selected when the determination of the optical sensors indicates that neither upper nor lower top plate is present in the heating chamber. A heater cooking mode is selected when either upper or top plate is present. When the heater cooking mode is selected on the basis of presence of the upper top plate, either an oven mode or a grill mode is selected depending upon presence or absence of the gridiron.

Abstract: A cooking appliance, which automatically toasts bread, and has a heater, a gas sensor, and a thermistor. The gas sensor detects moisture which comes from the bread. The thermistor detects the temperature within the cooking cabinet. A microcomputer measures gas driven from bread during toasting to determine whether the bread was initially frozen or not. The time of gas sensor reading is determined based on an initial temperature within the cooking cabinet so that the decision will not be made inaccurately due to repeated use of the cooking appliance.