Abstract: Ginkgo leaves contain many beneficial chemicals which can be transferred into a preparation of tea. However, the leaves contain 2-hexenal, a chemical which is toxic and has an unpleasant taste. Therefore, removal of the 2-hexenal is an essential step for the tea production. This removal is accomplished in this invention by a microwave apparatus, which has the advantage of a rapid rate of treatment at great energy efficiency. Therefore, this invention provides an effective means for large scale ginkgo leaf tea production.

Abstract: A microwave oven having an improved air outlet and humidity sensor mounting structure includes a body partitioned in its interior into a cooking cavity and a machine room, and a cooling fan installed in the machine room which draws atmospheric air into the cooking cavity while cooling a variety of elements installed in the machine room. In the microwave oven, an air outlet unit discharges air from the cooking cavity, and the humidity sensor senses a cooking atmosphere of the cooking cavity. This microwave oven further comprises a control unit which determines the conditions of food in response to automatically or manually inputted information, and controls the rpm of the cooling fan in response to the determined conditions of the food so as to improve the sensing performance of the humidity sensor.

Abstract: A control or regulating device of a stove influences (activates, deactivates, controls, regulates) the heat energy of at least one cooking zone of the stove in dependence upon cooking steam. The control device or a sensor device of the control device can be installed at least partly in a fume hood of the stove.

Abstract: A microwave oven includes a humidity sensor, a main-outlet and a sub-outlet formed at opposite sidewalls of a cooking cavity such that the cooking cavity communicates with the atmosphere through the main-outlet and the sub-outlet. The sub-outlet is installed in a machine room adjacent an air inlet side of a cooling fan. The humidity sensor is installed in the machine room at a position adjacent to the sub-outlet and senses the humidity of air inside the cooking cavity by sensing the humidity of a part of the air discharged from the cooking cavity through the sub-outlet. The surface of the humidity sensor is less likely to be easily contaminated by the air exhausted from the cooking cavity, moisture deposited on the surface of the humidity sensor 60 is quickly evaporated so that the humidity sensor performs its desired operation even when the microwave oven sequentially performs several cooking processes.

Abstract: A process and apparatus for removing moisture from a material, without spoiling the processed product, through the implementation of microwave irradiation heating, drying, dehydration, curing, disinfection, pasteurization, sterilization or vaporization or any combination thereof. The process and apparatus provide for a controlled processing of planar material, a combination of materials organic or inorganic, in natural or processed form, in sheet leaf, granular, prepared or transportable planar form.

Abstract: A microwave oven, and method of controlling the same, including a magnetron generating high-frequency waves and a sensor detecting the environmental state of air in a cooking cavity. During a first cooking time, outputs of the sensor are sampled at predetermined periods, with the duration of first cooking period being calculated, by a controller, based on the result of the sampling. Thereafter, a second cooking time is calculated, by the controller, based on the first cooking time and the kind of food. A cooking operation is then completed for the second cooking time.

Abstract: The present invention provides a high frequency heating apparatus equipped with an oven hood fan, including a heating chamber for entering/deriving an article to be heated into/from the heating chamber; an electric power supplying apparatus for radiating electromagnetic waves into the heating chamber; cooling means for cooling the electric power supplying apparatus; another heat-cooking apparatus provided with heating means operated by gas and electric power, which is installed under an appliance main body; and ventilating means for sucking hot air from an air intake port, which is generated from the another heat-cooking apparatus, and for exhausting the sucked hot air. In the apparatus, wind which cools a heat generating unit of the electric power supplying apparatus by the cooling means is joined onto an air intake path of the ventilating means.

Abstract: A microwave oven includes a magnetron to generate microwaves and a cooking chamber to contain food to be cooked using the generated microwaves. The microwave oven further includes a humidity detector to detect moisture formed from the food being cooked. The humidity detector is provided at air outlets of the cooking chamber, and includes first and second electrodes formed on a board to be spaced apart from each other at a predetermined interval to form a gap therebetween. The control unit of the microwave oven controls the cooking operation of the microwave oven according to the output of the humidity detector.

Abstract: End of cycle detector and method for a microwave clothes dryer. The temperature of fabric in the dryer is monitored, an increase in the monitored temperature is detected when substantially all moisture has been removed from the fabric, and operation of the dryer is controlled in response to the increase in temperature.

Abstract: A grain containment vessel equipped with one or more antennas and a vapor extraction system is disclosed. An electromagnetic heating pattern is established throughout the grain volume elevating the bulk temperature, while an air flow is applied throughout the grain volume. The electromagnetic energy desorbs the water and increases the vapor pressure and the air flow carries the heat and water from the containment vessel. A controlled amount of electromagnetic energy is introduced into the grain volume to reduce or eliminate fungus infestation and increase insect mortality.

Abstract: A toploading weighing instrumentality which determines loss on drying by a cylindrical microwave. The cylindrical cavity of the microwave includes a power supply, a magnetron, a power module operatively coupled between said power supply and said magnetron for driving said magnetron, a wave guide communicating with the magnetron and with a microwave containment chamber for delivering energy thereto, at least one microwave energy sensor for sensing microwave energy or magnetic and/or electric field strength within the chamber for controlling, inter alia, the loss on drying process of the sample being assayed and determining when the drying process is complete. A precision electronic balance is operatively disposed within the microwave chamber for allowing a specimen being assayed to be weighed. In addition, a ventilation chamber is provided for venting moisture from the microwave chamber.

Abstract: An object of a high-frequency thawing apparatus is to uniformly thaw an entirety of an article with high efficiency and high-speed, particularly an article having a relatively large thickness. The apparatus is so constructed that a high-frequency power from a high-frequency generating circuit is supplied to a pair of opposing electrodes by way of an impedance matching circuit including a transformer to thaw an article (F) which is carried in between the opposing electrode pair by dielectric heating. The impedance matching circuit includes an electrostatic capacitor section (C) and an inductance section (L). A conductor each constituting the inductance section (L) has such a length that the downstream-located conductor with respect to the transport direction of a conveyor is longer than the upstream-located conductor.

Abstract: A cooling device for halogen lamps in microwave ovens is disclosed. In the cooling device, two halogen lamps, installed on the top wall of the cavity, radiate light waves into a cavity. A cooling fan assembly, provided at a position around the halogen lamps, generates a cooling air current for the lamps. An air guide duct guides the cooling air current so as to allow the air current to flow from the cooling fan assembly into the atmosphere while cooling the lamps. An exhaust fan is provided within the air outlet port of the air guide duct. The exhaust fan increases the flowing rate of the air current at the air outlet port, which is bent at a right angle. Due to the exhaust fan, the cooling device of this invention more effectively cools the halogen lamps and allows the cooling air current to be more smoothly discharged from the duct into the atmosphere regardless of the bent shape of the air outlet port.

Abstract: The method is for the control of an electrical oven and includes taking into account the temperature and/or the humidity level of the air measured by sensors in the interior of a cavity of an oven in which food to be heated and/or cooked is placed. The instantaneous value of the supplied power of the magnetron of the oven and the duration of a heating cycle are controlled, such as by fuzzy logic.

Abstract: A wet prevention apparatus for a sensor of a microwave oven is disclosed, which prevents wet from occurring in a sensor for use in a microwave oven without a separate driving gear. In a microwave oven including a cooking chamber, and a machine chamber isolated from the cooking chamber by an isolation wall having a sensor hall, wherein a sensor case having a sensor therein and a fan are mounted in the machine chamber, the wet prevention apparatus for a sensor of the microwave oven includes an air receiving member for moving by air flow which occurs when driving the fan, and a blocking member linked to the operation of the air receiving member, for selectively blocking the sensor hole.

Abstract: The stack height and moisture content of baked goods produced continuously in a multi-zone oven, such as a gas-fired band oven, is controlled and adjusted using microwave energy. Color development, flavor development, texture, and appearance of the baked products are not adversely affected by the replacement of a substantial amount of the non-microwave energy input with microwave energy. The stack height and moisture content of the baked product may be controlled or adjusted with the microwave energy to be within predetermined ranges or specifications independently of each other. Upon detection of product which is not within specifications, the microwave energy may be used to rapidly adjust stack height and/or moisture content so that they quickly return to their predetermined acceptable levels thereby substantially reducing product waste or recycling. The stack height of the baked pieces is controlled and adjusted using microwave energy early in the baking process.

Abstract: Method and microwave oven for controlled boiling of a foodpiece. The foodpiece is heated rapidly into reliable boiling by a supply of maximum microwave power, thereafter a desirable degree of boiling (H.sub.eb) is carried out during a predetermined boiling time (T.sub.b) while controlling the supplied microwave power level dependent on feed-back information (HUM) from a sensor. The boiling procedure is carried out fully automatically with consequently increased user security, decreased energy consumption and improved boiling quality.

Abstract: A polarity discriminating method and signal processing circuit for a vapor sensor in a microwave oven is disclosed. The control section operates a fan motor so as to discriminate the polarity of a detecting signal supplied from the vapor sensor, which is varied with the wind produced by the fan motor. After the control section initializes variables of counters, the control section compares the magnitude of the signal-processed detecting signal supplied from the detecting signal processing circuit section with the magnitude of a reference detecting signal in a specified range on the phase coordinate axis. Meanwhile, the control section discriminates whether the slope of the curve of the signal-processed detecting signal is positive or negative, thereby discriminating whether the vapor sensor operates in a positive polarity mode or negative polarity mode.

Abstract: After the initial temperature T0 of a heating chamber is sensed (S34), heating by microwaves is conducted until the sensor output of a humidity sensor exhibits a prescribed humidity change amount of 1.0 V (S35-S39). Then, an additional time period is operated based on initial temperature T0 and a time period passed for the elevation of 1.0 V (S40-S42, S50). Heating by microwaves is conducted for the additional time period (S43, S51), and then heating by a heater is conducted. As a result, the moisture included in the food is evaporated and finished crisp. In other words frozen precooked food may be thawed and cooked into a tasty state.

Abstract: An automatic control system for regulating the cooking process of a food product where it reaches the desired result respective of the initial temperature of the food product, its moisture content or quality. The invention solves the problem by using the characteristic breakpoints (2,3,4,5) that, whereby the adding of heat, occurs on one or two temperature curves (12,13) obtained at different measuring points, when the temperature again rises after the temperature drop of the heat transportation of medium after the insertion of the food product with a lower temperature than the heat transportation medium or when water transites from solid to liquid form (2,3) and from liquid form to steam (4,5).

Abstract: An apparatus and method for detecting the presence or absence of a container cover and for determining how much food is present in a microwave oven. The apparatus includes a sensor for sensing the state of an exhaust from the heating chamber in the microwave oven, and a sensor output processor for processing a signal from the sensor, calculating cooking information according to the signal, and identifying the presence or absence of a container cover and determining how much food is present by utilizing the cooking information and inputted cooking time information to provide a control signal for controlling a heating time of said heating chamber.

Abstract: A method for automatically controlling cooking by using a vapor sensor in a microwave oven is disclosed. The method for automatically controlling cooking air-cools the cavity for a predetermined time by means of the driving of a fan motor during the automatic cooking operation, and respectively compares magnitude and phase of a signal-processed detecting signal supplied from a detecting signal processing circuit section with magnitude of reference detecting signal and values of reference phases in order to discriminate the polarity of the signal-processed detecting signal. Also, the executing time of the air-cooling operation related to a cooking chamber, which is additionally provided in response to the discriminated polarity, is discriminately adjusted.

Abstract: A microwave oven includes a microwave oven chamber in which food is cooked, an input unit for selecting modes of operation and other options, a control unit for driving the microwave oven by a driving signal input from the input unit, an oscillator for generating microwave in the chamber according to the driving signal from the control unit, a sensor unit for detecting a level of vapor generated from the food being cooked and outputting a detection voltage signal corresponding to the detection, and an indicator unit for continuously indicating the cooking state of the food according to the detection voltage signal as the cooking state progresses.

Abstract: A heating apparatus such as a microwave oven includes a magnetron supplying microwaves into a heating chamber so that food accommodated in it is heated and a microcomputer-based control circuit. The control circuit discriminates the food among three conditions, that is, a first condition in which the food is not wrapped in a wrap film, a second condition in which the food is wrapped in a wrap film, and a third condition belonging neither to the first nor to the second condition. Based on the results of discrimination, the control circuit calculates a remaining heating time.

Abstract: An improved sensor malfunction prevention apparatus for a microwave oven capable of preventing a malfunction and an infrared ray sensor from being polluted by dusts, food debris or the like from a cooking chamber, which includes a cooling fan; an air duct for guiding cooling air introduced into the interior of the microwave oven in cooperation with the cooling fan; a sensor support bracket disposed at a predetermined inner portion of the air duct; a sensor disposed at a predetermined potion of the sensor support bracket; a protective cover support disposed at the upper portion of the sensor support bracket for defining air openings between the protective cover and the sensor support bracket; and a protective cover fixed to the protective cover support.

Abstract: A highly reliable, accurate humidity measuring device which detects differences in humidity between datum air and measuring air as a time or a phase difference in the propagation velocity of sonic waves, using sonic wave generating and receiving means, and processes this difference using circuitry to provide the humidity condition in the air being tested. Also an oven or heating cooker is disclosed equipped with the humidity measuring device so that it can detect the cooking condition of food by measuring temperature changes due to the steam generated from the food and then using the humidity measuring device to determine when to shut off the heat source of the oven.

Abstract: A sensor based automated cooking apparatus is provided. A humidity sensor measures the moisture content within a cooking cavity. An output of the sensor is provided to a digital filter to remove noise therefrom before being passed to a feature extractor which performs a data compression step and extracts salient features relating to the shape of the humidity versus time characteristic. The parameters are analyzed by a neural network to estimate a degree of doneness of the food. A controller uses the degree of doneness to estimate the remaining cooking time and appropriate power level. The cooking apparatus then operates in an open loop mode for the remainder of the cooking time using the appropriate power level.

Abstract: A method for controlling cooking by using a vapor sensor in a microwave oven measures and records a magnitude of a detecting signal from the vapor sensor in response to water vapor generated from food subjected to heating. When the temperature of food is judged to exceed a predetermined temperature on the basis of the measured magnitude of the detecting signal, a control section compares the average magnitudes of the detecting signals from the vapor sensor with reference magnitudes to judge whether the temperature of food subjected to heating corresponds to a reasonable temperature. If the temperature of food is lower than the reasonable temperature, the food is additionally heated for a preset time. Thus, the outputs of the vapor sensor varied according to the sizes of containers filled with food are selectively controlled to prevent the malfunction of the vapor sensor caused by the different sizes of containers.

Abstract: Disclosed is a method capable of controlling read-time of a humidity sensor of a microwave oven so as to void interference by other parts in the microwave oven or exterior apparatuses, and thereby sensing an accurate humidity value in the microwave oven. In the method, one period of a frequency of an electric power is divided into a first section and a second section according to an outer interrupt signal. The humidities are sensed by predetermined times respectively in the first section and the second section, and then a noise count is increased in a corresponding section when a difference between a maximum value and a minimum value in each section is larger than a predetermined reference value. The obtained noise counts are compared, and then one section having less noise count is determined as a humidity sensing read time section.

Abstract: Disclosed is a method capable of controlling read-time of a humidity sensor of a microwave oven so as to avoid interference by other parts in the microwave oven or exterior apparatuses, and thereby sensing an accurate humidity value in the microwave oven. In the method, the humidity sensing read time is determined in a rest section at which the oscillation of microwave by the magnetron is instantly interrupted, and thereby a safe and reliable humidity sensing value can be sensed.

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: In a microwave oven, a procedure for cooking or heating food is controlled by means of one or more humidity sensors (11) which sense the humidity emission from the food or dish. The control is based on the sensing of relative humidity variations and require access to an initial humidity value or reference value, which is established through a calculation process eliminating the effect of residual humidity remaining in the oven while saving time when starting the cooking or heating procedure.

Abstract: An improved heating time control apparatus and method thereof for a microwave oven capable of advantageously computing an optimum cooking time without controlling the amount of food to be cooked. The invention includes: a sensor for detecting a predetermined physical, i.e.

Abstract: An oven, particularly with an apparatus for pyrolytic self cleaning, includes an oven wall having an exhaust opening formed therein through which exhaust produced during oven operation can flow out to the outside. A throttle automatically adjusts an exhaust flow cross section of the exhaust opening or of a flow conduit adjoining the exhaust opening.

Abstract: A method of automatically thawing a food in a microwave oven, is disclosed. The method of optimally thawing the food and preventing a phenomenon that the food is partially boiled. The method includes by primarily heating the food for a predetermined time where the food is large in amount, turning the primarily heated food and then additionally heating the turned food, while eliminating the step of turning the food where the food is small in amount.

Abstract: A smoke and vapour detector for microwave ovens comprises a light transmitter (12) and two light receivers (13, 14) arranged in a housing (11) through which air from the microwave chamber flows during a heating procedure. One receiver (13) is designed to receive direct light from the transmitter (12), and the other receiver (14) is designed to receive indirect or scattered light from the interior of the housing (11). The signals from the receivers are differentiated and subtracted from one another in order to generate a difference signal indicating the presence of smoke or water vapour in the chamber air.

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 thawing a food in a microwave oven, capable of achieving an optimum thawing of the food by temporarily stopping the heating of the food for a predetermined time after completion of an initial heating of the food, determining whether an additional heating of the food should be executed, on the basis of a variation of an output signal generated from a gas sensor, during the temporary stop interval, and calculating a time for the additional heating, during the temporary stop interval.

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: Apparatus and method for removing the influence of microwave noise, without any shielding parts, thus increasing the reliability of detected humidity information. According to the invention, the cumulative difference of humidity values sensed by a humidity sensor is calculated for each half period of a commercial alternating current frequency, oscillating and non-oscillating terms of a magnetron are determined by comparing the calculated cumulative differences with each other, and the humidity-sensed values obtained during the determined non-oscillating terms of the magnetron are used as humidity information for automatic cooking control. In order to even further remove the influence of the microwave noise, the humidity sensor may include capacitors for bypassing the microwave noise introduced into the sensor.

Abstract: An automatic thawing device of a microwave oven and a method for control thereof. A turntable is rotatably placed in a cooking chamber. A gas sensor is placed about an exhaust port of the oven and senses amount of gas or vapor exhausted from the cooking chamber through the exhaust port during a thawing operation, and outputs a gas amount signal to a microprocessor. The microprocessor calculates a thawing time by operation of the output signal of the gas sensor an outputting a thawing control signal for driving the microwave oven. An output drive unit controls output level of electromagnetic wave of high frequency of a magnetron in accordance with the thawing control signal of the microprocessor. The magnetron generates the electromagnetic wave of high frequency in accordance with output signal of the drive unit for the thawing time. A power source supplies an electric power to the thawing device in accordance with the thawing control signal of the microprocessor.

Abstract: A heating apparatus comprises a microprocessor and an alcohol sensor detecting the amount of the alcohol gas generated from a food item to be cooked in a heating cavity of the heating apparatus. The heating operation of the apparatus and a cleaning operation to expel the air in the heating cavity are controlled by the microprocessor. The cleaning operation is performed after the heating operation in accordance with the amount of the alcohol gas detected by the alcohol sensor.

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: In accordance with the invention an arrangement for controlling the heating power for a vessel (10) which can be heated by a cook-top (11), for example a light cook-top, by means of a sensor-controlled electronic device (19) can perform more functions in thatat least one (cooking-substance) sensor (18) is associated with the vessel (10) to detect the temperature of the foodstuffs (17, 15),the vessel (10) only communicates with the ambient air via a measurement tube (13) in which a (steam) sensor (20) and, optionally, a steam sensor (21) are arranged to detect the steam point of a liquid (14) present in the vessel, andall the sensors (18, 20, 21) are connected to the electronic device (19) and can be combined with one another via the electronic device.

Abstract: Method and apparatus for automatic cooking in a microwave oven capable of executing the automatic cooking in an optimal state by detecting an outflow air temperature and a weight of food at an initial stage, calculating an outflow air temperature difference after executing a cooking operation for a predetermined time, calculating an additional value by giving a fuzzy membership function to the outflow air temperature difference and the weight of food, calculating a first stage heating time by executing an operation process according to a fuzzy rule, calculating second to fifth stage heating times by multiplying the first stage heating time by predetermined values, respectively, and executing a cooking operation for the calculated stage heating times.

Abstract: A heating cooker includes a cooking chamber having a heater for heating food, a gas sensor for detecting the quantity of vapor evaporating from the food heated in the cooking chamber, a temperature sensor for detecting a temperature in the cooking chamber, and a controller for determined the kind of the food according to the quantity of vapor detected by the gas sensor, and for controlling the heating temperature and heating time of the heater according to the kind of food which has been 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: When heat cooking of food placed in a heating chamber of a microwave oven is started, smell given out of the food is detected and a cooking sequence program suitable for the kind of the food is automatically selected based on the information of the detected smell. Heat cooking of the food is carried out thereafter following the selected cooking sequence program. In parallel with this heat cooking, the smell given out of the food is detected to detect fire of the food based on the information of the detected smell. When fire of the food is detected, heating of the food is immediately interrupted, thereby preventing damage to the oven which is caused by abnormally high temperature in the heating chamber, while preventing further browning of the food.

Abstract: An automatic cooking method for cooking food wherein one of a timed or automatic cooking mode is selected prior starting the heating of the food upon depressing a cooking start key. The quantity or concentration of gas (e.g. carbon dioxide) or smoke emitted from the food every sampling time of a certain period is determined, and counting the time T1 taken for the quantity or concentration of gas or smoke to vary from a predetermined minimum value to a predetermined maximum value is also determined. The cooking is carried out to further heating the food for a time T2 calculated by multiplying the counted heating time T1 by a coefficient predetermined depending on the food.

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.