Abstract: A cooking device with one cooking or heating chamber in which food may be heated by either one or both of high-frequency heating means and the resistance heating means. The high-frequency or microwave energy is radiated into the heating chamber from the top while the air heated to high temperatures by the resistance heating means disposed within a rear chamber defined back of the rear wall of the heating chamber is circulated therethrough by a circulation fan. Food charges are placed on a receptacle which in turn is placed on a turntable, whereby the food charges may be uniformly heated. The simultaneous use of both the high frequency heating means and the resistance heating means may enable a more wide variety of food to be cooked by a more wide variety of methods.

Abstract: A high voltage switch for use in a microwave oven is disclosed which switches a high voltage by an external electric signal. The high voltage switch includes a slider guide chamber of insulative material between a contact making and breaking chamber for switching the high voltage and an electromagnet device to which a low voltage is applied and which serves as a power source for making and breaking the contact, so that the high voltage section is isolated from the low voltage section. An insulative slider extends through the slider guide chamber, and an armature which is directly driven by the electromagnet device and a conducting movable member having a movable contact mounted in the contact making and breaking chamber are linked by the insulative slider. The armature and the conducting movable member are pivotably mounted at their ends so that the drive operation by the electromagnet device is amplified to break the contact. As a result, a small electromagnet device of the A.C.

Abstract: A high requency heating apparatus including a door assembly having a high frequency energy shielding member and a plurality of glass plate members disposed in front and on the outer side of the shielding member. The distances between the shielding member and plurality of glass plate members are such that a composite-impedance Z.sub.T made up of the impedance of the shielding member, the impedance of the glass plate members and the impedance of the space around the heating apparatus becomes approximately equal to or smaller than the composite impedance Z.sub.s made up of the impedance of the shielding member and the impedance of the external space in the absence of the glass plate member for reducing microwave leakage at the front portion of the door assembly.

Abstract: A microwave oven which is provided with an electric heating arrangement for surface browning of an object to be heated which includes a heater portion having a heater surrounded by a sheath and a power supplying base portion enclosed in a metallic cover and having power supplying electrodes for the heater portion, and power feeding section having choke structure for preventing leakage of high frequency waves which is provided in one of the walls defining a heating cavity so as to receive the power supplying base portion in an opening formed in the choke structure, while the sheath is so connected to the metallic cover as to establish good electrical conduction therebetween, so that sealing of high frequency waves is achieved between the heater and choke structure.

Abstract: A microwave oven is equipped with a rotary table driven by magnetic coupling. The microwave oven has a heating chamber in which at least its bottom wall or base plate is made of a non-magnetic metallic material, while its other walls are formed of metallic material other than non-magnetic metallic material, for reduction of the cost of the microwave oven. The junctions between the wall of non-magnetic metallic material and the walls of metallic material other than non-magnetic metallic material are coated with coating film to improve corrosion resistance. Furthermore, the heating chamber together with the rotary table is so arranged as to facilitate insertion and withdrawal of a container of food material into and from the heating chamber to provide a microwave oven which is clean and convenient to use.

Abstract: A microwave oven equipped with a rotary table for placing food material to be cooked thereon in which the rotational center of the rotary table within the heating chamber is offset toward the rear wall of the heating chamber from the central portion of the distance between the inner surface of the door and the rear wall of the heating chamber, that distance being larger than the inner width of the heating cavity for preventing the danger of electric wave leakage resulting from breakage of a shielding plate and its reinforcement in the oven door due to contact of the food material or a spit carrying the food material with such reinforcement and resultant spark discharge.

Abstract: A microwave oven including a rotary table or turn table disposed on the bottom surface of a heating cavity and a rotary member associated with a driving motor through a driving mechanism and disposed adjacent to the rotary table and the bottom wall of the heating cavity for rotating the rotary table through magnetic coupling means. Should the rotary table be prevented from being rotated or locked for some reason, the magnetic coupling is released, so that damage to the driving motor and the like are advantageously prevented.

Abstract: A microwave oven is provided with an automatic timer-controlled output power controlling system, the microwave oven comprisingA microwave generator capable of generating a larger output power and a smaller output power,A first timer means which sets a first time period of generating said larger output power,A second timer means which sets a second time period of generating said smaller output power andAn output controlling means which controls said microwave generator so as to generates the larger output power for said first time period and subsequently the smaller output power for said second time period.

Abstract: A microwave oven equipped with a rotary table or turntable includes a heating chamber whose rear wall is formed into a concave shape of semi-circular cross section approximately concentric with a rotational center of the rotary table to eliminate any idle space at corner portions in the heating chamber for providing an economical microwave oven of compact size, and also to prevent the rotary table from being locked by a large object to be heated which may be caught by the corner portions during rotation, with the simultaneous elimination of damage to an observation window due to spark discharge arising from a metallic material included in the object, and with the further improvement of uniform heating within the heating chamber.

Abstract: A microwave oven providing the combination of dielectric heating by the use of microwaves and resistive heating for scorching the surface of a food. An isolation chamber for accommodating an article to be heated by a resistive heater is formed adjacent to the resistive heater provided in a heating cavity. When heating by the resistive heater is desired, the article to be heated is accommodated in the isolation chamber so that it is heated either both by dielectric heating and resistive heating or solely by resistive heating for scorching in an effective manner and at the same time minimizing the contamination of the heating cavity. In this manner, the application of the microwave oven may be widened and the usefulness of the microwave is enhanced.

Abstract: A structure of a microwave oven door screen which facilitates the observation of the inside of a heating cavity and enhances the safety against the electromagnetic wave leakage and durability. A door screen of this type generally comprises a pair of transparent plates and an electromagnetic wave shielding material interposed therebetween. The present door screen uses a punched metal plate as the electromagnetic shielding material made of aluminum having a thickness of 0.1 to 0.35 mm, an aperture diameter of 1.2 mm or less and a ratio of the aperture diameter to a center-to-center distance of an aperture of 0.67 to 0.85, these parameters being chosen such that an aperture rate of more than 40% is assured and the electromagnetic wave leakage through the door screen is effectively prevented (to meet the Regulations of U.S. Department of Health, Education, and Welfare) and a strain due to continuous mechanical treatment of the punched metal plate is minimized.

Abstract: A microwave oven comprises a timer for setting a cooking time period, a cooking menu selector with a scale indicating an optimum heating time period for each type of food and quantity thereof and a high frequency output selection switch linked to the cooking menu selector or operated manually. By operating the cooking menu selector to select a corresponding scale for the food to be cooked and setting the timer to a quantity of the food marked on the selected scale, an optimum heating time period may be set, and at the same time the high frequency output selection switch is actuated in a linked relation with the cooking menu selector or manually to select a high frequency output which is optimum to the type of food to be cooked. An output indicator for indicating the selection of the high frequency output is also provided in linked relation to the high frequency output selection switch.

Abstract: A microwave oven having an improved electric field distribution to allow uniform heating of an article to be heated is disclosed. High frequency exciting means is positioned at the center, both depthwise and lengthwise, of a heating chamber of substantially parallelepiped structure, and the shapes and construction of the reflecting plate, stirrer vane, mount for partition and heating cavity are improved to allow uniform electric field distribution and improvement in cooking performance.

Abstract: Microwave oven is provided with an improved door screen which allows an undisturbed clean observation of the heating chamber and at the same time assures safety and durability in use. The door screen comprises an electromagnetic wave shielding means made of a metal mesh interposed between a pair of transparent plates. The metal mesh is constituted by electrically conductive woven wires having a predetermined diameter with the space between the wires also being numerically predetermined.

Abstract: A microwave oven whose door screen is constructed by interposing an electromagnetic wave shielding body of a metallic plate having a plurality of through-holes formed therein or a wire screen, between a tempered glass plate and a transparent resin plate, with the tempered glass plate being placed on the side of a heating cavity while the transparent resin plate being placed outwardly, a peripheral section of the shielding body extending to electrically connect with a metal plate which, essentially, electrically connects the heating cavity with the door body, whereby observation of food in the heating cavity during cooking can be facilitated while the safety from electromagnetic wave leakage is assured.

Abstract: A microwave oven has an oven-defining housing structure having an electric lamp used to illuminate the interior of the oven-defining housing structure, that is, a heating chamber. The oven-defining housing structure has a control panel at the front thereof, which control panel includes one or more signaling windows or indicators to be illuminated, for example, one signaling window representing, when illuminated, that the high frequency wave generator is in position to generate a low radiating energy into the heating chamber and the other signaling window representing, when illuminated, that the high frequency wave generator is being operated. These signaling windows are respectively illuminated by portions of rays of light emitted by the oven lamp by means of light transmitters. Respective shutter mechanisms are provided for controlling passage of the light rays from the oven lamp towards the signaling windows so that the latter can be illuminated at required times.

Abstract: A microwave oven with an improved electric field distribution in the oven is provided. By properly establishing the position of a high frequency oscillator when it is directly affixed to a heating cavity or the position of a feeding opening when the feed through a wave guide is employed, with respect to the dimension of the heating cavity, the electric field distribution is improved and the efficiency is enhanced.