Matsushita Electric Industrial Co., Ltd.

Kimiaki Yamaguchi

Koji Yoshino

Shinichi Sakai

Takashi Kashimoto

Isao Kasai

Takashi Niwa

Masahiro Nitta

Kazuyuki Inoue

Yoshihiro Toda

Satomi Moriyama

Susumu Murakami

Haruo Suenaga

Kazuho Sakamoto

Naoyoshi Maehara

Takahiro Matsumoto

Mitsuo Akiyoshi

Ryuji Suzuki

Kazumi Hirai

Shunichi Nagamoto

Haruo Matsushima

Masaaki Sano

Toyotsugu Hatagawa

Tatsuji Isono

Masato Yota

Masato Youta

Akinori Otsuka

Teruo Hirose

High-frequency heating apparatus with copper for grounding layer

A high frequency heating apparatus and an electromagnetic wave detector for use in the high frequency heating apparatus, are so arranged to estimate the cooking or thawing state of a food article placed in a heating chamber through detection of microwaves within the heating chamber. By devising a position of an antenna and a method of processing signals of the microwaves as detected, stably and reliable microwave detection becomes possible.

High frequency heating apparatus and electromagnetic wave detector for

A heating apparatus such as a microwave oven in which thermal energy of high-temperature vapor generated by heating an object is detected by a pyroelectric element and a resulting detection signal is used to control (stop) a heat source such as a microwave source, etc. Among AC voltages generated by the pyroelectric element due to heat exchange of the pyroelectric element, a voltage of a polarity generated at the time of heat discharge (temperature decrease) of the pyroelectric element is selected through a circuit means. A voltage generated by heat exchange between air moving slowly in a heating chamber and the pyroelectric element caused by the rotation of a turntable or the like is eliminated by another circuit means. A control section controls the operation of the heat source by deciding an output signal of the pyroelectric element by comparing it with a detection level determined in accordance with a noise level for a predetermined length of time after the start of the heating operation. Erroneous detection is thus prevented which otherwise might be caused by a noise voltage generated in the pyroelectric element by the thermal energy of a hot air staying in the heating chamber after the energization of the heat source or second heat source.

Heating apparatus

A heating and cooking apparatus has a detection sensor for sensing the state of heating so as to automatically control the heating operation. A partition is disposed so as to be opened to the inside of an auxiliary passage which has an inlet located at a position in the vicinity of the circumference of an impeller of a cooling fan for cooling a magnetron provided on the back side of a heating chamber and through which steam from the heating chamber is discharged to the outside. Air supplied by the fan is blown off into the auxiliary passage so as to generate a venturi action, thus promoting the flow of steam in the auxiliary passage. The detection sensor is disposed in the auxiliary passage at a position in the vicinity of a region where air is blown off so as to accurately sense the state of steam generated from a material to be heated.

Automatic heating apparatus having a system for sensing the temperature

A pyroelectric sensing apparatus is provided with an A/D convertor 29, whose digital output is examined whether continuation time period of the output from the pyroelectric element is longer than a predetermined reference time period such as 500 m sec; thereby mal-operation due to noise output from the pyroelectric element generated by mechanical shock (door close) or electric shock (pulling out a plug of other apparatus) is eliminated.

Pyroelectric sensing apparatus substantially independent of noise output

A stationary induction apparatus for supplying and receiving high frequency power of several tens KHz, wherein a partition wall made of a non-magnetic metallic foil in a thickness less than 1/10 the depth of penetration in the using freqency for electromagnetic induction is provided so as to separate the supply side (primary side) from the receiver side (secondary side), so that the stationary induction apparatus is not hurt in its function as an induction apparatus, but can electromagnetically shield the primary side from the secondary side, and the secondary side of the boosting transformer of the magnetron is able to be placed within the shield casing, thus realizing a light, compact and inexpensive microwave generating device for use in an electronic oven.

Transformer having shielding wall for driving a magnetron

A cooking heating apparatus has a vapor sensor for sensing the state of heating of food in a heating chamber, thus performing automatic control of the heating operation. An auxiliary exhaust opening for allowing vapor from the heated food to be introduced to the vapor sensor is formed in a region where the flow of the vapor is not influenced by a main flow of air supplied into the heating chamber and flowing towards a main exhaust opening. The vapor sensor is disposed so as to be exposed to the vapor introduced through the auxiliary exhaust opening. The condition of the vapor is therefore sensed quickly without being influenced by the main flow of air.

Oven with an exhaust opening for collecting vapors to control material

A high-frequency heating apparatus comprises a semiconductor power converter which is supplied with electric power from a commercial power supply, a radio wave radiation section which is energized by the semiconductor power converter, a control section which controls the operation of a semiconductor element of the semiconductor power converter, and a start control section which controls the operation of the control section at the start time of the high-frequency heating apparatus. The start control section controls the operation of the control section so that the radio wave output power from the radio wave radiation section at the start time of the high-frequency heating apparatus becomes greater than that in the steady operation state thereof, whereby optimization of the performance and price of the heating apparatus can be realized.

High-frequency heating apparatus having start control device for

A high frequency heating device includes a high frequency oscillator, a heating chamber for accommodating an object to be heated, and a cylindrical wave guide for coupling the high frequency oscillator to the heating chamber. The output antenna for the high frequency oscillator is disposed at an input end portion of the cylindrical wave guide and along the center axis of the wave guide. The heating chamber has a wall which is coupled to the cylindrical wave guide, the wall being positioned in an end plane of the cylindrical wave guide opposite to the output antenna. An arcuate slit is formed in the wall with the center of curvature of the slit being centered at the center axis of the cylindrical wave guide. This construction suppresses higher harmonics, and furthermore impedance matching and adjustment of the heating performance are facilitated.

High frequency heating device having an energy feed system including a

Cooking appliance with self-contained weighing system

An electromagnetic energy seal for use in a microwave oven comprises a first sealing cavity formed along at least one of a peripheral edge portion of an entrance opening of a heating chamber and a portion of a door for opening and closing the entrance opening of the heating chamber which is opposite to the peripheral edge portion of the entrance opening of the heating chamber, and a second sealing cavity disposed in the opening of the first sealing cavity. These first and second sealing cavities have a simple structure which produces high shield effects against the fundamental microwave frequency and the higher harmonic microwave frequency components thereof, respectively, and the adjustment and optimization of the choking frequency characteristics of the cavities can be made easy.

Microwave oven having an electromagnetic energy seal

A turntable drive mechanism for a microwave oven having an oven-defining structure having a bottom wall and a hingedly supported door for selectively closing and opening an access opening leading into the interior of the oven-defining structure. The turntable drive mechanism has a turntable assembly removably positioned on the bottom wall for rotation about its own center through a plurality of rollers situated between the turntable assembly and the bottom wall, and a plurality of magnets. Cooperating with these magnets carried by the turntable assembly are magnets carried by a rotary carriage driven by a drive unit in one direction and situated below the bottom wall and externally of the oven-defining structure. Rotation of the turntable assembly is induced by rotation of the rotary carriage by the effect of magnetic forces of attraction developed through the bottom wall between the magnets on the turntable assembly and the magnets on the rotary carriage.

Turntable drive mechanism in electronic oven

Growing community of inventors

Nara, Japan

Kimiaki Yamaguchi