Matsushita Electric Industrial Co., Ltd.

Panasonic Intellectual Property Management Co., Ltd.

Panasonic Corporation

Makoto Mihara

Kenji Yasui

Kazuho Sakamoto

Tomotaka Nobue

Yoshiharu Oomori

Haruo Suenaga

Shinichi Sakai

Kenzo Ohji

Hisashi Morikawa

Hideki Omori

Yoshiaki Ishio

Takeshi Kitaizumi

Shuji Itou

Hideaki Moriya

Masanobu Inoue

Shigeki Ueda

Daisuke Bessyo

Shigeru Kusunoki

Yoshiharu Omori

Nobuo Shirokawa

Naoyoshi Maehara

Yasuhiro Umekage

Takahiro Matsumoto

Toyotsugu Matsukura

Toshiyuki Okajima

Masato Matsuda

Takao Shitaya

Yohzoh Ishimura

Emiko Ishizaki

Yoshiaki Watanabe

Hiokaki Moriya

Hidetomo Nagata

Takeshi Irii

Toyotsubu Matsukura

Daisuke Bessho

A microwave heating device according to the present invention includes a microwave oscillation portion including a reference-signal oscillator formed from a quarts oscillator, phase variable portions and phase-locked loops and, further, includes a control portion for controlling the microwave oscillation portion, and plural radiation portions placed on a wall surface of a heating chamber for housing a to-be-heated object, wherein microwaves supplied to plural microwave feeding points provided in the radiation portions are controlled in phase and electric power, thereby controlling the aspect of radiations of microwaves radiated from the radiation portions.

Microwave heating device

A microwave heating device mountable to an electric device, includes: a commercial power supply; an AC/DC converter which outputs a plurality of DC voltages according to power supplied from the commercial power supply; a controller which receives power from the AC/DC converter and totally controls the electric device; a microwave processing device using a compound semiconductor which receives a plurality of outputs of the AC/DC converter and outputs a microwave; and a plurality of loads connected between, of the DC voltages output from the AC/DC converter, a predetermined Vd voltage and ground through a plurality of contacts. The loads form a group of electric components in the electric device. The controller controls power supply to the loads, and controls on/off of the contacts to drive the loads by the Vd voltage regardless of the voltage of the commercial power supply.

In order to provide a microwave heating device and a microwave heating control method which are capable of uniformly heating a to-be-heated object in a desired state, by employing plural feeding portions provided in a heating chamber on the basis of information about reflected electric power from the respective feeding portions; a control portion controls to supply microwave electric power from plural feeding portions to a heating chamber by operating a microwave generating portion at a heating frequency for heating a to-be-heated object, estimates a heating state for the to-be-heated object on the basis of per-unit-time increase/decrease change states of detected levels of detection signals detected by electric-power detection portions, and controls the heating frequency and the microwave electric power supplied from the feeding portions to the heating chamber.

Microwave heating device and microwave heating control method

A microwave heating apparatus includes, within a heating room, a placement table having a horizontal placement surface for placing an object to be heated, and a plurality of feeding portions which are placed on a wall surface of the heating room for supplying microwave electric power to the heating room. The microwave heating apparatus is adapted to relatively move the position of the straight line connecting two feeding portions to each other, with respect to the object to be heated, through a movement mechanism portion, and to detect a phase difference between the microwave electric powers which minimizes reflected electric power returning from the heating room to the two feeding portions, for detecting the state of placement of the object to be heated on the placement table.

Microwave heating apparatus

In a microwave heating apparatus of the invention, microwaves from oscillation partsare divided into a plurality of microwaves by power division partsand inputted to amplification parts, and desired microwave powers from the amplification parts are supplied from feeding partsto a heating chamber. Reflected powers reflected from the heating chamber to the amplification parts via the feeding parts are detected by power detection parts. Each of the feeding parts has a plurality of antennas for supplying the microwaves having different characteristics to the heating chamber, and a control partextracts an oscillating frequency with which the reflected powers detected by the power detection parts are minimum, and causes the oscillation parts to oscillate at the extracted oscillating frequency so as to supply the microwaves having the different characteristics from the plurality of antennas to the heating chamber.

A microwave heating apparatus includes a microwave generation partusing a semiconductor element, and first and second heating chambersto each of which a microwave generated in the microwave generation part is fed. A reflected microwave returned from at least one of the first and second heating chambersto the microwave generation part is transmitted to the other heating chamber by a circulation type non-reciprocal circuit, so that generated power of the microwave generation part is substantially completely consumed upon heating of an article to be heated.

There is constructed a constitution such that a shunt resistoris interposed in series with a portion capable of measuring an output current of a unidirectional power source portionof a high frequency heating apparatus and a voltage generated at the shunt resistoris outputted by a buffer. Further, an operational amplifierhaving a high input impedance is used for the buffer. Further, a diode bridgeand a semiconductor switching elementare fixed to a common heat radiating plate, the heat radiating plateis formed with a notched portionto thereby ensure insulating distances to the diode bridgeand the semiconductor switching element, and the shunt resistoris arranged on a straight line the same as that between the diode bridgeand the semiconductor switching element

High frequency heating apparatus

The present invention provides a boosting transformer for microwave oven, which is low in high-frequency loss, hardly saturated, small in size and easy to produce. The boosting transformer includes a rod-like ferrite core; and primary, secondary and heater windings wound around the rod-like ferrite core and piled up side by side in a direction of an axis of the rod-like ferrite core. It also includes a metal core formed from a long metal thin plate rolled by a plurality of times into a square-ring having one inner diameter larger than each of outer sizes of the primary, secondary and heater windings and the other inner diameter larger than a total size of the three windings piled up side by side, the metal core being arranged opposite to the rod-like ferrite core through a gap so as to be fitted toward the rod-like ferrite core from the outside of the primary, secondary and heater windings.

Magnetron drive boosting transformer

A Hall element (H) is arranged at an air gap of a choke coil (). Power semiconductor elements (P) and (P) are attached to a heat radiation fin () directly by soldering. A rectangular-hollow-shaped metal core () is formed by winding a long metal thin plate multiple turns into a rectangular-hollow-shape and is fitted to a bar shaped ferrite core () from outside of the primary winding () and the secondary winding (). The inner diameter of one side of the rectangular-hollow-shape core is larger than both outer diameters of the primary winding () and the secondary winding () and the inner diameter of the other side of the rectangular-hollow-shape core is larger than the height of the primary winding () and the secondary winding (). The rectangular-hollow-shape () core is arranged such that an air gap (G) exists between the rectangular-hollow-shape core () and the bar shaped ferrite core ().

Power-supply unit for electronic oven

It is provided a magnetron drive power supply wherein a series connection body of first and second semiconductor switch elements that can be brought into reverse conduction and a series connection body of first and second diodes are connected in parallel, first and second capacitors are connected in parallel to the first and second diodes, a series circuit of a commercial power supply and a primary winding of a high-voltage transformer is connected between a connection point of the first and second semiconductor switch elements that can be brought into reverse conduction and a connection point of the first and second diodes, and output of a secondary winding of the high-voltage transformer energizes a magnetron through a high-voltage rectification circuit.

Magnetron drive power supply

A primary winding ( ) and a secondary winding ( ) are layered concentrically with a magnetic substance forming a main magnetic circuit ( ) and the magnetic resistance of a subordinate magnetic circuit ( ) placed between the primary winding ( ) and the secondary winding ( ) is adjusted, whereby a concentric multilayer winding transformer having an arbitrary coupling coefficient can be provided.

Magnetron drive step-up transformer and transformer of magnetron drive power supply

High-voltage diodes ( ) and ( ) and high-voltage capacitors ( ) and ( ) making up a high-voltage circuit are connected and are molded of a resin ( ) except that terminals ( ) and ( ) are drawn out as a small-sized high-voltage module ( ) in one piece.

A high frequency heating apparatus including a circuit for driving a magnetron. A circuit comprises a leakage transformer, a second capacitor connected in series to primary coil of said leakage transformer, a second switching device connected in parallel with a series circuit of said primary coil and second capacitor, a first capacitor connected in parallel with said second switching device, and a first switching device connected in series to said second switching device. Under a structure of the present invention, the switching device and the leakage transformer, both being the key components of the circuit, may respectively be used in common either on a circuit of 200V-240V commercial power supply or on a circuit of 100V-120V commercial power supply. This enables volume production of the key components, which leads to a benefit of reduced cost of the components as well as the cost of heating apparatus.

A switching device is employed in a power supply for driving a magnetron with lower withstand voltage and better controllability. A high frequency heating apparatus comprises a power supply, a leakage transformer connected to the power supply, a first switching device connected in series to a primary coil side of the leakage transformer, a first capacitor, a series circuit of a second capacitor and a second switching device, a driving circuit having an oscillator for driving the first switching device and the second switching device, a rectifier connected to a secondary coil side of the leakage transformer, and a magnetron connected to the rectifier. With this configuration, voltage applied to the first switching device can be clamped, and at the same time, the OFF time can be freely adjustable by the effect of the second capacitor and the second semiconductor switching device.

Switching power supply for high frequency heating apparatus

In a microwave heating device, a propeller fan is mounted on a drive shaft of a motor that in vertically positioned parts of a high frequency power supply unit are arranged in the order of a power control semiconductor device and a high-voltage transformer along the direction of revolution of the propeller fan. The motor is secured to a support member formed by a motor cover attached to the casing of the propeller fan. The fan and high frequency power supply unit are mounted to a first frame and a second frame, both of which are bent and connected at a connecting portion and fixed in an approximately 'L' shape, while an airflow path is defined by a first guide wall and a second guide wall to cool the parts of the high frequency power supply unit. An airflow path is formed by a plurality of guide walls provided on the two frames, and a communicating hole is provided in proximity to the connecting portion of the two frames. The propeller fan is so arranged as to revolve at a low r.p.m. after stopping the microwave heating.

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Nara, Japan

Makoto Mihara