Kabushiki Kaisha Toshiba

Tokyo Shibaura Denki Kabushiki Kaisha

Masayuki Aoki

Yukio Suzuki

Takamichi Sujaku

Koichi Miyazaki

Nobuichi Nishimura

Nobuaki Ohta

Kazuo Kitamura

Ryuho Narita

Kazunori Ishii

Yoshio Okamura

Takumi Ohno

Masahiko Wada

Hisao Kano

A heating apparatus such as a microwave oven includes a magnetron and a heating chamber for accommodating food to be heated by microwaves generated by the magnetron. The heating chamber has a front opening opened and closed by a door. An operation panel is mounted to be adjacent to the door. The operation panel includes a panel section and an operation section mounted on the panel section and has a function of displaying a plurality of pieces of cooking information. The operation section includes a liquid crystal element subsection including a nematic curvilinear aligned phase (NCAP) liquid crystal permitting light to pass through it when voltage is applied to it, an indicia subsection laid on the liquid crystal element subsection and having a plurality of indicias corresponding to the pieces of cooking information, respectively, and a switch subsection including a plurality of switches corresponding to the indicias of the indicia subsection, respectively. A heat-resistant panel frame is mounted between the door and the operation section. The panel frame cuts off heat transmission through a gap between the heating chamber and the door and heat transmission from the door to the liquid crystal element subsection.

Microwave oven with NCAP liquid crystal operation display panel

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. One of the heat sources in accordance with the selected cooking mode is controlled on the basis of a cooking program of the selected cooking mode by the microcomputer.

Microwave oven with automatic cooking mode selecting function

A microwave oven includes a magnetron generating microwaves which are irradiated onto food for heating the same, a circuit substrate incorporating an electric circuit for driving and controlling the magnetron, circuit means for generating both an electrical alarming signal and a high-frequency electrical signal, and a sound producer producing an alarming sound regarding a heating operation when supplied with the alarming electrical signal and producing ultrasonic waves for the repelling of insects when supplied with the high-frequency electrical signal.

Microwave oven

A microcomputer-based control device for microwave ovens includes a timer defining an operation period of a magnetron and incorporated in the microcomputer, an encoder generating electrical pulses, the number of which is in accordance with an amount of angular displacement of an operation knob, the encoder being independent of the microcomputer, first and second semiconductor switches for starting an operation of the magnetron in response to either any one or a plurality of a pulse train generated by the encoder, the semiconductor switches being incorporated in the microcomputer, and a counter for setting, at the timer, a cooking period in accordance with the numer of pulses of the pulse train generated by the encoder.

Cooking appliances

In a high frequency cooking apparatus including a magnetron, a fan motor, turntable motor, a plurality of relays for controlling them and a microcomputer controlling the relays, the microcomputer is provided with a relay test program. The relay test program is executed when specific two cooking menu selecting keys are simultaneously depressed. Consequently, pulses are sequentially supplied to all the relays and simultaneously, relay identification marks are sequentially displayed on a display unit. Based on the mechanical operation sound from each relay and the displayed content, an operator determines whether or not each relay is normal.

Heating cooking appliance with relay testing

A high-frequency heat source supplies a predetermined high-frequency heat output. An inverter circuit receives an AC input and supplies a high-frequency output to drive the high-frequency heat source. The inverter circuit includes a circuit for rectifying the AC input, and a switching element for switching a DC output from the rectification circuit. A timing circuit is coupled to the inverter circuit to detect a switching timing of the switching element to the inverter circuit. A controller outputs an ON/Off signal having a predetermined duty ratio corresponding to a heating output set value associated with the predetermined high-frequency heating output. The ON/Off signal is output at a predetermined timing in response to a detection output from the timing circuit. A drive circuit drives the switching element in the inverter circuit in response to the ON/Off signal output from the controller. A first isolation circuit electrically isolates the timing circuit from the controller. A second isolating circuit electrically isolates the controller from the drive circuit.

High-frequency heating apparatus having digital controlled inverter

A high-frequency heating source supplies a predetermined high-frequency heating power. An AC input is supplied to an inverter circuit. The inverter circuit generates a high-frequency output signal for driving the high-frequency heating source. The inverter circuit comprises a rectifier circuit for rectifying the AC input, and a switching element for switching the DC output supplied from the rectifier circuit. The inverter circuit is controlled by an inverter control circuit. A processor supplies set heating-output data associated with the high-frequency heating power to the inverter control circuit. The inverter control circuit comprises a counter and an on/off signal generator. The counter is set to a on-period in accordance with the set heating-output data, and performs counting operation. The on/off signal generator generates an on/off signal in accordance with a count value of the counter. A driving circuit drives the switching element of the inverter circuit in response to the on/off signal supplied from the inverter control circuit.

High-frequency heating apparatus having a digital-controlled inverter

A high frequency heating source provides a predetermined high frequency heating output. An inverter receives an AC input and provides a high frequency output for driving the high frequency heating source. The inverter includes a rectifier for rectifying the AC input and a switching element for switching a DC output from the rectifier. The microprocessor outputs an ON/OFF signal having predetermined ON and OFF periods in accordance with a set output value associated with the high frequency heating output. A driver drives the switching element of the inverter in accordance with the ON/OFF signal output from the microprocessor.

High frequency heating apparatus using microcomputer controlled inverter

An inverter rectifies an AC input to produce a DC output and switches the DC output so as to selectively obtain a high-frequency output for microwave or induction heating. A microwave heating unit is coupled to the inverter, receives the high-frequency output for microwave heating, and generates a first heating power of a microwave. An induction heating unit is coupled to the inverter, receives the high-frequency output for induction heating, and generates a second heating power of electromagnetic induction. An output setting unit selectively sets an output setting value for the first or second heating power. An input detector detects a current value of the AC input to the inverter. A controller compares the output setting value from the output setting section with the current value from the input detector, outputs a control signal representing the comparison result to the inverter so as to control the output from the inverter, and causes the microwave heating unit or induction heating unit to selectively generate the first or second heating power.

Composite cooking system having microwave heating and induction heating

In an induction heat cooking apparatus of the invention, an electromagnetic field is generated by a heating coil, and the generated electromagnetic field is supplied to a load so that the load is inductively heated. The cooking apparatus includes an exciter circuit for exciting the heating coil to generate the electromagnetic field; a temperature set circuit for providing a temperature set signal which designates a given target temperature of the load; and a temperature measure circuit for measuring the temperature of the load to generate a temperature measure signal which represents the measured temperature of the load. The cooking apparatus further includes a difference detector circuit for detecting a difference between the temperature set signal and the temperature measure signal and generating a difference signal. The exciter circuit receives the difference signal so as to control heat power for the heating coil.

Induction heat cooking apparatus

A control circuit for a microwave oven with a mechanical switch locking assembly, wherein a cooking start switch is available to turn on after closing a door and is turned off when the door is opened. The control circuit includes a relay for connecting a power source to energize a magnetron, and control means for controlling the relay. The control means enables the relay to connect the power source with the magnetron when the cooking start switch is turned on after connecting the control means with the power source. If the cooking start switch is already turned on prior to connecting the microwave oven to the power source, the operator must first open the microwave oven door, thus opening the start switch, and subsequently closing the door and closing the start switch. This safety procedure encourages the operator to insure that food products are placed in the oven, thus reducing the danger of operating the oven without a load.

Control circuit for a microwave oven

A control circuit for controlling a magnetron of a microwave oven includes a microcomputer output control means for controlling the energy output of the microwave oven, and a means for controlling the magnetron in response to a time signal and a food temperature signal. The control circuit includes a back-up circuit to de-energize the magnetron when cooking is complete in the event of a malfunction of the microcomputer.

Growing community of inventors

Ichinomiya, Japan

Masayuki Aoki