Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Panasonic Intellectual Property Management Co., Ltd.

Takahiro Miyauchi

Izuo Hirota

Yuji Fujii

Atsushi Fujita

Naoaki Ishimaru

Tomoya Fujinami

Koji Niiyama

Akira Kataoka

Fumitaka Ogasawara

Masafumi Sadahira

Katsuyuki Aihara

Kouji Niiyama

Shinji Kondo

Kenji Watanabe

Hiroshi Tominaga

Hideki Omori

Takayuki Hayami

Hidekazu Yamashita

Takeshi Kitaizumi

Ryuuji Nagata

Nobuo Genji

Nobuyoshi Makio

Yasuhiro Ban

Hirofumi Inui

Kazuyoshi Shichi

Manabu Takahashi

Naoki Yamasaki

Kohji Niiyama

An induction heating cooker includes a top plate on which an object to be heated is placed, a plurality of heating coils disposed adjacent to one another below the top plate to generate inductive magnetic fields to heat the object to be heated, a plurality of temperature detectors operable to detect a temperature of the object to be heated; and a controller operable to control operating states of the heating coils based on detection results of the temperature detector, wherein the plurality of temperature detectors are disposed widely below the top plate, and the number of the temperature detectors is less than the number of the heating coils.

Induction heating cooker

Disclosed is an induction cooking device that is not likely to be affected by induction heating and wherein boiling-over can be detected. An induction cooking device has: a top plate on which a cooking container is placed; a heating coil that generates an induction magnetic field for heating the cooking container; a heating control unit that controls the heating power of the cooking container by controlling the high-frequency current supplied to the heating coil; electrodes disposed in a lower surface of the top plate; and an electrostatic capacity detector that detects changes in electrostatic capacity occurring in the electrodes when articles to be cooked contact with the top plate. When the electrostatic capacity detector senses changes in the electrostatic capacity of the electrodes, the heating control unit decreases or stops the heating power of the cooking container, and the electrodes are disposed outside of the outer circumference the heating coil.

Inductive heating apparatus

There is provided a heating/cooking equipment capable of accurately determining boiling over. The heating/cooking equipment includes: a top plate () connected to a reference potential; a heating unit () configured to heat an object to be heated placed on the top plate; an electrode () arranged under the top plate; a capacitance detecting unit () configured to detect the electrostatic capacitance of the electrode; a boiling over detecting unit () configured to detect whether or not a material to be cooked in the object to be heated has boiled over on the top plate, based on a value of the electrostatic capacitance detected by the capacitance detecting unit; and a control unit () configured to control the heating operation of the heating unit based on a boiling over detection result from the boiling over detecting unit. The capacitance detecting unit () detects a change in the electrostatic capacitance of the electrode by exploiting capacitive coupling between the electrode and the reference potential which is enhanced by increase in a boiled over amount of the material to be cooked with moisture contained in the material to be cooked functioning as a dielectric when the material to be cooked boils over on the top plate.

Heating/cooking equipment

The present invention provides an induction heating cooker, which is structured to cut off visible light being incident upon an infrared sensor, yet being capable of more accurately sensing any abnormality of the infrared sensor before heating is started. To this end, the induction heating cooker includes a sensor failure sensing-purpose light emitting portion that emits visible light for sensing any failure of an infrared sensor, a visible light cutting filter provided on a surface of a printed circuit board holding the infrared sensor so as to cover the field of view of the infrared sensor, and a control unit that limits the output of an inverter circuit supplying a high-frequency current to a heating coil when the output of the infrared sensor is equal to or less than a threshold value in a situation where the sensor failure sensing-purpose light emitting portion is lit up. The infrared sensor receives the visible light from the sensor failure sensing-purpose light emitting portion to irradiate inside the visible light cutting filter.

An induction heating device includes the following elements: a resonance circuit; a power factor improvement circuit for boosting rectified output, supplying the output to an inverter, and improving the power factor of a commercial alternating current; and a load material detector for detecting the material of the load. The inverter includes switching elements forming a full-bridge circuit. The drive frequency of the switching elements is switched between a frequency substantially equal to a resonance frequency of the resonance circuit and a frequency substantially 1/n time (n being an integer equal to or larger than two) thereof, according to a detection result of the load material.

Induction heating apparatus

An induction heating cooking device has an inverter including a resonant circuit, and a heating output control part. The resonant circuit has a resonant capacitor and a heating coil that is magnetically coupled to a load. The inverter has first and second switching elements. The heating output control part performs control by inverting the rate values of the driving periods of the first and second switching elements. The driving of the inverter is thus controlled so that substantially the same heating output is obtained to average the losses of the first and second switching elements.

Induction heating cooking device

A detector is operable to detect a displacement of a load by an ascending force based on a period of time from a time a heating output of an inverter drops from a predetermined level to a first level, to a time the heating output returns back to a second level larger than first level. Thereby, the detector distinguishes an intentional removal of the load from the displacement of the load by the ascending force. An induction heater including the detector reduces the displacement of the load by the ascending force and stops the heating of the load when the load is removed intentionally.

Induction heater with controlled current to heating coil

In an induction heating apparatus, in order to decrease the buoyancy exerted on an object to be heated which is made of a material having high electrical conductivity and low magnetic permeability, such as aluminum, an electrical conductor is provided between a heating coil and the object to be heated, thereby increasing the equivalent series resistance of the heating coil. Hence, the current of the heating coil, which is required for obtaining a desired heating output, is decreased, whereby the buoyancy of the object to be heated can be decreased. In addition, the electrical conductor is divided into two halves, and they are arranged in a circular arc form with a clearance provided therebetween and made close contact with the bottom face of a plate, whereby the temperature rise of the electrical conductor can be restricted. Furthermore, the heat of the electrical conductor is transferred and dissipated to the object to be heated, whereby the heating coil and the like are not damaged even if the electrical conductor is heated. An electrical conductor temperature sensor for detecting the temperature of the electrical conductor is provided; when the detection temperature becomes a predetermined temperature, the heating output of a drive circuit is decreased, whereby the heat generation of the electrical conductor is decreased and the heating coil and the like are not damaged by heat.

Induction heating device

An induction heater having a safety function of lowering or stopping the heating power when an object to be heated moves, the safety function hardly interfering with the cooking activities of a user is provided. The induction heater includes an inverter circuit, an output detection section for detecting the magnitude of the inverter circuit, a first movement detection section, and a storage section for storing a control value before the first movement detection section detects a movement of the object. In a reach control mode, the output of the inverter circuit is gradually increased to a target. In a stable control mode, the output of the inverter circuit is maintained at the target. When the first movement detection section detects a movement of the object, a control section shifts to a first output mode in which a control value derived from the stored control value is output.

Induction heater

When a pan made of a non-magnetic material, such as aluminum, is used for cooking while the temperature is being controlled, a notice is made to the user to the effect that the temperature control function has been stopped and that the temperature should be manually adjusted, when the material detection section detects that the pan is made of a non-magnetic material or a pan floating phenomenon has occurred, in order to prevent abnormal increase in the temperature of the pan due to incorrect temperature detection caused by the pan floating phenomenon, a set temperature is lowered.

An induction heating device prevents an object to be heated from being displaced and buoyed from a mounting surface due to an mutual action of repulsive forces between the object to be heated and an induction heating coil. The induction heating device includes a source-current detector for detecting a source current input to a high-frequency inverter including the induction heating coil and an inverter circuit, a source-current change detector for measuring a change against time of a magnitude of the source current to detect a displacement and buoying of the object to be heated, such as a cooking pot, and a change examining unit. The controller controls an output of the high-frequency inverter in response to a detection result of the change examining unit. The induction heating device prevents the cooking pot from being displaced and buoyed even if the pot is not touched by a user at startup of heating or during the heating operation, and is inexpensive and safe.

An induction heating apparatus can heat aluminum pot etc. with pot vibration noise being suppressed. During a turn-on time of second switching device , an energy is accumulated at choke coil , and at the same time a resonant current with a shorter period than the turn-on time of second switching device or a driving time of first switching device is generated at heating coil , so that during turn-off of second switching device , i.e., during on-time of first switching device , the energy accumulated at choke coil is transferred to second smoothing capacitor . And then the output power is supplied from smoothing capacitor to heating coil , thereby reducing the pot vibration noise, which is caused by pulsating current of input voltage.

A heating roller device which incorporates a metal roller having a curier temperature adjusted to an appropriate level and enabling a self-temperature-controllability and which has a structure that the metal roller is induction-heated by an induction heating section. A method of manufacturing the foregoing metal roller according to the present invention has a step of joining a pipe, which is made of temperature-sensitive magnetic metal, and the composition of which has been adjusted so as to have a predetermined curier temperature, and metal having a resistivity lower than that of the temperature-sensitive magnetic metal to each other by a drawing work in such a manner as to prevent formation of any gap. Thus, an induction heating pipe exhibiting an excellent heating characteristic is manufactured.

Growing community of inventors

Hyogo, Japan

Takahiro Miyauchi