Matsushita Electric Industrial Co., Ltd.

Isao Kasai

Kimiaki Yamaguchi

Koji Yoshino

Shinichi Sakai

Takashi Kashimoto

Toyotsugu Hatagawa

Susumu Murakami

Kenji Watanabe

Shigeki Ueda

Mitsuo Akiyoshi

Masaaki Sano

Tatsuji Isono

Akinori Otsuka

This invention provides a heating and cooking apparatus in which foods can be accommodated in a heating chamber with good maneuverability and an appropriate finish can be obtained. A temperature detector detects infrared radiation through an opening provided on a wall surface opposed to an opening part for taking in and out foods of a heating chamber. The temperature detector detects the temperature of a plurality of parts on a sealing having the substantially same electric wave penetrability as that of the bottom surface of the heating chamber. Accordingly, even when two foods are arranged right and left irrespective of the size of the foods, the temperature of both the foods can be detected. Then, the user does not needs to extend a hand to the interior of the heating chamber and arrange the foods in front and back positions.

Temperature detection unit in a high-frequency heating and cooking apparatus

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 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 heating apparatus is provided with the gas sensor for detecting gas or steam generated from an object to be heated and a weight sensor for detecting the weight of the object to be heated. The signal level of the gas sensor indicates whether the change in the amount of the gas or the steam in the exhaust guide portion is a predetermined value of gas or steam generated from the object, to determine the kind and condition of the object to be heated. Also, change in the signal level of the gas sensor is compared to the predetermined value at a detection time period which is based on the weight of the food detected by the weight sensor, to decide whether to continue or stop heating.

Growing community of inventors

Nabari, Japan

Isao Kasai