Kabushiki Kaisha Toshiba

Tokyo Shibaura Electric Co., Ltd.

Tokyo Shibaura Denki Kabushiki Kaisha

Hisao Saito

Norio Tashiro

Tokuju Koinuma

Masaki Adachi

Kaichiro Nakai

Akira Kousaka

Toshio Kawaguchi

Masataka Komine

Heihachi Miura

Saburo Matsushita

Masanori Kinuno

Toshio Ikeda

In a magnetron for microwave oven, a high-voltage input terminal structure 30 is provided on a shield box 26 mounted on a magnetron unit 22. The high-voltage input terminal structure 30 has a cylindrical earth electrode 33, a cylindrical high potential inner electrode 32 and a central conductor 31a. The cylindrical earth electrode 33 is secured to the shield box 26 and the cylindrical high potential inner electrode 32 is coaxially arranged in the cylindrical earth electrode 33. The central conductor 31a is connected through an inductor 28 to a cathode lead 27 of the magnetron unit 22. An insulating resin 34b is filled in a gap between the cylindrical earth electrode 33 and the highpotential electrode 32 to form a capacitor section C. Cylindrical insulating sheaths 37, 38 are formed by the resin on the both sides of the capacitor section C. The capacitor section C and the cylindrical insulating sheaths, 37, 38 are integrally formed and continuously extended along a straight line.

High-voltage input terminal structure of a magnetron for a microwave oven

In a magnetron, anode vanes are radially arranged in an anode cylinder and fixed to the inner surface of the anode cylinder. A cathode is arranged along a tube axis in the anode cylinder. Pole pieces of dish like shape are fixed to openings of the anode cylinder and the anode cylinder is hermetically sealed by cylindrical chambers. Permanent magnet rings are arranged around the cylindrical chambers, respectively, and are magnetically coupled by a yoke. Each of the pole pieces has a flange section, a flat inner disk section and a coupling section extending from the flange section to flat inner disk section. The outer diameter of pole piece is larger than 160% the diameter of an envelope defined by inner ends of the anode vanes. A envelope space contacting the inner ends of the anode vanes has a predetermined magnetic field intensity distribution that is produced by a magnetic flux supplied from the pole pieces and has a difference of not more than 15% along the tube axis.

Magnetron for microwave oven

A magnetron unit is provided with anode cylinder with a number of vanes defining resonance cavities, and a cathode disposed along the axis of the anode cylinder. An axial interaction space into which a magnetic field is developed is disposed between the vanes and the cathode. Provided is a pair of main pole pieces with the interaction space located therebetween to supply the magnetic field into the interaction space. Permanent magnet members are magnetically coupled with the pair of the main pole pieces for supplying magnetic energy to the main pole pieces. The permanent magnet members are magnetically coupled with each other by a yoke. Auxiliary pole pieces are disposed at the top ends of the main pole pieces at a given interval. The auxiliary pole pieces are supported by bimetal members fixed to them. When the temperature of the permanent magnet member, the bimetallic members rises moves the auxiliary pole pieces toward the interaction space. A reduction of the magnetomotive force of each permanent magnet member is offset by a reduction of the interval between the pair of the auxiliary pole pieces.

Magnetron unit with a magnetic field adjusting means

A magnetron includes a high frequency generating source having an anode and a cathode, two power supply conductors for supplying electric power to the cathode of the high frequency generating source, filter circuits inserted in the power supply conductors for damping and suppressing the high frequency components leaking through the power supply conductors and a shield box covering the two power supply conductors and two filter circuits. Each of the filter circuits includes a capacitor and a choke which is comprised of an coreless type inductor made of coreless coil and a core type inductor made of ferrite-cored coil. The coreless type inductors of two filter circuits connected to the respective different power supply conductors are different each other in inductance.

Filter device for high frequency generating device

In a magnetron of the permanent-magnet-externally disposed-type wherein a pair of permanent magnets are disposed outside an anode cylinder, a yoke magnetically coupling the pair of permanent magnets to each other is extended along the side wall of an anode cylinder of the magnetron, and this anode cylinder is securely fixed to the yoke. The permanent magnets are each supported between the yoke and a seal plate for sealing the opening of the anode cylinder of the magnetron.

Magnetron with holding means to support a pair of permanent magnets

Growing community of inventors

Yokohama, Japan

Hisao Saito