Microwave heating device and image fixing apparatus using the same

A microwave heating device comprising:

• a microwave generating portion outputting a microwave;
• a conductive heating chamber into which the microwave is led from one end thereof;
• a short-circuited terminal section short-circuiting an other end of the heating chamber;
• an opening provided in the heating chamber and passing a member to be heated through an inside of the heating chamber in a direction non-parallel to a traveling direction of the microwave;
• and
• conveying members including a pair of members, the pair of members sandwiching the member to be heated there between to pass the member to be heated through the opening in the non-parallel direction,
• wherein the heating chamber is divided into a plurality of spaces along the traveling direction to a terminal end by a barrier made of a conductive material,
• wherein in all the spaces or more than one of the spaces, phase shifters having different lengths in the traveling direction and made of a dielectric having a higher permittivity than air are inserted at the terminal end toward the microwave generating portion so that positions in the traveling direction of nodes of standing waves formed in the spaces are different from each other,
• wherein in at least more than one of the spaces, impedance adjusters having different lengths in the traveling direction and made of a dielectric having a higher permittivity than air are inserted in positions on an upstream side of the passing region of the member to be heated so as to reduce a difference in impedance in the spaces including the phase shifters from an inlet of the heating chamber into which the microwave enters to the terminal end.

A microwave heating device comprising:

• a microwave generating portion outputting a microwave;
• a conductive heating chamber into which the microwave is led from one end thereof;
• a short-circuited terminal section short-circuiting an other end of the heating chamber;
• an opening provided in the heating chamber and passing a member to be heated through an inside of the heating chamber in a direction non-parallel to a traveling direction of the microwave;
• conveying members including a pair of members, the pair of members sandwiching the member to be heated therebetween to pass the member to be heated through the opening in the non-parallel direction;
• and
• the heating chamber having:
• a barrier made of a conductive material and dividing the heating chamber into a plurality of spaces in the traveling direction to a terminal end;
• in all the spaces or more than one of the spaces, phase shifters having different lengths in the traveling direction and made of a dielectric having a higher permittivity than air being inserted at the terminal end toward the microwave generating portion so that the positions in the traveling direction of nodes of standing waves formed in the spaces are different from each other;
• and
• in at least more than one of the spaces, impedance adjusters having different lengths in the traveling direction and made of a dielectric having a higher permittivity than air being inserted in the positions on an upstream side of a passing region of the member to be heated so as to reduce a difference in impedance in the spaces including the phase shifters from an inlet of the heating chamber into which the microwave enters to the terminal end.

A microwave heating device comprising:

• a microwave generating portion outputting a microwave;
• a conductive heating chamber into which the microwave is led from one end thereof;
• a short-circuited terminal section short-circuiting another end of the heating chamber;
• a tuner provided between the microwave generating portion and the heating chamber;
• an opening provided in the heating chamber and passing a member to be heated through an inside of the heating chamber in a direction non-parallel to a traveling direction of the microwave;
• conveying members including a pair of members, the pair of members sandwiching the member to be heated there between to pass the member to be heated through the opening in the non-parallel direction;
• and
• an electric field transformer made of a high dielectric having a higher permittivity than air, the transformer having a width more than (4N−3)λg′/8 and less than (4N−1)λg′/8 where λg′ is a wavelength of a standing wave in the high dielectric and N (N>0) is a natural number, the transformer being inserted in a position including a node of a standing wave between the tuner and the heating chamber.

A microwave heating device comprising:

• a microwave generating portion outputting a microwave;
• a conductive heating chamber into which the microwave is led from one end thereof;
• a short-circuited terminal section short-circuiting another end of the heating chamber;
• a tuner provided between the microwave generating portion and the heating chamber;
• an opening provided in the heating chamber and passing a member to be heated through an inside of the heating chamber in a direction non-parallel to a traveling direction of the microwave;
• conveying members including a pair of members, the pair of members sandwiching the member to be heated there between to pass the member to be heated through the opening in the non-parallel direction;
• and
• a feeding roller for circulatably moving each conveying member, and a driving portion for rotatably driving the feeding roller.