Panasonic Corporation

Matsushita Electric Industrial Co., Ltd.

Fumihiro Tateno

Yasuhiro Torigoe

Masayuki Isayama

Youichi Nakamura

Masaya Yoshihara

A heating roller performs electromagnetic induction heating, and includes a first exciting coil that heats the heating roller, a first degaussing coil that decreases magnetic fields of the first exciting coil, and a first axial direction core that guides magnetic fluxes, to make up a magnetic circuit between the first axial direction core and the heating roller. The width of a heat zone is controlled in agreement with a sheet feeding area. Thus, the capability to control a temperature increase in a non-sheet-feeding area of the heating roller is enhanced. Power can be saved during continual feeding of small recording sheets.

Induction heater with directional cores

A fixing apparatus of the present invention for an electronic induction heating system includes a heat roller and a magnetic excitation coil that generates Joule heat within the heat roller. The fixing apparatus includes a coil positioner that positions the magnetic excitation coil around a portion of a periphery of the heat roller, a fixing roller that fixes toner image on a recording medium, and a belt that contacts a portion of a periphery of the heat roller and the fixing roller to conduct the generated heat from the heat roller to the fixing roller. The coil positioner further has a surface of first curvature substantially identical to a curvature of a periphery of the heat roller at an opposition area, the opposition area being opposite to a contact area where the heat roller makes contact with the belt. The coil positioner is spaced from the belt by a predetermined distance. The coil positioner further has a first extension extending from a first end of the opposition area of the coil positioner and a second extension extending from a second end of the opposition area of the coil positioner. The first extension and the second extension are spaced from the belt distances larger than the predetermined distance.

Wire winding apparatus and method for producing magnetic excitation coil

Fixing apparatus, image forming apparatus, wire winding apparatus and method for producing magnetic excitation coil

Growing community of inventors

Tochigi, Japan

Fumihiro Tateno