Konica Minolta Business Technologies, Inc.

Minolta Company, Ltd.

Masami Miyazaki

Yasuhiro Ohno

Ken Tanino

Makoto Fujii

Eiichi Sano

Toshiya Natsuhara

Yutaka Otsuka

Yoshihiro Fukuhata

Naoki Yamamoto

Koji Takahashi

Kazuo Mohri

Yoshihisa Fujimoto

Shoukou Gon

A fixing device has a fixing belt, a trembler coil for heating the fixing belt with magnetic flux, a ferrite core around which the trembler coil is wound, and a heater for heating the ferrite core. The ferrite core has a Curie temperature which is between a fixing temperature of the fixing belt and a smoking start temperature of the fixing belt. The heating of the ferrite core with the heater allows the temperature of the ferrite core to reach the Curie temperature before the temperature of the fixing belt reaches a smoking start temperature. Thereby, an excessive rise in temperature of the fixing belt is suppressed, which prevents the fixing belt from smoking and igniting.

Fixing device for use in an image forming apparatus

A fixing device has a fixing roller including an inside roller, an outside roller and a regulation member. The regulation member is disposed outside of both ends of the outside roller in the axial direction to regulate axial movement of the outside roller. An axial length of the contact face, where the pressure roller contacts with the outside roller, is smaller than an axial length of the outside roller. Thereby, both ends of the outside roller hardly receive bending deformation caused by pressure of the pressure roller. This makes it possible to reduce stress exerted to both ends of the outside roller, and therefore, the ends of the fixing roller are prevented from being damaged to enhance durability of the fixing roller.

Fixing device

An induction heating device for inductively heating an object to be heated which is formed of conductive material has a holder. The device also has a coil for inductively heating the object. The coil is supported by the holder. The coil is composed of a plurality of turns of conductor forming a layer, which is positioned along the object. Between conductor sections of the coil through which electric currents respectively flow in the same direction is formed a gap through which temperature of the object is detected. The device is capable of accurately detecting the temperature of heating region of the object, at low cost, and capable of increasing stability and safety in control of the temperature.

Induction heating device, induction heating fixing device and image forming apparatus

An induction heating device for inductively heating an object to be heated which is formed of conductive material has a holder. The holder is positioned outside the object. The device has an exciting coil for inductively heating the object. The exciting coil is supported by the holder. The exciting coil is composed of a plurality of turns of conductor forming a layer, which is positioned along the object. The device also has a demagnetizing coil which is positioned along the layer of the exciting coil. In the demagnetizing coil, a back electromotive force is induced in accordance with a magnetic field produced by the exciting coil, so as to cancel the magnetic field. Stability in the temperature control for the object such as a heating roller can be improved by effective function of the demagnetizing coil. The device can be miniaturized and configured at low cost.

A heat fixing device for heat fixing a toner image to a receiving medium having a pair of fixing belts in an endless form; a pair of rotary members individually disposed on a respective inside circumference of the fixing belts and pressed against each other via the fixing belts; a pair of fixing members individually disposed on the respective inside circumference of the fixing belts and pressed against each other via the fixing belts; and a heating element for heating at least one of the fixing belts, wherein the fixing belts contact the rotary members and the fixing members only at a respective portion thereof via which the respective pair of rotary members and fixing members are pressed against each other.

Heat fixing device and image forming apparatus

The fixing device of the present invention comprises a heating roller having an internal heating device; a flexible fixing belt wrapped around the exterior side of the heating roller and having a circumferential length longer than the circumferential length of the heating roller; and a pressure roller for pressing against the heating roller through the fixing belt, wherein a slack part of the fixing belt is formed on the downstream side from the pressure contact part between the heating roller and the pressure roller in the direction of transport of the recording medium, such that this slack part touches the exterior surface of the pressure roller.

Growing community of inventors

Itami, Japan

Masami Miyazaki