Konica Minolta, Inc.

Konica Minolta Business Technologies, Inc.

Hirotaka Kanou

Noboru Yonekawa

Hidetoshi Katayanagi

Tetsuya Kagawa

Hiroyuki Maeda

Etsuaki Urano

Masashi Sonoyama

Yoshikazu Kuribayashi

Tomohiro Takagi

An image forming apparatus includes: a fixing roller that fixes an unfixed image to a medium; a drive motor of the fixing roller, and a hardware processor that acquires information regarding a state of the image forming apparatus or information regarding a state of the medium, and controls a number of rotations of the drive motor between a preset upper limit value and a preset lower limit value, wherein the hardware processor changes the upper limit value and the lower limit value while maintaining a difference between the upper limit value and the lower limit value on a basis of the acquired information.

Image forming apparatus

A fixing apparatus includes a heating rotator which generates heat with an induced current, an excitation coil arranged outside the heating rotator, a pressure roller which rotates with paper being held between the pressure roller and the heating rotator, the paper having a toner image developed thereon, and a relative position changer which changes a relative position of the excitation coil and the heating rotator to a first relative position when the toner image is being fixed to the paper and to a second relative position when the toner image is not being fixed to the paper. In a cross-section perpendicular to a rotation axis of the heating rotator, a distance from a point in an outer circumferential surface of the heating rotator closest to the pressure roller to the excitation coil is shorter at the second relative position than at the first relative position.

Fixing apparatus and image forming apparatus

A fuser including a fusing roller member configured to heat an unfixed toner image on a recording material, and a pressure roller member making pressure-contact with the fusing roller member, the fuser configured to fix the toner image by passing the recording material through a fusing nip between the fusing roller member and the pressure roller member, includes: an endless belt body constituting an outer peripheral portion of the fusing roller member or the pressure roller member, the endless belt body rotating in a predetermined circumferential path; a pressing member configured to press the fusing nip from the inside of the belt body; a separating member configured to separate the recording material from the belt body; and a tension member abutting on an inside of the belt body for tension, the tension member configured to maintain a gap between the belt body and the separating member.

Fuser and image forming apparatus with an endless belt body and tension member

In a fixing device thermally fixing toner images on recording sheets of various sizes, (i) a conductive heat generating rotational body configured to heat toner images, (ii) an excitation coil positioned along a part of an outer circumferential surface of the heat generating rotational body and configured to generate a magnetic flux to heat the heat generating rotational body by electromagnetic induction, and (iii) a demagnetization coil positioned close to the excitation coil so as to cover a part of the excitation coil and configured to cancel, when a toner image is being fixed on a smaller-sized recording sheet, a part of the magnetic flux generated by the excitation coil so that overheating is prevented in a non sheet-passing region, are provided. The demagnetization coil has a thickness smaller than a thickness of the excitation coil in an axis direction of the coils.

Fixing device and image forming apparatus

A fuser for fixing an unfixed toner image on a recording material includes: an endless belt body heated by a heat source; a pressing body moved to be connected to and disconnected from an inner peripheral surface of the belt body; a pressure roller member making pressure-contact with the pressing body through the belt body; a tension body moved to be connected to and disconnected from the inner peripheral surface of the belt body, contrary to the connection and disconnection movement of the pressing body; and a rotation transmitting unit configured to transmit a rotational force of the pressure roller member to the belt body using the tension body, while the pressing body is separated from and the tension body makes contact with the inner peripheral surface of the belt body.

Fuser and image forming apparatus

A fixing device and an image forming apparatus include, in a fixing nip region, a paper-passage region allowing paper to pass through and a non-paper-passage region located at opposite ends of the paper-passage region and not allowing paper to pass through. The non-paper-passage region is provided with a fixing belt movement restricting member arranged at a prescribed distance away from the fixing belt. Even when the fixing belt comes into abutment with the fixing belt movement restricting member, a prescribed gap is formed between the fixing belt and a surface of the holding member that is opposed to the fixing belt, in the paper-passage region.

Fixing device having gap between fixing belt and fixing roller, and image forming apparatus having fixing device

An induction heating unit enabling to attaching coil on coil attaching surface of bobbin with a high degree of accuracy, and a fixing device capable of maintaining the distance between the coil and the member to be heated at a high degree of accuracy, ensuring uniformity of temperature distribution of the member to be heated, rising temperature at a high speed, and enhancing quality of fixation. In an induction heating unitincluding a magnetizing coilattached on a coil bobbinwhich is disposed outside of annular bodyto be heated, the unit including: a layer of elastic adhesiveprovided on the outer surface of the coil bobbin; a magnetizing coilprovided on the layer of elastic adhesive, the magnetizing coilbeing wound beforehand following an attaching surface; and a layer of elastic adhesiveprovided on the magnetizing coil

Induction heating unit, fixing device and method for attaching coil for induction heating unit

A fixing device has a fixing roller, a pressure roller, an electromagnetic induction heating section, a heat pipe, a temperature sensor and a control section. The fixing roller is heated by the electromagnetic induction heating section. The heat pipe is in contact with the pressure roller. The temperature sensor is in direct contact with the heat pipe to measure temperature of the heat pipe. The control section stops heating of the electromagnetic induction heating section when the temperature of the heat pipe measured by the temperature sensor reaches a preset temperature. This prevents an excessive rise in temperature of the heat pipe and suppresses an excessive increase in internal pressure of the heat pipe. Thereby, the heat pipe in the fixing device is prevented from being damaged.

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Toyokawa, Japan

Hirotaka Kanou