Fixing device including heating span adjuster, image forming apparatus, and fixing method

摘要

A fixing device includes a fixing rotator heated by a heater and a pressing rotator to press against the fixing rotator to form a fixing nip therebetween. A heating span adjuster, interposed between the heater and the fixing rotator, is movable in a circumferential direction of the fixing rotator. The heating span adjuster moves to a retracted position where the heating span adjuster allows the heater to heat the fixing rotator in an increased axial heating span of the fixing rotator after the heater starts heating the fixing rotator until the fixing rotator and the pressing rotator start conveying a recording medium through the fixing nip. The heating span adjuster at the retracted position is outboard from a circumferential, direct heating span of the fixing rotator where the heater heats the fixing rotator directly.

主权项

1. A fixing device comprising:
a fixing rotator rotatable in a predetermined direction of rotation; a heater disposed opposite the fixing rotator to heat the fixing rotator; a pressing rotator to press against the fixing rotator to form a fixing nip therebetween, the fixing nip through which a recording medium is conveyed; and a heating span adjuster interposed between the heater and the fixing rotator and movable in a circumferential direction of the fixing rotator to change an axial heating span of the fixing rotator where the heater heats the fixing rotator, the heating span adjuster to move to a retracted position where the heating span adjuster allows the heater to heat the fixing rotator in an increased axial heating span of the fixing rotator after the heater starts heating the fixing rotator until the fixing rotator and the pressing rotator start conveying the recording medium through the fixing nip, the retracted position where the heating span adjuster is outboard from a circumferential, direct heating span of the fixing rotator where the heater heats the fixing rotator directly.