A control unit is configured to control torque of a fixing motor and torque of a pressing motor such that tangential force at a part holding paper in cooperation with a fixing member in a pressing member is equal to or greater than tangential force at a part holding paper in cooperation with the pressing member in the fixing member, and that the relation between the tangential force at the part of the pressing member and the tangential force at the part of the fixing member changes in accordance with the smoothness of paper.

A fixing device includes a fixing belt looped over a first roller and a second roller and rotatable in a predetermined direction of rotation and a pressure rotator to press against the first roller via the fixing belt to form a fixing nip between the fixing belt and the pressure rotator. A separation aid, disposed downstream from the fixing nip in the direction of rotation of the fixing belt, contacts an inner circumferential surface of the fixing belt to decrease a radius of curvature of the fixing belt. A polishing roller, disposed downstream from the separation aid and upstream from the second roller in the direction of rotation of the fixing belt, contacts an outer circumferential surface of the fixing belt. An opposed roller, disposed opposite the polishing roller via the fixing belt, forms a polishing nip between the polishing roller and the fixing belt.

An image forming apparatus includes a heating device including a rotator member, a heating member configured to heat the rotator member. The heating member is switchable between a first heat generation state in which an amount of heat generated on a first side is larger than an amount of heat generated on a second side in the intersection direction and a second heat generation state in which the amount of heat generated on the second side is larger than the amount of heat generated on the first side, The image forming apparatus is configured to switch between the first heat generation state and the second heat generation state while executing a job of continuously forming an image on a plurality of recording media having a same length in the intersecting direction.

A fixing device includes: a fixing belt; a facing member disposed on an inner side of the fixing belt; a pressure roller that presses against the fixing belt toward the facing member from outside to form a fixing nip area; a heat source; a non-passage area temperature measurer that measures a temperature of a sheet non-passage area; a pressure roller swinger that swings one end side of the pressure roller in a direction intersecting with a longitudinal direction of the fixing nip area; and a controller that performs meandering correction control for correcting a movement direction of the fixing belt by causing the pressure roller swinger to swing the pressure roller, and the controller has such a movement mode as to cause the pressure roller swinger to forcibly move the fixing belt in a direction away from the non-passage area temperature measurer while rotating the fixing belt.

An image forming apparatus having a fixing unit, a belt, a conveyance unit, a heat sink, first and second rollers, a belt position detection unit, a steering unit, and a control unit further includes an image forming unit to form a toner image on a recording material, and perform a state transition to a power-off state and to a standby state where image forming by the image forming unit is possible. The belt position detection unit detects a position of the belt. The steering unit swings the first roller relative to the second roller based on a detection result by the belt position detection unit to widthwisely move the belt relative to the first roller. When the image forming apparatus enters the power-off state, the control unit controls the steering unit to make a rotational axis of the first roller approximately parallel to a rotational axis of the second roller.

Provided is a fixing belt wherein a base layer made of heat-resistant resin, an elastic layer made of an elastic material, and a release layer are laminated in this order, and the elastic layer has a linear thermal expansion coefficient of −4.0×10.sup.−4 (1/K) or more and 1.0×10.sup.−4 (1/K) or less.

A fixing device includes a fixing belt that is endless and rotatable in a rotation direction and a nip former stretching the fixing belt. A pressure rotator presses against the nip former via the fixing belt to form a fixing nip between the fixing belt and the pressure rotator, through which a recording medium is conveyed. A separator is disposed downstream from the nip former in a recording medium conveyance direction and stretches the fixing belt. The separator is spaced apart from the pressure rotator via the fixing belt. A presser is interposed between an exit of the fixing nip and an upstream end of the separator in the rotation direction of the fixing belt. The presser comes into contact with an inner circumferential surface of the fixing belt to press the fixing belt against the pressure rotator.

A fixing device includes a pair of fixing members disposed to face each other in a fixing area, a movable member movably supporting at least one of the fixing members between first and second positions, a driving device including a contact member and a drive source to move the movable member between the first and second positions, and a controller that controls the driving device, and if a temperature of the one of the fixing members is equal to or higher than a preset temperature when the driving device moves the movable member from the second position to the first position, changes the control to make driving force constantly exceed a rotational load of the driving device in accordance with advancement of a time of increase in the rotational load as compared with when the temperature of the one of the fixing members is lower than the preset temperature.

A fixing device includes a fixing belt that is endless and rotatable in a rotation direction and a nip former stretching the fixing belt. A pressure rotator presses against the nip former via the fixing belt to form a fixing nip between the fixing belt and the pressure rotator, through which a recording medium is conveyed. A presser is disposed downstream from an exit of the fixing nip in a recording medium conveyance direction. The presser brings the fixing belt into contact with the pressure rotator. A gap retainer contacts the nip former and is coupled to the presser to retain isolation of the presser from the nip former.

A fixing device includes a fixing belt that is endless and rotatable in a rotation direction and a nip former stretching the fixing belt and including an elastic layer as a surface layer. A pressure rotator presses against the nip former via the fixing belt to form a fixing nip between the fixing belt and the pressure rotator, through which a recording medium is conveyed. A presser is disposed downstream from an exit of the fixing nip in a recording medium conveyance direction. The presser brings the fixing belt into contact with the pressure rotator.