An image heating apparatus includes an endless belt for heating a toner image on a sheet; a first detector for detecting a temperature of one longitudinal end portion of the endless belt; a second detector for detecting a temperature of the other longitudinal end portion of the endless belt; and a controller for controlling whether or not notification of generation of an error is provided on the basis of a change amount per unit time of a difference in detection temperature between the first detector and the second detector.

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.

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 the rotation direction of the fixing belt. The presser brings the fixing belt into contact with the pressure rotator. A mover is coupled to the presser to move the presser between a contact position where the presser brings the fixing belt into contact with the pressure rotator and an isolation position where the presser isolates the fixing belt from the pressure rotator.

An image forming apparatus includes an image forming portion configured to form a developer image on a recording material, a fixing portion configured to heat-fix the developer image to the recording material, a first motor configured to drive the image forming portion, a second motor configured to drive the fixing portion, and a control portion configured to control the first motor and the second motor. The second motor is a stepping motor. The control portion allows the second motor to start rotation at a speed in a self-start region, temporarily stops the second motor at a timing at which the first motor is activated, then allows the second motor to restart rotation at a speed in the self-start region, and changes the speed of the second motor to a speed outside of the self-start region before the recording material arrives at the fixing portion.

In accordance with an embodiment, a fixing device comprises a first rotating body; a second rotating body configured to face the first rotating body and be stretched over a plurality of rotating bodies; and a first mechanism configured to enable at least one among a plurality of the rotating bodies to move to change a nip width between the first rotating body and the second rotating body.

An image forming apparatus includes a heating unit that heats a recording material, a contact member that is positioned upstream or downstream from the heating unit in a transport direction of the recording material and is in contact with the recording material, the contact member being configured in such a manner that a portion of the contact member that is in contact with the recording material moves with the recording material, a temperature detection unit that detects a temperature of the contact member, and a control unit that controls, based on a detection result obtained by the temperature detection unit, an output of the heating unit.

According to one embodiment, an image forming apparatus includes a printer device, a fixing device, an input interface, and a controller. The controller executes a temperature-change process where the controller determines that it is necessary to change the target temperature of the fixing device on the basis of the image-forming instruction input from the input interface, the temperature-change process including changing the target temperature of the fixing device to a new target temperature. Further, the controller controls the printer device to start an image-forming process on the basis of the image-forming instruction after the temperature-change process.

A fixing device includes a heating belt, a heat source, a pressuring body, a pressing member and a sheet member. The heating belt is endless and heats a medium while being circulated. The heat source supplies heat to the heating belt. The pressuring body forms a nip with the heating belt, rotates so as to circulate the heating belt and presses the medium with the heating belt. The pressing member is disposed inside the heating belt and presses the heating belt against the pressuring body at the nip. The sheet member is held between the heating belt and the pressing member, attached to the pressing member at a center side portion and both end side portions in a longitudinal direction of the sheet member and has a heat shrinkable property. The both end side portions are shiftable in the longitudinal direction greater than the center side portion.

In accordance with an embodiment, a fixing device comprises a first rotating body; a second rotating body configured to face the first rotating body and be stretched over a plurality of rotating bodies; and a first mechanism configured to enable at least one among a plurality of the rotating bodies to move to change a nip width between the first rotating body and the second rotating body.