According to one embodiment, an image forming apparatus includes a sheet supply unit, a printer, a fixing device, and a controller. The sheet supply unit supplies a sheet from a sheet container. The printer forms a toner image to the sheet conveyed from the sheet supply unit. The fixing device includes a heater, a fixing belt, and a pressure roller. The heater includes a heat generating member including a plurality of heating elements arranged in a first direction orthogonal to a sheet conveyance direction and in which a heating element group selected in response to a printing request from the heat generating member generates heat. The fixing belt fixes the toner image heated by the heater to the sheet. The pressure roller presses the fixing belt.

A fixing apparatus including: a first rotary member; a second rotary member; a nip forming member; and a heater. The nip forming member includes: a first projection portion inside a nip area; and a second projection portion located outside the nip area. The first and second projection portion abut against the inner circumferential surface of the first rotary member. In a direction orthogonal to a nip tangent, a distance between a tip of the second projection portion and the nip tangent is larger than a distance between a tip of the first projection portion and the nip tangent. The second projection portion extends toward the second rotary member without exceeding the nip tangent. A radius of curvature at a tip portion of the second projection portion is smaller than a radius of an inner circumferential circle of the first rotary member.

A fixing apparatus including: a first rotary member; a second rotary member; a nip forming member; and a heater. The nip forming member includes: a first projection portion inside a nip area; and a second projection portion located outside the nip area. The first and second projection portion abut against the inner circumferential surface of the first rotary member. In a direction orthogonal to a nip tangent, a distance between a tip of the second projection portion and the nip tangent is larger than a distance between a tip of the first projection portion and the nip tangent. The second projection portion extends toward the second rotary member without exceeding the nip tangent. A radius of curvature at a tip portion of the second projection portion is smaller than a radius of an inner circumferential circle of the first rotary member.

A fixing apparatus includes an endless first rotary member, a second rotary member configured to form a nip portion, and a nip member configured to be rubbed against the first rotary member via lubricant, and being configured to receive radiant heat from a heating element and heat the nip portion. The nip member involves a nip forming portion configured to be in contact with the first rotary member, and an extending portion formed continuously with a downstream edge portion of the nip forming portion. The extending portion involves a holding portion configured to hold the lubricant. The holding portion is longer than the second rotary member and shorter than the first rotary member, and when viewed in a sheet conveyance direction, both end portions of the holding portion are position outside of end portions of the second rotary member and inside of end portions of the first rotary member.

A fixing device including: a heating rotating body; a pressure member pressed against the heating rotating body to form a nip; a first acquisition unit that acquires a first index value indicating a change in coefficient of friction between the heating rotating body and the pressure member; a second acquisition unit that acquires a second index value indicating a change in rigidity of an elastic layer in the heating rotating body and/or the pressure member; and a controller that executes at least one of two controls according to the index values: a first control during idling rotation after fixing job execution, for controlling temperature of the heating rotating body and time from a start of the idling rotation to an end of the idling rotation and a second control during idling rotation before and/or after fixing job execution, for controlling rotation speed of the heating rotating body.

There is provided a guide incorporated in a fixing device including a belt configured to circularly move in a moving direction. The guide includes: a guide portion elongated in a longitudinal direction orthogonal to the moving direction; a first gate mark; and a second gate mark arranged spaced apart from the first gate mark in the longitudinal direction. The guide portion includes a resin and a plurality of elongated-shaped fillers dispersed in the resin. The guide portion has a guide surface configured to guide movement of the belt in the moving direction, a peripheral surface of the belt being configured to contact the guide surface.

A fixing device includes a first belt that contacts a developer image on a recording medium; a second belt that sandwiches the recording medium with the first belt and hence forms a nip region extending in a transport direction of the recording medium; a rotational body that is provided inside the first belt in a region at a downstream side in the transport direction of the nip region, rotates, and turns the first belt; a pressing member that is provided inside the second belt and presses the second belt toward the rotational body; and a heating unit that is provided inside the first belt in a region at an upstream side in the transport direction of the nip region in a non-contact manner with respect to the first belt, and heats the developer image on the recording medium.

A fuser configured to nip a sheet by a heating member and a pressurizing member and to thermally fix an image formed in a toner on the sheet, is provided. The fuser includes a supporting member, a temperature sensor, and a sensor cover. The supporting member supports the heating member. The temperature sensor is attached to the supporting member and is configured to detect a temperature of the heating member without contacting the heating member. The sensor cover is located on a side of the temperature sensor opposite to the heating member to cover the temperature sensor. The sensor cover includes a base having an opening at an upper position with respect to the temperature sensor and a windshield wall located in adjacent to the base. The windshield wall protrudes upward and extends in a lengthwise direction for the heating member.

An image forming apparatus includes a heating rotary member, a pressure rotary member, a nip portion formed by the rotary members, a temperature adjustment control section controlling a temperature of the heating rotary member to a target temperature, a cleaning web removing toner adhering to the heating rotary member, and a controller selectively executing one of a cleaning mode and a non-cleaning mode. A first basis weight and a second basis weight greater than the first predetermined basis weight are set, in a job that mixedly uses recording media with the first and second basis weights. When the controller executes the non-cleaning mode, the temperature adjustment control section sets a target temperature of a recording medium with a basis weight less than or equal to the first basis weight to a temperature lower than a target temperature of the recording medium in the cleaning mode.

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.