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.

An image forming apparatus includes: a fixing portion for fixing an image formed on a recording material; and a guide member for guiding the recording material. The guide member is provided at an entrance to the fixing portion and at an end portion with respect to a direction perpendicular to a feeding direction of the recording material The guide member is moved when the guide member is pushed by the recording material.

An image forming apparatus includes plural photosensitive members, a scanner unit for scanning the photosensitive members, and a fixing unit for fixing toner images. The scanner unit includes a rotatable polygonal mirror for reflecting laser beams emitted in correspondence to respective photosensitive members, reflecting members for reflecting the laser beams, and a box for accommodating the polygonal mirror and the reflecting members. The box includes plural outlets for the laser beams. Of the reflecting members, first and second reflecting members reflect laser beams toward corresponding first and second outlets respectively positioned farthest from and closest to the fixing unit. A distance between the first outlet and its corresponding photosensitive member is longer than a distance between the second outlet and its corresponding photosensitive member, whereas a distance between the first reflecting member and the polygonal mirror is shorter than a distance between the second reflecting member and the polygonal mirror.

A heating device (9) includes a heater (22), a holder (23), a device frame (40), a primary positioner (A), a secondary positioner (B), and a tertiary positioner (C). The heater includes a heat generator (60). The holder holds the heater. The device frame is configured to support the holder. The primary positioner is configured to position the heater and the holder in a longitudinal direction of the heater. The secondary positioner is configured to position the holder and the device frame in the longitudinal direction of the heater. The tertiary positioner is configured to position the device frame and a body of an image forming apparatus in the longitudinal direction of the heater. The primary positioner and one of the secondary positioner and the tertiary positioner are disposed on an identical side defined by a center of the heat generator in the longitudinal direction of the heater.

An image forming apparatus includes a sheet storage, a sheet feed roller, an image forming device, a fixing device, a motor, a sensor, and a controller having a processor. The sheet storage is configured to store a sheet. The sheet feed roller is configured to feed the sheet stored in the sheet storage into the conveyance path. The image forming device is configured to form an image on the sheet. The fixing device includes a fixing belt and a pressure roller abutting on an outside of the fixing belt, and is configured to fix the image formed on the sheet. The motor is configured to drive and rotate the fixing belt by rotating the pressure roller. The sensor is configured to measure the drive current in the motor. The processor is configured to control a conveyance speed of the sheet based on the measured drive current.

A fixation device includes: a heating roll that heats a transported recording medium whose front end is gripped by a gripping part while rotating; a pressing roll that is disposed so as to face the heating roll, around which at least a part of the transported recording medium is wound, and presses the wound part of the recording medium toward the heating roll while rotating; a peeling part that peels the recording medium off from the pressing roll by lifting the front end of the recording medium up in a state where the front end of the recording medium has passed a portion where the pressing roll and the heating roll face each other and is no longer gripped by the gripping part; and a reducing part that reduces momentum of the peeling part lifting the front end of the recording medium up.

A fixing device includes a rotator, a secured member, a pressure rotator, and lubricant. The rotator has flexibility and a sleeve form. The rotator includes an inner portion having a sliding surface. The inner portion has an elastic power of 55% or more. The secured member is disposed inside a loop of the rotator and has a slide surface on which the sliding surface of the rotator slides. The slide surface has a larger hardness than a hardness of the sliding surface of the rotator. The pressure rotator presses the rotator against the secured member and forms a nip between the rotator and the pressure rotator. The lubricant is provided between the rotator and the secured member.

A pressure device applies pressure to a sheet medium on part of a surface of which an image bearer is formed. The pressure device includes: a driving unit that changes a distance between a first pressing unit and a second pressing unit; a control unit that controls the driving unit such that the distance between the first pressing unit and the second pressing unit becomes a set target value; and a target setting unit that sets the target value to a first distance that is larger than a thickness of the sheet medium when the sheet medium is not present between the first pressing unit and the second pressing unit, and sets the target value to a second distance for applying a target pressure to the sheet medium when the sheet medium and the image bearer are present between the first pressing unit and the second pressing unit.

An image heating apparatus includes a heater having a first heating block and a second heating block, a heating rotating member to be heated by the heater, a pressure rotating member forming a nip portion for conveying a recording material between the pressure rotating member and the heating rotating member, first temperature detection elements and second temperature detection elements for detecting temperatures of the first heating block and second heating block respectively at positions farther from a recording material conveyance reference position than the first temperature detection elements. In the image heating apparatus, the first temperature detection elements are arranged on a side downstream of the heater in a recording material conveying direction, and the second temperature detection elements are arranged on upstream of the first temperature detection elements in the recording material conveying direction.

A fixing unit includes a film including a tubular shape and configured to rotate, a heater arranged inside the film and including a heating resistor configured to generate heat by passing alternating current therethrough and an insulator configured to cover the heating resistor, a sliding member arranged between the heater and the film and configured to be in sliding contact with an inner surface of the film, the sliding member having electric conductivity, a pressing member configured to be in pressure contact with the sliding member across the film to form a nip portion between the sliding member and the pressing member, and a conductive member electrically connected to a ground potential via at least one impedance element. The sliding member is electrically connected to the conductive member.