A snap ring is set to a set portion of a shaft of a rotator from a direction orthogonal to an axial direction of the shaft. The snap ring includes a first arcuate portion and a second arcuate portion facing each other, being elastically deformable in directions away from each other, holding the set portion by elastic deformation restoring force. One ends of the first and second arcuate portions are away from each other to form an insertion portion to insert the set portion. When the snap ring is not used, the first arcuate portion has a same radius of curvature as the second arcuate portion and the set portion, and a center of curvature closer to the second arcuate portion than the first arcuate portion, and the second arcuate portion has a center of curvature closer to the first arcuate portion than the second arcuate portion.

A pair of pressure members are disposed at both ends of a pressure roller and rotatably support the pressure roller to press the pressure roller against a fixing roller including an elastic layer via a fixing belt. One of the pressure members that includes a fulcrum engaging section engaged with a rotation fulcrum at one end and is locked to a biasing member at a side opposite to the fulcrum engaging section is moved by a moving member in a direction intersecting a pressing direction of the pressure roller in a state where deformation of the elastic layer is regulated. Thus, a force acting on a fixing nip formed by the deformation of the elastic layer of the fixing roller is stabilized. As a result, the traveling performance of the fixing belt is stabilized, whereby the offset control can be performed with high accuracy.

An image forming apparatus includes a fixing unit, an image forming unit, and a controller. The controller is configured to receive image data corresponding to a target image to be formed on a sheet, convert the received image data to modified image data corresponding to a modified image that includes the target image and an added margin on at least one side of the target image in a sheet width direction side, control the image forming unit to form the modified image based on the modified image data, and cause the sheet to be conveyed to the image forming unit such that a positioning of the sheet in the sheet width direction overlaps with the target so that a fixing portion of the fixing unit overlaps with the target image in the modified image formed on the sheet.

A fuser assembly includes a heated member and backup member forming a fusing nip. Nip loading springs on either ends of the fusing nip bias into contact the backup member and the heated member. Bellcranks contact the nip loading springs. Rotatable latches on either ends of the fusing nip act on the bellcranks to compress or relax the nip loading springs to open or close the fusing nip at respective distal or proximate ends of the fuser assembly. The rotatable latches are acted upon by corresponding latches of an access door of an imaging device that when opened provides access to the fuser assembly in an interior of the imaging device. The rotatable latches are independently movable. They can reside in different positions, yet allow closing the door of the imaging device.

A protruding portion protruding in a rotation axis direction of an image bearing member is provided at a position between the tip of a separation claw and an apex of the separation claw, when the apex of the separation claw is disposed at a position farthest from the surface of the image bearing member in a direction perpendicular to a straight line connecting the tip and the rotation center of a shaft portion of the separation claw.

An image forming apparatus includes an image forming unit, a storage portion to which a heating unit configured to heat the sheet stored in the storage portion is detachably attached, a conveyance unit, a detection unit configured to detect attachment of the heating unit to the storage portion, and a control unit configured to control the conveyance unit such that a standby time by which conveyance of the sheet fed from the storage portion is stopped is shorter when the detection unit detects the heating unit than when the detection unit does not detect the heating unit.

A fixing device includes first and second rotatable members; a movable member; a first supporting side plate including an opening; a second supporting side plate; a detecting portion; a supporting plate; a holding portion; a slit portion; a first projected portion; a second projected portion; and a hole. When the position of the holding portion with respect to the height direction is regulated by the second projected portion in contact with the supporting plate, in a projection plane in which the outside of the first supporting side plate is viewed in the longitudinal direction of the first rotatable member, the flag portion is accommodated inside the opening and is in a non-overlapping position with the detecting portion. When the projected portion is engaged in the hole, in the projection plane, the flag portion is in an overlapping position with the detecting portion.

A pair of pressure members are disposed at both ends of a pressure roller and rotatably support the pressure roller to press the pressure roller against a fixing roller including an elastic layer via a fixing belt. One of the pressure members that includes a fulcrum engaging section engaged with a rotation fulcrum at one end and is locked to a biasing member at a side opposite to the fulcrum engaging section is moved by a moving member in a direction intersecting a pressing direction of the pressure roller in a state where deformation of the elastic layer is regulated. Thus, a force acting on a fixing nip formed by the deformation of the elastic layer of the fixing roller is stabilized. As a result, the traveling performance of the fixing belt is stabilized, whereby the offset control can be performed with high accuracy.

An image forming apparatus includes: a belt unit including a transfer belt and a first memory that stores a first sheet conveying speed of the transfer belt; a second memory storing a first reference value and a second sheet conveying speed of the fixing unit a controller configured to: control at least one of the belt motor and the fixing motor to bring the speed difference between the sheet conveying speed of the transfer belt and the sheet conveying speed of the fixing unit closer to the first reference value by setting a rotational speed of the fixing motor based on the first reference value and a first speed difference between the first sheet conveying speed read from the first memory and the second sheet conveying speed read from the second memory.

A cylinder member includes: a cylinder body having a cross section and including a dent portion; a sheet member wrapped around the cylinder body and including a metal layer contacting the cylinder body and an outer layer; a first attachment member on a sheet member first end portion and removably attached to the dent portion; a second attachment member on a metal layer end portion protruding from the outer layer in the circumferential direction at a sheet member second end portion, the second attachment member being removably attached to the dent portion; a tension-applying mechanism pulling the second attachment member in a dent portion depth direction to apply tension to the metal layer; a projection on one of the second attachment member and metal layer end portion; and a fitting portion on other one of the second attachment member and the metal layer end portion and fitted to the projection.