An object of the invention is to provide a fixation member which has an unfixed toner fixation function and ensures high releasability, low chargeability, and high friction. The fixation member has an elastic layer, and a release layer on the external surface of the elastic layer, wherein the release layer is formed of a fluororesin tube having low chargeability and a percent dielectric relaxation of 15% or higher.

A fixing device includes a fixing belt, a pressuring roller pressured to the fixing belt, a heat source heating the fixing belt, a pressing member pressing the fixing belt toward the pressuring roller's side, and a sliding contact sheet interposed between the fixing belt and the pressing member to hold lubricant. The sliding contact sheet includes a sliding contact portion arranged at the center in a sheet conveying direction to come into contact with the fixing belt, a first fixed portion arranged at an upstream side in the conveying direction and wound around the pressing member at the heat source's side, and a second fixed portion arranged at a downstream side in the conveying direction and wound around the pressing member at the heat source's side from the first fixed portion. The sliding contact sheet is configured so that the second fixed portion becomes smaller than the first fixed portion.

A transfer belt transfers a toner image carried on a first main surface to a recording medium. When the transfer belt is pressed by using a lower block provided with a hole and an upper block with pressurization force increased at a prescribed rate and thereafter kept constant, E [-] and t0 are curve-fitted to a function E=exp(t0/) defined by a time constant [s] with respect to an amount of displacement of the transfer belt and a constant [-], where E [-] is calculated as (ab)/b, a [m] represents a maximum value of an amount of displacement of a measurement region, b [m] represents an amount of displacement of the measurement region after converged, and t0 [s] represents a time period from start of pressurization until the maximum pressurization force, and time constant satisfies a condition of 0.0150.1.

An imaging device having a fuser and print engine architecture that enables complete interchangeability between fuser types with a common print engine. The imaging device has a frame configured to separately receive a first fuser assembly of a first fuser type and a second fuser assembly of a second fuser type different from the first fuser type. The first fuser assembly includes a first fuser frame having a first datum tab. The second fuser assembly includes a second fuser frame having a second datum tab. The frame of the imaging device has a datum aperture that is sized to receive the first datum tab that when inserted into the datum aperture, causes the first fuser assembly to be positioned at a first operative position, and the second datum tab that when inserted into the datum aperture, causes the second fuser assembly to be positioned at a second operative position.

In a rotating device, a pair of cuts are formed in an end portion of a metal-made cylindrical body to which a pressure is applied, at positions that face in a diameter direction. A support portion of a synthetic-resin-made bush rotatably supports the cylindrical body. In a state where a center of the cylindrical body matches a rotation center line of the bush, and a first diameter direction connecting respective centers in a circumferential direction of the cuts matches a second diameter direction connecting centers in the circumferential direction of a pair of engaging portions, each interval in the circumferential direction between the engaging portions and edge portions of the cuts is equal to or larger than an interval in a direction perpendicular to the rotation center line between an outer circumferential surface of the support portion and an inner circumferential surface of the end portion.

A transfer belt transfers a toner image carried on a first main surface to a recording medium. When the transfer belt is pressed by using a lower block provided with a hole and an upper block with pressurization force increased at a prescribed rate and thereafter kept constant, E [-] and t0 are curve-fitted to a function E=exp(t0/) defined by a time constant [s] with respect to an amount of displacement of the transfer belt and a constant [-], where E [-] is calculated as (ab)/b, a [m] represents a maximum value of an amount of displacement of a measurement region, b [m] represents an amount of displacement of the measurement region after converged, and t0 [s] represents a time period from start of pressurization until the maximum pressurization force, and time constant satisfies a condition of 0.0150.1.

A fixing device includes a first unit and a second unit. The first unit includes: a first belt being movable in a first direction; a first pressing member pressing the first belt; and a first pressing member support supporting the first pressing member. The second unit includes a moving member and faces the first unit in a second direction. The moving member is able to come into contact with the first belt and movable in the first direction. The first pressing member is supported, by the first pressing member support, variably in attitude of the first pressing member relative to the first pressing member support.

A fixing device includes a fixing belt, a pressuring roller pressured to the fixing belt, a heat source heating the fixing belt, a pressing member pressing the fixing belt toward the pressuring roller's side, and a sliding contact sheet interposed between the fixing belt and the pressing member to hold lubricant. The sliding contact sheet includes a sliding contact portion arranged at the center in a sheet conveying direction to come into contact with the fixing belt, a first fixed portion arranged at an upstream side in the conveying direction and wound around the pressing member at the heat source's side, and a second fixed portion arranged at a downstream side in the conveying direction and wound around the pressing member at the heat source's side from the first fixed portion. The sliding contact sheet is configured so that the second fixed portion becomes smaller than the first fixed portion.

An imaging device having a fuser and print engine architecture that enables complete interchangeability between fuser types with a common print engine. The imaging device has a frame configured to separately receive a first fuser assembly of a first fuser type and a second fuser assembly of a second fuser type different from the first fuser type. The first fuser assembly includes a first fuser frame having a first datum tab. The second fuser assembly includes a second fuser frame having a second datum tab. The frame of the imaging device has a datum aperture that is sized to receive the first datum tab that when inserted into the datum aperture, causes the first fuser assembly to be positioned at a first operative position, and the second datum tab that when inserted into the datum aperture, causes the second fuser assembly to be positioned at a second operative position.

A fixing device includes a rotatably-supported first fixing member and a second fixing member pressed against the first member. The second member includes a belt-shaped component, a support component, and a pressing component. The belt-shaped component extends in a width direction of a medium passing through a contact region between the belt-shaped component and the first member. The support component is disposed opposite the first member with the belt-shaped component interposed therebetween. The pressing component has a base end supported by the support component and a free end extending toward the contact region and presses the belt-shaped component against the first member. The pressing component has biasing portions arranged apart in the width direction and elastically deformable in correspondence with the medium thickness. The biasing portions are connected in the width direction by the free end. The free end is disposed at an upstream side in a medium transport direction.