A roller used in a fixing device includes a rubber layer including a plurality of void portions, pore passage portions connecting the void portions, and a filler, wherein an aspect ratio RA of the filler is 2.5≤RA≤215, and a linear expansion coefficient of the rubber layer is less than or equal to 400×10.sup.−6/K.

A fixing device includes a belt member, a fixing member facing an outer peripheral surface of the belt member and forming a fixing nip portion between the belt member, and a separating pad portion disposed inside the belt member, including a pressing surface for pressing the fixing member at downstream of the fixing nip portion in a moving direction of the belt member and separating a recording material from the fixing member. The pressing surface of the separating pad portion curves so as to protrude toward the fixing member as approaching a central portion thereof in a rotation axis direction of the fixing member. An upstream end portion and a downstream end portion of the pressing surface curve so as to protrude toward an upstream side in the moving direction as they approach the central portion in the rotation axis direction.

A pressing device includes a rotator, a secured member, a pressure rotator, and lubricant. The rotator has flexibility and a sleeve form and includes an inner portion having a sliding surface. The inner portion has an elastic power of 55% or more. The secured member is inside a loop of the rotator and has a slide surface on which the sliding surface of the rotator is to slide. The slide surface has a smaller surface roughness than a surface roughness of the sliding surface. The pressure rotator presses the rotator against the secured member and forms a nip between the rotator and the pressure rotator. The lubricant between the rotator and the secured member has a consistency of 275 or less.

A member for a fuser assembly of a printer. The member may include a support body and a composite coating disposed on an outer surface of the support body. The composite coating may include a fluororesin and a nanocarbon material dispersed within the fluororesin. The nanocarbon material may be present in a higher concentration proximate the support body and a lower concentration proximate an outer surface of the composite coating. The lower concentration may be less than or equal to about 2 wt % of the nanocarbon material.

A device includes a rotator having a rotation axis, a belt, a nip forming member surrounded by the belt, a first stay surrounded by the belt and extending in a width direction parallel to the rotation axis, a holder holding the nip forming member, and an urging member urging the first stay toward the rotator. The nip forming member is configured to, with the rotator, pinch the belt to form a nip. The first stay includes a first end and a second end. The holder includes a first engaging portion positioned at a first end of the holder, and a second engaging portion positioned at a second end of the holder. The first engaging portion engages the first end of the first stay. The second engaging portion engages the second end of the first stay.

The roller for use in a fixing device, includes a metal core, a first elastic layer formed on an outer side of the metal core, the first elastic layer having voids, and a second elastic layer formed on an outer side of the first elastic layer, the second elastic layer having a microhardness higher than a microhardness of the first elastic layer, in which an outer diameter of an end portion of the roller is larger than an outer diameter of a middle portion of the roller in a longitudinal direction of the roller, and in which the microhardness of the second elastic layer is 25 degrees or more and 50 degrees or less.

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 separator is disposed downstream from the nip former in a recording medium conveyance direction and stretches the fixing belt. The separator is spaced apart from the pressure rotator via the fixing belt. A presser is interposed between an exit of the fixing nip and an upstream end of the separator in the rotation direction of the fixing belt. The presser comes into contact with an inner circumferential surface of the fixing belt to press the fixing belt against the pressure rotator.

A fixing device includes a pressuring member, a fixing frame, a pressuring frame, a pressure changing part, a rotation detecting part and a rotation transmitting part. The pressuring member forms a fixing nip with a fixing member. The fixing frame supports the fixing member. The pressuring frame supports the pressuring member. The pressure changing part changes fixing nip pressure. The rotation transmitting part transmits rotation of the pressuring member to the rotation detecting part. The fixing frame is turnably supported around a fulcrum part provided on the pressuring frame. The pressure changing part turns the fixing frame around the fulcrum part. The rotation transmitting part has a first rotating body and a second rotating body. The first rotating body is provided on a rotation shaft of the pressuring member. The second rotating body is engaged with the first rotating body and rotatably supported around the fulcrum part.

An image forming apparatus includes: a transfer unit configured to transfer a toner image to a recording medium at a transfer nip; a fuser unit configured to heat and pressurize at a fuser nip the recording medium to which the toner image has been transferred by the transfer unit, to fuse the toner image to the recording medium; and a pressing unit configured to press both edge portions of the recording medium in a width direction between the transfer nip and the fuser nip so that a central portion of the recording medium in the width direction becomes lower than the both edge portions of the recording medium in the width direction.

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.