A fixing device includes an endless belt and a pressure rotator disposed opposite an outer circumferential surface of the endless belt. The pressure rotator has a first span in an axial direction of the endless belt. A nip formation pad, which is disposed opposite an inner circumferential surface of the endless belt, forms a fixing nip between the endless belt and the pressure rotator. The nip formation pad includes a belt-side face disposed opposite the endless belt. A radiant heater, which is disposed opposite the inner circumferential surface of the endless belt, heats the endless belt. A thermal conduction aid, which contacts the belt-side face of the nip formation pad, conducts heat in the axial direction of the endless belt. The thermal conduction aid has a second span within which the first span of the pressure rotator is provided at the fixing nip.

A fixation device includes: an endless belt member; a first roller arranged inside the belt member; a second roller arranged outside the belt member and biased toward the first roller via the belt member; and a pressure member is biased toward the second roller via the belt member. A facing surface of the pressure member that faces the second roller includes a first flat section and a second flat section that intersect at an intersecting portion. A first end portion of the first flat section on the opposite side to the intersecting portion, a second end portion of the second flat section on the opposite side to the intersecting portion, and the intersecting portion are on an imaginary arc in a cross-section. A radius R of the imaginary arc satisfies, with respect a radius Rp of the second roller, an inequality of (1/2)RpR(19/20)Rp.

A fixing apparatus includes: first and second pressure members each of which is in contact with an inner circumferential surface of an endless belt and nips the endless belt between itself and a cylindrical member; a frame supporting the first and second pressure members; an actuator that moves the first pressure member between a first position and a second position in a movement direction of a portion, of the endless belt, positioned between the first and second pressure members; and an elastic body that generates nipping force to nip the endless belt. The nipping force by the elastic body is generated between the cylindrical member and the first and second pressure members, both in a case that the first pressure member is positioned in the first position and a case that the first pressure member is positioned in the second position.

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 fixation device includes: an endless belt member; a first roller arranged inside the belt member; a second roller arranged outside the belt member and biased toward the first roller via the belt member; and a pressure member is biased toward the second roller via the belt member. A facing surface of the pressure member that faces the second roller includes a first flat section and a second flat section that intersect at an intersecting portion. A first end portion of the first flat section on the opposite side to the intersecting portion, a second end portion of the second flat section on the opposite side to the intersecting portion, and the intersecting portion are on an imaginary arc in a cross-section. A radius R of the imaginary arc satisfies, with respect a radius Rp of the second roller, an inequality of (1/2)RpR(19/20)Rp.

A fixing portion is provided with a fixing roller, a heating roller having a heat source, a fixing belt stretched between the fixing roller and the heating roller, and a pressurizing roller that is brought into pressure contact with the fixing roller across the fixing belt and forms a nip portion into which a sheet of paper is conveyed between the fixing belt and the pressurizing roller. The fixing portion is further provided with a pad that has a contact surface portion in contact with the inner peripheral surface of the fixing belt, and a biasing member that biases the pad in a direction in which the contact surface portion is brought into pressure contact with the inner peripheral surface of the fixing belt. The pad is configured so as to pivot about the rotating shaft of the heating roller.

A fixing device includes an endless fixing belt stretched taut across a first roller and a second roller and rotatable in a predetermined direction of rotation. A pressure rotator is pressed against the first roller via the fixing belt to form a fixing nip between the pressure rotator and the fixing belt, through which a recording medium is conveyed. A separation aid, disposed downstream from the fixing nip in the direction of rotation of the fixing belt to separate the recording medium from the fixing belt, includes a contact face contacting an inner circumferential surface of the fixing belt and a bulge disposed at a center of the contact face in a longitudinal direction of the separation aid. The bulge projects toward the inner circumferential surface of the fixing belt relative to each lateral end of the contact face in the longitudinal direction of the separation aid.

A heater unit includes a heater in which a heating resistor member and an electrode electrically connected to the heating resistor member are disposed on a board; a connector having a connection terminal and attached to the heater at a specific connector attaching position thereof for electrically connecting the connection terminal to the electrode; a heater side engaging portion disposed on the heater; and a connector side engaging portion for engaging with the heater side engaging portion. The heater side engaging portion is provided for restricting the connector attached to the heater at the specific connector attaching position from shifting relative to the specific connector attaching position.

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 fixing member which ensures a surface pressure during toner fixation and which can achieve both an enhanced grip force of an elastic layer and cost efficiency; and a method for producing the fixing member are provided. The fixing member, as a press roll, has the elastic layer of a foamed elastic material on the outer peripheral surface of a core body. The elastic layer is an integrally shaped product of the foamed elastic material. When the specific gravity of the foamed elastic material in axially opposite end portions (grip portions) of the elastic layer is designated as d.sub.1, the specific gravity of the foamed elastic material in a portion (free portion) of the elastic layer other than the grip portions is designated as d.sub.2, and the specific gravity d.sub.2 is 0.7 or less, the proportion of the difference between d.sub.1 and d.sub.2 to the specific gravity d.sub.2 is 10-70%.