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 device includes a pair of fixing members disposed to face each other in a fixing area, a movable member movably supporting at least one of the fixing members between first and second positions, a driving device including a contact member and a drive source to move the movable member between the first and second positions, and a controller that controls the driving device, and if a temperature of the one of the fixing members is equal to or higher than a preset temperature when the driving device moves the movable member from the second position to the first position, changes the control to make driving force constantly exceed a rotational load of the driving device in accordance with advancement of a time of increase in the rotational load as compared with when the temperature of the one of the fixing members is lower than the preset temperature.

According to an aspect of the invention, a fixing member includes a base material; an elastic layer that is provided on the base material and is made from a cured material of a silicone rubber composition containing a heat active catalyst and an ultraviolet ray active catalyst; and a surface layer provided on the elastic layer.

A fixing member includes a base material, an elastic layer that is provided on the base material, and contains a cured material of a composition including thermosetting type silicone rubber, an adhesion layer that is provided on the elastic layer, and contains a cured material of a composition including an ultraviolet ray curing type silicone rubber and a surface layer provided on the adhesion layer.

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.

An endless belt includes a base material layer containing a polymer material and conductive particles, wherein, in an image obtained by observing a cross section taken along a thickness direction of the base material layer with an atomic force microscope, a proportion of a total area Ap of cross sections of all the conductive particles is 9.0% or more and 14.5% or less with respect to a total cross-sectional area At of the base material layer, and a proportion of a total area Ab of cross sections of conductive particles having an area of 0.01 .Math.m.sup.2 or more among cross sections of the conductive particles is 28.0% or more and 65.0% or less with respect to the total area Ap of cross sections of all the conductive particles.

In a fixing device, a first fixing member and a second fixing member are configured to form a nip in combination, and an arm biased by a first spring with a first biasing force provides a nip pressure. A cam rotatably arranged to cause the arm to move against the first biasing force has a first cam surface used to change the nip pressure from a first pressure to a second pressure smaller than the first pressure, and a second cam surface of which an angle of action is greater than that of the first cam surface to change the nip pressure from the second pressure to a third pressure smaller than the second pressure. A maximum pressure angle at the second cam surface is smaller than a maximum pressure angle at the first cam surface.

A pressing device includes a first pressurization unit; a second pressurization unit that is provided to face the first pressurization unit, and sandwiches and pressurizes a medium moving in a contact region formed between the first pressurization unit and the second pressurization unit; and a contact region variable unit that changes a width dimension of the contact region along a moving direction of the medium in a state of maintaining a contact pressure on an outlet side of the contact region, in varying a contact state of the contact region.

A heating device includes a rotator, an opposed rotator configured to contact the rotator to form a nip, a heater configured to heat the rotator, and a plurality of pressing devices. The heater includes a first portion and a second portion. The second portion of the heater generates a smaller amount of heat than the first portion of the heater. The pressing devices are arranged in a longitudinal direction of the heater and each configured to press at least one of the rotator and the opposed rotator and cause the rotator and the opposed rotator to press each other. The pressing devices include a first pressing device corresponding to the first portion of the heater and a second pressing device corresponding to the second portion of the heater, and the first pressing device generates a smaller pressing force than the second pressing device.

In a fixing device, a pressure unit is pressed toward a roller by an arm, to form a nip region. The pressure unit includes a belt configured to contact the roller in a nip region, a pressure pad configured to press the belt in combination with the roller, and a side guide including an end guide surface configured to guide a side end of the belt, and a stay configured to support the pressure pad. A supporting member is located on an outer side of the side guide that is opposite to an inner side on which the end guide surface faces. The supporting member is held between the stay and the arm, the supporting member comprising a contact surface which contacts the side guide and on which the side guide is swayably supported.