There is provided a fuser including: a cylindrical member; an endless belt; a pressing member; a pressing roller; and a lateral guide contacting a lateral end of the endless belt. A part of an outer circumferential surface of the pressing roller is located on a downstream of the second nip area in a first direction. A guide surface of the lateral guide has: a first guide surface located on an opposite side to the pressing roller with respect to a virtual plane including the center of a first nip area and the center of rotation of the cylindrical member, and a second guide surface located on a side of the pressing roller with respect to the virtual plane, located on the downstream side of the rotation axis of the pressing roller in the first direction, and arranged on a same plane as the first guide surface.

A fixing device includes a belt member. The belt member includes a first insulating layer, an electrically-conductive layer, and a second insulating layer in order. The following conditional expression (1) is satisfied,
9.11log RV113.34(1) where RV1 represents a volume resistance of the electrically-conductive layer on a condition that an applied voltage is 100 volts.

According to one embodiment, a fixing device includes an endless rotating body; a plurality of heat-generating members that heats a medium, each heat-generating member being inclined from the transporting direction to a direction of a predetermined angle, and divided by a predetermined length, the plurality of heat-generating members being disposed on an inner side of the endless rotating body; a plurality of driving circuits, each of the plurality of driving circuits being connected to a corresponding heat-generating member of the plurality of heat-generating members, each of the plurality of driving circuits configured to control individual conduction thereof, each of the plurality of heat-generating members configured to selectively generate a discrete amount of heat corresponding to a position through which the medium passes; and a pressing roller that forms a nip with the plurality of heat-generating members, and configured to nip the medium therebetween and carry the medium in the transporting direction.

According to one embodiment, a fixing device includes determination means for determining the size of a medium, heating means for including plural heat-generating members which are two-dimensionally arranged such that the heat-generating members are lined up along two parallel lines or more which are vertical to a transport direction of the medium and divided at locations on the parallel lines, and are disposed so as to come into contact with an inner side of the rotating body, and a switching unit which switches individual conduction, and heats the medium, pressing means for forming a nip by performing pressing and contact at a position of the plural heat-generating members, and heating control means for selecting a group of the heat-generating members which are lined up in the two-dimensional arrangement, conducting the selected group of the heat-generating members, and controlling the heating means.

A fuser device carrying a medium includes a first rotation member that has flexibility, a second rotation member that is installed rotatable so as to carry the medium from an upstream side to a downstream side in the medium carrying direction in cooperation with the first rotation member while nipping the medium between the second rotation member and the first rotation member, and a first pressing member that has a first pressing face pressing the first rotation member toward the second rotation member while being positioned opposing the second rotation member through the first rotation member. The first pressing face has, at the most upstream side of the medium carrying direction, a pressure reducing part that reduces a pressing force of the first rotation member that is applied to the second rotation member.

According to one embodiment, a fixing device includes determination means for determining the size of an image forming area of a medium, heating means for including an endless rotating body, plural heat-generating members which are formed in a perpendicular direction to a transporting direction, inclined by a predetermined angle, and divided by a predetermined length, and are disposed so as to come into contact with an inner side of the rotating body, and a switching unit which switches individual conduction, and heats the medium, pressing means for forming a nip by performing pressing and contact at a position of the plural heat-generating members, and nipping and carrying the medium in the transporting direction along with the heating means, and heating control means for controlling the switching unit to select and conduct heat-generating members and controlling the heating means to heat the medium.

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.

An image heating apparatus includes an endless belt and a rotatable member configured to form a nip for heating a toner image on a recording material therebetween, a substantially stationary pad member and a movable pad member provided along a feeding direction of the recording material and configured to press the endless belt toward the rotatable member from an inside of the endless belt, a moving mechanism configured to move the movable pad member between a first position at which the movable pad member presses the endless belt toward the rotatable member and a second position at which the movable pad member does not press the endless belt toward the rotatable member, and a sheet-like member configured to cover such a surface of the stationary pad member as is opposite to the rotatable member and such a surface of the movable pad member as is opposite to the rotatable member.

A fixing device includes a first unit including a first belt movable in a first direction; a first pressing member pressing the first belt; a first pressing member support supporting the first pressing member variably in attitude relative to the first pressing member support; a first rotating member in contact with the first belt and rotatable in a first rotation direction; and a first rotating member support that supports the first rotating member variably in position relative to the moving member; a second unit facing the first unit in a second direction and including a moving member movable in the first direction to come into contact with the first belt; and a third unit facing the second unit with the first unit in between in the second direction and supported by the second and third units movably in the second direction between the second unit and the third unit.

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.