A fixing device (50) includes a fixing belt (70), a pressure member (80), and a heating section (90). The heating section (90) faces an inner peripheral surface of the fixing belt (70). The heating section (90) includes a heater (HT), a first heat sensitive body (SM11), and a second heat sensitive body (SM21). The second heat sensitive body (SM21) differs from the first heat sensitive body (SM11). The heater (HT) has a first heater portion (AE1). The first heater portion (AE1) is one end portion of a pair of end portions of the heater (HT) in a longitudinal direction thereof. The first heat sensitive body (SM11) and the second heat sensitive body (SM21) face the first heater portion (AE1) and are aligned in a conveyance direction (DC) of a sheet (S).

An image forming system includes an image forming apparatus, a varnish application apparatus, and a controller. When the image forming apparatus is in a standby state and preheating of varnish in a tank by a heater is completed, if an image forming job of forming a toner image on a first recording material and applying varnish thereto by a varnish coater is received, the controller controls a guide member to guide the first recording material to a first conveyance path. When the image forming apparatus is in a standby state and preheating of varnish in the tank by the heater is not completed, if an image forming job of forming a toner image on a second recording material and not applying varnish thereto by the varnish coater is received, the controller controls the guide member to guide the second recording material to a second conveyance path.

A transport device includes: a first transport body; a second transport body that is movable between a contact position and a separate position with respect to the first transport body and that nips a transported material with the first transport body at the contact position; and a transport section that includes a holder to hold a leading end portion of the transported material and that transports the transported material toward a nip region where the first transport body and the second transport body nip the transported material in a state in which the second transport body is located at the separate position. After holding of the leading end portion by the holder for the transported material transported by the transport section has been released, the second transport body nips the transported material with the first transport body and transports the transported material.

A fixation device includes: a heating roll that heats a transported recording medium whose front end is gripped by a gripping part while rotating; a pressing roll that is disposed so as to face the heating roll, around which at least a part of the transported recording medium is wound, and presses the wound part of the recording medium toward the heating roll while rotating; a peeling part that peels the recording medium off from the pressing roll by lifting the front end of the recording medium up in a state where the front end of the recording medium has passed a portion where the pressing roll and the heating roll face each other and is no longer gripped by the gripping part; and a reducing part that reduces momentum of the peeling part lifting the front end of the recording medium up.

In general, a fixing device according to an embodiment includes an endless belt, a pressure element, a heating member, an adjustment mechanism, and a controller. The pressure element conveys a sheet while interposing the sheet under pressure between the same and the endless belt. The heating member is provided on the inner side of the endless belt and has a heat generating element for heating the endless belt. The adjustment mechanism moves at least one of the heating member and the pressure element in such a direction as to bring the one closer to or away from the other, to adjust the nip width which is the length of an interposing and pressurizing region in a sheet conveyance direction, the interposing and pressurizing region being formed by the heating member and the pressure element to interpose the endless belt under pressure. The controller controls the adjustment mechanism so that A>B≧N is satisfied, where A is the nip width during a fixing process in which the sheet is heated to fix a color material onto the sheet, B is the nip width during temperature raising of the heating member to be conducted before the fixing process, and N is the length of the heat generating element in the sheet conveyance direction.

A fixing device includes: a fixing belt with no ends configured to stretch rotatably; a heating unit configured to heat the fixing belt; a fixing member disposed outside the fixing belt and configured to be in contact with the fixing belt by pressurizing; a pressing member disposed inside the fixing belt and configured to press the fixing member with the fixing belt involved; and a lubricant supply unit configured to supply a lubricant to the inner periphery of the fixing belt so as to supply the lubricant between the pressing member and the fixing belt, wherein the lubricant supply unit is disposed inside the fixing belt, configured to hold the lubricant, and includes a holding unit provided with a lubricant ejection port having a longitudinal shape and extending along a width direction of the fixing belt.

A fixing device includes a separator disposed downstream from a nip former in a recording medium conveyance direction and isolated from a pressure rotator via a fixing belt. The separator stretches the fixing belt. A presser is interposed between a fixing nip formed between the living belt and the pressure rotator and an upstream end of the separator in a 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 pressure adjuster, contacting the pressure rotator, changes a pressing position of the pressure rotator relative to the fixing belt to adjust pressure exerted from the pressure rotator to the fixing belt. A presser position adjuster, contacting the presser, changes a presser position of the presser relative to the fixing belt according to the pressing position of the pressure rotator.

An image forming apparatus including a normal power mode and a power saving mode includes a fixing unit configured to bring first and second rotary members into contact with each other to form a nip portion and fix a toner image onto a sheet with a pressing force of the nip portion. The image forming apparatus executes a rotation operation or a separation operation to separate the first and second rotary members from each other in order to prevent a deformation of the nip portion in the fixing unit. The image forming apparatus measures a time during which the first and second rotary members are in contact with each other without rotating. The image forming apparatus determines whether to execute the separation operation or the rotation operation based on a result of the power mode determination and the measured time.

A transport device includes: a first rotational member; a second rotational member that forms a nip with the first rotational member; a guide member that guides the medium in a predetermined direction; a changing part that supports the second rotational member so as to be rotatable and that moves the second rotational member to change a nip state between the second rotational member and the first rotational member; and an interposed member supported by the changing part and nipped between the first rotational member and the guide member, the interposed member including, in an intersecting direction intersecting a direction in which the interposed member is nipped, multiple portions having different thicknesses, the interposed member being nipped at any one of the multiple portions, while being moved in the intersecting direction in accordance with the movement of the second rotational member.

A nip forming device includes an endless belt that is flexible and rotates and a nip former that is disposed opposite an inner circumferential face of the endless belt. A pressure rotator presses against the nip former via the endless belt to form a nip between the endless belt and the pressure rotator, through which a conveyed object is conveyed. A separator is disposed downstream from the nip in a conveyance direction of the conveyed object. The separator separates the conveyed object from the endless belt. The separator includes a non-contact portion separated from the endless belt and a contact portion that contacts the endless belt. The contact portion retains a gap having a predetermined size between the non-contact portion and the endless belt.