An image forming apparatus includes an image forming unit, a fixing unit including a tubular film and an opposed member to form a first nip, a conveying unit including a second nip, the pressure variable mechanism changing a pressure of the second nip, a control unit controlling the pressure variable mechanism, and an acquisition unit acquiring information about a length of the recording material. The control unit controls the pressure variable mechanism according to the information so that the recording material is conveyed by the second nip set to a first pressure when the length of the recording material is less than a predetermined length, and the recording material is conveyed by the second nip set to a second pressure lower than the first pressure when the length of the recording material is equal to or greater than the predetermined length.

There is provided a post processing device including a mounting portion on which a medium is temporarily mounted, a post processing unit that performs post processing on the medium mounted on the mounting portion, a discharging tray on which the medium is stacked after being discharged, and a suppressing unit that suppresses deformation of the medium mounted on the mounting portion.

A paper correction apparatus B corrects a curl of a sheet S by passing the sheet S through curved paper conveying routes CCP1 and CCP2 whose curving amounts can be changed. The paper correction apparatus B is provided with a control unit B3 which sets the curving amounts of the curved paper conveying routes CCP1 and CCP2, and changes a sheet interval in accordance with the curving amounts which are set. By this configuration, it is possible to inhibit the productivity from being reduced due to paper correction during performing post-printing processes in a finisher which is located in the downstream side of the paper correction apparatus B.

A post-processing device is provided with a post-processing unit which performs post-processing of a recording medium on which recording is performed, a transport path through which the recording medium is transported, or a deformation suppressing unit which suppresses deformation of the recording medium on a mounting unit on which the recording medium is mounted, in which the deformation suppressing unit is controlled based on a predetermined parameter related to recording processing with respect to the recording medium.

An image forming apparatus includes: a conveyance section configured to convey a sheet in a direction opposite to a first conveyance direction during image formation, the direction being a second conveyance direction; and a distortion correction section disposed on an upstream side of a transfer nip in the first conveyance direction and configured to correct, when the sheet is conveyed by the conveyance section in the second conveyance direction, distortion of the sheet generated when the sheet passes through a fixing nip.

The curl correction device includes a first guide that guides a sheet to a nip portion between a first rotation member and a second rotation member, a support portion that rotatably supports the first guide about a fulcrum on the downstream side of the first guide, and a restriction portion that restricts a rotation of the first guide rotating about the fulcrum by being in contact with the first guide. The first guide is rotatable about the fulcrum so as to become separated from the restriction portion.

A paper feeding device in an embodiment includes a roll-paper storing unit, a curl rectifying unit, and a cutting unit. The roll-paper storing unit is capable of storing roll paper. The curl rectifying unit is disposed on a downstream side of the roll-paper storing unit in a conveying direction of a sheet let out from the roll paper and rectifies a curl of the sheet. The cutting unit is disposed on the downstream side of the curl rectifying unit in the conveying direction and cuts the sheet.

An image forming apparatus includes an image forming section, a sheet supply section, and first and second curl correction mechanisms disposed in a sheet conveyance path between the sheet supply section and the image forming section and configured to curve a recording medium conveyed thereto. The first and second curl correction mechanisms are configured to apply curves to the recording medium in different curvature directions.

A curl correcting apparatus includes rollers, a motor, and a clutch portion. The rollers are curl correction-use rollers which are arranged in parallel to each other in a pressure-contact state and which are different in hardness. The motor is a motor capable of rotating in forward and reverse directions relative to a correction-amount adjusting portion that changes and adjusts a distance to the rollers as a result of an eccentric cam that integrally rotates in accordance with a rotation amount of a rotation shaft, pressing against the rollers. The clutch portion transmits a rotary driving force of the motor to the rollers during the forward rotation and to a rotation shaft during the reverse rotation.

An image forming apparatus includes an image forming device that forms an image and a controller that acquires an image reading result of reading of an image of a transfer medium and determines a curling state of the transfer medium. In the determination of the curling state, a prescribed parameter extracted from the image reading result is compared with a prescribed parameter reference, thereby deciding the curling state according to the comparison result.