In accordance with an embodiment, a sheet processing apparatus comprises a standby section configured to buffer a sheet; a processing section configured to receive sheets supplied from the standby section and execute a post processing on the sheets; a rotational shaft configured to rotate around an axis of rotation; a paddle arranged in the rotational shaft and configured to contact the sheet and move the sheets by rotating with the rotational shaft, the paddle being configured to slide the sheets on the processing section to a stopper for aligning the sheets; and a controller configured to control a rotational speed of the rotational shaft to rotate the paddle at a first speed, and control the rotational speed of the rotational shaft to rotate the paddle at a second speed slower than the first speed while the paddle contacts the sheets on the processing section for aligning.

A sheet processing apparatus, including: a conveyance path in which a sheet is conveyed in a predetermined conveyance direction; a rotary member pair configured to nip the sheet conveyed in the conveyance path and rotate to perform folding processing on the sheet; and a guide portion provided between one rotary member of the rotary member pair and the conveyance path and configured to guide a downstream edge of a sheet conveyed in the predetermined conveyance direction, wherein, in case that a sheet is conveyed in the conveyance path in the predetermined conveyance direction, the guide portion guides a downstream edge of the sheet in the predetermined conveyance direction in a state in which the guide portion is held in contact with the one rotary member.

A sheet processing apparatus, including: a rotary member pair configured to nip a sheet conveyed in a conveyance path and rotate to fold the sheet; and a guide portion provided between one rotary member of the rotary member pair and the conveyance path, the one rotary member including: a first part; and a second part, wherein a first distance between the first part and a rotary shaft center of the one rotary member is greater than a second distance between the second part and the rotary shaft center, and wherein the guide portion is positioned at a first position in case that the second part is positioned at a first rotational position, and the guide portion is positioned at a second position different from the first position in a distance from the rotary shaft center in case that the second part is positioned at a second rotational position.

In an image forming apparatus, includes a sheet supplying portion, an intermediate tray, a discharge tray, a post-processing portion, a jam detecting portion, a discontinuation control portion, a dummy feed control portion, and a supplementary printing control portion. The dummy feed control portion, after the paper jam is solved, causes an image forming portion to execute a dummy feed process in which sheets as many as a predetermined dummy feed number are conveyed from the sheet supplying portion to the intermediate tray, without formation of images on the sheets. The supplementary printing control portion cause the image forming portion to execute a supplementary printing process in which images are formed on one or more sheets, the images being images of remaining pages that are obtained by excluding pages corresponding to the dummy feed number of sheets starting from a beginning page, from all pages.

A holding unit of a rotation unit includes a shaft hole through which a rotation shaft passes, and is fixed in a state of being attached to the rotation shaft by sliding in an axis direction of the rotation shaft. A conveying force applying unit includes a base portion provided with a fitting hole that fits an outer circumference of the holding unit and an opening portion in communication with the fitting hole, and a contact part provided to the base portion. The base portion is configured to deform, and the conveying force applying unit is configured to be attached to and detached from the holding unit via the opening portion in a direction crossing the axis direction of the rotation shaft.

A sheet conveyance apparatus includes first and second conveyance paths, a conveyance roller pair, first and second conveyance guides, and a holding unit. The reverse unit reverses a sheet having passed through the first conveyance path. The second conveyance path conveys the sheet having passed through the first conveyance path between the reverse unit and the first conveyance path. The conveyance roller pair nips and convey the reversed sheet. The first conveyance guide forms the second conveyance path and the second conveyance guide forms the second conveyance path. The holding unit moveably holds the first conveyance guide. The first conveyance guide moves between a first position located at a first distance from the second conveyance guide and a second position located at a second distance. The sheet reversed by the reverse unit is conveyed toward the conveyance roller pair by the first conveyance guide located at the first position.