A sheet processing apparatus includes two pressing members and an advancing-receding unit. The pressing members nip and press against a fold section of a sheet. The advancing-receding unit causes the pressing members to repeatedly press against the fold section by causing at least one of the pressing members to advance to and recede from the other pressing member. The advancing-receding unit varies a reception separation amount and a post-receding separation amount from each other and sets the post-receding separation amount to be smaller than the reception separation amount. The reception separation amount is a separation amount by which the pressing members are separated from each other when the fold section is to be received between the pressing members. The post-receding separation amount is a separation amount by which the pressing members that have pressed against the fold section are separated from each other after receding from the fold section.

A sheet processing apparatus includes two pressing members and an advancing-receding unit. The pressing members nip and press against a fold section of a sheet. The advancing-receding unit causes the pressing members to repeatedly press against the fold section by causing at least one of the pressing members to advance to and recede from the other pressing member. The advancing-receding unit varies a reception separation amount and a post-receding separation amount from each other and sets the post-receding separation amount to be smaller than the reception separation amount. The reception separation amount is a separation amount by which the pressing members are separated from each other when the fold section is to be received between the pressing members. The post-receding separation amount is a separation amount by which the pressing members that have pressed against the fold section are separated from each other after receding from the fold section.

A sheet feeding device includes: a sheet stacking unit that stacks a bundle of sheets; a pick-up roller that is enabled to move up and down and sends a sheet of the bundle of sheets toward downstream side in a carrying direction; a pair of rollers that is arranged at downstream side in the carrying direction, and when multiple sheets are sent out by the pick-up roller, that separates the first sheet from the second sheet or later; a separation member that is arranged between the pick-up roller and the pair of rollers and that is in contact with a leading end of the sheet and limits the number of the sheet carried to the pair of rollers; and a hardware processor that determines a height position of the pick-up roller corresponding to a type of the sheet and sets the pick-up roller to be at the determined height position.

A sheet stacking tray that includes a single pneumatic baffle which uses the pressure differential caused by the flow of air across a horizontal planar surface of the pneumatic baffle to hold the lead edge of sheets driven by an input nip into the sheet stacking tray above a stack especially for longer and lighter weight sheets as they are driven by the input nip to a registration wall.

A sheet stacking tray that includes a single pneumatic baffle which uses the pressure differential caused by the flow of air across a horizontal planar surface of the pneumatic baffle to hold the lead edge of sheets driven by an input nip into the sheet stacking tray above a stack especially for longer and lighter weight sheets as they are driven by the input nip to a registration wall.

In a saddle-stitching apparatus, when a sheet is transported to a center-folding unit, a folding blade moves from a retrieved position to a nip position between a pair of folding rollers. A forward end of the folding blade comes into contact with a fold of the sheet, so that the sheet is folded along the fold. When the sheet is attached to the nip position between the folding rollers, the folding rollers start rotating and then, the folding blade inserts the center-folded sheet between the folding rollers. After the center-fold finishing is completed, the rotations of the folding rollers stop in timing at which the folding blade is pulled out of the nip position between the folding rollers. When pulling the folding blade out of the nip position between the folding rollers, the rotations of the folding rollers restart.

In a saddle-stitching apparatus, when a sheet is transported to a center-folding unit, a folding blade moves from a retrieved position to a nip position between a pair of folding rollers. A forward end of the folding blade comes into contact with a fold of the sheet, so that the sheet is folded along the fold. When the sheet is attached to the nip position between the folding rollers, the folding rollers start rotating and then, the folding blade inserts the center-folded sheet between the folding rollers. After the center-fold finishing is completed, the rotations of the folding rollers stop in timing at which the folding blade is pulled out of the nip position between the folding rollers. When pulling the folding blade out of the nip position between the folding rollers, the rotations of the folding rollers restart.

A sheet processing apparatus that can suppress a reduction in a quality of a finish of a fold part of a stack of center-folded sheets without losing an ease of center-folding. The sheet processing apparatus comprises a creasing unit for forming a folding stripe on a sheet so as to facilitate folding the sheet, and an acquisition unit for acquiring information related to a thickness of the sheet. One or more sheets to be provided with folding stripes are determined, from among a plurality of sheets to be folded, according to the information related to the thickness of the sheets, and each of the determined one or more sheets are provided with a folding stripe.

A sheet processing apparatus that can suppress a reduction in a quality of a finish of a fold part of a stack of center-folded sheets without losing an ease of center-folding. The sheet processing apparatus comprises a creasing unit for forming a folding stripe on a sheet so as to facilitate folding the sheet, and an acquisition unit for acquiring information related to a thickness of the sheet. One or more sheets to be provided with folding stripes are determined, from among a plurality of sheets to be folded, according to the information related to the thickness of the sheets, and each of the determined one or more sheets are provided with a folding stripe.

According to an embodiment, a sheet post-processing apparatus according to the embodiment includes a paddle member and a controller. The paddle member rotates around a rotating shaft, presses a plurality of sheets held on a processing tray against a stopper and aligns ends of the sheets in a sheet transport direction. After the ends of the sheets in the sheet transport direction are aligned, the controller further rotates the paddle member, and stops rotation of the paddle member in a state that the paddle member comes in contact with the sheets held on the processing tray.