A post-processing apparatus includes a conveyance unit, a discharge port, a tray, an elevation unit, a detection unit, and a control unit. The conveyance unit conveys a print medium supplied from an image forming apparatus. The discharge port discharges the print medium conveyed by the conveyance unit. The tray is stacked with the print medium discharged from the discharge port and can be raised and lowered in a vertical direction. The elevation unit raises and lower the tray in the vertical direction. The detection unit detects a top surface of an uppermost print medium of one or more sheets of print media stacked on the tray. The control unit controls the conveyance unit and the elevation unit and hold a relative position of the top surface with respect to the discharge port if the print medium is discharged from the discharge port at a first position. The control unit causes the conveyance unit to convey the print medium at a first speed if a discharge time from a first timing indicating the timing relating to discharge of the print medium from the discharge port to a second timing indicating the timing when the print medium is detected by the detection unit is a first time and causes the conveyance unit to convey the print medium at a second speed different from the first speed if the discharge time is a second time.

A sheet processing apparatus comprising: a conveying unit configured to have a roller that conveys a sheet in a conveyance direction; a first detecting device disposed downstream of the conveying unit in the conveyance direction; a second detecting device disposed downstream of the first detecting device in the conveyance direction; a boring unit configured to have a punch that performs boring in the sheet; and a control unit is used. The first detecting device and the second detecting device each detect passage of a leading edge of the sheet being conveyed. The control unit calculates an actual conveyance speed of the sheet on the basis of detection results of the first detecting device and the second detecting device, and controls rotation of the roller, on the basis of the actual conveyance speed, so that the sheet is conveyed at a predetermined target speed.

A sheet conveyer, having a sheet tray, a tray-driving mechanism, a conveyance guide, a feed roller, a conveyer-driving mechanism, a first sensor, and a controller, is provided. The controller controls the tray-driving mechanism and the conveyer-driving mechanism, during a sequential conveying action, when the first sensor detects an upper-surface level being at a lower limit of a correct range, delay a lift-start timing, at which the tray-driving mechanism starts moving the sheet tray upward, to be later at least than a timing, at which the feed roller after feeding one of the sheets completely and pausing resumes rotating for feeding a next one of the sheets, and cause the sheet tray to complete moving to a higher position prior to completion of feeding of the next sheet.

A sheet feeding device includes a drive unit that rotates a roll of a wound sheet in a first direction and in a second direction, a sensor having an output which changes according to a distance between a detecting position facing a peripheral surface of the roll and the peripheral surface of the roll, and a control unit that determines an amplification factor of the sensor on the basis of data. The data is acquired by changing the amplification factor while the roll is rotated once in the second direction and includes a plurality of the output value acquired at different rotation angles.

A medium feeding device includes a storage unit that stores media in a form of a sheet, a delivery unit that is disposed downstream in a medium delivery direction relative to the media stored in the storage unit and that delivers the media individually, a transfer unit that is disposed above the storage unit and that sticks by suction to each of the media stored in the storage unit and transfers the media to the delivery unit individually, and a fluffing unit that is disposed beside the media stored in the storage unit in a direction intersecting the medium delivery direction. The fluffing unit fluffs an upper-side region of the media in a state of being separated by blowing air toward a side of the media. The medium feeding device further includes plural position detection units that are arranged in a region that is on the delivery unit side relative to a position of a downstream end portion, in the medium delivery direction, of each of the media stored in the storage unit and that does not reach a contact portion where the delivery unit comes into contact with the media. The position detection units are arranged at an interval in a width direction of the media intersecting the medium delivery direction. The position detection units detect a position of the downstream end portion, in the medium delivery direction, of each of the media.

A medium feeding device includes a storage unit that stores media in a form of a sheet, a delivery unit that is disposed downstream in a medium delivery direction relative to the media stored in the storage unit and that delivers the media individually, a transfer unit that is disposed above the storage unit and that sticks by suction to each of the media stored in the storage unit and transfers the media to the delivery unit individually, and a fluffing unit that is disposed beside the media stored in the storage unit in a direction intersecting the medium delivery direction. The fluffing unit fluffs an upper-side region of the media in a state of being separated by blowing air toward a side of the media. The medium feeding device further includes plural position detection units that are arranged in a region that is on the delivery unit side relative to a position of a downstream end portion, in the medium delivery direction, of each of the media stored in the storage unit and that does not reach a contact portion where the delivery unit comes into contact with the media. The position detection units are arranged at an interval in a width direction of the media intersecting the medium delivery direction. The position detection units detect a position of the downstream end portion, in the medium delivery direction, of each of the media.

A sheet processing system according to an embodiment includes a tray that supports a sheet on opposite sides of the sheet orthogonal to a conveyance direction of the sheet. The tray includes a first adjustable support and second adjustable support positioned opposite the first adjustable support in the direction orthogonal to the conveyance direction of the sheet. A skew sensor detects a skew angle of the sheet conveyed to the tray. A corner sensor detects positions of each corner on a front end in the downstream direction of the sheet conveyed to the tray. A controller controls movement of the first and second adjustable supports based on the detected skew angle and the detected positions of each corner on the front end of the sheet conveyed to the tray so that the sheet is conveyed to the tray without jamming.

A sheet processing system according to an embodiment includes a tray that supports a sheet on opposite sides of the sheet orthogonal to a conveyance direction of the sheet. The tray includes a first adjustable support and second adjustable support positioned opposite the first adjustable support in the direction orthogonal to the conveyance direction of the sheet. A skew sensor detects a skew angle of the sheet conveyed to the tray. A corner sensor detects positions of each corner on a front end in the downstream direction of the sheet conveyed to the tray. A controller controls movement of the first and second adjustable supports based on the detected skew angle and the detected positions of each corner on the front end of the sheet conveyed to the tray so that the sheet is conveyed to the tray without jamming.

Examples described herein include a print media edge repair system that includes a first repair element disposed adjacent to a media handling path to repair a leading edge of a sheet of print media as the sheet of print media moves into a position relative to a printing system associated with the print media edge repair system. The print media repair system may also include a second repair element disposed opposite the first repair element across the media handling path to repair a trailing edge of the sheet of print media as the sheet of print media moves into the position relative to a printing system.

A sheet folding device, which is included in an image forming system and uses a sheet folding method, includes first and second drive motors, a first sheet conveyor driven by the first drive motor and configured to receive and convey a sheet toward a downstream side of a sheet conveying direction, a second sheet conveyor driven by the second drive motor and configured to receive the sheet conveyed from the first sheet conveyor and to convey the sheet to the downstream side of the sheet conveying direction, and a controller configured to fold the sheet to a predetermined folding length set according to an amount of conveyance of the sheet by the second sheet conveyor while the sheet is being held between the first and second sheet conveyors, and to perform a feedback control with an integral gain to the second drive motor.