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 detecting apparatus including: a detection unit including a lever member having an abutment surface abutting a conveying sheet and a holding member configured to hold the lever member, the detection unit moved by the lever member pushed by the sheet; a first urging portion configured to urge the holding member to a waiting position after the sheet is separated from the abutment surface; a support portion configured to support the lever member movable with respect to the holding member to move the lever member to a retracted position for allowing the sheet to pass the lever member contacting a surface of the sheet when the holding member is in the waiting position; and a second urging portion configured to urge the lever member so that the lever member is moved from the retracted position to a position in which the abutment surface abuts a succeeding sheet.

A sheet detecting apparatus including: a detection unit including a lever member having an abutment surface abutting a conveying sheet and a holding member configured to hold the lever member, the detection unit moved by the lever member pushed by the sheet; a first urging portion configured to urge the holding member to a waiting position after the sheet is separated from the abutment surface; a support portion configured to support the lever member movable with respect to the holding member to move the lever member to a retracted position for allowing the sheet to pass the lever member contacting a surface of the sheet when the holding member is in the waiting position; and a second urging portion configured to urge the lever member so that the lever member is moved from the retracted position to a position in which the abutment surface abuts a succeeding sheet.

An orientation correcting device includes a first transporting unit that nips and transports a sheet; a detecting unit that detects a tilt of the sheet that is transported by the first transporting unit; a second transporting unit that nips and transports the sheet that has been transported by the first transporting unit; a flexure forming unit that, with the second transporting unit stopped, forms a flexure in the sheet as a result of causing the sheet that is transported by the first transporting unit to strike against the second transporting unit; and a moving unit that, with the second transporting unit stopped and the flexure formed in the sheet by the flexure forming unit, moves the second transporting unit in a crossing direction that crosses a transport direction of the sheet in accordance with an amount and a direction of the sheet tilt detected by the detecting unit.

An orientation correcting device includes a first transporting unit that nips and transports a sheet; a detecting unit that detects a tilt of the sheet that is transported by the first transporting unit; a second transporting unit that nips and transports the sheet that has been transported by the first transporting unit; a flexure forming unit that, with the second transporting unit stopped, forms a flexure in the sheet as a result of causing the sheet that is transported by the first transporting unit to strike against the second transporting unit; and a moving unit that, with the second transporting unit stopped and the flexure formed in the sheet by the flexure forming unit, moves the second transporting unit in a crossing direction that crosses a transport direction of the sheet in accordance with an amount and a direction of the sheet tilt detected by the detecting unit.

A sheet conveying device, which is included in an image forming apparatus, includes a plurality of position detectors, a leading end detector, and a position adjuster. The plurality of position detectors is configured to detect a position of a sheet. The leading end detector is configured to detect a leading end of the sheet. The position adjuster is configured to, based on a detection result obtained by the plurality of position detectors, rotate in a rotation direction of the sheet within a plane of conveyance of the sheet to change the position of the sheet the position adjuster grips the sheet under conveyance to cause the leading end detector to rotate with the position adjuster in the rotation direction of the sheet within the plane of conveyance of the sheet.

A sheet conveying device, which is included in an image forming apparatus, includes a plurality of position detectors, a leading end detector, and a position adjuster. The plurality of position detectors is configured to detect a position of a sheet. The leading end detector is configured to detect a leading end of the sheet. The position adjuster is configured to, based on a detection result obtained by the plurality of position detectors, rotate in a rotation direction of the sheet within a plane of conveyance of the sheet to change the position of the sheet the position adjuster grips the sheet under conveyance to cause the leading end detector to rotate with the position adjuster in the rotation direction of the sheet within the plane of conveyance of the sheet.

In some examples, a sheet processing machine includes at least one sensor device that includes at least two sensors configured as a camera. The sheet processing machine further includes at least one infeed system. The at least one sensor device is configured to control, by open-loop control and/or closed-loop control, at least one servo drive of the infeed system as a function of at least one sheet of sheets being detected by the at least two sensors. The at least two sensors are configured to selectively detect at least one edge and/or printing mark of the sheets. Some examples likewise relate to a method for controlling, by open-loop control and/or closed-loop control, at least one component of a sheet processing machine.

In some examples, a sheet processing machine includes at least one sensor device that includes at least two sensors configured as a camera. The sheet processing machine further includes at least one infeed system. The at least one sensor device is configured to control, by open-loop control and/or closed-loop control, at least one servo drive of the infeed system as a function of at least one sheet of sheets being detected by the at least two sensors. The at least two sensors are configured to selectively detect at least one edge and/or printing mark of the sheets. Some examples likewise relate to a method for controlling, by open-loop control and/or closed-loop control, at least one component of a sheet processing machine.

A sheet conveying apparatus includes a pair of first conveying rollers, a pair of second conveying rollers provided at a downstream of the pair of first conveying rollers in a conveying direction of a sheet, a loop being formed in the sheet when a head of the sheet conveyed by the pair of first conveying rollers butts against the pair of second conveying rollers, and a controller which executes a first control mode in which the sheet is conveyed by the pair of first conveying rollers and the pair of second conveying rollers without dissolving the loop formed in the sheet, or a second control mode in which the loop formed in the sheet is dissolved, and the sheet nipped by the pair of first conveying rollers and the pair of second conveying rollers is conveyed.