A sheet processing apparatus for processing sheets includes: a stack tray on which a sheet is stacked; a discharge roller pair composed of first and second rollers and configured to discharge a sheet onto the stack tray, the second roller being configured to be movable between a pressure contact position to contact with the first roller and a retracting position to separate from the first roller; and a pressure contact/separation mechanism for moving the second roller from the retracting position to the pressure contact position. The pressure contact/separation mechanism changes the timing at which the second roller reaches the pressure contact position according to the type of a sheet to be discharged.

A sheet processing apparatus for processing sheets includes: a stack tray on which a sheet is stacked; a discharge roller pair composed of first and second rollers and configured to discharge a sheet onto the stack tray, the second roller being configured to be movable between a pressure contact position to contact with the first roller and a retracting position to separate from the first roller; and a pressure contact/separation mechanism for moving the second roller from the retracting position to the pressure contact position. The pressure contact/separation mechanism changes the timing at which the second roller reaches the pressure contact position according to the type of a sheet to be discharged.

In some examples, a sheet processing machine includes at least one infeed system including at least one transport means including at least one upper holder and at least one lower holder. The at least one transport means can be and/or is arranged in at least three states: a maximally closed state corresponding to a minimal distance, a minimally closed state corresponding to a maximal distance, and an at least one mean state corresponding to at least one mean distance between at least one upper holding surface at least of the respective upper holder, and at least one lower holding surface of the lower holder of the at least one transport means that is assigned to the respective upper holder. During a machine cycle, the at least one transport means has each of the minimally closed state, the maximally closed state, and the at least one mean state at least once.

In some examples, a sheet processing machine includes at least one infeed system including at least one transport means including at least one upper holder and at least one lower holder. The at least one transport means can be and/or is arranged in at least three states: a maximally closed state corresponding to a minimal distance, a minimally closed state corresponding to a maximal distance, and an at least one mean state corresponding to at least one mean distance between at least one upper holding surface at least of the respective upper holder, and at least one lower holding surface of the lower holder of the at least one transport means that is assigned to the respective upper holder. During a machine cycle, the at least one transport means has each of the minimally closed state, the maximally closed state, and the at least one mean state at least once.

A medium aligning apparatus includes a load tray including a load surface on which a medium discharged from a discharge member that discharges a medium is loaded, a first aligning surface that aligns a plurality of mediums loaded on the load tray by positioning rear ends of the mediums, and a second aligning surface that aligns the mediums by positioning the rear ends of the mediums loaded on the load tray. In the medium aligning apparatus, the first aligning surface and the second aligning surface are switchable, and an angle formed between a wall surface in the discharge tray that receives the mediums discharged from the load tray, the wall surface having the rear ends of the mediums come in contact therewith, and the second aligning surface is smaller than an angle formed between the wall surface and the first aligning surface.

A medium aligning apparatus includes a load tray including a load surface on which a medium discharged from a discharge member that discharges a medium is loaded, a first aligning surface that aligns a plurality of mediums loaded on the load tray by positioning rear ends of the mediums, and a second aligning surface that aligns the mediums by positioning the rear ends of the mediums loaded on the load tray. In the medium aligning apparatus, the first aligning surface and the second aligning surface are switchable, and an angle formed between a wall surface in the discharge tray that receives the mediums discharged from the load tray, the wall surface having the rear ends of the mediums come in contact therewith, and the second aligning surface is smaller than an angle formed between the wall surface and the first aligning surface.

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 stacker includes a sheet stacking portion, a guide portion, and an air blower. The sheet stacking portion is configured to stack a sheet bundle. The guide portion is configured to receive a leading end of a sheet conveyed toward the sheet stacking portion and guide the sheet downstream in a sheet conveyance direction in which the sheet is conveyed. The air blower is disposed above the sheet stacking portion and configured to blow air toward the sheet on a downstream side, in the sheet conveyance direction, from a position at which the guide portion receives the leading end of the sheet.

A sheet stacker includes a sheet stacking portion, a guide portion, and an air blower. The sheet stacking portion is configured to stack a sheet bundle. The guide portion is configured to receive a leading end of a sheet conveyed toward the sheet stacking portion and guide the sheet downstream in a sheet conveyance direction in which the sheet is conveyed. The air blower is disposed above the sheet stacking portion and configured to blow air toward the sheet on a downstream side, in the sheet conveyance direction, from a position at which the guide portion receives the leading end of the sheet.