Sheet post-processing unit and image forming apparatus

A sheet post-processing unit, comprising:

• first sheet stacking means for stacking sheets sequentially discharged one after another;
• sheet conveying means including at least one roller rotatably supported by an arm movably and vertically rockingly supported along an axis, and an actuator for moving said arm in a vertical direction and capable of selectively conveying each sheet to be discharged to said first sheet stacking means in downstream and upstream directions of a sheet conveying direction and of separating from the sheet by moving in the vertical direction;
• an upstream side regulating member for aligning each sheet stacked on said sheet stacking means by hitting against an upstream edge of the sheet;
• intersectional moving means for moving said arm of said sheet conveying means in a direction intersecting with the sheet conveying direction along the axis;
• an intersectional regulating member for aligning each sheet by hitting against an edge of the sheet on a side intersecting with the sheet conveying direction;
• a control section for setting a moving distance of said intersectional moving means corresponding to a size each sheet to be discharged on the basis of information relating to sizes of sheets sequentially discharged to said sheet stacking means;
• post-processing means for post-processing sheets aligned by said upstream side regulating member and said intersectional regulating means;
• second sheet stacking means, disposed in the vicinity of said first sheet stacking means and movable in a vertical direction, for stacking sheets;
• and
• transfer means for clamping and transferring sheets stacked on said first sheet stacking means to said second sheet stacking means,
• wherein said at least one roller of said sheet conveying means abuts an uppermost sheet among sheets stacked on said first sheet stacking means and said intersectional moving means moves said at least one roller in the intersecting direction by the moving distance corresponding to a sheet size set by said control section to hit against and align the uppermost sheet with said upstream side regulating member and said intersectional regulating member,
• wherein said post-processing means includes a stapling device for binding the aligned bundle of sheets,
• wherein said second sheet stacking means includes a tray, and
• wherein said transfer means includes a sheet bundle discharging member for discharging the bound bundle of sheets to said tray.

An image forming apparatus, comprising:

• image forming means for forming images;
• sheet stacking means for stacking sheets sequentially discharged one after another;
• sheet conveying means including at least one roller rotatably supported by an arm movably and vertically rockingly supported along an axis, and an actuator for moving said arm in a vertical direction and capable of selectively conveying each sheet to be discharged in downstream and upstream directions of a sheet conveying direction and of separating from the sheet by moving in the vertical direction;
• an upstream side regulating member for aligning each sheet stacked on said sheet stacking means by hitting against an upstream edge of the sheets;
• intersectional moving means for moving said arm of said sheet conveying means in a direction intersecting with the sheet conveying direction along the axis;
• an intersectional regulating member for aligning each sheet by hitting against an edge of the sheet on a side intersecting with the sheet conveying direction;
• a control section for setting a moving distance of said intersectional moving means corresponding to a size of each sheet to be discharged on the basis of information relating to sizes of sheets sequentially discharged to said sheet stacking means;
• and
• clamping means for clamping sheets to prevent the sheets from following a moving succeeding sheet when the succeeding sheet is stacked on the preceding sheet stacked on said sheet stacking means,
• wherein said at least one roller of said sheet conveying means abuts an uppermost sheet among sheets stacked on said sheet stacking means and said intersectional moving means moves said at least one roller in the intersecting direction by the moving distance corresponding to the sheet size set by said control section to hit against and align the uppermost sheet with said upstream side regulating member and said intersectional regulating member.