Sheet processing apparatus and method therefor

A sheet processing apparatus comprising:

• a staple tray having a sheet stacking face on which a sheet discharged from an image forming apparatus may be stacked;
• a rear end fence positioned to receive and vertically align a tail end of a sheet stacked on said staple tray;
• a pair of jogger fences that laterally align a sheet on said staple tray by contacting a side of the sheet perpendicular to a conveying direction of the sheet;
• a stapling device positioned to staple the vertically aligned tail ends of a bundle of at least two of the sheets stacked on said staple tray;
• a pressure member that is movable in a direction of a thickness of the bundle of sheets stacked on said staple tray;
• and
• a controller controlling said pressure member to press an upper face of the sheet adjacent to said rear end fence every time that a predetermined number of the sheets is discharged onto said staple tray.

A sheet processing apparatus comprising:

• a staple tray having a sheet stacking face on which a sheet discharged from an image forming apparatus may be stacked;
• a rear end fence positioned to receive and vertically align a tail end of a sheet stacked on said staple tray;
• a pair of jogger fences that laterally align a sheet on said staple tray by contacting a side of the sheet perpendicular to a conveying direction of the sheet;
• a stapling device positioned to staple the vertically aligned tail ends of a bundle of at least two of the sheets stacked on said staple tray;
• a limiting pressure member that is movable in a direction of a thickness of the bundle of sheets stacked on said staple tray;
• and
• a controller controlling said limiting pressure member to press an upper face of the sheet adjacent to said rear end fence every time that a predetermined number of the sheets is discharged onto said staple tray.

A sheet processing apparatus comprising:

• a staple tray having a sheet stacking face on which a sheet discharged from an image forming apparatus may be stacked;
• a rear end fence positioned to receive and vertically align a tail end of a sheet stacked on said staple tray;
• a stapling device positioned to staple the vertically aligned tail ends of a bundle of at least two of the sheets stacked on said staple tray;
• a limiting member that is movable in a direction of a thickness of the bundle of sheets stacked on said staple tray;
• and
• a controller which controls a position of said limiting member relative to the sheet stacking face of said staple tray such that the limiting member can assume at least two predetermined positions relative to the sheet stacking face;
• wherein said rear end fence includes a hitting face against which a sheet discharged onto the staple tray strikes, and a first facing face that faces the sheet stacking face of said staple tray and is movable in a direction of the thickness of the sheets stacked on said staple tray, and wherein said first facing face includes said limiting member.

A sheet processing apparatus comprising:

• a staple tray having a sheet stacking face on which a sheet discharged from an image forming apparatus may be stacked;
• a rear end fence positioned to receive and vertically align a tail end of a sheet stacked on said staple tray;
• a stapling device positioned to staple the vertically aligned tail ends of a bundle of at least two of the sheets stacked on said staple tray;
• a pressure member that is movable in a direction of a thickness of the bundle of sheets stacked on said staple tray;
• and
• a controller controlling said pressure member to press an upper face of the sheet adjacent to said rear end fence every time that a predetermined number of the sheets is discharged onto said staple tray;
• wherein said rear end fence includes a hitting face against which a sheet discharged onto the staple tray strikes, and a first facing face that faces the sheet stacking face of said staple tray and is movable in a direction of the thickness of the sheets stacked on said staple tray, and wherein said first facing face includes said pressure member.

A sheet processing apparatus comprising:

• a staple tray having a sheet stacking face on which a sheet discharged from an image forming apparatus may be stacked;
• a rear end fence positioned to receive and vertically align a tail end of a sheet stacked on said staple tray;
• a stapling device positioned to staple the vertically aligned tail ends of a bundle of at least two of the sheets stacked on said staple tray;
• a limiting pressure member that is movable in a direction of a thickness of the bundle of sheets stacked on said staple tray;
• and
• a controller controlling said limiting pressure member to press an upper face of the sheet adjacent to said rear end fence every time that a predetermined number of the sheets is discharged onto said staple tray;
• wherein said rear end fence includes a hitting face against which a sheet discharged onto the staple tray strikes, and a first facing face that faces the sheet stacking face of said staple tray and is movable in a direction of the thickness of the sheets stacked on said staple tray, and wherein said first facing face includes said limiting pressure member.

A sheet processing apparatus comprising:

• a staple tray having a sheet stacking face on which a sheet discharged from an image forming apparatus may be stacked;
• a rear end fence positioned to receive and vertically align a tail end of a sheet stacked on said staple tray, wherein said rear end fence includes a hitting face against which the sheet strikes, and a first facing face that faces the sheet stacking face of said staple tray;
• a pair of jogger fences that laterally align a sheet on said staple tray by contacting a side of the sheet perpendicular to a conveying direction of the sheet;
• a stapling device positioned to staple the vertically aligned tail ends of a bundle of at least two of the sheets stacked on said staple tray;
• and
• an elastic sheet guide member disposed so as to incline to press a portion of the tail end of the sheet toward one of said sheet stacking face of said staple tray and said first facing face.

A method for processing sheets, comprising the steps of:

• receiving sheets discharged from an image forming apparatus;
• guiding the sheets to a rear end fence of a staple tray;
• stacking the sheets on the staple tray;
• aligning the sheets laterally on the staple tray by contacting a side of the sheet perpendicular to a conveying direction of the sheet;
• aligning the sheets vertically by striking a tail end of the sheet against said rear end fence;
• pressing the tail ends of the sheets in a direction of thickness of the sheets;
• and
• stapling a bundle of the sheets at the tail ends of the sheets aligned by said rear end fence.