Sheet processing apparatus and image forming apparatus

Abstract

The front ends of the plurality of sheets stacked on the processing tray are abutted against the stopper and are reliably aligned. The stack of a predetermined number of sheets to be accommodated in the processing tray is aligned and stacked all at once in the processing tray while being simultaneously gripped by the gripping portion 5 a of the movement gripper in a plurality of sheet groups. The temporal margin is thereby produced compared to when aligning and stacking are performed one sheet at a time, and thus is effective in realizing the high speed process at low cost and maintaining high productivity.

1 . A sheet processing apparatus comprising: 
 a sheet conveying portion which conveys a sheet;    a sheet moving unit which includes a gripping portion capable of gripping the ends of the plurality of sheets conveyed by the sheet conveying portion, and moves the sheets by moving the gripping portion while gripping the sheets;    a sheet abutment member which is abutted with the ends of the sheet moved by the sheet moving unit; and    a processing tray which stacks the sheets moved by the sheet moving unit and performs processes thereon;    wherein the sheet moving unit releases the plurality of sheets from the gripping portion by abutting the ends of the plurality of gripped sheets to the sheet abutment member, and accommodates the plurality of sheets into the processing tray.    
   
   
       2 . The sheet processing apparatus according to  claim 1 , wherein the plurality of sheets gripped by the gripping portion are accommodated in the processing tray over a predetermined number of times to form a sheet bundle made up of a predetermined number of sheets in the processing tray.  
   
   
       3 . The sheet processing apparatus according to  claim 2 , wherein the number of sheets first gripped by the gripping portion so as to form the next sheet bundle, while the sheet bundle stacked on the processing tray is being processed, is greater than the number of sheets to be subsequently gripped.  
   
   
       4 . The sheet processing apparatus according to  claim 2 , wherein when the number of sheets gripped last by the gripping portion so as to form the sheet bundle is determined as one, the number of sheets to be gripped before is increased by one sheet.  
   
   
       5 . The sheet processing apparatus according to  claim 1 , wherein after the gripping portion grips a sheet at a predetermined receiving position and the sheet moving unit guides the gripped sheet to the movement path by moving the gripping portion in the moving direction, the gripping portion is moved to the receiving position in the direction opposite the moving direction to grip the next sheet in a superimposed manner.  
   
   
       6 . The sheet processing apparatus according to  claim 5 , further comprising: 
 a retreating portion for the sheet gripped by the gripping portion, which is provided to prevent interference with the sheet to be gripped next when the gripping portion is moved to the receiving position in the direction opposite to the moving direction.    
   
   
       7 . The sheet processing apparatus according to any one of  claims 1  to  6 , wherein the sheet moving unit is a rotating drum that moves the sheets wrapped around an outer periphery, and has the gripping portion provided with elasticity at one part of the outer periphery.  
   
   
       8 . The sheet processing apparatus according to any one of  claims 1  to  6 , further comprising an aligning portion which aligns the ends of the sheet in the direction orthogonal to the moving direction each time the plurality of sheets is accommodated in the processing tray.  
   
   
       9 . The sheet processing apparatus according to any one of  claims 1  to  6 , further comprising a post-processing unit which performs processes on the sheet bundle stacked on the processing tray.  
   
   
       10 . A sheet processing apparatus comprising: 
 a sheet conveying portion which conveys a sheet;    a sheet moving unit which includes a gripping portion capable of gripping the ends of the plurality of sheets conveyed by the sheet conveying portion, and moves the sheets by moving the gripping portion while gripping the sheets;    a sheet abutment member which is abutted with the ends of the sheets moved by the sheet moving unit;    a processing tray which stacks the sheets moved by the sheet moving unit and performs processes thereon; and    an aligning portion which aligns the ends of the sheet in the direction orthogonal to the moving direction each time the plurality of sheets is accommodated in the processing tray;    wherein the sheet moving unit releases the plurality of sheets from the gripping portion by abutting the ends of the plurality of gripped sheets to the sheet abutment member, and accommodates the plurality of sheets in the processing tray; and    the aligning portion performs alignment each time the plurality of sheets are accommodated in the processing tray.    
   
   
       11 . The sheet processing apparatus according to  claim 10 , wherein the sheet moving unit performs alignment in the moving direction by abutting the ends of the plurality of sheets gripped by the gripping portion against the sheet abutment member.  
   
   
       12 . An image forming apparatus comprising: 
 an image forming portion which forms an image on the sheet; and    the sheet processing apparatus according to any one of  claims 1  to  6  or  10  and  11 .