Sheet post-processing apparatus

Abstract

A sheet post-processing apparatus includes a sheet conveyance passage along which a sheet is conveyed and a driving roller and a driven roller that are arranged opposite each other across a folding conveyance passage branching off the sheet conveyance passage and that are kept in pressed contact with each other. The sheet post-processing apparatus double-folds the sheet passing through a nip portion between the driving and driven rollers and conveys the double-folded sheet. The nip portion is formed with one of the driving and driven rollers pivoting about a pivoting shaft to be pressed against the other. To one of the rotation shaft of the driving roller and the pivoting shaft, the driving shaft of the driving motor is directly coupled. The other of the rotation shaft of the driving roller and the pivoting shaft is coupled to the driving shaft via a driving transmission gear.

What is claimed is: 
     
         1 . A sheet post-processing apparatus, comprising:
 a sheet conveyance passage along which a sheet is conveyed; and   a driving roller and a driven roller that are arranged opposite each other across a folding conveyance passage branching off the sheet conveyance passage, the driving roller and the driven roller being kept in pressed contact with each other,   the sheet post-processing apparatus double-folding the sheet passing through a nip portion formed between the driving roller and the driven roller, the sheet post-processing apparatus then conveying the double-folded sheet,   wherein   the nip portion is formed as a result of one of the driving roller and the driven roller pivoting about a pivoting shaft so as to be pressed against the other,   to one of a rotation shaft of the driving roller and the pivoting shaft, a driving shaft of a driving motor is directly coupled, and   the other of the rotation shaft of the driving roller and the pivoting shaft is coupled to the driving shaft via a driving transmission gear.   
     
     
         2 . The sheet post-processing apparatus according to  claim 1 , wherein
 the driving shaft of the driving motor is positioned with respect to the pivoting shaft.   
     
     
         3 . The sheet post-processing apparatus according to  claim 1 , wherein
 a plurality of driven rollers are provided for one driving roller to form a plurality of nip portions,   a plurality of driving motors are provided,   the driven rollers pivot with respect to the driving roller, and   to the pivoting shaft, driving shafts of the driving motors are directly coupled.