Sheet finishing apparatus

Abstract

According to an aspect of the invention, a shifter shifts sheets before stapling in a continuous stapling mode. A bundle of sheets is immediately discharged from the shifter after the stapling. In a sorting mode, the bundle of sheets is discharged from the shifter while the bundle of sheets is shifted in a direction perpendicular to a discharge direction of the bundle of sheets. A friction force applied to a bundle of sheet T in the discharging is distributed in the discharge direction and a direction perpendicular to the discharge direction.

1 . A sheet finishing apparatus comprising:
 a processing tray which stacks a plurality of sheets;   a processing member which finishes the sheets;   a receiving member which receives the plurality of sheets discharged from the processing tray in a discharge direction; and   a sheet transporting member which transports the plurality of sheets from the processing tray to the receiving member while shifting the plurality of sheets in a direction perpendicular to the discharge direction.   
     
     
         2 . The apparatus according to  claim 1 , wherein the sheet transporting member transports a first plurality of sheets from the processing tray to the receiving member while shifting the first plurality of sheets in a first direction, and transports a second plurality of sheets from the processing tray to the receiving member while shifting the second plurality of sheets in a second direction opposite to the first direction. 
     
     
         3 . The apparatus according to  claim 2 , wherein the first direction and the second direction are perpendicular to the discharge direction. 
     
     
         4 . The apparatus according to  claim 1 , wherein the processing member includes a shifter which shifts the sheets supplied to the processing tray in the direction perpendicular to the discharge direction. 
     
     
         5 . The apparatus according to  claim 4 , wherein the shifter includes a transverse alignment member which aligns ends of the plurality of sheets stacked on the processing tray in the direction perpendicular to the discharge direction. 
     
     
         6 . The apparatus according to  claim 1 , wherein the processing member includes a stapler which staples the plurality of sheets stacked on the processing tray. 
     
     
         7 . The apparatus according to  claim 1 , wherein the sheet transporting member shifts the sheets having a size longer in the discharge direction than a predetermined size, and does not shift the sheets having a size shorter in the discharge direction than the predetermined size. 
     
     
         8 . The apparatus according to  claim 1 , wherein the sheet transporting member shifts the sheets having weight lighter than a predetermined basis weight in the direction perpendicular to the discharge direction and does not shift the sheets having a weight heavier than the predetermined basis weight in the direction perpendicular to the discharge direction. 
     
     
         9 . The apparatus according to  claim 1 , wherein the sheet transporting member includes a travel member and a transverse alignment member. 
     
     
         10 . An image forming apparatus comprising:
 an image forming member which forms an image on a sheet;   a processing tray which stacks a plurality of the sheets supplied from the image forming member;   a processing member which finishes the sheets;   a receiving member which receives the plurality of sheets discharged from the processing tray; and   a sheet transporting member which transports the plurality of sheets from the processing tray to the receiving member while shifting the plurality of sheets in a direction perpendicular to the discharge direction.   
     
     
         11 . The apparatus according to  claim 10 , wherein the sheet transporting member transports a first plurality of sheets from the processing tray to the receiving member while shifting the first plurality of sheets in a first direction, and transports a second plurality of sheets from the processing tray to the receiving member while shifting the second plurality of sheets in a second direction opposite to the first direction. 
     
     
         12 . The apparatus according to  claim 11 , wherein the first direction and the second direction are perpendicular to the discharge direction. 
     
     
         13 . The apparatus according to  claim 10 , wherein the processing member includes a shifter which shifts the sheets supplied to the processing tray in the direction perpendicular to the discharge direction. 
     
     
         14 . The apparatus according to  claim 13 , wherein the shifter includes a transverse alignment member which aligns ends of the plurality of sheets stacked on the processing tray in the direction perpendicular to the discharge direction. 
     
     
         15 . The apparatus according to  claim 10 , wherein the processing member includes a stapler which staples the plurality of sheets stacked on the processing tray. 
     
     
         16 . The apparatus according to  claim 10 , wherein the sheet transporting member shifts the sheets, which has a size longer in the discharge direction than a predetermined size, in the direction perpendicular to the discharge direction. 
     
     
         17 . The apparatus according to  claim 10 , wherein the sheet transporting member shifts the sheets having a size longer in the discharge direction than a predetermined size, and does not shift the sheets having a size shorter in the discharge direction than the predetermined size. 
     
     
         18 . The apparatus according to  claim 10 , wherein the sheet transporting member includes a travel member and a transverse alignment member. 
     
     
         19 . A sheet finishing method comprising:
 stacking sheets in a processing tray;   discharging the plurality of sheets stacked in the processing tray from the processing tray, while shifting the sheets in a direction perpendicular to a discharge direction of the sheets; and   stacking the plurality of sheets discharged from the processing tray.   
     
     
         20 . The method according to  claim 19 , further comprising:
 shifting the sheets supplied to the processing tray in the same direction as a shift direction in the discharging.