Post-processing apparatus and image forming system

Abstract

A post-processing apparatus having therein a stacker that stocks sheets temporarily and an ejection device that ejects a plurality of sheets stacked on the stacker from the stacker wherein the ejection device has an ejection claw that pushes up the plural sheets and a moving device that moves the ejection claw along the stacker, the ejection claw has a contact surface with which the aforesaid plural sheets are brought into contact when the plural sheets are pushed up, and the contact surface has plural protrusions protruding toward the plural sheets.

1 . A post-processing apparatus comprising:
 a stacker which stocks a sheet temporarily; and   an ejection device which ejects a plurality of sheets from the stacker on which the plurality of sheets have been stacked,   the ejection device comprising:   an ejection claw which pushes up the plurality of sheets; and   a moving device which moves the ejection claw along the stacker,   wherein the ejection claw comprises a contact surface with which the plurality of sheets are brought into contact when the ejection claw moves and pushes up the plurality of sheets by the moving device, and the contact surface comprises a plurality of protrusions which protrudes toward the plurality of sheets stacked on the stacker.   
     
     
         2 . The post-processing apparatus of  claim 1 ,
 wherein the plurality of protrusions extend parallel to a width direction of the plurality of sheets stacked on the stacker.   
     
     
         3 . The post-processing apparatus of  claim 2 ,
 wherein the ejection claw is fixed to the moving device and at least a lateral surface facing the moving device among both lateral surfaces of each of the plurality of protrusions makes a prescribed angle with a bottom surface of a recess between the plurality of protrusions adjacent to each other, the recess being adjacent to the lateral surface.   
     
     
         4 . The post-processing apparatus of  claim 1 ,
 wherein the ejection device comprises a plurality of the moving devices arranged in a direction perpendicular to an ejection direction of the plurality of sheets stacked on the stacker.   
     
     
         5 . The post-processing apparatus of  claim 1 ,
 wherein a protrusion positioned at an uppermost portion of the ejection claw among the plurality of protrusions is taller than another protrusion of the plurality of protrusions.   
     
     
         6 . An image forming system comprising:
 an image forming apparatus which conducts image forming on a sheet; and   a post-processing apparatus of  claim 1  connected to the image forming apparatus.   
     
     
         7 . The image forming system of  claim 6 ,
 wherein the image forming apparatus comprises a selecting device which selects a post-processing operation to be conducted in the post-processing apparatus.   
     
     
         8 . The image forming system of  claim 7 ,
 wherein each of the image forming apparatus and the post-processing apparatus comprises an information communicating device for communicating information about the post-processing operation selected by the selecting device.