Sheet stacking apparatus, image forming system, and image forming apparatus

Abstract

A sheet stacking apparatus includes a conveying unit that stacks sheet stacks while sequentially shifting the sheet stacks by a feed amount in a substantially horizontal direction; and a feed amount changing unit that, when the conveying unit stacks the sheet stacks, is configured to change the feed amount at a job transition point based on various conditions.

1 . A sheet stacking apparatus comprising:
 a conveying unit that stacks sheet stacks while sequentially shifting the sheet stacks by a feed amount in a substantially horizontal direction; and   a feed amount changing unit that, when the conveying unit stacks the sheet stacks, is configured to change the feed amount at a job transition point.   
     
     
         2 . The sheet stacking apparatus according to  claim 1 , wherein each of the sheet stacks is center-folded. 
     
     
         3 . The sheet stacking apparatus according to  claim 1 , wherein each of the sheet stacks is saddle-stitched and center-folded. 
     
     
         4 . An image forming system comprising:
 an image forming apparatus that forms an image on a sheet;   a sheet processing apparatus that receives a plurality of sheets from the image forming apparatus, stacks a plurality of the sheets in a sheet stack, and performs a saddle-stitching and a center-folding on the sheet stack; and   a sheet stacking apparatus that includes
 a conveying unit that stacks sheet stacks processed in the sheet processing apparatus while sequentially shifting the sheet stacks by a feed amount in a substantially horizontal direction; and 
 a feed amount changing unit that, when the conveying unit stacks the sheet stacks, is configured to change the feed amount at a job transition point. 
   
     
     
         5 . The image forming system according to  claim 4 , wherein the feed amount changing unit changes the feed amount based on a signal from the image forming apparatus. 
     
     
         6 . The image forming system according to  claim 5 , wherein
 the image forming apparatus includes an operation panel, and   the image forming apparatus outputs the signal to the feed amount changing unit indicative of an instruction from the operation panel.   
     
     
         7 . The image forming system according to  claim 5 , wherein
 the image forming apparatus includes an operation panel, and   the image forming apparatus outputs the signal to the feed amount changing unit indicative of an instruction from the operation panel.   
     
     
         8 . The image forming system according to  claim 7 , wherein when the feed amount is set to change at the job transition point and when a size of sheets of the sheet stacks are different between jobs, the feed amount changing unit does not change the feed amount. 
     
     
         9 . The image forming system according to  claim 7 , wherein when the feed amount is set to change at the job transition point and when number of sheets of the sheet stacks are different between jobs, the feed amount changing unit does not change the feed amount. 
     
     
         10 . The image forming system according to  claim 8 , wherein the feed amount changing unit negates the signal when not changing the feed amount. 
     
     
         11 . The image forming system according to  claim 9 , wherein the feed amount changing unit negates the signal when not changing the feed amount. 
     
     
         12 . The image forming system according to  claim 4 , further comprising:
 a full-state sensor that detects a full state of the sheet stacking apparatus; and   a full-state setting unit that, when sheet stacks of a job is stacked on the sheet stacking apparatus, sets the full state by conveying the sheet stacks to a position where the full-state sensor detects the full state.   
     
     
         13 . An image forming apparatus comprising a sheet stacking apparatus including
 a conveying unit that stacks sheet stacks while sequentially shifting the sheet stacks by a feed amount in a substantially horizontal direction; and   a feed amount changing unit that, when the conveying unit stacks the sheet stacks, is configured to change the feed amount at a job transition point.