Post-processing apparatus and image forming system incorporating the post-processing apparatus

Abstract

A post-processing apparatus including a sheet bundle inserter, a movable sheet stacker, and a sheet binder. The sheet bundle inserter inserts a sheet bundle having multiple sheets overlapped on each other. The movable sheet stacker is inserted into and withdrawn from the sheet bundle inserter. The movable sheet stacker has a stacker face on which the sheet bundle is stacked. The sheet binder is in the sheet bundle inserter, and performs a sheet binding operation on the sheet bundle stacked on the movable sheet stacker.

What is claimed is: 
     
         1 . A post-processing apparatus comprising:
 a sheet bundle inserter configured to insert a sheet bundle having multiple sheets overlapped on each other;   a movable sheet stacker configured to be inserted into and withdrawn from the sheet bundle inserter, the movable sheet stacker having a stacker face on which the sheet bundle is stacked; and   a sheet binder in the sheet bundle inserter, the sheet binder configured to perform a sheet binding operation on the sheet bundle stacked on the movable sheet stacker.   
     
     
         2 . The post-processing apparatus according to  claim 1 ,
 wherein the stacker face of the movable sheet stacker is stackable, the sheet bundle including:
 a first sheet bundle having a first size smaller than an area of the stacker face, and 
 a second sheet bundle having a second size larger than the area of the stacker face, 
   the movable sheet stacker is drawn from the sheet bundle inserter to stack the first sheet bundle,   the movable sheet stacker stacking the first sheet bundle is inserted into the sheet bundle inserter, and   the sheet binder performs the sheet binding operation on the first sheet bundle on the movable sheet stacker inside the sheet bundle inserter.   
     
     
         3 . The post-processing apparatus according to  claim 1 ,
 wherein the stacker face of the movable sheet stacker is stackable, the sheet bundle including:
 a first sheet bundle having a first size smaller than an area of the stacker face, and 
 a second sheet bundle having a second size larger than the area of the stacker face, and 
   the movable sheet stacker is drawn from the sheet bundle inserter to stack a part of the second sheet bundle,   the movable sheet stacker, disposed outside the sheet bundle inserter, supports the second sheet bundle, and   the sheet binder performs the sheet binding operation on the second sheet bundle in the sheet bundle inserter while the movable sheet stacker outside the sheet bundle inserter supports the second sheet bundle.   
     
     
         4 . The post-processing apparatus according to  claim 2 ,
 wherein the movable sheet stacker includes:   a first contact portion to contact one end face of the first sheet bundle or the second sheet bundle; and   a second contact portion having a retractable portion to contact another end face of the first sheet bundle orthogonal to the one end face.   
     
     
         5 . The post-processing apparatus according to  claim 1 ,
 wherein the movable sheet stacker has a cutout portion at a position corresponding to a corner of the sheet bundle inserter when the movable sheet stacker is inserted into the sheet bundle inserter, and   the sheet binder performs the sheet binding operation at the position where the cutout portion of the movable sheet stacker is disposed.   
     
     
         6 . The post-processing apparatus according to  claim 5 ,
 wherein the movable sheet stacker includes an open-close member to move the cutout portion from an open position to a closed position when the movable sheet stacker is withdrawn from the sheet bundle inserter.   
     
     
         7 . The post-processing apparatus according to  claim 1 ,
 wherein the movable sheet stacker has a mark or a recess that indicates a position at which the sheet bundle is stacked on the stacker face.   
     
     
         8 . The post-processing apparatus according to  claim 1 ,
 wherein the movable sheet stacker includes a movable pressing member to press the sheet bundle stacked on the stacker face from above.   
     
     
         9 . The post-processing apparatus according to  claim 1 , further comprising a cover to cover an opening of the sheet bundle inserter,
 wherein the cover is placed on the opening of the sheet bundle inserter when the movable sheet stacker is inserted in the sheet bundle inserter.   
     
     
         10 . The post-processing apparatus according to  claim 1 , further comprising a sensor to detect whether the movable sheet stacker is inserted in the sheet bundle inserter,
 wherein the sheet binder automatically performs the sheet binding operation on the sheet bundle when the sensor detects that the movable sheet stacker with the sheet bundle stacked is inserted in the sheet bundle inserter.   
     
     
         11 . The post-processing apparatus according to  claim 1 , further comprising:
 a limitation mechanism to give a limitation to a withdrawal range of the movable sheet stacker from the sheet bundle inserter; and   a releasing mechanism to release the limitation by the limitation mechanism.   
     
     
         12 . The post-processing apparatus according to  claim 1 ,
 wherein the movable sheet stacker includes a retractable tray extending an area of the stacker face with the movable sheet stacker withdrawn from the sheet bundle inserter.   
     
     
         13 . An image forming system comprising:
 an image forming apparatus to form an image on a sheet; and   the post-processing apparatus according to  claim 1  to perform a given operation on the sheet.   
     
     
         14 . The image forming system according to  claim 13 ,
 wherein the image forming apparatus has an in-body space to which the sheet with the image is ejected and from which the sheet ejected from the image forming apparatus is removed, and   the post-processing apparatus is disposed in the in-body space of the image forming apparatus.   
     
     
         15 . A post-processing apparatus comprising:
 a sheet bundle container to accommodate an entire set of a sheet bundle;   a movable sheet stacker having a stacker face on which the sheet bundle, having a size smaller than an area of the stacker face, is placed, the movable sheet stacker being movable inside or outside the sheet bundle container; and   a sheet binder to perform a sheet binding operation on the sheet bundle in the sheet bundle container.   
     
     
         16 . The post-processing apparatus according to  claim 15 ,
 wherein the stacker face of the movable sheet stacker stacks the sheet bundle,   when the movable sheet stacker is outside the sheet bundle container, or   when the movable sheet stacker is inside the sheet bundle container.   
     
     
         17 . The post-processing apparatus according to  claim 15 ,
 wherein the stacker face of the movable sheet stacker is withdrawable in a direction orthogonal to a direction of gravity.   
     
     
         18 . An image forming system comprising:
 an image forming apparatus to form an image on a sheet; and   the post-processing apparatus according to  claim 15 ,   wherein the stacker face of the movable sheet stacker is withdrawable to a front side of the image forming apparatus.