Paper discharge device and image forming apparatus

Abstract

It is an object of the present invention to provide a paper discharge device that can sort sheets on a tray. The paper discharge device has paper discharge rollers, a tray and a driving mechanism. The paper discharge rollers are configured to discharge a sheet having an image formed thereon. The tray is configured to be stacked with the sheet discharged from the paper discharge rollers. The driving mechanism is configured to move the tray in a direction approaching the paper discharge rollers and a direction away from the paper discharge rollers and vary a stacking position of the sheet on the tray.

1 . A paper discharge device comprising;
 a stacker configured to stack sheets finally discharged from paper discharge rollers;   a contact member configured to come into contact with the sheets stacked on the stacker; and   a driving mechanism configured to move the contact member to vary a stacking position of the sheet on the stacker.   
     
     
         2 . The paper discharge device according to  claim 1 ,
 wherein the contact member is a roller configured to come into contact with the sheets stacked on the stacker and move the sheets to positions different from each other on the stacker according to rotating operation; and   the driving mechanism moves the roller in a direction approaching the stacker and a direction away from the stacker.   
     
     
         3 . The paper discharge device according to  claim 2 , wherein the driving mechanism rotates the roller around an axis orthogonal to a stacking surface of the stacker. 
     
     
         4 . The paper discharge device according to  claim 3 , wherein the driving mechanism moves the roller in the direction approaching the stacker and brings the roller into contact with the sheets after rotating the roller around the axis. 
     
     
         5 . The paper discharge device according to  claim 1 , wherein the driving mechanism stops the contact member in a position away from the stacker when a sheet is discharged from the paper discharge rollers. 
     
     
         6 . The paper discharge device according to  claim 2 , wherein the roller moves the sheets to the positions different from each other on the stacker by switching a rotating direction. 
     
     
         7 . The paper discharge device according to  claim 2 , wherein the driving mechanism changes the orientation of the roller in accordance with a moving direction of the sheets. 
     
     
         8 . The paper discharge device according to  claim 2 , wherein the roller is arranged in a center of the stacker when viewed from a direction orthogonal to a stacking surface of the stacker. 
     
     
         9 . The paper discharge device according to  claim 1 , wherein the sheets in the positions different from each other on the stacker partially overlap each other when viewed from a direction orthogonal to a stacking surface of the stacker. 
     
     
         10 . The paper discharge device according to  claim 2 , wherein the driving mechanism includes:
 an arm configured to support the roller at a distal end of the arm; and   a supporting member configured to support a proximal end of the arm, wherein   the driving mechanism moves the roller in the direction   approaching the stacker and the direction away from the stacker by rotating the arm.   
     
     
         11 . The paper discharge device according to  claim 10 , wherein the supporting member rotates around an axis orthogonal to a stacking surface of the stacker. 
     
     
         12 . The paper discharge device according to  claim 1 , wherein the driving mechanism moves the contact member in a direction approaching the stacker and a direction away from the stacker and moves the contact member along a stacking surface of the stacker. 
     
     
         13 . The paper discharge device according to  claim 12 , wherein the contact member is a roller that moves the sheets along the stacker according to rotating operation. 
     
     
         14 . The paper discharge device according to  claim 13 , wherein the roller moves the sheets to positions different from each other on the stacker by switching a rotating direction. 
     
     
         15 . The paper discharge device according to  claim 2 , wherein the driving mechanism moves the roller along the stacking surface of the stacker without rotating the roller to move the sheets to positions different from each other. 
     
     
         16 . The paper discharge device according to  claim 12 , wherein
 the driving mechanism moves the contact member from an initial position, and   the contact member in the initial position is located in a center of the stacker when viewed from a direction orthogonal to the stacking surface of the stacker.   
     
     
         17 . The paper discharge device according to  claim 12 , wherein the driving mechanism includes:
 an arm configured to support the contact member at a distal end of the arm; and   a slide member configured to support a proximal end of the arm and moves in one direction in a plane orthogonal to the stacking surface of the stacker.   
     
     
         18 . An image forming apparatus comprising:
 an image forming unit configured to form an image on a sheet; and   a paper discharge device configured to be located above the image forming unit and including a stacker configured to stack sheets finally discharged from paper discharge rollers, a contact member configured to come into contact with the sheets stacked on the stacker, and a driving mechanism configured to move the contact member to vary a stacking position of the sheet on the stacker.   
     
     
         19 . The image forming apparatus according to  claim 18 , wherein the driving mechanism moves, for each print job, sheets to positions different from each other on the stacker. 
     
     
         20 . A paper discharge method comprising:
 stacking sheets finally discharged from paper discharge rollers on a stacker;   contacting a contact member with the sheets stacked on the stacker; and   moving the contact member by a driving mechanism to vary a stacking position of the sheet on the stacker.