Sheet post-processing apparatus

Abstract

The disclosure concerns a standby tray for making a sheet at the position above a processing tray. The sheet on the standby tray is dropped and supplied onto the processing tray. The upper end of the center area of a shutter supporting the rear end of the sheet on a sheet discharge tray which is slidable to the sheet discharge section of the standby tray or processing tray is made lower than the upper end of the peripheral area of the shutter. Movable portions of the shutter are extended when the sheet discharge tray is slid to close the sheet discharge sections of the processing tray and/or standby tray.

1 . (canceled) 
     
     
         2 . A sheet post-processing apparatus comprising:
 a processing tray to support a sheet discharged from an image forming apparatus;   a processing mechanism to perform post-processing for the sheet;   a sheet discharge tray to load the sheet, the sheet discharge tray tilted such that the discharge direction front end of the sheet is positioned higher than the discharge direction rear end thereof;   a discharge mechanism to discharge the sheet from the processing tray to the sheet discharge tray; and   a rear end supporting mechanism which height of an upper end of a center area of the rear end supporting mechanism is lower than an upper end of peripheral area of the rear end supporting mechanism and which slides in a vertical direction at the discharge direction rear end of the sheet on the sheet discharge tray.   
     
     
         3 . The apparatus according to  claim 2 , wherein the sheet discharge tray moves to the vertical direction and the rear end supporting mechanism slides along with the move of the sheet discharge tray. 
     
     
         4 . The apparatus according to  claim 3 , wherein the rear end supporting mechanism closes a sheet discharge section of the sheet discharge tray if the sheet discharge tray moves to the vertical direction. 
     
     
         5 . The apparatus according to  claim 2 , wherein the sheet discharge tray includes an upper sheet discharge tray and a lower sheet discharge tray. 
     
     
         6 . The apparatus according to  claim 2 , further comprising a standby tray which is arranged over the processing tray to stand by the sheet discharge from an image forming apparatus. 
     
     
         7 . The apparatus according to  claim 6 , wherein the sheet discharge tray moves to the vertical direction until to a sheet discharge section if the sheet is discharged from the standby tray to the sheet discharge tray, and the rear end supporting mechanism slides along with the move of the sheet discharge tray to closes a sheet discharge section of the sheet discharge tray. 
     
     
         8 . The apparatus according to  claim 6 , wherein the standby tray includes a pair of trays to support the both sides of the sheet, and the stand by tray drop and supply the sheet onto the processing tray between the pair of trays. 
     
     
         9 . The apparatus according to  claim 2 , further comprising a center alignment roller which is arranged at one end of the processing tray on the sheet discharge tray side and rotates in the forward direction or reverse direction and a slide alignment roller which shaft is same of the center alignment roller, and which are arranged on both sides of the center alignment roller, and rotate in the forward direction or reverse direction. 
     
     
         10 . The apparatus according to  claim 9 , wherein the center area of the rear end supporting mechanism is an area that faces to the center alignment roller. 
     
     
         11 . The apparatus according to  claim 9 , wherein the discharge mechanism is a carrier belt and the center alignment roller is a pair of center alignment rollers which are disposed symmetrically with respect to the conveyor belt.