Sheet discharging device and sheet discharging method

Abstract

A sheet discharging device includes a guide member including a guide surface on which a conveyed sheet is guided, a plurality of sheet discharging rollers, which have an axis, arranged on a guide surface side of the guide member at intervals in a direction crossing a direction in which the sheet is conveyed, the sheet discharging rollers discharging the sheet guided on the guide surface, a sheet discharging tray on which sheets discharged by the sheet discharging rollers are stacked, and a plurality of projecting portions provided on the guide member and projecting from a plane on which the sheet discharging rollers contact the sheet, toward the axis of the sheet discharging rollers, to partly raise the sheet toward the axis of the sheet discharging rollers.

1 . A sheet discharging device comprising: 
 a guide member comprising a guide surface on which a conveyed sheet is guided;    a plurality of sheet discharging rollers, which have an axis, arranged on a guide surface side of the guide member at intervals in a direction crossing a direction in which the sheet is conveyed, the sheet discharging rollers discharging the sheet guided on the guide surface;    a sheet discharging tray on which sheets discharged by the sheet discharging rollers are stacked; and    a plurality of projecting portions provided on the guide member and projecting from a plane on which the sheet discharging rollers contact the sheet, toward the axis of the sheet discharging rollers, to partly raise the sheet toward the axis of the sheet discharging rollers.    
     
     
         2 . The sheet discharging device according to  claim 1 , wherein each of the projecting portions is placed near a corresponding one of the sheet discharging rollers.  
     
     
         3 . The sheet discharging device according to  claim 1 , wherein each of the projecting portions has a first inclined surface formed in an area of the projecting portion which is located upstream of the sheet discharging roller in the conveying direction of the sheet, the first inclined surface being more separate from a plane defined by the guide surface as the first inclined surface approaches its end in the conveying direction of the sheet.  
     
     
         4 . The sheet discharging device according to  claim 3 , wherein each of the projecting portions has a second inclined surface formed in an area of the projecting portion which corresponds to the sheet discharging roller in the conveying direction of the sheet, the second inclined surface being more separate from the plane defined by the guide surface as the second inclined surface approaches its end in the conveying direction of the sheet, the second inclined surface being gentler than the first inclined surface.  
     
     
         5 . The sheet discharging device according to  claim 1 , wherein a distance between the plane defined by the guide surface and the axis of sheet discharging rollers is larger than a radius of the sheet discharging roller.  
     
     
         6 . The sheet discharging device according to  claim 1 , further comprising: 
 a pinch roller which is brought into pressure contact with at least one of the sheet discharging rollers.    
     
     
         7 . The sheet discharging device according to  claim 1 , wherein the sheet discharging device is applied to an auto document feeder.  
     
     
         8 . A method for discharging a sheet, the method comprising: 
 guiding a conveyed sheet along a guide surface to a sheet discharging tray; and    allowing projecting portions provided on the guide surface to raise at least a part of the guided sheet in a direction in which the sheet is separated from the guide surface.