Sheet feed apparatus and sheet feed method

Abstract

Provided is a sheet feed apparatus including: a loading unit loaded with a sheet stack including sheets; a feed unit that comes into contact with a surface of the uppermost sheet of the sheet stack and feeds the sheet in a feed direction; and a separation mechanism that jets out air to sheets to separate the sheets in a height direction, the separation mechanism has a first jetting unit that jets out air to a first region including a downstream end of the uppermost sheet and a second jetting unit that jets out air to a second region of the sheet stack below the first region, the first jetting unit jets out air such that a first jetting direction to the first region varies, and the second jetting unit jets out air in a second jetting direction directed to the second region and set independently of the first jetting direction.

What is claimed is: 
     
         1 . A sheet feed apparatus comprising:
 a loading unit configured to be loaded with a sheet stack including sheets;   a feed unit configured to come into contact with a surface of the uppermost sheet of the sheet stack and feed the sheet in a feed direction; and   at least one first separation mechanism configured to jet out air to a plurality of sheets including the uppermost sheet of the sheet stack to separate the plurality of sheets in a height direction,   wherein the first separation mechanism has   a first jetting unit configured to jet out air to a first region including a downstream end in the feed direction of the uppermost sheet of the sheet stack, and   a second jetting unit configured to jet out air to a second region of the sheet stack, the second region being below the first region in the height direction,   wherein the first jetting unit jets out air such that a first jetting direction directed to the first region varies, and   wherein the second jetting unit jets out air in a second jetting direction directed to the second region and set independently of the first jetting direction.   
     
     
         2 . The sheet feed apparatus according to  claim 1 , wherein the second jetting unit fixes the second jetting direction to a constant direction and jets out air. 
     
     
         3 . The sheet feed apparatus according to  claim 1 ,
 wherein the first jetting unit jets out air such that the first jetting direction oscillates in the height direction,   wherein the second jetting unit jets out air such that the second jetting direction oscillates in the height direction, and   wherein a first motion direction in the height direction of the tip of the first jetting unit is set to an opposite direction to a second motion direction in the height direction of the tip of the second jetting unit.   
     
     
         4 . The sheet feed apparatus according to  claim 1 , wherein a plurality of first separation mechanisms are arranged at a plurality of positions along a width direction orthogonal to the feed direction of the sheets fed by the feed unit. 
     
     
         5 . The sheet feed apparatus according to  claim 4 , wherein a pair of the first separation mechanisms are arranged at positions symmetrical with respect to the center position in the width direction of the sheet stack. 
     
     
         6 . The sheet feed apparatus according to  claim 5  further comprising a second separation mechanism configured to jet out air to the plurality of sheets including the uppermost sheet of the sheet stack to separate the plurality of sheets in the height direction,
 wherein the second separation mechanism is arranged at a more distant position from the center position than the first separation mechanism. 
 
     
     
         7 . The sheet feed apparatus according to  claim 1 , wherein the first separation mechanism has
 an air supply path supplied with air,   a partition plate that partitions air supplied from the air supply path into the first jetting unit and the second jetting unit at a predetermined position in the height direction, and   a deflection plate that causes a flowing direction of air guided to the first jetting unit to vary in the height direction.   
     
     
         8 . The sheet feed apparatus according to  claim 1 , wherein the feed unit has
 a driving roller,   a driven roller,   a feed belt stretched around the driving roller and the driven roller, suction holes being formed in the feed belt, and   a suction unit configured to suck air through the suction holes formed in the feed belt passing by a position facing the sheet stack.   
     
     
         9 . The sheet feed apparatus according to  claim 1 , wherein when the sheets are viewed in planar view, the first jetting unit jets out air in a direction to an edge arranged at a downstream end in the feed direction of the sheets, the direction being opposite to the feed direction. 
     
     
         10 . The sheet feed apparatus according to  claim 1 , wherein when the sheets are viewed in planar view, the first jetting unit jets out air in a direction to an edge arranged parallel to the feed direction of the sheets, the direction intersecting the feed direction. 
     
     
         11 . A sheet feed method for feeding sheets by a sheet feed apparatus, wherein the sheet feed apparatus comprises
 a loading unit configured to be loaded with a sheet stack including sheets,   a feed unit configured to come into contact with a surface of the uppermost sheet of the sheet stack and feed the sheet in a feed direction, and   at least one first separation mechanism configured to jet out air to a plurality of sheets including the uppermost sheet of the sheet stack to separate the plurality of sheets in a height direction, and   wherein the first separation mechanism has   a first jetting unit configured to jet out air to a first region including a downstream end in the feed direction of the uppermost sheet of the sheet stack, and   a second jetting unit configured to jet out air to a second region of the sheet stack, the second region being below the first region in the height direction,   the sheet feed method comprising:   a first jetting step of jetting out air such that a first jetting direction directed from the first jetting unit to the first region varies;   a second jetting step of jetting out air in a second jetting direction directed from the second jetting unit to the second region and set independently of the first jetting direction; and   a feeding step of feeding the sheet in the feed direction by the feed unit in a state where air is jetted to the first region in the first jetting step and air is jetted to the second region in the second jetting step.   
     
     
         12 . The sheet feed method according to  claim 11 , wherein the second jetting step includes fixing the second jetting direction to a constant direction and jetting out air. 
     
     
         13 . The sheet feed method according to  claim 11 ,
 wherein the first jetting step includes jetting out air such that the first jetting direction oscillates in the height direction,   wherein the second jetting step includes jetting out air such that the second jetting direction oscillates in the height direction, and   wherein a first motion direction in the height direction of the tip of the first jetting unit is set to an opposite direction to a second motion direction in the height direction of the tip of the second jetting unit.