Sheet separation method, sheet separation mechanism and sheet feeder

Abstract

Disclosed is a sheet separation method for separating a sheet one by one from a bundle of the sheets and feeding the separated sheet to a next processing step, including: suctioning an edge part of the sheet and pulling the suctioned edge part from the bundle as if to turn over the suctioned edge part; separating the sheet from the bundle, the edge part of the sheet being suctioned and pulled; and conveying the sheet separated from the bundle in a predetermined direction. A sheet separation mechanism and a sheet feeder are also disclosed.

1 . A sheet separation method for separating a sheet one by one from a bundle of the sheets and feeding the separated sheet to a next processing step, comprising:
 suctioning an edge part of the sheet and pulling the suctioned edge part from the bundle as if to turn over the suctioned edge part;   separating the sheet from the bundle, the edge part of the sheet being suctioned and pulled; and   conveying the sheet separated from the bundle in a predetermined direction.   
     
     
         2 . The sheet separation method according to  claim 1 , wherein the pulling includes:
 an up-and-down movement in which a suction head that suctions the edge part moves in a vertical direction to a surface of the bundle: and   a twist movement in which the suction head moves along a curved direction to the surface of the bundle.   
     
     
         3 . The sheet separation method according to  claim 1 , wherein the separating includes inserting at least one separation roller which moves along a surface of the bundle into a gap between the suctioned edge part of the sheet and the bundle. 
     
     
         4 . The sheet separation method according to  claim 3 , wherein a plate-like guide provided to the separation roller prevents the sheet separated from sagging. 
     
     
         5 . The sheet separation method according to  claim 3 , wherein the conveying includes rotating a conveying roller which sandwiches the separated sheet with the separation roller. 
     
     
         6 . A sheet separation mechanism for separating a sheet one by one from a bundle of the sheets and feeding the separated sheet to a next processing step, comprising:
 a suction/pulling unit including a suction head for suctioning an edge part of the sheet and pulling the suctioned edge part of the sheet apart from the bundle by a twist movement of the suction head;   a separation unit for separating the sheet from the bundle, the edge part of the sheet being suctioned and pulled by the suction head; and   a conveying unit for conveying the sheet separated from the bundle in a predetermined direction.   
     
     
         7 . The sheet separation mechanism according to  claim 6 , wherein the suction/pulling unit comprises:
 an up-and-down movement unit which moves the suction head to perform an up-and-down movement in a vertical direction to a surface of the bundle; and   a twist movement unit which moves the suction head to perform a twist movement along a curved direction to the surface of the bundle.   
     
     
         8 . The sheet separation mechanism according to  claim 6 , wherein the separation unit includes at least one separation roller which moves along a surface of the bundle, and
 the sheet is separated from the bundle by inserting the separation roller into a gap between the edge part of the sheet suctioned and pulled by the suction/pulling unit and the bundle.   
     
     
         9 . The sheet separation mechanism according to  claim 8 , wherein the separation roller includes a plate-like guide for preventing the sheet separated from the bundle by the suction/pulling unit from sagging. 
     
     
         10 . The sheet separation mechanism according to  claim 8 , wherein the conveying unit includes a conveying roller which sandwiches the separated sheet with the separation roller, and the sheet separated from the bundle is conveyed in a predetermined direction by a rotation of the conveying roller on its axis. 
     
     
         11 . A sheet separation mechanism for separating a sheet one by one from a bundle of the sheets and feeding the separated sheet to a next processing step, comprising:
 suction/pulling means including a suction head for suctioning an edge part of the sheet and pulling the suctioned edge part of the sheet apart from the bundle by a twist movement of the suction head;   separation means for separating the sheet from the bundle, the edge part of the sheet being suctioned and pulled by the suction head; and   conveying means for conveying the sheet separated from the bundle in a predetermined direction.   
     
     
         12 . A sheet feeder comprising a sheet conveying mechanism which conveys a bundle of sheets and a sheet separation mechanism which separates the sheet one by one from the bundle that is conveyed to an end part of the sheet conveying mechanism and feeds the separated sheet to a next processing step, wherein the sheet separation mechanism comprises:
 a suction/pulling unit including a suction head for suctioning an edge part of the sheet and pulling the suctioned edge part of the sheet apart from the bundle by a twist movement of the suction head;   a separation unit for separating the sheet from the bundle, the edge part of the sheet being suctioned and pulled by the suction head; and   a conveying unit for conveying the sheet separated from the bundle in a predetermined direction.   
     
     
         13 . The sheet feeder according to  claim 12 , wherein the sheet conveying mechanism comprises:
 an upright position maintaining/conveying unit which conveys the bundle placed on a mounting table toward the sheet separation mechanism while maintaining an upright position of the bundle; and   a posture controlling/conveying unit which controls a posture of the bundle before reaching the sheet separation mechanism while conveying the bundle toward the sheet separation mechanism.