Document sheet conveying apparatus

Abstract

A document sheet conveying unit of the invention comprises a casing in which are mounted an active roller, a plurality of idle rollers, and at least a guide element. The idle rollers are mounted in a manner to be respectively in circumferential contact with the active roller. The guide element is mounted proximate to one of the idle rollers, and has a guide surface with a prolonged plane that is tangent with the corresponding idle roller at its contact point with the active roller. The guide surface thereby orients and guides the document sheet to adequately engage through the active roller and corresponding idle roller. Jam of the document sheet is therefore prevented.

1 . A document sheet conveying unit for conveying document sheet, comprising: 
 a casing;    an active roller, mounted inside the casing;    a plurality of idle rollers, mounted in the casing a manner to be in circumferential contact with the active roller to convey the document sheet along a sheet conveyance path; and    at least a guide element, placed proximate to one of the idle rollers, the guide element having a guide surface that guides the engagement of the document sheet through the corresponding idle roller and active roller along the sheet conveyance path.    
     
     
         2 . The document sheet conveying unit of  claim 1 , wherein a prolonged plane of the guide surface is tangent with the corresponding idle roller and active roller at the contact point there between.  
     
     
         3 . The document sheet conveying unit of  claim 2 , wherein the guide surface is a plane.  
     
     
         4 . The document sheet conveying unit of  claim 2 , wherein the guide surface is a curved surface.  
     
     
         5 . The document sheet conveying unit of  claim 1 , wherein the guide element is formed with an inner surface of the casing in a single body.  
     
     
         6 . The document sheet conveying unit of  claim 1 , wherein the guide element has a triangular shape.  
     
     
         7 . The document sheet conveying unit of  claim 1 , wherein the sheet conveyance path terminates respectively in a sheet intake end through which the document sheet is introduced in the document sheet conveying unit, and a sheet release end through which the document sheet is released from the document sheet conveying unit.  
     
     
         8 . The document sheet conveying unit of  claim 7 , wherein the sheet intake end and the sheet release end are located on a same side relative to the active roller.  
     
     
         9 . The document sheet conveying unit of  claim 7 , further including the assembly of a sheet-separating plate and a sheet-separating roller in contact with the sheet-separating plate, the sheet-separating plate and the sheet-separating roller being placed on the sheet conveyance path between the active roller and the sheet intake end.  
     
     
         10 . The document sheet conveying unit of  claim 9 , further including sheet intake roller mounted on the sheet conveyance path between the sheet intake end and the assembly of the sheet-separating plate and sheet-separating roller.