Sheet feeding device and image forming apparatus

Abstract

A sheet feeding device including a belt including a dielectric material seamlessly wound about rollers and disposed opposite a top surface of a stack of multiple sheets placed on a sheet storage stand to attract a sheet from the stack of multiple sheets and convey the sheet, and a charger to form a predetermined charge pattern on a surface of the belt. A shaft of one of the rollers provided downstream from the other roller in a direction of sheet feed serves as a pivot of the belt about which the belt swings, and the belt swings around the pivot such that the surface of the belt facing the top surface of the stack of multiple sheets and a surface of the sheet storage stand facing the surface of the belt are substantially parallel to each other.

1 . A sheet feeding device, comprising:
 a belt comprising a dielectric material seamlessly wound about rollers and disposed opposite a top surface of a stack of multiple sheets placed on a sheet storage stand to attract a sheet from the stack of multiple sheets and convey the sheet; and   a charger to form a predetermined charge pattern on a surface of the belt,   wherein:   a shaft of one of the rollers provided downstream from the other roller in a direction of sheet feed serves as a pivot of the belt about which the belt swings; and   the belt swings around the pivot such that the surface of the belt facing the top surface of the stack of multiple sheets and a surface of the sheet storage stand facing the surface of the belt are substantially parallel to each other.   
     
     
         2 . The sheet feeding device according to  claim 1 , wherein a leading edge of the stack of multiple sheets is positioned opposite a bottom part of a curved portion of the belt on a downstream side relative to the direction of sheet feed. 
     
     
         3 . The sheet feeding device according to  claim 1 , wherein the charger is provided adjacent to the pivot of the belt. 
     
     
         4 . The sheet feeding device according to  claim 1 , wherein a pivot-side roller around which the belt is wound is rotatably driven. 
     
     
         5 . The sheet feeding device according to  claim 1 , further comprising an upper guide plate provided downstream from a leading edge side of the stack of multiple sheets placed on a sheet storage stand in the direction of sheet feed,
 wherein a surface of a curved portion of the belt provided downstream in the direction of sheet feed intersects with the upper guide plate.   
     
     
         6 . The sheet feeding device according to  claim 1 , further comprising a biasing member to lift a free edge of the belt opposite an end of the belt at the pivot. 
     
     
         7 . The sheet feeding device according to  claim 1 , further comprising a unit to keep the belt horizontal at an uppermost position at a top of an arc through which the belt swings. 
     
     
         8 . The sheet feeding device according to  claim 1 , further comprising an insulating sheet disposed on a bottom plate portion of the sheet feeding device,
 wherein at least a portion of the insulating sheet disposed near the surface of the sheet storage stand contacting the belt comprises an insulating material.   
     
     
         9 . The sheet feeding device according to  claim 1 , further comprising a unit to feed each sheet from the stack of multiple sheets using frictional force between the unit and sheets at a position where the sheets are separated from the belt. 
     
     
         10 . The sheet feeding device according to  claim 1 , further comprising a separation unit contacting the belt, wherein the separation unit swings together with the belt. 
     
     
         11 . The sheet feeding device according to  claim 10 , wherein the separation unit comprises a separation pick. 
     
     
         12 . The sheet feeding device according to  claim 10 , wherein the separation unit comprises a friction pad. 
     
     
         13 . The sheet feeding device according to  claim 10 , wherein the separation unit comprises a separation roller. 
     
     
         14 . The sheet feeding device according to  claim 13 , wherein the separation roller is reversely rotatable. 
     
     
         15 . An image forming apparatus comprising a sheet feeding device, the sheet feeding device comprising:
 a belt comprising a dielectric material seamlessly wound about rollers and disposed opposite a top surface of a stack of multiple sheets placed on a sheet storage stand to attract a sheet from the stack of multiple sheets and convey the sheet; and   a charger to form a predetermined-charge pattern on a surface of the belt,   wherein:   a shaft of one of the rollers provided downstream from the other roller in a direction of sheet feed serves as a pivot of the belt about which the belt swings; and   the belt swings around the pivot such that the surface of the belt facing the top surface of the stack of multiple sheets and a surface of the sheet storage stand facing the surface of the belt are substantially parallel to each other.