Sheet separating device for an image input/output apparatus

Abstract

A sheet separating device for an image input/output apparatus includes a ADF roller, a multi-layer pad and a spring. The spring forces elastically the multi-layer pad to contact the surface of the ADF roller. The multi-layer pad is composed of a first pad layer and a second pad layer superposed on the first pad layer in a stepped condition, and the second pad layer contacts the ADF roller in a pressed-over way. In separating sheets, the first pad layer and the second pad layer respectively separate sheets for two stages of action so that the probability of single sheet picking may be increased greatly. The first stage and the second stage of sheet separation are sequent and successive, not affecting the speed of sheet movement or the time needed for scanning or printing an image.

1 . A sheet-separating device for an image input/output apparatus, said sheet-separating device disposed in a sheet feeder for feeding papers one sheet by one sheet, said sheet-separating device comprising; 
 a ADF roller combined rotatably in said sheet feeder;    a multi-layer pad fixed in a body of said sheet feeder and facing to said ADF roller, said multi-layer pad composed of at least a first pad layer and a second pad layer superposed on said first pad layer in a stepped condition;    an elasticity element for pushing elastically said multi-layer pad to bias against said ADF roller; and,    said second pad layer of said multi-layer pad contacting said ADF roller in a pressed-over way.    
   
   
       2 . The sheet separating device as claimed in  claim 1 , wherein said first pad layer and said second pad layer are made of different materials.  
   
   
       3 . The sheet separating device as claimed in  claim 1 , wherein said first pad layer and said second pad layer are made of the same material.  
   
   
       4 . The sheet separating device as claimed in  claim 1 , wherein a mylar is further provided to be attached on said second pad layer to contact said ADF roller.  
   
   
       5 . The sheet separating device as claimed in  claim 1 , wherein said first pad layer and said second pad layer are formed as integral as one unit in a stepped condition.  
   
   
       6 . The sheet separating device as claimed in  claim 1 , wherein said second pas layer has a saw shape formed in its front end contacting said ADF roller.  
   
   
       7 . The sheet separating device as claimed in  claim 1 , wherein said spring is posited between the multi-layer pad and a body of said auto sheet feeder.