Sheet feeding apparatus and paper separation device thereof

Abstract

A sheet feeding apparatus includes an input tray, a paper picking device, and a paper separation device. The input tray is for placing a plurality of papers. The paper picking device is for performing a paper picking operation on the papers. The paper separation device, including a paper separation surface contacting with the papers placed on the paper tray, is for applying a paper separation force on each of the papers as fed in. When the paper picking device performs the paper picking operation on each of the papers, the paper separation forces applied on the papers are decreased as their paper separation paths are increased.

1 . A paper separation device, used in a sheet feeding apparatus, the sheet feeding apparatus comprising an input tray for placing a plurality of papers, the paper separation device comprising: 
 a paper separation surface, contacting with the papers placed on the input tray, for applying a paper separation force on each of the papers as fed in;    wherein the paper separation forces applied on the fed-in papers are decreased as their paper separation paths are increased.    
   
   
       2 . The paper separation device according to  claim 1 , wherein the paper separation surface comprises a plurality of protrusions arranged along a paper feeding direction for providing the paper separation force.  
   
   
       3 . The paper separation device according to  claim 2 , wherein the protrusions of a regular or an irregular shape have the same or different height.  
   
   
       4 . The paper separation device according to  claim 2 , wherein the protrusions are a plurality of saw strips.  
   
   
       5 . The paper separation device according to  claim 4 , wherein the size of saw gaps between the tops of two adjacent saws is decreased along the paper feeding direction.  
   
   
       6 . The paper separation device according to  claim 5 , wherein each of the saw strip has a first surface facing to the paper feeding direction and a second surface facing against the paper feeding direction, the first surfaces are arranged in parallel, and the second surfaces have decreased inclined angles against a vertical line of the paper separation surface along the paper feeding direction.  
   
   
       7 . The paper separation device according to  claim 4 , wherein the saw strips have gap depth increased along the paper feeding direction.  
   
   
       8 . The paper separation device according to  claim 7 , wherein each of the saw strips has a third surfaces facing to the paper feeding direction and a forth surface facing against the paper feeding direction, the third surfaces are arranged in parallel, and the depth of gaps between the bottoms and the tops of the forth surfaces is decreased along the paper feeding direction.  
   
   
       9 . The paper separation device according to  claim 2 , wherein the protrusions are a plurality of circular protrusions.  
   
   
       10 . The paper separation device according to  claim 9 , wherein the size of gaps between two adjacent circular protrusions is decreased along the paper feeding direction.  
   
   
       11 . The paper separation device according to  claim 9 , wherein the depth of gaps between two adjacent circular protrusions are increased along the paper feeding direction.  
   
   
       12 . A sheet feeding apparatus, comprising: 
 an input tray, for placing a plurality of papers;    a paper picking device, for performing a paper picking operation on the papers; and    a paper separation device, comprising a paper separation surface contacting with the papers placed on the paper tray, for applying a paper separation force on each of the papers as fed in;    wherein when the paper picking device performs the paper picking operation on each of the papers, the paper separation forces applied on the papers are decreased as their paper separation paths are increased.    
   
   
       13 . The sheet feeding apparatus according to  claim 12 , wherein the paper separation surface comprises a plurality of protrusions arranged along a paper feeding direction for providing the paper separation force.  
   
   
       14 . The sheet feeding apparatus according to  claim 13 , wherein the protrusions of a regular or an irregular shape have the same or different height.  
   
   
       15 . The sheet feeding apparatus according to  claim 13 , wherein the protrusions are a plurality of saw strips.  
   
   
       16 . The sheet feeding apparatus according to  claim 15 , wherein the size of saw gaps between two adjacent saw strips is decreased along the paper feeding direction.  
   
   
       17 . The sheet feeding apparatus according to  claim 16 , wherein each of the saw strips has a first surface facing to the paper feeding direction and a second surface facing against the paper feeding direction, the first surfaces are arranged in parallel, and the second surfaces have decreased inclined angles against a vertical line of the paper separation surface along the paper feeding direction.  
   
   
       18 . The sheet feeding apparatus according to  claim 15 , wherein the depth of gaps between two adjacent saws is increased along the paper feeding direction.  
   
   
       19 . The sheet feeding apparatus according to  claim 18 , wherein each of the saw strips has a third surface facing to the paper feeding direction and a forth surface facing against the paper feeding direction, the third surfaces are arranged in parallel, and the depth of gaps between the bottoms and the tops of the forth surfaces is decreased along the paper feeding direction.  
   
   
       20 . The sheet feeding apparatus according to  claim 13 , wherein the protrusions are a plurality of circular protrusions.  
   
   
       21 . The sheet feeding apparatus according to  claim 20 , wherein the size of gaps between two adjacent circular protrusions is decreased along the paper feeding direction.  
   
   
       22 . The sheet feeding apparatus according to  claim 21 , wherein the depth of gaps between two adjacent circular protrusions is increased along the paper feeding direction.