Sheet feeding device

Abstract

A sheet feeding device includes a feed roller consisting of a rigid roller and an elastic coating covering at least part of the feed roller. A sheet is placed between the pressing member and the feed roller and is pressed tightly by the pressing member. While the feed roller rotates, the sheet is fed by means of the friction between the sheet and the pressing member and between the sheet and the feed roller. The thickness of the elastic coating is preferably much less than the radius of the rigid roller, and is also preferably less than 0.5 millimeter.

What is claimed is:  
     
         1 . A sheet feeding device, comprising: 
 a feed roller comprising a rigid roller and an elastic coating covering at least part of said rigid roller, the thickness of said elastic coating being substantially less than 1 millimeter, and said feed roller rotating to feed a sheet; and    a pressing member, said sheet being placed between said pressing member and said feed roller, and said sheet being pressed tightly by said pressing member.    
     
     
         2 . The sheet feeding device of  claim 1 , wherein the thickness of said elastic coating is substantially less than 0.5 millimeter.  
     
     
         3 . The sheet feeding device of  claim 1 , wherein said elastic coating is a rubber coating.  
     
     
         4 . The sheet feeding device of  claim 3 , wherein the thickness of said rubber coating is substantially less than 1 millimeter.  
     
     
         5 . The sheet feeding device of  claim 4 , wherein the thickness of said rubber coating is substantially less than 0.5 millimeter.  
     
     
         6 . A sheet feeding device built in a printer for feeding a sheet, comprising: 
 a feed roller comprising a rigid roller and an elastic coating covering part of said rigid roller, the thickness of said elastic coating being less than a specific thickness, and said specific thickness being much less than the radius of said rigid roller; and    a pressing member operating in conjunction with said feed roller for feeding said sheet, and said sheet being placed between said pressing member and said rigid roller, and said sheet being pressed tightly by said pressing member.    
     
     
         7 . The sheet feeding device of  claim 6 , wherein said specific thickness is substantially 1 millimeter.  
     
     
         8 . The sheet feeding device of  claim 6 , wherein said specific thickness is substantially 0.5 millimeter.  
     
     
         9 . The sheet feeding device of  claim 6 , wherein the said elastic coating consists of rubber.  
     
     
         10 . A sheet feeding device built in a printer for feeding a sheet, comprising: 
 a feed roller comprising a rigid roller and a rubber coating covering part of said rigid roller, and the thickness of said rubber coating being less than 1 millimeter; and    a pressing member operating in conjunction with said feed roller for feeding said sheet, said sheet being placed between said pressing member and said rigid roller, and said sheet being pressed tightly by said pressing member.    
     
     
         11 . The sheet feeding device of  claim 10 , wherein the thickness of said rubber coating is substantially less than 0.5 millimeter.