Apparatus for feeding printing paper

Abstract

Disclosed is an apparatus for feeding sheets of printing paper individually, which includes: a paper tray; a rubber pad installed in the proximity to the front end of a paper stack on the paper tray; a separating/transferring roller having a nozzle part on its outer periphery, for separately feeding a paper sheet using absorption force, wherein the separating/transferring roller is so spaced that its upper surface does not have an effect on the back of the lowermost paper sheet on the paper tray and the separating/transferring roller has such diameter that its lower surface faces the upper window of the scanning unit. With such construction, reliability of a paper separation and pickup can be increased with use of only one single separating/transferring roller. Manufacturing costs can be reduced, noise due to gear connection can be reduced, and installation space can also be reduced. Thus, a scanner having a more compact design can be manufactured.

1 . An apparatus for separating and feeding printing paper sheets individually from a paper tray on which the printing paper sheets are stacked, the apparatus comprising: 
 one single separating/transferring roller for sucking a paper sheet from the paper stack on the paper tray and delivering the paper sheet to a scanning unit.    
     
     
         2 . The apparatus according to  claim 1 , wherein the separating/transferring roller is so spaced that its upper surface does not have an effect on the back of the lowermost paper sheet on the paper tray and the separating/transferring roller has such a diameter that its lower surface faces an upper window of the scanning unit.  
     
     
         3 . The apparatus according to  claim 1 , further comprising a rubber pad installed in the proximity to a front end of the paper stack on the paper tray, for facilitating the separation of the paper sheet.  
     
     
         4 . The apparatus according to  claim 1 , wherein the separating/transferring roller has at least one nozzle part formed on an outer periphery for sucking the paper sheet, and a vacuum pump for providing absorption force to the nozzle part.  
     
     
         5 . The apparatus according to  claim 1 , further comprising a paper guiding part formed in a shape that corresponds to a shape of an outer periphery of the separating/transferring roller, for guiding a paper sheet delivered by the separating/transferring roller.  
     
     
         6 . The apparatus according to  claim 5 , further comprising: a paper perception sensor unit for sensing whether a paper is present on the paper tray; a scanning sensor unit installed in the paper guiding part, for sensing a delivered paper sheet; and a controlling unit for controlling operating of the vacuum pump.  
     
     
         7 . The apparatus according to  claim 4 , wherein a plurality of the nozzle parts is formed on a straight line along an axial direction of the separating/transferring roller.  
     
     
         8 . The apparatus according to  claim 4 , wherein a plurality of the nozzle parts is formed alternately in a cylindrical direction on two parallel straight lines along an axial direction of the separating/transferring roller.  
     
     
         9 . The apparatus according to  claim 1 , wherein the separating/transferring roller has a frictional part on its outer peripheral surface so that increased frictional force is exerted on the delivered paper sheet.  
     
     
         10 . The apparatus according to  claim 4 , wherein the separating/transferring roller has a frictional part on its outer peripheral surface so that increased frictional force is exerted on the delivered paper sheet.  
     
     
         11 . The apparatus according to  claim 4 , wherein the separating/transferring roller has a frictional part on its outer peripheral surface except vicinity of the nozzle part so that increased frictional force is exerted on the delivered paper sheet.  
     
     
         12 . The apparatus according to  claim 7 , wherein the separating/transferring roller has a frictional part on its outer peripheral surface except vicinity of the nozzle part so that increased frictional force is exerted on the delivered paper sheet.  
     
     
         13 . The apparatus according to  claim 6 , wherein the controlling unit operates the vacuum pump if a scanning command of a user is input after the paper perception sensor unit is turned “on.” 
     
     
         14 . The apparatus according to  claim 6 , wherein the controlling unit stops operation of the vacuum pump if the scanning sensor unit is turned “on” by a front end of the delivered paper sheet stuck on the outer periphery of the separating/transferring roller, and operates again the vacuum pump if a rear end of the delivered paper sheet passes by the scanning sensor unit.  
     
     
         15 . The apparatus according to  claim 13 , wherein the controlling unit stops operation of the vacuum pump if the scanning sensor unit is turned “on” by a front end of the delivered paper sheet stuck on the outer periphery of the separating/transferring roller, and operates again the vacuum pump if a rear end of the delivered paper sheet passes by the scanning sensor unit.  
     
     
         16 . The apparatus according to  claim 6 , wherein the controlling unit stops operation of the vacuum pump if both the paper perception sensor unit and the scanning sensor unit are all turned “off.” 
     
     
         17 . The apparatus according to  claim 14 , wherein the controlling unit stops operation of the vacuum pump if both the paper perception sensor unit and the scanning sensor unit are all turned “off.”