Paper conveyance apparatus for an image forming apparatus and a method thereof

Abstract

A paper conveyance apparatus and method for an image forming apparatus are disclosed. The paper conveyance apparatus and method provide an improved structure in which when the distance between the conveyance roller shaft and the reversible roller shaft is shortened due to the abrasion of the reversible roller, the center of a gear train which transmits a driving force to the reversible roller is swung to move as much as the shortened distance so that the reversible roller can be continuously in contact with the conveyance roller. The paper conveyance apparatus and method comprise a conveyance roller for conveying a paper sheet to an image forming section, a reversible roller for contacting the conveyance roller, a driving motor having a driving gear for supplying a driving force to the reversible roller, and an idle gear for transmitting a driving force from the driving motor to the reversible roller. The center of rotation of the idle gear is movable according to the degree of abrasion of the reversible roller in order to transmit a driving force from the driving motor to the reversible roller.

1 . A paper conveyance apparatus for an image forming apparatus, comprising: 
 a conveyance roller for conveying a paper sheet to an image forming section;    a reversible roller for contacting the conveyance roller;    a driving motor having a driving gear for supplying a driving force to the reversible roller; and    an idle gear for transmitting a driving force from the driving motor to the reversible roller,    wherein the center of rotation of the idle gear is movable according to the degree of abrasion of the reversible roller in order to transmit a driving force from the driving motor to the reversible roller.    
   
   
       2 . The paper conveyance apparatus according to  claim 2 , wherein the idle gear is movable along a track which is a part of the circumference of a virtual circle having a radius corresponding to a distance between the center of the driving gear and the center of the idle gear.  
   
   
       3 . The paper conveyance apparatus according to  claim 2 , wherein a central shaft of the idle gear is movable along a swing slot formed on one sidewall of the image forming apparatus to correspond to the swing track of the idle gear.  
   
   
       4 . The paper conveyance apparatus according to  claim 3 , wherein the swing slot has an inner periphery with a curvature corresponding to the swing track of the idle gear.  
   
   
       5 . The paper conveyance apparatus according to  claim 3 , wherein the swing slot is formed in a direction of a tangent to a virtual circle having a radius corresponding to the distance between the center of the driving gear and the center of the idle gear.  
   
   
       6 . The paper conveyance apparatus according to  claim 5 , wherein the swing slot comprises an elastic member for elastically supporting the central shaft of the idle gear.  
   
   
       7 . A method of feeding paper in an image forming apparatus, comprising: 
 conveying a paper sheet to an image forming section via a conveyance roller;    contacting the conveyance roller via a reversible roller;    supplying a driving force to the reversible roller via a driving motor having a driving gear; and    transmitting a driving force from the driving motor to the reversible roller via an idle gear,    wherein the center of rotation of the idle gear is movable according to the degree of abrasion of the reversible roller in order to transmit a driving force from the driving motor to the reversible roller.    
   
   
       8 . The method according to  claim 7 , wherein the idle gear is movable along a track which is a part of the circumference of a virtual circle having a radius corresponding to a distance between the center of the driving gear and the center of the idle gear.  
   
   
       9 . The method according to  claim 8 , further comprising: 
 providing a central shaft of the idle gear which is movable along a swing slot formed on one sidewall of the image forming apparatus to correspond to the swing track of the idle gear.    
   
   
       10 . The method according to  claim 9 , wherein the swing slot has an inner periphery with a curvature corresponding to the swing track of the idle gear.  
   
   
       11 . The method according to  claim 9 , wherein the swing slot is formed in a direction of a tangent to a virtual circle having a radius corresponding to the distance between the center of the driving gear and the center of the idle gear.  
   
   
       12 . The method according to  claim 11 , wherein the swing slot comprises an elastic member for elastically supporting the central shaft of the idle gear.