Paper feeding apparatus

Abstract

A motor is driven according to a total feeding amount of a recording paper calculated based on the number of prints. When a gear is rotated in a counterclockwise direction, an end of a coil spring is moved upward and a retaining arm is rotated. A tip of a separation plate fixed to the retaining arm is moved to a contact position in which the tip contacts an outer peripheral surface of a paper roll. The separation plate presses the outer peripheral surface with a constant pressing force by a coil spring. When the paper roll is rotated, the separation plate separates a paper end. Thereafter, the gear is rotated in a clockwise direction to move the end of the coil spring downward so that the separation plate moves to a retracting position away from the outer peripheral surface. During printing, the separation plate is in the retracting position.

1 . A paper feeding apparatus for a paper roll formed by winding a continuous recording paper in a roll form, said paper feeding apparatus feeding said recording paper by rotating said paper roll, said paper feeding apparatus comprising: 
 an end separating section able to contact an outer peripheral surface of said paper roll, said end separating section separating a leading end of said recording paper from said outer peripheral surface;    a retaining section for retaining said end separating section, said retaining section moving according to an outer diameter of said paper roll for bringing said end separating section into contact with said outer peripheral surface; and    a biasing section for biasing said end separating section such that said end separating section contacting said outer peripheral surface with an approximately constant pressing force.    
     
     
         2 . A paper feeding apparatus according to  claim 1 , wherein said end separating section is a separation plate whose end has a wedge shape.  
     
     
         3 . A paper feeding apparatus according to  claim 2 , said retaining section including: 
 a retaining arm for retaining said separation plate, said retaining arm being movable between a contact position in which said separation plate comes in contact with said outer peripheral surface at an approximately constant angle and a retracting position in which said separation plate being retracted from said paper roll; and    a support shaft for rotatably supporting said retaining arm.    
     
     
         4 . A paper feeding apparatus according to  claim 3 , wherein said biasing section includes a coil spring wound around said support shaft, said coil spring has a first end attached to said retaining arm and a movable second end, a rotation amount of said retaining arm and a pressing force of said separation plate are adjusted according to a position of said second end.  
     
     
         5 . A paper feeding apparatus according to  claim 4 , said biasing section further including: 
 a spring hook member fixed to said supporting shaft, said second end of said coil spring being engaged with said spring hook member; and    a motor for rotating said supporting shaft.    
     
     
         6 . A paper feeding apparatus according to  claim 5 , further including: 
 an integrator for integrating a total feeding amount of said recording paper; and    a controller for controlling a rotation amount of said motor according to said total feeding amount.    
     
     
         7 . A paper feeding apparatus according to  claim 4 , further including: 
 a stationary spring hook member, said stationary spring hook member having plural engaging slots for adjusting an elastic force of said coil spring, said second end of said coil spring fitting to one of said engaging slots.    
     
     
         8 . A paper feeding apparatus according to  claim 2 , wherein said retaining section is linearly movable between a contact position in which said separation plate contacts said outer peripheral surface at an approximately constant angle and a retracting position in which said separation plate is retracted from said paper roll.  
     
     
         9 . A paper feeding apparatus according to  claim 8 , wherein said biasing section includes a coil spring, said coil spring has a first end attached to said retaining section and a linearly movable second end, a position of said retaining section and a pressing force of said separation plate are adjusted according to a position of said second end.