Recording medium feeding device

Abstract

In the device for feeding the recording medium by rotating the roll body by using one feed roller, an angle is formed between the direction of the line segment connecting the centers of rotation of the roll body and the feed roller and the movement direction in which the roll body or the feed roller moves as the diameter of the roll body decreases. For example, in the case where the roll body is moved, the contact point between the roll body and the feed roller shifts to the downstream side of the roll body from the line segment connecting the centers of rotation of the roll body and the feed roller. Therefore, when the roll body is rewound by the feed roller, the contact pressure between the roll body and the feed roller can be increased, and thereby the winding slack of the roll body can be prevented.

1 . A recording medium feeding device in which one of right and left support shafts for holding a roll body formed by winding a recording medium in a roll form and one feed roller for rotating the roll body in such a manner as to be in contact with a peripheral surface of the roll body is fixed, and the other thereof is moved as the diameter of the roll body decreases, wherein 
 an angle is formed between the direction of a line segment connecting the centers of rotation of the roll body and the feed roller and the movement direction in which the roll body or the feed roller moves as the diameter of the roll body decreases, so that when the recording medium is rewound on the roll body by the feed roller, a contact pressure at a contact point between the roll body and the feed roller increases.    
     
     
         2 . The recording medium feeding device according to  claim 1 , wherein 
 the recording medium feeding device has a pair of right and left guide members for movably guiding the support shafts of the roll body in the radial direction of the roll body and an urging device for urging the roll body to the movement direction of the roll body guided by the guide members, so that the support shaft of the roll body is moved by the guide members and the urging device as the diameter of the roll body decreases, and    the feed roller is arranged so that the contact point at which the feed roller is in contact with the roll body shifts from a tangential position at which the movement direction of the roll body moved by being guided by the guide members is a normal to the downstream side of the roll body.    
     
     
         3 . The recording medium feeding device according to  claim 2 , wherein the feed roller is arranged at a position at which taking the maximum radius of the roll body as R 1 , the minimum radius thereof as R 2 , and the radius of the feed roller as Rf, an angle θ between a line segment connecting the centers of rotation of the roll body with the maximum radius and the feed roller and a normal corresponding to the movement direction of the roll body is represented by the following inequality.  
         0<θ<sin −1 {( R   2 + Rf )/( R   1 + Rf )} 
     
     
         4 . The recording medium feeding device according to  claim 1 , wherein the feed roller sends out the recording medium wound on the roll body at the time of normal rotation and rewinds the recording medium on the roll body sent out from the roll body at the time of reverse rotation, and some of a force acting on the roll body from the feed roller at the time of reverse rotation acts in the direction such that the contact pressure between the roll body and the feed roller is increased.  
     
     
         5 . The recording medium feeding device according to  claim 2 , wherein the feed roller sends out the recording medium wound on the roll body at the time of normal rotation and rewinds the recording medium on the roll body sent out from the roll body at the time of reverse rotation, and some of a force acting on the roll body from the feed roller at the time of reverse rotation acts in the direction such that the contact pressure between the roll body and the feed roller is increased.  
     
     
         6 . The recording medium feeding device according to  claim 3 , wherein the feed roller sends out the recording medium wound on the roll body at the time of normal rotation and rewinds the recording medium on the roll body sent out from the roll body at the time of reverse rotation, and some of a force acting on the roll body from the feed roller at the time of reverse rotation acts in the direction such that the contact pressure between the roll body and the feed roller is increased.  
     
     
         7 . The recording medium feeding device according to  claim 1 , wherein the recording medium is a recording paper in which a coloring layer, which is colored by heat and is fixed by light with a predetermined wavelength, is formed on the surface thereof.  
     
     
         8 . The recording medium feeding device according to  claim 2 , wherein the recording medium is a recording paper in which a coloring layer, which is colored by heat and is fixed by light with a predetermined wavelength, is formed on the surface thereof.  
     
     
         9 . The recording medium feeding device according to  claim 3 , wherein the recording medium is a recording paper in which a coloring layer, which is colored by heat and is fixed by light with a predetermined wavelength, is formed on the surface thereof.  
     
     
         10 . The recording medium feeding device according to  claim 4 , wherein the recording medium is a recording paper in which a coloring layer, which is colored by heat and is fixed by light with a predetermined wavelength, is formed on the surface thereof.  
     
     
         11 . The recording medium feeding device according to  claim 5 , wherein the recording medium is a recording paper in which a coloring layer, which is colored by heat and is fixed by light with a predetermined wavelength, is formed on the surface thereof.  
     
     
         12 . The recording medium feeding device according to  claim 6 , wherein the recording medium is a recording paper in which a coloring layer, which is colored by heat and is fixed by light with a predetermined wavelength, is formed on the surface thereof.