Tape cartridge

Abstract

A tape cartridge has a reel having an external peripheral surface and a tape wound around the external peripheral surface of the reel. The peripheral surface has a shallow recess defined therein and extending in a peripheral direction of the reel. The recess is extended in a direction opposite a tape winding direction from a first point to a second point away from the first point. The recess is defined by an end wall extending inwardly from the first point to a third point away from the first point and a height substantially the same as a thickness of the tape. The recess also has a bottom wall extending peripherally from the third point to the second point and having a depth decreasing in proportion to a distance from the third point toward the second point. The portion of the tape is positioned in the recess so that the end wall abuts or opposes the end portion of the tape.

1 . A tape cartridge, comprising:
 a reel having an external peripheral surface; and   a tape wound around the external peripheral surface of the reel;   the peripheral surface having a shallow recess defined therein and extending in a peripheral direction of the reel, the recess being extended in a direction opposite a tape winding direction from a first point to a second point away from the first point, the recess being defined by an end wall extending inwardly from the first point to a third point away from the first point and a height substantially the same as a thickness of the tape and a bottom wall extending peripherally from the third point to the second point and having a depth decreasing in proportion to a distance from the third point toward the second point;   one end portion of the tape being positioned in the recess so that the end wall abuts or opposes the end portion of the tape.   
   
   
       2 . The tape cartridge of  claim 1 , wherein the bottom wall has a radius of curvature substantially the same as that of the peripheral surface. 
   
   
       3 . The tape cartridge of  claim 1 , wherein the bottom surface has a straight wall portion formed adjacent the third point and a curved wall portion adjacent the second point and having a radius of curvature substantially the same as that of the peripheral surface. 
   
   
       4 . The tape cartridge of  claim 1 , wherein a height of the end wall has a size tolerance of about ±0.5% of the tape thickness T.