JPH07130127A - Tape cartridge - Google Patents

Abstract

PURPOSE:To improve rotating accuracy by lessening the load at the time of rotating of a tape guide roller which is freely rotatably inserted and supported with some clearance onto a shaft erected to a roller pedestal on the inside surface side of a cartridge case. CONSTITUTION:The roller pedestal 5 is integrally projected and formed on the inside surface of the cartridge case 1. The flat roller bearing surface 5a of the roller pedestal 5 is formed as a rough surface uniformly formed with fine ruggedness. The rough surface is transferred and formed by the electric discharge machining surface of a metal mold.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape cartridge provided with a tape guide roller, and more particularly to a tape guide roller provided with measures for improving the rotation performance.

[0002]

2. Description of the Related Art For example, in a beta type tape cartridge shown in FIG. 3, a pair of left and right reels 2 and 2 are housed in a cartridge case 1, and a tape 3 wound on one reel 2 is attached to the cartridge case 1. The tape guide rollers 4 are arranged at several points in the course of running the tape, which are taken out to the front side of the reel and wound on the other reel 2. There, as shown in FIG. 1, a roller receiving base 5 is integrally formed on the inner surface of the cartridge case 1 so as to project, and a shaft 6 made of metal or plastic is erected on the roller receiving surface 5a of the roller receiving base 5. The tape guide roller 4 is rotatably inserted through and supported by the shaft 6 with a slight clearance. This type of roller 4 rotates while the tape 3 is in contact with the outer peripheral surface of the roller 4, and the tape running path is changed without damaging the tape 3 or applying extra tension.

[0003]

However, the roller receiving surface 5a of the roller receiving base 5 which receives the axial end surface of the tape guide roller 4 has a fine surface roughness and is formed as a smooth surface. When processing the plastic molding die of the cartridge case 1, the concave portion for molding the roller pedestal is machined, and the roller receiving surface 5a of the roller pedestal 5 plastic-molded in the concave portion is ground by dies. This is because the smooth surface is directly transferred. The roller receiving surface 5a thus formed into a smooth surface makes surface contact with the end surface of the tape guide roller 4. Therefore, the sliding frictional resistance of the tape guide roller 4 is relatively large and a high load is applied when the roller is rotated, so that the smoothness of rotation is deteriorated. In particular, the tape guide roller that is required to have high rotational accuracy or high speed rotation has insufficient accuracy, which causes an increase in dropout of the tape cartridge.

It is an object of the present invention to improve the roughness of the contact surface between the end surface of the tape guide roller and the roller receiving surface in the tape cartridge provided with the tape guide roller that can be received on the roller receiving table, thereby improving the roller surface. This is to reduce the load during rotation and improve the smoothness of rotation.

[0005]

A tape cartridge, which is a premise of the present invention, has a roller holder 5 projectingly formed on the inner surface of a cartridge case 1 and a flat roller holder of the roller holder 5 as shown in the figure. The shaft 6 is erected on the surface 5a,
The tape guide roller 4 is rotatably inserted through the shaft 6, and the axial end surface 4a of the tape guide roller 4 is received on the roller receiving surface 5a. In addition, the surface of either the roller receiving surface 5a or the axial end surface 4a of the tape guide roller 4 is formed as a rough surface on which fine irregularities are uniformly formed. The minimum height roughness of the unevenness is 3 to 5 μm.

[0006]

The fine irregularities serve to reduce the frictional resistance at the contact surface between the axial end surface 4a of the tape guide roller 4 and the roller pedestal 5.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The basic structure of the target tape cartridge is the same as that of the conventional example shown in FIG. In FIG. 1, a roller holder 5 is integrally formed on the inner surface of a plastic cartridge case 1 along the tape running path, and a metal shaft 6 is formed at the center of a flat roller receiving surface 5a of the roller holder 5. Is set up. The shaft 6 may be made of plastic which is integrally erected from the roller pedestal 5. The tape guide roller 4 is formed of a plastic in a cylindrical shape, and is rotatably inserted and supported by the shaft 6 with a slight clearance.

In FIG. 2, the roller receiving surface 5 of the roller receiving table 5 is shown.
The surface roughness of a is formed in a matte-finished rough surface on which fine irregularities are uniformly formed. The minimum height roughness of the rough surface is 3 μ to 5 μ. This is because if it is less than that, the surface becomes close to a smooth surface, and the effect of reducing the frictional resistance of the tape guide roller 4 cannot be sufficiently achieved. The surface roughness of the roller receiving surface 5a of the roller pedestal 5 is such that the concave portion for molding the roller pedestal is ground by electric discharge machining in the machining of the molding die of the cartridge case 1 and the electric discharge machining surface of the inner bottom of the concave portion Since it can be ground into a satin-like shape that uniformly forms fine irregularities, the roughness of the electric discharge machined surface can be directly transferred to form irregularities with a minimum height roughness of 3 to 5 μm. be able to.

The surface of the roller receiving surface 5a of the roller receiving base 5 is formed to be a smooth surface as in the conventional case, and the surface roughness of the axial end surface 4a of the tape guide roller 4 is made to be a rough surface in which fine irregularities are uniformly formed. Good. The target tape cartridge is not limited to the illustrated example, but may be similarly applied to, for example, a VHS tape cartridge.

[0010]

According to the present invention, the surface of either the roller receiving surface 5a or the axial end surface 4a of the tape guide roller 4 is formed as a rough surface on which fine irregularities are uniformly formed.
Therefore, since the frictional resistance at the contact surface between the tape guide roller 4 and the roller pedestal 5 can be reduced, a roller guide with a light load can be realized, and the roller 4 can be provided with smooth rotatability. It is also possible to improve the followability of the tape to the roller 4 and reduce the increase in dropout. In addition, tape slipping can be prevented, which is also effective in preventing noise and dust during running of the tape.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a main part.

FIG. 2 is a sectional view taken along line AA in FIG.

FIG. 3 is a plan view of the inside of the tape cartridge.

[Explanation of symbols]

 1 Cartridge case 4 Tape guide roller 5 Roller pedestal 6 Axis

Claims (2)

[Claims] 1. A roller pedestal 5 is formed so as to project from the inner surface of a cartridge case 1, and a shaft 6 is erected on a flat roller receiving surface 5a of the roller pedestal 5, and a tape guide is provided on the shaft 6. In a tape cartridge in which the roller 4 is rotatably inserted and the axial end surface 4a of the tape guide roller 4 is received on the roller receiving surface 5a, either the roller receiving surface 5a or the axial end surface 4a of the tape guide roller 4 is provided. A tape cartridge characterized in that one surface is formed as a rough surface on which fine irregularities are uniformly formed. 2. The tape cartridge according to claim 1, wherein the unevenness has a minimum height roughness of 3 to 5 μm.