JP2002352550A - Tape cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tape cassette, in which the tape can be stably run even though the tilt of a shaft for pivotally supporting a guide roller to be rotatable is large. SOLUTION: The guide roller 44 pivotally and rotatably supported in a case 11 to guide the supplying and winding back of the magnetic tape T wound round the reel is arranged in the magnetic tape cassette 10. The allowable moving distance d to the axial center direction of the guide roller 44 is suppressed within the range of 0.05 mm-2.0 mm which his shortened as compared with that of the conventional one. Thus, the movement amount is suppressed even though the magnetic tape T is moved to the axial center direction in the course of the running of the magnetic tape T.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape cassette provided with a guide roller for guiding the feeding and rewinding of a tape.

[0002]

2. Description of the Related Art In general, in audio equipment and video equipment, a magnetic tape cassette for recording and reproducing data while holding a magnetic tape wound around a pair of reels in a cassette case so as to be able to run is often used.

For example, as shown in FIG. 4, a magnetic tape cassette 70 used for business use in a broadcasting station is provided with a case 7.
1, a lower flange 75, a hub 76 integrally fixed to the upper side of the lower flange 75, and an upper flange 78 attached to the upper side of the hub 76. A pair of configured reels 79 is rotatably supported on a shaft, and a magnetic tape T is wound around the pair of reels 79.

A guide roller 84 for guiding the magnetic tape T at the time of feeding or rewinding is provided near the opening on the front side of the magnetic tape cassette 70. The guide roller 84 is rotatably supported by a shaft 80, and the shaft 80 is generally supported from below by a lower half 74.

However, when the magnetic tape T is used by being loaded on the deck, there is a problem that the magnetic tape T fluctuates in the width direction and the tape running becomes unstable. And
The cause of this tape variation was unknown.

The movable distance in the direction parallel to the axis of the guide roller 84 is set between the lower end of the shaft fitting portion 82U formed on the inner wall surface of the upper half 72 and the guide when no tension is applied to the magnetic tape T. It is determined by a clearance L formed between the roller 84 and the roller 84. Conventionally, the value of the clearance L is formed by stacking dimensional errors in manufacturing the case 71 and the guide roller 84, and is generally in the range of 0.3 mm to 0.5 mm. Conventionally, this clearance L has not been particularly adjusted.
It is unclear how this affects the meandering of the magnetic tape T.

Conventionally, when erecting the shaft 80, it is necessary to erect the shaft 80 perpendicular to the running direction of the magnetic tape T. If it is not perpendicular, when it receives a moving force from the running magnetic tape T in a direction parallel to the axis, the guide roller 84
This is to avoid this, since it is easy to move.

[0008] The running direction of the magnetic tape T is generally parallel to the case surface, and the inner wall surface 74U of the lower half 74 constituting the case 71 in order to erect the shaft 80 perpendicular to the running direction of the magnetic tape T. It stands upright with respect to. Then, the allowable inclination angle θ in the shaft axis direction Z2 with respect to the direction Z1 orthogonal to the inner wall surface 74U of the lower half 74
Must be kept within 1 °, which has hindered the improvement of the production efficiency of the magnetic tape cassette 70.

[0009] These problems are not limited to magnetic tape cassettes, but generally occur in tape cassettes.

[0010]

SUMMARY OF THE INVENTION In consideration of the above fact, the present invention provides a tape cassette which can stably run a tape even when a shaft for rotatably supporting a guide roller has a large inclination. The task is to provide.

[0011]

According to a first aspect of the present invention, there is provided a tape cassette provided with a guide roller rotatably supported by a case and guiding feeding and rewinding of a wound tape. An allowable moving distance in a direction parallel to an axis of the guide roller is set in a range of 0.05 mm to 0.2 mm.

A change in the position of the tape that occurs during traveling is caused by a guide roller that guides the tape receiving a moving force from the tape.
One of the causes is that the tape moves together with the tape along a direction parallel to the axis.

According to the first aspect of the present invention, since the allowable movement distance in the direction parallel to the axis of the guide roller is limited, the amount of movement of the tape during use of the tape cassette, that is, during tape running, can be suppressed. .

A shaft for rotatably supporting the guide roller is provided upright in a case forming an outer frame of the tape cassette, and a hole for inserting the shaft is formed in the guide roller along the axis. Often. In this case, since the above-mentioned allowable movement distance is determined by the value of the clearance between the inner wall of the case and the guide roller, the above-mentioned allowable movement distance is suppressed by actively adjusting and reducing the value of the clearance. be able to.

[0015] The value of the clearance is preferably 0.2 mm or less. However, since the guide roller needs to be rotatable, the lower limit of the clearance is
It is preferably about 0.05 mm.

Further, by suppressing the allowable movement distance in the direction parallel to the axis of the guide roller, the axial direction of the shaft rotatably supporting the guide roller can be changed as follows.
Even if it is not so perpendicular to the running direction of the unwound magnetic tape, the amount of movement of the guide roller in the axial direction during the running of the tape can be suppressed. Therefore, the allowable inclination angle of the shaft becomes large, so that the production efficiency of the tape cassette can be remarkably improved.

[0017]

Embodiments of the present invention will be described below with reference to embodiments.

As shown in FIG. 1, a magnetic tape cassette (Betacam L cassette) 1 used for business in a broadcasting station
0 is the upper half 12 and the lower half 1 that constitute the case 11
4 is provided.

Inside the case 11 formed by the upper half 12 and the lower half 14, a lower flange 24, a hub 26 integrally fixed on the upper side of the lower flange 24, and a hub 26 mounted on the upper side of the hub 26. And a pair of reels 20 constituted by an upper flange 28 are rotatably supported by a shaft.
A magnetic tape T is wound around the pair of reels 20. In addition, engaging teeth (not shown) for transmitting a rotating power are formed on the outer peripheral portion of the lower flange 24. The upper half 12 is provided with a window 13 made of a transparent plate.

The upper half 12 is provided with a pair of reel urging leaf springs 36 formed by bending a band-shaped metal. The leaf springs 36 for urging the reels include arm portions 38A,
8B and the base end 40, and the base end 40 is
Is fixed to the inner wall surface. Thereby, the arm 38
A and 38B urge the corresponding reels 20A and 20B toward the lower half 14, respectively.

The opening 1 on the front side of the magnetic tape cassette 10
In the vicinity of 6, a pair of guide rollers 44 for guiding the magnetic tape T when the magnetic tape T is fed and wound is arranged. The magnetic tape cassette 10 has a magnetic tape T
The magnetic tape T is pressed toward the guide roller 44 with an appropriate urging force by the pad 48.

A shaft 50 is provided to project from the inner wall surface 14U of the lower half 14, and the shaft 50 is provided with a through hole 44 formed along the center axis of the guide roller 44.
H, and the guide roller 44 is
Is rotatably supported on the axis. This shaft 5
0 is fixed in the vertical direction by the upper half 12 and the lower half 14.

The guide roller 44 is made of a material having lubricity and relatively high mechanical strength, for example, a resin such as POM. In order to ensure the running stability of the magnetic tape T and efficiently guide the magnetic tape T,
The outer shape of the guide roller 44 may be formed in a drum shape.

As shown in FIGS. 2 and 3, the guide roller 4
4, the upper end of the guide roller 44 and the lower end of the short cylindrical shaft fitting portion 52U formed on the inner wall surface (lower surface) 12L of the upper half 12 in a state where the tension F of the magnetic tape T is not applied. , The clearance d formed between them is smaller than in the prior art. In order to obtain sufficient rotation performance of the guide roller 44, the value of d is 0.05 mm to 0.5 mm.
It is preferably within a range of 2 mm.

Since the clearance d is smaller than the conventional clearance L (see FIG. 4), the allowable moving distance d in the direction parallel to the axis of the guide roller 44 (vertical direction) is equal to the conventional allowable moving distance. L (see FIG. 4). Therefore, the vertical position fluctuation amount of the magnetic tape T during running can be suppressed within a smaller range (d or less) than in the related art.

This means that the shaft 50 is connected to the lower half 14.
This is extremely effective in standing upright on the inner wall surface (upper surface) 14U.

The shaft 50 is connected to the inner wall surface 14 of the lower half 14.
When the shaft 50 is erected on the shaft fitting portion 52L formed on the U side, the shaft 50 is connected to the inner wall surface side (upper surface side) of the lower half 14.
It is erected by driving in from. In the present embodiment, the amount of vertical position change of the guide roller 44 rotated along with the magnetic tape T is suppressed within a range of d smaller than that of the related art, so that the shaft axis with respect to the direction Z1 Even when the allowable inclination angle θ in the direction Z2 is larger than 1 °, the running stability of the magnetic tape T can be sufficiently ensured.

Thus, when the magnetic tape cassette 10 is manufactured, the number of standing shafts 50 per unit time can be remarkably improved, so that the manufacturing efficiency can be remarkably improved.

[0029]

According to the present invention having the above-described structure, a tape cassette which can stably run the tape even when the inclination of the shaft rotatably supporting the guide roller is large is realized.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a magnetic tape cassette according to a first embodiment.

FIG. 2 is a side sectional view of the magnetic tape cassette of the first embodiment (corresponding to arrow 2-2 in FIG. 1).

FIG. 3 is an enlarged view of FIG. 2;

FIG. 4 is an enlarged side sectional view showing a configuration of a conventional magnetic tape cassette.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Magnetic tape cassette 11 Case 44 Guide roller 70 Magnetic tape cassette 71 Case 84 Guide roller

Claims (1)

[Claims] 1. A tape cassette provided with a guide roller rotatably supported by a case and guiding feeding and rewinding of a wound tape, wherein a permissible moving distance in a direction parallel to an axis of the guide roller is determined. 0.
A tape cassette characterized by being in the range of 05 mm to 0.2 mm.