JPH10255438A - Magnetic tape cassette - Google Patents

Abstract

(57) [Problem] To provide a magnetic tape cassette in which a tape is not deformed even when stored in a cassette alone. SOLUTION: A tape guide 6 includes a slide member 6a having a curved surface, the slide member 6a includes a bearing portion 6b provided at a central portion thereof, the bearing portion 6b partially includes a bearing hole 6c, and is provided on a shell of the cassette. A magnetic tape cassette having a configuration in which a bearing hole 6c of a bearing portion 6b is inserted into an upright shaft, and a tape guide 6 can swing around the bearing portion 6b. [Effect] The tension applied to the tape suspended from the tape guide portion is made uniform, and deformation of the tape can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic tape cassette, and more particularly to a magnetic tape cassette having an improved tape guide for guiding a magnetic tape in the magnetic tape cassette.

[0002]

2. Description of the Related Art A general structure of a video tape cassette for recording / reproducing, particularly of a magnetic tape cassette, is shown in FIG.
(A) and (b), which are reels 1a and 1b around which a magnetic tape (hereinafter referred to as "tape") is wound, a tape guide for determining a tape pull-out position, and rotation of the reel to prevent tape bulging. And a reel lock member for locking the tape and applying a certain tension, a lid 2 for protecting the tape, a reel spring for stabilizing the rotation of the reels 1a and 1b, and shells 3a and 3b.

More specifically, FIG. 10 is an exploded view of a DV (digital video) cassette with an IC module.
The reel lock member 4 of this cassette comprises four points of a reel lock slider 4a, reel locks 4b1 and 4b2, and a reel lock spring 4c. A slider spring 5 is mounted on the reel lock slider 4 and further mounted on the upper shell 3a and the lower shell 3b. Fixed, allowing operation.

[0004] The lid 2 is composed of three points: a top lid 2a, a back lid 2b, and a front lid 2c.
Further, the tape guide 6 is formed integrally with the lower shell 3b. In addition to the reel lock spring 4c, the slider spring 5, the screw 7, the IC module 8, and the tape 9, engineering plastics such as ABS and POM are used.

When the cassette enters the VTR, the lid 2 opens and the reel lock member 4 is released, and then the reel 1a,
1b is lifted by the reel base 1c, and the reels 1a, 1b
Is rotated so that the tape 9 does not contact the shells 3a and 3b.
(See FIG. 11 (a).) On the other hand, at the time of ejection, the tape 9 pulled out is rewound, and after the tape 9 is suspended by the tape guide 6, the reel base 1c is lowered. After this, the reels 1a and 1b are lowered and come into contact with the lower shell 3b, then the reel lock member 4 is returned to lock the reels 1a and 1b, and the lid 2 is closed and taken out.

Therefore, as shown in FIG. 11B, the height of the tape 9 wound around the reels 1a and 1b is lower than the height of the tape wound around the tape guide 6, and the tape upper edge 9a Is pulled, the tape tension is high, and the lower edge side 9b is low, resulting in uneven tension in the width direction. If the tape 9 is stored in a high-temperature and high-humidity environment for a long time in a state where the tension in the width direction of the tape 9 is not uniform, the tape 9 is easily affected by the expansion and contraction of the tape 9 and easily bends. This makes it difficult to faithfully reproduce the recorded signal.

This problem occurs particularly when the recorded tape 9 is stored without being rewound. In addition, a thin tape having a low strength that can be used for a long time is easily deformed, and furthermore, in digital recording, as a result, there is a problem that images and sounds are lost. As a countermeasure against this problem, two countermeasures on the VTR side and the cassette side have been considered.

As a countermeasure on the VTR side, it is conceivable to change the system of the VTR so that the tape position becomes constant when the cassette is removed from the VTR. For example, there is a method of lowering the position of the tape immediately before the tape is wound around the tape guide 6. However, although it is technically possible to change the system of such a VTR, the realization is very difficult due to the need to support VTRs already on the market and the need to make the same design for each company. Difficult.

[0009] Therefore, countermeasures on the cassette side have been studied. One of them is to make the tape tension extremely low so as not to be affected by the expansion and contraction of the tape. This is possible if the force of the slider spring is reduced. However, it has been found that it is difficult to realize the tape because it prevents the tape from being transported or dropped by applying a certain tension. Therefore, as another method, a method of adjusting the tape position after the cassette is removed from the VTR has been considered. For example, there is a method in which when a cassette is placed in a cassette storage case, the reel is lifted by a rib in the case to adjust the position. This is valid, but needs to be stored in a case.

As described above, in order to take measures using a cassette, it is necessary to prevent the tape from being deformed even when the cassette is stored alone, and an effective method for this is desired.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic tape cassette in which the tape is not deformed even when the cassette is stored alone.

[0012]

According to a second aspect of the present invention, there is provided a magnetic tape cassette comprising a slide member having a curved tape guide, and a bearing at a center of the slide member. The bearing portion has a bearing hole in a part thereof, the bearing hole of the bearing portion is inserted into a shaft erected in the shell of the cassette, and the tape guide is configured to be swingable around the bearing portion, and the tape is provided. The tension applied to the tape suspended from the guide portion is made uniform, and the deformation of the tape is prevented.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION

First Embodiment In the present invention, as shown in FIGS. 1A and 1B, a tape guide 6 is a slide member 6a for suspending and guiding a tape 9.
And a bearing 6 b attached to the shell 3.

The slide member 6a is formed in a semi-cylindrical shape, and the bearing portion 6b is provided integrally with the slide member 6a in a shelf shape on the opposite side of the tape slide surface substantially at the center of the slide member 6a. A bearing hole 6c is provided.

As shown in FIG. 3, the bearing hole 6c has a wide entrance and a narrow central portion to facilitate swinging. But,
The bearing hole 6c may have a straight shape. Also,
Although the bearing hole 6c has a round shape, as shown in FIG. 7, both ends of the tape guide 6 are limited by the wall of the lower shell 3b, and there is no concern about rotation. The material of the tape guide 6 is a high-strength, durable, low-friction engineering plastic, for example, POM (polyacetal).
Further, in order to prevent sticking due to static electricity, a carbon-containing material, for example, Teflon is preferably used.

As a modified example of the tape guide 6, as shown in FIG. 5, a resin 6d made of a material which is stuck to the tape 9 or has a small friction with the tape 9 is used. The composite molding using resin 6e of a material having low friction with the above material is also effective.

Then, as shown in FIGS.
The first shaft 11 is provided integrally with the upper shell 3a. The second shaft 10 includes a large-diameter portion 10a, a small-diameter portion 10b, and a seat 10c. The bearing hole 6c of the tape guide 6 is inserted into the second shaft 10, and the bearing 6b is placed on the seat 10c. .

Then, as shown in FIG. 2, the tip of the first shaft 11 on the upper shell 3a side abuts on the tip of the second shaft 10. Here, the seat 10c of the second shaft 10 and the first shaft 11
Is larger than the diameter of the bearing hole 6c of the tape guide 6, and the small diameter portion 10b is smaller in diameter than the bearing hole 6c, and has a structure sandwiching the bearing 6b of the tape guide 6 as shown in FIG. I have.

The height of the small-diameter portion 10b is slightly larger than the thickness of the bearing portion 6b so that a clearance for swinging is ensured even when the tip of the first shaft 11 and the tip of the second shaft 10 abut. I have.

When the tape guide 6 is applied with tension by a tape, the tape guide 6 is centered on the bearing 6b as shown in FIGS.
As shown in the figure, the tape 9
When the tension on the upper edge side 9a is high, the upper edge side 9a of the tape guide 6 is pulled, and the load on the tape 9 can be reduced. Therefore, when the tape is taken out from the VTR, the balance of the tension in the tape width direction becomes uniform, and the tape can be prevented from being bent or deformed.

In the first embodiment, the tape guide 6 is assumed to be a DV (digital video cassette) or an 8 mm cassette integrally formed with the shell 3. The present invention can also be implemented with a fixed cassette (for example, VHS, BETA, BETACAM, etc.).

Second Embodiment The tape guide 6 in this case has a completely cylindrical shape. A description will be given below with reference to FIG.
Is a cylindrical shape, a bearing 6b is provided at the center as in the first embodiment, and the bearing hole 6c is formed in a rectangular shape so that the tape guide 6 does not rotate. Therefore, the small diameter portion 10b of the second shaft 10 provided on the shell 3 is also rectangular.

[0023]

According to the present invention, deterioration of image quality and sound quality due to storage of the cassette is prevented, reliability of the cassette is improved, and deformation of the tape after normal use is reduced, and reliability of the cassette is improved. Further, since the tape guide is a separate member, its material and shape can be arbitrarily changed, and tapes having different characteristics can be used in the same cassette.

[Brief description of the drawings]

FIG. 1A is a perspective view of a tape guide of a magnetic tape cassette according to a first embodiment of the present invention, and FIG.

FIG. 2 is an axial side sectional view of a tape guide of the magnetic tape cassette according to the first embodiment of the present invention.

FIG. 3 is a side sectional view of a tape guide of the magnetic tape cassette according to the first embodiment of the present invention.

FIG. 4 is a sectional side view of the magnetic tape cassette according to the first embodiment of the present invention in a state where a tape guide is assembled.

5A is a perspective view of a tape guide of a magnetic tape cassette according to a modification of the present invention, and FIG.

FIG. 6A is a perspective view of a tape guide of a magnetic tape cassette according to a second embodiment of the present invention, FIG.
(C) Top view.

FIG. 7 is a partially cutaway view of the magnetic tape cassette according to the first embodiment of the present invention, (a) a perspective view before assembling a tape guide, and (b) a perspective view after assembling.

FIG. 8 is a side view showing the operation of the tape guide of the magnetic tape cassette of the present invention.

9A is a perspective view of the magnetic tape cassette as viewed from above, and FIG. 9B is a perspective view of the magnetic tape cassette as viewed from below.

FIG. 10 is an exploded view of the magnetic tape cassette.

11A is a sectional side view of the magnetic tape cassette when it is mounted on a VTR, and FIG. 11B is a sectional side view when it is taken out of the VTR.

[Explanation of symbols]

1a, 1b ... reel, 1c ... reel base, 2 ... lid, 2
a ... top lid, 2b ... back lid, 2c ... front lid, 3 ... shell, 3a ... upper shell, 3b ... lower shell, 4 ... reel lock member, 4a ... reel lock slider, 4b1, 4b2 ... reel lock, 4c ... Reel lock spring, 5: slider spring, 6: tape guide, 6a: slide member, 6b: bearing, 6c ...
Bearing holes, 6d, 6e: resin, 7: screw, 8: IC module, 9: tape, 10: second shaft, 10a: large diameter portion,
10b: small diameter portion, 10c: seat, 11: first shaft

Claims (5)

[Claims] 1. A magnetic tape cassette, wherein a tape guide for guiding a magnetic tape in the cassette is movable according to a tension applied to the tape. 2. The tape guide includes a slide member having a curved surface, the slide member includes a bearing portion at a central portion, the bearing portion includes a bearing hole at a part thereof, and the tape guide is provided on a shaft standing upright on a shell of a cassette. The magnetic tape cassette according to claim 1, wherein a bearing hole of the bearing portion is inserted, and the tape guide is swingable about the bearing portion. 3. The magnetic tape cassette according to claim 2, wherein the slide member of the tape guide has a semi-cylindrical shape. 4. The magnetic tape cassette according to claim 2, wherein the slide member of the tape guide has a cylindrical shape. 5. The magnetic tape cassette according to claim 2, wherein a bearing hole of a bearing portion of the tape guide is rectangular.