JPH10255437A - 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 slide part 6 for suspending and guiding a tape.
A tape guide 6 having a cavity 6b and a pivot 6c at the bottom 6d is provided at the center of a, a receiving hole for inserting the pivot 6c of the tape guide 6 is provided at the lower shell, and the pivot 6 is provided at the receiving hole.
Then, the biasing means (coil spring 11) was housed in the cavity 6b of the slide portion 6a, and the upper portion of the tape guide 6 was covered with the upper shell so that the tape guide 6 could move according to the tension of the magnetic tape. [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 construction of a video tape cassette for recording / reproducing, among magnetic tape cassettes, is shown in FIG.
(A) and (b) in appearance, a reel 1 on which a magnetic tape (hereinafter referred to as a tape) is wound, a tape guide for deciding a position where the tape is to be pulled out, and a rotation lock of the reel for preventing tape bulging. It comprises a reel lock member for applying a certain tension, a lid 2 for protecting the tape, a reel spring for stabilizing the rotation of the reel 1, an upper shell 3a, a lower shell 3b, and the like.

More specifically, in FIG. 7, which is an exploded view of a DV (digital video) cassette with an IC module, a reel lock member 4 of this cassette includes a reel lock slider 4a, reel locks 4b1, 4b2, and a reel lock spring 4c. The slider spring 5 is attached to the four points, and the slider spring 5 is fixed to the upper shell 3a and the lower shell 3b to enable the 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,
The reel 1b is lifted by the reel base 1c, the reel 1 rotates so as not to contact the upper shell 3a and the lower shell 3b, and the tape 9 is pulled out to run (see FIG. 8A). On the other hand, at the time of ejection, the reel 9 c is lowered after the tape 9 pulled out is rewound, and the tape 9 is suspended on the tape guide 6. The lock member 4 is returned to lock the reel 1, and the lid 2 is closed and taken out.

For this reason, as shown in FIG. 8B, the tape height position of the tape 9 wound around the reel 1 becomes lower than the tape height position wound around the tape guide 6, and the tape upper edge side 9a is pulled. Therefore, the tape tension is high and the lower edge side 9b is low, resulting in uneven tension in the width direction. When 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 further affected by the expansion and contraction of the tape 9, and FIG.
As shown in (1), the tape 9 is likely to bend, and it becomes 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. The following two countermeasures were considered as measures against this problem.

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 against 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.

[0010]

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.

[0011]

According to a first aspect of the present invention, there is provided a magnetic tape cassette comprising a tape guide provided with a hollow at the center of a slide portion for guiding the tape by suspending the tape and a pivot at the bottom. Then, a receiving hole for inserting the pivot of the tape guide is provided in the lower shell, the pivot is inserted into the receiving hole, a biasing means such as a coil spring is stored in the cavity of the slide portion, and the upper portion of the tape guide is covered with the upper shell, The tape guide moved as the magnetic tape tensioned.

According to the magnetic tape cassette of the present invention, when the magnetic tape cassette is mounted on the recording / reproducing apparatus, the operating member is inserted through the receiving hole of the magnetic tape cassette and the pivot of the tape guide is pushed up. Then, the tension applied to the magnetic tape was made uniform.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a preferred embodiment of the present invention will be described with reference to FIGS. First, as shown in FIG. 1, a tape guide 6 used in the magnetic tape cassette of the present invention is provided with a hollow portion 6b for inserting a coil spring in a slide portion 6a having a semicircular cross section for suspending and guiding the tape, and a hollow portion 6b is provided at the lower end. The bottom 6d is provided with a convex pivot 6c.

The height h1 of the pivot 6c is equal to the height of the lower shell 3b.
, So as not to protrude from the outer surface of the lower shell 3b. The pivot 6c and the lower shell 3
The shape of the receiving hole 12 of b may be square so as not to rotate. The material constituting the tape guide 6 is AB
The same material as that used for the shell such as S and POM may be used. However, in order to prevent sticking due to static electricity, it is also effective to use a material containing carbon, for example, a Teflon-based material.
Further, it may be made of a hardly magnetizable metal such as SUS-304.

On the lower shell 3b side, as shown in FIG.
A receiving hole 12 penetrating through the wall of the lower shell into which c enters is provided, and a semi-arc-shaped rib 13 for surrounding and positioning the outside of the tape guide 6 is provided around the receiving hole 12. is there. The inner diameter of the rib 13 is slightly larger than the outer diameter of the tape guide 6 so that the tape guide 6 can move within it. FIG. 3 shows the appearance of the tape guide 6 attached to the upper and lower shells 3a and 3b. The upper end of the tape guide 6 is closed by the front edge 3a1 of the upper shell 3a. It is not necessary to cover the entire upper end of the tape guide 6 with the upper shell 3a, and it is sufficient that the tape guide 6 has an area that can be held by the coil spring 11.

As shown in FIG. 4, which is a cross-sectional view taken along the line BB of FIG. 3, a pivot 6c provided at the bottom 6d of the tape guide 6 is inserted into the receiving hole 12 with a margin.
It can be moved up and down. Further, a coil spring 11 is inserted into the cavity 6b of the tape guide 6, and the upper end of the coil spring 11 abuts against the inner surface of the upper shell 3a.
Is pressed against the lower shell 3b. The gap between the end face of the tape guide 6 and the upper shell is set to a dimension that allows the tape guide 6 to move up and down.
0 is inserted into the upper end of the tape guide 6.

FIGS. 5A and 5B show a case where the cassette is a VTR.
FIG. 4 is a diagram showing a positional relationship between the tape guide 6, the reel 1, and the tape 9 when the tape guide 6 is inserted and when the tape guide is removed from the VTR. In a normal cassette alone, the lower surface of the reel 1 and the lower surface of the tape guide 6 are located at positions C1 and D1, respectively, from the reference surface S of the lower shell 3b. But VTR
When the reel 1 enters, the reel base 14 pushes up the reel 1, and at the same time, the guide base 15 pushes up the pivot 6c of the tape guide 6 inserted through the receiving hole 12, thereby lowering the lower surface of the reel 1 to C2.
And the tip of the pivot 6c is the position of D2.
At this time, the movement amount D2-D1 of the tape guide 6 is the reel 1
Is set to be the same as the movement amount C2-C1.

As a result, when the cassette is ejected from the VTR, the tape 9 pulled out is rewound,
After the tape is suspended on the tape guide 6, the reel base 1
4 and the guide base 15 are lowered by the same amount, and accordingly, the reel 1 and the tape guide 6 are lowered and come into contact with the lower shell 3b. Then, the reel lock is returned to lock the reel 1,
The lid 2 is closed and discharged. Therefore, in the cassette taken out of the VTR, the position of the tape suspended on the tape guide and the position of the tape wound on the reel 1 are at the same height. Thereby, the difference in the tension in the width direction of the tape 9 is eliminated, and the deformation of the tape 9 can be prevented.

[0019]

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, thereby improving reliability of the cassette. 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 of the present invention, FIG. 1B is a sectional view taken along line AA, and FIG.
FIG.

FIG. 2A is a perspective view of a magnetic tape cassette according to the present invention before the tape guide is assembled, and FIG. 2B is a partial perspective view after the tape guide is assembled.

FIG. 3 is a perspective view of a magnetic tape cassette according to the present invention, in which a tape guide is assembled.

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

FIG. 5 is a side sectional view showing the operation of the tape guide of the magnetic tape cassette of the present invention.

6A is a perspective view of the magnetic tape cassette as viewed from above, and FIG. 6B is a perspective view of the magnetic tape cassette as viewed from below.

FIG. 7 is an exploded view of the magnetic tape cassette.

8A is a side sectional view of the magnetic tape cassette when it is mounted on a VTR, and FIG.

FIG. 9 is a side view showing the deformation of the magnetic tape.

[Explanation of symbols]

1 ... reel, 2 ... lid, 2a ... top lid, 2b ...
Back lid, 2c front lid, 3a upper shell, 3a1 front edge, 3b lower shell, 4 reel lock member, 4a reel lock slider, 4b1, 4b
2 ... reel lock, 4c ... reel lock spring, 5
... Slider spring, 6 ... Tape guide, 6a ... Sliding member, 6b ... Cavity, 6c ... Pivot, 6d ... Bottom part, 7 ... Screw, 8 ... IC module, 9 ... Tape, 10
... Groove, 11 ... Coil spring, 12 ... Receiving hole, 13 ... Rib, 1
4 ... reel stand, 15 ... guide stand

Claims (3)

[Claims] 1. A tape guide provided with a cavity and a pivot at the bottom at the center of a slide part for suspending and guiding a tape, and a receiving hole for inserting the pivot of the tape guide is provided at a lower shell; The pivot is inserted into the hole, the biasing means is housed in the cavity of the slide portion, the upper portion of the tape guide is covered with an upper shell, and the tape guide is moved according to the tension of the magnetic tape. A magnetic tape cassette characterized by the following. 2. The magnetic tape cassette according to claim 1, wherein when the magnetic tape cassette is mounted on the recording / reproducing apparatus, an operating member is inserted through the receiving hole of the magnetic tape cassette to push up the pivot of the tape guide. The magnetic tape cassette as described. 3. The magnetic tape cassette according to claim 1, wherein the tape guide is formed of carbon-containing plastic.