JP2001110160A - Magnetic tape cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic tape cassette capable of straightening a developed warpage even if the warpage is developed in upper and lower cassette halves after shaping. SOLUTION: In the magnetic tape cassette wherein a magnetic tape is wound and housed in the upper and lower cassette halves and the height of the space within the cassette is defined by abutting a plurality of bosses for screws provided in the upper cassette half on plural bosses for screws provided in the lower cassette half facing the bosses provided in the upper cassette half in order to connect the upper cassette half to the lower cassette half, the height of the boss 73e for the screw close to the center of at least one side of casing of the upper and lower cassette halves is higher than that of the bosses 73b, 73d for the screws close to both sides of the casing.

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 such as a digital video cassette (DVC).

[0002]

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

Referring to FIG. 3, as a magnetic tape cassette 30 conventionally used for, for example, DVC, a pair of tape reels 31 around which a magnetic tape t is wound are mounted in a lower cassette half 33 paired with an upper cassette half 32. To
Some are rotatably supported.

Tape guides 35 are provided on both sides of the opening 34 in the lower cassette half 33 on the near side in FIG. Each tape guide 35 is sent from one tape reel 31 to the other tape reel 31.
And guides the magnetic tape t to pass through a predetermined position in the opening 34.

On the rear side of the lower cassette half 33, a reel lock member 39 having a tape reel locking arm 38 is provided. Reel lock member 39
Is urged by a compression coil spring 40 to move the tape reel locking arm 38 to each tape reel 3.
The tape reel 31 is engaged with the engaging teeth 41 formed on the outer circumference of the tape reel 1 to prevent the tape reels 31 from being accidentally rotated. This prevents loosening of the magnetic tape t.

An outer lid 50, a top lid 52, and an inner lid 51 that cover the opening 34 of the lower cassette half 33 are respectively attached to the upper cassette half 32 so as to be freely opened and closed.

A lock pin 54 projects from the side plate 53 of the outer lid 50. The lock pin 54 is provided with a lid lock 55 rotatably provided on the lower cassette half 33.
Is locked. Reference numeral 56 denotes a lid spring that biases these lids to a closed state.

[0008]

By the way, when the size of the magnetic tape cassette is increased, the upper and lower cassette halves 32,
If the thickness of 33 is increased in proportion to the increase in the size of the cassette, the internal space of the cassette will be reduced. Therefore, even if the cassette size is increased, the internal space of the cassette is made as large as possible by not increasing the thickness.

However, if the thickness of the upper and lower cassette halves 32 and 33 is not sufficiently large, the upper and lower cassette halves 32 and 33 are deformed due to a warp that becomes convex inward after molding. Sometimes. For example, in the upper cassette half 32 having a window opening, a warp occurs in which the vicinity of the opening bends downward in the cassette.
Further, in the lower cassette half 33 having an opening for driving a tape reel, for example, a warp occurs in which the vicinity of the opening bends above the cassette. Particularly, since the upper cassette half 32 is thinner than the lower cassette half 33, the deformation amount is correspondingly large.

If the upper and lower cassette halves 32 and 33 are warped and deformed, the space in the cassette becomes narrower, which hinders the running of the reels and the function of other operating members. In addition, not only the flatness of the outer shape of the cassette is impaired, resulting in poor appearance, but also the flatness is impaired, which may cause a malfunction in the recording and reproducing apparatus. Furthermore, the peripheral walls of the upper and lower cassette halves 32 and 33 do not contact each other on both sides of the cassette, and a gap may be formed between the upper and lower cassette halves 32 and 33, which may lower the dust resistance.

An object of the present invention is to solve the above-mentioned problem, and to provide a magnetic tape cassette which can correct the generated warpage even if the upper and lower cassette halves are warped after molding.

[0012]

The above object of the present invention is achieved by the following constitution. A plurality of screw bosses are provided on the upper cassette half to house the magnetic tape wound in the upper and lower cassette halves and fasten the upper and lower cassette halves, and are provided on the lower cassette half opposite to the screw bosses. The height of the screw boss near the center of at least one of the upper and lower cassette halves in the magnetic tape cassette in which the height of the internal space of the cassette is defined by contact of the plurality of screw bosses A magnetic tape cassette characterized by being higher than the height of the screw boss nearer.

[0013] In the magnetic tape cassette in which the magnetic tape is wound and housed in the upper and lower cassette halves, at least a part of the inner wall defining the magnetic tape housing area in the upper and lower cassette halves has the same height as the peripheral wall of the upper and lower cassette halves. Magnetic tape cassette characterized by being equal.

According to the present invention, the height of the screw boss near the center of at least one of the upper and lower cassette halves is higher than the height of the screw boss near both sides of the case. By tightening with screws, the upper and lower cassette halves exert a fastening force with the screw boss near the center of the case as a fulcrum so that the flat plate portion becomes convex outward, so the upper and lower cassette halves are warped. Even warpage is corrected.

According to the present invention, at least a part of the inner wall defining the magnetic tape accommodating area in the upper and lower cassette halves is equal in height to the peripheral walls of the upper and lower cassette halves. Due to the contact between the inner walls, the internal space between the upper and lower cassette halves is appropriately limited, and even if the upper and lower cassette halves are warped, the warp is corrected.

Therefore, the space inside the case is not narrowed, the flatness of the cassette is maintained, and the dustproofness is not reduced.

In the present invention, the screw boss is preferably provided so as to avoid a center line at the center in the width direction of the upper and lower cassette halves.

According to this configuration, since the upper and lower cassette halves are independently fastened to the left and right regions by the screws with the center line as a boundary, a large number of screws are arranged in a narrow region. Therefore, good flatness is maintained.

In the present invention, it is preferable that the screw boss is provided at an intersection of diagonal lines of the upper and lower cassette halves.

[0020]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a plan view of the lower half of the magnetic tape cassette according to the first embodiment of the present invention. The configuration of the first embodiment is basically the same as that of the conventional magnetic tape cassette shown in FIG. 7, and the different configuration is only the upper and lower cassette halves. Therefore, only the configuration of the upper and lower cassette halves will be described.

FIG. 1 is a plan view of the lower cassette half 33, and FIG. 2 is a sectional view of a fixed portion of the upper and lower cassette halves 32, 33. Screw bosses 72, 73 for combining and fixing the upper and lower cassette halves 32, 33 are formed on the upper and lower cassette halves 32, 33, respectively. As shown in FIG. 2, the upper and lower cassette halves 32 and 33 have screw bosses 7 formed on the upper and lower cassette halves 32 and 33, respectively.
Screws 74 are screwed in from below and fixed in a state where the two 73 are in contact with each other. The screw boss 72 formed on the upper cassette half 32 has a hollow cylindrical shape having a downwardly facing convex portion. The screw boss 73 formed on the lower cassette half 33 has a hollow cylindrical shape having a concave portion into which the convex portion of the screw boss 72 of the upper cassette half 32 fits. The screw bosses 72 and 73 of the upper and lower cassette halves 32 and 33 are fixed by screws 74 in a state where they are in contact with each other and fitted.

As shown in FIG. 1, the lower cassette half 33
, One screw boss 73a, 73b, 73c, 73d is formed before and after each side of the cassette, and one screw boss 73e is formed on the front side of the center of the cassette, and the rear side near the center of the cassette. One screw boss 73
f is formed, and a total of six screw bosses 73a to 73f are formed.

FIG. 3 is a sectional view taken along line AA of FIG. 1, and shows the screw bosses 73b and 73d on the rear side on both sides of the cassette and the screw boss 7373e on the front center side of the cassette. The screw bosses 73b and 73d on both sides have the same height, the central screw boss 73e is higher than the screw bosses 73b and 73d on both sides, and the screw bosses 73b and 73d on both sides and the central screw boss are used. 73e, there is a difference of h in height.

In FIG. 3, the height difference h is exaggerated for easy understanding, and the height difference h is actually:
It is 0.05 mm to 0.1 mm. The screw boss 73f on the rear side near the center of the cassette is also mounted on the screw boss 7 on both sides.
The height is higher than 3b and 73d, and is equal to the height of the screw boss 73e on the front side in the center of the cassette.

As described above, since the height of the screw bosses 73e and 73f near the center of the cassette is higher than the height of the screw bosses 73b and 73d near the both sides of the cassette, the upper and lower cassette halves 32 and 33 are fixed by the screw 74. Then, the upper cassette half 32 is attached to the screw boss 7 near the center of the cassette.
A force is applied so that both sides of the cassette bend downward with 3e and 73f as fulcrums. Further, the lower cassette half 33 receives a force such that both sides of the cassette are bent upward with the screw bosses 73e and 73f near the center of the cassette as fulcrums. Therefore, even when the upper and lower cassette halves 32 and 33 are warped such that the center of the cassette is bent toward the inside of the cassette, the upper and lower cassette halves 32 and 33 are fixed by the screws 74.
The warpage is corrected, and the flatness of the upper and lower cassette halves 32 and 33 is guaranteed.

In the first embodiment, the lower cassette half 3
The height relationship of the screw boss 73 of No. 3 is as described above,
The screw boss 72 of the upper cassette half 32 may have the same configuration. That is, the height of the screw boss 72 near the center of the cassette of the upper cassette half 32 may be higher than the height of the screw boss 72 near both sides of the cassette. In the first embodiment, it is sufficient that at least one of the upper and lower cassette halves 32, 33 has the screw bosses 72, 73 near the center of the cassette higher than the screw bosses 72, 73 near both sides of the cassette. Warpage can be corrected in the same manner as described above.

Next, a second embodiment of the present invention will be described.
FIG. 4 is a plan view of the lower cassette half 33 of the magnetic tape cassette according to the second embodiment of the present invention. The second embodiment is different from the first embodiment in the arrangement of the screw boss 73.

In the lower cassette half 33 in the second embodiment, the screw bosses 73 are arranged so as to avoid the center in the cassette width direction, and the screw bosses 73 are not arranged on the center line.

Two screw bosses 73g and 73h are formed in front of the lower cassette half 33 near the center of the cassette, avoiding the center line. Also, two screw bosses 73f and 73i are formed on the rear side of the lower cassette half 33 near the center of the cassette, avoiding the center line. And these four screw bosses 73g, 73
The heights h, 73f, 73i are higher than the screw bosses 73a, 73b, 73c, 73d on both sides of the cassette, as in the first embodiment.

According to this configuration, similarly to the first embodiment, when the upper and lower cassette halves 32 and 33 are fixed by the screws 74, the upper cassette half 32 is attached to the screw bosses 73g, 73h, 73f and 73i near the center of the cassette. A force is applied so that both sides of the cassette bend downward with the fulcrum as a fulcrum. The lower cassette half 33 receives a force such that both sides of the cassette are bent upward with the bosses 73g, 73h, 73f, 73i near the center of the cassette as fulcrums. Therefore,
Even if the upper and lower cassette halves 32 and 33 are warped such that the cassette center is deflected in the cassette contents, the warp is corrected by fixing the upper and lower cassette halves 32 and 33 with the screws 74 so that the upper and lower cassette halves 32 and 33 are corrected. Flatness is guaranteed.

In addition, the upper and lower cassette halves 32, 33
Since the cassette left and right sides are fixed independently, a large number of screw bosses 73g, 73h, 73f, 7
3i can be arranged, and the warp correcting power is improved.

Next, a third embodiment of the present invention will be described.
FIG. 5 is a plan view of the lower cassette half 33 of the magnetic tape cassette according to the third embodiment of the present invention. The third embodiment differs from the first embodiment in the arrangement of screw bosses 73.

In the lower cassette half 33 of the third embodiment, screw bosses 73j near the center of the cassette have screw bosses 73a, 73b, 73c, 7 near both sides of the cassette.
It is arranged on the intersection of diagonal lines 75 and 76 connecting 3d. The screw boss 73j at the intersection of the diagonal lines 75, 75 is arranged at the center in the cassette width direction.

The upper and lower cassette halves 32, 33 are provided with screw bosses 73a, 73b, 73c, 73 near both sides of the cassette.
The upper and lower cassette halves 32, 32 are fixed by screws 74 using screw bosses 73 j arranged at the intersections of diagonal lines 75, 76 connecting d.
When the screw 33 is fixed by the screw 74, the screwing force on the intersection is balanced with the screwing force at the screw bosses at both ends of each diagonal line, and is mechanically extremely effective, efficient and stable. A fixing force is obtained.

Next, a fourth embodiment of the present invention will be described.
FIG. 6 is a sectional view of a main part of the lower cassette half 33 of the fourth embodiment. The plan view of the lower cassette half 33 of the fourth embodiment is the same as that of the first embodiment shown in FIG. In the fourth embodiment, a part of the inner wall 77 that defines the tape housing area of the lower cassette half 33 has the same height as the peripheral wall 78.

Since the heights of at least a part of the inner wall 77 and the peripheral wall 78 are equal, the upper and lower cassette halves 32, 3
When 3 is fixed with the screw 74, the inner walls 77 of the upper and lower cassette halves 32, 33 abut against each other, and the space in the cassette is appropriately restricted. As a result, the upper and lower cassette halves 3
Even if the central portions of the upper and lower cassette halves 32 and 33 are warped inward, the warp is corrected by fixing the upper and lower cassette halves 32 and 33 with the screws 74.

In the fourth embodiment, a part of the inner wall 77 of the lower cassette half 33 has the same height as the peripheral wall 78. However, the entire inner wall 77 has the same height as the peripheral wall 78. It may be. Further, at least a part of the inner wall of the upper cassette half 32 may have the same height as the peripheral wall. That is, it is sufficient that at least a part of the inner wall 77 of at least one of the upper and lower cassette halves 32 and 33 has the same height as the peripheral wall 78.

Further, at least a part of the inner wall 77 is
The height may be higher than eight. According to this configuration, similarly to the first embodiment, when the upper and lower cassette halves 32 and 33 are fixed by the screws 74, the inner wall 77 is higher than the peripheral wall 78 of the upper and lower cassette halves 32 and 33.
When the two cassettes come into contact with each other, the peripheral walls of the upper cassette half 32 near both sides of the cassette receive a force to bend downward,
The peripheral wall 78 of the lower cassette half 33 near both sides of the cassette receives a force to bend upward, and the upper and lower cassette halves 32,
The warpage of the central part of 33 is corrected.

It should be noted that the present invention is not limited to the above-described embodiment, but can be appropriately changed and improved based on the gist of the present invention. For example, the present invention may be a configuration obtained by combining the configurations of the above embodiments. Further, the present invention is not limited to DVC, but can be applied to any magnetic tape cassette, and the recording / reproducing method, size, etc. are not limited.

[0040]

As described above, according to the first aspect of the present invention,
Since the height of the screw boss near the center of at least one of the upper and lower cassette halves is higher than the height of the screw boss near the both sides of the case, by fastening the upper and lower cassette halves with screws, the screw near the center of the case is tightened. Since the upper and lower cassette halves have a fulcrum as a fulcrum, a fastening force acts on the upper and lower cassette halves so that the flat plate portion is outwardly protruded.

According to the second aspect of the present invention, at least a part of the inner wall defining the magnetic tape accommodating area in the upper and lower cassette halves has the same height as the peripheral walls of the upper and lower cassette halves. When the inner walls of the upper and lower cassettes are in contact with each other, the internal space between the upper and lower cassette halves is appropriately limited, and even if the upper and lower cassette halves are warped, the warpage is corrected.

Accordingly, the space inside the case is not narrowed, the flatness of the cassette is maintained, and the dustproofness is not reduced.

[Brief description of the drawings]

FIG. 1 is a plan view of a lower half of a magnetic tape cassette according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a fixing portion of an upper and lower cassette half.

FIG. 3 is an exploded view of the magnetic tape cassette.

FIG. 4 is a plan view of a lower half of a magnetic tape cassette according to a second embodiment of the present invention.

FIG. 5 is a plan view of a lower half of a magnetic tape cassette according to a third embodiment of the present invention.

FIG. 6 is a sectional view of a main part of a lower half of a magnetic tape cassette according to a fourth embodiment of the present invention.

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

[Explanation of symbols]

 31 Tape Reel 32 Upper Half 33 Lower Half 35 Tape Guide 36 Positioning Hole 45 Boss 72 Screw Boss 73, 73a to 73j of Upper Half Case Screw Boss 74 of Lower Half Case 74 Screw 75, 76 Diagonal Line 77 Connecting Screw Boss 77 Inner Wall 78 Perimeter wall

Claims (2)

[Claims] 1. A plurality of screw bosses provided on an upper cassette half for winding and accommodating a magnetic tape in upper and lower cassette halves for fastening the upper and lower cassette halves, and a lower boss facing the screw bosses. In a magnetic tape cassette in which the height of the space in the cassette is defined by abutting a plurality of screw bosses provided on the cassette half, the height of the screw boss near the center of at least one of the upper and lower cassette halves is adjusted. The magnetic tape cassette is characterized in that the height is higher than the height of the screw boss on both sides of the case. 2. A magnetic tape cassette in which a magnetic tape is wound and housed in upper and lower cassette halves, wherein at least a part of an inner wall defining a magnetic tape housing area in the upper and lower cassette halves is higher than a peripheral wall of the upper and lower cassette halves. A magnetic tape cassette having the same length.