JPH0528706A - Tape cassette - Google Patents

Abstract

(57) [Abstract] [Object] The present invention can suppress an increase in dropout in a tape cassette storing a tape capable of recording and reproducing information such as music and images, and further, the tape can be stably run. It is an object of the present invention to provide a tape cassette that can be produced and has a small fluctuation in reproduction output level and that has a low manufacturing cost. [Structure] A pair of main body cases 4 and 5, a slider 10 for opening and closing case windows, a tape guide 1 sliding on the back side of a magnetic tape 3, a hub 6 and a guide roller 7. The pair of left and right guide posts 12 are formed separately from each other, and at least the tape guide 1 and the guide post 12 are formed of an ultra-high density polyethylene resin mixed with whiskers.
Has a surface roughness of at least 3 which slides on the magnetic tape 3.
It is characterized in that it is in the range of S to 20S.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape cassette that accommodates a tape capable of recording and reproducing information such as music and images and has a slider that opens and closes a window of a main body case, and particularly suppresses an increase in dropout. The present invention relates to a tape cassette in which fluctuations in reproduction output level are reduced.

[0002]

2. Description of the Related Art In a tape cassette containing a magnetic tape (hereinafter abbreviated as "tape"), a lower case 4 has two guide rollers 7 as shown in FIG. A tape guide 1 having a pair of left and right guide portions 1a, 1b, 1c is provided between 7 and 7. Further, a pair of left and right guide pins 2 are provided between the hub 6 and the guide roller 7. Conventionally, the tape guide 1 and the guide pin 2 and the body case 4 are integrally molded, and the molding material is, for example, a thermoplastic resin such as ABS resin or polystyrene resin.

[0003]

In recent years, with high density recording of magnetic recording, tape dropout becomes a fatal defect. Therefore, in Japanese Patent Application No. 1-321715, the window of the main body case has a slider. A tape cassette that can be opened and closed at is proposed. As a result, it is possible to prevent dust from entering the main body case from the outside of the main body case, and it is possible to suppress an increase in dropout significantly as compared to the conventional tape cassette without a slider as shown in FIG. It has become possible.

However, in the tape cassette of Japanese Patent Application No. 1-321715, like the conventional tape cassette, the tape guide 1 and the guide pin 2 and the main body case 4 are integrally molded. As a material, for example, a thermoplastic resin such as an ABS resin or a polystyrene resin is used. When reproduction is performed with such a tape cassette, the back surface of the tape is removed at a total of 8 positions of the guide portions 1a, 1b, 1c in the tape guide 1 and the guide pin 2 between the hub 7 and the guide roller 7 when the tape 3 is running. There was a serious problem that shavings were generated from the sliding surface when the tape was sliding, and the dropout increased as the number of tape passes increased.

Further, since the frictional resistance on the sliding surface during tape running is large, the tape running speed fluctuates,
There is a fatal defect in product quality that this appears as a fluctuation in reproduction output level.

The present invention solves such conventional problems, provides a tape cassette capable of suppressing an increase in dropout, stably running a tape, and having a small fluctuation in reproduction output level, and has a low manufacturing cost. To supply a tape cassette.

[0007]

In order to solve the above problems, a tape cassette according to the present invention comprises a main body case, a slider for opening and closing a case window, a tape guide sliding on the back side of a magnetic tape, and a hub. A pair of left and right guide posts arranged between the guide roller and the guide roller are separate bodies, or the tape guide and the guide post are integrally formed, and at least the tape guide and the guide post are super-high in which whiskers are mixed. The surface roughness of at least the surface of the tape guide and the guide post that slides with the magnetic tape is 3S to 20 which is molded from a density polyethylene resin.
It is characterized by being in the range of S.

[0008]

With the above structure, the sliding characteristics of the tape guide and the guide post are improved, so that the sliding surfaces of the tape guide and the guide post with respect to the back surface of the tape are much less likely to be worn when the tape is running. , It is possible to suppress the increase of dropout. Further, since the sliding characteristic is improved, the reproduction output level fluctuation can be made extremely small.

[0009]

Embodiments of the present invention will be specifically described below with reference to the drawings. As shown in FIG. 1, the tape cassette according to the present invention has a structure in which a main body upper case 5, a main body lower case 4, a tape guide 1, a pair of left and right guide posts 12 and a slider 10 are separate bodies. is there. Further, it has a hub 6 and a guide roll 7 like the conventional tape cassette. The tape guide 1 has a guide portion 1
a, 1b, 1c with a shield 9 in the center.
And the pad 8 is inserted. The guide post 12 is a hollow cylinder, and is inserted into the shaft 11 provided in the lower case 4 of the main body,
Moreover, the lower case 4 of the main body and the upper case 5 of the main body are sandwiched and fixed. Further, as a detent for the guide post 12, a convex portion is provided on the guide post 12 and a concave portion is provided on the lower case side. The relationship between the convex portion and the concave portion may be the reverse of the above-described configuration.

Although the tape guide 1 and the guide post 12 are shown as separate bodies in FIG. 1, for example (FIG. 3).
As shown in, the tape guide 1 and the guide post 12 may be integrated. In this case, the shaft 11 of the lower body case 4 shown in FIG. 1 is not provided.

In the tape cassette constructed as described above, since the dropout does not increase with an increase in the number of tape passes and the reproduction output level fluctuation is reduced, the inventors of the present invention use the tape guide 1 and the guide post 12.
We have made extensive studies on the material. As a result, they have found that the object of the present invention can be almost achieved by molding with an ultra-high density polyethylene resin mixed with whiskers such as zinc oxide. However, as a result of further detailed studies on tape cassettes using the above materials, it was found that it was not possible to completely solve the problems of increased dropout and playback output level fluctuations only by specifying the material. did. Therefore, the present inventors have further earnestly studied the surface roughness of the tape guide 1 and the guide post 12. As a result, they have found that the object of the present invention can be achieved if the surface roughness is in the range of 3 S or more and 20 S or less in addition to the above-mentioned materials. The present inventors initially thought that it is preferable that the surface roughness be as small as possible. However, the above-mentioned surface roughness is obtained when the mold is subjected to so-called embossing, such as zinc oxide. In the case of molding with ultra-high density polyethylene resin mixed with whiskers, there was no choice but to change the conventional idea. When the surface roughness is larger than this range, when the tape slides, shavings are generated on the sliding surface with the tape, and dropout increases. If the surface roughness is less than this range, the tape may stick to the sliding surface, resulting in extremely high friction resistance and unstable tape running, resulting in large fluctuations in the playback output level and further sticking. It was found that shavings were also generated due to the effect of the phenomenon and dropout also increased.

The body cases 4 and 5 are made of ABS resin,
The slider 10 is made of polystyrene or the like, and the slider 10 is made of stainless steel or polyacetal or polyethylene. The hub 6 and the guide roll 7 are formed of, for example, polyacetal or the like.

In the tape cassette according to the present invention having the above structure, the tape guide 1 and the guide post 12 are
The results of measuring the dropout of a tape cassette molded from an ultra-high density polyethylene resin mixed with zinc oxide whiskers are shown in (Table 1), and the results of measuring the level fluctuation are shown in (Table 2). At least the surface roughness of the sliding surface of the magnetic tape of the tape guide and the guide post is 9S.
Dropout is measured once as the number of tape passes,
The measurement was performed every 50 times and 100 times, and the dropout was 1 msec and -6 as the reproduction output.
Those having a size of dB or more were detected. The reproduction output fluctuation was measured by recording at a recording signal frequency of 48 KHz and a recording time of 1 minute at three points along the entire tape length, examining the envelope of the reproduced waveform, and measuring the difference between the maximum and the minimum.

As a comparative example, the tape guide 1 and the guide post 12 are made of the same resin as that of the body cases 4 and 5 made of AB.
The result of the same measurement as described above for the molded product of S resin is shown in (Table 1) and (Table 2).

[0015]

[Table 1]

[0016]

[Table 2]

As shown in (Table 1) and (Table 2), it can be seen that the tape cassette according to the present invention has an excellent effect in suppressing the increase in dropout and reducing the fluctuation in reproduction output level.

[0018]

As described above, according to the tape cassette of the present invention, it is possible to make the reproduction output level fluctuation extremely small without increasing the dropout with the increase of the number of times of the tape pass, and to significantly improve the product quality. It became possible to do. Further, by separating the tape guide and the guide post from each other, the upper and lower cases of the main body can be molded with a resin such as ABS or PS, which has a low cost, so that the cost of the product can be significantly reduced without impairing the effects of the present invention. Became possible.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a tape cassette according to an embodiment of the present invention.

FIG. 2 is a perspective view of a tape guide.

FIG. 3 is an exploded perspective view of a conventional tape cassette.

[Explanation of symbols]

1 Tape guide 2 guide pins 3 tapes 4 Lower body case 5 Upper case 6 hubs 7 Guide roller 8 pads 9 shield 10 slider 11 axes 12 Guide post

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Ohata             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd.

Claims (6)

[Claims] 1. A main body case, a slider that opens and closes a case window, a tape guide that slides on the back side of a magnetic tape, and a pair of left and right guide posts that are arranged between a hub and a guide roller are separate from each other. Body, or only the tape guide and the guide post are integrally formed, and at least the tape guide and the guide post are formed of ultra-high density polyethylene resin mixed with whiskers, and at least the magnetic tape of the tape guide and the guide post is formed. A tape cassette characterized in that the surface roughness of the sliding surface is in the range of 3S to 20S. 2. A pair of left and right guide posts arranged between the hub and the guide roller are hollow cylinders, and the hollow cylinders are inserted into a shaft provided on the body case side. The tape cassette according to claim 1. 3. The tape cassette according to claim 1, wherein the tape guide and the guide post are formed of ultra-high density polyethylene resin. 4. The tape cassette according to claim 1, wherein the whiskers are zinc oxide whiskers. 5. The tape cassette according to claim 1, wherein the whiskers are potassium titanate whiskers. 6. The surface roughness of at least the surface of the tape guide and the guide post that slides on the magnetic tape is 7S to 12S.
The tape cassette according to claim 1, wherein