JPH0547151A - Tape cassette - Google Patents

Abstract

(57) [Summary] [Purpose] To supply a tape cassette that can suppress the increase of dropouts, can stably run the tape, and have a small fluctuation in the reproduction output level, and a low manufacturing cost. In a tape cassette having a main body case and a slider 10 for opening and closing a window of the main body case, at least a tape guide 2 that slides on the back side of a magnetic tape 3 is a material different from that of the main body case. When,
As a sliding aid, a polyacetal resin mixed with fluorine, a polyolefin resin mixed with whiskers, an aromatic polyamide resin mixed with whiskers and the like are fixed to the main body case by insert molding, and at least the magnetic tape 3 of the tape guide 2. Surface roughness of sliding surface is 0.3
It is characterized by being in the range of S to 2S.

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 with a small fluctuation in reproduction output level.

[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 pair of left and right tape guides 1a, 1b, 1c are provided between 7 and 7, and a pair of left and right tape guides 1d are provided between the hub 6 and the guide roller 7.
Conventionally, the tape guide and the main 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, dust can be prevented from entering the main body case from the outside of the main body case, and the increase in dropout can be significantly suppressed as compared with the conventional tape cassette without a slider as shown in FIG. It has become possible.

However, the tape cassette of Japanese Patent Application No. 1-321715 is formed by integrally molding the above-mentioned tape guide 1 like the conventional tape cassette, and the molding material is, for example, ABS resin or polystyrene. It was molded with a thermoplastic resin such as resin. When reproduction is performed with such a tape cassette, shavings are generated from the sliding surface when the back surface of the tape slides in the tape guide 1 when the tape 3 is running, and dropout increases as the number of tape passes increases. There was a serious problem going on. Further, there is a fatal defect in product quality that the running speed of the tape fluctuates due to a large frictional resistance on the sliding surface during running of the tape, which appears as a fluctuation in reproduction output level.

Further, there is a method in which the tape guide is formed separately from a material having excellent tape sliding properties, such as polyacetal. This is a so-called three-piece structure, and although this improves the sliding characteristics with respect to the tape, there is a problem that the number of parts increases and the number of assembling steps also increases, resulting in an increase in cost.

The present invention solves the above-mentioned conventional problems, provides a tape cassette which can suppress the increase of dropout, can stably run the tape and has a small fluctuation in the reproduction output level, and further has a low manufacturing cost. To supply a tape cassette.

[0007]

In order to solve the above-mentioned problems, the tape cassette of the present invention has a slider for opening and closing the window of the main body case, and the tape guide which slides at least on the back side of the magnetic tape is described above. The tape guide is made of a thermoplastic resin different from that of the main body case, and at least the sliding surface of the tape guide has a surface roughness of 0.3S to 2S.
It is characterized by being in the range of. Furthermore, the present invention is characterized in that the tape guide is fixed to the main body case by insert molding.

Further, the present invention is characterized in that the tape guide is fixed by being press-fitted into the main body case.

Further, the present invention is characterized in that the tape guide is fixed to the main body case by welding.

Further, the present invention is characterized in that the thermoplastic resin of the tape guide is a polyacetal resin containing whiskers and fluorine as a sliding aid.

The present invention is also characterized in that the thermoplastic resin of the tape guide is a polyolefin resin containing whiskers.

The present invention is also characterized in that the thermoplastic resin of the tape guide is an aromatic polyamide containing whiskers.

Further, the present invention is characterized in that the whiskers are zinc oxide whiskers.

Further, the present invention is characterized in that the whiskers are potassium titanate whiskers.

Further, the present invention is characterized in that the thermoplastic resin of the tape guide is a polyacetal mixed with carbon.

[0016]

With the above structure, since the sliding characteristics of the tape guide are improved, the sliding surface of the tape guide with the back surface of the tape is less likely to be worn when the tape is running, so that the dropout is increased. Can be suppressed. Further, since the sliding characteristic is improved, the reproduction output level fluctuation can be made extremely small.

Further, since the tape guide can be fixed to the main body case by insert molding at the time of molding, the number of assembling steps can be greatly reduced and the cost can be reduced.

[0018]

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 includes resin tape guides 2a, 2b, 2c, 2d, a slider 10 fixed to a lower body case 4 by insert molding with a material different from that of the body case.
And a hub 6, a guide roll 7, a pad 8, a shield 9, and a sliding sheet (not shown).

The tape guides 2a, 2b, 2c and 2d are
The cylindrical resin pin shown in FIG. 2A is partially embedded in the body case 4 and fixed.

In the tape cassette constructed as described above, since the dropout does not increase with an increase in the number of times of tape passes and the reproduction output level fluctuation is reduced, the present inventors have made the tape guides 2a, 2b, 2c ,. 2d
As a result of repeated intensive studies on the material of, the mixture of whiskers such as zinc oxide, polyacetal resin containing fluorine as a sliding aid, polyolefin resin containing whiskers, aromatic polyamide containing whiskers, and carbon It was found that the polyacetal prepared was suitable.

However, as a result of further detailed study on the tape cassette using the above-mentioned material, it is impossible to completely solve the problems of the increase of dropout and the fluctuation of the reproduction output level only by specifying the material. It has been found. Therefore, the present inventors have further developed the tape guides 2a, 2
The inventors have earnestly studied the surface roughness of b, 2c, and 2d.
As a result, it has been found that the object of the present invention can be achieved if the surface roughness is in the range of 0.3 s or more and 2 s or less in addition to the above-mentioned specification of the material. If the surface roughness is larger than this range, the frictional resistance when the tape slides increases, the running of the tape becomes unstable, and the reproduction output level fluctuation increases. Furthermore, shavings are generated on the sliding surface with the tape, increasing dropout. It was also found that when the surface roughness is less than this range, the tape sticks to the sliding surface, the frictional resistance increases, and the tape running becomes unstable, resulting in large fluctuations in the reproduction output level.

In this embodiment, the tape guide 2a,
2b, 2c, and 2d have a structure in which the cylindrical resin pin shown in (FIG. 2a) is partially embedded in the main body case 4 and fixed, but the tape guide is The shape shown in FIG. 2B may be used. Further, as shown in (FIG. 2c), only the curved surface that slides on the magnetic tape may be covered with resin in order to secure the fixation and reduce the cost.

In this embodiment, the tape guide is fixed to the lower case, but the same effect can be obtained by fixing it to the upper case.

The body cases 4 and 5 are made of ABS resin,
Since the tape guide 1 is molded from polystyrene or the like and the tape guide 1 can be fixed to the main body case by insert molding with the above-mentioned material, the tape cassette of the present invention has a significantly lower manufacturing cost than the case where the above-mentioned tape guide is molded and incorporated separately. It became possible to lower.

As another component, the slider 10 is made of stainless steel, polyacetal, polyethylene or the like. 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 resin tape guides 2a, 2b, 2c, 2d are provided.
As the material of the tape cassette, a dropout of a tape cassette using a zinc oxide whisker and a polyacetal resin mixed with fluorine as a sliding aid is measured (Table 1), and the level fluctuation is measured (Table 2). Show. The surface roughness of the sliding surface of at least the magnetic tape of the tape guide and the guide post is 0.5S. The dropout was measured every 1, 50, and 100 times as the number of tape passes, and the dropout was detected as a reproduction output of 1 msec and a size of -6 dB or more. The fluctuation of the reproduction output is measured at a recording signal frequency of 48 KHz and a recording time of 1 minute, and the total tape length is 3
Recording was performed at some points, the envelope of the reproduced waveform was examined, and the difference between the maximum and minimum was measured.

As a comparative example, the tape guides 1a, 1b,
1c and 1d are made of the same resin as the case bodies 4 and 5
The results of measurements made in the same manner as above for those molded with S resin are also shown in (Table 1) and (Table 2).

[0028]

[Table 1]

[0029]

[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 increase in dropout and reducing fluctuation in reproduction output level.

[0031]

As described above, according to the tape cassette of the present invention, the reproduction output level fluctuation can be extremely reduced without increasing the dropout as the number of tape passes increases, and the product quality is remarkably improved. It became possible to do. In addition, the upper and lower cases of the main body are low cost
Since it can be molded with resin such as S or PS, and only the tape guide can be integrated with the body case by insert molding with a different material, the manufacturing cost of the product can be significantly reduced.

[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 partial detailed view of the tape guide according to the embodiment of the present invention. (A) Tape guide made of cylindrical resin (b) Tape guide with a part of a prism as a curved surface (c) Tape guide in which only the curved surface that is in sliding contact with the magnetic tape is covered with resin

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

[Explanation of symbols]

 1a, 1b, 1c, 1d Tape guide 2a, 2b, 2c, 2d Resin tape guide 3 Magnetic tape 4 Main body lower case 5 Main body upper case 6 Hub 7 Guide roller 8 Pad 9 Shield 10 Slider

Claims (10)

[Claims] 1. A tape cassette having a main body case and a slider for opening and closing a window of the main body case, wherein at least a tape guide sliding on the back side of the magnetic tape is made of a thermoplastic resin different from the main body case, The tape cassette, wherein the surface roughness of the sliding surface of at least the magnetic tape of the tape guide is in the range of 0.3S to 2S. (However, the surface roughness is JIS "B0601".
The maximum value of the maximum height specified in 2. The tape cassette according to claim 1, wherein the tape guide is fixed to the main body case by insert molding. 3. The tape cassette according to claim 1, wherein the tape guide is fixed by being press-fitted into the main body case. 4. The tape cassette according to claim 1, wherein the tape guide is fixed to the main body case by welding. 5. The tape cassette according to claim 1, wherein the thermoplastic resin of the tape guide is a polyacetal resin containing whiskers and fluorine as a sliding aid. 6. The tape cassette according to claim 1, wherein the thermoplastic resin of the tape guide is a polyolefin resin mixed with whiskers. 7. The tape cassette according to claim 1, wherein the thermoplastic resin of the tape guide is an aromatic polyamide mixed with whiskers. 8. The tape cassette according to claim 1, wherein the whiskers are zinc oxide whiskers. 9. The tape cassette according to claim 1, wherein the whiskers are potassium titanate whiskers. 10. The tape cassette according to claim 1, wherein the thermoplastic resin of the tape guide is polyacetal mixed with carbon.