JPS6168783A - Tape cassette - Google Patents

Abstract

PURPOSE:To prevent tape running defects by forming a block guiding a tape with a synthetic resin containing a ceramic having Mohs hardness of <=8 separately from the casing to keep accurately the verticality of a guide part. CONSTITUTION:A cassette casing 10 is formed by a synthetic resin, the guide block 17 guiding tape running is formed with a synthetic resin containing a ceramic separately from the casing 10 and the Mohs hardness of the ceramic is <=8. In forming the block 17 with the material like this, since the wear of a metal mold is very less even with the number of shots increased, the dimensions of the block 17 is kept accurate. Thus, the verticality of the tape guide is kept with very high accuracy, the vibration of a tape is prevented and defective tape running is avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field This article relates to a tape cassette made of

K. BACKGROUND TECHNOLOGY AND PROBLEMS] For example, tape cassettes have been widely used when recording and/or reproducing information using a tape recorder. In this tape cassette, a magnetic tape is wound around a reel, and the reel is housed in a casing made of a synthetic tM resin molding.

Store such a tape cassette in a tape recorder,
Recording and/or reproduction is performed by running the magnetic tape and bringing it into contact with a magnetic head inserted through a head insertion opening in the casing.

In such a tape cassette, a guide means for guiding the running of the magnetic tape has conventionally been provided integrally with the casing. Therefore, the magnetic tape runs and comes into contact with the head while being guided by the guide means integrated with such a casing. It is preferable that the part constituting the guide means for such a magnetic tape has an accurate vertical surface. However, in conventional tape cassettes, since a mold handling slope is required during molding of the casing, it is difficult to have an accurate vertical surface. Unable to obtain proper verticality,
There have been problems such as the magnetic tape not running in an accurate straight line, resulting in poor running or phase shifts.

Furthermore, in conventional tape cassettes, since the part that guides the magnetic tape is provided on one of the pair of cassette halves, the tape guide is supported in a cantilevered manner, which causes problems due to the tension of the tape. There is a drawback that the tape guide is easily bent due to the pressing force from the tape to the guide, and this bending is coupled with fluctuations in tape tension, causing the guide to bend and move.

This drawback of conventional tape cassettes is due to the fact that the guide section is formed integrally with the half that constitutes the cassette casing, as described above. For example, Japanese Patent Application Laid-open No. 59-124073 discloses forming a wafer.

Here, a composite material of ceramic and synthetic resin is used as the guide block, and the characteristics required for the tape guide are achieved by selecting this material.

However, although the guide block is separate from the conventional cassette casing, it has the disadvantage that the mold used to mold the guide block is easily worn out due to the high hardness of its ceramic material. Ta. As a result, the mold wears out during repeated molding operations, and the dimensions of the guide plotter become too large, eventually making it impossible to guarantee the desired accuracy. This means that industrial production is not possible.

KObject of the Invention 1 The present invention has been made in view of the above-mentioned problems, and it maintains the part of the tape guide that guides the running of the tape-shaped recording medium at a high degree of perpendicularity, thereby preventing running defects and phase-shifting. This prevents misalignment, prevents bending vibration of the tape guide caused by the tension of the tape-shaped recording medium, and prevents wear of the mold during molding of the guide block in which the tape guide is installed. It is an object of the present invention to provide a tape cassette in which guide blocks are industrially produced repeatedly with high dimensional accuracy and have a length of one width.

K Summary of the Invention] The present invention involves winding a tape-shaped recording medium around a reel, storing the reel in a casing, and causing the tape-shaped recording medium to run and come into contact with a head for recording and/or reproduction. In the tape cassette, the casing is molded from synthetic resin, and a guide block for guiding the traveling of the tape-shaped recording medium is molded separately from the casing from synthetic resin containing ceramic. The present invention relates to a tape cassette characterized in that the Mohs hardness of the ceramic is 8 or less, in which the guide block is configured separately from the casing to prevent running defects and phase shifts of the tape-shaped recording medium. In addition, by suppressing the initial occurrence of deflection of the guide block, and by controlling the Mohs hardness of the ceramic contained in this guide block to 8 or less, wear of the mold used to mold the guide block is prevented. It is.

EXAMPLES The present invention will be described below with reference to illustrated embodiments. FIG. 1 shows a tape cassette which is applied to an embodiment of the invention which will be described later, and this tape cassette is equipped with a cassette casing 10. As shown in FIG. The casing 10 is composed of a pair of upper and lower halves 11 and 12 made of synthetic resin, and by joining these halves to each other and using screws, the casing 10 in the shape of a flat rectangular parallelepiped can be assembled. There is. A pair of reels 13, 14 are arranged within the casing 10. These reels 13, 14 are connected to an annular protrusion 2 formed in the casing 10.
8 and both ends of the magnetic tape 15 are fixed to these reels 13.14, and the magnetic tape 15 is wound around the reels 13.14.

The magnetic tape 15 stored in the casing 10 while being wound around the reels 13 and 14 in this manner is guided by a pair of guide rollers 16 and a guide block 17, and is stretched along the front side of the casing 10. It's becoming kind.・The guide block 17 is the casing 10
The front wall of the casing 10 has three tape guides 18, 19, and 20 on the left and right sides, and has a head insertion port 21 and a pinch roller insertion port 22, respectively. It is arranged inside the section. Note that the guide block 17 is formed with a pair of circular protrusions 29 on the upper and lower sides, and these protrusions 29 are adapted to be engaged with circular holes 30 formed in the cassette halves 11 and 12, respectively. As a result, the guide block 1 inside the cassette casing 10
7 is held in the correct position.

In this way, the tape guide 18.1 of the guide block 17
The magnetic tape 15 guided by 9.20 is pushed toward the front side by the felt pad 25 held by the shield plate 23 via the leaf spring 24, and thereby the magnetic head inserted from the head insertion port 21 is pushed forward. It has come to be confronted with. And such magnetic tape 15
In order to make the running of the reels smoother, slippery sheets 26 are arranged above and below the reels 13 and 14, respectively.

These slippery sheets 26 are provided with protrusions 27 on their surfaces, and these protrusions 27 elastically press the tti 115 in the width direction of the magnetic tape 15, so that the magnetic tape Enables smooth running of 15.
are doing.

The cassette casing 10 consisting of the pair of halves 11 and 12 is formed from a synthetic resin molded body, such as conventional synthetic resin, such as high-impact styrene resin, ABS resin, and As resin. On the other hand, although it is separate from the casing 1o, the id block 17
is molded from a material that is a mixture of synthetic resin and ceramic.

FIG. 2 shows a mold for molding this guide block 17, and the guide block 17 is molded by a pair of upper and lower molds 32 and 33.

That is, for example, the guide block 17 is molded by injecting a synthetic resin containing ceramic into the cavity 34 through a resin injection port 35 formed in the upper mold 32 and solidifying it.

When the guide block 17 is molded using a mold as shown in FIG. 2, the material of the guide block 17 may be a combination of various ceramics and synthetic resins as shown in Table 1.

That is, as a ceramic, zinc oxide (Example 1.2
．． 3.4.6.7.8.11), silica-alumina ceramic (Example 2.3.8.9), @barium acid (Example 5), calcium carbonate (Example 10), mica (Example Various ceramics such as 11) can be used. In addition, as a synthetic resin combined with such a ceramic material, 12 nylon (Example 1.2.3.4.5.11)
, 6 nylon (Example 7.8.9.10), polyoxymethylene (Example 6) and other synthetic resin materials can be used.

The guide blocks 17 molded with the composition shown in the composition column of Table 1 were measured for each of Examples 1 to 11 for density, dynamic elastic modulus, resonance sharpness, and Mohs hardness of the ceramic material. These results are as shown in Table 1. In addition, Comparative Example 1 is
This figure shows the measurement results of a conventional tape cassette in which the cassette casing is made of high-impact styrene and the tape guide part is integrally molded into the casing. Comparative Example 2 shows the values obtained when the guide block was molded from a material in which mullite ceramic was mixed into nylon 6. In this comparative example, it should be noted that the Mohs hardness of the mixed ceramic is 9.0, and that
The hardness of 11 is outside the range of 8 or less.

As is clear from the results in Table 1, the guide blocks 17 according to Examples 1 to 11 have a ceramic material with a Mohs height of 8 or less, so that the molding shown in FIG. It becomes possible to prevent wear of the molds 32 and 33. As is clear from the graph shown in FIG. 3, when the guide block 17 is molded using the material according to the embodiment of the present invention, the degree of wear of the mold increases even when the number of shots increases. The amount of wear is very small,
Therefore, the thickness of the guide block 17 to be molded does not increase, and the guide block 17 can be molded repeatedly and continuously with high accuracy. Note that FIG. 3 shows the gold difference when the guide block 17 was molded using the material of Example 3 (indicated by the solid line) and when the guide block 17 was molded using the material of Comparative Example 2 (indicated by the dotted line). It shows the change in the thickness of the guide block 17 due to wear of the mold.

Furthermore, in the tape cassette according to this embodiment, since the guide block 17 is separate from the cassette casing 10, it is possible to make the surfaces of the guide portions 18, 19, and 20 highly accurate perpendicularity. Therefore, the tape runs accurately in a straight line, and poor running and phase shifts can be prevented. Furthermore, the guide block 17 is
Since it is not connected to one of the halves 11 or 12, the guide portions 18, 19, 20 of the idle block 17 will not be deflected due to fluctuations in tape tension and will not cause movement.

The dynamic elastic modulus of the guide block 17 according to Examples 1 to 11 is as shown in Table 1, and has a relatively high dynamic elastic modulus. Therefore, this increases the rigidity and prevents flexure shooting. Furthermore, as is clear from the results in Table 1, the resonance sharpness is lowered and the tape guide 18.
It becomes possible to absorb vibrations of 19.20 degrees, and it also becomes possible to absorb vibration energy by increasing its density. Therefore, the guide book 17 according to this embodiment can improve acoustic characteristics such as modulation noise and phase.

Considering these various characteristics comprehensively, the proportion of thermoplastic resin in the guide block 17 is 30% by weight.
It is preferable that the ceramic material is less than or equal to 50% or more. The guide block 17 molded from such a material has an elastic modulus of 2.0 to 9.
．． Ox 10'N/T[12, resonance sharpness is 5~
45, and the density is 1400 to 3000
Preferably, the value is kg/m3.

K Effects of the invention Moreover, the Mohs hardness of the ceramic is 8 or less. Therefore, according to the present invention, it is possible to obtain a guide block having a guide portion that can guide the running of a tape-shaped recording medium with high precision, and prevents running defects and phase shifts of the tape-shaped recording medium, and It becomes possible to prevent bending vibration. Furthermore, since the guide block is molded from synthetic resin containing a ceramic material with a Mohs hardness of 8 or less, it is possible to prevent mold wear, and the guide block can be repeatedly and repeatedly manufactured with high dimensional accuracy. It becomes possible to mold.

[Brief explanation of the drawing]

Fig. 1 is an exploded perspective view showing a tape cassette applied to an embodiment of the present invention, Fig. 2 is a vertical sectional view of a mold for molding the guide block of this tape cassette, and Fig. 3 is a wear and tear of this mold. This is a graph showing the situation. In addition, in the symbols used in the drawings, 10-...Φ order, cassette casing 15...
. . . Cap magnetic tape 17 . . . Guide blocks 18, 19, 20 . . . Tape guides.

Claims (1)

[Claims] A tape cassette in which a tape-shaped recording medium is wound around a reel, the reel is housed in a casing, and recording and/or reproduction is performed by making the tape-shaped recording medium run and come into contact with a head, The casing is molded from a synthetic resin, and a guide block for guiding the traveling of the tape-shaped recording medium is molded separately from the casing from a synthetic resin containing ceramic, and the Mohs hardness of the ceramic is 8. A tape cassette characterized by the following.