JPH0380486A - Tape cartridge - Google Patents

Abstract

PURPOSE:To suppress the increment of modulation noise and to improve acoustic characteristics by molding a guide block by phenol resin containing glass fiber, improving abrasion resistance and reducing a friction factor between a guide rib and a tape. CONSTITUTION:Guide rolls 5 are arranged on the right and left position of the front end in a body case 1 and the tape 3 is wound from one hub 4 around the other hub 4 through the rolls 5 while passing the front of the case 1. On the other hand, the other guide block 7 for regulating the tap path of the tape 3 is built in the front side of the case 1 with the horizontal length almost corresponding to the distance between the rolls 5, 5 and fixed. The block 7 is formed by phenol resin containing glass fiber to improve abrasion resistance and reduce the friction factor between the guide rib 12 and the tape 3. Consequently, the traveling state of the tape 3 can be smoothed, the occurrence of frequency modulation noise can be suppressed and the acoustic characteristics can be improved.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a tape cartridge that incorporates a separate guide block inside the front side of a main body case. The objective is to reduce frequency modulation noise caused by the system.

[Conventional technology]

For example, in Japanese Unexamined Patent Application Publication No. 1985-5, it was possible to mold this type of tape guide block from a plastic material different from that of the main body case to improve the mechanical properties and friction coefficient of the guide surface that comes into contact with the tape.
It is publicly known from the publication No. 9-124072.

In addition, the magnetic surface and base film of tapes are generally mirror-finished to improve head touch and reduce amplitude modulation noise. In such tapes, it is also known to provide a bank coat layer containing carbon or the like on the back surface of the tape in order to prevent interlayer adhesion and sticking to the tape guide member.

[Problem to be solved by the invention]

When a back coat layer is provided on the tape, the surface roughness of the back surface of the tape becomes rough, and, for example, the coefficient of friction between the tapes is reduced, and adhesion between the tapes is reduced, thereby preventing interlayer adhesion.

However, with tape cartridges that guide the tape with a fixed tape guide member made of plastic,
Although tape sticking is eliminated, wear on the guide member side becomes a problem. In particular, in the Phillips-type tape cartridge in which the guide block described above is provided with a large number of guide ribs, the tape comes into contact with each guide rib at the same time, which significantly increases frictional resistance due to wear and increases frequency modulation noise.

The present invention has been proposed to solve the above problems.

The purpose of the present invention is to improve the material of the guide plotter, improve its abrasion resistance, reduce the coefficient of friction against the tape with a back coat layer, and reduce the increase in modulation noise caused by the wear of the guide ribs provided in the guide block. To obtain a tape cartridge with improved acoustic characteristics.

[Means to solve the problem]

The present invention is a tape cartridge that incorporates a separate guide block 7 for defining the tape path of a tape with a back coat layer 3 inside the front side of a main body case 1, in which the guide block 7 is molded from a phenolic resin containing glass fiber. This improves the wear resistance of the guide ribs 12 on the guide block 7 side relative to the tape 3, and at the same time reduces the coefficient of friction.

In addition, when the amount of glass fiber mixed in increases, the fluidity of the resin during molding deteriorates, and moldability is impaired.

Moreover, if the amount of mixing is insufficient, it becomes difficult to obtain sufficient wear resistance and friction reduction effects. Therefore, it is preferable to set the amount of glass fiber mixed within the range of 10 to 40% by weight.

Regarding the surface roughness of the back coat layer of the tape 3, if the center line average roughness (Ra) is 0.011 μm or more, a sufficient friction reduction effect can be obtained. Since there is a risk of wear, the center line average roughness (Ra) should be 0°011 to 0.014μ.
It is preferable to set it within the range of m. Furthermore, the back coat layer contains calcium carbonate, and after setting the above surface roughness, the guide ribs 12 of the guide block 7 and the tape 3 are coated.
It is desirable to set the friction coefficient between 0.3 and 0.4.

[Effect]

Phenol resin, which is a thermosetting resin, is inherently superior in mechanical properties, hardness, and dimensional stability compared to thermoplastic resins, such as polystyrene and polypropylene, which are conventional molding materials for guide blocks. Furthermore, the inclusion of glass fibers further improves the hardness and mechanical properties, resulting in a high degree of abrasion resistance, and the glass fibers reduce the coefficient of friction.

〔Example〕

1 and 2 illustrate a Phillips type tape cartridge as a specific example of the tape cartridge according to the present invention.

In FIG. 1, reference numeral 1 denotes a main body case, which is made up of upper and lower plastic cases 1a and 1b screwed together in a lid-to-bottom manner. A pair of left and right hubs 4, 4, which are provided in a penetrating manner and around which a tape 3 is wound inside the main body case 1, are positioned in each drive shaft insertion hole 2, 2'' and are rotatably arranged.

Guide rollers 5,5 are arranged on the left and right sides of the front end inside the main body case 1, and the tape 3 is wound from one hub 4, through the front of the case, to the other hub 4 via these guide rollers 5,5.

A separate guide block 7 that defines a tape bus for the tape 3 is installed inside the front side of the main body case 1 with a left and right length that extends approximately between both guide rollers 5 and 5, and is positioned between the upper and lower cases 1a and 1b. It is held in a fixed state.

In FIG. 2, the guide block 7 corresponds to a main face plate 8 that partitions the front part of the case into front and rear parts, a head insertion window 9, a pinch roller push-in window 10, and an erasing head insertion window 11 set on the front of the main body case l. A total of six guide ribs 12 are integrally formed to protrude from the front end of the main face plate 8. A head pad 3 is positioned and supported between both ribs 12 by using guide ribs 12 corresponding to the head insertion window 9, and a magnetic shielding plate 15 is placed between the protruding base ends of both ribs 12. is installed.

Tape 2 has a magnetic layer formed on the surface of a base film made of polyester resin, and a back coat layer containing calcium carbonate is coated on the back side. The surface roughness of the back coat layer is a center line average roughness (Ra) of 0.01
The thickness was adjusted to 1 to 0.014 μm. The thickness of the magnetic layer was 2 to 3 μm, the thickness of the base film was 8 to 10 μm, and the thickness of the bank coat layer was 0.5 μm.

The guide block 7 is based on phenolic resin,
This was injection molded using a composite plastic material mixed with 25% glass fiber by weight.

[Comparative example]

Based on polypropylene, 55% by weight
A guide pro 7 was molded from a plastic material mixed with calcium carbonate in the same manner as in the example.

A tape cartridge shown in FIG. 1 was made using each of the guide blocks 7 obtained above, and the coefficient of friction between the tape 3 and the guide ribs 12 on the left and right sides of the center facing the head insertion window 9 was measured for each cartridge. As a result, the friction coefficient of the present invention example was 0°35, and the friction coefficient of the comparative example was 0.4.
It was 3.

Next, wear tests and frequency modulation noise measurements were performed on each of the above tape cartridges.

(Abrasion test) Each tape cartridge was run back and forth in playback mode, and the wear amount of the central guide rib (2) was measured at regular intervals. At that time, the center line average roughness (Ra) of the back coat layer of the tape was measured. was adjusted to 0.023 μm to enable the effect of wear to be confirmed more clearly.As a result,
The guide rib 15 of the height measurement according to the present invention showed no wear even after running 100 times. On the other hand, the guide rib of the comparative example is
Abrasion of 4 μm was observed after 25 runs, and 8 μm of wear was observed after 75 runs. This confirmed that the examples of the present invention had sufficient wear resistance compared to the comparative examples.

(Measurement of modulation noise) The tape explained in the above example (center line average roughness (Ra)
(0.011 μm), the frequency modulation noise of the comparative example and the example of the present invention was measured. For details, see 10 K11.
After recording the z reference signal, the modulation noise contained in the reproduced output signal was measured. Figure 3 shows the results. The horizontal axis in FIG. 3 is frequency, and the vertical axis is output level (db).

As is clear from this characteristic diagram, it can be seen that the example of the present invention achieves a noise reduction effect of 2 to 5 dIl in most frequency bands compared to the comparative example.

In the same manner as above, 5 KHz% 12.5 Klf
z, 15Kllz, 18 old 1z, 20 K11
Modulation noise was measured for each standard (word) of z. The reduction level of modulation noise obtained by this measurement is shown in Figure 4. The horizontal axis in Figure 4 represents the reference signal frequency, and the vertical axis represents the comparison. It is a level reduction amount (db) of this invention Example with respect to an example.

As is clear from this characteristic diagram, the example of the present invention was able to reduce modulation noise in most of the audible range compared to the comparative example.

In addition to the above, the surface roughness of the back coat layer of the tape has a center line average roughness (Ra) of 0.006 μm, o, ot.

μm and 0.023 μm, respectively, and measured the frequency modulation noise of the comparative example and the example of the present invention when a reference signal of 10 Klfz was applied, but the center line average roughness (Ra) was 0. 006, ijm, 0.0
No noise reduction effect was obtained in either case of 1 μm or 1 μm. In addition, the center line average roughness (Ra) is 0°023
In the case of μm, the center line average roughness (Ra) is 0.011μ
The results were almost the same as in the case of m.

From the above measurement results, it was found that molding the guide block 7 with a phenolic resin reinforced with glass fibers can improve its wear resistance, and that the coefficient of friction between the guide ribs 12 and the tape 3 can be reduced with the glass fibers.

〔Effect of the invention〕

As explained above, in the present invention, the guide block 7 is molded from a phenolic resin containing glass fiber to improve its wear resistance, and the guide rib 1 is molded by mixing glass fiber.
Since the coefficient of friction between the tape 2 and the tape 3 is reduced, the guide rib 12 can be effectively prevented from being abraded by the bank coat layer of the tape 3 when the tape runs. Moreover, tape 3
It is also possible to sufficiently reduce the frictional resistance in the recording/playback state where the guide ribs 12 are pressed against the guide ribs 12. As a result, the running resistance of the tape 3 is reduced, the running state of the tape 3 is made smooth, and the occurrence of frequency modulation noise is suppressed, so that the acoustic characteristics can be improved.

[Brief explanation of drawings]

FIG. 1 is an internal plan view of a tape cartridge according to the present invention, and FIG. 2 is a perspective view of a guide block. FIG. 3 is a noise characteristic diagram showing the measurement results of modulation noise, and FIG. 4 is a level reduction characteristic diagram showing the degree of noise reduction for each reference signal. ■・・・Body case, 3・・・Tape, 7・・・Guide block, ・Guide rib. Inventor Akihiko Sato Osamu Yamamoto Guide Rib Diagram Diagram

Claims (1)

[Claims] 1. A tape cartridge in which a separate guide block (7) for defining the tape path of the back coat layered tape (3) is incorporated inside the front side of the main body case (1), comprising: A tape cartridge characterized in that (7) is molded from a phenolic resin containing glass fiber.