JP2503744Y2 - Magnetic head unit - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head unit, and more particularly to a magnetic head unit capable of preventing magnetic tape powder from falling off during running of a magnetic tape.

2. Description of the Related Art A magnetic head unit used in a cassette tape recorder, for example, guides the recording / reproducing or erasing process of a magnetic tape in sliding contact with a magnetic head to guide the running of the magnetic tape and keep the sliding contact condition with the magnetic head constant. It is composed of a tape guide having a function of keeping.

An example of a conventional magnetic head unit is shown in FIG. In the figure, 1 is a magnetic head, and 2 and 3 are tape guides. The tape guides 2 and 3 are, for example, 66-nylon integrally molded with a resin containing 20% carbon fiber, and the positioning surfaces 2a and 3a and the pushing surfaces 2b and 3b.
Is formed. The push-up surfaces 2b and 3b are slanted surfaces, and the magnetic tape (not shown) is urged upward by the push-up surfaces 2b and 3b at the lower edge thereof during running, and the upper edge is positioned at the positioning surface 2a. The traveling position is positioned by being slidably contacted with 3 and 3a.

Problems to be Solved by the Invention However, it is empirically known that, in the above-described conventional magnetic head unit, when the magnetic tape is run, the magnetic tape powder falls off. The tape magnetic powder that has fallen off adheres to the magnetic head 1 and adversely affects the recording / reproducing or erasing process. Specifically, it causes deterioration of the high range, sound skipping, and wow and flutter.

The present invention has been made in view of the above points, and provides a magnetic head unit with improved recording / reproducing characteristics and the like by configuring a tape guide to prevent generation of magnetic tape powder. With the goal.

Means and Actions for Solving Problems In order to solve the above problems, in the present invention, a magnetic head for recording / reproducing or erasing a magnetic tape and a side edge of the magnetic tape are slidable. A tape guide provided with a positioning surface that is in contact with the magnetic tape and positions the running position of the magnetic tape, and an inclined push-up surface that slidably contacts the other side edge of the magnetic tape to bias the magnetic tape toward the positioning surface. In the magnetic head unit configured by, at least the pushing-up surface of the tape guide is formed by a pin-shaped member having a smooth surface and a curved surface.

By configuring the magnetic head unit as described above, the dynamic friction coefficient between the magnetic tape and the tape guide can be reduced, the running of the magnetic tape becomes smooth, and the generation of magnetic tape powder can be suppressed.

Further, the push-up surface is formed by a pin-shaped member having a smooth surface and a curved surface, and the pin-shaped member is easy to form and can be manufactured at low cost, so that the cost of the magnetic head unit can be reduced. Can be realized.

Embodiment Next, a first embodiment of the magnetic head unit according to the present invention will be described with reference to FIG. The magnetic head unit 4 shown in the figure comprises a magnetic head 5, tape guides 6 and 7, and guide pins 8 and 9.

The magnetic head 5 is a reverse-compatible recording / reproducing head. Tape guides 6 and 7 are adhesively fixed to both sides of a magnetic tape 10 (shown by a chain line in the drawing) of the magnetic head 5 in the running direction. Further, when the tape guides 6 and 7 are bonded, the guide pins 8 and 9 which are essential parts of the present invention are interposed between the magnetic head 5 and the tape guides 6 and 7, and are attached and fixed together.

The tape guides 6, 7 are formed by integrally molding a resin containing 20% of carbon fiber in 66-nylon as in the conventional case, and the flange portions 6a, 7 are formed on the upper portion facing the magnetic tape 10.
Form a. The portions of the collar portions 6a and 7a that are in sliding contact with the magnetic tape 10 are formed into a curved surface, and the positioning surfaces 6a- ₁ and 7a-
_Make up ₁ .

The positioning surfaces 6a- ₁ and 7a- ₁ are positioned with high accuracy at the upper edge position of the magnetic tape 10 at the default running position. Therefore, the upper edge 10a of the magnetic tape 10 is aligned with the positioning surface 6a-
_The magnetic tape can be run by sliding it against ₁ , 7a- ₁ .
10 travels while being positioned at a predetermined traveling position.

The guide pins 8 and 9 are pin-shaped members made of a hard metal (for example, stainless steel) which is a non-magnetic material or a soft magnetic material, or a ceramic, and as shown in FIG. In this state (hereinafter, this inclination angle is referred to as a push-up angle θ), the magnetic head 5 and the tape guides 6 and 7 are adhesively fixed. The guide pins 8 and 9 have a circular cross section, and their surfaces are smooth. That is,
The friction coefficient on the surface of the guide pins 8 and 9 is configured to be extremely small. As described above, the guide pins 8 and 9 are pin-shaped members, and a technique of forming a non-magnetic material, a soft magnetic material or a ceramic into a pin shape, and a technique of processing the surface of the pin-shaped member into a smooth surface have also been established. Therefore, the guide pins 8 and 9 having a smooth surface can be easily manufactured at low cost.

The magnetic tape 10 runs while its lower edge 10b is in sliding contact with the guide pins 8 and 9. As described above, since the guide pins 8 and 9 are provided with the push-up angle θ, they function as push-up surfaces, and the magnetic tape 10 is biased upward during traveling. Further, as is well known, the magnetic tape 10 runs while being slightly curled at the sliding contact position with the guide pins 8 and 9. As a result, the upper edge 10a of the magnetic tape 10 is pressed against the positioning surfaces 6a- ₁ and 7a- ₁ , and the magnetic tape 10 is run at the predetermined running position.

Here, an experiment conducted by the present inventor for investigating the dropout of the tape magnetic powder in the magnetic head unit 4 having the above configuration will be described below. First, for comparison, FIGS. 2 (A) and 2 (B) show the falling state of the tape magnetic powder in the conventional magnetic head unit (shown in FIG. 6). The experimental conditions are as follows. In addition, in the following conditions, the separation dimension L
Is the distance between the position where the magnetic tape contacts the positioning surface and the position where the magnetic tape contacts the lifting surface.

○ Magnetic tape running time (H) ・ ・ ・ ・ ・ ・ 72 hours ○ Push-up angle (θ) ・ ・ ・ ・ ・ ・ 60 ° ○ Spacing dimension (L) ・ ・ ・ ・ ・ ・ 3.7mm Fig. 2 ( A) and (B) show the results obtained by preparing two magnetic head units having the same structure and performing an experiment for each under the above conditions. As shown in the figure, a large amount of magnetic tape powder (indicated by a satin-like magnetic powder in the figure) has fallen off from the magnetic tape, and adheres to the sliding contact surface 1a of the magnetic head 1. In particular, a large amount of magnetic tape powder adheres at the upper and lower positions of the sliding contact surface, and it can be seen that a large amount adheres to the lower part when comparing the upper part and the lower part. It is considered that this is because the tape magnetic powder is generated at the sliding contact position between the magnetic tape and the tape guides 2 and 3.

In the state where the tape magnetic powder is removed as shown in the figure, in order to maintain the normal recording / reproducing characteristics of the magnetic head 1, it is necessary to frequently perform head cleaning, and if the head cleaning is neglected, Characteristic deterioration will occur in a short period of time.

On the other hand, FIG. 3 (A) and FIG. 3 (B) show the falling state of the tape magnetic powder by the magnetic head unit 4 according to the present invention.
The experimental conditions are as follows.

○ Running time of magnetic tape (H) ・ ・ ・ ・ ・ ・ 85 hours ○ Push-up angle (θ) ・ ・ ・ ・ ・ ・ 30 ° ○ Separation dimension (L) ・ ・ ・ ・ ・ ・ 3.5mm ○ Guide pin Material ························································································································································································. I am only doing it. When the tape magnetic powder falls off to such an extent, this does not have to be a particular problem, and the magnetic head 5 can maintain normal recording / reproducing characteristics for a long period of time. Moreover, the number of times of head cleaning can be significantly reduced.

It is considered that the tape magnetic powder is prevented from falling off in the magnetic head unit 4 having the configuration of the present application for the following reason. As described above, the guide pins 8 and 9 are made of a hard metal such as stainless steel, and their surfaces are smooth and have a curved shape (specifically, a circular cross section).

Therefore, the dynamic friction coefficient of the surface of the guide pins 8 and 9, that is, the surface in sliding contact with the magnetic tape 10 has a small value, and the sliding contact area between the magnetic tape 10 and the guide pins 8 and 9 is small. ing. Therefore, the magnetic tape 10 at the sliding contact position
The peeling of the magnetic material coated on the tape is suppressed, and the tape magnetic powder is prevented from falling off.

Further, even though the positioning surfaces 6a- ₁ and 7a- ₁ have the same structure as the conventional _one , the tape magnetic powder is prevented from falling off because the surfaces of the guide pins 8 and 9 are smooth surfaces. When the tape 10 is pushed up by the guide pins 8 and 9 while running, the tape 10 makes a smooth upward movement, and the magnetic tape 10 is positioned on the positioning surfaces 6a- ₁ and 7a- _1.
It is thought to be due to the fact that it will not collide strongly with.

As described above, even in the magnetic head 4 according to the present invention, a small amount of tape magnetic powder adheres to the position below the sliding contact surface 5a. This is probably due to the following reasons. That is, generally, the coefficient of dynamic friction between the magnetic tape 10 and the guide pins 8 and 9 on the push-up surface (that is, the position where the guide pins 8 and 9 are in sliding contact with the magnetic tape 10) is the magnetic tape 10 and the positioning surface 6a- _1. , 7a- ₁ is greater than the dynamic friction coefficient. Therefore, even if the dynamic friction coefficient and the sliding contact area at the sliding contact position between the magnetic tape 10 and the guide pins 8 and 9 are reduced by the configuration of the present invention as described above, the generation of magnetic powder is completely prevented. However, it is considered that the magnetic powder remains on the surface in the vicinity of the pin-shaped members 8 and 9 because the magnetic powder remains. However, as described above, the adhesion of the magnetic powder to this extent does not cause any inconvenience in the magnetic recording / reproducing process.

On the other hand, in the conventional magnetic head unit, since the tape guides 2 and 3 (shown in FIG. 6) are simply formed by molding, the push-up surfaces 2b and 3b have a large surface roughness and a dynamic friction. The coefficient was also large. Therefore, it is considered that a large amount of tape magnetic powder was generated as shown in FIG.

The second embodiment of the magnetic head unit according to the present invention is the fourth embodiment.
FIG. 5A and FIG. 5B show the falling state of the magnetic tape powder in the magnetic head unit 11 shown in FIG. The same components as those of the magnetic head unit 4 shown in FIG. 1 are designated by the same reference numerals and the description thereof is omitted.

The magnetic head unit 11 shown in FIG. 4 has a positioning pin 12, made of the same material as the guide pins 8, 9 instead of the flange portions 6a, 7a formed on the tape guides 6, 7 shown in the first embodiment. 13
Is provided, and a tape guide is constituted by the guide pins 8 and 9 and the positioning pins 12 and 13. The guide pins 8 and 9 and the positioning pins 12 and 13 are adhesively fixed to the side portions of the magnetic head 5 together with the holders 14 and 15. At this time, the positioning pins 12 and 13 are positioned with high accuracy at the upper edge position of the magnetic tape 10 at the predetermined running position, like the positioning surfaces 6a- ₁ and 7a- ₁ described above.

In the magnetic head unit 11 having this structure, the tape magnetic powder is further prevented from falling off as shown in FIGS. 5 (A) and 5 (B), and in FIG. There is. By providing the positioning pins 12 and 13, the tape magnetic powder is further prevented from falling off. However, compared with FIGS. 2 and 3, the tape magnetic powder is prevented from falling off.
It can be seen that the part that is the push-up surface has a great influence.
The experimental conditions for the experimental results shown in FIG. 5 were the same as those shown in FIG.

In the above experimental results, there is a difference in the push-up angle θ and the separation dimension L between the conventional configuration and the configuration of the present application. This is because the positioning surfaces 6a- ₁ , 7a- ₁ , 16a, 17 of the magnetic tape 10 are different.
This is to adjust the pressing force against a constant, and does not affect the generation of magnetic tape powder.

Effect of the Invention As described above, according to the magnetic head unit of the present invention, the push-up surface is formed by the pin-shaped member having a smooth surface and a curved surface, so that the dynamic friction coefficient on the push-up surface becomes small. The fall of the magnetic powder is prevented, and thus the fallen tape magnetic powder does not adhere to the sliding contact surface of the magnetic head, which can prevent the deterioration of the recording / reproducing or erasing characteristics of the magnetic head and damage the magnetic tape. Since the pin-shaped member can be easily formed and can be manufactured at low cost, the magnetic head unit can be manufactured at low cost.

[Brief description of drawings]

FIG. 1 is a perspective view of a first embodiment of a magnetic head unit according to the present invention, FIG. 2 is a view for explaining a falling state of tape magnetic powder in a conventional magnetic head unit, and FIG. 3 is FIG. FIG. 4 is a diagram for explaining a state in which magnetic tape powder has fallen off in the magnetic head unit shown in FIG. 4, FIG. 4 is a perspective view of a second embodiment of the magnetic head unit according to the present invention, and FIG. 5 is a magnetic head shown in FIG. FIG. 6 is a diagram for explaining the falling state of magnetic tape powder in the unit, and FIG. 6 is a perspective view of an example of a conventional magnetic head unit. 4,11 ... Magnetic head unit, 5 ... Magnetic head, 6,7
…… Tape guide, 6a- ₁ , 7a- ₁ …… Positioning surface, 8,9 ……
Guide pin, 10 …… Magnetic tape, 12,13 …… Positioning pin.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Kazuhito Kurita, 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation (56) References JP-A-58-17514 (JP, A) JP-A-61- 220104 (JP, A) Actual development Sho 56-149323 (JP, U) Actual public Sho 49-31859 (JP, Y1)

Claims (1)

(57) [Scope of utility model registration request] 1. A magnetic head for recording / reproducing or erasing when a magnetic tape is slidably contacted, a positioning surface for slidably contacting one side edge of the magnetic tape for positioning the running position of the magnetic tape, and the magnetic tape. And a tape guide provided with an inclined push-up surface for urging the magnetic tape toward the positioning surface, the other side edge of which is slidably contacted, and at least the push-up of the tape guide is performed. A magnetic head unit having a structure in which the surface is formed by a pin-shaped member having a smooth surface and a curved surface.