JPH0450561Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic head, and more particularly to a magnetic head in which a sliding surface is formed facing a magnetic tape that is pressed against a pad.

[Prior Art] FIG. 7 shows the structure of a four-channel, auto-reverse head for audio as a conventional structure of this type of magnetic head.

In FIG. 7, reference numeral 1 denotes a shield case that houses and supports the components of the head. Inside this shield case 1, four magnetic cores 2 corresponding to each of the four channels are wound with coils (not shown) and mutually connected. The magnetic shield plates 3 and 3' are inserted between them, and fixed by a fixing member 4 made of resin filled in the shield case 1. The tip end surface of each magnetic core 2 provided with a magnetic gap G is exposed through an opening 1a formed in the upper surface of the shield case 1 in the figure. The upper surface of the shield case 1, the top surfaces of the magnetic core 2 and the magnetic shield plates 3 and 3' exposed in the opening 1a, and the surface of the fixing member 4 are attached to a magnetic tape slider, which is slid on a magnetic tape (not shown). It constitutes a moving surface (hereinafter abbreviated as sliding surface) 5.

A pair of tape guides 6, 6 are provided at both ends of the tape entry side and tape exit side of the sliding surface 5 to regulate the running position of the magnetic tape and to make the magnetic tape run on a predetermined track on the sliding surface 5. They are provided facing each other and fixed to the side surface of the shield case 1.

In a magnetic head having such a structure, a magnetic tape (not shown) is pressed against the central part of the sliding surface 5, that is, the region of the magnetic core 2, by a pad (not shown).
The tape slides and is regulated by tape guides 6, 6, and recording and playback are performed.

[Problems to be Solved by the Invention] By the way, the reason why the magnetic tape is pressed against the sliding surface 5 of the magnetic head by the pad is to suppress the occurrence of so-called spacing loss.

However, when such pressure contact is performed, there is a problem that the sliding torque required to slide the magnetic tape increases and the sliding surface 5 wears out more quickly due to sliding.

Furthermore, in the structure shown in FIG. 7, the running position of the magnetic tape is regulated at both ends of the sliding surface 5, and not in the area of the magnetic core 2 in the center.
Problems such as deterioration of electromagnetic conversion characteristics and occurrence of crosstalk have occurred due to track deviation.

[Means for Solving the Problems] In order to solve these problems, according to the present invention, a sliding surface is formed opposite to the magnetic tape pressed by a pad, and the outer side of the sliding surface is In a magnetic head that is provided with protrusions that contact both ends of the pad, the protrusions reduce the pressing force of the pad against the magnetic tape, and the protrusion height increases as the pad contact surface of the protrusions approaches the sliding surface. The structure is slanted so that the height is lower.

[Function] According to such a structure, the sliding torque of the magnetic tape can be reduced by reducing the pressing force of the pad by the above-mentioned protrusions, and the wear of the sliding surface of the magnetic tape can also be suppressed. In addition, since the contact surface of the protrusion with the pad is formed on the above-mentioned slope, the edge of the protrusion on the tape sliding area side can be pressed against the pad over the entire width of the magnetic tape to suppress spacing loss. Even if the height of the protrusion from the magnetic tape sliding surface is reduced, a sufficient effect of reducing the pad pressing force can be obtained. In addition, by lowering the height of the edge, the protrusions can be placed very close to both edges of the magnetic tape, and the protrusions can regulate the running position of the magnetic tape in the width direction on the sliding surface. Can be configured.

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 1 shows an embodiment of the present invention, which has four channels for audio, similar to the conventional head shown in Figure 7.
This shows the structure of an auto-reversing head. In FIG. 1, the parts common to those in the conventional example shown in FIG. 7 are given the same reference numerals, and the explanation thereof will be omitted, and the parts different from the conventional example will be explained below.

As shown in FIG. 1, the magnetic head of this embodiment has the same structure as the conventional head shown in FIG.
Protrusions exemplified as protrusions 7, 7 are provided on the magnetic tape sliding surface (hereinafter also abbreviated as sliding surface) 5, that is, on the upper surface of the shield case 1. For details, protrusion 7,
7 is an opening 1a in which the magnetic core 2 of the sliding surface 5 is exposed.
It is provided so as to sandwich the magnetic tape sliding area of the sliding surface 5, and the sliding surface 5 is provided so as to sandwich the magnetic tape sliding area of the sliding surface 5. When viewed from above in the figure, the sliding surface 5 has a substantially rectangular shape along both side edges parallel to the magnetic tape sliding direction. It is formed to extend over almost the entire length of the moving surface 5.

Further, the protrusions 7, 7 are formed so that the width at the center adjacent to the opening 1a is wider than at both ends. and,
The cross-sectional shape of the center portion of the protrusions 7, 7 along line A-A' in FIG. 1 is approximately wedge-shaped, as shown in FIGS. Most of the area except for a predetermined width on the outside is an inclined surface 7 which is inclined so that the height of the protrusion from the sliding surface 5 decreases as it approaches the sliding area of the magnetic tape 8 shown in FIG.
It is formed in a.

Based on this structure, during recording and reproduction in the head of this embodiment, the magnetic tape 8 is pressed against the sliding surface 5 by the elastic pad 9, as shown in FIG. The original shape of Pad 9 is a rectangular parallelepiped,
Both end portions of the magnetic tape 8 protruding from both side edges come into contact with the inclined surfaces 7a of the protrusions 7, 7, are relatively pressed and deformed, and the central portion comes into pressure contact with the magnetic tape 8.

In this case, the inclined surface 7a presses the pad 9 relatively, so that the pressing force of the pad 9 against the magnetic tape is reduced, the sliding torque of the magnetic tape 8 mentioned above can be reduced, and the wear of the sliding surface 5 is reduced. can be held down.

Here, FIG. 4 shows the relationship between the height of the protrusion of the inclined surface 7a from the sliding surface 5 and the corresponding sliding torque of the magnetic tape. Specifically, as shown in FIG. 3, the height of the top surface 7c of the protrusion 7 from the sliding surface 5 is constant at 0.55 mm, and the edge 7b of the inclined surface 7a on the magnetic tape sliding area side is The graph shows the results of measuring the sliding torque T corresponding to each height h while changing the height h from the sliding surface 5 within a range of 0 to 0.1 mm.

As shown in FIG. 4, the effect of reducing the sliding torque appears when the height h of the edge 7b is about 0.01 mm, such that the sliding torque T = 53, and below h = 0.05 mm.
It can be seen that the greater the height h, the greater the effect of reducing the sliding torque T, such as T=28, h=0.1 mm, and T=20.

However, if the height h is made larger than 0.1 mm, the deformation of the pad 9 will be insufficient, and the pad 9 will not be able to press against both side edges of the magnetic tape 8 near the protrusions 7, 7, resulting in a spacing loss in this area. This causes the electromagnetic conversion characteristics to deteriorate and the running of the magnetic tape 8 to become unstable.

Therefore, in order to appropriately reduce the pressure contact force of the pad 9 and to enable the pad 9 to contact the entire width of the magnetic tape 8 in order to suppress spacing loss, the height h should be within the range of 0.01 to 0.1 mm. Preferably it is within the range of 0.05 to 0.1 mm.

In this way, according to this embodiment, the sliding torque T of the magnetic tape 8 can be reduced, the wear of the sliding surface 5 can be suppressed, and the loss of the spacing 7 can be suppressed, resulting in good electromagnetic conversion. characteristics are obtained.

Moreover, the protrusion 7 having the inclined surface 7a of this embodiment,
7 is formed flat, assuming that the height h of the edge 7b on the magnetic tape sliding area side is the same.
The pressure force of the pad 9 on the magnetic tape 8 is reduced to the inclined surface 7a.
A greater reduction can be achieved through the slope of .

That is, even if the height h of the edge 7b of the protrusion 7 is reduced so that the pad 9 can be pressed against the magnetic tape 8 over the entire width with the necessary pressure contact force as described above, the pad 9 can be pressed against the magnetic tape 8 through the slope of the slope 7a. The effect of reducing the pad pressing force can be sufficiently obtained.

In addition, since the height h of the edge 7b can be reduced in this way, as shown in FIG.
The edge 7b of the magnetic tape 8 can be positioned on the sliding surface 5 very close to both side edges of the magnetic tape 8. That is, the distance between the edges 7b, 7b of the protrusions 7, 7 is made equal to the guide width of the tape guide 6 (3.82±0.05 mm ₀ in the case of a cassette tape), and the protrusions 7, 7 are arranged so that the distance between the edges 7b, 7b of the protrusions 7, 7 is equal to the guide width of the tape guide 6 (3.82± ^0.05 mm 0 in the case of a cassette tape). It can be configured such that the running position of the magnetic tape 9 in the width direction is regulated by the width direction.

With this configuration, the widthwise running position of the magnetic tape 8 can be regulated in the area of the magnetic core 2 at the center of the sliding surface 5, which was not regulated in the past, and the widthwise running position can be surely prevented. Therefore, problems such as deterioration of electromagnetic conversion characteristics, crosstalk, and damage to the magnetic tape 8 due to the positional shift can be avoided.

In the structure of this embodiment, the inclined surface 7a of the protrusion 7 is formed not as an inclined plane as shown in FIGS. 2 and 3, but as a curved surface curved in an arc shape, for example. You may.

Furthermore, the shape of the protrusions 7, 7 when viewed from above in FIG. 1 is of course not limited to that shown in FIG. The shape can also be considered.

In the example shown in FIG. 5, the protrusions 7, 7 have a substantially isosceles triangular shape when viewed from above, with the width at the center adjacent to the magnetic core 2 being the widest.

Further, in the example shown in FIG. 6, edges 7b, 7b are formed inside the protrusions 7, 7 in a curved arc shape.

Even with such a shape, the same effect can be obtained if the pad contact surface that contacts the pad 9 on the upper surface of the protrusions 7, 7 is formed into an inclined surface similar to the inclined surface 7a of the embodiment shown in FIG.

Note that these protrusions 7, 7 are connected to the tape guide 6,
It may be configured integrally with 6.

Furthermore, the structure in which the protrusions 7, 7 are provided as described above can be applied not only to the head of the embodiment, but also to all magnetic heads that perform recording and reproduction by sliding relative to a magnetic tape that is pressed into contact with a pad. Similar effects can be expected.

[Effects of the invention] As is clear from the above description, according to the invention, a sliding surface is formed facing the magnetic tape pressed by the pad, and both ends of the pad are formed on the outside of the sliding surface. In a magnetic head provided with a protrusion that contacts the magnetic tape, the protrusion reduces the pressing force of the pad against the magnetic tape, and the height of the protrusion decreases as the pad contact surface of the protrusion approaches the sliding surface. Since the inclined structure is adopted, the sliding torque of the magnetic tape and the wear of the sliding surface can be reduced by reducing the pad pressing force. In addition, by appropriately setting the height of the protrusion from the sliding surface of the inclined surface that contacts the pad of the protrusion, it is possible to press the pad over the entire width of the magnetic tape and prevent spacing loss. It can also be configured to regulate the running position of the magnetic tape in the width direction, and an excellent effect of obtaining good electromagnetic conversion characteristics can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing the structure of a magnetic head according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line A-A' when the pad is pressed into contact with the magnetic head, and FIG. Explanatory diagram of the cross-sectional shape of the protrusion in the figure, No. 4
The figure is a diagram showing the relationship between the height h of the edge of the protrusion in Figure 3 and the sliding torque T of the magnetic tape, and Figures 5 and 6 are top views of magnetic heads according to other different embodiments. 7 are perspective views showing the structure of a conventional magnetic head. 1... Shield case, 2... Magnetic core, 3,
3'...Magnetic shield plate, 4...Fixing material, 5...
Magnetic tape sliding surface, 6... Tape guide, 7...
Projection, 7a... Inclined surface, 8... Magnetic tape, 9...
...Putsudo.

Claims (1)

[Claims for Utility Model Registration] 1) In a magnetic head that has a sliding surface facing a magnetic tape that is pressed against a pad, and has protrusions on the outside of the sliding surface that contact both ends of the pad. , a magnetic head characterized in that the protrusion reduces the pressing force of the pad against the magnetic tape, and the contact surface of the protrusion with the pad is inclined so that the height of the protrusion decreases as it approaches the sliding surface. . 2) The magnetic head according to claim 1, wherein the height of the protrusion of the pad contacting surface of the protrusion is set so that the pad can press against the entire width of the magnetic tape. 3) The magnetic head according to claim 1 or 2, wherein the protrusion is configured to restrict the running position of the magnetic tape on the sliding surface in the width direction.