JP2899058B2 - Magnetic head - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head, and more particularly, to a magnetic head which performs magnetic recording or reproduction of information by sliding relative to a magnetic tape pressed by a pad. Things.

2. Description of the Related Art In a cassette tape recorder or the like, magnetic recording or reproduction of an audio signal or the like is performed by relative sliding of a magnetic tape and a magnetic head. Further, a pad for pressing the magnetic tape against the magnetic head is provided on the tape cassette side in order to maintain uniformity.

This pad improves the contact between the magnetic tape and the magnetic head.However, the pressure of this pad increases the sliding torque during tape running, causing wow and flutter that makes the tape speed unstable and the magnetic tape sliding surface. There was a point that it increased the abrasion.

In order to eliminate this drawback, the present applicant provides a ridge on the sliding surface of the magnetic tape of the magnetic head, which comes into contact with both ends of the pad protruding from both side edges of the magnetic tape and reduces the pressing force of the pad against the magnetic tape. A proposal was made.
-91809).

FIG. 3 shows a conventional magnetic head for a cassette tape recorder employing such a structure.

As shown in FIG.
In this case, a four-channel magnetic core 4 faces the center of the. A magnetic tape 5 is pressed against the magnetic head sliding surface 3 by a pad 6 shown by a broken line, slides in a direction shown by an arrow a, and slides on the magnetic core 4 to perform recording or reproduction. .

The above-mentioned ridges 8 are formed in a strip shape on each side edge of the magnetic tape sliding surface 3 along the magnetic tape sliding direction a. Further, since both ends of the pad 6 protruding from both side edges of the magnetic tape 5 are pressed against the respective protruding central portions more strongly, the pressing force of the pad 6 against the magnetic tape 5 is reduced by that much, and the above-mentioned disadvantage is solved. Will be resolved.

[Problems to be Solved by the Invention] In the case of the magnetic head shown in FIG. 3, the ridge 8 formed on the magnetic head sliding surface 3 is easy to form accurately and easily. Metal by a physical method through a mask with a window, or by using a screen with a ridge-shaped window, transferring liquid resin by screen printing, etc., and adhering and curing the resin. Is being done.

However, in the ridge formed as described above, since the entire ridge receives a thermal change at the time of film formation, a force may be exerted to peel off the sliding surface 3 due to the contraction force of the ridge itself. . Therefore, a part of the ridge may be peeled off from the sliding surface 3 due to a change in temperature or humidity over time, or the whole may be lost, which may cause a great deterioration of a sliding torque and a wow and flutter during tape running. There was a problem that there is.

[Means for Solving the Problems] In order to solve the above problems, according to the present invention, it is possible to magnetically record or reproduce information by sliding relative to a magnetic tape pressed against a pad, A magnetic head formed on the sliding surface of the magnetic head by screen printing, wherein the protrusion contacts the portion of the pad protruding from both sides of the magnetic tape to reduce the pressure contact force of the pad, wherein the protrusion includes a plurality of protrusions. A configuration is employed in which the projections are independently formed directly on the sliding surface.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG.

FIG. 1 is a perspective view showing the structure of a magnetic head for a cassette tape recorder as this embodiment.

As shown in FIG. 1, in the center of the magnetic tape sliding surface 3 of the magnetic head 1, a magnetic core 4 of four channels in this case is provided.
Are exposed with a gap G. The magnetic tape 5 is pressed against the magnetic tape sliding surface 3 by a pad at a position 6 indicated by a broken line, and slides in a direction indicated by an arrow a to perform recording or reproduction.

On the sliding surface 3 of the magnetic tape, projection groups 7, 7 'are provided at both side edges along the sliding direction of the magnetic tape, a part of which is in contact with the pad.

Hereinafter, with respect to a specific manufacturing method and the operation and effect of the present embodiment, a method of forming a projection group using screen printing will be described.

As a screen plate used in the embodiment of the present invention, a stencil for preventing liquid resin from being transmitted was formed on a 200-mesh screen having a thickness of 30 μm.
A perforated pair of plate images corresponding to the group of projections corresponding to the figure, and, as a conventional example, a pair of plates corresponding to the ridges corresponding to FIG. A screen plate with perforated images was prepared.

As a liquid resin used for screen printing, UVX-507 (manufactured by ThreeBond), which is an ultraviolet-curing resin, is applied to both sides of the sliding surface of the 4-channel magnetic head along the magnetic tape sliding direction using the above two types of screen plates. The ultraviolet-curable resin is transferred from the plate image, and then irradiated with ultraviolet light having a wavelength of 365 nm and an illuminance of 200 mW / cm ² for 30 seconds. The projections shown in FIG. 1 according to the present embodiment and FIG. Ten magnetic heads each having a ridge were prepared. In order to check the adhesion between the magnetic head sliding surface and the ultraviolet curable resin for these magnetic heads, a thermal cycle test was repeated 200 times at −40 ° C. for 30 minutes and at 80 ° C. for 30 minutes. When the bonding state of the ultraviolet curing resin was compared, no peeling of the projection group was found in the present example, whereas in the conventional example, 6 pieces that partially peeled were Two missing pieces were found.

FIG. 2 is a plan view showing the structure of a sliding surface of a magnetic recording medium of a magnetic head according to another embodiment of the present invention. In FIG. 2, the same components as those in FIG. In this embodiment, elliptical projection groups 7a and 7a 'whose longitudinal direction is the direction perpendicular to the sliding surface of the magnetic recording medium are provided, and a part of each projection comes into contact with the pad. Incidentally, the contact position of the pad is the portion within the broken line in FIG.

It is apparent that the magnetic head shown in FIG. 2 has the same effect as the magnetic head shown in FIG.

The shape of the projection group is not limited to the shapes shown in FIGS. 1 and 2, and even if the shape in the group is different, or the height of the projection in the group from the sliding surface of the magnetic head is different. Has the same effect.

[Effects of the Invention] According to the configuration of the present invention, since a plurality of protrusions are formed directly on the sliding surface of the magnetic head independently of each other, the generated contraction force is small, and the protrusion from the sliding surface is small. Peeling can be prevented.

[Brief description of the drawings]

FIG. 1 is a perspective view of a magnetic head embodying the present invention, FIG. 2 is a plan view showing a tape sliding surface of a magnetic head showing another embodiment of the present invention, and FIG. It is a perspective view of a magnetic head showing an example. 3 is a magnetic head sliding surface 4 is a magnetic core 5 is a magnetic tape 6 is a pad pressure contact position 7, 7 ', 7a, 7a' is a projection group 8 is a ridge a is a magnetic tape sliding direction G is a magnetic gap .

Claims (1)

(57) [Claims] An information recording / reproducing method is possible by sliding relative to a magnetic tape pressed against a pad, and a portion of the pad protruding from both side edges of the magnetic tape is contacted to reduce a pressing force of the pad. A magnetic head in which the number of protrusions to be reduced is formed on a sliding surface of the magnetic head by screen printing, wherein the plurality of protrusions are formed directly on the sliding surface independently of each other. Magnetic head.