JPH046656A - Magnetic head - Google Patents

Abstract

PURPOSE:To prevent excess deterioration in a slide torque or wow and flutter from being incurred at tape running by providing a projection group in contact with a part of a pad protruded from both side edges of a magnetic tape so as to reduce a press contact force of the pad to a magnetic head slide face. CONSTITUTION:A position 6 shown by broken lines of a magnetic tape 5 is in press contact with a pad onto a magnetic tape slide face 3 in the middle of the magnetic tape slide face 3 of a magnetic head 1 and recording or reproduction is implemented by bringing the tape in slide contact in the direction as shown by the arrow (a). Then projection groups 7,7' whose part is in press contact with the pad are to each of both edges along the magnetic tape slide direction in the magnetic tape slide face 3. Thus, no adverse effect is exerted on a slide torque or wow and flutter at the tape running and the magnetic tape is driven stably.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic head, and particularly to a magnetic head that slides relative to a magnetic tape that is pressed against a pad to magnetically record information.
This invention relates to a magnetic head that performs reproduction.

[Prior Art] In cassette tape recorders and the like, audio signals, etc. are magnetically recorded or reproduced by sliding the magnetic tape and the magnetic head relative to each other. In order to maintain good and uniform contact, a pad is provided on the tape cassette side to press the magnetic tape against the magnetic head.

Although this pad improves the contact between the magnetic tape and the magnetic head, the pressure of this pad increases the sliding torque when the tape is running, causing wow and flutter that makes the tape speed unstable and the magnetic tape sliding. The problem was that it increased the wear on the surface.

In order to eliminate this drawback, the applicant provided a protrusion on the magnetic tape sliding surface of the magnetic head that contacts both ends of the pad protruding from both side edges of the magnetic tape and reduces the pressure force of the pad against the magnetic tape. A proposal was made (1986)
-91809).

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

As shown in the figure, in this case, a four-channel magnetic core 4 faces the center of the magnetic tape sliding surface 3 of the magnetic head 2. A magnetic tape 5 is pressed against this magnetic head sliding surface 3 by a pad 6 shown by a broken line, slides in the direction shown by arrow a, and is recorded or reproduced by sliding against the magnetic core 4. .

On the magnetic tape sliding surface 3, the above-mentioned protrusions 8 are formed in a band shape on each of both side edges along the magnetic tape sliding direction a. Since both ends of the pad 6 protruding from both side edges of the magnetic tape 5 come into stronger pressure contact with the central portions of the protrusions, the pressure force of the pad 6 against the magnetic tape 5 is reduced accordingly, and the above-mentioned drawbacks are avoided. It will be resolved.

[Problems to be Solved by the Invention] In the case of the magnetic head shown in FIG. 2, the protrusion 8 formed on the magnetic head sliding surface 3 has a protrusion shape because it is easy to form with high accuracy. Construct metal etc. by a physical method through a mask with windows, or by transferring liquid resin by screen printing etc. using a screen with protruding windows, and then attaching and curing the resin. is being done.

However, the entire ridge formed in this way is
Since the film undergoes thermal changes during film formation, a peeling force may be exerted on the sliding surface 3 due to the shrinkage force of the protrusion itself. Therefore, due to temperature changes, humidity changes, etc. over time, the sliding surface 3
There is a problem in that if a part of the protrusion comes off or the entire protrusion is missing, it may cause a large deterioration of sliding torque and wow and flutter during tape running.

[Means for Solving the Problems] In order to solve the above problems, the present invention provides a magnetic head that magnetically records or reproduces information by sliding relative to a magnetic tape that is pressed into contact with a pad. In this invention, a structure is adopted in which a group of protrusions are provided on the magnetic tape sliding surface to reduce the pressing force of the pad by contacting the portions of the pad protruding from both side edges of the magnetic tape.

[Function] This structure prevents the film from peeling off from the head surface due to shrinkage stress during film formation, and since it forms a group of protrusions, even if a few parts are missing over time. Also, there is no adverse effect on sliding torque or wow and flutter during tape running.

[Example 1] Hereinafter, details of an example of the present invention will be explained using FIG. 1.

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, a four-channel magnetic core 4 is exposed at the center of the magnetic tape sliding surface 3 of the magnetic head 1 with a gap G therebetween. A 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 is slid in the direction indicated by an arrow a, thereby performing recording or reproduction.

On the magnetic tape sliding surface 3, a group of protrusions 7.7'' whose portions abut against the pads are provided on each of both side edges along the magnetic tape sliding direction.

Hereinafter, a method for forming a group of protrusions using screen printing will be described regarding a specific manufacturing method and the effects of this embodiment.

As a screen plate used in the examples of the present invention, a stencil to prevent liquid resin from permeating was formed on a 200 mesh screen with a thickness of 30 μm, and a screen with a thickness of 90 μm was formed.
A pair of plate images were perforated corresponding to the protrusion group shown in Fig. 1, and as a conventional example, a screen made under the same conditions was made with perforations corresponding to the protrusions shown in Fig. 3. A screen plate with a perforated plate image was prepared.

As the liquid resin used for screen printing, the ultraviolet curable resin vvx-5o7 (manufactured by Three Honto) was used as described above.
Using a different type of screen plate, the ultraviolet curing resin was transferred from the plate image to both side edges along the magnetic tape sliding direction of the sliding surface of the 4-channel magnetic head, and then a wavelength of 365 nm and an illumination intensity of 200 mW/cm were applied. UV rays were irradiated for 30 seconds to produce 1 a magnetic head each having a protrusion group shown in FIG. 1 according to the wooden embodiment and a protrusion group shown in FIG. 3 according to the conventional example. In order to confirm the adhesion between the magnetic head sliding surface and the ultraviolet curable resin for these magnetic heads, a thermal cycle test was conducted for 200 cycles of -40°C for 30 minutes and 80°C for 30 minutes. Comparing the adhesion status of ultraviolet curing resin from the surface,
In the present example, no peeling of the protrusions was found, whereas in the conventional example, 6 pieces were found to have partially sided, and 2 pieces were missing due to complete lateral deviation.

FIG. 2 is a plan view showing the structure of a magnetic recording medium sliding surface of a magnetic head according to another embodiment of the present invention, and in the figure, the same components as in FIG. 1 are designated by the same numbers.

In this embodiment, a group of oval protrusions 7a, 7a whose longitudinal direction is perpendicular to the sliding surface of the magnetic recording medium are provided.
A portion of each protrusion will abut the pad. Note that the contact position of the pad is within the broken line in FIG.

It is clear that the magnetic head shown in FIG. 2 can also provide the same effect as the magnetic head shown in FIG. 1.

The shapes of the protrusion groups are not limited to the shapes shown in FIGS. 1 and 2, and even if the shapes within the group are different, or the heights of the protrusions within the group from the magnetic head sliding surface are different. A similar effect can be obtained.

[Effects of the Invention] As explained above, according to the magnetic head of the present invention, the pressure contact force of the pad can be reduced and the magnetic tape can be run stably, and the magnetic head has excellent environmental resistance and little change over time. You will get the head.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a magnetic head embodying the present invention, FIG. 2 is a perspective view of a conventional magnetic head, and FIG. 3 is a tape slider of a magnetic head showing another embodiment of the present invention. FIG. 3 is a plan view showing a moving surface. 3, the magnetic head sliding surface 4, the magnetic core 5, the magnetic tape 6, the pad pressure contact position 7.7. 7a and 7a'', the protrusion group 8, the protrusion a, and the magnetic tape sliding direction G are magnetic gaps, respectively.

Claims (1)

[Claims] (1) In a magnetic head that magnetically records or reproduces information by sliding relative to a magnetic tape that is pressed against a pad, the pressure contact force of the pad comes into contact with a portion of the pad that protrudes from both side edges of the magnetic tape. 1. A magnetic head characterized in that a group of protrusions that reduce friction are provided on a sliding surface of the magnetic head.