JPH09297904A - Magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a spacing loss in a video head used for a VTR, etc., and to provide a high performance magnetic head. SOLUTION: This magnetic head is constituted so that rounding (R) working of a surface 7 opposite to a magnetic recording medium is performed in the track width direction, and the size of the radius thereof is made larger than that usually performed in the longitudinal direction, and the vertex of the R is made a center of a magnetic gap 3. Further, the parts each ranging 20-40% of the track width outside it are ground at an angle of 30 deg. or more in the width direction, and an area in contact with a recording magnetic medium is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is intended to improve the performance of a recording / playback head used for a VTR, or a video head dedicated to recording and playback, by reducing spacing loss.

[0002]

2. Description of the Related Art Conventionally, various techniques for improving contact between a magnetic recording medium and a magnetic head have been proposed. For example, there is a method in which only the track width portion is used as the surface facing the magnetic recording medium. However, in this method, the contact area with the magnetic recording medium is small, so that the life of the magnetic head is shortened. To compensate for this defect, the output of the magnetic head is reduced if the magnetic gap depth is increased. There is also proposed a method of providing an R shape in the track width direction of the surface facing the magnetic recording medium or in the magnetic head longitudinal direction. However, even in this method, if the cylinder diameter becomes smaller as in recent years, the spacing loss cannot be sufficiently reduced. In addition, the longitudinal direction of the surface of the magnetic head facing the magnetic recording medium is set in the longitudinal direction of the magnetic recording medium.
It is also proposed to change the shape on the exit side. However, with this method, when the speed of the magnetic recording medium changes, such as slow reproduction, the spacing loss increases, and a sufficient effect cannot be expected.

[0003]

As described above, the conventional technique has a drawback that the spacing loss cannot be sufficiently reduced. The present invention eliminates these drawbacks and, fully,
An object is to provide a magnetic head that can reduce spacing loss.

[0004]

In order to achieve the above-mentioned object, the present invention is designed so that, after the usual magnetic recording medium facing surface processing, the center of the magnetic gap becomes the highest.
In addition, the magnetic recording medium has a shape that most closely contacts the magnetic head. That is, by making the R shape in the width direction of the magnetic recording medium facing surface larger than the longitudinal direction, the magnetic recording medium causes an action of winding the magnetic head in the width direction, and is 20 to 40% of the track width. From
This effect is promoted by making the shape sharply lower at an angle of about 30 degrees or more. As a result, the distance between the magnetic head and the magnetic recording medium is reduced, spacing loss can be reduced, and the performance of the magnetic head can be maximized.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIG.
This will be described in detail with reference to FIG. FIG. 1 is a magnetic core before winding in which the magnetic recording medium facing surface processing according to the present invention has been completed, and FIG. 2 is an enlarged view of the magnetic recording medium facing surface of the magnetic core of FIG. 1 is an I core, 2 is an E core, 3 is a magnetic gap, 4 is a winding groove, 5 is winding groove filling glass, 6 is a metal magnetic thin film, 7 is a magnetic recording medium facing surface, and 8 is about 30 degrees or more. A portion of the width direction of the magnetic core ground at an angle, 9 shows an interference fringe of an interference microscope. Since the magnetic head of this embodiment is a composite magnetic head in which the alloy magnetic thin film 6 is sputtered on an oxide magnetic material, first, a V groove serving as a track width control groove is formed on the oxide magnetic material, and then the alloy magnetic material is formed. A thin film 6 is formed, and the V groove is filled with the winding groove filling glass 5 having a low softening point in an electric furnace or the like. Furthermore, the winding groove 4 is provided on one side of the magnetic core to be the E core 2 by the conventional method, and the E core 2 and the I core 1 are provided.
High softening point glass is formed by sputtering on the surface where the magnetic gap 3 is formed. After that, by melting and fixing the high softening point glass formed on the I core 1 and the E core 2 in an electric furnace or the like, the E core 2 and the I core 1 are joined and the R surface polishing machine is used. The R processing of the magnetic recording medium facing surface 7 is performed.

Thereafter, in order to process the magnetic recording medium facing surface 7 of the present invention, the magnetic core formed by joining the above E core 2 and I core 1 is polished by a tape running machine. That is, a magnetic core to be ground is set on a holding jig, the holding jig is swung in the track width direction, and an R shape processing in the track width direction is performed with a polishing tape of a tape running machine. At this time, by observing the magnetic recording medium facing surface 7 with an interference microscope and changing the swing width and angle of the holding jig and the polishing tape tension of the tape running machine so as to obtain a desired R shape, the desired magnetic recording medium is obtained. Processing of the facing surface 7 is obtained. Further, in order to grind in the magnetic head width direction at an angle of about 30 degrees or more from a portion 20 to 40% away from the track width portion, the following may be performed. First, the magnetic core that has been processed as described above is cut into a predetermined thickness with a wire saw, a slicing machine, or the like, and the magnetic chip that has been cut is bonded to a base.
After this, using the tape running machine described above, the magnetic chips adhered to the base are set on a holding jig that can hold one by one. This time, the jig is not rocked, the portion to be ground is fixed, and the polishing tape is run at a desired angle, whereby polishing can be performed at the desired angle. After the above steps, if the winding is performed by a known method, the magnetic head of the present invention can be obtained.

[0007]

The magnetic head according to the present invention can reduce the spacing loss by about 30 dB as compared with the conventional one.
The recording / reproducing capability for the magnetic recording medium is improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing a magnetic head according to an embodiment of the present invention before a winding step.

2 is an enlarged view of the magnetic recording medium facing surface of FIG.

[Explanation of symbols]

1: I core, 2: E core, 3: magnetic gap, 4: winding groove, 5: winding groove filling glass, 6: metal magnetic thin film, 7: magnetic recording medium facing surface, 8: about 30 degrees or more A magnetic recording medium facing surface in which the track width direction of the magnetic core is ground at an angle, 9:
Interference fringes observed with an interference microscope.

Claims (1)

[Claims] 1. In a video head whose surface facing the magnetic recording medium is larger than the track width, the center of the magnetic gap is the highest and gradually decreases as it approaches the track width control groove direction, and the change is in the longitudinal direction of the magnetic head. The magnetic head is ground in the width direction of the magnetic head at an angle of about 30 degrees or more from a portion 20% to 40% apart from the track width portion.