JPH01273207A - Magnetic head for perpendicular magnetic recording - Google Patents

Abstract

PURPOSE:To reduce the spacing loss between the title magnetic recording medium without increasing the pressure of the head pad by specially designing the shape of the surface of the magnetic head which is confronted with the recording medium so as to produce negative pressure when the recording medium is run. CONSTITUTION:The ferrite 2 of a main magnetic pole section is formed in such a way that a notch-like groove is provided on the rear section in the sliding direction on the sliding surface of a ferrite block 1 for return path and a projecting part is formed at the center of a U-shaped groove opened on the downstream side in the flow 7 of a gaseous body. Then an excitation coil 3 is wound around the ferrite 2 and the soft magnetic thin film 5 of a main magnetic pole held between nonmagnetic sliders 4a and 4b is fitted to the ferrite 2. When a recording medium is slid on the vertical recording magnetic head thus formed, the air flowing the circumference of the recording medium running at a high speed enters into the section (b) and expands, resulting in a pressure drop. Therefore, magnetic recording and reproduction are performed in a state where the magnetic recording medium rotating at a high speed while the medium is contacted with the magnetic head is pressed against the magnetic head by the negative pressure pressure produced in the circumference of the main magnetic pole.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic head for perpendicular magnetic recording that enables high recording density recording and reproduction.

[Contents and problems of conventional technology]

Currently, so-called "still video" is being developed as a still image storage method to replace silver photographs, in which image signals are recorded and played back on a 2-inch floppy disk. Furthermore, the recording and reproducing of high-definition images has been attracting attention in order to fully utilize the high-density recording potential of the perpendicular magnetic recording system to realize recording and reproducing of high-quality video.

However, in order to record and reproduce video signals, it is necessary to rotate the disk at 3,600 revolutions per minute, and in the case of a 2-inch floppy disk, the magnetic head This was an obstacle to practical application.

In other words, in order to achieve high-density recording and reproduction, it is necessary to minimize the spacing loss between the magnetic head and the medium, but this high-speed rotation causes the magnetic recording medium to float away from the magnetic head. A problem is occurring.

Furthermore, in order to ensure stable head touch, it is necessary to increase the pressure on the head pad, which impairs the durability of the medium.

[Purpose of the invention]

The present invention solves this problem by changing the shape of the surface of the magnetic head for perpendicular magnetic recording that faces the magnetic recording medium, creating negative pressure against the running of the magnetic recording medium, and increasing the pressure on the head pad. An object of the present invention is to provide a magnetic head for perpendicular magnetic recording in which the spacing loss between the magnetic head and the magnetic recording medium is reduced without causing any problems.

[Structure of the invention]

FIG. 1 is a perspective view of a magnetic head according to the present invention, and FIG. 2 is a sectional view of the magnetic head according to the present invention.

The perpendicular magnetic recording medium runs in the direction indicated by the arrow in FIGS. 1 and 2. In the magnetic head for perpendicular magnetic recording of the present invention, the ferrite block 1 for the magnetic flux return path has a U-shape open on the downstream side of the gas flow, and its cross section in the running direction is F-shape. Here, an excitation coil 3 is wound around the main pole ferrite (convex part) 2 at the center of the groove, and a main pole soft magnetic thin film made by sputtering or the like is placed on the nonmagnetic slider 4a sandwiched between nonmagnetic sliders 4a and 4b. 5 is attached.

When a perpendicular magnetic recording medium is run on the magnetic head for perpendicular recording of the present invention, as shown in FIG. , this part will be under high pressure.

However, when the air enters part b, it expands and the pressure decreases. A small portion of the air flows to the 0 part, generating a force that pushes up the magnetic recording medium, but most of it flows to both ends of the central ferrite block.
It reaches part d and flows out to the outside of the head while remaining under negative pressure.

Due to the above operation, the gas flow becomes negative pressure around the main magnetic pole, and the magnetic recording medium, which is in contact with the magnetic head and rotates at high speed, is pressed against the magnetic head. That is, the present invention provides a ferrite block in which a groove is formed on the sliding surface side so as to cut out the rear part of the sliding part, and a convex part is formed in the center of the groove;
This magnetic head for perpendicular magnetic recording is characterized in that a main pole is provided above the convex portion, and an excitation coil is arranged around the convex portion.

Margin below [Explanation based on examples] Examples of the present invention will be described below.

Magnetic head for perpendicular magnetic recording of the present invention (main pole film thickness: 0
．． 2μm, track width: 50μm), two-layer perpendicular magnetic recording medium (CoC
r: 0.15μm, N4Fe: 0.50μm
) was formed and its electromagnetic conversion characteristics were measured.

[Comparative example]

The so-called φ-type head (main pole thick film: 0.
2 μm, track width: 50 μm), the electromagnetic conversion characteristics of the same medium as in the example were measured.

FIG. 5 shows the recording current and reproduction output characteristics of Examples and Comparative Examples of the present invention, and FIG. 6 shows the recording density characteristics.

The embodiments of the present invention exhibited higher reproduction outputs even at higher recording densities than conventional Φ-type heads, and clearly achieved the object of the present invention.

〔Effect of the invention〕

As described above, according to the present invention, a 2-inch high image quality perpendicular magnetic recording magnetic head was obtained.

Margin below

[Brief explanation of the drawing]

FIG. 1 is a perspective view of the surface of the magnetic head for perpendicular magnetic recording according to the present invention that faces a magnetic recording medium. FIG. 2 is a sectional view taken along line A-A in FIG. 1. FIG. 3 is a diagram schematically showing the flow of air when the magnetic head for perpendicular magnetic recording according to the present invention runs over the surface of a magnetic recording medium. (a) is a perspective view, (b) is a sectional view. FIG. 4 is a cross-sectional view showing a φ-type magnetic head, which is a conventional magnetic head for perpendicular magnetic recording. FIG. 5 is a diagram showing the reproduction output characteristics of the magnetic head for perpendicular magnetic recording, where the song MB shows the characteristics of the magnetic head according to the present invention, and the song 'MAC shows the characteristics of the φ-type magnetic head shown in FIG. FIG. 6 is a diagram showing the recording and reproducing characteristics of a magnetic head for perpendicular magnetic recording. The curved line is the characteristic of the magnetic head according to the present invention, and the curve E is the characteristic of the φ-type magnetic head shown in FIG. Margin 1 below: Ferrite block for return path. 2...Main magnetic pole part ferrite (convex part). 3... Excitation coil. 4a, 4b...Nonmagnetic slider. 5... Main pole soft magnetic thin film. 6...Recording medium. 7... Gas flow. Patent applicant: Tohoku Metal Industry Co., Ltd. Figure 1 Figure 2 Figure 4 Figure 3/<bt Figure 6

Claims (1)

[Claims] A ferrite block has a groove cut out at the rear of the sliding surface, and a convex part is formed in the center of the groove, and a main magnetic pole is provided above the convex part, and a magnet for excitation is provided around the convex part. A magnetic head for perpendicular magnetic recording characterized by a coil arrangement.