JPS5979411A - Magnetic head - Google Patents

Abstract

PURPOSE:To perform the reproduction with high S/N with reduced noises despite an off-track produced with positioning of a magnetic head by using a ring type thin film magnetic head which forms a closed magnetic path by means of a recording medium and therefore generating a magnetic field having high vertical performance. CONSTITUTION:For the form of an area where a contact is obtained between a vertically magnetized film 2-6 and magnetic films 2-2 and 2-3 of a thin film magnetic head, the width w1 of the film 2-2 provided at the outflow side of the film 2-6 is set larger than the width w2 of the film 2-2 at its tip side. For a positioning shift of a magnetic head, the same recording shift exists between tracks A and B (shown in the figures). However the width w2 of a gap 2-5 to be reproduced is smaller than the recording width w1. Thus the reproduction width w2 is included within the track B despite a position shift of the magnetic head, and it is possible to reproduce only the signals on the track B. In this case, the width difference D of the film 2-2 of the magnetic head is decided in consideration of the mechanical positioning accuracy of the magnetic head.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to the shape of a magnetic film of a thin film magnetic head that records on a perpendicularly magnetized film.

Perpendicular magnetic recording, which uses a perpendicularly magnetized film with perpendicular orientation such as cobalt chromium as a recording medium, has been proposed as a method that can perform recording with a higher degree of intelligence than conventional magnetic recording methods. As shown in FIG. 1, a typical magnetic head in this case has a main pole 1-1 made of soft magnetic material B<, \ such as permalloy or amorphous magnetic metal, and a winding 1-3 on fezite or the like. The 1qth auxiliary magnetic pole 1-2 is made up of auxiliary magnetic poles 1-2. By providing permalloy, amorphous magnetic metal, etc. as the underlayer of the perpendicularly magnetized film 1-4, the magnetic field generated in the perpendicularly magnetized film 1-4 by the main magnetic pole 1-1 and the auxiliary magnetic pole 1-2 is Since the perpendicularity to the film surface of 1-4 is high, recording suitable for a perpendicular magnetization film can be performed. However, main magnetic pole 1-1. Auxiliary magnetic pole 1-2. Since the magnetization of the perpendicularly magnetized film 1-4 does not constitute a closed magnetic path, there is a problem in recording and reproducing efficiency.

An object of the present invention is to use a ring-shaped thin film magnetic head that forms a closed magnetic path using a recording medium to
It is applied to a perpendicularly magnetized film that generates a highly perpendicular magnetic field, and even if there is off-track caused by the inaccuracy of the magnetic head positioning mechanism, there is little noise (it has a shape that allows playback with a good signal-to-noise ratio). An object of the present invention is to provide a thin film magnetic head.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 is a sectional view of a thin film magnetic head and a recording medium. Generally, in a ring type thin film magnetic head, the gap 2-
Recording is performed by leakage magnetic flux 2-9 generated at 5.
When the traveling direction of the recording medium 2-6.2-7 is the direction of the arrow 2-15, the corner 2-8 at the outflow end, that is, the rear end of the recording medium is sharpened by the magnetic R operation 2-2 of the thin film magnetic head. , and a soft magnetic material 11 such as permalloy as the underlayer of the perpendicular magnetization film 2-6.
By providing g2-7'i, it is possible to create a magnetic flux 2-1O that perpendicularly penetrates the perpendicular magnetization film 2-6, and it is possible to perform recording by taking advantage of the perpendicular magnetization force 1-2-6. can.

As shown in FIG. 2, when the recording medium's jf< is taken in the row direction, there is a lot of recording at the gap 2-5, but eventually the recording at the recording medium outlet end 2-8. It will remain. Therefore, the recording density is not determined by the length of the gap 2-5, but by the speed at the trailing edge of the recording medium, that is, the speed of the recording medium and the recording frequency. The recording density can be increased up to the density determined by the size.

Since the reproduction is performed in the gap 2-5, to increase the resolution, it is sufficient to narrow the gap 2-5, and in the thin film process, it is necessary to narrow the gap 2-5.
．． Even a gap of about 1 μm can be formed with good reproducibility.

On the other hand, when a magnetic head is actually mounted on a magnetic recording device, the position h7 of the magnetic head must be considered because movement between tracks is performed mechanically.

FIG. 3 shows both magnetic fl! of the thin film magnetic head shown in FIG. The positional deviation of the magnetic head when the width W of Mr2-2, 2-3 is the same will be shown. Figure 3 shows perpendicular magnetization film 2-6.
is seen from the thin-film magnetic head side.

First, as shown in FIG. 3, 131, it is assumed that recording with a width W is performed at the outflow end 2-8 of the track AK recording medium. After moving the thin film magnetic head to another track, (1)
Even if you try to record back to track A shown in Figure 3 (2), due to the inaccuracy of the positioning of the magnetic head, it will not be completely aligned with track A, and the position will be slightly shifted as shown in Figure 3 (2). is recorded as track B. In this case, if the lagoonal magnetic head is perfectly aligned with track B during playback,
Although only the signal of track B can be extracted, as shown in FIG. 3 131, the signals of both tracks may be reproduced depending on tracks A and B due to the positional deviation of the magnetic head. Is there a signal for track B? i: L I
/-1d, the signal of the erased part d of track A becomes a sound.

The shape of the part of the magnetic film 2-2, 2-3 of the thin film magnetic head of the present invention in contact with the perpendicularly magnetized film 2-IC is on the outflow side of the perpendicularly magnetized film 2-6, as shown in FIG. A certain magnetic film 2
-2 @w1 is the width '1 of the other magnetic film on the tip side
02 It's wide. Considering the positional deviation of the magnetic head in the same way as in FIG. 3, the recording deviations of tracks A and B shown in FIG. 4 121 are the same, but as shown in FIG. Since the width w2 of -5 is smaller than the recording width w1, even if there is a positional shift of the magnetic head, the playback width will not change. I) 21d) Since the track BK is included, only the signal of track B can be reproduced. The difference in the width of the magnetic film of the thin film magnetic head is determined in consideration of the mechanical positioning accuracy of the magnetic head.

With the thin film magnetic head formed as described above,
By taking advantage of the characteristics of the perpendicular magnetization film, it is possible to record and play back at a higher density than conventional magnetic recording, and because the influence of the positional shift of the magnetic head is slightly reduced, playback with fewer new sounds is possible. can now be done.

[Brief explanation of drawings]

FIG. 1 shows the arrangement of a magnetic head and a recording medium in typical conventional perpendicular magnetic recording. FIG. 2 shows the distribution of thin film magnetic heads and recording media according to the present invention. Fig. 3 explains the positional deviation of the magnetic head caused by the inaccuracy of the positioning accuracy of the magnetic head, and Fig. 4 shows the magnetic head of the present invention which reduces the influence of the positional deviation. FIG. 3 is a diagram showing the principle of the head. 1-1... Main magnetic pole 1-2... Auxiliary magnetic pole 1-3... Winding 1-4... Perpendicular magnetization film 1-5... Soft magnetic film 2-1... Substrate 2... Soft magnetic film 3. Coil 5e of soft magnetic film 4. Gap 6. Perpendicular magnetization film 7. Soft magnetic film 8. Recording medium outflow end 1. (1) Cn) (3) Figure 3 11n (λ)
F3) Figure 4

Claims (1)

[Claims] A magnetic head for recording on a perpendicularly magnetized film, which is a recording medium, characterized in that a rear end core is made of a thin film and is wider than a front end core.