JPH05342526A - Magnetic head - Google Patents

Abstract

PURPOSE:To provide the magnetic head which suppresses crosstalk noise even at a large offtrack quantity and increases the density of tracks by executing recording with magnetic patterns having two azimuth angles arrayed across one track. CONSTITUTION:A head core 2 within a recording and reproducing element of the magnetic head constituted of the recording and reproducing element and a head slider 1 is provided with a V-shaped head gap 4 with the longitudinal center line of the head core as a symmetrical axis. The V-shaped magnetic patterns are arrayed vertically in one track when the recording is executed by this magnetic head and, therefore, the W-shaped magnetic patterns are formed on the two adjacent tracks and the magnetic pattern forming direction of the boundary of the respective tracks takes a nonparallel form. The crosstalk noise is diminished by the azimuth loss even if reproducing is executed at the time of an off-track. As a result, the need for guard bands is lessened and since the reproducing is possible in spite of a large off-track quantity, the track density is easily increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to magnetic recording and reproduction in a magnetic disk device.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIG. 6, FIG. 7 or FIG.

FIG. 6 shows an example of a magnetic head used for recording and reproducing in a conventional small hard disk device. The magnetic head comprises a recording / reproducing element and a head slider 1 which moves on the surface of the magnetic disk and serves as a base of the recording / reproducing element.
The recording / reproducing element includes a head core 2 that transmits a magnetic flux, and a coil 3 that is attached to the head core 2 to generate electromagnetic induction. The head core 2 is provided with a head gap 4 for exchanging magnetic flux with the magnetic disk. The azimuth angle of the head gap is usually set to 0 degree.

Information recorded using this magnetic head forms a magnetic pattern as shown in the enlarged view of FIG. In other words, it is a form in which the minute rectangular magnets 3 having a width slightly smaller than the track pitch are aligned and arranged with their magnetic poles oriented in the longitudinal direction of the track. Width of this magnet T _W
Is smaller than the track pitch T _P because the guard band 4 is provided to reduce mutual influence between the tracks.

FIG. 8 shows a state in which the off-track has occurred. If this state is left as it is, even if the guard band 3 is provided, the head gap direction and the magnetic pattern forming direction of the adjacent track are substantially parallel to each other. Not only the magnetic pattern is reproduced, but also the magnetic patterns of adjacent tracks may be reproduced as crosstalk.

[0006]

When the head is positioned on the target track, off-track may occur depending on the structural conditions of the positioning mechanism, temperature changes, and the like. FIG. 8 shows the state in which the off-track has occurred again. If this is left as it is, even if the guard band 3 is provided, the head gap direction and the magnetic pattern forming direction of the adjacent track are almost parallel, and therefore the magnetic pattern of the target track is formed. Not only is reproduced, but the magnetic patterns of adjacent tracks are also reproduced as crosstalk. This prevents accurate reproduction of information.

Therefore, the conventional technique has a problem that the off-track amount must be reduced or the guard band width T _G must be increased in order to suppress the occurrence of crosstalk while keeping the same track width.

[0008]

In order to solve the above-mentioned problems, a magnetic head having a recording / reproducing element having two non-parallel head gaps provided in the head core in a row in the longitudinal direction of the head core. Use the means to record.

Further, there is used a means for recording with a magnetic head having a recording / reproducing element constituted by attaching a coil to a head core having a V-shaped head gap.

[0010]

When recording is performed using the head of the present invention, each magnetic pattern is formed so as to have different azimuth angles on both sides with one line parallel to the longitudinal direction of the track as a boundary. In any two tracks, the magnetic pattern forming directions on the respective boundaries are non-parallel.

Even if an off-track occurs when reproducing this, the influence of azimuth loss is large in the magnetic pattern reproduced as crosstalk, so that the noise when reproducing the target magnetic pattern becomes small.
This means that the guard band is almost unnecessary and the reproduction is possible even if the off-track amount becomes large.

Therefore, the track density can be increased and the disk capacity can be increased.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic head of the present invention will be described with reference to FIGS.

FIG. 1 is a perspective view of a magnetic head used for recording / reproducing of a small hard disk device according to the present invention.
This magnetic head comprises a recording / reproducing element and a head slider 1 which moves on the surface of a magnetic disk and serves as a base of the recording / reproducing element. The recording / reproducing element includes a head core 2 that transmits a magnetic flux, and a coil 3 that is attached to the head core 2 to generate electromagnetic induction. The head core 2 has a structure in which two head cores 2a and 2b of the same size are joined with a thin plate 5 of a diamagnetic material sandwiched therebetween so that the size thereof becomes one head core size. The head cores 2a, 2b are provided with head gaps 4a, 4 for exchanging magnetic flux with the magnetic disk.
b is provided. These head gaps have opposite azimuth angles of about 10 degrees so that when the head core 2 is formed, the thin plate 5 has a symmetrical V-shape.

Information recorded using this magnetic head forms a magnetic pattern as shown in the enlarged view of FIG. 1
Looking at the two tracks, the V-shaped minute magnets are arranged so as to be in tandem with respect to the longitudinal direction of the tracks, with their bent tips in the same direction. Moreover, one magnetic pattern is divided into two magnetic patterns having different azimuth angles on both sides of the thin plate 5 as a boundary. Therefore, since the magnetic pattern on each track forms a V-shape, the magnetic patterns on the boundary side of any two adjacent tracks are not parallel to each other. There is.

FIG. 3 shows a state where off-track has occurred during reproduction. In the enlarged view 1 of this figure, the target information can be reliably reproduced because there is no azimuth loss. 2 is a part for reproducing the target information even if there is an azimuth loss. Reference numeral 3 is a portion where an adjacent track is reproduced.

In the prior art, as shown in the enlarged view of FIG. 8, since there is no azimuth loss in the portion 3 where the adjacent track is reproduced, crosstalk occurs during reproduction, resulting in a large noise. However, in the case of the present invention, since the azimuth loss is present in the portion 3 where the adjacent track is reproduced, the noise generated during reproduction becomes small. From the above, it can be seen that there is no need to provide a guard band, and reproduction can be performed even when the off-track amount is close to half the track pitch. This means that reliable reproduction is possible even if the track density is increased.

As shown in FIG. 4, when a magnetic head in which a V-shaped head gap 4 is provided in one head core 2 without sandwiching a thin plate is used, the same effect as when the magnetic head of FIG. 1 is used is obtained. There is expected. Because the magnetic pattern is V
Since the minute V-shaped magnets are arranged in a row in the longitudinal direction of the track with their bent ends facing in the same direction, even if off-track occurs during playback, crosstalk noise is affected by azimuth loss. This is because it becomes smaller.

As shown in FIG. 5, the same effect can be expected when the head gap is discontinuous with the thin plate 5 of diamagnetic material as a boundary and is not symmetrical about the longitudinal centerline of the head core. Even in this case, the drawn magnetic pattern is in a form such that the formation directions of the magnetic patterns on the boundary sides of the respective tracks are not parallel in any two adjacent tracks.

Further, the magnetic head used for recording / reproducing of a small hard disk device has been described above, but the same effect can be expected when it is used for a magnetic head used for recording / reproducing of a floppy disk device.

[0021]

When the magnetic head of the present invention is used for recording, a magnetic pattern having two azimuth angles can be simultaneously formed on one track by using only one magnetic head. The formation directions of the magnetic patterns on the respective tracks in the vicinity can be made non-parallel.

As a result, even if the off-track occurs, the crosstalk has an azimuth loss, so that it does not become a large noise when the target magnetic pattern is reproduced. Therefore, a guard band is almost unnecessary, and reproduction is possible even when the off-track amount becomes large.

Therefore, the density of the tracks can be increased, and the capacity of the disk can be increased.

[Brief description of drawings]

FIG. 1 is a perspective view of a recording / reproducing magnetic head of a small hard disk device according to the present invention.

FIG. 2 is a magnetic pattern diagram when recording is performed using the magnetic head of the present invention.

FIG. 3 is a state diagram of an off-track according to the present invention.

FIG. 4 is a perspective view of a recording / reproducing magnetic head of a small hard disk device according to the present invention.

FIG. 5 is a perspective view of a recording / reproducing magnetic head of a small hard disk device according to the present invention.

FIG. 6 is a perspective view of a recording / reproducing magnetic head of a conventional small hard disk device.

FIG. 7 is a magnetic pattern diagram when recording is performed using a conventional magnetic head.

FIG. 8 is a state diagram of a conventional off-track.

[Explanation of symbols]

 1 head slider 2 head core 3 coil 4 head gap 5 thin plate of diamagnetic material

Front page continued (72) Inventor Yuji Yagi 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. 72) Inventor Kiyoshi Masaki 1006, Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Tatsuhiko Inagaki, 1006, Kadoma, Kadoma, Osaka Prefecture

Claims (2)

[Claims] 1. A magnetic head used in a magnetic disk device, wherein a recording and reproducing operation is carried out by attaching a coil to a head core formed by arranging and joining two head cores having head gaps that are not parallel to each other. A magnetic head having an element. 2. A magnetic head used in a magnetic disk device, comprising: a head core having a V-shaped head gap;
A magnetic head having a recording / reproducing element constituted by attaching a coil.