JPS62192025A - Magnetic disk signal recording system - Google Patents

Abstract

PURPOSE:To reduce a servo write time, and to prevent a disk from being injured, by applying a magnetic inversion on a part, the temperature of which is raised beyond a Curie point temperature, and writing a servo data. CONSTITUTION:A laser beam 7 is irradiated on a disk medium 1 magnetized in one direction, and the temperature at a part of the disk medium 1 is raised beyond the Curie point temperature, and the magnetic inversion is applied only on the part, and the servo data is written on the disk medium 1. In this way, the servo write time to the disk medium can be reduced, and it also causes a cost reduction.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a servo bias recording method on a magnetic disk.

[Technical background of the invention and its problems]

In hard disk drives and some floppy disk drives, a method is used in which servo information is written on the disk in advance so that the magnetic head accurately traces the track on which data is recorded and tracking is performed accordingly. In the case of hard disks, servo bit information is often recorded on one side of a large number of stacked disk media, and the head is traced according to this information.

In addition, some hard disks and floppy disks have servo information recorded in a part of the data track, and there is also a method of tracking according to this.

In any case, before assembling the disk bed, the data is recorded on the disk medium using a dedicated servo writer. Recording is performed using a magnetic head, and the temporary disks are passed one by one to a servo writer, so when producing a disk device for large appetizers, only one servo writer is required to open the S.
There was also the threat of being forced into a corner, and to solve this problem it was necessary to prepare multiple expensive servo writers. In addition, servo writing is performed using a magnetic head, and the hard disk platform head is exposed to minute amounts of floating particles and dust, which can cause accidents such as crashes and scratches on the disk medium when the head is inserted. Although there is a high possibility that the head is in contact with the disk medium in the case of a Florabee disk, there is still the risk of causing an accident such as scratching the disk medium.

Another disadvantage is that the time required to set the head on the disk medium is negligible.

[Purpose of the invention]

The object of the present invention is to provide a method for improving the drawbacks of the conventional servo writing method and enabling servo writing at high speed and without causing scratches on the disk.

[Summary of the invention]

This invention applies heat from light or direct heat from a heat source to a disk medium magnetized in one direction to raise a part of the disk medium above the Curie point temperature and reverse the magnetization of only that part. It is designed to incorporate data.

〔Effect of the invention〕

According to the present invention, the time required for servo writing to a disk medium is shortened, and there is no need to install a large number of expensive servo writers. Further, the disk is not damaged during servo writing, and the number of defective disk media is reduced, resulting in cost reduction.

The time required for setting the matahead is also significantly reduced.

[Embodiments of the invention]

The principle of the invention is shown in FIG. First, disk media fl)
is magnetized in one direction as shown in la1. The method of magnetization is to rotate the disk medium (1) and apply a magnetic field with a grinding stone or slowly move a permanent magnet closer and further away, and the disk will be magnetized uniformly in the direction of rotation. When a laser beam (22) is applied to the thus magnetized disk medium +11 as shown in +b), the temperature of the applied part (23) increases, and when the temperature reaches the Curie point or higher, the temperature of the applied part (23) increases.
23) no longer has a direction of magnetization. And then (C
), bias magnetization (26
) is applied in the opposite direction to the initial magnetization direction, the applied part (23
) becomes H with the unidirectional magnetized part (24) in the process of decreasing temperature.
The region magnetized in the bias magnetization direction due to the difference in c (26
) appears.

FIG. 1 shows the configuration of a servo writer using laser light based on this principle. A disk medium (1) is being rotated by a motor (2). This disk medium (
1) A laser beam (force) is irradiated onto the object.

The laser beam (7) is generated from a laser beam (m6+3), passes through an optical modulator (4), is redirected by a mirror (5), and then is focused onto the surface of the disk medium [1] by a lens (6). is being squeezed. A modulation signal from a pattern generator (8) is applied to the optical modulator (4). The pattern generator (8) is controlled by the controller (9) and generates a servo pattern signal in response to the rotation of the motor. The mirror (5) moves VC in the inner and outer circumferential directions of the disk medium and writes servo data on the entire servo surface of the disk medium. medium fx)
A bias magnetization is applied to by a bias magnet (10).

FIG. 3 shows an array fa) of servo data patterns recorded on the surface of the disk medium and reproduction No. 1+b) read out by a magnetic head. First, the servo pattern row (a) will be explained.

The dotted portions are the boundaries between the tracks, and one track is the portion shown in (34). The head (31) is in an on-track state. Of the servo patterns written on the track, the shaded portion (32) is written by a laser and magnetized in the opposite direction, and the white portion is magnetized in one direction. Transfer this pattern to the head (3
When reproduced in step 1), a waveform peak appears at the boundary between the unidirectionally magnetized portion and the reversely magnetized portion, resulting in a waveform as shown in (b). In order to make the head on-track, the position of the head may be adjusted so that the reproduction voltage ranges ' and '8' of pattern A and pattern B are at the same level.

The servo pattern shown here is just an example, and there are many other patterns that have been devised, and the present method can of course be applied to writing those patterns.

As described above, according to the method of Embodiment 1, the servo write is performed without touching the disk, so that no scratches are left on the disk medium. This has the advantage of reducing the time required to set the head. Furthermore, by increasing the power of the laser, servo writing can be performed in a much shorter time than servo writing using a magnetic head.

[Other embodiments of the invention]

FIG. 4 shows another implementation of the invention. In the above embodiment, the disk medium was rotated, but the disk medium (1) was fixed and the mirror (41) was rotated to generate the laser beam (43).
) may be scanned. If you use this method, rotating a floppy disk will cause a large amount of up and down movement, making it difficult to focus the laser beam.

If the disk medium is fixed on a flat surface, there are advantages such as ease of recording. Further, the trouble of fixing the disk medium to the spindle is also avoided.

FIG. 5 also shows another real tA sequence of the present invention. disk medium f
A mask (51) having a part that allows light to pass and a part that does not allow light to pass is placed over the tl, and a heat beam such as infrared rays or a strong laser beam is uniformly irradiated. The beam may be scanned by constricting laser light.

With this method, a pattern is instantaneously formed over the entire surface of the disk medium, so the servo write time is greatly reduced.

FIG. 6 also shows another embodiment of the present invention. Disk media (1
) into the heated mold (61). The mold has unevenness, and the parts that come into contact with the disk medium lose their magnetization.

This method also allows patterns to be formed in an instant.

FIG. 7 is also another embodiment of the present invention. disk medium fi
1 is a perpendicular magnetization medium that exhibits magnetization anisotropy in the perpendicular direction.

Even if the disk medium f1) is such a medium, if the initial magnetization is uniformly af in the perpendicular direction and a reverse bias magnetic field (71) in the perpendicular direction is applied, a servo pattern can be recorded even on a stationary medium. I can do it.

The pattern guided by light or the like may be a pattern other than the force S and data No. 100, which have been explained only as servo patterns, that is, an index pattern or an ID code recorded for each sector.

That is, it is clear that the method of the present invention can be used for anything other than data that needs to be recorded in advance.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the configuration of a servo writer according to the present invention, FIG. 2 is a diagram showing the principle of servo signal recording according to the present invention, and FIG. FIG. 4 shows the diagram. FIGS. 5, 6, and 7 are examples showing other embodiments of the present invention. l...Disk medium, 3...Laser oscillator, 4...
- Optical modulator, 7... Laser beam, 8... Pattern generator. 10...Bias magnet. Agent Patent Attorney Nori Chika 7! ! Same as right
Bamboo flower Kikuobu Fig. 1 (C) Fig. 2 Fig. 3 Flute Fig. 4 Fig. 6 Fig. 6 Fig. 1, -7 Fig. 7

Claims (2)

[Claims] (1) The recording medium of a magnetic storage device that records and reproduces data using a magnetic head is uniformly magnetized in one direction, and a part of the medium is heated to a temperature above the Curie point by heat from light or direct heat. By simultaneously applying a magnetic bias in the opposite direction to the uniformly magnetized direction, parts of the medium surface are magnetized in one direction and parts magnetized in the opposite direction, and this recorded information is A magnetic disk signal recording method characterized in that the signal is used as a control signal when reading data from a magnetic recording medium. (2) The magnetic disk signal recording method according to claim 1, wherein the control signal is a servo signal used for head positioning.