JPH09138926A - Magnetic disk magnetizing device and magnetizing method - Google Patents

Abstract

Kind Code: A1 A magnetic disk having unevenness indicating a servo signal is always magnetized optimally at any position on the magnetic disk without being influenced by the characteristics of each magnetic head. Provided is a magnetizing device and a magnetizing method. SOLUTION: When magnetically writing a servo signal by magnetizing a magnetic disk having concavities and convexities indicating a servo signal so that the concave portion and the convex portion have different magnetization directions, first, The optimum value of the recording current is measured at a plurality of positions in the radial direction of the magnetic disk. Next, the relationship between the radial position of the magnetic disk and the optimum value of the recording current is calculated from the above measurement results. Then, based on the above calculation results, the magnetic disk is magnetized while changing the recording current depending on the radial position of the magnetic disk.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetizing device and a magnetizing method for a magnetic disk having irregularities indicating servo signals. That is, the present invention relates to a magnetizing device and a magnetizing method which magnetically write a servo signal by magnetizing a concave-convex and a convex part so that the magnetization directions are different with respect to a magnetic disk having irregularities indicating a servo signal. It is a thing.

[0002]

2. Description of the Related Art A magnetic disk is required to have a high recording density, and in order to realize this, further improvement in track density is desired. Here, in order to increase the track density, it is required that the magnetic head be accurately positioned with respect to the magnetic disk, that is, tracked.

Usually, in tracking on a magnetic disk, a signal for positioning, that is, a servo signal is written in advance on the magnetic disk, and based on the servo signal written in advance, the track is centered on the target track. The position of the magnetic head is controlled by an actuator or the like so that the magnetic head is positioned. Here, as a matter of course, the servo signal needs to be accurately written on the magnetic disk, and the tracking accuracy is determined depending on whether or not the servo signal is accurately written on the magnetic disk.

Conventionally, as a method of writing such a servo signal on a magnetic disk, an apparatus called a servo writer equipped with a magnetic head is used to magnetically directly write the servo signal on the magnetic disk by the magnetic head of the servo writer. Methods have been used. However, in this method, the accuracy when writing the servo signal on the magnetic disk is determined by the accuracy of the head feeding mechanism that sends the magnetic head onto the magnetic disk to write the servo signal. Therefore, in such a method, a dedicated magnetic head feeding mechanism having a particularly high accuracy is required as the head feeding mechanism. Further, even a dedicated magnetic head feed mechanism is accompanied by mechanical operation, so that there is a limit to the accuracy, and the accuracy of this head feed mechanism hinders the densification of tracks.

Therefore, instead of directly writing servo signals on a magnetic disk with a magnetic head, a method has been developed in which irregularities corresponding to servo signals are provided in advance on a substrate made of a non-magnetic material such as plastic or glass. ing. In this method, first, a technique such as photolithography is applied to form irregularities corresponding to servo signals on the substrate, and then,
A magnetic layer is formed on the substrate on which the concavities and convexities are formed to form a magnetic disk, and then magnetic signals of opposite polarities are written in the portions corresponding to the concave portions and the portions corresponding to the convex portions, which are used as servo signals.

In such a method, the accuracy of the servo signal is determined by the accuracy of the patterning of the concavo-convex patterning, but the patterning by photolithography or the like is far more than that which involves mechanical operations such as a head feed mechanism. The accuracy is excellent. Therefore, according to this method, it is possible to accurately write the servo signal on the magnetic disk, and as a result, it is possible to improve the track density. Moreover, since such irregularities can be formed very easily by injection molding, there is also an advantage that such a magnetic disk can be manufactured in large quantities and at low cost.

[0007]

By the way, conventionally, when writing a servo signal to a magnetic disk having such an unevenness, the magnetic head is set so that the magnetization directions of the concave portion and the convex portion of the magnetic disk are opposite to each other. Is performed by magnetizing a magnetic disk. That is,
The servo signal is written by scanning and magnetizing the magnetic disk with the magnetic head while supplying a constant recording current to the magnetic head. Here, the scanning of the magnetic disk by the magnetic head is performed while rotating the magnetic disk.
This is performed by moving the magnetic head from the inner circumference to the outer circumference or from the outer circumference to the inner circumference of the magnetic disk, whereby servo signals are magnetically written on all tracks of the magnetic disk.

As described above, when the magnetic disk is magnetized by the magnetic head and the servo signal is written, the magnetic head slightly floats on the magnetic disk. The floating characteristic of such a magnetic head is The difference in the linear velocity between the inner and outer circumferences of the disk, the attitude of the magnetic head, that is, Ya
It changes depending on the location on the magnetic disk due to the change of the w angle. When the flying characteristic of the magnetic head changes, the recording / reproducing characteristic of the magnetic head naturally changes.

Therefore, as described above, in the conventional method of magnetizing the magnetic disk by applying a constant recording current to the magnetic head, the magnetized state varies depending on the location on the magnetic disk. . Therefore, in the conventional magnetic disk magnetizing method, the servo signal is not uniformly written over the entire magnetic disk, and it is impossible to supply a high-quality magnetic disk.

Further, the characteristics of the magnetic head such as the above-mentioned levitation characteristics are likely to vary depending on the individual magnetic heads. Therefore, when different magnetic heads are magnetized, they are magnetized under the same conditions. Sometimes the state changed. Therefore, the conventional magnetic disk magnetizing method has a problem that it is difficult to stably supply a magnetic disk of a constant quality.

The present invention has been proposed in view of the above-mentioned conventional circumstances, and the characteristics of the individual magnetic heads at any position on the magnetic disk with respect to the magnetic disk having the unevenness indicating the servo signal. Without being affected by
An object of the present invention is to provide a magnetizing device and a magnetizing method capable of always performing optimum magnetizing.

[0012]

A magnetic disk magnetizing apparatus according to the present invention completed to achieve the above object is a magnetic disk magnetizing apparatus having a concavo-convex indicating a servo signal. Based on the magnetic head that magnetizes the disk and reproduces the magnetized signal, and based on the recording current supplied to the magnetic head when magnetizing the magnetic disk and the signal reproduced by the magnetic head, An analysis processing unit that analyzes the value of the recording current most suitable for magnetization is provided.

When a magnetic disk is magnetized using such a magnetic disk magnetizing device, a magnetic head is used to
Based on the recording current supplied to the magnetic head when the magnetic disk is magnetized, and the signal reproduced by the magnetic head is reproduced by the analysis processing unit. Then, the optimum value of the recording current for magnetizing the magnetic disk is analyzed. After that, the magnetic disk is magnetized again by the magnetic head based on the optimum recording current value for magnetizing the magnetic disk analyzed by the analysis processing unit. As a result, the servo signal is written uniformly over the entire magnetic disk without causing variations in the magnetized state of the magnetic disk.

On the other hand, in the magnetic disk magnetizing method according to the present invention, a magnetic disk having concave and convex portions showing a servo signal is magnetized so that the concave portion and the convex portion have different magnetization directions, and the servo signal is magnetized. The optimum value of the recording current for magnetization is measured at a plurality of positions in the radial direction of the magnetic disk, and the optimum position of the magnetic disk in the radial direction and the optimum recording current are measured from the above measurement results. It is characterized in that the magnetic disk is magnetized by changing the recording current depending on the radial position of the magnetic disk based on the calculated result.

Here, the optimum value of the recording current for magnetization is measured, for example, by repeatedly magnetizing the magnetic disk and reproducing the servo signal, and when the reproduced servo signal becomes optimum. The value of the recording current is set to the optimum value of the recording current for magnetization. Further, the magnetic disk is magnetized, for example, by magnetizing both the concave portion and the convex portion in the same direction by a large recording current and then magnetizing only the convex portion in the opposite direction by a small recording current.

In such a magnetic disk magnetizing method,
The magnetic disk is magnetized by changing the recording current to an optimum value depending on the position of the magnetic disk in the radial direction, so that there is no variation in the magnetized state of the magnetic disk. Is written uniformly over the entire area.

[0017]

Embodiments of the present invention will be described below in detail with reference to the drawings. It should be noted that the embodiments described below are suitable specific examples of the present invention, and therefore various technically preferable limitations are given, but the scope of the present invention particularly limits the present invention in the following description. Unless otherwise stated, the present invention is not limited to these modes.

First, in the present embodiment, a magnetic disk which is magnetized in order to magnetically write a servo signal will be described.

As shown in FIG. 1, a magnetic disk to be magnetized is a disk-shaped magnetic disk 1 having a magnetic layer formed on a substrate made of a non-magnetic material such as plastic or glass. Has a servo zone 60, which is an area in which is written, and a data zone 70, which is an area in which normal data is recorded. Here, a plurality of servo zones 60 and data zones 70 are radially formed at regular intervals from the center of the magnetic disk 1 so as to alternate with each other in the circumferential direction M2 of the magnetic disk 1.

Here, each servo zone 60 is, for example,
As shown in FIG. 2, a burst portion 61 in which a burst signal used for automatic gain control or the like is recorded, an address portion 62 in which track position information indicating a track position in the radial direction M1 of the magnetic disk 1 is recorded, and A fine pattern section 63, etc., in which a signal for tracking control is recorded is provided, while each data zone 70 is provided.
Includes a data track portion 71 on which normal data is recorded. That is, in the magnetic disk 1, a burst portion 61, an address portion 62, a fine pattern portion 63, and a data track portion 71 are sequentially formed in the track direction M2 for each track. In addition, the servo zone 6
0 indicates a burst section 61 and an address section 62 as necessary.
Also, it goes without saying that it may have a portion other than the fine pattern portion 63.

Then, on the surface of the substrate of the magnetic disk 1, the burst portion 61, the address portion 62, the fine pattern portion 63 and the data track portion 64 are provided so as to correspond to each other.
The convex portion 1a and the concave portion 1b are formed. That is, as shown in FIG. 3, which is a cross-sectional view of the magnetic disk 1, the magnetic disk 1 includes a substrate 2 and a magnetic layer 3 formed on the substrate 2.
On the surface of the substrate 2, the convex portion 1 is formed so as to correspond to each signal recorded in the burst portion 61, the address portion 62, the fine pattern portion 63 and the data track portion 71.
a and a concave portion 1b are formed. The magnetic disk 1 may not be composed of only the substrate 2 and the magnetic layer 3 as long as the convex portion 1a and the concave portion 1b are formed, and for example, a protective layer is formed on the surface. It may have been done.

When the magnetic disk 1 is used, servo signals are written in advance in the burst section 61, the address 62 section and the fine pattern section 63.
That is, as shown in FIG. 2, the magnetic signal m1 is magnetized to the burst portion 61, the address portion 62, and the portion corresponding to the convex portion 1a of the fine pattern portion 63, and at the same time, the burst portion 61, the address portion 62, and the fine pattern. In the portion of the portion 63 corresponding to the concave portion 1b, the magnetic signal m2 having a magnetization direction opposite to that of the magnetic signal m1 recorded in the portion corresponding to the convex portion 1a.
Is magnetized.

Next, a magnetizing device for magnetizing the above magnetic disk 1 will be described.

This magnetizing device magnetizes the magnetic disk 1 on which the unevenness indicating the servo signal is formed as described above, and magnetically writes the servo signal. As shown in FIG. A rotation control unit 10 that supports and rotates the magnetic disk 1 to be magnetized, a head operation unit 20 that performs a magnetization process and a reproduction process on the magnetic disk 1, supply of a recording current to the head operation unit 20, and a head. A signal processing unit 30 that processes a reproduction signal reproduced by the operation unit 20, and an analysis processing unit 40 that receives and analyzes data from the signal processing unit 30.
And

The rotation control unit 10 includes a disk rotation unit 11 that supports and rotates the magnetic disk 1, and a rotation controller 12 connected to the disk rotation unit 11. The rotation controller 12 causes the disk rotation unit 11 to rotate.
The rotation of is controlled.

The head operating unit 20 for performing the magnetizing process and reproducing process on the magnetic disk 1 supported and rotated by the rotation control unit 10 is a magnetic head for magnetizing and reproducing the magnetic disk 1. 21 and the magnetic head 2
A head operation stage 22 to which 1 is attached and fixed, and a stage controller 23 that controls the operation of the head operation stage 22 are provided.

The operation of the head operation stage 22 is controlled by a signal from the stage controller 23. The magnetic head 21 mounted and fixed to the head operating stage 22 moves in the radial direction M1 of the magnetic disk 1 as the head operating stage 22 moves. Here, the magnetic head 21 magnetically writes the servo signal to the magnetic disk 1 by the DC recording current supplied from the signal processing unit 30 during the magnetization process. Further, the magnetic head 21 reproduces the servo signal written on the magnetic disk 1 and transmits the reproduced signal to the signal processing unit 30 during the reproducing process. The stage controller 23 is connected to the signal processing unit 30, and the position of the magnetic gap of the magnetic head 21 is
That is, position data indicating the position where magnetization or reproduction is performed is transmitted to the signal processing unit 30 as a value in the radial direction M1 on the magnetic disk 1.

Then, the signal processing section 3 for supplying a recording current to the magnetic head 21 of the head operating section 20 and for processing the reproduced signal reproduced by the magnetic head 21 as described above.
0 is a current generator 31 for generating and supplying a recording current.
A signal amplification circuit 32 for amplifying a signal, a signal processing circuit 33 for processing the signal, and a memory 34 for storing various data and the like. Here, the current generator 31 includes a signal amplification circuit 32 and a signal processing circuit 33.
And the signal amplification circuit 32 is connected to the current generator 3
1, the signal processing circuit 33 and the magnetic head 21, and the signal processing circuit 33 is connected to the current generator 31, the signal amplification circuit 32, the memory 34, and the stage controller 23. It is connected to the circuit 33 and the analysis processing unit 40.

When the magnetic disk 1 is magnetized, the signal processing circuit 33 supplies a signal for instructing the magnitude of the recording current to the current generator 31, and the current generator 31 is supplied.
Generates a recording current based on this signal and supplies it to the signal amplifier circuit 32. The signal amplifier circuit 32 amplifies this recording current and supplies it to the magnetic head 21. At this time, the signal processing circuit 33 stores the magnitude of the recording current instructed to the current generator 31 in the memory 34. On the other hand, the magnetic disk 1
When reproducing the servo signal from the signal amplification circuit 32,
The reproduction signal is received from the magnetic head 21 and the reproduction signal is amplified. Then, the signal processing circuit 33 receives the reproduction signal amplified from the signal amplification circuit 32 via the A / D converter 33a, and detects a servo signal, that is, a fine pattern signal, an address signal, a burst signal, etc. from the reproduction signal. The waveform data of this servo signal is stored in the memory 34. In addition, when the magnetization processing or the reproduction processing is performed on the magnetic disk 1 in this way, the signal processing circuit 3
3 is from the stage controller 23 to A as described above.
The position data of the magnetic head 21 is received via the / D converter 33a, and this position data is also stored in the memory 34.

The analysis processing unit 40 for receiving and analyzing the data from the signal processing unit 30 includes an analysis processing circuit 41 connected to the memory 34 of the signal processing unit 30. Then, the analysis processing circuit 41 stores, from the memory 34, the magnitude of the recording current used for the magnetization, the waveform data of the reproduced servo signal, the position data of the magnetic head 21 during the magnetization processing and the reproduction processing, and the like. Is received, and the optimum recording current for magnetization is analyzed. That is, the analysis processing circuit 41
Calculates the optimum recording current at each position on the magnetic disk 1, and further calculates the relationship between the radial position of the magnetic disk and the optimum recording current from the optimum recording current thus calculated at each position.

Since such a magnetizing device is provided with the analysis processing circuit 41 for calculating the relationship between the radial position of the magnetic disk 1 and the optimum recording current, the radial position of the magnetic disk 1 and the optimum recording current. It is possible to magnetize the magnetic disk by changing the recording current so that the magnitude of the recording current for magnetization becomes optimum based on the relationship with the current. Therefore, in this magnetic disk magnetizing device, it is possible to always perform optimum magnetizing at any position on the magnetic disk 1 without being influenced by the characteristics of each magnetic head.

Next, a method of magnetizing the magnetic disk 1 using the above magnetizing device will be described with reference to the flow charts shown in FIGS.

When magnetizing the magnetic disk 1, as shown in FIG. 5, first, in step ST1, the magnetic disk 1 to be magnetized is mounted and fixed on the upper part of the disk rotating portion 11, and then the rotation controller. A signal is sent from 12 to the disk rotating unit 11 so as to rotate at a constant cycle, and the magnetic disk 1 is rotated at a constant cycle.

Next, in step ST2, the magnetic head 21 is moved to the magnetic disk 1 by the head operating stage 22.
Move to the predetermined track position above. Here, the movement of the magnetic head 21 is performed so that the magnetic head 21 is moved to a track on which a magnetizing process described later has not been performed. At this time, the stage controller 23 uses the position data indicating the position of the magnetic gap of the magnetic head 21 as a value in the radial direction on the magnetic disk 1, to the A / D converter 3
3a to the signal processing circuit 33. Then, the signal processing circuit 33 stores this position data in the memory 34.

Next, in step ST3, a sufficiently large first magnetic field is applied to the rotating magnetic disk 1 by the magnetic head 21, and the concave and convex portions on the track on which the magnetic head 21 is located are projected. Both parts are magnetized in a constant direction. That is, in this step ST3, the signal processing circuit 33 outputs a signal for instructing to supply a recording current of a sufficient magnitude to magnetize both the concave portion and the convex portion of the magnetic disk in a certain direction. To the container 31. Then, based on this signal, a recording current is supplied from the current generator 31 to the signal amplifier circuit 32, and this recording current is amplified by the signal amplifier circuit 32 and then supplied to the magnetic head 21. Then, the magnetic head 21 generates a sufficiently large first magnetic field by the recording current thus supplied, and thereby magnetizes both the concave portion and the convex portion on the track of the magnetic disk 1 in a certain direction. .

Next, in step ST4, a small second magnetic field is applied to the rotating magnetic disk 1 by the magnetic head 21 so that only the convex portion on the track of the magnetic disk 1 is processed in step ST3. Magnetize in the opposite direction to the magnetized direction. That is, this step S
At T4, the signal processing circuit 33 issues a signal for instructing to supply a recording current that flows in the opposite direction to the recording current supplied at step ST3 and that is small enough to magnetize only the convex portions of the magnetic disk. It transmits to the electric current generator 31. Then, a recording current is supplied from the current generator 31 to the signal amplifying circuit 32 based on this signal, the recording current is amplified by the signal amplifying circuit 32, and then the magnetic head 2 is supplied.
1 is supplied. Then, the magnetic head 21 generates a small second magnetic field by the recording current supplied in this way, whereby only the convex portion on the track of the magnetic disk is reversed with respect to the direction magnetized in step ST3. Magnetize in the direction of. At this time, the signal processing circuit 33
Stores the magnitude of the recording current supplied to the magnetic head 21 in the memory 34.

By the above steps ST3 and ST4, the servo signal is magnetically written in the track on which the magnetic head 21 is located.

Next, as step ST5, step S
The servo signal written in T3 and step ST4 is reproduced. That is, in this step ST5, the magnetic head 21 reproduces the signal written in the track and supplies the reproduced signal to the signal amplifier circuit 32. Then, the reproduced signal is amplified by the signal amplifier circuit 32 and then supplied to the signal processing circuit 33 via the A / D converter 33a. Then, the signal processing circuit 33
Detects a servo signal from the reproduced signal, that is, a fine pattern signal, an address signal, a burst signal, etc., and stores the waveform data of such a servo signal in the memory 34.

Next, as step ST6, step S
Based on the magnitude of the recording current supplied when applying the second magnetic field at T4 and the waveform data of the servo signal detected at step 5, the optimum recording current for magnetizing the convex portion on the track is obtained. Parse the value. That is, in this step ST6, the analysis processing circuit 41
Reads from the memory 34 the magnitude of the recording current supplied when the second magnetic field is applied in step ST4 and the waveform data of the servo signal detected in step ST5. The optimum recording current value for magnetizing the convex portion is analyzed. Here, the optimum recording current for magnetization, that is, the optimum recording current is the recording current required to magnetize so that the reproduction output becomes maximum when the servo signal is reproduced after magnetization. is there.

Next, in step ST7, it is determined whether or not the optimum recording current has been analyzed and clarified in step ST6. Then, when the optimum recording current is clarified, the process proceeds to step ST8, and when the optimum recording current is not clarified because of insufficient data for analyzing the optimum recording current, the process returns to step ST3. Then, the above-mentioned processing such as magnetization is repeated. Incidentally, when returning to step ST3 and repeating the above-mentioned processing such as magnetization, the magnitude of the recording current is changed in step ST4 so that new data necessary for analysis of the optimum recording current can be obtained. I do.

Then, in step ST8, it is determined whether the above-described analysis of the optimum recording current is completed at all the measurement points. That is, measurement points for performing the analysis of the optimum recording current are set in advance, and in this step ST8, it is determined whether the analysis of the optimum recording current is completed at all of these measurement points. Then, when the analysis of the optimum recording current is completed at all the measurement points, the process proceeds to step ST9 in FIG. 6, and when the measurement points still remain, the process returns to step ST2 to move the magnetic head 21. Then, the optimum recording current at the remaining measurement points is analyzed. here,
The measurement points are set, for example, at equal intervals in the radial direction from the innermost circumference to the outermost circumference of the magnetic disk 1. In step ST2, the magnetic head 21 is moved inward in the radial direction of the magnetic disk 1. It may be moved from the peripheral side to the outer peripheral side at equal intervals. It should be noted that when such a large number of measurement points are set, there is an advantage that the relationship between the optimum recording current and the radial position of the magnetic disk 1 can be accurately obtained, while when a small number of such measurement points are set, Has the advantage that the measurement of the optimum recording current can be completed in a short time.

Then, as shown in FIG. 6, step ST
9, the optimum recording current at each measurement point obtained by the above processing and the magnetic disk 1 at each measurement point
Then, the relationship between the radial position of the magnetic disk 1 and the optimum recording current is calculated from the radial position of. That is, in step ST9, the analysis processing circuit 41 performs interpolation processing such as spline interpolation or linear interpolation on the optimum recording current at each measurement point and the position in the radial direction of the magnetic disk 1 at that time, and the magnetic recording is performed. A table of optimum recording currents with respect to the radial position of the disk 1 is created. Then, the analysis processing circuit 41 stores the relationship between the optimum recording current thus obtained and the radial position of the magnetic disk 1 in the memory 34.

Next, in step ST10, the magnetic head 21 is moved to the outermost track position of the magnetic disk 1 by the head operating stage 22.

Next, in step ST11, as the first magnetizing process, while supplying a constant recording current to the magnetic head 21, the track position from the outermost track to the innermost track of the rotating magnetic disk 1 is supplied. The magnetic head 21 is moved to the position by the head operating stage 22 to magnetize the magnetic disk 1. Here, in the magnetic head 1,
A sufficiently large recording current is supplied so that both the concave portion and the convex portion of the magnetic disk 1 are magnetized in a fixed direction. That is, in this step S11, the signal processing circuit 33
Sends to the current generator 31 a signal instructing to supply a recording current of a sufficient magnitude to magnetize both the concave portion and the convex portion of the magnetic disk 1 in a fixed direction. And
Based on this signal, a recording current is supplied from the current generator 31 to the signal amplifier circuit 32, and this recording current is amplified by the signal amplifier circuit 32 and then supplied to the magnetic head 21. Then, in this step ST11, the magnetic head 21 moves from the outermost track position of the rotating magnetic disk 1 to the innermost track position of the magnetic disk 1, so that the concave and convex parts of all tracks of the magnetic disk 1 are formed. Both will be magnetized in a fixed direction.

Next, in step ST12, as a second magnetizing process, while supplying a small recording current to the magnetic head 21, the track position from the innermost track to the outermost track of the rotating magnetic disk 1 is moved. Until then, the magnetic head 21 is moved by the head operating stage 22 to magnetize the magnetic disk 1. Here, in the magnetic head 21, the magnetization direction of the convex portion of the magnetic disk 1 is changed to the step ST.
So that it is in the opposite direction to the direction magnetized in 11.
A recording current flowing in the opposite direction to the recording current in step ST11 is supplied. Further, the magnitude of the recording current supplied to the magnetic head 21 in this manner is based on the relationship between the optimum recording current stored in the memory 34 in step ST9 and the radial position of the magnetic disk 1.
It is changed depending on the radial position of the magnetic disk 1 so that the convex portions of are magnetically magnetized.

That is, in this step S12,
The signal processing circuit 33 supplies a recording current that optimally magnetizes only the convex portion of the magnetic disk 1 based on the relationship between the optimum recording current stored in the memory 34 and the radial position of the magnetic disk 1. A signal instructing to do so is transmitted to the current generator 31. Then, based on this signal, a recording current is supplied from the current generator 31 to the signal amplifier circuit 32, and this recording current is amplified by the signal amplifier circuit 32 and then supplied to the magnetic head 21. Then, in this step ST12, the magnetic head 21 moves from the innermost track position of the rotating magnetic disk 1 to the outermost track position, so that the convex portions are optimal for all tracks of the magnetic disk 1. It will be magnetized.

By the above-described first magnetization process and second magnetization process, all the concave portions of the magnetic disk 1 are magnetized in a fixed direction, and all the convex portions of the magnetic disk 1 are
The magnetic field is optimally magnetized in the direction opposite to the concave portion of the magnetic disk 1, and the servo signals are optimally written on all tracks of the magnetic disk 1.

Finally, in step ST13,
The magnetic head 21 is retracted from the magnetic disk 1 by the head operating stage 22, and a signal is sent from the rotation controller 12 to stop the rotation of the disk rotating unit 11 to stop the rotation of the magnetic disk 1.
The magnetic disk is removed from the disk rotating unit 11.

In the above-described magnetizing method, the magnetic disk 1 is magnetized by changing the recording current so that the magnitude of the recording current for magnetizing the magnetic disk 1 is optimized. At any position on the magnetic head 1, optimum magnetization can always be performed without being affected by the characteristics of each magnetic head.

[0050]

As is apparent from the above description, according to the present invention, the magnetic disk having the unevenness indicating the servo signal is affected by the characteristics of the individual magnetic heads at any position on the magnetic disk. It is possible to always carry out optimal magnetization without being forced.

Therefore, according to the present invention, it is possible to stably supply a high-quality magnetic disk in which servo signals are uniformly written over the entire magnetic disk.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of a magnetic disk.

FIG. 2 is an enlarged plan view showing a servo zone of the magnetic disk shown in FIG.

FIG. 3 is a transverse cross-sectional view of the magnetic disk taken along a plane along the line XY in FIG.

FIG. 4 is a block diagram schematically showing a configuration example of a magnetic disk magnetizing device to which the present invention is applied.

FIG. 5 is a flowchart of an example of a magnetic disk magnetizing method to which the present invention is applied.

FIG. 6 is a flowchart of an example of a magnetic disk magnetizing method to which the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 magnetic disk 2 substrate 3 magnetic layer 10 rotation control section 11 disk rotation section 12 rotation controller 20 head operating section 21 magnetic head 22 head operating stage 23 stage controller 30 signal processing section 31 current generator 32 signal amplifying circuit 33 signal processing circuit 34 Memory 40 Analysis processing unit 41 Analysis processing circuit

Claims (4)

[Claims] 1. A magnetizing device for a magnetic disk having concavities and convexities indicating a servo signal, the magnetic head magnetizing the magnetic disk and reproducing the magnetized signal, and the magnetic disk when magnetizing the magnetic disk. A magnetic disk comprising an analysis processing unit for analyzing a value of a recording current most suitable for magnetizing a magnetic disk based on a recording current supplied to the magnetic head and a signal reproduced by the magnetic head. Magnetizing device. 2. When the servo signal is magnetically written by magnetizing a magnetic disk having irregularities indicating a servo signal so that the concave portion and the convex portion have different magnetization directions, The optimum value of the recording current is measured at a plurality of positions in the radial direction of the magnetic disk, and the relationship between the radial position of the magnetic disk and the optimum value of the recording current is calculated from the above measurement results. Based on the above, a method for magnetizing a magnetic disk is characterized in that the magnetic disk is magnetized by changing the recording current depending on the radial position of the magnetic disk. 3. The magnetization of the magnetic disk and the reproduction of the servo signal are repeated, and the value of the recording current when the reproduced servo signal is optimum is defined as the optimum value of the recording current for magnetization. The method for magnetizing a magnetic disk according to claim 2, wherein 4. The magnetization is performed by magnetizing both the concave portion and the convex portion in the same direction with a large recording current, and then magnetizing only the convex portion in the opposite direction with a small recording current. The method for magnetizing a magnetic disk according to claim 2.