JP2001312819A - Method for magnetic recording on perpendicular magnetic recording medium by using master information carrier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent generation of detection errors for reproduced signals caused by the pulse shift in the reproduced waveform in a preformat recording system which uses a master information carrier as a new technique relating to the preformat recording of a magnetic disk medium. SOLUTION: The method for magnetic recording is carried out by bringing the surface of a master information carrier having an information signal in a shape pattern by arranging a ferromagnetic thin film deposited on the substrate surface into tightly in contact with the surface of a perpendicular magnetic recording medium to apply a magnetic field so as to record the information signal corresponding to the arrangement of the ferromagnetic thin film onto the perpendicular magnetic recording medium as the magnetization information. In this method, the length of a specified ferromagnetic thin film on the master information carrier corresponding to the length between a pair of magnetization transition regions adjacent to each other in the magnetization information recorded onto the perpendicular magnetic recording medium is made smaller than the length between the magnetization transition regions desired as the recorded signals onto the perpendicular magnetic recording medium.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording method in which a master information carrier having specific information based on a shape pattern is used, and its information signal is statically and collectively recorded on a perpendicular magnetic recording medium.

[0002]

2. Description of the Related Art At present, magnetic recording / reproducing apparatuses tend to have a high recording density in order to realize a small size and a large capacity.
In the field of hard disk drives, which are typical magnetic storage devices, devices with surface recording densities exceeding 10 Gbit / in2 have already been commercialized, and furthermore, rapid technological advancements have been made to discuss the practical use of 20 Gbit / in2 Is recognized.

[0003] As a technical background enabling such a high recording density, the improvement of the medium performance, the head-disk interface performance, and the improvement of the linear recording density due to the emergence of a new signal processing system such as a partial response are also significant. Is a factor. However, in recent years, the trend of increasing the track density greatly exceeds the trend of increasing the linear recording density, and is a main factor for improving the areal recording density. This is due to the practical use of a magnetoresistive element type head which is much more excellent in reproduction output performance than a conventional inductive type magnetic head.
At present, the practical use of the magnetoresistive element type head makes it possible to reproduce a track width signal of only a few μm or less with good S / N. On the other hand, it is expected that the track pitch will reach the submicron range in the near future with further improvement in head performance in the future.

In order for a head to accurately scan such a narrow track and reproduce a signal with good S / N, the tracking servo technique of the head plays an important role. With regard to such tracking servo technology, in a current hard disk drive, a tracking servo signal, an address information signal, a reproduction clock signal, and the like are recorded at a constant angular interval in one round of the disk, that is, within 360 degrees in angle. (Hereinafter, referred to as a preformat). By reproducing these signals at regular intervals, the magnetic head can accurately scan the track while confirming and correcting the position of the head.

The above-described tracking servo signal, address information signal, reproduction clock signal, and the like serve as reference signals for the head to accurately scan the track. Required. In a current hard disk drive, after a disk is incorporated in the drive, preformat recording is performed by a magnetic head whose position is strictly controlled using a dedicated servo recording device.

In preformat recording of a servo signal, an address information signal, a reproduction clock signal, and the like by a magnetic head using a dedicated servo recording device as described above,
There were the following issues.

First, recording by a magnetic head is basically line recording based on the relative movement between the head and the medium. Therefore, in the above-described method of performing recording while strictly controlling the position of the magnetic head using a dedicated servo recording device, preformat recording requires a lot of time, and the dedicated servo recording device is considerably expensive. This results in a very high cost.

Second, because of the spread of the recording magnetic field due to the spacing between the head and the medium and the pole shape of the recording head,
There is a point that the magnetization transition at the end of the track on which the preformat recording is performed lacks sharpness. The current tracking servo technology detects the position of the head based on the amount of change in the reproduction output when the head scans off the track. Therefore, the signal track recorded in the preformat is not only excellent in S / N when the head accurately scans the track as in reproducing the data information signal recorded between the servo areas, but also in the head. Is required to have a steep reproduction output change amount when scanning off the track, that is, off-track characteristics.

The above problem is contrary to this requirement, and makes it difficult to realize an accurate tracking servo technique in the sub-micron track recording in the future.

As means for solving the problem of preformat recording by a magnetic head as described above, the present inventors disclosed in Japanese Patent Application Laid-Open No. 10-45544 a ferromagnetic thin film pattern corresponding to an information signal on the surface of a substrate. The main purpose is to transfer the magnetization reversal pattern corresponding to the ferromagnetic thin film pattern on the surface of the master information carrier onto the magnetic recording medium by surface transfer recording by bringing the surface of the master information carrier with the surface formed thereon into contact with the surface of the magnetic recording medium. Proposing preformat technology.

In the configuration disclosed in the publication, the recording magnetic field generated from the ferromagnetic thin film on the surface of the master information carrier magnetized in one direction causes the magnetic recording medium to correspond to the ferromagnetic thin film pattern of the master information carrier. The magnetization reversal pattern is transferred and recorded. That is, by forming a ferromagnetic thin film pattern corresponding to a tracking servo signal, an address information signal, a reproduction clock signal, and the like on the master information carrier surface by photolithography technology or the like,
Information signals corresponding to these can be preformat-recorded on the magnetic recording medium.

The recording by the conventional magnetic head is basically a dynamic linear recording based on the relative movement between the head and the medium. On the other hand, the feature of the above configuration is that the recording is accompanied by the relative movement between the master information carrier and the medium. There is no static surface record. Due to such features, the technology disclosed in the publication can exert the following extremely effective effects on the problems related to the preformat recording described above.

First, because of the surface recording, the time required for preformat recording is much shorter than that of a conventional recording method using a magnetic head. Further, an expensive servo recording device for performing recording while strictly controlling the position of the magnetic head is not required. Therefore, productivity related to preformat recording can be significantly improved, and production cost can be reduced.

Secondly, since static recording does not involve relative movement between the master information carrier and the medium, the master information carrier surface and the magnetic recording medium surface are brought into close contact with each other to reduce the spacing between them during recording. Can be minimized. Furthermore, unlike the recording by the magnetic head, the recording magnetic field does not spread due to the pole shape of the recording head. For this reason, the transition of the magnetization at the end of the track on which the preformat recording is performed has an excellent steepness as compared with the recording by the conventional magnetic head, and more accurate tracking is possible. Here, FIG. 5 shows an example of the configuration of the master information carrier surface disclosed in the publication. FIG. 5 shows, for example, a master information pattern recorded in a preformat area provided at every fixed angle in the circumferential direction of the magnetic disk medium for only 10 tracks in the radial direction of the disk medium (that is, the recording track width direction). It is. For reference, a track portion that becomes a data area on the disk medium after the master information pattern is recorded on the disk medium is indicated by a broken line.

The actual master information carrier surface corresponds to the recording area of the magnetic disk medium on which the master information is to be recorded, at every fixed angle in the circumferential direction of the disk and in the radial direction of the disk medium by all recording tracks. , And a master information pattern as shown in FIG.

As shown in FIG. 5, for example, the master information pattern is formed by sequentially arranging respective areas of a clock signal, a tracking servo signal, an address information signal and the like in the track length direction. This master information pattern is formed by an array of ferromagnetic thin films 3 corresponding to information signals. For example, in FIG. 5, a hatched portion is a portion configured by the ferromagnetic thin film 3.
Although the planar shape of the ferromagnetic thin film 3 is all rectangular in FIG. 5, it is not actually limited to this, and can take various shapes depending on the application.

FIGS. 6 and 7 show a dashed line L shown in FIG.
4 shows a configuration example of a cross section of the master information carrier at L ′.
Note that the dashed line LL 'corresponds to the circumferential direction of the magnetic disk medium, and the horizontal direction of the paper also coincides with the time axis direction of the signal when the signal recorded on the magnetic disk medium is reproduced by the magnetic head. As shown in FIG. 6, the master information carrier may have a configuration in which a pattern shape made of the ferromagnetic thin film 3 is embedded and arranged in a surface layer portion of the non-magnetic substrate 8.
Alternatively, as shown in FIG. 7, a configuration in which the pattern of the ferromagnetic thin film 3 is arranged in a convex shape on the surface of the nonmagnetic substrate 8 may be used. 6 is more excellent.

The preformat recording using the master disk as shown in FIGS. 5 to 7 is applicable not only to a conventional in-plane magnetic disk medium but also to a perpendicular magnetic disk medium which will be responsible for ultra-high density recording in the future. Is also effective, and its application development is expected.

[0019]

SUMMARY OF THE INVENTION Here, Japanese Patent Laid-Open No.
In the preformat technology disclosed in Japanese Patent Application No. 0-45544, a ferromagnetic thin film pattern on the surface of a master information carrier corresponds to a magnetization pattern recorded on a magnetic disk medium. Therefore, for example, the length A of each ferromagnetic thin film pattern or the distance B between each ferromagnetic thin film pattern is set on the surface of the master information carrier illustrated in FIGS.
The ferromagnetic thin film patterns may be arranged in accordance with a desired signal length in a magnetization pattern recorded on the magnetic disk medium, that is, a length between a pair of adjacent magnetization transition regions in the magnetization pattern. However,
According to the study of the present inventors, the length between the magnetization transition regions in the magnetization pattern recorded on the magnetic disk medium is actually the length A of each ferromagnetic thin film pattern, the length between the individual ferromagnetic thin film patterns. It does not exactly match the distance B. For this reason, when the length A of the ferromagnetic thin film pattern or the distance B between the ferromagnetic thin film patterns exactly matches the desired length between the magnetization transition regions on the magnetic recording medium, the actual recorded data is obtained. The length between the magnetization transition regions on the magnetic disk medium differs from the desired length.

As a result, in the reproduced waveform when the recorded magnetic pattern is reproduced by the magnetic head, the reproduced pulse position is shifted from the desired pulse position by a certain time.

In this case, the reproduction pulse shift amount is
If the width is sufficiently smaller than the detection window width of the reproduction signal processing circuit, no problem occurs. However, when the detection window width exceeds the allowable limit, the reproduction signal processing circuit cannot detect the reproduction pulse, and a reproduction signal error occurs.

[0022]

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a more desirable magnetic pattern recorded on a perpendicular magnetic recording medium by using the preformat technique disclosed in Japanese Patent Application Laid-Open No. 10-45544. This realizes a configuration that realizes a length between the magnetization transition regions close to the design value of the above, thereby preventing a reproduction signal error from occurring. In order to realize the above means, the present invention requires the
It has two structural features.

First, in a first configuration of the present invention, a magnetic field is applied by bringing the surface of a master information carrier having information signals into close contact with the surface of a perpendicular magnetic recording medium by a shape pattern formed by an array of ferromagnetic thin films deposited on a substrate surface. A magnetic recording method for recording an information signal corresponding to a ferromagnetic thin film array as magnetization information on a perpendicular magnetic recording medium, comprising: a pair of magnetization transition regions adjacent to each other in the magnetization information recorded on the perpendicular magnetic recording medium. The length of the specific ferromagnetic thin film on the master information carrier corresponding to the gap length is smaller than the length of the magnetization transition region desired as a recording signal on the perpendicular magnetic recording medium.

According to a second configuration of the present invention, the surface of the master information carrier having an information signal is in close contact with the surface of the perpendicular magnetic recording medium by a shape pattern formed by the arrangement of ferromagnetic thin films deposited on the surface of the substrate, and a magnetic field is applied. A magnetic recording method for recording an information signal corresponding to a ferromagnetic thin film array as magnetization information on a perpendicular magnetic recording medium, comprising: a pair of adjacent magnetic transitions in the magnetization information recorded on the perpendicular magnetic recording medium. Corresponding to the inter-region length, the length between a specific pair of ferromagnetic thin films adjacent on the master information carrier,
The length between the magnetization transition regions desired as a recording signal for the perpendicular magnetic recording medium is made larger.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail. First, the outline of the magnetic recording method of the present invention will be described with reference to FIG. FIG. 8 is a cross-sectional view of the perpendicular magnetic disk medium 2 in the circumferential direction. The horizontal direction of the drawing indicates the time axis when a magnetization pattern recorded on the perpendicular magnetic disk medium 2 is reproduced using a magnetic head. It also matches the direction.

First, as shown in FIG. 8A, a perpendicular magnetic disk medium 2 on which an information signal is recorded is prepared. next,
As shown in FIG. 8B, the surface of the master information carrier as shown in FIG. 6 or 7 is brought into close contact with the surface of the perpendicular magnetic disk medium 2, and a magnetic field 9 is applied. FIG. 8 is the same as FIG.
7 shows a configuration example in which the master information carrier having the configuration shown in FIG. 7 is used, but a master information carrier having the configuration shown in FIG. 7 may be used.

By applying a magnetic field 9, a leakage magnetic flux 10 corresponding to the shape pattern of the ferromagnetic thin film 3 is generated on the surface of the master information carrier.
In FIG. 8, a magnetization pattern corresponding to the shape pattern of the ferromagnetic thin film 3 is recorded as shown in FIG.

In FIG. 8C, the unrecorded area corresponding to the portion between the ferromagnetic thin films on the surface of the master information carrier and the area where the magnetization 4 is recorded by the leakage magnetic flux 10 from the ferromagnetic thin film are represented by the magnetization transition. The magnetization patterns are arranged alternately with the regions 6 interposed therebetween. Prior to recording using the master information carrier, if the perpendicular magnetic disk medium 2 has been erased to a neutral point in advance by AC erasure or thermomagnetic erasure, the magnetization as shown in FIG. The pattern will be recorded.

On the other hand, as shown in FIG. 9A, before the perpendicular magnetic disk medium 2 is brought into close contact with the surface of the master information carrier, the perpendicular magnetic disk medium is uniformly DC-erased and the initial magnetization is reduced. By giving 11
As shown in (c), it is possible to record a magnetization pattern in which the magnetization due to the residual initial magnetization 11 and the magnetization recorded by the leakage magnetic flux 10 are alternately arranged via the magnetization transition region 6. At this time, the polarity of the initial magnetization 11 is opposite to the polarity of the applied magnetic field 9. When reproducing a magnetization pattern recorded on a perpendicular magnetic disk medium using a magnetic head, the configuration shown in FIG. 9 can obtain a reproduction signal amplitude about twice as large as that of the configuration shown in FIG.

FIG. 1 is a diagram showing the magnetic recording method of the present invention in more detail. FIG. 1 shows a ferromagnetic thin film pattern and recording when preformat recording is performed on a perpendicular magnetic disk medium 2 using a master information carrier 1. FIG. 3 is a schematic cross-sectional view showing the relationship between the obtained magnetization pattern and the waveform reproduced by the magnetic head of the magnetization pattern. FIG. 1 is a sectional view of the perpendicular magnetic disk medium 2 in the circumferential direction.
The horizontal direction of the paper also coincides with the time axis direction when the magnetization pattern recorded on the perpendicular magnetic disk medium 2 is reproduced using the magnetic head.

For comparison, a configuration example of a conventional magnetic recording method using the preformat technique disclosed in Japanese Patent Application Laid-Open No. 10-45544 is shown in FIG.
It was shown to. FIGS. 1 and 4 show the initial magnetization 1 in advance on the perpendicular magnetic disk medium 2 as shown in FIG.
1 shows a configuration in which 1 is given.

In the conventional example shown in FIG. 4, the length A of the ferromagnetic thin film pattern and the distance B between the ferromagnetic thin film patterns are accurately set to the desired lengths a and b between the magnetization transition regions on the perpendicular magnetic disk medium 2. It is configured to match.

According to the study by the present inventors, when preformat recording is performed on the perpendicular magnetic disk medium 2 in the configuration of FIG. 4, the magnetization transition region 6 in the actually recorded magnetization pattern is located at both ends of the ferromagnetic thin film 3. Instead of being located, it was found that the ferromagnetic thin film 3 was shifted slightly outward from the end.

Therefore, the actual length a ′ between the magnetization transition regions in the portion corresponding to the length A of the ferromagnetic thin film pattern is:
On the contrary, the actual length b ′ between the magnetization transition regions in the portion corresponding to the distance B between the ferromagnetic thin film patterns becomes longer than the desired value a on the perpendicular magnetic disk medium 2. Is shorter than the desired value b.

Accordingly, when the recorded magnetization pattern is reproduced by the magnetic head, the difference between a and a ', between the actual reproduced waveform 5 and the desired reproduced waveform 7, as shown in FIG.
Alternatively, a pulse shift corresponding to the difference between b and b 'occurs. If the amount of the pulse shift exceeds the allowable limit of the detection window width of the reproduction signal processing circuit, the reproduction signal processing circuit cannot detect the reproduction pulse, and a reproduction signal error occurs. On the other hand, in the configuration of the present invention shown in FIG. 1, the magnetization transition region 6 is formed so as to obtain desired lengths a and b between the magnetization transition regions in the magnetization pattern recorded on the perpendicular magnetic disk medium 2. The length A of the ferromagnetic thin film pattern on the master information carrier 1 and the distance B between the ferromagnetic thin film patterns are corrected in advance in consideration of the shift amount from the end of the ferromagnetic thin film 3.

That is, the length A of the ferromagnetic thin film pattern is
On the perpendicular magnetic disk medium 2, the distance B between the ferromagnetic thin film patterns is smaller than the desired inter-magnetization transition area length a on the perpendicular magnetic disk medium 2 by an appropriate correction amount α.
By making the correction amount α larger than the desired length b between the magnetic transition regions above, the desired lengths a and b between the magnetic transition regions in the magnetization reversal pattern recorded on the perpendicular magnetic disk medium 2 are obtained. Thus, a desired reproduced waveform 7 can be obtained.

In the configuration of FIG. 1, an appropriate correction amount α is
For example, by observing the reproduced waveform in the conventional example shown in FIG. 4, the difference between the desired magnetization transition region length a and the actual magnetization transition region length a ', or the desired magnetization transition region length It can be estimated as a known value from the difference between b and the actual length b ′ between the magnetization transition regions. Appropriate correction amount α
Are the magnetic properties and thickness of the ferromagnetic thin film 3, the desired length a and b between the magnetization transition regions, and the perpendicular magnetic disk medium 2
It is necessary to estimate experimentally and empirically as described above according to each embodiment, since it differs depending on the magnetic characteristics and the like.

The ferromagnetic thin film pattern on the surface of the master information carrier can be manufactured by using various known lithography techniques. By the way, in the configuration of FIG. 1, an example of the configuration in which the cross-sectional shape of the ferromagnetic thin film 3 is substantially rectangular has been described. However, depending on such features of the lithography technique,
It is not always necessary to realize a rectangular cross-sectional shape as shown in FIG. FIGS. 2 and 3 show another configuration example of the present invention, in which the cross-sectional shape of the ferromagnetic thin film 3 is substantially trapezoidal. In such a master information carrier, the length A of the ferromagnetic thin film pattern and the length B between the ferromagnetic thin film patterns may be controlled at the outermost surface portion of the master information carrier that faces the perpendicular magnetic disk medium 2.

That is, in FIGS. 2 and 3, in the lower bottom portion of the cross section of the ferromagnetic thin film on the trapezoid, the length A of the ferromagnetic thin film pattern is adjusted by an appropriate correction amount α more than the desired length a between the magnetization transition regions. On the other hand, the effect of the present invention can be obtained by making the distance B between the ferromagnetic thin film patterns larger than the desired length b between the magnetization transition regions by the correction amount α.

In the configuration shown in FIG. 1, there is shown a configuration example in which there is no step between the surface of the ferromagnetic thin film 3 and the surface of the nonmagnetic substrate 8 and the surface is almost flat. However, the configuration of the present invention is not limited to this. The configuration may be such that the surface of the ferromagnetic thin film is depressed by a certain amount with respect to the surface of the non-magnetic substrate as shown in FIG. As shown, the surface of the ferromagnetic thin film may be configured to protrude by a certain amount from the surface of the nonmagnetic substrate.

However, in the configuration shown in FIG. 2, if the amount of depression of the surface of the ferromagnetic thin film with respect to the non-magnetic substrate is larger than a certain amount, a spacing loss occurs during signal recording.
The spacing loss varies depending on the recording density of the signal. In general, when recording a signal whose magnetization transition region length a or b is several μm or less, the above-mentioned dent amount is set to 100%.
It is desirable to set it to nm or less.

In the configuration shown in FIG. 3, when the amount of protrusion of the ferromagnetic thin film surface relative to the surface of the non-magnetic substrate is larger than a predetermined amount, sufficient durability may not be obtained in the master information carrier. From such a viewpoint, in the configuration of FIG. 3, it is desirable that the protrusion amount be 100 nm or less.

In the configuration of the present invention shown in FIGS. 1 to 3, the correction amount α is strictly adjusted so that the desired lengths a and b between the magnetization transition regions on the perpendicular magnetic disk medium 2 are accurately realized. It is not always necessary to control the time. That is, it is only necessary that the amount of pulse shift in the reproduced waveform by the magnetic head can be controlled to be equal to or less than the allowable limit of the detection window width of the reproduced signal processing circuit by the correction amount α. From this viewpoint, it is sufficient that the correction amount α can be controlled to a range in which a certain allowable amount is added to an optimum value that can accurately realize the desired lengths a and b between the magnetization transition regions.

In one embodiment of the present inventors, the ferromagnetic thin film 3 on the master information carrier 1 has a saturation magnetic flux density
According to the results of a study using a 1.6T Co film, the thickness of the ferromagnetic thin film is 0.2 μm to 1.0 μm, the desired magnetization transition region lengths a and b are 0.5 μm to 5.0 μm, and the perpendicular magnetic When the coercive force of the disk medium 2 is in the range of 100 kA / m to 300 kA / m, the correction amount α is appropriately in the range of 0.03 μm to 0.4 μm. With this correction amount α, the pulse shift amount in the reproduction waveform by the magnetic head is reproduced. The detection window width of the signal processing circuit could be kept below the allowable limit.

Although the embodiments of the present invention have been described above, the configuration of the present invention can be applied to various embodiments. For example, in the specification of the present application, the description has been made with a primary focus on application to a magnetic disk medium mounted on a hard disk drive or the like, but the present invention is not limited to this, and a flexible magnetic disk, a magnetic card Also, the present invention can be applied to a magnetic recording medium such as a magnetic tape, and the effects of the invention can be obtained in the same manner as described above.

The information signals recorded on the magnetic recording medium have been described with a focus on preformat signals such as tracking servo signals, address information signals, and reproduction clock signals. The applicable information signal is not limited to the above. For example, it is possible in principle to record various data signals, audio and video signals using the configuration of the present invention. In this case, the method of magnetic recording on the magnetic recording medium using the master information carrier of the present invention enables mass production of soft disk media to be produced and can be provided at low cost.

[0047]

As described above, according to the present invention, a preformat signal such as a servo signal for tracking, an address information signal, a reproduction clock signal and the like is statically batch-recorded on a perpendicular magnetic recording medium using a master information carrier. In the magnetic recording method described above, a desired inter-magnetization transition region length closer to the design value can be realized on the magnetization pattern recorded on the perpendicular magnetic recording medium, thereby providing a configuration that does not cause a reproduction signal error.

As a result, in the preformatting technique by static batch recording which is disclosed in Japanese Patent Application Laid-Open No. 10-45544, it is possible to further promote high performance related to signal quality recorded on a perpendicular magnetic recording medium. It is.

[Brief description of the drawings]

FIG. 1 is a schematic cross-sectional view showing a relationship between a configuration example of a magnetic recording method of the present invention and a waveform reproduced by a magnetic head.

FIG. 2 is a schematic cross-sectional view showing the relationship between a configuration example of the magnetic recording method of the present invention and a waveform reproduced by a magnetic head.

FIG. 3 is a schematic cross-sectional view showing the relationship between a configuration example of the magnetic recording method of the present invention and a waveform reproduced by a magnetic head.

FIG. 4 is a schematic cross-sectional view showing the relationship between a configuration example of a conventional magnetic recording method and a waveform reproduced by a magnetic head.

FIG. 5 is a plan view showing one configuration example of a master information carrier surface used in the magnetic recording method of the present invention.

FIG. 6 is a cross-sectional view showing one configuration example of a cross section of a master information carrier used in the magnetic recording method of the present invention.

FIG. 7 is a sectional view showing one configuration example of a section of a master information carrier used in the magnetic recording method of the present invention.

FIG. 8 is a schematic sectional view showing one configuration example of the magnetic recording method of the present invention.

FIG. 9 is a schematic cross-sectional view showing one configuration example of the magnetic recording method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Master information carrier 2 Perpendicular magnetic disk medium 3 Ferromagnetic thin film 4 Magnetization 5 Reproduction waveform 6 Magnetization transition region 7 Desired reproduction waveform 8 Non-magnetic substrate 9 Applied magnetic field 10 Leakage magnetic flux 11 Initial magnetization

Continued on the front page (72) Inventor Noriyuki Furumura 1006 Kazuma Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Yasuaki Ban 1006 Okadoma Kazuma Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. Inventor Taizo Hamada 1006 Kadoma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Hideyuki Hashi 1006 Kadoma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd.

Claims (3)

[Claims] The present invention relates to a ferromagnetic thin film array, wherein a surface of a master information carrier having an information signal is closely applied to a surface of a perpendicular magnetic recording medium and a magnetic field is applied by a shape pattern based on an array of ferromagnetic thin films deposited on a substrate surface. A magnetic recording method for recording a corresponding information signal as magnetization information on the perpendicular magnetic recording medium, wherein the magnetization information recorded on the perpendicular magnetic recording medium corresponds to a length between a pair of adjacent magnetization transition regions in the magnetization information. A length of the specific ferromagnetic thin film on the master information carrier is smaller than a length between magnetization transition regions desired as a recording signal on the perpendicular magnetic recording medium. 2. A ferromagnetic thin film array, wherein a surface of a master information carrier having information signals according to a shape pattern formed by an array of ferromagnetic thin films deposited on a substrate surface is brought into close contact with a surface of a perpendicular magnetic recording medium and a magnetic field is applied. A magnetic recording method for recording a corresponding information signal as magnetization information on the perpendicular magnetic recording medium, wherein the magnetization information recorded on the perpendicular magnetic recording medium corresponds to a length between a pair of adjacent magnetization transition regions in the magnetization information. The length between a specific pair of ferromagnetic thin films adjacent to each other on the master information carrier is made longer than the length between magnetization transition regions desired as a recording signal to the perpendicular magnetic recording medium. Magnetic recording method. 3. Prior to applying a magnetic field by bringing the surface of the master information carrier into close contact with the surface of the perpendicular magnetic recording medium, it is necessary to perform direct current erasing on the perpendicular magnetic recording medium uniformly and in the opposite polarity to the magnetic field. Characteristic magnetic recording method.