JP2003272143A - Magnetic transfer apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To magnetically transfer a satisfactory magnetic pattern. <P>SOLUTION: A first magnetic field strength necessary for an initial magnetization or a transfer is applied to a region T<SB>1</SB>which is one region in the track direction of a slave medium 2 and ranges from the innermost circumferential track Trmin to the outermost circumferential track Trmax by using a first magnetic field generator 40(50) generating the first magnetic field and a second magnetic field generator 45(55) generating a second magnetic field in the opposite direction to the first magnetic field. Further, an initial direct current magnetic field Hin and a magnetic field Hdu for a transfer are applied to the region T<SB>1</SB>so that the first magnetic field strength in a region T<SB>2</SB>symmetrical with respect to a slave center becomes smaller than a predetermined value. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slave medium using a magnetic transfer master carrier having a patterned magnetic layer for transferring information to a magnetic recording medium. The present invention relates to a magnetic transfer apparatus that magnetically transfers the information to a magnetic layer of a magnetic recording medium. 2. Description of the Related Art In general, in a magnetic recording medium, as the amount of information increases, a large capacity for recording a large amount of information, a low cost, and preferably a required portion can be read out in a short time. A medium capable of high-speed access is desired. As an example of these, high-density magnetic recording media (magnetic disk media) used in hard disk devices and flexible disk devices are known, and in order to realize a large capacity, a magnetic head is scanned accurately over a narrow track width. So-called tracking servo technology plays a major role. In order to perform this tracking servo, a servo signal for tracking, an address information signal, a reproduction clock signal, and the like are recorded in a so-called preformat on the disk at certain intervals. As a method for performing this preformat with high accuracy and efficiency, a disk-shaped master carrier having a transfer pattern corresponding to information formed of a magnetic material and a disk having a magnetic recording surface for receiving the transfer pattern transfer. In a state where the slave medium is in close contact, a transfer magnetic field is applied to the master carrier and the slave medium to transfer the transfer pattern (for example, a pattern representing a servo signal, an address signal, etc.) formed on the master carrier to the slave. A technique for magnetic transfer to a medium is known. This magnetic transfer method is disclosed in, for example, Japanese Patent Laid-Open Nos. 10-40544 and 10-269.
No. 566 and the like. In the above magnetic transfer system, a master carrier is in close contact with one or both sides of a slave medium, and magnetic field generating means such as an electromagnet device or a permanent magnet device is provided on one or both sides of the master carrier to provide a magnetic field in the track direction. The transfer magnetic field generating means is rotated relatively around the center of the track (hereinafter referred to as the transfer center) with respect to the closely attached slave medium and the master carrier while the transfer pattern is applied to the slave. Magnetic transfer is performed on the magnetic recording surface of the medium. Due to this magnetic transfer, a recording track for recording information is formed on the magnetic recording surface of the slave medium, and this slave medium can be used as a magnetic recording medium. The slave medium is preliminarily magnetized in one direction in the track direction (circumferential direction) in advance, and then transferred in a direction opposite to the initial magnetization direction in close contact with the master carrier. A magnetic field is applied to magnetically transfer the transfer pattern. As a specific magnetic field generator, for example, there is a magnetic field generator 70 in the initial magnetization apparatus shown in FIG. The magnetic field generator 70 shown in FIG. 7 has two permanent magnets 70a and 70b magnetized in a direction substantially perpendicular to the surface of the slave medium 2 in parallel at a predetermined interval and facing the surface of the slave medium 2. So that the magnetic fields generated by the two magnets are in the track direction of the slave medium 2 on the surface of the slave medium so that the polarities of the permanent magnets 70a and 70b are different from each other. On the other hand, the magnetic field can be applied to the entire surface of the slave medium 2 by rotating the slave medium 2 one or more times. FIG.
(A) is a sectional side view of the magnetic field generator shown in FIG.
FIG. 4B shows the intensity distribution on the surface of the slave medium 2 of the magnetic field generated by the magnetic field generator 70. FIG.
As shown in FIG. 5, the magnetic field generator 70 applies a magnetic field in a direction perpendicular to the paper surface (that is, a magnetic field in the track direction) to the slave medium 2. As shown in FIG. 8 (b), the magnetic field strength on the surface of the slave medium decreases as it approaches the longitudinal end of the magnet, and sufficient strength cannot be obtained at the end of the magnet. It has to be long enough to generate a region where the magnetic field strength is almost uniform over the width of the region T and the region where the magnetic field strength is almost uniform matches the track region T. In FIG. 8, the magnetic field region in which the initial DC magnetic field has a value more than twice the coercive force Hc of the slave medium magnetic layer is arranged so as to coincide with the track region T. In magnetic recording media, there is a demand for further increase in capacity and disk size. In order to realize these, it has become necessary to provide a track area having a smaller diameter on the inner circumference side. . The smaller track area is
It can be formed by extending the above-described region of substantially uniform magnetic field strength toward the center of the slave. As shown in FIG. 9 (a), by extending one end of the magnet on the slave center side, as shown in FIG. 9 (b), the region where the magnetic field strength is almost uniform is changed from the position of radius rmin to the position of rmin ′. Can be widened to the inner peripheral side. However, the magnetic field generated by the magnetic field generator 70 is also applied to the region T2 that is symmetric with respect to the center of the region T1, particularly the inner track side near the center. For example, in FIG. 9, the innermost track in the region T2−
At the position rmin ′, a magnetic field having a magnetic field strength H larger than the coercive force Hc of the slave medium is applied. In the region T2, this magnetic field is a magnetic field substantially opposite to the direction to be originally applied. If the magnetic field strength in the reverse direction is large, the initial magnetization and the transfer magnetization pattern are disturbed, and finally accurate magnetic transfer cannot be performed. If the magnetization pattern is disturbed, particularly when the transfer information is a servo signal, there is a problem that the tracking function cannot be sufficiently obtained and the reliability is lowered. The present invention has been made in view of the above problems, and is a magnetic transfer apparatus that applies a magnetic field to all track areas by rotating a slave medium with respect to a magnetic field generated in one area of a track. An object of the present invention is to provide a magnetic transfer apparatus capable of transferring an accurate magnetization pattern. A magnetic transfer apparatus according to the present invention applies an initial DC magnetic field to a disk-shaped slave medium to cause magnetization of the magnetic layer of the slave medium in one direction of concentric tracks. An initial magnetization device for initial magnetization, a master carrier having a patterned magnetic layer for transferring information to the magnetic layer of the slave medium on the surface, and the magnetic layer of the initially magnetized slave medium are in close contact with each other A transfer magnetic field applying device that applies a transfer magnetic field in a direction opposite to the direction of the initial magnetization in a state of being transferred, and magnetically transfers the information to the magnetic layer of the slave medium. The first magnetizing device and / or the transfer magnetic field applying device generates a first magnetic field in a magnetic field generating region having a predetermined length and generating a first magnetic field orthogonal to the length direction of the region. Means, A second magnetic field generating means for generating a second magnetic field substantially opposite to the first magnetic field adjacent to an extension of one end in the length direction of the magnetic field generating region; and the slave medium; Holding means for holding the first and second magnetic fields so that the directions of the first and second magnetic fields coincide with the track direction; and the slave medium with the center of the slave medium as the center of rotation. Rotating means for rotating relative to the magnetic field generation region, wherein the first and second magnetic field generation means and the holding means are configured to move the tracks from the innermost track to the outermost track of the slave medium. The magnetic field strength of the first magnetic field in the first region extending in the radial direction is a magnitude required for the initial magnetization and / or transfer, and the center of the track with respect to the first region of the slave medium In In symmetric second region by the magnetic field strength of the first magnetic field is characterized in that it is configured to be less than a predetermined value. “Transfer information” means that the magnetization arrangement of the magnetic layer of the slave medium is patterned into a pattern corresponding to the information. The optimum strength of the initial DC magnetic field is not less than the coercive force of the magnetic layer of the slave medium, preferably not less than 1.2 times, more preferably not less than about twice the coercive force. The optimum strength of the transfer magnetic field is about 0.6 to 1.3 times the coercivity of the magnetic layer of the slave medium. The “size necessary for the initial magnetization and / or transfer” refers to the optimum intensity. Also,
“Predetermined value” means the coercivity of the magnetic layer of the slave medium when applying an initial DC magnetic field, and when applying a magnetic field for transfer.
This value is about half the coercivity of the magnetic layer of the slave medium. As the magnetic field generating means, an electromagnet device,
A permanent magnet device or the like can be used. The magnetic transfer apparatus according to the present invention has a magnetic field substantially opposite to the first magnetic field in addition to the initial magnetizing apparatus and / or the first magnetic field generating means for generating the first magnetic field. The radius of the track extending from the innermost track to the outermost track of the slave medium by the first and second magnetic field generation units and the holding unit that holds the slave medium. The magnetic field strength in the first region extending in the direction is set to a magnitude necessary for initial magnetization and / or transfer, and the magnetic field strength of the first magnetic field in a region symmetric with respect to the center of the track with respect to the first region of the slave medium is predetermined. Therefore, a magnetic field having a desired intensity in a predetermined direction of the track can be applied in the first area, and a predetermined direction in the second area. The strength of the magnetic field in the opposite direction can be suppressed, and good magnetic transfer can be performed while suppressing the disturbance of the magnetization pattern in the entire track region from the innermost track to the outermost track. DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described in detail below. FIG. 1 is a perspective view of an essential part of an initial magnetization apparatus for initial magnetization of a slave medium, FIG. 2 is a diagram for explaining a magnetic field applied by the initial magnetization apparatus (transfer magnetic field application apparatus), and FIG. FIG. 4 is an exploded perspective view of the holder shown in FIG. 3, and FIG. 4 is an exploded perspective view of the holder shown in FIG. 3. FIG. 5 is a diagram for explaining a basic process of magnetic transfer. The slave medium is a disk-shaped magnetic recording medium such as a hard disk or a flexible disk having a magnetic recording layer (magnetic layer) formed on both sides or one surface. The slave medium 2 of this embodiment is a disk-shaped substrate. This is a magnetic recording medium capable of double-sided recording, in which a magnetic layer is formed on each of both the upper surface 2b and the lower surface 2c. The master carriers 3 and 4 are formed in a disk shape, and the substrates 3a and 4a on which one side of the master carriers 3a and 4a is formed with a fine uneven pattern and the soft magnetic layers 3b and 4b formed on the substrates 3a and 4a. The soft magnetic layer 3b,
4b is held by the holder 10 from the surface opposite to the information carrying surface, and is in close contact with the magnetic layer of the slave medium. The master carriers 3 and 4 shown in FIG. 2 have concave and convex patterns on the surface according to information for recording on the magnetic recording layers on the upper surface 2b and the lower surface 2c of the slave medium 2, respectively. Note that there are a case where the master carrier is brought into close contact with each side of the slave medium to perform one-sided sequential transfer, and a case where both sides of the slave medium are brought into close contact with the master carrier for simultaneous double-sided transfer. The initial magnetizing apparatus 1 shown in FIG. 1 is arranged on a support base 5 for supporting the slave medium 2 from the lower surface 2c of the slave medium 2, and on the slave medium 2 set on the support base 5. The first magnetic field generating device 40 for generating the first magnetic field in one direction of the track direction and the first magnetic field generating device 4
A second magnetic field generator 45 that is arranged adjacent to 0 and generates a second magnetic field in a direction opposite to the direction of the first magnetic field.
The support 5 is connected to the first and second magnetic field generators 40.
And 45, rotating means (not shown) for rotating in the direction of arrow A about the axis M. FIG. 2 (a) is a top view of the first and second magnetic field generators, FIG. 2 (b) is a side view, and FIG. 2 (c).
Is the magnetic field strength distribution on the slave medium surface of the magnetic field generated by the first and second magnetic field generators. FIG.
In (a) and (b), the reference numerals in parentheses and the alternate long and short dash line in FIG. 3 (c) indicate the magnetic field generator and magnetic field strength of the transfer magnetic field applying device shown in FIG. It is shown. The first and second magnetic field generators 40 and 45 of this embodiment are permanent magnet devices each composed of a combination of permanent magnets. First magnetic field generator 40
Are arranged at a predetermined interval in parallel so that the magnetic poles facing the slave medium surface are different from each other.
Two permanent magnets 40 magnetized in a direction substantially perpendicular to b
a and 40b. The second magnetic field generation device 45 includes two permanent magnets 45a and 45b in the same combination as the first magnetic field generation device 40, but the first magnetic field generated by the first magnetic field generation device 40 on the slave medium surface. It arrange | positions so that the 2nd magnetic field of reverse direction may be generated. As shown in FIG. 1, the first magnetic field generator 4
The permanent magnet 40a of 0 is such that the N pole faces the medium surface,
The permanent magnet 40b is arranged so that the south pole faces the medium surface, and generates a first magnetic field (solid arrow) from the magnet 40a to the magnet 40b on the slave medium surface as shown in FIG. 2A. . On the other hand, the permanent magnet 45a of the second magnetic field generator 45 is arranged so that the south pole faces the medium surface, and the permanent magnet 45b is arranged so that the north pole faces the medium surface. Magnet 45a
A second magnetic field (solid arrow) toward is generated. Of the magnetic field by the first and second magnetic field generators 40 and 45;
The magnetic field strength distribution on the surface of the slave medium is as shown by the solid line in FIG. The support base 5 holds the slave medium 2 in the first manner.
The second magnetic field generator is supported so that the first magnetic field and the second magnetic field are in the track direction. The support 5 and the first and second magnetic field generators 40 and 45 are arranged so that the center (rotation center) of the slave medium 2 is on the first magnetic field generator side. One region in the direction, which is a region T1 extending from the innermost track Trmin to the outermost track Trmax,
A first magnetic field having a strength two or more times the coercive force Hc of the slave medium is applied, and the first magnetic field strength is less than Hc in a region T2 that is symmetric about the slave center with respect to the region T1. Has been. In FIG. 2C, the magnetic field intensity distribution when only the first magnetic field generator 40 is used is indicated by a dotted line. As indicated by the dotted line, in the case of only the first magnetic field generator 40, the inner circumferential side track of the region T2 that is symmetrical with respect to the center with respect to the region T1 to which a magnetic field of a desired intensity is applied by the magnetic field generator 40, For example, the innermost track position (-
In the vicinity of (rmin), there is a portion (hatched area in the figure) where the first magnetic field strength is applied at Hc or higher. However, since the second magnetic field generator 45 is provided as in the present embodiment, the magnetic field at the end of the first magnetic field generator 40 on the slave center side as shown by the solid line in FIG. Since the change in intensity becomes steep, the innermost track position (−r of the region T2 that is symmetric with respect to the center of the first magnetic field application region T1.
Also in (min), the intensity of the first magnetic field can be less than Hc. The transfer magnetic field applying device 11 shown in FIG. 3 includes a holder 10 that holds the slave medium 2 and the master carriers 3 and 4 in close contact with each other and covers the upper and lower surfaces of the contact body, and the holder 10 10. A first magnetic field generator 50 that generates a first magnetic field in one direction in the track direction, comprising four permanent magnets arranged facing the upper and lower surfaces, and the first magnetic field generator 50 The first arranged adjacent to each other
A second magnetic field generating device 55 for generating a second magnetic field in a direction opposite to the direction of the magnetic field of the magnetic field, and the holder 10 with respect to the first and magnetic field generating devices 50 and 55 in the direction of arrow A with the axis M as the center. It consists of a rotating means (not shown) that rotates. The first and second magnetic field generating devices 50 and 55 of the transfer magnetic field applying device 11 are permanent magnet devices each composed of a combination of permanent magnets. The first magnetic field generator 50 is magnetized in a direction substantially perpendicular to the holder surface, which faces the upper surface of the holder 10 and is arranged in parallel at a predetermined interval so that the magnetic poles facing the slave medium surface are different from each other. The two permanent magnets 50a and 50b, and the permanent magnets 50a and 50b and the holder surface facing the lower surface of the holder 10 that generates a magnetic field in the same direction as the permanent magnets 50a and 50b. The permanent magnet 5
2a and 52b. The second magnetic field generator 55 is
It consists of four permanent magnets 55a, 55b, 57a, 57b in the same combination as the first magnetic field generator 50, but on the slave medium surface, the first magnetic field opposite to the first magnetic field generated by the first magnetic field generator 50 is provided. It arrange | positions so that two magnetic fields may be generated. As shown in FIG. 3, the first magnetic field generator 5
The permanent magnet 50a of 0 is arranged so that the south pole faces the upper surface of the holder, the permanent magnet 50b is arranged so that the north pole faces the upper surface of the holder, and the permanent magnet 52a is permanent so that the south pole faces the lower surface of the holder. The magnet 52b is arranged so that the N pole faces the lower surface of the holder, and both the permanent magnets 50a and 50b generate a first magnetic field (a dotted line arrow in FIG. 2) from the magnet 50b to the magnet 50a on the holder surface. Magnet 52
a and 52b are magnets 52b to 5 on the holder surface.
A first magnetic field toward 2a is generated. On the other hand, the permanent magnet 55a of the second magnetic field generator 55 is arranged so that the N pole faces the upper surface of the holder, the permanent magnet 55b is arranged so that the S pole faces the upper surface of the holder, and the permanent magnet 57a is arranged on the lower surface of the holder. The permanent magnet 57b is arranged so that the S pole faces the upper surface of the holder so that the N pole faces, and a second magnetic field opposite to the first magnetic field on the holder surface (the dotted arrow in FIG. 2A) ). For slave media,
The first magnetic field generated by the first magnetic field generator 55 of the transfer magnetic field applying device 11 is substantially opposite to the first magnetic field generated by the first magnetic field generator 45 of the initial magnetization device 1. The holder 10 and the first and second magnetic field generators 50 and 55 are arranged so that the center (rotation center) of the slave medium 2 is on the first magnetic field generator side. The innermost track T
A first magnetic field having a strength of about the coercive force Hc of the slave medium is applied to a region T1 extending from rmin to the outermost track Trmax, and in the region T2 symmetric about the slave center with respect to the region T1, the first magnetic field is applied. The strength is configured to be less than Hc / 2. The magnetic field strength distribution of the magnetic field generated by the first and second magnetic field generators 50 and 55 is shown in FIG.
As shown in FIG. 3, since the second magnetic field generator 55 is provided, the change in the magnetic field strength at the end on the slave center side of the first magnetic field generator 50 becomes steep. Even at the innermost track position in a region symmetric with respect to the center, the strength of the first magnetic field can be less than Hc / 2. As shown in FIG. 2C, the transfer magnetic field is a magnetic field opposite to the initial DC magnetic field. FIG. 4 shows an exploded perspective view of the holder 10 and the inside. The lower master carrier 3 for transferring information such as servo signals to the magnetic layer on the lower surface 2c of the slave medium 2, and the upper master carrier 4 for transferring information such as servo signals to the magnetic layer on the upper surface 2b of the slave medium 2. However, the lower holder 8 which is the lower pressure contact member provided with the lower correction member 6 for correcting the flatness by adsorbing and holding the lower master carrier 3 and the upper master carrier 4 are adsorbed and held to correct the flatness. Upper straightening member 7
The upper master carrier 3 is pressed against the upper surface of the slave medium 2 by the upper holder 9 which is an upper pressure contact member provided with the same structure as the lower correction member 6.
And the upper master carrier 4 are held in close contact with each other. In the lower master carrier 3 and the upper master carrier 4, the surface opposite to the transfer information carrying surface is the lower correction member 6.
And the upper correction member 7 is vacuum-sucked and held. The lower master carrier 3 and the upper master carrier 4 are arranged at positions other than the portion where the fine concavo-convex pattern is formed in order to enhance the adhesion with the slave medium 2 as necessary, and the suction holes of the correction members 6 and 7 described later. A minute hole is formed through the front and back at a position that does not communicate with the medium, and is provided so as to suck and discharge air between the contact surfaces with the slave medium 2. Lower correction member 6 (same for upper correction member 7)
Is provided in a disk shape corresponding to the size of the master carrier 3, and the surface has a center line average surface roughness Ra of 0.01 to
Suction surface 6 finished flat to a flatness of about 0.1 μm
a is provided. The suction surface 6a has a diameter of about 2 m.
About 25 to 100 intake holes 6b of m or less are opened substantially evenly. Although not shown, the suction hole 6b is sucked by being connected to a vacuum pump through an intake passage led from the inside of the correction member 6 to the outside of the lower pressure contact member 8, and is in close contact with the suction surface 6a. The back surface of the carrier 3 is vacuum-adsorbed,
The flatness of the master carrier 3 is corrected along the suction surface 6a. The lower holder 8 which is a lower pressure contact member and the upper holder 9 which is an upper pressure contact member are disk-shaped and one or both of them are provided so as to be movable in the axial direction, and an opening / closing mechanism (pressing mechanism, fastening mechanism, etc.) not shown. ) To open and close, and are brought into pressure contact with each other at a predetermined pressure. There are flanges 8a and 9a on the outer periphery, and the upper and lower holders 8 and 9 are closed when closed.
The flanges 8a and 9a are in contact with each other to hold the inside in a sealed state. At the center of the lower holder 8, a pin 8 b that engages and positions in the center hole of the slave medium 2 is formed. Next, a magnetic transfer method using this magnetic transfer apparatus will be described. The slave medium 2 is placed on the support 5 of the initial magnetizing apparatus 1 and inserted into the magnetic field generated by the first and second magnetic field generators 40 and 45, and the first and second magnetic fields are slaved. The medium 2 is arranged in the track direction. An initial DC magnetic field is applied to the entire track surface by rotating the support 5, that is, the slave medium 2 around the axis M in the direction of arrow A by one or more rotations by a rotating means (not shown) with respect to the first magnetic field. In order to initially magnetize the magnetic layers on both surfaces 2b and 2c of the slave medium 2 at a time, the magnetic field strength on the upper surface 2b and the lower surface 2c of the slave medium 2 is more than twice the coercive force Hc of the magnetic layer of the slave medium 2. To be. If the magnetic field strength on the lower surface is not sufficient, it is necessary to perform initial magnetization on each side. Next, the master carriers 3 and 4 are brought into close contact with the upper and lower surfaces of the initially magnetized slave medium 2 and accommodated in the holder 10. The holder 10 is placed in the first and second magnetic field application devices 11 for transfer. It is inserted into the magnetic field generated by the magnetic field generators 50 and 55 and arranged so that the first and second magnetic fields are in the track direction of the slave medium 2. The first magnetic field in the transfer magnetic field applying device 11 is substantially opposite to the direction of the initial magnetization of the slave medium, and the holder 10 is moved to the axis M by rotating means (not shown) with respect to the magnetic field.
The transfer magnetic field is applied to the entire surface of the track by making one or more rotations in the direction of arrow A around. In this way, information carried by the concave and convex pattern surfaces of the master carriers 3 and 4 is magnetically transferred and recorded on the slave medium 2. The state of the magnetic transfer will be described in detail. FIG. 5 is a diagram showing a transfer process of the magnetic transfer method described above.
FIG. 5A shows a step of applying a magnetic field in one direction to initial DC magnetization of the slave medium. FIG. 5B shows a transfer magnetic field in which the master carrier and the slave medium are in close contact with each other and in the opposite direction to the initial DC magnetic field. FIG. 2C is a side sectional view showing the state after magnetic transfer. In FIG. 5, only the lower recording layer 2c side of the slave medium 2 is shown and only magnetic transfer to the lower recording layer 2c will be described, but the same applies to the upper recording layer 2b. As shown in FIG. 5A, an initial direct current magnetic field Hin is applied to the slave medium 2 in one direction in the track direction so that the magnetization of the recording layer 2c is aligned in one direction. After that, as shown in FIG. 5B, the recording layer 2c of the slave medium 2
And the soft magnetic layer 3b on the convex surface of the master carrier 3 are brought into close contact with each other, and a transfer magnetic field Hdu in a direction opposite to the initial direct current magnetic field Hin (that is, opposite to the initial direct current magnetization direction) is applied. Magnetic transfer. As a result, as shown in FIG. 5C, the recording medium 2c of the slave medium 2 has a master carrier 3
A magnetized pattern corresponding to the magnetic layer having the uneven pattern is transferred and recorded. Even if the concave / convex pattern of the master carrier 3 is a negative pattern having a concave / convex shape opposite to the positive pattern in FIG. 5, the direction of the initial DC magnetic field Hin and the direction of the transfer magnetic field Hdu are opposite to those described above. Thus, similar information can be magnetically transferred and recorded. The first and second magnetic field generators of the initial magnetizing apparatus are each configured by arranging two permanent magnets parallel to each other at a predetermined interval so that their polarities are opposite to each other. As shown in FIG. 6, a permanent magnet magnetized in a direction perpendicular to the magnetization of both magnets, which generates a magnetic field in the same direction as the magnetic field generated by the two magnets 40a and 40b between the two permanent magnets. 41 may be provided.
By providing the permanent magnet 41, a larger magnetic field can be generated. In the above embodiment, an apparatus having a permanent magnet as an example of the magnetic field generating apparatus has been described as an example. However, an electromagnet apparatus may be used. In each of the above embodiments, the slave medium or the holder is rotated with respect to the magnetic field generator. However, the magnetic field generator may be rotated. In each of the above embodiments, the surfaces of the slave medium or the contact body of the slave medium and the master carrier are all arranged perpendicular to the vertical direction. However, each surface is held parallel to the vertical direction. In addition, the magnetic field generator may be arranged so as to face a surface held in parallel with the vertical direction.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a main part of an initial magnetization apparatus for performing a magnetic transfer method according to a first embodiment. FIG. 2 shows an applied magnetic field by an initial magnetization apparatus (transfer magnetic field application apparatus). FIG. 3 is a perspective view of essential parts of a magnetic field applying device for transfer that performs the magnetic transfer method according to the first embodiment. FIG. 4 is an exploded perspective view of the holder and the inside of the holder. FIG. 6 is a main part perspective view of an initial magnetization apparatus according to another embodiment. FIG. 7 is a perspective view showing an example of a conventional magnetic field generator. FIG. 8 is a magnetic field shown in FIG. FIG. 9 is a diagram showing a magnetic field generated by the generator and a magnetic field strength distribution. FIG. 9 is a diagram showing a modification of the magnetic field generator shown in FIG. 7. DESCRIPTION OF SYMBOLS 1 Initial DC magnetic field applying device 2 Slave medium 3, 4 Holder 11 Transfer magnetic field application device 40 First Second magnetic field generating apparatus of the first magnetic field generator 45 initially magnetized device first magnetic field generator 55 transfer magnetic field applying device in the second magnetic field generator 50 transfer magnetic field applying device in the magnetizing device

Claims (1)

What is claimed is: 1. An initial magnetizing apparatus that applies an initial DC magnetic field to a disk-shaped slave medium to initially magnetize a magnetic layer of the slave medium in one direction of a concentric track; and The direction of the initial magnetization in a state in which the master carrier having a patterned magnetic layer for transferring information to the magnetic layer of the slave medium is in close contact with the magnetic layer of the slave medium that has been initially magnetized. A magnetic field transfer device that applies a magnetic field for transfer in a direction opposite to the magnetic field of the slave medium and magnetically transfers the information to the magnetic layer of the slave medium, the magnetic transfer device comprising: / Or a first magnetic field generating means for generating a first magnetic field perpendicular to the length direction of the magnetic field generating region of a predetermined length in the magnetic field generating region of a predetermined length; and the length of the magnetic field generating region One direction A second magnetic field generating means for generating a second magnetic field substantially opposite to the first magnetic field, and the slave medium with respect to the first and second magnetic fields, Holding means for holding the first and second magnetic field directions so as to coincide with the track direction; and rotating the slave medium relative to the magnetic field generation region with the center of the slave medium as a rotation center. Rotating means for causing the first and second magnetic field generating means and the holding means,
The magnetic field strength of the first magnetic field in the first region extending in the radial direction of the track from the innermost track to the outermost track of the slave medium is the initial magnetization and / or
Alternatively, the magnetic field strength of the first magnetic field is less than a predetermined value in a second area that is necessary for transfer and is symmetric with respect to the center of the track with respect to the first area of the slave medium. A magnetic transfer device, characterized in that it is configured as described above.