JP3731813B2 - Magnetic transfer device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a magnetic transfer apparatus that magnetically transfers the information to a magnetic layer of a magnetic recording medium as a slave medium using a magnetic transfer master carrier having a patterned magnetic layer for transferring information to the magnetic recording medium. It is about.
[0002]
[Prior art]
In general, with the increase in the amount of information, a magnetic recording medium is desired that has a large capacity for recording a large amount of information, is inexpensive, and can read out a necessary portion preferably in a short time and can perform so-called high-speed access. It is rare. 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.
[0003]
As a method for performing this pre-formatting accurately and efficiently, a disk-shaped slave having a disk-shaped master carrier on which a transfer pattern corresponding to information is formed of a magnetic material and a magnetic recording surface that receives the transfer of the transfer pattern is provided. With the medium in close contact, a transfer magnetic field is applied to the master carrier by applying a transfer magnetic field to the master carrier and the slave medium (for example, patterns representing servo signals, address signals, etc.) on the slave medium. A technique for transferring is known. This magnetic transfer system is disclosed in, for example, Japanese Patent Application Laid-Open Nos. 10-40544 and 10-269666.
[0004]
In the above magnetic transfer method, a magnetic carrier is applied in the track direction by arranging magnetic field generating means such as an electromagnet device or a permanent magnet device on one or both sides of a master medium in close contact with one or both sides of a slave medium. On the other hand, 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 slave medium and the master carrier that are in close contact with each other, so that the transfer pattern is magnetized on the slave medium. Magnetic transfer is performed on the recording surface.
[0005]
By 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.
[0006]
[Problems to be solved by the invention]
As a specific magnetic field generator, for example, a magnetic field generator 70 in the initial magnetization apparatus shown in FIG. The magnetic field generator 70 shown in FIG. 7 includes 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. 8A is a side sectional view of the magnetic field generator shown in FIG. 7, and FIG. 8B is an intensity distribution on the surface of the slave medium 2 of the magnetic field generated by the magnetic field generator. As shown in FIG. 8, a magnetic field in a direction perpendicular to the paper surface (that is, a magnetic field in the track direction) is applied to the slave medium 2 by the magnetic field generator 70. 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.
[0007]
Magnetic recording media are required to have a larger capacity and a smaller disk. To realize these, it has become necessary to provide a track area having a smaller diameter on the inner circumference side. It is considered that the track area having a smaller diameter can be formed by extending the above-described substantially uniform area of the magnetic field strength toward the slave center. 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, a magnetic field having a magnetic field strength H greater than the coercive force Hc of the slave medium is applied at the position of the innermost track −rmin ′ in the region T2. 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.
[0008]
The present invention has been made in view of such 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 a magnetic pattern.
[0009]
[Means for Solving the Problems]
The magnetic transfer device of the present invention includes an initial magnetization device that applies an initial DC magnetic field to a disk-shaped slave medium to initially magnetize the magnetic layer of the slave medium in one direction of a concentric track, and the slave medium A direction opposite to the direction of the initial magnetization in a state where the master carrier having a patterned magnetic layer for transferring information to the magnetic layer and the magnetic layer of the slave medium that has been initially magnetized are in close contact with each other. A magnetic transfer device comprising a transfer magnetic field applying device that applies a transfer magnetic field in a direction and magnetically transfers the information to the magnetic layer of the slave medium,
The initial magnetization device and / or the transfer magnetic field application device,
First magnetic field generating means for generating a first magnetic field perpendicular to the length direction of the region in a magnetic field generating region of a predetermined length;
A second magnetic field generating means for generating a second magnetic field adjacent to an extension of one end in the length direction of the magnetic field generating region and having a direction substantially opposite to the first magnetic field;
Holding means for holding the slave medium with respect to the first and second magnetic fields so that directions of the first and second magnetic fields coincide with the track direction;
Rotating means for rotating the slave medium relative to the magnetic field generation region with the center of the slave medium as a rotation center,
The first and second magnetic field generating means and the holding means have a magnetic field of the first magnetic field in a first region extending in the radial direction of the track from the innermost track to the outermost track of the slave medium. The magnetic field strength of the first magnetic field in a second region having a strength required for the initial magnetization and / or transfer and symmetric with respect to the center of the track with respect to the first region of the slave medium Is configured to be less than a predetermined value.
[0010]
“Transfer information” means patterning the magnetization arrangement of the magnetic layer of the slave medium into a pattern corresponding to the information.
[0011]
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.
[0012]
The optimum strength of the magnetic field for transfer is about 0.6 to 1.3 times the coercivity of the magnetic layer of the slave medium.
[0013]
“The size required for the initial magnetization and / or transfer” refers to the optimum intensity. The “predetermined value” refers to a value that is about the coercivity of the magnetic layer of the slave medium when an initial DC magnetic field is applied, and about half the coercivity of the magnetic layer of the slave medium when a transfer magnetic field is applied. .
[0014]
As the magnetic field generating means, an electromagnet device, a permanent magnet device or the like can be used.
[0015]
【The invention's effect】
In addition to the initial magnetization device and / or the first magnetic field generating means for generating the first magnetic field, the magnetic transfer apparatus of the present invention generates a second magnetic field that generates a magnetic field substantially opposite to the first magnetic field. In the first region extending in the radial direction of the track extending from the innermost track to the outermost track of the slave medium by the first and second magnetic field generating units and the holding unit that holds the slave medium. The magnetic field strength is set to a size 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 less than a predetermined value. Therefore, a magnetic field having a desired intensity in a predetermined direction of the track can be applied in the first area, and the intensity of the magnetic field opposite to the predetermined direction in the second area. Suppressing can, in all tracks region spreading outermost track from an innermost track, it is possible to perform good magnetic transfer with reduced disturbance of magnetic pattern.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail.
[0017]
FIG. 1 is a perspective view of a main part of an initial magnetization device for initial magnetization of a slave medium, FIG. 2 is a diagram for explaining a magnetic field applied by the initial magnetization device (transfer magnetic field application device), and FIG. FIG. 4 is an exploded perspective view of the holder shown in FIG. 3, FIG. 5 is an exploded perspective view of the holder shown in FIG. 3, and FIG. 5 is an exploded perspective view of the holder shown in FIG. FIG. 5 is a diagram for explaining a basic process of magnetic transfer.
[0018]
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 side. The slave medium 2 of this embodiment is an upper surface 2b of a disk-shaped substrate. And a magnetic recording medium capable of double-sided recording in which magnetic layers are formed on both sides of the lower surface 2c.
[0019]
The master carriers 3 and 4 are formed in a disk shape, and are composed of substrates 3a and 4a on one surface of which a fine uneven pattern is formed by a magnetic layer, and soft magnetic layers 3b and 4b formed on the substrates 3a and 4a. The soft magnetic layers 3b and 4b are held by the holder 10 from the surface opposite to the information carrying surface on which the soft magnetic layers 3b and 4b are formed, and are 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.
[0020]
The initial magnetization apparatus 1 shown in FIG. 1 includes a support base 5 that supports the slave medium 2 from the lower surface 2c of the slave medium 2, and a track direction arranged on the slave medium 2 set on the support base 5. A first magnetic field generator 40 for generating a first magnetic field in one direction, and a second magnetic field disposed adjacent to the first magnetic field generator 40 in a direction opposite to the direction of the first magnetic field. A second magnetic field generating device 45 that generates the magnetic field of FIG. 4 and rotating means (not shown) that rotates the support 5 in the direction of arrow A about the axis M with respect to the first and second magnetic field generating devices 40 and 45. Consists of.
[0021]
2A is a top view of the first and second magnetic field generators, FIG. 2B is a side view, and FIG. 2C is a magnetic field generated by the first and second magnetic field generators. Is a magnetic field intensity distribution on the surface of the slave medium. 2 (a) and 2 (b), the reference numerals in parentheses and the alternate long and short dash line in FIG. 2 (c) indicate the magnetic field generator and magnetic field strength of the magnetic field applying device for transfer shown in FIG. Etc. are shown.
[0022]
The 1st and 2nd magnetic field generators 40 and 45 of this embodiment are permanent magnet devices comprised combining a permanent magnet, respectively. The first magnetic field generator 40 includes two permanent magnets 40a magnetized in a direction substantially perpendicular to the slave medium upper surface 2b, arranged in parallel at predetermined intervals so that the magnetic poles facing the slave medium surface are different from each other. 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.
[0023]
As shown in FIG. 1, the permanent magnet 40a of the first magnetic field generator 40 is arranged so that the north pole faces the medium surface, and the permanent magnet 40b is arranged so that the south pole faces the medium surface. As shown to (a), the 1st magnetic field (solid line arrow) which goes to the magnet 40b from the magnet 40a is generated in a slave medium surface. 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. A second magnetic field (solid arrow) toward the magnet 45a is generated. The magnetic field strength distribution on the surface of the slave medium of the magnetic field generated by the first and second magnetic field generators 40 and 45 is as shown by a solid line in FIG.
[0024]
The support base 5 supports the slave medium 2 with respect to the first and second magnetic field generators so that the first magnetic field and the second magnetic field are in the track direction.
[0025]
Further, 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. A first magnetic field having a strength more than twice the coercive force Hc of the slave medium is applied to a region T1 extending from the innermost track Trmin to the outermost track Trmax, and the slave is slaved to the region T1. In the region T2 that is symmetric about the center, the first magnetic field strength is configured to be less than Hc.
[0026]
In FIG. 2C, the magnetic field strength distribution when only the first magnetic field generator 40 is provided 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, in the vicinity of the innermost track position (-rmin), there is a portion (hatched area in the figure) where the first magnetic field strength is applied when 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 intensity of the first magnetic field may be less than Hc even at the innermost track position (−rmin) of the region T2 that is symmetric with respect to the center of the first magnetic field application region T1. it can.
[0027]
The transfer magnetic field applying device 11 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, 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 lower surface, and adjacent to the first magnetic field generator 50 A second magnetic field generating device 55 that generates a second magnetic field in a direction opposite to the direction of the first magnetic field, and a holder M that has an axis M with respect to the first and magnetic field generating devices 50 and 55. And a rotating means (not shown) that rotates in the direction of arrow A.
[0028]
The first and second magnetic field generating devices 50 and 55 of the transfer magnetic field applying device 11 are permanent magnet devices each configured by combining 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 magnets 52a and 52b. The second magnetic field generation device 55 includes four permanent magnets 55a, 55b, 57a, and 57b in the same combination as the first magnetic field generation device 50. However, the first magnetic field generation device 50 is generated on the slave medium surface. It arrange | positions so that the 2nd magnetic field opposite to a 1st magnetic field may be generated.
[0029]
As shown in FIG. 3, the permanent magnet 50a of the first magnetic field generator 50 is arranged so that the south pole faces the upper surface of the holder, and the permanent magnet 50b is arranged so that the north pole faces the upper surface of the holder. Is arranged such that the south pole faces the bottom surface of the holder, and the permanent magnet 52b is arranged so that the north pole faces the bottom surface of the holder, and both permanent magnets 50a and 50b are arranged on the holder surface from the magnet 50b toward the magnet 50a. A magnetic field (dotted arrow in FIG. 2) is generated, and the permanent magnets 52a and 52b generate a first magnetic field from the magnet 52b toward the magnet 52a on the holder surface. 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) ). The first magnetic field generated by the first magnetic field generator 55 of the transfer magnetic field applying device 11 with respect to the slave medium is the first magnetic field generated by the first magnetic field generator 45 of the initial magnetization device 1. And in the opposite direction.
[0030]
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, and is one area in the track direction. Then, 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 the innermost track Trmin to the outermost track Trmax, and the region T2 is symmetric about the slave center with respect to the region T1. The first magnetic field strength is configured to be less than Hc / 2.
[0031]
The magnetic field intensity distribution of the magnetic field generated by the first and second magnetic field generators 50 and 55 includes the second magnetic field generator 55 as shown in FIG. 50, the change in the magnetic field strength at the end on the slave center side becomes steep, so that the strength of the first magnetic field can be expressed as Hc even at the innermost track position in the symmetric region with respect to the center of the first magnetic field application region. / 2 or less. As shown in FIG. 2C, the transfer magnetic field is a magnetic field opposite to the initial DC magnetic field.
[0032]
FIG. 4 shows an exploded perspective view of the holder 10 and the inside.
[0033]
A 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 an 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 are A lower holder 8 which is a lower pressure contact member provided with a lower correction member 6 for adsorbing and holding the side master carrier 3 to correct flatness, and an upper correction for adhering and holding the upper master carrier 4 to correct flatness By an upper holder 9 which is an upper pressure contact member provided with a member 7 (same configuration as the lower correction member 6), the lower master carrier 3 and the upper master are pressed on both surfaces of the slave medium 2 by being pressed in a state where the center positions are aligned. The carrier 4 is held in close contact.
[0034]
The lower master carrier 3 and the upper master carrier 4 are held by vacuum suction holding on the lower correction member 6 and the upper correction member 7 on the surface opposite to the transfer information carrying surface. 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.
[0035]
The lower correction member 6 (same for the upper correction member 7) is provided in a disk shape corresponding to the size of the master carrier 3, and the surface has a centerline average surface roughness Ra of about 0.01 to 0.1 μm. It is provided on the suction surface 6a which is flattened in flatness. On the suction surface 6a, about 25 to 100 intake holes 6b having a diameter of about 2 mm 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-sucked, and the flatness of the master carrier 3 is corrected along the suction surface 6a.
[0036]
The lower holder 8 that is the lower pressure contact member and the upper holder 9 that is the upper pressure contact member are disc-shaped and one or both of them are provided so as to be movable in the axial direction, and are opened and closed by an opening / closing mechanism (pressing mechanism, fastening mechanism, etc.) not shown. They operate and are brought into pressure contact with each other at a predetermined pressure. The outer periphery has flanges 8a and 9a, and the upper and lower holders 8 and 9 have the flanges 8a and 9a in contact with each other during the closing operation to keep the inside sealed. 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.
[0037]
Next, a magnetic transfer method using the magnetic transfer apparatus will be described.
[0038]
The slave medium 2 is installed on the support 5 of the initial magnetization 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 Arrange them to be 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.
[0039]
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. It is inserted into the magnetic field generated by 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 around the axis M in the direction of arrow A by a rotating means (not shown). By applying the rotation or more, a transfer magnetic field is applied to the entire track surface.
[0040]
In this way, the 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.
[0041]
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 process of applying a magnetic field in one direction to perform initial DC magnetization of the slave medium, and FIG. 5B shows a transfer magnetic field in close contact with the master carrier and the slave medium in the direction opposite 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.
[0042]
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 in advance to align the magnetization of the recording layer 2c in one direction. Thereafter, as shown in FIG. 5B, the surface on the recording layer 2c side 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 the direction opposite to the initial DC magnetic field Hin is obtained. Magnetic transfer is performed by applying a transfer magnetic field Hdu (that is, opposite to the direction of initial DC magnetization). As a result, as shown in FIG. 5 (c), the recording pattern 2c of the slave medium 2 is transferred and recorded with the magnetization pattern corresponding to the magnetic layer having the concavo-convex pattern of the master carrier 3.
[0043]
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 reversed. Thus, similar information can be magnetically transferred and recorded.
[0044]
The first and second magnetic field generators of the initial magnetizing apparatus are each configured by arranging two permanent magnets in parallel at predetermined intervals so that the polarities are opposite to each other. As shown in FIG. 2, a permanent magnet 41 magnetized in a direction perpendicular to the magnetization of both magnets is generated between the two permanent magnets to generate a magnetic field in the same direction as the magnetic field generated by the two magnets 40a and 40b. You may do it. By providing the permanent magnet 41, a larger magnetic field can be generated.
[0045]
In the above-described embodiment, an apparatus including a permanent magnet has been described as an example of the magnetic field generator, but an electromagnet apparatus may be used.
[0046]
In each of the above embodiments, the slave medium or the holder is rotated with respect to the magnetic field generation device. However, the magnetic field generation device may be rotated.
[0047]
In each of the above embodiments, the surfaces of the slave medium or the adherence body of the slave medium and the master carrier are all arranged perpendicular to the vertical direction, but each surface is held parallel to the vertical direction, It can also be set as the structure which arrange | positions a magnetic field generator so that it may face the surface hold | maintained in parallel with the perpendicular 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 is a diagram for explaining a magnetic field applied by an initial magnetization device (transfer magnetic field application device).
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. 5 is a sectional view showing a basic process of magnetic transfer.
FIG. 6 is a perspective view of main parts of an initial magnetization apparatus according to another embodiment.
FIG. 7 is a perspective view showing an example of a conventional magnetic field generator.
8 is a diagram showing a magnetic field and a magnetic field intensity distribution generated by the magnetic field generator shown in FIG.
9 is a view showing a modification of the magnetic field generator shown in FIG.
[Explanation of symbols]
1 Initial DC magnetic field application device
2 Slave media
3, 4 Master carrier
10 Holder
11 Magnetic field application device for transfer
40 First magnetic field generator in initial magnetizer
45 Second Magnetic Field Generator in Initial Magnetizer
50. First magnetic field generator in transfer magnetic field applying device
55 Second magnetic field generator in transfer magnetic field applying device

Claims (1)

An initial magnetizing device that applies an initial DC magnetic field to a disk-shaped slave medium to initially magnetize the magnetic layer of the slave medium in one direction of concentric tracks, and transfers information to the magnetic layer of the slave medium A magnetic field for transfer is applied in a direction opposite to the direction of the initial magnetization while a master carrier having a patterned magnetic layer on the surface and a magnetic layer of the slave medium that has been initially magnetized are in close contact with each other. A magnetic transfer device comprising a transfer magnetic field applying device for magnetically transferring the information to the magnetic layer of the slave medium,
The initial magnetization device and / or the transfer magnetic field application device,
First magnetic field generating means for generating a first magnetic field perpendicular to the length direction of the region in a magnetic field generating region of a predetermined length;
A second magnetic field generating means for generating a second magnetic field opposite to the first magnetic field adjacent to an extension line of one end in the length direction of the magnetic field generating region;
Holding means for holding the slave medium with respect to the first and second magnetic fields so that directions of the first and second magnetic fields coincide with the track direction;
Rotating means for rotating the slave medium relative to the magnetic field generation region with the center of the slave medium as a rotation center,
The first and second magnetic field generating means and the holding means are arranged such that the center of the slave medium is located on the first magnetic field generating means side, and the track extends from the innermost track to the outermost track of the slave medium. radius at a first region extending in the direction, the magnetic field strength of the first magnetic field was the initial magnetization or the magnitude necessary for transcription, the slave with respect to the first region of the slave medium In the second region symmetric with respect to the center of the medium , the magnetic field strength of the first magnetic field is less than the coercive force of the magnetic layer of the slave medium when the initial DC magnetic field is applied, and when the transfer magnetic field is applied. Is configured to be less than half the coercivity of the magnetic layer of the slave medium .

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