JP2006244602A - Magnetic recording and reproducing device and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic recording and reproducing device where tracking precision can be improved by obtaining sufficient precision in positional detection of a magnetic head even in such a high-density area where a track pitch is shorter than 0.25 μm, and to provide a manufacturing method of the device. <P>SOLUTION: The device is provided with a process of previously recording a magnetization bit pattern corresponding to an information signal in a magnetic disk by bringing the magnetic disk into contact with the surface of a master information carrier having a shape pattern of ferromagnetic material corresponding to the information signal. The information signal recorded previously contains a servo signal 7 for tracking, and a magnetization transition area between bits in at least a part of the magnetization bit pattern corresponding to the servo signal 7 for tracking is curved with respect to the reproduction gap of the magnetic head loaded to the magnetic recording and reproducing device. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a magnetic recording / reproducing apparatus mounted with a magnetic disk on which a predetermined information signal is recorded in advance using a master information carrier, and a manufacturing method thereof.

In recent years, magnetic recording / reproducing apparatuses tend to have a higher 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 that have a surface recording density of 100 Gbit / in ² (155 Mbit / mm ² ) have already been commercialized. A rapid technological advance is recognized so that the practical use of in ² (310 Mbit / mm ² ) is discussed.

  The technical background that made it possible to achieve such high recording density is also due to the improvement in medium recording performance, head / disk interface performance, and the increase in linear recording density due to the emergence of new signal processing methods such as partial response. . However, in recent years, the increasing tendency of the track density greatly exceeds the increasing tendency of the linear recording density, which is a main factor for improving the surface recording density. This is based on the contribution from the practical use of a giant magnetoresistive head (GMR head) that is much more excellent in reproduction output performance than conventional induction magnetic heads. Currently, with the practical use of GMR heads, it is possible to satisfactorily reproduce the S / N ratio of track width signals of 0.5 μm or less. As the head performance further improves, the track pitch is expected to become even smaller.

  Now, in order for the head to accurately scan such a narrow track and reproduce the signal S / N ratio satisfactorily, the servo tracking technology of the head plays an important role. In order to perform servo tracking, the current hard disk drive is an area in which a servo signal for tracking, an address information signal, a reproduction synchronization signal, etc. are recorded at regular angular intervals within one round of the disk, that is, 360 degrees. (Hereinafter referred to as “servo track area”), and the magnetic head reproduces the signals of these servo track areas at regular intervals, so that the track can be scanned accurately while checking and correcting the position of the head. (For example, refer nonpatent literature 1).

  The tracking servo signal, the address information signal, the reproduction synchronization signal, and the like are used as reference signals for the head to accurately scan the track. Therefore, accurate positioning accuracy is required at the time of recording. Therefore, in the current hard disk drive, after the disk is incorporated into the drive, the above-described tracking servo signal, address information signal, reproduction synchronization signal, etc. are recorded by a magnetic head whose position is strictly controlled using a dedicated servo recording device. (For example, refer nonpatent literature 2).

  Here, in a recording method using a magnetic head using a dedicated servo recording device, recording using the magnetic head is linear recording based on relative movement between the head and the medium. For this reason, the method of performing signal recording over the entire surface of the magnetic disk while strictly controlling the position of the magnetic head using a dedicated servo recording device requires a very long time, and in addition, produces a hard disk drive. Depending on the number of units, the necessary number of dedicated servo recording devices, which are very expensive equipment, must be prepared. Furthermore, signal recording using a servo recording device must be performed in a clean room with the drive housing open. To install many servo recording devices, the capital investment for installing a clean room increases and the cost increases significantly. Was the cause. In order to avoid such a significant increase in manufacturing cost, a method using a master information carrier has been proposed (see, for example, Patent Document 1 and Patent Document 2).

  In Patent Document 1, the master information carrier is obtained by forming a magnetic part made of a ferromagnetic material in a pattern shape corresponding to an information signal on the surface of a base. In the method proposed in Patent Document 1, the surface of the master information carrier is brought into contact with the surface of a sheet-like or disk-like magnetic recording medium on which a ferromagnetic thin film or a ferromagnetic powder coating layer is formed. Then, by applying a predetermined external magnetic field, a magnetic pattern having a pattern shape corresponding to the information signal formed on the master information carrier is magnetically transferred and recorded on the magnetic recording medium.

  In this method, a magnetic field corresponding to the ferromagnetic thin film pattern of the master information carrier is magnetically transferred and recorded on the magnetic recording medium by a recording magnetic field generated from the ferromagnetic thin film on the surface of the master information carrier magnetized in one direction. It will be. That is, by forming a ferromagnetic thin film pattern corresponding to a tracking servo signal, an address information signal, a reproduction synchronization signal, etc. on the surface of the master information carrier by a photolithography technique or the like, these servo track areas are formed on the magnetic recording medium. A signal can be recorded as magnetization information.

  The conventional method of recording with a magnetic head using a dedicated servo recording device is dynamic linear recording based on relative movement between the head and the medium, whereas recording by the method described in Patent Document 1 This is a static surface recording that does not involve relative movement between the master information carrier and the medium. Therefore, since it is the collective surface recording, the time required for signal recording in the servo track area is very short as compared with the recording method using the conventional magnetic head. In addition, an expensive servo recording apparatus for performing recording while strictly controlling the position of the magnetic head is unnecessary, and a vast clean room for installing the servo head is also unnecessary. For this reason, the productivity in signal recording is greatly improved, and the extremely effective effect of reducing the production cost can be exhibited.

  Further, since the method of Patent Document 1 is a method of magnetic transfer recording using shape information as magnetization information, various patterns that cannot be recorded by a magnetic head can be recorded. That is, with a magnetic head, a signal having a track width different from the recording track width inherent to the magnetic head cannot be recorded, and the magnetic head is magnetized in a direction inclined with respect to the recording gap or reproducing gap of the magnetic head. It is also impossible to record a magnetization pattern having a transition region. On the other hand, in the method of Patent Document 1, since a shape pattern made of a ferromagnetic material can be freely designed, even a magnetization pattern that cannot be recorded by a magnetic head can be recorded easily.

On the other hand, in the conventional method, for example, the method described in Non-Patent Document 2, the tracking servo signal recorded by the magnetic head using a dedicated servo recording device is finite in the radial direction of the magnetic disk. Recording track width (generally, the recording track width determined by the magnetic pole width of the magnetic head), and the tracking servo signal is reproduced as the magnetic head is displaced in the radial direction of the magnetic disk. While tracking control is performed by detecting a change in reproduction signal amplitude due to a decrease in track width, according to the method of Patent Document 2, by using the method of Patent Document 1, a magnetic disk is used. Depending on the application of various signals to be recorded, it is possible to record a magnetization pattern that cannot be recorded by a magnetic head and improve the target performance of each signal. That. For example, by using a tracking servo signal pattern having a magnetization transition region in a direction inclined with respect to the reproducing gap of the magnetic head, tracking can be performed by detecting a phase change of a signal accompanying a radial displacement of the magnetic disk. It becomes possible. The method using phase detection described above is less susceptible to disturbance noise than the conventional method using amplitude detection, and can improve the tracking performance.
JP 10-40544 A JP-A-11-144218 Yamaguchi: High-precision servo technology for magnetic disk drives, Journal of Japan Society of Applied Magnetics, Vol. 20, no. 3, pp771 (1996) Uematsu, et al .: Mechanics and servos, current status and prospects of HDI technology, Japan Society of Applied Magnetics, 93rd Research Material, 93-5, pp35 (1996)

  However, in recent years, a tracking servo signal by amplitude detection recorded by the conventional method described in Non-Patent Document 2 or the magnetic transfer method proposed in Patent Document 1 is used in a high-density region where the track pitch is less than 0.25 μm. Furthermore, even with the performance of the tracking servo signal by phase detection recorded by the magnetic transfer recording method proposed in Patent Document 2, the position detection accuracy of the magnetic head is reaching the limit, and sufficient tracking performance is obtained. It was found that sometimes it was not possible. This suggests that the performance corresponding to the increase in the storage capacity may not be obtained with respect to the speed of the hard disk drive such as the access time.

  In order to solve the above problems, it is indispensable to further improve the quality of the tracking servo signal. For this reason, a novel tracking servo signal and its recording not disclosed in the conventional tracking servo signal recording method described in Non-Patent Document 2 or the magnetic transfer method proposed in Patent Document 1 or Patent Document 2 are disclosed. Technology is desired.

  The present invention has been made to solve the above-described problems, and can provide sufficient magnetic head position detection accuracy even in a high-density region where the track pitch is less than 0.25 μm, thereby improving tracking accuracy. An object of the present invention is to provide a magnetic recording / reproducing apparatus and a method for manufacturing the same.

  In order to achieve this object, a magnetic recording / reproducing apparatus of the present invention is a magnetic recording / reproducing apparatus equipped with a magnetic disk in which a magnetization bit pattern corresponding to an information signal is recorded in advance. The magnetization transition region between bits in at least a part of the magnetization bit pattern corresponding to the tracking servo signal that contains the tracking servo signal is curved with respect to the reproduction gap of the magnetic head mounted on the magnetic recording / reproducing apparatus. And a means for detecting a change in the reproduction signal amplitude of the tracking servo signal accompanying the displacement of the magnetic head in the radial direction of the magnetic disk and controlling the tracking of the magnetic head. is doing. The tracking servo signal has a finite recording track width in the radial direction of the magnetic disk, and the reproduction track width of the tracking servo signal by the magnetic head when the magnetic head is displaced in the radial direction of the magnetic disk. And a means for performing tracking control of the magnetic head by detecting a change in the reproduction signal amplitude of the tracking servo signal due to a change in the reproduction servo signal and a change in the reproduction azimuth loss of the tracking servo signal.

  With these configurations, the tracking servo signal has a finite recording track width in the radial direction of the magnetic disk, and the reproduction track of the tracking servo signal as the magnetic head is displaced in the radial direction of the magnetic disk. A change in the playback signal amplitude due to the decrease in width and a change in the playback signal amplitude due to the playback azimuth loss of the tracking servo signal, making it possible to perform tracking control by amplitude detection using both of these actions, The tracking servo signal dynamic range is larger than that of a magnetic recording / reproducing device using a conventional method that performs tracking control by detecting only the change in the reproduction signal amplitude due to a decrease in the reproduction track width of the tracking servo signal. Tracking with better signal quality It is possible to realize a magnetic recording and reproducing apparatus servo signal is obtained.

  Furthermore, in order to achieve the above-described object, the magnetic recording / reproducing apparatus of the present invention is a magnetic recording / reproducing apparatus equipped with a magnetic disk in which a magnetization bit pattern corresponding to an information signal is recorded in advance. The information signal includes a tracking servo signal, and at least a part of the magnetization bit pattern corresponding to the tracking servo signal is opposite to the width direction of the reproducing gap of the magnetic head mounted on the magnetic recording / reproducing apparatus. A plurality of curved magnetization transition regions are arranged in the circumferential direction of the magnetic disk, and the magnetic head detects a phase change between the magnetization transition regions when the magnetic head is displaced in the radial direction of the magnetic disk. It has the structure provided with the means to perform tracking control. The magnetic recording / reproducing apparatus of the present invention is a magnetic recording / reproducing apparatus equipped with a magnetic disk in which a magnetization bit pattern corresponding to an information signal is recorded in advance, and the pre-recorded information signal contains a tracking servo signal. In addition, at least a part of the magnetization bit pattern corresponding to the tracking servo signal has a pair of magnetization transition regions that are curved in opposite directions to the width direction of the reproduction gap of the magnetic head mounted on the magnetic recording / reproducing apparatus. The tracking servo signal has a finite recording track width in the radial direction of the magnetic disk, and the magnetic head is displaced in the radial direction of the magnetic disk. Change of track width of tracking servo signal by magnetic head and playback of tracking servo signal The phase change between the magnetic transition tracking region and the magnetic head tracking control by detecting the change in the reproduction signal amplitude of the tracking servo signal due to the change in zimuth loss and the magnetic head displacement in the radial direction of the magnetic disk. And a means for performing tracking control of the magnetic head. Further, the recording track width of the tracking servo signal in the radial direction of the magnetic disk is not less than 1/4 and not more than 4 times the user data track pitch, and the magnetization transition between bits in at least a part of the magnetization bit pattern The region is curved in an arc shape with respect to the reproduction gap of the magnetic head, and the radius of curvature is 1/8 or more and 4 times or less of the user data track pitch, and at least a part of the magnetization bit pattern The magnetization transition region between the bits in the magnetic head is curved in an elliptical arc shape having a major axis or a minor axis in the width direction of the reproducing gap with respect to the reproducing gap of the magnetic head. The diameter in the width direction and the vertical direction of the elliptical reproduction gap is 0 or more and 8 times or less of the track pitch, and is 0. 025μm or more, in addition to the structure is 2.5μm or less, the magnetic disk, it is also possible to have a configuration which is commutative disk detachable from the magnetic recording and reproducing apparatus.

  With these configurations, it is possible to further include means for performing tracking control by detecting a phase change between the magnetization transition regions accompanying the displacement of the magnetic head in the radial direction of the magnetic disk. In other words, tracking performance is further improved compared to a magnetic recording / reproducing apparatus to which a conventional method is applied by appropriately using or selectively using the tracking control based on the detection of the reproduction signal amplitude and the tracking control based on the phase detection. It is possible to realize the magnetic recording / reproducing apparatus.

  In order to achieve the above-described object, the method of manufacturing the magnetic recording / reproducing apparatus of the present invention includes bringing a magnetic disk into contact with the surface of a master information carrier having a ferromagnetic material shape pattern corresponding to an information signal. A method of manufacturing a magnetic recording / reproducing apparatus equipped with a magnetic disk in which a magnetization bit pattern corresponding to an information signal is recorded in advance. The information signal recorded in advance contains a tracking servo signal and corresponds to the tracking servo signal. A magnetization transition region between bits in at least a part of the magnetization bit pattern to be bent is configured to be curved with respect to a reproduction gap of a magnetic head mounted on the magnetic recording / reproducing apparatus. In addition, at least a part of the magnetization bit pattern corresponding to the tracking servo signal has a pair of magnetization transition regions curved in directions opposite to each other with respect to the width direction of the reproduction gap of the magnetic head mounted on the magnetic recording / reproducing apparatus. A plurality of disks may be arranged in the circumferential direction of the disk.

  With these manufacturing methods, the tracking servo signal has a finite recording track width in the radial direction of the magnetic disk, and the tracking servo signal is reproduced as the magnetic head is displaced in the radial direction of the magnetic disk. Changes in the playback signal amplitude due to the decrease in the track width and changes in the playback signal amplitude due to the playback azimuth loss of the tracking servo signal, making it possible to perform tracking control by amplitude detection using both of these actions Become. Therefore, it is possible to increase the dynamic range of the tracking servo signal compared to the conventional method in which tracking control is performed by detecting only the change in the reproduction signal amplitude due to the decrease in the reproduction track width of the tracking servo signal. Thus, it becomes possible to obtain a servo signal for tracking with better signal quality.

  According to the configuration of the present invention, sufficient magnetic head position detection accuracy can be obtained even in a high-density region where the track pitch is less than 0.25 μm, and a magnetic recording / reproducing apparatus excellent in tracking performance and a method for manufacturing the same Can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
First, the information signal magnetic transfer recording method according to the first embodiment of the present invention will be described. FIG. 1 is a cross-sectional view showing an outline of a recording apparatus for carrying out a magnetic transfer recording method for information signals according to an embodiment of the present invention. In FIG. 1, a hard disk 1 which is a magnetic disk is a donut disk-shaped disk having a center hole 1a. The hard disk 1 is configured by forming a ferromagnetic thin film mainly composed of Co or the like on the surface of a nonmagnetic substrate by a sputtering method.

  A disk-shaped master information carrier 2 is disposed so as to be in contact with the surface of the ferromagnetic thin film of the hard disk 1. The master information carrier 2 is generally larger in diameter than the hard disk 1, and a signal area 2 a is provided on the surface on the side in contact with the hard disk 1. The signal area 2a is formed of a ferromagnetic thin film having a fine array pattern shape corresponding to an information signal to be magnetically transferred and recorded on the hard disk 1.

  The hard disk 1 is held by a disk holder 3. A chuck part 3 a for positioning and holding the hard disk 1 is provided at the tip of the disk holder 3. Further, a suction hole 3 b is provided inside the disk holder 3, the suction hole 3 b communicates with the central hole 1 a of the hard disk 1, and one end is connected to the exhaust duct 4.

  An exhaust device 5 is attached to the end of the exhaust duct 4. When the exhaust device 5 is started, the exhaust duct 4 and the suction hole 3 b of the disc holder 3 are connected to each other between the hard disk 1 and the master information carrier 2. The space between them is in a negative pressure state. As a result, the master information carrier 2 is attracted to the hard disk 1 side and is superposed on the master information carrier 2 with the hard disk 1 positioned.

  At this time, a slight gap groove is formed on the surface of the master information carrier 2 except for the signal area 2a, and air between the hard disk 1 and the master information carrier 2 can be sucked through the gap groove. .

  The magnetizing head 6 is for applying an external magnetic field required for transfer recording from the master information carrier 2 to the hard disk 1. The magnetic thin film pattern corresponding to the information signal formed on the master information carrier 2 is magnetized by the magnetic field applied from the magnetizing head 6, and the magnetic flux corresponding to the magnetic thin film pattern generated from the magnetic thin film pattern corresponds to the shape of the ferromagnetic thin film pattern. The recorded information signal is recorded.

  FIG. 2 is a perspective view showing an example of the configuration of the magnetizing head in the embodiment of the present invention. The magnetizing head 6 shown in FIG. 2 has a magnetic core half 6b made of a ferromagnetic material having a winding 6a and a magnetic core half 6c also made of a ferromagnetic material facing each other. An annular magnetic circuit having a gap 6d is formed.

  By passing an exciting current through the winding 6a, a leakage magnetic flux from the magnetic core half 6c toward the magnetic core half 6b is generated in the gap 6d as indicated by an arrow A. Further, the direction of the leakage magnetic flux generated in the gap 6d can be changed by changing the direction of the applied current. An arrow B indicates the direction of the internal magnetic flux generated in the magnetic core halves 6b and 6c when the leakage magnetic flux in the direction shown in FIG. 2 is generated.

  As the magnetizing head, in addition to the electromagnet type shown in FIG. 2, for example, a magnetic core half formed of a ferromagnetic material is disposed opposite to each other on both sides of a permanent magnet, and an annular magnetic circuit having a gap is provided. It is also possible to use a configuration in which the is formed.

  FIG. 3 is a plan view showing the shape of the gap 6d of the magnetizing head 6 shown in FIG. The gap 6d has the same arc shape as the orbit when the recording / reproducing magnetic head mounted on the hard disk drive performs tracking scanning on the surface of the magnetic disk on the surface facing the master information carrier 2.

  Therefore, the direction of the magnetic field generated in the gap 6d is always perpendicular to the tracking scanning trajectory, and the ferromagnetic thin film of the master information carrier 2 is magnetized in a direction perpendicular to the tracking scanning direction of the recording / reproducing magnetic head in all tracks. Is done. That is, it is magnetized in the same direction as the head gap length direction of the recording / reproducing magnetic head.

  Next, the configuration of the master information carrier 2 will be described. FIG. 4 is a plan view schematically showing an example of the configuration of the master information carrier in the embodiment of the present invention. As shown in FIG. 4, signal regions 2 a are formed substantially radially on one main surface of the master information carrier 2, that is, the surface that contacts the ferromagnetic thin film surface of the hard disk 1. FIG. 5 is a plan view schematically showing a configuration example of an arrangement pattern of information signals formed on a general master information carrier 2, and is an enlarged view of a portion C of the signal region 2a in FIG. ing. In FIG. 5, the horizontal direction corresponds to the radial direction of the hard disk, and the vertical direction corresponds to the circumferential direction of the hard disk.

  In general, a shape pattern of a ferromagnetic material corresponding to an information signal is formed on the surface of the master information carrier 2, and a hatched portion in FIG. 5 is a magnetic portion 2b made of a ferromagnetic material. The shape of the shape pattern formed by the magnetic part 2b on the master information carrier corresponds to the information signal recorded on the hard disk 1, and in the state of overlapping with the hard disk, the position of the shape pattern is the information signal on the hard disk. Corresponds to the position where is recorded. In the configuration example of FIG. 5, the shape pattern corresponding to the information signal is such that the tracking servo signal 7, address information signal 8, clock signal 9, etc. are sequentially moved in the relative movement direction of the magnetic head, that is, the track length direction. It is an arrangement. For reference, a track in the data area 10 where user data is recorded is indicated by a broken line.

  FIG. 6 is a cross-sectional view showing an example of the configuration of the master information carrier in the embodiment of the present invention. The head movement direction of the ferromagnetic thin film formation region of the master information carrier 2 shown in FIG. A part in the vertical direction is shown cut. In FIG. 6, in the master information carrier 2, a ferromagnetic thin film 12 that forms a magnetic part 2b is embedded in a plurality of recesses 11a formed in a main surface 11b of a base 11. The substrate 11 is a disc-shaped substrate formed of a nonmagnetic material such as a Si substrate, a glass substrate, or a plastic substrate. The main surface 11b is a surface on the side where the surface of the hard disk 1 contacts. The recess 11a is formed in a fine array pattern shape corresponding to the information signal.

  Here, in order to obtain good recording characteristics by uniformly adhering the hard disk 1 and the master information carrier 2 using the recording apparatus shown in FIG. 1, the surface 12a of the ferromagnetic thin film 12 is as flat as possible and It is preferable that the main surface 11b of the base body 11 is slightly protruded. For example, the protrusion amount of the ferromagnetic thin film 12 with respect to the major surface 11b of the base body 11 is preferably in the range of 5 nm to 100 nm from the viewpoint of durability of the master information carrier 2.

  As the ferromagnetic thin film 12, not only a hard magnetic material, a semi-hard magnetic material, and a soft magnetic material but also many kinds of magnetic materials can be used. In this case, in order to obtain better signal quality, it is preferable to use a soft magnetic thin film or semi-hard magnetic thin film having a relatively large magnetic permeability and to magnetize it uniformly by exciting it with an external magnetic field during magnetic transfer recording. . For example, Fe, Co, Ni—Fe alloy, Fe—Co alloy, or the like can be used.

  In order to generate a sufficient recording magnetic field regardless of the type of magnetic disk on which the master information signal is recorded, it is better that the saturation magnetic flux density of the magnetic material constituting the ferromagnetic thin film 12 is larger. In particular, for a magnetic disk having a high coercive force exceeding 2,000 oersted (159 kA / m) or a flexible disk having a large magnetic layer thickness, when the saturation magnetic flux density is 0.8 Tesla or less, sufficient recording cannot be performed. There is. For this reason, generally, a magnetic material having a saturation magnetic flux density of 0.8 Tesla or higher, preferably 1.0 Tesla or higher is used.

  The thickness of the ferromagnetic thin film 12 depends on the magnetization reversal length of the recorded information signal, the saturation magnetization, the coercive force, and the film thickness of the magnetic disk magnetic layer. For example, the magnetization reversal length is about 1 μm and the magnetic disk magnetic layer is saturated. When the magnetization is 500 emu / cc (500 kA / m), the coercive force is 3000 oersted (239 kA / m), and the thickness is about 20 nm, the thickness may be about 50 nm to 500 nm.

  Further, in such a magnetic transfer recording method, in order to obtain a good recording signal quality, a magnetic disk such as a hard disk is uniformly DC erased in the circumferential direction prior to magnetic transfer recording using a master information carrier. It is desirable to keep it.

  Here, the DC erasure will be described prior to the description of the procedure for recording on the hard disk. FIG. 7 is a perspective view schematically showing the principle of the DC erasing process of the hard disk in the embodiment of the present invention. FIG. 8 is a perspective view schematically showing the state of the hard disk that has been DC erased in the process of FIG. In the process shown in FIG. 7, in a state where the magnetizing head 6 is brought close to the hard disk 1, the central axis of the hard disk 1 is rotated in parallel with the hard disk. As a result, as indicated by an arrow in FIG. 8, the hard disk is previously magnetized in one direction (that is, DC erased).

  Next, a procedure for recording an information signal corresponding to the shape pattern formed on the master information carrier 2 on the hard disk will be described. As shown in FIG. 1, the exhaust device 5 is started with the master information carrier 2 positioned and superimposed on the hard disk 1. Thus, the master information carrier 2 is sucked through the central hole 1a of the hard disk 1, and the surface of the master information carrier 2 on which the ferromagnetic thin film 12 is formed and the hard disk 1 are overlapped so as to be in close contact with each other.

  FIG. 9 is a perspective view showing a state where an information signal is magnetically transferred and recorded on the hard disk in the embodiment of the present invention. The magnetic field applied by the magnetizing head 6 has a polarity opposite to that of the initial magnetization. In this state, the magnetizing head 6 is rotated in parallel with the master information carrier 2 with the center of the hard disk 1 held by the disk holder 3 as the center of rotation. A DC excitation magnetic field is applied to the master information carrier 2 while continuing this rotation. As a result, the ferromagnetic thin film 12 of the master information carrier 2 is magnetized and corresponds to the pattern shape of the magnetic part by the ferromagnetic thin film 12 in the predetermined information signal recording area 1b of the hard disk 1 superimposed on the master information carrier 2. An information signal is recorded. FIG. 10 is a perspective view schematically showing the state of the hard disk on which the information signal is recorded by the process shown in FIG. The arrows shown in FIG. 10 indicate the direction of magnetization remaining outside the information signal recording area 1 b of the hard disk 1.

  FIG. 11 is a cross-sectional view for schematically explaining the details of the magnetization state when the information signal is magnetically transferred and recorded on the hard disk by the process shown in FIG. As shown in FIG. 11, with the master information carrier 2 in close contact with the hard disk 1, a magnetic field is applied to the master information carrier 2 from the outside to magnetize the ferromagnetic thin film 12. As a result, an information signal is recorded on the magnetic recording layer 1 c made of a ferromagnetic thin film of the hard disk 1.

  That is, by using a master information carrier 2 formed by forming a ferromagnetic thin film 12 in a predetermined pattern shape on a nonmagnetic substrate 11, a digital information signal is magnetically transferred and recorded on a hard disk 1 which is a magnetic recording medium. be able to.

  FIG. 12 is a cross-sectional view for schematically explaining changes in the magnetization state when information signals are magnetically transferred and recorded on the hard disk in the embodiment of the present invention. Here, a series of processes of the magnetic transfer recording shown in FIGS. 7 to 10 will be described again in detail with reference to the schematic cross-sectional view similar to FIG. 12A shows a DC erasing process of the hard disk 1, FIG. 12B shows an information signal magnetic transfer recording process using the master information carrier 2, and FIG. 12C shows an information signal magnetic transfer recording. The residual magnetization state of the hard disk 1 is shown. Each of the drawings showing each process shows a cross section in the head moving direction, that is, in the track length direction of the information signal. When the magnetic recording medium is a hard disk, the track length direction of the information signal coincides with the disk circumferential direction.

  As shown in FIG. 12A, the magnetic recording layer 1c on the hard disk has a DC erasure magnetization 14 in a certain direction by the DC erasing magnetic field 13 prior to magnetic transfer recording of the information signal using the master information carrier. Uniform DC erasure. Next, as shown in FIG. 12B, the surface of the master information carrier 2 on which the ferromagnetic thin film 12 is formed in the array pattern shape corresponding to the information signal is brought into close contact with the surface of the magnetic recording layer 1c on the hard disk. The ferromagnetic thin film 12 is excited by the DC excitation magnetic field 15. At this time, the polarity of the DC exciting magnetic field 15 is opposite to that of the DC erasing magnetic field 13. As a result, the magnetization 14 on the hard disk 1 is reversed by the leakage magnetic flux 16 only in the portion between the adjacent ferromagnetic thin films 12. As a result, after removing the master information carrier 2, a pattern of magnetization 14 corresponding to the array pattern shape of the ferromagnetic thin film 12 formed on the master information carrier 2 can be recorded on the hard disk 1.

  Now, the hard disk 1 in which a signal is recorded in the servo track area by the procedure as described above is mounted in the housing of the hard disk drive and used as it is as a magnetic recording medium having a signal that can be tracked in advance. In addition to the above-described configuration, it is of course possible to add a new information signal such as a servo signal using a magnetic head if necessary.

  Next, an example of an information signal array pattern formed on a general master information carrier shown in FIG. 5 will be described with respect to a method of performing tracking control of a magnetic head in a hard disk drive using a recorded tracking servo signal. See once again and explain below.

  FIG. 5 is a plan view showing a configuration example of the shape pattern of the magnetic part 2b formed on the surface of the master information carrier. The information signal pattern recorded on the hard disk as the magnetization information by the procedure described above is magnetic This corresponds to the shape pattern of the portion 2b. Therefore, FIG. 5 shows the shape pattern of the surface of the master information carrier, and at the same time, it can be understood that it shows a magnetization bit pattern recorded as an information signal on the hard disk. In FIG. 5, the horizontal direction in the figure corresponds to the radial direction of the hard disk, and the vertical direction corresponds to the circumferential direction of the hard disk, but signals are recorded so that opposite polarity magnetization remains in the circumferential direction in the hatched part and other parts. The boundary is a magnetization transition region. A reproduction gap of a magnetic head mounted on a hard disk drive and reproducing an information signal is configured to be parallel to the magnetization transition region of the magnetization bit pattern. That is, in the region shown in FIG. 5, the width direction of the reproduction gap coincides with the recording track width direction (lateral direction in FIG. 5).

  Of the information signal pattern shown in FIG. 5, the tracking servo signal 7 has a recording track width Tw and is composed of four types of burst signals 7a, 7b, 7c, and 7d that are shifted from each other in the radial direction of the hard disk. Has been. The burst signals 7a and 7b are arranged on the extension of the data track every 1 data track pitch Tp, and the positions of 7a and 7b are shifted by 1 data track pitch. The burst signals 7c and 7d are arranged between adjacent data tracks with a shift of a half data track pitch from the extension of the data track every other data track pitch, and the positions of 7c and 7d are shifted by one data track pitch from each other. is doing.

When reproduced using a magnetic head information signal pattern as described above, results in reproduction track width loss L _w corresponding to the disk radial displacement of the magnetic head, the tracking servo signal 7a, 7b, 7c, 7d of the reproduction output amplitude Are different. That is, by detecting the change in the reproduction output amplitude of 7a, 7b, 7c, 7d accompanying the displacement of the magnetic head in the radial direction of the disk, it is possible to detect the displacement of the magnetic head from the center of a certain data track, i. .

For the sake of simplicity, assuming that the width of the reproducing element of the magnetic head is the same as the recording track width Tw of the tracking servo signal, the magnetic head moving in the center of the data track will either track the tracking servo signal 7a or 7b as a full track. It is possible to reproduce with the width Tw. On the other hand, if the reproduction track width displaced position of the magnetic head from the recording track width center becomes is W, produced reproduction track width loss L _w represented by the following equation (1), L _w min only reproduced output amplitude Decreases. At this time, the position of the magnetic head is displaced by (Tw−W) from the recording track width center.

For example, a magnetic head moving in the center of a data track reproduces the tracking servo signal 7a with a full track width of 1 Tw, then reproduces 7b with a reproduction track width of 0 Tw, 7c with 0.5 Tw, and 7d with a reproduction track width of 0.5 Tw, The reproduction output amplitude ratio of 7a, 7b, 7c, and 7d is 1: 0: 0.5: 0.5. On the other hand, when the position of the magnetic head deviates from the recording track width center, resulting reproduction track width loss L _w represented by equation (1), 7a, 7b, 7c, is reproduced output amplitude ratio of 7d changes. Specifically, the displacement (Tw−W) of the magnetic head from the center of the data track can be obtained from (Equation 1) by comparing the reproduction output amplitudes of 7a and 7b and the reproduction output amplitudes of 7c and 7d. It can be done. The tracking control based on the reproduction output amplitude detection using the reproduction track width loss as described above with reference to FIG. 5 is not limited to the method shown in Patent Document 1 described in the background art, and is not a non-patent document. 1 and Non-Patent Document 2 are also commonly used in the conventional methods.

  However, as already described in the problem to be solved, in recent years, the track pitch has reached a high density region of less than 0.25 μm. It has been found that the position detection accuracy is reaching the limit, and sufficient tracking performance may not be obtained.

  For this reason, the master information carrier according to Embodiment 1 of the present invention has, as one structural example, a shape pattern of a ferromagnetic material corresponding to an information signal as shown in FIG.

  FIG. 13 is a plan view schematically showing an example of the configuration of the information signal array pattern formed on the surface of the master information carrier in Embodiment 1 of the present invention. The information signal pattern to be recorded corresponds to the shape pattern of the magnetic part 2b. Therefore, FIG. 13 shows the shape pattern of the surface of the master information carrier, and at the same time, it can be understood that it shows a magnetization bit pattern recorded as an information signal on the hard disk. In FIG. 13, the horizontal direction corresponds to the radial direction of the hard disk and the vertical direction corresponds to the circumferential direction of the hard disk, but a signal is recorded so that opposite polarity magnetization remains in the circumferential direction between the hatched portion and other portions. The boundary is a magnetization transition region. The width direction of the reproduction gap of the magnetic head mounted on the hard disk drive for reproducing the information signal is configured to coincide with the recording track width direction, that is, the horizontal direction in FIG. 13 in the region shown in FIG.

  In the information signal pattern shown in FIG. 13, the tracking servo signal 7 has the recording track width Tw and is shifted in the radial direction of the hard disk and is positioned in the four kinds of burst signals 7a and 7b, as in FIG. , 7c, 7d. The burst signals 7a and 7b are arranged on the extension of the data track every 1 data track pitch Tp, and the positions of 7a and 7b are shifted by 1 data track pitch. The burst signals 7c and 7d are arranged between adjacent data tracks with a shift of a half data track pitch from the extension of the data track every other data track pitch, and the positions of 7c and 7d are shifted by one data track pitch from each other. is doing.

  On the other hand, the difference from the configuration of FIG. 5 showing an example of the arrangement pattern of information signals formed on a general master information carrier is that the magnetization transition region between bits in the burst signals 7a, 7b, 7c, 7d is magnetic recording. The point is that the magnetic head mounted on the reproducing apparatus is curved with respect to the reproducing gap. That is, at the center of each burst signal in the track width direction, the magnetization transition region is parallel to the reproduction gap, and the angle θ between the magnetization transition region and the reproduction gap is 0 degree. On the other hand, with the displacement from the center in the track width direction, the magnetization transition region is curved, and the angle θ formed by the magnetization transition region and the reproduction gap is increased.

When the information signal pattern as described above is reproduced using a magnetic head, a reproduction azimuth loss L _θ corresponding to the displacement of the magnetic head in the radial direction of the disk is generated together with the reproduction track width loss L _w described above, and the tracking servo signal The reproduction output amplitudes of 7a, 7b, 7c, and 7d are different from each other. That is, by detecting the change in the reproduction output amplitude of 7a, 7b, 7c, 7d accompanying the displacement of the magnetic head in the radial direction of the disk, it is possible to detect the displacement of the magnetic head from the center of a certain data track, i. .

When the reproduction track width by the magnetic head is W, the angle θ between the magnetization transition region and the reproduction gap, and the reproduction signal wavelength are λ, the reproduction azimuth loss L _θ is expressed by the following (formula 2). In the configuration of FIG. 13, the angle θ formed by the magnetization transition region and the reproduction gap is configured to increase with the displacement from the center in the track width direction, so the actual L _θ is the reproduction azimuth loss in the minute track width region ΔW. Is integrated over the track width W.

In this case, playback output amplitude changes due to the disk radial displacement of the magnetic head, since occurs due to both the reproduction track width loss L _w and reproducing azimuth loss L _theta, reproduction track width loss shown in FIG. 5 L _w Compared to the configuration caused solely by the above, it is possible to increase the dynamic range of the tracking servo signal, and it is possible to obtain a tracking servo signal with better signal quality. As a result, even in a high-density region where the track pitch is less than 0.25 μm, it is possible to realize the necessary position detection accuracy of the magnetic head and obtain a sufficient tracking performance.

  Incidentally, since a magnetic head mounted on a hard disk drive generally has a parallel recording gap over the recording track width unique to the magnetic head, a servo signal pattern having such a curved magnetization transition region is recorded. I can't. That is, the configuration of FIG. 13 can be realized only by the magnetic transfer recording using the master information carrier. In FIG. 13, a guard band is provided between the recording tracks in the clock signal 9 and the address information signal 8 by taking advantage of the feature of magnetic transfer recording that a signal pattern that cannot be recorded by such a magnetic head can be recorded. Instead, a configuration is adopted in which the magnetization transition region continuously crosses a plurality of recording tracks in the radial direction of the hard disk. Thus, a signal in which the magnetization transition region continuously traverses a plurality of recording tracks without providing a guard band cannot be recorded by a magnetic head having a finite length recording track width.

  Note that the information signal pattern shown in FIG. 13 is an example, and the configuration and arrangement of the shape information pattern on the master disk are appropriately set according to the configuration, purpose, and use of the information signal recorded on the magnetic disk. It is possible to change.

  For example, in the configuration of FIG. 13, the recording track width Tw of the tracking servo signals 7a, 7b, 7c, and 7d is configured to be substantially equal to the data track pitch Tp, and is arranged every other data track pitch. The configuration of the master information carrier in the magnetic recording / reproducing apparatus of the first embodiment is not limited to the above. According to the experimental study by the present inventors, even when the recording track width Tw of the tracking servo signals 7a, 7b, 7c, 7d is set in the range of 1/4 to 4 times the user data track pitch Tp. The effects as described above can be sufficiently obtained. In this case, the tracking servo signals 7a, 7b, 7c, and 7d may be arranged at intervals of 1/4 to 4 times the user data track pitch Tp in accordance with the recording track width Tw.

  The curved shape of the magnetization transition region may be an arc shape, an elliptical arc shape, or other similar curved shape. According to the experimental study by the present inventors, when the magnetization transition region has an arc shape, the above-described effects are sufficiently obtained when the curvature is in the range of 1/8 to 4 times the user data track pitch. It was. On the other hand, when the magnetization transition region is curved in the shape of an elliptic arc whose major axis or minor axis is the width direction of the reproduction gap of the magnetic head, the diameter of the ellipse reproduction gap in the width direction is 1 of the user data track pitch Tp. The effect was sufficiently obtained in the range of / 4 or more and 8 times or less and the diameter of the elliptical reproduction gap in the direction perpendicular to the width direction was 0.025 μm or more and 2.5 μm or less.

(Embodiment 2)
Next, a master information carrier in a magnetic recording / reproducing apparatus according to another embodiment 2 of the present invention will be described. In the second embodiment of the present invention, the configuration related to FIGS. 1 to 4 and 6 to 12 is the same as the example of the first embodiment. Therefore, in order to avoid duplication, the description is omitted here. The characteristics related to the shape pattern of the ferromagnetic material corresponding to the information signal on the master information carrier will be described. The master information carrier according to the second embodiment of the present invention has, as one configuration example, a shape pattern of a ferromagnetic material corresponding to an information signal as shown in FIG.

  FIG. 14 is a plan view schematically showing an example of the configuration of the arrangement pattern of information signals formed on the surface of the master information carrier in Embodiment 2 of the present invention. The information signal pattern recorded in the pattern corresponds to the shape pattern of the magnetic part 2b. Therefore, FIG. 14 shows the shape pattern on the surface of the master information carrier, and at the same time, it can be understood that it shows the magnetization bit pattern recorded as the information signal on the hard disk. In FIG. 14, the horizontal direction corresponds to the radial direction of the hard disk and the vertical direction corresponds to the circumferential direction of the hard disk, but a signal is recorded so that reverse polarity magnetization remains in the circumferential direction between the hatched portion and other portions. The boundary is a magnetization transition region. The width direction of the reproduction gap of the magnetic head mounted on the hard disk drive for reproducing the information signal is configured to coincide with the recording track width direction, that is, the horizontal direction in FIG. 14 in the region shown in FIG.

  In the information signal pattern shown in FIG. 14, the tracking servo signal 7 has the recording track width Tw and is shifted in the radial direction of the hard disk so as to be positioned in the same manner as in FIG. 5 and FIG. 7a, 7b, 7c, 7d. The burst signals 7a and 7b are arranged on the extension of the data track every 1 data track pitch Tp, and the positions of 7a and 7b are shifted by 1 data track pitch. The burst signals 7c and 7d are arranged between adjacent data tracks with a shift of a half data track pitch from the extension of the data track every other data track pitch, and the positions of 7c and 7d are shifted by one data track pitch from each other. is doing.

  The configuration of FIG. 14 differs from the configuration of FIG. 5 in that the magnetization transition region between bits in the burst signals 7a, 7b, 7c, and 7d is curved with respect to the reproduction gap of the magnetic head mounted on the magnetic recording / reproducing apparatus. It is the point which is comprised as follows. That is, at the center of each burst signal in the track width direction, the magnetization transition region is parallel to the reproduction gap, and the angle θ formed by the magnetization transition region and the reproduction gap is 0 degree. On the other hand, with the displacement from the center in the track width direction, the magnetization transition region is curved, and the angle θ formed by the magnetization transition region and the reproduction gap is increased.

When playing the above-described information signal pattern of the magnetic head, similar to the arrangement of FIG. 13, resulting reproduction azimuth loss L _theta corresponding to the disk radial displacement of the magnetic head with a reproduction track width loss L _w, servo tracking The reproduction output amplitudes of the signals 7a, 7b, 7c, and 7d are different from each other. That is, by detecting the change in the reproduction output amplitude of 7a, 7b, 7c, 7d accompanying the displacement of the magnetic head in the radial direction of the disk, it is possible to detect the displacement of the magnetic head from the center of a certain data track, i. .

Therefore, even in the configuration of FIG. 14, similar to the arrangement of FIG. 13, playback output amplitude changes due to the disk radial displacement of the magnetic head occurs due to both the reproduction track width loss L _w and reproducing azimuth loss L _theta so that as compared with the configuration in which only due to the reproduction track width loss L _w shown in FIG. 5, it is possible to increase the dynamic range of the tracking servo signal to obtain a servo signal for tracking having more excellent signal quality Can do.

  Further, the configuration of FIG. 14 is different from the configuration of FIG. In the configuration of FIG. 14, there are a pair of magnetization transition regions in which the magnetization bit patterns in the burst signals 7a, 7b, 7c, and 7d are curved in directions opposite to each other with respect to the reproduction gap of the magnetic head mounted on the magnetic recording / reproducing apparatus. The configuration is such that a plurality of magnetic disks are arranged in the circumferential direction. By adopting such a configuration, as the magnetic head is displaced in the radial direction of the magnetic disk, a phase between a pair of magnetization transition regions curved in opposite directions with respect to the reproduction gap or a plurality of magnetic transition regions are arranged. The mutual phase changes with respect to the magnetization transition region. For this reason, the configuration of FIG. 14 can further include means for detecting a phase change between the magnetization transition regions accompanying the radial displacement of the magnetic disk and performing tracking control. That is, the tracking control based on the reproduction signal amplitude detection having a large dynamic range and the tracking control based on the phase detection between the magnetization transition regions are used in combination or selected as appropriate, as in the configuration in FIG. Compared with the method of Document 2, it is possible to further improve the tracking performance. Therefore, also in the configuration of FIG. 14, it is possible to realize the necessary position detection accuracy of the magnetic head in a high-density region where the track pitch is less than 0.25 μm, and to obtain sufficient tracking performance.

  Similarly to the configuration of FIG. 13, the configuration of FIG. 14 cannot be recorded using a magnetic head generally mounted on a hard disk device, but can be realized only by magnetic transfer recording using a master information carrier. Is something. Also in FIG. 14, as in the configuration of FIG. 13, the recording of the clock signal 9 and the address information signal 8 is performed by utilizing the feature of magnetic transfer recording that a signal pattern that cannot be recorded by such a magnetic head can be recorded. A configuration is adopted in which no guard band is provided between the tracks, and the magnetization transition region continuously crosses a plurality of recording tracks in the radial direction of the hard disk. Thus, a signal in which the magnetization transition region continuously traverses a plurality of recording tracks without providing a guard band cannot be recorded by a magnetic head having a finite length recording track width.

  Note that the information signal pattern shown in FIG. 14 is an example, and the configuration and arrangement of the shape information pattern on the master disk are appropriately set according to the configuration, purpose, and use of the information signal recorded on the magnetic disk. It is possible to change.

  For example, in the configuration of FIG. 14, the recording track width Tw of the tracking servo signals 7a, 7b, 7c, and 7d is configured to be substantially equal to the data track pitch Tp, and is arranged every other data track pitch. The configuration of the master information carrier in the magnetic recording / reproducing apparatus according to the second embodiment of the invention is not limited to the above. According to the experimental study by the present inventors, even when the recording track width Tw of the tracking servo signals 7a, 7b, 7c, 7d is set in the range of 1/4 to 4 times the user data track pitch Tp. The effects as described above can be sufficiently obtained. In this case, the tracking servo signals 7a, 7b, 7c, and 7d may be arranged at intervals of 1/4 to 4 times the user data track pitch Tp in accordance with the recording track width Tw.

  The curved shape of the magnetization transition region may be an arc shape, an elliptical arc shape, or other similar curved shape. According to the experimental study by the present inventors, when the magnetization transition region has an arc shape, the above-described effects are sufficiently obtained when the curvature is in the range of 1/8 to 4 times the user data track pitch. It was. On the other hand, when the magnetization transition region is curved in the shape of an elliptic arc whose major axis or minor axis is the width direction of the reproduction gap of the magnetic head, the diameter of the ellipse reproduction gap in the width direction is 1 of the user data track pitch Tp. The effect was sufficiently obtained in the range of / 4 or more and 8 times or less and the diameter of the elliptical reproduction gap in the direction perpendicular to the width direction was 0.025 μm or more and 2.5 μm or less.

  According to the present invention, since the position detection accuracy of the magnetic head can be improved and sufficient tracking performance can be obtained even in a high track density region, it is useful for increasing the density and reducing the capacity of the hard disk drive. Further, the present invention is not limited to a hard disk drive, and can be applied to a use of a replaceable magnetic disk drive in which a magnetic disk can be attached to and detached from a main body of a magnetic recording / reproducing apparatus, such as a large capacity floppy (registered trademark) disk drive.

Sectional drawing which shows the outline | summary of the recording device for enforcing the magnetic transfer recording method of the information signal in embodiment of this invention The perspective view which shows the example of a structure of the head for magnetization in embodiment of this invention FIG. 2 is a plan view showing the shape of the gap of the magnetizing head shown in FIG. The top view which shows typically the example of a structure of the master information carrier in embodiment of this invention The top view which shows typically the structural example of the arrangement pattern of the information signal formed in a general master information carrier Sectional drawing which shows the example of a structure of the master information carrier in embodiment of this invention The perspective view which shows typically the principle of the direct current | flow erase process of the hard disk in embodiment of this invention The perspective view which shows typically the state of the hard disk by which direct-current erasure | elimination was carried out at the process of FIG. The perspective view which shows the state which is carrying out magnetic transfer recording of the information signal on the hard disk in embodiment of this invention FIG. 9 is a perspective view schematically showing the state of a hard disk on which an information signal is recorded by the process shown in FIG. Sectional drawing for demonstrating the detail of the state of the magnetization at the time of carrying out the magnetic transfer recording of the information signal to a hard disk by the process shown in FIG. Sectional drawing for demonstrating typically the change of the magnetization state at the time of carrying out magnetic transfer recording of the information signal to a hard disk in embodiment of this invention The top view which shows typically the example of a structure of the arrangement pattern of the information signal formed on the surface of the master information carrier in Embodiment 1 of this invention The top view which shows typically the example of a structure of the arrangement pattern of the information signal formed on the surface of the master information carrier in Embodiment 2 of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Hard disk 1a Center hole 1b Information signal recording area 1c Magnetic recording layer 2 Master information carrier 2a Signal area 2b Magnetic part 7 Tracking servo signal 7a, 7b, 7c, 7d Burst signal 8 Address information signal 9 Clock signal 10 Data area 11 Base 11a Concave part of substrate 11b Main surface of substrate 12 Ferromagnetic thin film

Claims (10)

A magnetic recording / reproducing apparatus equipped with a magnetic disk in which a magnetization bit pattern corresponding to an information signal is recorded in advance,
The information signal recorded in advance contains a tracking servo signal, and a magnetization transition region between bits in at least a part of the magnetization bit pattern corresponding to the tracking servo signal is mounted on the magnetic recording / reproducing apparatus. Configured to be curved with respect to the reproducing gap of the magnetic head,
And means for performing tracking control of the magnetic head by detecting a change in the reproduction signal amplitude of the tracking servo signal when the magnetic head is displaced in the radial direction of the magnetic disk. Magnetic recording / reproducing device. The tracking servo signal has a finite recording track width in the radial direction of the magnetic disk,
The tracking servo signal due to the change in the reproduction track width of the tracking servo signal by the magnetic head and the change in the reproduction azimuth loss of the tracking servo signal when the magnetic head is displaced in the radial direction of the magnetic disk 2. The magnetic recording / reproducing apparatus according to claim 1, further comprising means for detecting a change in reproduction signal amplitude of the magnetic head and performing tracking control of the magnetic head. A magnetic recording / reproducing apparatus equipped with a magnetic disk in which a magnetization bit pattern corresponding to an information signal is recorded in advance,
The information signal recorded in advance contains a tracking servo signal, and at least a part of the magnetization bit pattern corresponding to the tracking servo signal is a width of a reproducing gap of a magnetic head mounted on the magnetic recording / reproducing apparatus. A plurality of pairs of magnetization transition regions that are curved in directions opposite to each other are arranged in the circumferential direction of the magnetic disk;
A magnetic recording / reproducing apparatus comprising means for detecting a phase change between the magnetization transition regions accompanying the displacement of the magnetic head in a radial direction of the magnetic disk and performing tracking control of the magnetic head . A magnetic recording / reproducing apparatus equipped with a magnetic disk in which a magnetization bit pattern corresponding to an information signal is recorded in advance,
The information signal recorded in advance contains a tracking servo signal, and at least a part of the magnetization bit pattern corresponding to the tracking servo signal is a width of a reproducing gap of a magnetic head mounted on the magnetic recording / reproducing apparatus. A plurality of pairs of magnetization transition regions that are curved in directions opposite to each other are arranged in the circumferential direction of the magnetic disk;
The tracking servo signal has a finite recording track width in the radial direction of the magnetic disk,
The tracking servo signal due to the change in the reproduction track width of the tracking servo signal by the magnetic head and the change in the reproduction azimuth loss of the tracking servo signal when the magnetic head is displaced in the radial direction of the magnetic disk Detecting a change in reproduction signal amplitude of the magnetic head and detecting a phase change between the magnetization transition region when the magnetic head is displaced in a radial direction of the magnetic disk and a means for performing tracking control of the magnetic head, A magnetic recording / reproducing apparatus comprising means for performing tracking control of the magnetic head. 5. The recording track width in the radial direction of the magnetic disk of the tracking servo signal is ¼ or more and four times or less of a user data track pitch. 2. A magnetic recording / reproducing apparatus according to 1. The magnetization transition region between bits in at least a part of the magnetization bit pattern is curved in an arc shape with respect to the reproduction gap of the magnetic head, and the radius of curvature is not less than 1/8 of the user data track pitch. 5. The magnetic recording / reproducing apparatus according to claim 1, wherein the magnetic recording / reproducing apparatus is four times or less. The magnetization transition region between bits in at least a part of the magnetization bit pattern is curved in an elliptical arc shape having a major axis or a minor axis in the width direction of the reproduction gap with respect to the reproduction gap of the magnetic head, The diameter of the ellipse in the width direction of the reproduction gap is ¼ or more and eight or less times the user data track pitch, and the diameter of the ellipse in the width direction of the reproduction gap is 0.025 μm or more, 5. The magnetic recording / reproducing apparatus according to claim 1, wherein the magnetic recording / reproducing apparatus is 2.5 [mu] m or less. The magnetic recording / reproducing apparatus according to claim 1, wherein the magnetic disk is a replaceable disk that can be attached to and detached from the main body of the magnetic recording / reproducing apparatus. Magnetic recording / reproducing on which the magnetic disk on which the magnetic bit pattern corresponding to the information signal is recorded is mounted by bringing the magnetic disk into contact with the surface of the master information carrier having the shape pattern of the ferromagnetic material corresponding to the information signal A device manufacturing method comprising:
The information signal recorded in advance contains a tracking servo signal, and a magnetic transition region between bits in at least a part of the magnetization bit pattern corresponding to the tracking servo signal is mounted on the magnetic recording / reproducing apparatus. A method of manufacturing a magnetic recording / reproducing apparatus, wherein the magnetic recording / reproducing apparatus is configured to bend with respect to a reproducing gap of a head. At least a part of the magnetization bit pattern corresponding to the tracking servo signal is a pair of magnetizations curved in directions opposite to each other with respect to the width direction of the reproduction gap of the magnetic head mounted on the magnetic recording / reproducing apparatus. The method of manufacturing a magnetic recording / reproducing apparatus according to claim 9, wherein a plurality of transition areas are arranged in a circumferential direction of the magnetic disk.

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