JP4157311B2 - Magnetic recording medium and magnetic recording apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention can perform writing and reading of magnetic information, particularly magnetic information, and magnetically separates a gap between magnetic tracks arranged substantially concentrically and magnetic tracks adjacent in the radial direction. The present invention relates to a disk-shaped magnetic recording medium having a discrete section for the purpose.
[0002]
[Prior art]
A so-called hard disk capable of random access is used as a storage medium such as a computer.
[0003]
In such recording and reproduction on a hard disk, normally, a magnetic head is moved in the radial direction, and a magnetic signal is written or read while confirming that the magnetic head accurately scans a predetermined data track. It is done.
[0004]
By the way, in order to cope with the recent high density recording, for example, as an effective recording medium structure for improving the track density, a so-called discrete track type in which magnetic tracks are magnetically separated is called. Media structure proposals have been made.
[0005]
In such a medium, a dedicated pattern generally called a servo pattern is formed. As this dedicated pattern, a predetermined pattern group shifted by a half track pitch with respect to a data track and a so-called track address are generally formed for tracking.
[0006]
[Problems to be solved by the invention]
However, in a discrete track medium in which the track pitch tends to be narrowed in order to achieve a high recording density, it becomes more difficult to process and form the servo pattern with higher accuracy as the track pitch becomes narrower.
[0007]
In addition, there is a disadvantage that so-called data cannot be recorded in the area where the servo pattern exists, which causes a reduction in the total recording capacity of the magnetic recording medium.
[0008]
The present invention has been devised under such circumstances, and an object thereof is to provide a magnetic recording medium having a novel structure capable of tracking control. Thereby, not only the manufacture of the medium becomes easy, but also the track density and the recording capacity can be improved.
[0009]
[Means for Solving the Problems]
In order to solve such problems, the present invention provides a disk-shaped magnetic recording medium, a magnetic head for writing or reading information on the magnetic recording medium, and a magnetic head that rotates while supporting the magnetic head. A magnetic recording apparatus comprising: an arm that moves a magnetic head to a predetermined radial position of a recording medium; and a control unit that controls driving of the arm for positioning the magnetic head, wherein the magnetic recording medium comprises: A magnetic track arranged substantially concentrically, for writing and reading magnetic information, and a discrete part for magnetically separating a gap between radially adjacent magnetic tracks, the magnetic track Is divided into a plurality of magnetic track units in the circumferential direction by a plurality of radial dividing lines extending in the radial direction from the center of the disk. Knit is subdivided into a plurality of subdivided tracks by a plurality of signals gap formed in a predetermined pattern sequence further circumferential direction, The circumferential length of the subdivided track is set larger than the circumferential length of the signal gap, The pattern arrangement of signal gaps formed in each of the magnetic track units located at the (n−1) th, nth, and n + 1th (where n is an integer of 2 or more) from the center of the disk in the same radial direction is: Each is different And each initial phase is different, The n-th tracking control is performed using the difference in the signal gap pattern arrangement, and each of the (n−1) th and n + 1th magnetic track units adjacent to the nth magnetic track unit is performed. In consideration of the intensity of the signal from the formed signal gap, a control signal for correcting the magnetic head position is output, and the nth tracking control is performed based on this control signal.
[0010]
Further, as a preferred embodiment of the magnetic recording apparatus of the present invention, signal gap pattern arrangements formed on the (n−1) th, nth, and n + 1th magnetic track units in the same radial direction from the disk center. Are different from each other, and the signal gap pattern arrangements formed in the (n−1) -th, n-th and n + 1-th magnetic track units are already stored in advance as arrangement information. The n-th tracking control can be performed using the difference in signal gap pattern arrangement.
[0011]
Further, as a preferred embodiment of the magnetic recording apparatus of the present invention, signal gap pattern arrangements formed on the (n−1) th, nth, and n + 1th magnetic track units in the same radial direction from the disk center. Are formed at substantially equal pitches, and are configured to have different initial phases so as to produce a phase difference between them.
[0012]
As a preferred embodiment of the magnetic recording apparatus of the present invention, when only a signal along the signal gap pattern array formed in the nth magnetic track unit is detected, it is recognized as an on-track state, and adjacent n− When the signal along the pattern arrangement of the signal gap formed in the 1st or n + 1th magnetic track unit is detected as an additional signal, it is turned off to the n-1st or n + 1th magnetic track unit side It recognizes as the state of the track and is configured so that the nth tracking control is possible.
[0013]
As a preferred mode of the magnetic recording apparatus of the present invention, the n-th tracking control is performed by detecting the off-track amount according to the off-track additional signal level.
[0014]
As a preferred aspect of the magnetic recording apparatus of the present invention, the radial dividing line is composed of a non-magnetic portion formed with a certain width, and is used as a timing mark for specifying the start position of the tracking control. Composed.
[0015]
As a preferred aspect of the magnetic recording apparatus of the present invention, the nonmagnetic portion formed with a certain width for forming the radial dividing line further includes a magnetic material portion for timing marks therein. It is comprised so that it may have.
[0016]
Further, as a preferred aspect of the magnetic recording apparatus of the present invention, the plurality of radial dividing lines extending in the radial direction are: Disc center It is comprised so that it may arrange | position by the equal angle division state from.
[0017]
Further, as a preferred aspect of the magnetic recording apparatus of the present invention, the plurality of radial dividing lines extending in the radial direction are: Disc center To be arranged in an arbitrary angle division state different from the above.
[0019]
The present invention includes a magnetic track arranged substantially concentrically for writing and reading magnetic information, and a discrete part for magnetically separating a gap between magnetic tracks adjacent in the radial direction. A disk-shaped magnetic recording medium comprising the magnetic track, Disc center Are divided into a plurality of magnetic track units in the circumferential direction by a plurality of radial dividing lines extending in the radial direction from the magnetic track units, and the magnetic track units are further formed by a plurality of signal gaps formed in a predetermined pattern arrangement in the circumferential direction. Multiple subdivision tracks Signals formed in each of the magnetic track units that are subdivided and located at the (n−1) th, nth, and n + 1th (where n is an integer of 2 or more) from the center of the disk in the same radial direction. The pattern pattern of the gap is Each initial phase is different, and the circumferential length of the subdivided track is set larger than the circumferential length of the signal gap. Configured as follows.
Further, as a preferred embodiment of the magnetic recording medium of the present invention, signal gap pattern arrangements formed on the (n−1) th, nth, and n + 1th magnetic track units in the same radial direction from the disk center. Are configured to be formed at substantially equal pitches.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a so-called perpendicular magnetic recording medium will be described as an example of a preferred specific embodiment of a discrete track type magnetic recording medium of the present invention, and will be described with reference to FIGS.
[0021]
FIG. 1 is a schematic plan view schematically showing the entire shape of the disk-shaped magnetic recording medium 1 of the present invention. FIG. 2A shows a minute portion α surrounded by a square in FIG. A schematic diagram is schematically shown with the portion enlarged and schematically drawn. In particular, FIG. 2A shows a state where a plurality of radial dividing lines 8 extending in the radial direction are divided into a plurality of magnetic track units in the circumferential direction. The division line has a certain width D.
[0022]
FIG. 2B shows an enlarged view of the area indicated by the symbol β in FIG. 2A (the portion drawn in a circle with a dotted line). FIG. 3A is a schematic sectional view showing an embodiment of a perpendicular magnetic recording medium having a relatively simple structure in order to facilitate understanding of the present invention. This corresponds substantially to a cross-sectional view taken along the line (γ)-(γ). FIG. 3B and FIG. 3C each show a preferred modification of FIG. FIG. 4A shows an example of a pattern arrangement of signal gaps formed in the magnetic track units located at the (n−1) th, nth, and n + 1th positions from the disk center in the same radial direction. FIG. 4B represents the on-track and off-track states of the magnetic head as detection signal levels in relation to FIG. 4A. FIG. 5 is a diagram for explaining the relationship between tracking control and writing or reading.
[0023]
A discrete track type magnetic recording medium 1 of the present invention includes magnetic tracks arranged substantially concentrically. In particular, in FIG. 2A, four concentric magnetic tracks 200, 300, 400, 500 are illustrated. Since these are arranged concentrically, strictly speaking, each track line is slightly curved. However, in order to facilitate understanding of the present invention, as shown in FIG. 2A, each track line in a very small area is drawn by approximation in a straight line on the drawing. The magnetic track is used for writing and reading magnetic information.
[0024]
As shown in FIG. 2A, the discrete track type magnetic recording medium 1 of the present invention includes a discrete section 40 for magnetically separating a gap between magnetic tracks adjacent in the radial direction. ing.
[0025]
In addition, the magnetic tracks in the present invention are expressed as “substantially concentrically arranged” as well as so-called “concentric form” as well as so-called “spiral form”. It is a purpose to include.
[0026]
FIG. 3A shows an example of a general shape of the (γ)-(γ) arrow section of FIG. 2A, that is, a radial section. 3A, in the magnetic recording medium 1, the soft magnetic backing layer 10 having the same width as the track width Tw is formed on the nonmagnetic substrate 5, and the same is formed on the soft magnetic backing layer 10. The perpendicular magnetic recording layers 300 and 400 having a width are stacked. The perpendicular magnetic recording layers 300 and 400 in this figure are synonymous with the magnetic tracks 300 and 400 on which writing and reading are performed (see FIG. 2A). Then, in a portion located between these adjacent magnetic tracks 300 and 400, adjacent data tracks are magnetically separated from each other, and a lacking recess 40 (discrete portion 40) for forming a discrete action is formed. Has been. In FIG. 3A, the symbol Tp indicates the pitch of the magnetic track. The pitch Tp of the magnetic tracks is about 20 to 500 nm, and the track width Tw is about 15 to 400 nm.
[0027]
As the non-magnetic substrate 5, those usually used for this type of magnetic recording medium, such as aluminum, tempered glass, crystallized glass, and carbon plastic, may be used.
[0028]
As the soft magnetic backing layer 10, NiFe, NiFeNb, NiFeMo, FeAlSi, FeTaC or the like is preferably used. The thickness of the soft magnetic backing layer 10 is about 0.1 to 10 μm.
[0029]
The perpendicular magnetic recording layers 300 and 400 may be any ones such as CoCr, CoCrTa, CoPt, CoCrPt, CoPtCrO, and TbFeCo, as long as they are normally used for the perpendicular magnetic recording layer of this type of magnetic recording medium. . The thicknesses of the perpendicular magnetic recording layers 300 and 400 may be appropriately selected in consideration of the head to be used, the recording wavelength to be used, and the like. Usually, it is about 10 to 100 nm.
[0030]
On the perpendicular magnetic recording layers 300 and 400, C, ZrO are used for the purpose of protecting the magnetic layer. ₂ , SiO ₂ It is desirable to form a protective film mainly composed of etc. to a thickness of about 1 to 10 nm. If it is formed too thick, a problem of spacing loss tends to occur, and if it is formed too thin, problems such as durability tend to occur. Further, a lubricating film containing various known organic lubricants may be formed on the protective film.
[0031]
The configuration of the magnetic recording medium shown in FIG. 3B is a modification of that of FIG. 3A differs from the medium described in FIG. 3A in that the non-magnetic material 40a is filled in the missing recess 40. FIG. The filled nonmagnetic material 40a has substantially the same function as the discrete portion 40 of FIG. As the non-magnetic material 40a filled in the lacking recess 40, for example, SiO ₂ , Al ₂ O _Three , C and the like are preferably used.
[0032]
The configuration of the magnetic recording medium shown in FIG. 3C is a modification of that of FIG. It differs from the medium described in FIG. 3A in that the soft magnetic backing layer 10 is provided on the entire surface of the substrate 5. As shown in FIG. 3C, a lacking recess 40 (discrete portion 40) is formed in a portion located between adjacent perpendicular magnetic recording layers 300 and 400 (magnetic tracks 300 and 400) to exert a discrete action. Is done.
[0033]
The magnetic tracks 300 and 400 are not limited to materials intended for so-called perpendicular magnetic recording, but may be replaced with materials intended for so-called in-plane recording. In this case, the soft magnetic backing layer 10 may be omitted.
[0034]
As shown in FIG. 1 and FIG. 2 (A), the magnetic tracks arranged concentrically in the present invention have a plurality of radial division lines 8 extending in the radial direction from the disk-shaped center. It is divided into magnetic track units.
[0035]
Such a radial dividing line 8 is normally composed of a non-magnetic portion formed with a constant width D, and is used as a timing mark for specifying the start position of tracking control. Further, a magnetic part for timing marks may be partially formed in the non-magnetic part. The number of division lines 8 is normally about 100 to 1000. The width D is about 50 to 3000 nm.
[0036]
In the embodiment shown in FIG. 1, the plurality of radial division lines 8 extending in the radial direction in this manner are arranged in an equal angular division state from the disc-shaped center. However, the present invention is not limited to this configuration, and a plurality of radial division lines may be intentionally arranged in any angle division state different from the disc-shaped center.
[0037]
With such a dividing line 8, as described above, the magnetic track is divided into a plurality of magnetic track units in the circumferential direction. In FIG. 2A, the magnetic track units are indicated by reference numerals 2001, 2002, 2003; 3001, 3002, 3003; 4001, 4002, 4003; 5001, 5002, 5003.
[0038]
In FIG. 2A, the dividing line 8 extends radially from the bottom to the top of the drawing. Therefore, strictly speaking, the division lines 8 are not in a parallel relationship. However, in the present invention, in order to facilitate the understanding of the invention, the dividing lines 8 in an extremely small area are drawn in parallel approximation on the drawing as shown in FIG.
[0039]
As shown in FIG. 2B, each of the magnetic track units in the present invention is further subdivided by a plurality of signal gaps formed in a predetermined pattern array in the circumferential direction. In FIG. 2B, reference numerals 22a to 22c; 32a to 32c; 42a to 42c; 52a to 52c are partially displayed as signal gaps. The signal gap is normally in a state where no magnetic material exists. Therefore, the magnetic signal level is lowered at the position where this signal gap exists. However, it is also possible to leave a magnetic layer having a slight thickness within a range where the presence of the signal gap can be confirmed as a decrease in the magnetic signal level.
[0040]
By forming such signal gaps at predetermined intervals, a predetermined signal gap pattern, in other words, a predetermined gap timing, is formed in one magnetic track unit.
[0041]
The magnetic track unit 2002 in FIG. 2B is subdivided by signal gaps 22a, 22b, and 22c within the range shown (formation of subdivided tracks 2002a to 2002d). In this embodiment, basically, each signal gap is formed with a predetermined signal gap formation pitch p. However, as shown in the figure, the signal gap 22a initially positioned with respect to the line L1 is set to about 約 of a predetermined signal gap formation pitch p. This is because the gap timing formed in adjacent track units is not the same as illustrated.
[0042]
Similarly, the magnetic track unit 3002 in FIG. 2B is subdivided by signal gaps 32a, 32b, 32c within the range shown (formation of subdivided tracks 3002a to 3002d). In this embodiment, the signal gap is basically formed with the above-mentioned signal gap formation pitch p. However, as shown in the figure, only the signal gap 32a positioned first with reference to the line L1 is set to about 2/3 of the predetermined signal gap formation pitch p. This is to prevent the gap timing formed in adjacent track units from being the same.
[0043]
Similarly, the magnetic track unit 4002 in FIG. 2B is subdivided by signal gaps 42a, 42b, 42c within the range shown (formation of subdivided tracks 4002a to 4002d). In this embodiment, the signal gap is basically formed with the above-mentioned signal gap formation pitch p. As shown in the figure, the signal gap 42a that is initially positioned with respect to the line L1 is also formed with the signal gap formation pitch p described above. This is to prevent the gap timing formed in adjacent track units from being the same.
[0044]
The magnetic track unit 5002 in FIG. 2B is subdivided by signal gaps 52a, 52b, 52c within the range shown (formation of subdivided tracks 5002a to 5002d). In this embodiment, the signal gap formation pattern is the same as that of the magnetic track unit 2002.
[0045]
In this embodiment, by such a technique, a set of track units having three types of gap timings is formed, and these patterns are sequentially repeated in the radial direction to form a track unit group. That is, in the present invention, at least three types of signal formation patterns are required to distinguish the target track to be tracked from the adjacent tracks on both sides. The number of signal gaps formed in one magnetic track unit is, for example, about 3 to 20, and the size of the signal gap is, for example, about 30 to 1000 nm.
[0046]
As described above, at least three adjacent magnetic track units in the magnetic recording medium of the present invention are required to have different signal gap pattern arrangements. That is, at least three types of gap timing are required. If expressed in a more general description, the pattern arrangement of signal gaps formed in the magnetic track units located at the (n−1) th, nth, and n + 1th positions in the same radial direction from the disk center is Are formed differently. The n-th tracking control is performed using the difference in the signal gap pattern arrangement.
[0047]
Hereinafter, specific tracking control will be described with reference to FIGS. 4 (A) and 4 (B).
[0048]
FIG. 4A shows the magnetic tracks Tk located at the (n−1) th, nth, and n + 1th positions in the radial direction from the center of the disk. _(n-1) , Tk _(n) , And Tk _{(n + 1)} 2 shows the pattern arrangement of signal gaps formed in each of the magnetic track units 2002, 3002, and 4002. The signal gap pattern array formed in each magnetic track unit 2002, 3002, 4002 is the same as the signal gap pattern array formed in each magnetic track unit 2002, 3002, 4002 shown in FIG. It corresponds. That is, as described above, the pattern arrangement of the signal gaps formed in the magnetic track units located at the (n−1) th, nth, and n + 1th positions in the radial direction from the disk center is formed at substantially equal pitches. The phases are different from each other.
[0049]
Under such a medium configuration, a magnetic track T on which the magnetic head 7 for writing and reading is positioned at the nth position _{k (n)} Consider tracking control to be on-track.
[0050]
(1) When the magnetic head is at the position (ii) in FIG. 4A, that is, the on-track position, the signal gap formed in the magnetic track unit 3002 shown as (ii) in FIG. Only a gap signal (output reduction signal) corresponding to the pattern arrangement (32a, 32b, 32c...) Is detected. In this case, normally, a control signal for correcting the magnetic head position is not issued.
[0051]
(2) The magnetic head is positioned at (i) in FIG. 4A, that is, adjacent magnetic track Tk. _(n-1) When the track is off-tracked, a gap signal pattern indicated by (i) in FIG. 4B is detected. That is, in addition to the gap signal corresponding to the signal gap pattern arrangement (32a, 32b, 32c...) Formed in the magnetic track unit 3002 to be on-track, the adjacent magnetic track Tk. _(n-1) Tracking information with gap signals added in accordance with the signal gap pattern arrangement (22a, 22b, 22c...) Formed in the magnetic track unit 2002 on the side is obtained (shown by (i) in FIG. 4B). )
[0052]
In this case, for example, a control signal for correcting the magnetic head position is output in consideration of the intensity of the gap signal of the adjacent track unit that should not be expressed. That is, the n-th tracking control is performed by detecting the amount of off-track according to the off-track additional signal level.
[0053]
(3) The magnetic head is positioned at (iii) in FIG. 4A, that is, adjacent magnetic track Tk. _{(n + 1)} When the track is off-tracked, a gap signal pattern indicated by (iii) in FIG. 4B is detected. That is, in addition to the gap signal corresponding to the pattern arrangement of the signal gap formed in the magnetic track unit 3002 to be on-track, the adjacent magnetic track Tk _{(n + 1)} Tracking information to which a gap signal corresponding to the pattern arrangement of the signal gap formed in the magnetic track unit 4002 on the side is added is obtained (shown as (iii) in FIG. 4B).
[0054]
In this case, for example, a control signal for correcting the magnetic head position is output in consideration of the intensity of the gap signal of the adjacent track unit that should not be expressed. That is, the n-th tracking control is performed by detecting the amount of off-track according to the off-track additional signal level.
[0055]
As can be seen from the descriptions in (1) to (3) above, specific tracking for recognizing an on-track state when only a signal along the signal gap pattern array formed in the nth magnetic track unit is detected. As for control, when a signal (output reduction signal) along the signal gap pattern array formed in the adjacent (n−1) th or n + 1th magnetic track unit is detected as an additional signal, the (n−1) th is detected. Alternatively, the n-th tracking control can be performed according to the level of the off-track additional signal by recognizing the off-track state on the n + 1-th magnetic track unit side.
[0056]
Note that the pattern arrangement of the signal gaps formed in the (n−1) -th, n-th, and n + 1-th magnetic track units has already been stored in advance as storage information in the control circuit (for example, ROM (Read Only Memory)). Therefore, in the example shown in FIG. 4 described above, the signal gap pitch p is basically the same to facilitate understanding of the invention. However, there are track units having at least three types of gap timing. It is enough. Of course, a track unit having three or more types of gap timings may be used. Note that the above-described position detection (n-th tracking control) is preferably performed comprehensively with several tens of signal gaps formed in one magnetic track unit in order to eliminate the influence of noise and the like.
[0057]
Next, the relationship between the tracking control performed using the magnetic recording medium of the present invention and magnetic information writing or information reading will be described with reference to FIG.
[0058]
In the present invention, as shown in FIG. _(n) Tracking control (track position detection) as described with reference to FIG. 4 is performed using at least one magnetic track unit 3001 in the track). Information is written to or read from another magnetic track unit on the same circumference other than the magnetic track unit 3001 subjected to the tracking control, for example, the magnetic track unit 3002 at the next position.
[0059]
Thereafter, as shown in FIG. 5, for example, tracking control (track position detection) is performed in the next magnetic track unit 3003, and another magnetic track unit 3003 other than the magnetic track unit 3003 on which the tracking control is performed is performed. Information is written to or read from a track unit, for example, the track unit 3004 at the next position.
[0060]
That is, using one magnetic track unit, tracking control is performed to keep the magnetic head in an on-track state, and after confirming or correcting this on-track state, the information is transferred to the next magnetic tracking unit. Writing or reading of information is performed. In order to improve on-track accuracy and ensure reliable on-track, it is desirable to alternate such position confirmation and read / write operations as much as possible, but every second, every third, and more It may be. Of course, the magnetic tracking unit used for position detection (tracking) can be used later for writing information or reading information. On the contrary, the magnetic tracking unit used for writing information or reading information can be used later for position detection (tracking). This is because the high-frequency current used for writing and the gap signal for position detection can be clearly distinguished.
[0061]
As shown in FIG. 5, AGC (Auto Gain Control) in the signal reproduction circuit needs to be held while the position detection (tracking) operation is performed. This is because when the AGC acts, it is impossible to detect the output drop of the tracking signal gap.
[0062]
Note that the magnetic recording medium of the present invention does not include a conventionally formed servo pattern having a complicated shape. Therefore, there is no track address or servo burst pattern. Therefore, cylinder position, track position, sector position, etc. are included in a part of the data track. It is necessary to write data such as a groove code, and an initialization format for that purpose is required.
[0063]
The magnetic recording medium as described above is used by being incorporated in a magnetic recording apparatus. That is, the magnetic recording apparatus includes the above-described disk-shaped magnetic recording medium, a magnetic head for writing or reading information on the magnetic recording medium, and rotating while supporting the magnetic head. An arm that moves the magnetic head to a predetermined radial position and a control unit that controls driving of the arm for positioning the magnetic head. Among these magnetic recording apparatus configurations, the characteristics of the magnetic recording apparatus exist in particular in the configuration of the disk-shaped magnetic recording medium and the control mechanism of the control unit that should exert the effects of the medium. That is, based on the structure of the magnetic recording medium described above, the control unit recognizes the time when only the signal along the signal gap pattern array formed in the nth magnetic track unit is detected as an on-track state. When the signal along the pattern arrangement of the signal gap formed in the adjacent (n−1) th or (n + 1) th magnetic track unit is detected as an additional signal, the n−1th or (n + 1) th magnetic field is detected. The track unit recognizes it as an off-track state, and the n-th tracking control is performed according to the signal level of the off-track amount.
[0064]
【The invention's effect】
The present invention includes a magnetic track arranged substantially concentrically for writing and reading magnetic information, and a discrete part for magnetically separating a gap between magnetic tracks adjacent in the radial direction. A disk-shaped magnetic recording medium provided, wherein the magnetic track is divided into a plurality of magnetic track units in a circumferential direction by a plurality of radial division lines extending in a radial direction from a disk-shaped center, and the magnetic track unit is Are further subdivided by a plurality of signal gaps formed in a predetermined pattern arrangement in the circumferential direction, and are n−1th, nth, and n + 1th in the same radial direction from the disc center (where n is The pattern arrangement of the signal gap formed in each of the magnetic track units located at an integer of 2 or more is different. n-th tracking control is to be carried out by utilizing a difference in the pattern arrangement of signal gaps. Due to the medium having such a simple structure, the manufacturing is facilitated and the tracking control can be surely performed. Further, the track density and the recording capacity can be improved.
[Brief description of the drawings]
FIG. 1 is a schematic plan view showing the overall shape of a disk-shaped magnetic recording medium of the present invention.
2A is a schematic diagram schematically illustrating an enlarged portion of a minute portion α surrounded by a square in FIG. 1, and FIG. 2B is a schematic diagram illustrating FIG. FIG.
FIG. 3A is a schematic cross-sectional view showing an embodiment of a perpendicular magnetic recording medium having a relatively simple structure in order to facilitate understanding of the present invention. This corresponds substantially to the (γ)-(γ) cross-sectional view of (A). FIG. 3B and FIG. 3C each show a preferred modification of FIG.
FIG. 4A shows an example of a pattern arrangement of signal gaps formed in magnetic track units located at the (n−1) th, nth, and n + 1th positions in the radial direction from the disk center. FIG. 4B shows the on-track and off-track states of the magnetic head as detection signal levels in relation to FIG. 4A.
FIG. 5 is a drawing for explaining the relationship between tracking control and writing or reading;
[Explanation of symbols]
1 ... Magnetic recording medium
5. Non-magnetic substrate
8 ... Ward line
10 ... Soft magnetic backing layer
22a-22c; 32a-32c; 42a-42c; 52a-52c ... signal gap
40: Discrete part (missing recess)
200, 300, 400, 500 ... Magnetic track (magnetic recording layer)
2001 to 2003; 3001 to 3003; 4001 to 4003; 5001 to 5003... Magnetic track unit

Claims (3)

A disk-shaped magnetic recording medium;
A magnetic head for writing or reading information on a magnetic recording medium;
An arm that rotates while supporting the magnetic head and moves the magnetic head to a predetermined radial position of the magnetic recording medium;
A magnetic recording device having a control unit for controlling the driving of the arm for positioning the magnetic head,
The magnetic recording medium is arranged substantially concentrically, and includes a magnetic track for writing and reading magnetic information and a discrete portion for magnetically separating a gap between the radially adjacent magnetic tracks. Prepared,
The magnetic track is divided into a plurality of magnetic track units in the circumferential direction by a plurality of radial dividing lines extending in a radial direction from the center of the disk,
The magnetic track unit is further subdivided into a plurality of subdivided tracks by a plurality of signal gaps formed in a predetermined pattern arrangement in the circumferential direction,
The circumferential length of the subdivided track is set larger than the circumferential length of the signal gap,
The pattern arrangement of signal gaps formed in each of the magnetic track units located at the (n−1) th, nth, and n + 1th (where n is an integer of 2 or more) from the center of the disk in the same radial direction is: Each is different, and each initial phase is different, and the nth tracking control is performed using the difference in the pattern arrangement of these signal gaps,
A control signal for correcting the magnetic head position is output in consideration of the signal strength from the signal gap formed in each of the (n−1) th and (n + 1) th magnetic track units adjacent to the nth magnetic track unit. And the nth tracking control is performed based on the control signal. A disk-shaped disk that is substantially concentrically arranged and includes a magnetic track for writing and reading magnetic information, and a discrete part for magnetically separating a gap between magnetic tracks adjacent in the radial direction. A magnetic recording medium,
The magnetic track is divided into a plurality of magnetic track units in the circumferential direction by a plurality of radial dividing lines extending in a radial direction from the center of the disk,
The magnetic track unit is further subdivided into a plurality of subdivided tracks by a plurality of signal gaps formed in a predetermined pattern arrangement in the circumferential direction,
The pattern arrangement of signal gaps formed in each of the magnetic track units located at the (n−1) th, nth, and n + 1th (where n is an integer of 2 or more) from the center of the disk in the same radial direction is: Each initial phase is different,
The magnetic recording medium according to claim 1, wherein a length of the subdivided track in the circumferential direction is set larger than a length of the signal gap in the circumferential direction. N-1 th toward the disk center in the same radial direction, n th, and the pattern arrangement of the signal gap formed in each magnetic track unit located n + 1 th, claims formed by formed in a substantially equal pitch Item 3. The magnetic recording medium according to Item 2 .

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