JP5620664B2 - Magnetic recording / reproducing device - Google Patents

Description

  The present invention relates to a magnetic recording / reproducing apparatus, and more particularly to a magnetic recording / reproducing apparatus having excellent track following performance on a disk made of patterned media.

  In recent years, with technological innovation in the IT industry and the like, research and development for increasing the capacity, speed, and cost of magnetic recording media has been actively conducted. In order to increase the capacity, speed, and cost of the magnetic recording medium, it is essential to improve the recording density of the magnetic recording medium. Conventionally, attempts have been made to improve the recording density of the magnetic recording medium by in-plane recording of continuous magnetic film formation on the magnetic recording medium, but the technical limit is approaching.

  For example, when the recording density of a magnetic recording medium is increased, the area of the “recording bit” that is the minimum recording unit becomes smaller and smaller than a certain range, and a phenomenon called “thermal fluctuation” occurs at room temperature. However, a long-term recording magnetic field cannot be maintained.

  Therefore, recently, the “perpendicular magnetic recording” method has attracted attention as a new recording method that replaces the in-plane recording (longitudinal magnetic recording). In perpendicular magnetic recording, the demagnetizing field due to the reversal of recording magnetization works in the direction of increasing the magnetization, so that even a fine bit has high thermal stability and can cope with high density.

  As a technique aiming at further improvement in recording density, a perpendicular magnetic recording medium using a patterned media medium has been proposed. The patterned media medium has a single magnetic domain structure instead of a complex magnetic domain by forming the magnetic film in the magnetic recording medium into a pattern of dots, bars, pillars, etc., instead of a continuous film, and by setting the size to a nanometer scale. Media is used (for example, see Non-Patent Document 1). Side crosstalk can be reduced by patterning the recording portion and separating the individual recording layers.

  On the other hand, the key to improving the performance of HDD drives is certainly to increase the recording density of the magnetic recording medium, but if the recording density is increased, the performance will not naturally improve. The high recording density is because playback / recording must be performed in a shorter time if the rotational speed of the disk is the same. In addition, it is essential to improve position control technology for accurately capturing minute bits with a reading head.

In a conventional magnetic recording medium, a signal information line and a servo signal line are provided.
When recording, the position control signal is first read by the magnetic head on the servo signal line to control the position of the magnetic head. Then, the sector and track positions are confirmed. Thereafter, the signal was recorded on the desired track.

  For example, Patent Document 1 uses a composite magnetic head including a recording head and a reproducing head, and includes a data area and a servo signal area on the recording surface of the magnetic recording medium, and includes a recording track and a servo signal area in the data area. A magnetic recording / reproducing apparatus has been proposed in which the recording tracks are arranged with a half-pitch offset from each other to increase the recording density, but this is not sufficient.

  Thus, if the servo signal area is provided on the magnetic recording medium, the recording area is reduced accordingly. Further, if the position control of the magnetic head and the signal recording are separately performed, the recording takes time, and it is difficult to realize a higher recording density recording.

JP-A-5-073872

S.Y.Chou Proc.IEEE 85 (4), 652 (1997)

  The present invention has been devised in view of such a conventional situation, and an object of the present invention is to provide a magnetic recording / reproducing apparatus capable of improving recording speed and realizing higher density recording.

According to a first aspect of the present invention, there is provided a magnetic recording / reproducing apparatus in which a local region having a magnetic characteristic whose polarity changes in a direction perpendicular to the substrate surface on one or both surfaces of a disk-shaped substrate is separated by a predetermined distance. A plurality of concentric magnetic recording media arranged at a distance p; a recording head for writing information to the magnetic recording medium; and a reproducing head for reading information from the magnetic recording medium; A magnetic recording / reproducing apparatus including a recording head and a magnetic head in which the reproducing head is locally arranged at a predetermined interval d in the portion, wherein the gap center position of the recording head, and the reproducing head of the gap center position, together with the d is arranged so as to satisfy d = np (n is 3), a local region in the magnetic recording medium is a magnetic bit, magnetic The position information in Tsu bets itself is stored, and wherein.

The magnetic head mounted on the magnetic recording / reproducing apparatus of the present invention includes a part provided with a recording head for writing information to a magnetic recording medium and a reproducing head for reading information from the magnetic recording medium, and the part The recording head and the reproducing head are locally arranged at a predetermined interval d. In addition to this, the gap center position of the recording head and the gap center position of the reproducing head are arranged with an interval d satisfying d = np (n is 3) . Therefore, in the magnetic recording / reproducing apparatus of the present invention, after confirming the writing position by the reproducing head, it can be seen that the recording head comes to the writing position after n (= 3) bits. Thus, by storing position information in the local area itself, it is not necessary to provide a servo pattern area on the disk, and high density recording can be realized. Further, since the signal can be continuously recorded by the recording head after the writing position is confirmed by the reproducing head, the recording speed can be improved. As a result, the present invention can provide a magnetic recording / reproducing apparatus capable of realizing higher density recording.

1 is a cross-sectional view schematically showing an example of a magnetic recording / reproducing apparatus of the present invention. The top view which shows typically an example of the magnetic recording / reproducing apparatus of this invention. The figure which shows the relationship between the position of a magnetic head and a magnetic bit, and a magnetic signal.

  Hereinafter, preferred embodiments of the magnetic recording / reproducing apparatus of the present invention will be described.

1 and 2 are diagrams schematically showing an example of a magnetic recording / reproducing apparatus according to the present invention. FIG. 1 is a cross-sectional view, and FIG. 2 is a top view.
In the magnetic recording / reproducing apparatus of the present invention, a local region having a magnetic characteristic whose polarity changes in a direction perpendicular to the substrate surface on one surface or both surfaces (one surface in the example shown in FIG. 1) of the disk-shaped substrate 10. A magnetic recording medium 1 in which a plurality of magnetic bits 31) are arranged concentrically with a predetermined separation distance p, a recording head 110 for writing information to the magnetic recording medium 1, and the magnetic recording medium 1 A magnetic head 100 including a reproducing head 120 for reading information from the recording head 110. In the magnetic head 100, the gap center position of the recording head 110 and the gap center position of the reproducing head 120 are d = np (n is And an interval d that satisfies an integer of 3 or more.

  In the magnetic recording / reproducing apparatus of the present invention, the gap center position of the recording head 110 and the gap center position of the reproducing head 120 are arranged with an interval d satisfying d = np (n is an integer of 3 or more). After confirming the writing position with the reproducing head 120, it can be seen that the recording head 110 comes to the writing position after n bits. Thus, by storing the position information in the magnetic bit 31 itself, it is not necessary to provide a servo pattern area on the disk, and high density recording can be realized. In addition, since the recording head 110 can continuously record a signal after confirming the writing position with the reproducing head 120, the recording speed can be improved. As a result, the magnetic recording / reproducing apparatus of the present invention can realize further high density recording.

  As an example of performing magnetic recording on a magnetic recording medium by a recording method by perpendicular recording, a magnetic head 100 of perpendicular magnetic recording method is opposed to a recording layer 30 of the magnetic recording medium 1 as shown in FIG.

The magnetic recording medium 1 has a disk-like substrate 10 made of a nonmagnetic material such as ceramic, and an underlayer 20 and a recording layer 30 arranged in this order on one surface of the substrate 10.
In the magnetic recording medium 1, in the recording layer 30, a plurality of magnetic bits 31 (local regions) having magnetic characteristics whose polarity changes in a direction perpendicular to the substrate surface are concentrically formed with a predetermined separation distance p. It is arranged. A nonmagnetic region 32 is provided between the magnetic bit 31 columns.
Specifically, as will be described later, in the magnetic recording medium 1, the position information is stored in the magnetic bit 31 itself without providing the servo information area.

The magnetic head 100 includes a recording head 110 that writes information to the magnetic recording medium 1 and a reproducing head 120 that reads information from the magnetic recording medium 1. The magnetic head 100 shown in FIG. 1 and FIG. 2 is a partial schematic view showing an enlarged portion where the recording head 110 and the reproducing head 120 are provided, and the whole is omitted.
In the magnetic head 100, the recording head 110 and the reproducing head 120 are not particularly limited and may be appropriately selected depending on the purpose. As the recording head 110, for example, a single magnetic pole head or the like is preferably used. Further, as the reproducing head 120, for example, a GMR head or the like is preferably exemplified.

  In the magnetic recording / reproducing apparatus of the present invention, in the magnetic head 100, the gap center position of the recording head 110 and the gap center position of the reproducing head 120 satisfy d = np (n is an integer of 3 or more). It is characterized by being arranged with an interval d.

  In a conventional magnetic recording medium, a servo information area is provided on the disk surface. In the servo information area, two pieces of information are stored: position information between the magnetic head (recording head and reproducing head) and the track, and recording / reproducing area information of the sector and track.

  In the present invention, without providing a servo information area on the disk surface, track information and head position correction information are obtained directly from a magnetic bit and reproduced and recorded. That is, position information is stored in the magnetic bit itself. As a result, it is not necessary to provide a servo information area on the disk surface, and high density recording can be realized.

  The servo operation in the magnetic recording / reproducing apparatus of the present invention will be described below. In the following description, the case of n = 3 will be described as an example. Note that the present invention is not limited to this example, and can be similarly applied to cases other than n = 3.

(1) First, in the magnetic recording medium 1, a rule is provided for the arrangement of the magnetic bits 31. For example, as shown in FIG. 1A, the magnetic pattern of the magnetic bit 31 is set to “N pole, N pole, N pole, S pole” in the rotation direction. At this time, from the beginning to the third rotation, the magnetic bit 31n of N pole, N pole, and N pole is recognized as a sector, and the magnetic bit 31p of S pole is recognized as an edge (boundary) of the sector.

(2) Then, the magnetic head 100 is scanned from the inner diameter toward the outer diameter to obtain the number of tracks and the track pitch of the magnetic bits. The moving angle θ of the magnetic head 100 with respect to the magnetic recording medium 1 rotating at a constant linear velocity is stored.

(3) After setting the track position, the center position of the gap of the reproducing head 120 and the center position of the magnetic bit 31 are matched so that the read signal waveform becomes maximum.
Here, FIG. 3 is a diagram showing the relationship between the position of the magnetic head 100 and the magnetic bit 31 in FIG. 2 and the magnetic signal. In FIG. 2, when the magnetic head 100 travels at positions B and C, that is, away from the center of the magnetic bit 31, the waveform of the read magnetic signal becomes small as shown in FIGS. However, when the magnetic head 100 travels at the position A in FIG. 2, that is, on the center of the magnetic bit 31, as shown in FIG. 3A, the waveform of the read magnetic signal becomes large. That is, as shown in FIG. 3A, the magnetic head 100 is made to travel where the waveform has the highest height. Thereby, the center position of the gap of the reproducing head 120 and the center position of the magnetic bit 31 can be matched.

(4) Then, after confirming the frequency of the magnetic bit 31 signal picked up when the substrate 10 travels with the reproducing head 120, the recording head 110 writes desired magnetization into the magnetic bit 31.
As shown in FIG. 1A, when the magnetic head 100 is placed on the magnetic bit, the position of the magnetic pole 31s of the S pole on the reproducing head 120 [the position indicated by the dotted line in FIG. recognize. At this time, the gap center position of the recording head 110 and the gap center position of the reproducing head 120 are spaced apart by d = 3p. Therefore, as shown in FIG. It can be determined that the recording head 110 comes to the position of the magnetic pole 31s of the S pole 3 bits after the position of the magnetic bit 31s of the pole [the position indicated by the dotted line in FIG. 1B] is recognized. That is, after the reproducing head 120 recognizes the position of the magnetic pole 31s of the south pole, writing is started by the write head 3 bits later.

  As described above, in the present invention, by storing position information in the magnetic bit itself, it is not necessary to provide a servo pattern area on the disk, and high density recording can be realized. Further, since the signal can be continuously recorded by the recording head after the writing position is confirmed by the reproducing head, the recording speed can be improved. As a result, the magnetic recording / reproducing apparatus of the present invention can realize further high density recording.

  The magnetic recording / reproducing apparatus of the present invention has been described above. However, the present invention is not limited to the above-described example, and can be appropriately changed without departing from the spirit of the invention.

  The present invention is applicable to a magnetic recording / reproducing apparatus including a disk-shaped magnetic recording medium and a magnetic head.

  DESCRIPTION OF SYMBOLS 1 Magnetic recording medium, 10 Substrate, 20 Underlayer, 30 Recording layer, 31 Magnetic bit (local area), 32 Nonmagnetic area, 100 Magnetic head, 110 Recording head, 120 Playback head

Claims (3)

A magnetic recording medium in which a plurality of local regions having magnetic characteristics whose polarity changes in a direction perpendicular to the substrate surface are arranged concentrically with a predetermined separation distance p on one or both surfaces of a disk-shaped substrate When,
Including a recording head for writing information to the magnetic recording medium and a portion provided with a reproducing head for reading information from the magnetic recording medium, and the recording head and the reproducing head are locally located at a predetermined interval d in the portion. A magnetic recording / reproducing apparatus comprising a magnetic head,
The gap center position of the recording head and the gap center position of the reproducing head are arranged so that d satisfies d = np (n is 3), and the local area in the magnetic recording medium is a magnetic bit. A magnetic recording / reproducing apparatus characterized in that position information is stored in the magnetic bit itself .   The magnetic recording / reproducing apparatus according to claim 1, wherein the magnetic recording medium does not require a servo information (servo pattern) area.   2. The magnetic recording / reproducing apparatus according to claim 1, further comprising a configuration in which a gap center position of the reproducing head is aligned with a center position of the magnetic bit based on a waveform of a read signal of the reproducing head.

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