CN100444248C - Magnetic recording and reproducing device - Google Patents

Abstract

In the magnetic recording and reproducing device of the present invention, the pattern shape of the burst area on the discrete medium has a substantially trapezoidal shape (square pyramidal trapezoid) respectively in the track width direction and the track circumferential direction, and the trapezoidal shape in the track width direction When the upper side corresponding to the surface of the convex magnetic recording layer is W1, the lower side corresponding to the lower side of the convex magnetic recording layer is W2, the data track pitch of the data information recording part is Tp, and the read width of the magnetic head is Wr , satisfies the predetermined relationship, so the burden on the manufacture of the pattern shape of the burst area in the process is very small, and an accurate position error signal can also be obtained.

Description

Magnetic recording and reproducing device

technical field

The present invention relates to a magnetic recording medium (discrete magnetic recording medium) having a magnetic recording layer formed in a predetermined concave-convex pattern on a substrate and having a so-called servo area and an information data area, and recording and recording a servo signal of the medium simultaneously. A magnetic recording and reproducing device for a magnetic head that reproduces information data.

Background technique

Conventionally, the improvement of the areal recording density of magnetic recording media such as hard disks has been achieved by (1) increasing the linear recording density and (2) increasing the track density. In order to achieve a higher density in the future, it is necessary to increase the recording density based on the above two methods.

Regarding the improvement of track density, there are obviously problems such as side fringe and crosstalk caused by the processing limit of the magnetic head or the expansion of the magnetic field of the magnetic head. Said the limit had been reached.

On the one hand, as a method of increasing the linear recording density, although thin layers and high coercive force have been achieved in conventional longitudinal magnetic media, it is attracting attention from the viewpoint of stability against thermal fluctuations in media density and recording magnetization. It is a perpendicular magnetic recording medium satisfying these conditions.

Based on such current situation, as a technique to increase the areal recording density and to complement the high track density of the magnetic head, a discrete track disk type magnetic recording medium in which the recording layer is formed in a predetermined concave-convex pattern has been proposed. For example, Japanese Patent Application Laid-Open No. 11-328662 discloses a magnetic recording medium in which a predetermined unevenness is provided on a substrate and a single perpendicular magnetic layer is formed along the unevenness.

Achieving high recording density requires low space reduction. However, the uneven shape of the recording layer prevents the magnetic head from obtaining stable levitation characteristics, which may cause problems such as head collision. Based on such a viewpoint, Japanese Patent Application Laid-Open No. 10-222944 discloses a recording medium in which the uneven shape in the track width direction is changed for the purpose of head suspension stability.

In addition, Japanese Patent Application Laid-Open No. 2000-195042 proposes a discrete magnetic recording medium in which concave-convex-shaped recesses are filled with a non-magnetic material or other materials to ensure the stability of the suspension characteristics of the magnetic head.

In addition, Japanese Patent Application Laid-Open No. 6-111502 discloses a technology for specifying the relationship between the burst pattern width, track pitch, and readout width of the reproducing head in tracking servo of a rectangular concave-convex structure in a longitudinal recording medium. .

In general, in a magnetic recording medium used in a magnetic disk device, a servo region for head tracking is recorded by a servo track recorder.

In the servo area, there are generally ISG (Initial Signal Gain) section, SVAM (SerVoAddress Mark) section, gray code section, burst section, and filling section, which form various magnetic patterns in order to perform predetermined functions.

In these magnetic patterns, burst portions are generally recorded with a width of about 1 track pitch in the radial direction of the magnetic recording medium. In addition, the ISG portion, the SVAM portion, the Gray code portion, and the filling portion are usually continuously recorded in the radial direction of the disc, or are recorded continuously in the radial direction at least several tracks.

The burst portion is a pattern for obtaining accurate positional information for the magnetic head to accurately track the track position. The pattern of such a burst portion is, for example, composed of (1) a group of first burst areas and second burst areas arranged equally across the center line defining the adjacent track pitch, (2) or, the first burst area In addition to the group of the burst area and the second burst area, a group of the third burst area and the fourth burst area located at a position shifted from the group by half a track pitch is added.

An example of the tracking operation in the simplest combination of the first burst area and the second burst area is as follows. That is, the magnetic head sequentially passes through the first burst area and the second burst area, thereby comparing the reproduced signal Sa from the pattern of the first burst area with the reproduced signal Sb from the pattern of the second burst area according to the differential amplifier to obtain the position Error signal PES (Position Error Signal) = (Sa-Sb) value. The value of the position error signal PES=(Sa-Sb) is input to the servo control circuit, and the tracking servo actuator is driven according to the magnitude of the position error signal, so that the center of the magnetic head follows the center of the data track.

However, the burst pattern in traditional discrete media is a rectangular pattern. Although the rectangular pattern is ideal for obtaining accurate position error signals, very high precision is required in terms of shape and size when forming a rectangular shape.

This requirement of forming accuracy will impose a great burden on the manufacturing process.

In order to solve this problem, the present applicant has proposed the invention of Japanese Patent Application No. 2004-188121, that is, a magnetic recording and reproducing apparatus having a discrete medium having two pairs (two sets) of burst pattern The pattern shape of the burst region is made into a substantially trapezoidal shape (square pyramidal trapezoid) in the track width direction and the track circumferential direction, and the corresponding surface of the convex magnetic recording layer is set in the trapezoidal shape in the track width direction. The predetermined relationship is satisfied when the upper side is W1, the lower side corresponding to the bottom surface of the convex magnetic recording layer is W2, the data track pitch of the data information recording part is Tp, and the read width of the magnetic head is Wr. According to this aspect, it is possible to provide a magnetic recording and reproducing apparatus using a magnetic recording medium having a burst pattern shape with a very small manufacturing burden on the process and also capable of obtaining an accurate position error signal.

Based on such current situation, (1) the first group invention of the present application and (2) the second group invention of the present application have been conceived.

(1) The purpose of the first group of inventions of the present application is to: in the discrete media with 2 pairs (2 groups) of burst pattern proposed by the applicant, it is confirmed through experiments that the effect of changing the track pitch and the segment pitch There is also an optimal usable range when there is a relationship, and the application for the present invention claims to protect this expanded use range. That is, the present invention provides a magnetic recording and reproducing device using a magnetic recording medium having a burst pattern shape that has a very small manufacturing burden on the process and can accurately obtain a position error signal even if the range of use is further expanded.

(2) The purpose of the second group of inventions of the present application is to provide a process that adopts a process-based manufacturing method when the pattern of the burst area is further increased, and the relationship between the track pitch and the segment pitch is diversified in various ways. A magnetic recording and reproducing device for a magnetic recording medium having a burst pattern shape with minimal burden and an accurate position error signal can be obtained. By increasing the burst pattern, the practical range in which accurate position error signals can be obtained can be expanded, and the allowable range in device design can be expanded.

Contents of the invention

In order to solve the problem described in (1) above,

The magnetic recording and reproducing device of the first group of inventions of the present application is provided with: a magnetic recording medium including a data information recording part and a servo information part for tracking; while detecting the servo information of the servo information part, the data information A magnetic head for recording and reproducing the data information recording portion, wherein the data information recording portion has a data track with a data track pitch Tp, and the servo information portion is composed of a magnetic recording layer formed in a predetermined concave-convex pattern. The servo information section includes a burst section for recording a burst signal for tracking, and the burst section includes a first burst area, a second burst area, and a second burst area composed of a magnetic recording layer on which a plurality of convex portions of the burst signal are recorded. A burst area, a third burst area, and a fourth burst area, the first burst area and the second burst area are arranged in pairs, and are staggered from each other at a distance of 2 track pitches (2Tp) in the track width direction In the magnetic recording layer where the convex portion is formed on the central line, the third burst region and the fourth burst region are arranged in pairs, centered at positions shifted by a distance of 2 track pitches (2Tp) from each other in the track width direction line forming the magnetic recording layer of the protrusion, and the third burst area and the fourth burst area are configured to be staggered from the center line of the first burst area and the second burst area by a distance of 1 track pitch ( 1Tp) where the center line forms the magnetic recording layer of the convex portion, the magnetic recording layer of the convex portion has a substantially trapezoidal shape (square pyramid trapezoidal) in the track width direction and the track circumferential direction, respectively, and in the track width direction On the trapezoidal shape, set the upper side corresponding to the surface of the convex magnetic recording layer as W1, the lower side corresponding to the bottom surface of the convex magnetic recording layer as W2, the data track pitch of the data information recording part as Tp, the readout of the magnetic head When the width is Wr, if W1>Tp, the condition of 1.25W2>Wr≥0.5W2 is satisfied.

In addition, the magnetic recording and reproducing device of the first group of inventions of the present application is provided with: a magnetic recording medium including a data information recording unit and a servo information unit for tracking; while detecting the servo information of the servo information unit, A magnetic head for recording and reproducing data information in the data information recording portion, wherein the data information recording portion has a data track with a data track pitch Tp, and the servo information portion is composed of a magnetic recording layer formed in a predetermined concave-convex pattern , the servo information section has a burst section for recording a burst signal for tracking, and the burst section includes a first burst area composed of a magnetic recording layer on which a plurality of convex portions of the burst signal are recorded, a second burst area, and a second burst area. The second burst area, the third burst area and the fourth burst area, the first burst area and the second burst area are configured in pairs, and each other is in the track width direction with a (2/3) track pitch. The position staggered by the distance ((2/3)Tp) is the central line to form the magnetic recording layer of the protrusion, and the third burst area and the fourth burst area are arranged in pairs, and are spaced apart from each other in the track width direction by (2/ 3) The distance ((2/3)Tp) of the track pitch is staggered to the center line to form a magnetic recording layer with a convex portion, and the third burst area and the fourth burst area are configured to be separated from the first The position where the center line of the burst area and the second burst area is staggered by the distance ((1/3) Tp) of the track pitch (1/3) is the center line to form the magnetic recording layer of the convex part, and the magnetic recording layer of the convex part is formed. The recording layer has a substantially trapezoidal shape (square pyramidal trapezoid) in the track width direction and the track circumferential direction, respectively. In the trapezoidal shape in the track width direction, the upper side corresponding to the surface of the convex magnetic recording layer is W1, and When the lower side corresponding to the bottom surface of the convex magnetic recording layer is W2, the data track pitch of the data information recording part is Tp, and the read width of the magnetic head is Wr, if Tp>W2, the condition of 1.5W2≥Wr≥0.5W1 is satisfied .

In addition, the ideal form of the first group of inventions of the present application is as follows: when the height from the lower side of the convex magnetic recording layer, that is, W2, to the upper side, that is, W1, is h, it satisfies tan85°≥2h/(W2-W1)≥tan50° conditions of.

In addition, the ideal form of the first group of inventions of the present application is as follows: when W is the data track width, Wr is the magnetic read width, and Tp is the track pitch, Wr<2Tp-W is satisfied.

In order to solve the problems described in (2) above,

The magnetic recording and reproducing device of the second group of inventions of the present application is provided with: a magnetic recording medium including a data information recording part and a servo information part for tracking; while detecting the servo information of the servo information part, the data information A magnetic head for recording and reproducing the data information recording portion, wherein the data information recording portion has a data track with a data track pitch Tp, and the servo information portion is composed of a magnetic recording layer formed in a predetermined concave-convex pattern. The servo information section includes a burst section for recording a burst signal for tracking, and the burst section includes a first burst area, a second burst area, and a second burst area composed of a magnetic recording layer on which a plurality of convex portions of the burst signal are recorded. The first burst area, the third burst area, the fourth burst area, the fifth burst area and the sixth burst area, the first burst area and the second burst area are configured in pairs, and they are in the track width direction A magnetic recording layer in which protrusions are formed at a position shifted by a distance of 1 track pitch (1Tp) as a center line, and the third burst area and the fourth burst area are arranged in pairs, and are separated from each other by 1 track in the track width direction. The position staggered by the distance (1Tp) of the pitch is the magnetic recording layer of the convex portion formed on the center line, and the third burst area and the fourth burst area are configured to be separated from the first burst area and the second burst area. The position where the central line of the zone is staggered by the distance ((1/3)Tp) of the track pitch (1/3) is the central line to form a convex magnetic recording layer, and the fifth burst zone and the sixth burst zone are configured A pair of magnetic recording layers that form protrusions at positions offset from each other by a distance of 1 track pitch (1Tp) in the track width direction as the center line, and the fifth burst area and the sixth burst area are arranged so as to be from The center lines of the first burst area and the second burst area are respectively staggered by the distance ((2/3)Tp) of the track pitch (2/3) as the center line to form the magnetic recording layer of the convex part, so The magnetic recording layer of the convex portion has a substantially trapezoidal shape (square pyramidal trapezoidal shape) in the track width direction and the track circumferential direction, respectively, and on the trapezoidal shape in the track width direction, a surface corresponding to the surface of the convex magnetic recording layer is provided. When the upper side is W1, the lower side corresponding to the bottom surface of the convex magnetic recording layer is W2, the data track pitch of the data information recording part is Tp, and the read width of the magnetic head is Wr, if Tp>W2, then 2W2>Wr≥ 0.5W2 and the condition of 0.5W2<W1.

In addition, the magnetic recording and reproducing device of the second group of inventions of the present application is provided with: a magnetic recording medium including a data information recording unit and a servo information unit for tracking; while detecting the servo information of the servo information unit, A magnetic head for recording and reproducing data information in the data information recording portion, wherein the data information recording portion has a data track with a data track pitch Tp, and the servo information portion is composed of a magnetic recording layer formed in a predetermined concave-convex pattern , the servo information section has a burst section for recording a burst signal for tracking, and the burst section includes a first burst area composed of a magnetic recording layer on which a plurality of convex portions of the burst signal are recorded, a second burst area, and a second burst area. The second burst area, the third burst area, the fourth burst area, the fifth burst area and the sixth burst area, the first burst area and the second burst area are configured in pairs, and each other is within the track width In the magnetic recording layer in which protrusions are formed at positions shifted by a distance of 1 track pitch (1Tp) in the direction, the third burst region and the fourth burst region are arranged in pairs, and are spaced apart from each other in the track width direction. The position staggered by the distance (1Tp) of 1 track pitch is the magnetic recording layer of the convex portion formed on the center line, and the third burst area and the fourth burst area are arranged so as to be separated from the first burst area and the second burst area. The center line of the burst area is staggered by the distance ((1/3)Tp) of the track pitch (1/3) as the center line to form the magnetic recording layer of the convex part, the fifth burst area and the sixth burst area The regions are arranged in pairs, and the magnetic recording layer of the convex portion is formed at a position offset from each other in the track width direction by a distance of 1 track pitch (1Tp) as the center line, and the fifth burst region and the sixth burst region are arranged as A magnetic recording layer in which protrusions are formed with centerlines shifted by a distance ((2/3)Tp) of (2/3) track pitches from the centerlines of the first burst region and the second burst region, respectively. , the magnetic recording layer of the convex portion has a substantial trapezoidal shape (square pyramid trapezoidal) respectively in the track width direction and the track circumferential direction, and on the trapezoidal shape in the track width direction, the surface of the convex magnetic recording layer is arranged When the corresponding upper side is W1, the lower side corresponding to the bottom surface of the convex magnetic recording layer is W2, the data track pitch of the data information recording part is Tp, and when the read width of the magnetic head is Wr, if Tp=W2, then satisfy 2W2- The conditions of W1≥Wr≥0.444W2 and 0.444W2<W1.

In addition, the magnetic recording and reproducing device of the second group of inventions of the present application is provided with: a magnetic recording medium including a data information recording unit and a servo information unit for tracking; while detecting the servo information of the servo information unit, A magnetic head for recording and reproducing data information in the data information recording portion, wherein the data information recording portion has a data track with a data track pitch Tp, and the servo information portion is composed of a magnetic recording layer formed in a predetermined concave-convex pattern , the servo information section has a burst section for recording a burst signal for tracking, and the burst section includes a first burst area composed of a magnetic recording layer on which a plurality of convex portions of the burst signal are recorded, a second burst area, and a second burst area. The second burst area, the third burst area, the fourth burst area, the fifth burst area and the sixth burst area, the first burst area and the second burst area are configured in pairs, and each other is within the track width In the magnetic recording layer in which protrusions are formed at positions shifted by a distance of 1 track pitch (1Tp) in the direction, the third burst region and the fourth burst region are arranged in pairs, and are spaced apart from each other in the track width direction. The position staggered by the distance (1Tp) of 1 track pitch is the magnetic recording layer of the convex portion formed on the center line, and the third burst area and the fourth burst area are arranged so as to be separated from the first burst area and the second burst area. The center line of the burst area is staggered by the distance ((1/3)Tp) of the track pitch (1/3) as the center line to form the magnetic recording layer of the convex part, the fifth burst area and the sixth burst area The regions are arranged in pairs, and the magnetic recording layer of the convex portion is formed at a position offset from each other in the track width direction by a distance of 1 track pitch (1Tp) as the center line, and the fifth burst region and the sixth burst region are arranged as A magnetic recording layer in which protrusions are formed with centerlines shifted by a distance ((2/3)Tp) of (2/3) track pitches from the centerlines of the first burst region and the second burst region, respectively. , the magnetic recording layer of the convex portion has a substantial trapezoidal shape (square pyramid trapezoidal) respectively in the track width direction and the track circumferential direction, and on the trapezoidal shape in the track width direction, the surface of the convex magnetic recording layer is arranged When the corresponding upper side is W1, the lower side corresponding to the bottom surface of the convex magnetic recording layer is W2, the data track pitch of the data information recording part is Tp, and the read width of the magnetic head is Wr, if Tp=W1, then 1.5W1 is satisfied ≥Wr≥0.444W1 condition.

In addition, the magnetic recording and reproducing device of the second group of inventions of the present application is provided with: a magnetic recording medium including a data information recording unit and a servo information unit for tracking; while detecting the servo information of the servo information unit, A magnetic head for recording and reproducing data information in the data information recording portion, wherein the data information recording portion has a data track with a data track pitch Tp, and the servo information portion is composed of a magnetic recording layer formed in a predetermined concave-convex pattern , the servo information section has a burst section for recording a burst signal for tracking, and the burst section includes a first burst area composed of a magnetic recording layer on which a plurality of convex portions of the burst signal are recorded, a second burst area, and a second burst area. The second burst area, the third burst area, the fourth burst area, the fifth burst area and the sixth burst area, the first burst area and the second burst area are configured in pairs, and each other is within the track width In the magnetic recording layer in which protrusions are formed at positions shifted by a distance of 1 track pitch (1Tp) in the direction, the third burst region and the fourth burst region are arranged in pairs, and are spaced apart from each other in the track width direction. The position staggered by the distance (1Tp) of 1 track pitch is the magnetic recording layer of the convex portion formed on the center line, and the third burst area and the fourth burst area are arranged so as to be separated from the first burst area and the second burst area. The center line of the burst area is staggered by the distance ((1/3)Tp) of the track pitch (1/3) as the center line to form the magnetic recording layer of the convex part, the fifth burst area and the sixth burst area The regions are arranged in pairs, and the magnetic recording layer of the convex portion is formed at a position offset from each other in the track width direction by a distance of 1 track pitch (1Tp) as the center line, and the fifth burst region and the sixth burst region are arranged as A magnetic recording layer in which protrusions are formed with centerlines shifted by a distance ((2/3)Tp) of (2/3) track pitches from the centerlines of the first burst region and the second burst region, respectively. , the magnetic recording layer of the convex portion has a substantial trapezoidal shape (square pyramid trapezoidal) respectively in the track width direction and the track circumferential direction, and on the trapezoidal shape in the track width direction, the surface of the convex magnetic recording layer is arranged When the corresponding upper side is W1, the lower side corresponding to the bottom surface of the convex magnetic recording layer is W2, the data track pitch of the data information recording part is Tp, and the read width of the magnetic head is Wr, if Tp<W1, then 1.5W1 is satisfied ≥Wr≥0.333W2 condition.

In addition, the magnetic recording and reproducing device of the second group of inventions of the present application is provided with: a magnetic recording medium including a data information recording unit and a servo information unit for tracking; while detecting the servo information of the servo information unit, A magnetic head for recording and reproducing data information in the data information recording portion, wherein the data information recording portion has a data track with a data track pitch Tp, and the servo information portion is composed of a magnetic recording layer formed in a predetermined concave-convex pattern , the servo information section has a burst section for recording a burst signal for tracking, and the burst section includes a first burst area composed of a magnetic recording layer on which a plurality of convex portions of the burst signal are recorded, a second burst area, and a second burst area. The second burst area, the third burst area, the fourth burst area, the fifth burst area and the sixth burst area, the first burst area and the second burst area are configured in pairs, and each other is within the track width In the direction of the magnetic recording layer, the convex portion is formed at the position staggered by the distance ((3/4)Tp) of the (3/4) track pitch as the center line, and the third burst area and the fourth burst area are configured as On the other hand, the magnetic recording layer of the convex portion is formed at the position staggered by the distance ((3/4) Tp) of the track pitch (3/4) in the track width direction as the center line, and the third burst area and the second burst area The four burst areas are configured to form a convex center line at a position staggered by a distance ((1/4)Tp) of the track pitch (1/4) from the center lines of the first burst area and the second burst area. part of the magnetic recording layer, the fifth burst area and the sixth burst area are arranged in pairs, and are staggered from each other by a distance of (3/4) track pitch ((3/4)Tp) in the track width direction The position is the central line to form the magnetic recording layer of the convex part, and the fifth burst area and the sixth burst area are configured to be respectively staggered from the center line of the first burst area and the second burst area (1/ 2) The position of the distance ((1/2)Tp) of the track pitch is the center line to form the magnetic recording layer of the convex portion, and the magnetic recording layer of the convex portion has a substantially trapezoidal shape in the track width direction and the track circumferential direction, respectively. Shape (square pyramid trapezoid), on the trapezoidal shape of described track width direction, set the upper side corresponding to the surface of the convex magnetic recording layer as W1, and the lower side corresponding to the bottom surface of the convex magnetic recording layer as W2. Data information recording When the data track pitch of the part is Tp and the read width of the magnetic head is Wr, if Tp>W2, the condition of 1.5W2≥Wr≥0.5W1 is satisfied.

In addition, the magnetic recording and reproducing device of the second group of inventions of the present application is provided with: a magnetic recording medium including a data information recording unit and a servo information unit for tracking; while detecting the servo information of the servo information unit, A magnetic head for recording and reproducing data information in the data information recording portion, wherein the data information recording portion has a data track with a data track pitch Tp, and the servo information portion is composed of a magnetic recording layer formed in a predetermined concave-convex pattern , the servo information section has a burst section for recording a burst signal for tracking, and the burst section includes a first burst area composed of a magnetic recording layer on which a plurality of convex portions of the burst signal are recorded, a second burst area, and a second burst area. The second burst area, the third burst area, the fourth burst area, the fifth burst area and the sixth burst area, the first burst area and the second burst area are configured in pairs, and each other is within the track width In the direction of the magnetic recording layer, the convex portion is formed at a position shifted by a distance ((3/2)Tp) of 1 track pitch as the center line. The third burst area and the fourth burst area are arranged in pairs, and In the track width direction, a position shifted by a distance of 1 track pitch ((3/2)Tp) is used as the center line to form a magnetic recording layer with protrusions, and the third burst area and the fourth burst area are arranged from The position where the centerlines of the first burst region and the second burst region are staggered by a distance ((1/2)Tp) of the track pitch (1/2) is the centerline to form a convex magnetic recording layer, the The fifth burst region and the sixth burst region are arranged as a pair, and the magnetic recording layer forms a convex portion at a position shifted from each other by a distance of 1 track pitch ((3/2)Tp) in the track width direction as the center line, At the same time, the fifth burst region and the sixth burst region are configured to be formed with the centerlines respectively offset by a distance (1Tp) of 1 track pitch from the centerlines of the first burst region and the second burst region The magnetic recording layer of the convex portion, the magnetic recording layer of the convex portion has a substantially trapezoidal shape (square pyramid trapezoidal) in the track width direction and the track circumferential direction, respectively, and on the trapezoidal shape in the track width direction, the convex When the upper side corresponding to the surface of the convex magnetic recording layer is W1, the lower side corresponding to the bottom surface of the convex magnetic recording layer is W2, the data track pitch of the data information recording part is Tp, and the read width of the magnetic head is Wr, if W1> Tp, the conditions of 1.5W2>Wr≥0.333W2 and 0.333W2<W1 are satisfied.

In addition, the magnetic recording and reproducing device of the second group of inventions of the present application is provided with: a magnetic recording medium including a data information recording unit and a servo information unit for tracking; while detecting the servo information of the servo information unit, A magnetic head for recording and reproducing data information in the data information recording portion, wherein the data information recording portion has a data track with a data track pitch Tp, and the servo information portion is composed of a magnetic recording layer formed in a predetermined concave-convex pattern , the servo information section has a burst section for recording a burst signal for tracking, and the burst section includes a first burst area composed of a magnetic recording layer on which a plurality of convex portions of the burst signal are recorded, a second burst area, and a second burst area. The second burst area, the third burst area, the fourth burst area, the fifth burst area and the sixth burst area, the first burst area and the second burst area are configured in pairs, and each other is within the track width In the direction of the magnetic recording layer, the convex portion is formed at a position staggered by a distance of 3 track pitches (3Tp) as the center line. The position staggered by the distance (3Tp) of the 3-track pitch is the magnetic recording layer of the convex portion formed on the center line, and the third burst area and the fourth burst area are arranged so as to be separated from the first burst area and the second burst area. The position where the center line of the burst area is staggered by a distance (1Tp) of 1 track pitch is the center line to form a convex magnetic recording layer. In the direction, the position staggered by the distance of 3 track pitches (3Tp) is the center line to form the magnetic recording layer of the convex part, and the fifth burst area and the sixth burst area are configured to be separated from the first burst area and the centerlines of the second burst region are respectively staggered by the distance (2Tp) of 2 track pitches as the centerline to form the magnetic recording layer of the convex portion, and the magnetic recording layer of the convex portion is in the track width direction and the track circumferential direction Each has a substantial trapezoidal shape (square pyramidal trapezoidal shape), and on the trapezoidal shape in the track width direction, the upper side corresponding to the surface of the convex magnetic recording layer is W1, and the lower side corresponding to the bottom surface of the convex magnetic recording layer is W1. When W2, the data track pitch of the data information recording portion is Tp, and the read width of the magnetic head is Wr, if W1>Tp, the condition of 1.5W2>Wr≥0.444W2 is satisfied.

In addition, the ideal form of the second group of inventions of the present application is as follows: when the height from the lower side of the convex magnetic recording layer W2 to the upper side W1 is h, it satisfies tan85°≥2h/(W2-W1)≥tan50° conditions of.

In addition, the ideal form of the second group of inventions of the present application is as follows: when W is the data track width, Wr is the magnetic readout width, and Tp is the track pitch, Wr<2Tp-W is satisfied.

Description of drawings

Fig. 1 is a schematic plan view showing the overall shape of the disk-shaped magnetic recording medium of the present invention.

FIG. 2 is a partially enlarged schematic view of a minute portion surrounded by a quadrilateral in FIG. 1 .

Fig. 3 is a sectional view showing a preferred embodiment of the magnetic recording medium of the present invention.

Fig. 4 is a sectional view showing a preferred embodiment of the magnetic recording medium of the present invention.

5 is a schematic perspective view showing the structure of a trapezoidal perpendicular magnetic recording layer.

Fig. 6 is a schematic perspective view of a magnetic recording and reproducing device.

FIG. 7 is a schematic plan view showing the structure of the burst portion and the relationship with the track pitch when M=2 and n=1.

FIG. 8 is a schematic plan view showing the structure of the burst portion and the relationship with the track pitch when M=2 and n=3.

FIG. 9 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

FIG. 10 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

FIG. 11 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

FIG. 12 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

FIG. 13 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

FIG. 14 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

FIG. 15 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 16 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

FIG. 17 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

FIG. 18 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

FIG. 19 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

FIG. 20 shows an experiment conducted to investigate the angle dependence of the trapezoidal slope of the trapezoidal pattern.

FIG. 21 shows an experiment conducted to investigate the angle dependence of the trapezoidal slope of the trapezoidal pattern.

FIG. 22 shows an experiment conducted to investigate the angle dependence of the trapezoidal slope of the trapezoidal pattern.

FIG. 23 shows an experiment conducted to investigate the angle dependence of the trapezoidal slope of the trapezoidal pattern.

FIG. 24 shows an experiment conducted to investigate the angle dependence of the trapezoidal slope of the trapezoidal pattern.

Fig. 25 is a schematic cross-sectional view taken along the arrow A-A' of Fig. 9 .

FIG. 26 is a diagram explaining the definition of "readout width Wr".

FIG. 27 is a diagram illustrating an upper limit condition of the magnetic readout width Wr.

Fig. 28 is a schematic plan view showing the overall shape of the disk-shaped magnetic recording medium of the present invention.

FIG. 29 is a partially enlarged schematic view of a minute portion surrounded by a quadrilateral in FIG. 28 .

Fig. 30 is a sectional view showing a preferred embodiment of the magnetic recording medium of the present invention.

Fig. 31 is a sectional view showing a preferred embodiment of the magnetic recording medium of the present invention.

Fig. 32 is a schematic perspective view showing the structure of a trapezoidal perpendicular magnetic recording layer.

Fig. 33 is a schematic perspective view of a magnetic recording and reproducing device.

Figure 34 shows the configuration relationship between the burst pattern pitch Bp and the data track pitch Tp in the burst part with 3 pairs (3 groups) of burst patterns, especially when M represents the logarithm of the burst pattern (Number of groups), M=3 and the relational expression between the burst pattern pitch Bp and the data track pitch Tp is expressed as the case of n=3 when Bp=(3/n)Tp.

Figure 35 shows the configuration relationship between the burst pattern pitch Bp and the data track pitch Tp in the burst part with 3 pairs (3 groups) of burst patterns, especially when M represents the logarithm of the burst pattern (Number of groups), M=3 and the relational expression between the burst pattern pitch Bp and the data track pitch Tp is expressed as the case of n=4 when Bp=(3/n)Tp.

Figure 36 shows the configuration relationship between the burst pattern pitch Bp and the data track pitch Tp in the burst part with 3 pairs (3 groups) of burst patterns, especially when M represents the logarithm of the burst pattern (number of groups), M=3, and the relational expression between the burst pattern pitch Bp and the data track pitch Tp is expressed as the case of n=2 when Bp=(3/n)Tp.

Figure 37 shows the configuration relationship between the burst pattern pitch Bp and the data track pitch Tp in the burst section with 3 pairs (3 groups) of burst patterns, especially when M represents the logarithm of the burst pattern (Number of groups), M=3 and the relational expression between the burst pattern pitch Bp and the data track pitch Tp is expressed as the case of n=1 when Bp=(3/n)Tp.

Fig. 38 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

FIG. 39 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

FIG. 40 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 41 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 42 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 43 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 44 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 45 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 46 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

FIG. 47 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 48 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 49 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

FIG. 50 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 51 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 52 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 53 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 54 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 55 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 56 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 57 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 58 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 59 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 60 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 61 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 62 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 63 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 64 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 65 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 66 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 67 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 68 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 69 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 70 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 71 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 72 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 73 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 74 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 75 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 76 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

Fig. 77 shows a specific experimental form, showing the relationship between W1, W2 and the track pitch Tp of the burst pattern for the magnetic readout width Wr, and also describes the position error signal PES at the same time.

FIG. 78 shows an experiment conducted to investigate the angle dependence of the trapezoidal slope of the trapezoidal pattern.

FIG. 79 shows an experiment conducted to investigate the angle dependence of the trapezoidal slope of the trapezoidal pattern.

FIG. 80 shows an experiment conducted to investigate the angle dependence of the trapezoidal slope of the trapezoidal pattern.

FIG. 81 shows an experiment conducted to investigate the angle dependence of the trapezoidal slope of the trapezoidal pattern.

FIG. 82 shows an experiment conducted to investigate the angle dependence of the trapezoidal slope of the trapezoidal pattern.

Fig. 83 is a schematic cross-sectional view taken along the A-A arrow in Fig. 38 .

FIG. 84 is a diagram explaining the definition of "readout width Wr".

FIG. 85 is a diagram illustrating an upper limit condition of the magnetic readout width Wr.

Detailed ways

Hereinafter, embodiments of the present invention will be described in detail.

First, the first group of inventions of the present application will be described in detail.

(1) The first group of inventions of this application

In the magnetic recording and reproducing apparatus of the present invention, a magnetic recording medium including a data information recording section and a servo information section for tracking is provided; while detecting the servo information of the servo information section, the data information is recorded in the The data information is recorded and reproduced by the magnetic head.

First, in order to understand the overall configuration of the device, a description of a schematic configuration example of a magnetic recording and reproducing device will be described with reference to FIG. 6 .

(Description of a Schematic Configuration Example of a Magnetic Recording and Reproducing Device)

Fig. 6 is a perspective view showing a schematic structure of a magnetic recording and reproducing apparatus as a preferred example of the present invention. In this figure, a disk-shaped perpendicular magnetic recording medium (discrete medium) is used as the magnetic recording medium 1 , and this medium is rotationally driven by a spindle motor 2 .

In addition, in order to read or write data to the magnetic recording medium, a magnetic head 5 for recording and reproducing is provided at the tip of a rotating arm 4 extending from the outside of the medium to the inside of the medium. The rotating arm 4 is rotated by the voice coil motor 3, and the magnetic head 5 can be positioned on a predetermined track based on, for example, a servo signal detected by the magnetic head 5 for recording and reproducing.

The magnetic head 5 for recording and reproducing includes a recording element and a reproducing element, for example, a single pole head of main magnetic pole excitation type is used as the recording element, and a GMR (Giant Magneto Resistance) head is used as the reproducing element, for example. Instead of the GMR head, a TMR (Tunneling Magneto-Resistance) head or the like may also be used.

In addition, although a perpendicular magnetic recording medium is described as a preferred example of the magnetic recording medium of the present invention, so-called longitudinal recording media can also be applied.

(Description of Magnetic Recording Media)

Hereinafter, the structure of the magnetic recording medium will be described.

1 is a schematic plan view showing the overall shape of a disk-shaped magnetic recording medium 1 used in the present invention, and FIG. 2 is a partially enlarged schematic view of a minute portion 100 surrounded by a quadrangle in FIG. 1 . 2 mainly schematically shows a servo information section 90 which is an area in which servo signals are recorded, and a data information recording section 80 which is a data track group for recording and reproduction.

FIG. 3 shows a sectional view of a preferred embodiment of the magnetic recording medium in the present invention, and FIG. 3 basically corresponds to the sectional view along the arrow α-α of FIG. 2 .

Although not shown in FIG. 1 , a plurality of data track groups for recording and reproducing are concentrically arranged and formed on the disk substrate.

In addition, a servo signal area (servo information section 90: a portion drawn radially in the figure) is formed radially outward from the center of the disc. That is, a so-called sector servo method in which the disk surface is divided into sectors is applied. In the servo information portion 90 of the magnetic recording medium, servo information is recorded by a servo track recorder.

If the structure of the servo information section 90 is described in detail, the servo information section 90 (so-called servo area) includes an ISG section 91, a SVAM section 92, a Gray code section 93, a burst section 94, and a padding section as shown in FIG. 2 . 95.

The ISG (Initial Signal Gain) part 91 is a continuous pattern provided to eliminate the influence of the magnetic properties of the magnetic film (magnetic layer) of the magnetic recording medium or the unevenness of the magnetic head suspension amount, and is continuously formed in the track radial direction. During reproduction of such an ISG section 91 by a magnetic head, the servo demodulation circuit determines a gain by automatic gain control (AGC) in order to correct output variation of the magnetic recording medium or the magnetic head. The automatic gain control (AGC) that plays such a role is turned off at the moment when the SVAM (SerVo Address Mark) section 92 existing in the servo area is detected, and the amplitude of the ISG section 91 is used to convert the reproduced amplitude existing in the burst section 94 to standardization.

In the gray code portion 93, information on each track number and sector number is recorded.

The burst portion 94 is a pattern for obtaining accurate positional information for the magnetic head to accurately track the track position. This pattern, for example, as shown in FIG. 2, is composed of a group of first burst regions 94a and second burst regions 94b arranged equidistantly across the basic center line at intervals of 2 track pitches (they form a group). pair); and a set of third burst areas 94c and fourth burst areas 94d existing at positions shifted by 1 track pitch from the set (they form a pair).

In other words, as an embodiment shown in FIG. 2 , the first burst region 94 a and the second burst region 94 b are configured as magnetic recording layers that respectively form convex portions in the track width direction with a position staggered by 2 track pitches as the center line. (Bp=2Tp; Bp represents the pitch of the burst area pattern, and Tp represents the track pitch), the 3rd burst area 94c and the 4th burst area 94d are configured to be from the first burst area 94a and the second burst The position where the center line of the region 94b is shifted by 1 track pitch is the magnetic recording layer (Bp=2Tp) in which the center line forms a convex portion. The length in the radial direction of the first burst area 94a, the second burst area 94b, the third burst area 94c, and the fourth burst area 94d is the length of 2 tracks. In the fourth burst area 94d, only the length of one track in the radial direction is described based on the paper of FIG. 2 .

In addition, as shown in the drawing, the first burst area 94a to the fourth burst area 94d are arranged in a state pattern shifted to the downstream side sequentially.

Also, in this specification, the first burst region 94a to the fourth burst region 94d are also referred to as the first burst region track (VTR1) to the fourth burst region track (VTR4), but this is synonymous. .

In addition, for the burst portion provided with 2 pairs (2 sets) of burst pattern of the present invention, the pitch of the paired burst pattern as above when Bp=2Tp and Bp=(2/3)Tp is studied The relationship between Bp and track pitch Tp will be described in detail later.

The padding portion 95 is a pattern provided to absorb the delay of the demodulation circuit system so that clock generation can be maintained while the servo demodulation circuit reproduces the servo region.

The ISG portion 91, the SVAM portion 92, and the filling portion 95 are continuously recorded in the disc radial direction. In addition, the gray code portion 93 also records at least several tracks or more in the radial direction.

Next, an example of a preferred cross-sectional structure of a magnetic recording medium will be described based on FIG. 3 . FIG. 3 can be viewed, for example, as a cross-sectional view along the α-α arrow in FIG. 2 .

As shown in Figure 3, the magnetic recording medium is provided with: a substrate 15; an orientation layer 14 formed on the substrate 15; a soft magnetic layer 11 formed on the orientation layer 14; an intermediate layer formed on the soft magnetic layer 11; layer 12 ; the perpendicular magnetic recording layer 10 corresponding to the uneven convex portion and the nonmagnetic layer 20 corresponding to the concave portion formed on the intermediate layer 12 ; and the protective layer 13 formed thereon.

As the substrate 15, a glass substrate, a NiP-coated aluminum alloy substrate, a Si substrate, or the like is suitably used. As the alignment layer 14, for example, an antiferromagnetic material such as PtMn capable of imparting a magnetic anisotropic magnetic field in the track width direction of the soft magnetic layer 11 can be used. In addition, it may be a non-magnetic alloy to control orientation.

Examples of the soft magnetic layer 11 include CoZrNb alloys, Fe-based alloys, Co-based amorphous alloys, multilayer films of soft magnetic/nonmagnetic layers, soft magnetic ferrite, and the like. In addition, a laminated structure in which a nonmagnetic layer is sandwiched between soft magnetic layers may be used.

The intermediate layer 12 is provided to control the perpendicular magnetic anisotropy and crystal grain size of the perpendicular magnetic recording layer formed on the intermediate layer, and for example, a CoTi nonmagnetic alloy is used. Alternatively, non-magnetic metals, alloys, or alloys with low magnetic permeability that serve the same purpose may be used.

As the perpendicular magnetic recording layer 10 of the convex portion, a medium containing ferromagnetic particles such as matrix-like CoPt in an oxide-based material of SiO ₂ or a CoCr-based alloy, FePt alloy, or Co/Pd-based artificial mesh-type multilayer alloy is suitable. wait. As will be described later, in the present invention, the recording layer 10 that functions as generating a servo signal has a trapezoidal shape.

As the material of the non-magnetic layer 20 of the concave portion, non-magnetic oxides such as SiO ₂ , Al ₂ O ₃ , TiO ₂ , and ferrite; nitrides such as AlN; and carbides such as SiC are used.

On the surface of the perpendicular magnetic recording layer 10 in the convex portion or the nonmagnetic layer 20 in the concave portion, a protective layer 13 such as a carbon thin film is usually formed by a CVD method or the like.

The formation of the perpendicular magnetic recording layer 10 and the non-magnetic layer 20 based on the concave-convex pattern (the formation of the so-called discrete medium), for example, after etching the perpendicular magnetic recording layer 10 with a certain thickness according to the predetermined concave-convex shape, sputtering corresponds to the etching depth. SiO ₂ , the etched recesses are filled. Then, excess deposited _SiO2 on the perpendicular magnetic recording layer 10 may be removed by oblique ion beam etching or the like while rotating the medium, thereby flattening the entire medium surface.

Also, the etching process for the formation of the perpendicular magnetic recording layer 10 and the non-magnetic layer 20 (formation of the so-called discrete medium) based on the concave-convex pattern in FIG. Etching as in the layer 11 region produces a concavo-convex pattern.

FIG. 4 shows a modified example of FIG. 3 . The difference between the embodiment in FIG. 4 and that in FIG. 3 is that when the perpendicular magnetic recording layer 10 formed to a predetermined thickness is etched in a predetermined concave-convex shape, the magnetic layer at the concave portion remains thin within a range that does not affect the magnetic properties. Both the forms of FIG. 4 and FIG. 3 are embodiments of the present invention, and the same symbols used in FIG. 4 and FIG. 3 denote the same components.

(Specification setting of the servo area (servo information section))

The gist of the present invention is: (1) can obtain the dimensional precision tolerance on the craft and reduce the manufacturing burden on the precision aspect; The burst area pattern of sending part is made 2 pairs (2 groups) burst area pattern, and each burst area pattern shape is made to respectively have the shape (square pyramid trapezoid) of substantial trapezoidal shape respectively in track width direction and track circumferential direction, When the upper side corresponding to the surface of the convex magnetic recording layer in the trapezoidal shape of the track width direction is W1, the lower side corresponding to the bottom surface of the convex magnetic recording layer is W2, the data track pitch of the data information recording part is Tp, and the read rate of the magnetic head is Tp. When the output width is Wr, the media structure can be set to satisfy a predetermined relationship. Also, in the trapezoidal shape of the perpendicular magnetic recording layer, the upper corners may be slightly depressed.

In addition, the magnetic head reading width Wr (reproduction track width of the magnetic head) of the present invention differs from the optical dimension width actually measured by SEM or the like, and is defined as follows.

That is, form a micro track sufficiently smaller than the writing track width, move the magnetic head sequentially in the track width direction, measure the cut-off track profile of the reproduced output V _out of the magnetic head, and set 1/2 of the maximum value of V _out (V _{out MAX} ) The width (so-called half-value width) of the output value (V _{out MAX} /2) is defined as "read width Wr". FIG. 26 shows a state diagram of the definition of "read width Wr".

In the 2 pairs (2 groups) of the burst region patterns of the burst portion of the present invention, each pair (each group) of the burst region pattern pitch Bp is respectively the same, each pair (each group) of the burst region pattern pitch Bp is prescribed ) Centerlines are sequentially staggered by (1/2) Bp. In addition, the data track pitch Tp of the data information recording portion and the burst pattern pitch Bp are specified at various values. In the case of the present invention, two cases of Bp=2Tp and Bp=(2/3)Tp are studied.

The gist of the present invention is: in these two cases, each burst area pattern shape is made to have the shape (quadrangular pyramid trapezoid) of substantially trapezoidal shape respectively in the track width direction and the track circumferential direction. When the upper side corresponding to the surface of the convex magnetic recording layer in the trapezoidal shape is W1, the lower side corresponding to the bottom surface of the convex magnetic recording layer is W2, the data track pitch of the above-mentioned data information recording part is Tp, and the read width of the magnetic head is Wr , the media structure can be set to satisfy the predetermined relationship.

In addition, the specification setting of the burst area pattern is considered to be easy to understand by referring to and studying the experimental results of the specific examples. Therefore, the present invention will be described below with reference to various experimental examples intersecting the examples and comparative examples.

(I) Experimental Example 1

When M=2, n=1

As shown in Fig. 2 or Fig. 7, when representing the logarithm (group number) of burst area pattern with M, M=2, is the relational expression expression Bp of burst area pattern pitch Bp and data track pitch Tp =(2/n)Tp when n=1. In other words, in the burst portion having two pairs (two sets) of burst patterns, the relationship between the burst pattern pitch Bp and the data track pitch Tp is Bp=2Tp.

In this example, the first burst region ( VTR1 ) 94 a and the second burst region ( VTR2 ) 94 b are arranged as a pair, and are formed at a position shifted by a distance (2Tp) of 2 track pitches in the track width direction as the center line. The magnetic recording layer of the convex portion.

Magnetic recording in which the third burst region (VTR3) 94c and the fourth burst region (VTR4) 94d are arranged in a pair, and a convex portion is formed at a position shifted by a distance (2Tp) of 2 track pitches in the track width direction from each other as the center line. layers, while these third burst region (VTR3) 94c and fourth burst region (VTR4) 94d are configured to The position where the line is shifted by a distance (1Tp) of 1 track pitch is the magnetic recording layer in which the convex portion is formed on the center line.

(Structure of Magnetic Recording Media)

As shown in FIG. 1, the disk surface is divided into sectors, and a servo area 90 as shown in FIG. 2 is formed in order to apply the sector servo method. That is, the ISG section 91 , the SVAM section 92 , the Gray code section 93 , the burst section 94 , and the padding section 95 are formed according to the pattern of each servo signal.

The magnetic recording layer (convex magnetic recording layer) of the convex portion of the burst portion 94 where the burst signal is recorded is a trapezoidal perpendicular magnetic recording layer as shown in FIG. 5 . The upper dimension corresponding to the convex magnetic recording layer surface is W1, the lower dimension corresponding to the convex magnetic recording layer bottom surface is W2, and the height from the lower edge W2 to the upper edge W1 is h, and W2>W1.

The convex portion in the ISG portion 91, SVAM portion 92, Gray code portion 93, and filling portion 95 other than the burst portion 94 is a strip-shaped convex portion perpendicular to the magnetic recording layer (not shown) that is long in the disk radial direction. ), configured at intervals of 1 bit.

The cross-sectional shape of medium is as shown in Figure 3, on the glass substrate 15 of mirror grinding, forms PtMn layer 15nm thickness, as orientation layer 14 (base layer 14), forms the soft magnetic layer 11 that is made of CoZrNb on it and is 200nm thickness, Further, an intermediate layer 12 made of a non-magnetic alloy CoTi is formed thereon to a thickness of 8 nm. Next, after forming the perpendicular magnetic recording layer 10 to a thickness of 15 nm thereon, an etching process of a predetermined pattern was performed in order to produce a predetermined concave-convex shape. Then, SiO ₂ is sputtered to fill the etched recess. Next, while rotating the medium filled with SiO ₂ , oblique ion beam etching was performed to remove excess SiO ₂ formed on the perpendicular magnetic recording layer 10 and planarize the surface of the medium. A protective film 13 of carbon thin film was formed thereon by the CVD method to a thickness of 1 nm, and a lubricant (Fomblin type) was applied to a thickness of 1 nm to complete a media sample. In addition, the perpendicular magnetic recording layer 10 is made of SiO ₂ containing ferromagnetic particles of CoPt in a matrix.

As a result of measuring the magnetic properties of the perpendicular magnetic recording layer with a sample vibration type magnetometer (VSM), the saturation magnetization Ms was 350 emu/cc and the residual saturation magnetization Mr was 340 emu/cc. The thickness (height) h of the perpendicular magnetic recording layer was set to 15 nm as described above.

It is assumed that the recording density of the servo signal is 130K·FRPI (Flux Reversal Per Inch). In addition, the track pitch Tp of the data region is set to 100nm which is equivalent to 254K·TPI (Track Per Inch). The width of the track (data track (DTR)) on the data region is assumed to be 70 nm.

The lengths of the upper side W1 and the lower side W2 of the trapezoidal perpendicular magnetic recording layer corresponding to the burst region pattern shown in Figure 5, when changing the etching conditions when the concave-convex structure is formed, take the value of the track pitch Tp of the data track as Based on the reference, the size was increased or decreased to form the experimental segments of various forms shown in Table 1 below. The angle formed between the trapezoidal slope and the bottom surface of the trapezoidal shape was 50° in all the experimental examples. That is, a shape satisfying tan50°=2h/(W2-W1) is made.

The form of the segment for the experiment was made into the above-mentioned form of M=2, n=1 (FIG. 7). For the pattern of the data track (DTR) 80, the first burst track (VTR1) 94a, the second burst track (VTR2) 94b, the third burst track (VTR3) 94c, the fourth burst track (VTR4) 94d, by combining the differential signals from VTR1 and VTR2 output to the head position with the differential signals from VTR3 and VTR4 to generate a precise PES signal.

In addition, as the recording magnetic head, a thin film induction head having a magnetic writing width of 80 nm was used. A giant magnetoresistance (GMR) head is used as the magnetic head for reproduction. Also, as shown in Table 1, the magnetic read width Wr of the reproducing magnetic head adopts various widths according to the relationship with other parameters (W1, W2, Tp).

The perpendicular magnetic recording medium used as the predetermined servo region and the data region after roughening is subjected to a process of magnetizing the perpendicular magnetic recording layer at the convex portion to generate a servo signal magnetic field. That is, between the magnetic poles of the electromagnet generated by the DC magnetic field of 15kOe, after setting the disk surface parallel to the magnetic pole surface, the trapezoidal perpendicular magnetic recording layers in the servo area and the data area are collectively magnetically charged to record the servo signal.

Thus, using the prepared magnetic recording medium for Experimental Example 1, an experiment of tracking control was carried out in the following manner.

That is, in the discrete track disk and the magnetic head for readout shown in Table 1 below, the track pitch Tp is used as a reference, and the position error signal PES of the combination of the size relationship of each element of W1, W2, Wr is obtained as the tracking characteristic Considering the allowable degree of variation of the linearity of the PES between adjacent track positions, the judgment of usability is shown in the table as "use level".

In addition, the relationship of W1, W2, Tp, and Tr implemented in the corresponding drawings in Table 1 is shown as a schematic drawing, so please refer to the corresponding drawings. In addition, the PES signal is also shown in the figure at the same time.

Table 1 (M=2; n=1)

The condition of Embodiment I-1 shown in Table 1 is to investigate how the position error signal PES is when the relationship between the burst pattern with respect to the magnetic readout width Wr, W1, W2, and the track pitch Tp is changed under the condition of W1>Tp. acquired by change. The corresponding diagrams of each example are Fig. 9 to Fig. 13 respectively.

As can be seen from FIGS. 9 to 13, in the range of "W1>Tp, 1.25W2>Wr≥0.5W2", the linearity of the position error detection signal is obtained, which is a level that can be used as a position error signal.

As shown in FIG. 7 , the structure when M=2 and n=1 can only consider the above-mentioned case of W1>Tp.

In addition, FIG. 25 shows a schematic cross-sectional view along the A-A arrow in FIG. 9 . The same symbols in Fig. 9 and Fig. 3 denote the same components.

(II) Experimental example 2

When M=2, n=3

As shown in Figure 8, when M represents the logarithm (number of groups) of the burst area pattern, it shows M=2, and the relational expression between the burst area pattern pitch Bp and the data track pitch Tp This is the case where n=3 when Bp=(2/n)Tp. That is, in a burst portion having two pairs (two sets) of burst patterns, the burst pattern pitch Bp is 2/3 times the data track pitch Tp (Bp=(2/3)Tp) .

In this example, as shown in FIG. 8, the first burst area (VTR1) 94a and the second burst area (VTR2) 94b are arranged in pairs, and are staggered (2/3) of the track pitch from each other in the track width direction. The position at the distance ((2/3)Tp) is the magnetic recording layer in which the convex portion is formed on the center line.

In addition, the third burst region (VTR3) 94c and the fourth burst region (VTR4) 94d are arranged as a pair, and are shifted from each other by a distance of (2/3) the track pitch ((2/3)Tp) in the track width direction. The position of the central line forms the magnetic recording layer of the convex portion, and these third burst regions (VTR3) 94c and fourth burst regions (VTR4) 94d are configured to be separated from the first burst region (VTR1) 94a and The position where the centerline of the second burst region ( VTR2 ) 94b is shifted by a distance ((1/3)Tp) of (1/3) the track pitch is the centerline to form a convex magnetic recording layer.

(Structure of Magnetic Recording Media)

The burst portion structure (M=2, n=1) of the magnetic recording medium in Experimental Example 1 above was changed to the structure in the case of M=2, n=3 (FIG. 8). Except for this, the magnetic recording medium used in Experimental Example 2 was produced in the same manner as in Experimental Example 1 above. Using the magnetic recording medium used in such Experimental Example 2, an experiment of tracking control was carried out in accordance with Experimental Example 1 above.

That is, in the discrete track disk and the read head shown in Table 2 below, the track pitch Tp is used as a reference, and the position error signal PES of the combination of the size relationship of each element of W1, W2, Wr is obtained as the tracking characteristic Whether or not the linearity of the PES is usable is shown in the table as "use level".

In addition, the relationship of W1, W2, Tp, and Tr implemented in the corresponding drawings in Table 2 is shown as a schematic drawing, so please refer to the corresponding drawings. In addition, the PES signal is also shown in the figure at the same time.

Table 2 (M=2; n=3)

The condition of Embodiment II-1 shown in Table 2 is to investigate how the position error signal PES changes when the relationship between the burst pattern of the magnetic readout width Wr, W1, W2, and the track pitch Tp is changed under the condition of Tp>W2 and obtained. The corresponding diagrams of each example are respectively Fig. 14 to Fig. 19 .

14 to 19, in the case of "Tp>W2, 1.5W2≥Wr≥0.5W1", the linearity of the position error detection signal is obtained, which is a usable level as the position error signal.

As shown in FIG. 8, the structure when M=2 and n=3 can consider the above-mentioned case of Tp>W2.

(III) Experimental Example 3

Experiments were performed on the angle dependence of trapezoidal-shaped slopes. That is, in the case of the lower limit condition Wr=0.5W1 ( FIG. 10 ) of Embodiment I-1 in Table 1 above, the angle dependence of the slope of the trapezoidal pattern was investigated.

Table 3 below shows the results of investigating the angle dependence of the trapezoidal slope of the trapezoidal pattern. 20 to 24 are diagrams showing PES when the angle θ of the slope of the trapezoidal pattern is set to 21°, 31°, 38.7°, 50°, and 85°. In Table 3, from the viewpoint of linearity, "○" is marked for the grades that can be used, and "×" is marked for the grades that are difficult to use linearly.

table 3

slope angle 21° 31° 38.7° 50° 85° Use level No (×) No (×) No (×) Yes (○) Yes (○) Corresponding to the accompanying drawings Figure 20 Figure 21 Figure 22 Figure 23 Figure 24

Based on the results in Table 3, in the trapezoidal pattern, even if the conditions are strict, the angle between the slope and the bottom of the trapezoidal structure in the track width direction is preferably at least 50° or greater. The maximum slope angle is preferably below 85°.

That is, when the height from the lower side of the convex magnetic recording layer that is W2 to the upper side that is W1 is h, preferably tan85°≥2h/(W2-W1)≥tan50°, if it is tan80°≥2h/(W2- W1)≥tan70° is more preferable.

From the above results, the effect of the present invention will become clear. That is, in the present invention, the pattern shape of the burst region on the discrete medium is set to have a substantially trapezoidal shape (square pyramidal trapezoid) in the track width direction and the track circumferential direction, respectively. The upper side corresponding to the surface of the convex magnetic recording layer is W1, the lower side corresponding to the bottom surface of the convex magnetic recording layer is W2, the data track pitch of the data information recording portion is Tp, and the read width of the magnetic head is Wr, so that the predetermined relationship is satisfied, so It is possible to provide a magnetic recording medium having a burst pattern shape capable of achieving a certain degree of dimensional accuracy tolerance in the process, reducing the manufacturing burden, and obtaining an accurate positional error signal, and a magnetic recording and reproducing device using the magnetic recording medium.

In addition, in the form in which a part of the magnetic layer remains as shown in FIG. 4 , leaving a relatively thin residual magnetic layer hardly affects the magnetic properties, so it can be considered that the lower side corresponding to the bottom surface of the convex magnetic recording layer ignoring the remaining part is W2 , apply the present invention.

In addition, the above-mentioned experimental example adheres to the condition of ensuring the linearity of the position error signal (PES), and in the actual device, the condition that the head width Wr (magnetic read width Wr) cannot directly reproduce the adjacent data track is added.

That is, when the data track width is W and the track pitch is Tp, the condition of Wr<2Tp-W is required. That is, as shown in FIG. 27, it is a condition that the magnetic read width Wr does not span two adjacent data tracks.

As described above, the first group of inventions of the present application has two pairs of burst pattern arranged on the discrete medium, and the shape of the burst pattern is made to have a substantially trapezoidal shape in the track width direction and the track circumferential direction respectively (four corners cone trapezoid), in the trapezoidal shape of the track width direction, set the upper edge corresponding to the surface of the convex magnetic recording layer as W1, the lower edge corresponding to the bottom surface of the convex magnetic recording layer as W2, and the data track pitch of the data information recording part as Tp 1. When the read width of the magnetic head is Wr, it satisfies the predetermined relationship, so it is possible to provide a magnetic head with a burst pattern shape that can obtain a certain degree of dimensional accuracy tolerance in the process, reduce the manufacturing burden, and obtain an accurate position error signal. A recording medium and a magnetic recording and reproducing apparatus using the magnetic recording medium.

Hereinafter, the second group of inventions of the present application will be described in detail.

(2) The second group of inventions of this application

In the magnetic recording and reproducing apparatus of the present invention, a magnetic recording medium including a data information recording section and a servo information section for tracking is provided; while detecting the servo information of the servo information section, the data information is recorded in the The data information is recorded and reproduced by the magnetic head.

First, in order to understand the overall configuration of the device, a schematic configuration example of a magnetic recording and reproducing device will be described with reference to FIG. 33 .

(Description of a Schematic Configuration Example of a Magnetic Recording and Reproducing Device)

Fig. 33 is a perspective view showing a schematic structure of a magnetic recording and reproducing apparatus as a preferred example of the present invention. In this figure, a disk-shaped perpendicular magnetic recording medium (discrete medium) is used as the magnetic recording medium 1 , and this medium is rotationally driven by a spindle motor 2 .

In addition, in order to read or write data to the magnetic recording medium, a magnetic head 5 for recording and reproducing is provided at the tip of a rotating arm 4 extending from the outside of the medium to the inside of the medium. The rotating arm 4 is rotated by the voice coil motor 3, and the magnetic head 5 can be positioned on a predetermined track based on, for example, a servo signal detected by the magnetic head 5 for recording and reproducing.

The magnetic head 5 for recording and reproducing includes a recording element and a reproducing element, for example, a single pole head of main magnetic pole excitation type is used as the recording element, and a GMR (Giant Magneto Resistance) head is used as the reproducing element, for example. Instead of the GMR head, a TMR (tunneling magnetoresistance) head or the like may be used.

In addition, although a perpendicular magnetic recording medium is described as a preferred example of the magnetic recording medium of the present invention, a longitudinal recording medium is also applicable.

(Description of Magnetic Recording Media)

Hereinafter, the structure of the magnetic recording medium will be described.

FIG. 28 is a schematic plan view showing the overall shape of the disk-shaped magnetic recording medium 1 used in the present invention, and FIG. 29 is a partial enlarged schematic view of a minute portion 100 surrounded by a quadrangle in FIG. 28 . FIG. 29 mainly shows a servo information section 90 which is an area where servo signals are recorded, and a data information recording section 80 which is a data track group for recording and reproducing.

FIG. 30 is a cross-sectional view showing a preferred embodiment of the magnetic recording medium in the present invention, and FIG. 30 basically corresponds to the cross-sectional view along the arrow α-α of FIG. 29 .

Although not shown in FIG. 28, a plurality of data track groups for recording and reproducing are arranged on the disk substrate to form concentric circles.

In addition, a servo signal area (servo information portion 90: a portion drawn radially in the figure) is formed radially from the center of the disk to the outside. That is, a so-called sector servo method in which the disk surface is divided into sectors is applied. In the servo information portion 90 of the magnetic recording medium, servo information is recorded by a servo track recorder.

If the structure of the servo information section 90 is described in detail, the servo information section 90 (so-called servo area) includes an ISG section 91, a SVAM section 92, a Gray code section 93, a burst section 94, and a padding section as shown in FIG. 2 . 95.

The ISG (Initial Signal Gain) part 91 is a continuous pattern provided to eliminate the influence of the magnetic properties of the magnetic film (magnetic layer) of the magnetic recording medium or the unevenness of the magnetic head suspension amount, and is continuously formed in the track radial direction. During reproduction of such an ISG section 91 by a magnetic head, the servo demodulation circuit determines a gain based on automatic gain control (AGC) for correcting the output variation of the magnetic recording medium or the magnetic head. The automatic gain control (AGC) that plays such a role is turned off at the moment when the SVAM (SerVo Address Mark) section 92 existing in the servo area is detected, and the amplitude of the ISG section 91 is used to convert the reproduced amplitude existing in the burst section 94 to standardization.

In the gray code portion 93, information on each track number and sector number is recorded.

The burst portion 94 is a pattern for obtaining accurate positional information for the magnetic head to accurately track the track position. This pattern, for example, as shown in FIG. 29, is composed of a group of first burst regions 94a and second burst regions 94b arranged equidistantly on the center line limiting the pitch of adjacent tracks, respectively (they into a pair); a group of the third burst area 94c and the fourth burst area 94d respectively present at positions staggered (1/3) and (2/3) of the track pitch from the group (they form a pair); And a set of the fifth burst area 94e and the sixth burst area 94f (they form a pair).

In other words, as an embodiment shown in FIG. 29 , the first burst region 94a and the second burst region 94b are configured to form convex portions in the track width direction with a position staggered by 1 track pitch as the center line for magnetic recording. Layer (the pitch Bp=track pitch Tp of burst pattern), the 3rd burst region 94c and the 4th burst region 94d are configured to be from the center line of the first burst region 94a and the second burst region 94b The position of the staggered (1/3) track pitch is the magnetic recording layer (Bp=Tp) of the convex portion formed on the central line, and the fifth burst area 94e and the sixth burst area 94f are configured to be separated from the first burst area 94a The position shifted (2/3) of the track pitch from the centerline of the second burst region 94b is the magnetic recording layer (Bp=Tp) where the convex portion is formed on the centerline.

In addition, as shown in the drawing, the first burst area 94a to the sixth burst area 94f are patterned in a state of being shifted sequentially on the downstream side.

Also, in this specification, the first burst region 94a to the sixth burst region 94f are also referred to as the first burst region track (VTR1) to the sixth burst region track (VTR6), but this is synonymous. .

In addition, for the burst portion provided with 3 pairs (3 groups) of the burst pattern of the present invention, it is not limited to the situation where the pitch Bp of the paired burst pattern is consistent with the track pitch Tp as described above, and may be other forms. For all forms, details will be given later.

The padding portion 95 is a pattern provided to absorb the delay of the demodulation circuit system so that clock generation can be maintained while the servo demodulation circuit reproduces the servo region.

The ISG portion 91, the SVAM portion 92, and the filling portion 95 are continuously recorded in the disc radial direction. In addition, the gray code portion 93 also records at least several tracks or more in the radial direction.

Next, an example of a preferred cross-sectional structure of a magnetic recording medium will be described based on FIG. 30 . FIG. 30 can be viewed as a sectional view along the α-α arrow in FIG. 29 , for example.

As shown in Figure 30, the magnetic recording medium is provided with: a substrate 15; an orientation layer 14 formed on the substrate 15; a soft magnetic layer 11 formed on the orientation layer 14; an intermediate layer formed on the soft magnetic layer 11; layer 12 ; the perpendicular magnetic recording layer 10 corresponding to the uneven convex portion and the nonmagnetic layer 20 corresponding to the concave portion formed on the intermediate layer 12 ; and the protective layer 13 formed thereon.

As the substrate 15, a glass substrate, a NiP-coated aluminum alloy substrate, a Si substrate, or the like is suitably used. As the alignment layer 14, for example, an antiferromagnetic material such as PtMn capable of imparting a magnetic anisotropic magnetic field in the track width direction of the soft magnetic layer 11 can be used. In addition, it may be a non-magnetic alloy to control orientation. In addition, a laminated structure in which a nonmagnetic layer is sandwiched between soft magnetic layers may be used.

Examples of the soft magnetic layer 11 include CoZrNb alloys, Fe-based alloys, Co-based amorphous alloys, multilayer films of soft magnetic/nonmagnetic layers, soft magnetic ferrite, and the like.

The intermediate layer 12 is provided to control the perpendicular magnetic anisotropy and crystal grain size of the perpendicular magnetic recording layer formed on the intermediate layer, and for example, a CoTi nonmagnetic alloy is used. Alternatively, non-magnetic metals, alloys, or alloys with low magnetic permeability that serve the same purpose may be used.

As the perpendicular magnetic recording layer 10 of the convex portion, a medium containing ferromagnetic particles such as CoPt in a matrix in a _SiO2 oxide-based material, or a CoCr-based alloy, FePt alloy, or Co/Pd-based artificial mesh-type multilayer alloy is suitably used. wait. As will be described later, in the present invention, the recording layer 10 that functions as generating a servo signal has a trapezoidal shape.

As the material of the non-magnetic layer 20 of the concave portion, non-magnetic oxides such as SiO ₂ , Al ₂ O ₃ , TiO ₂ , and ferrite; nitrides such as AlN; and carbides such as SiC are used.

On the surface of the perpendicular magnetic recording layer 10 in the convex portion or the nonmagnetic layer 20 in the concave portion, a protective layer 13 such as a carbon thin film is usually formed by a CVD method or the like.

The formation of the perpendicular magnetic recording layer 10 and the non-magnetic layer 20 based on the concave-convex pattern (the formation of the so-called discrete medium), for example, after etching the perpendicular magnetic recording layer 10 with a certain thickness according to the predetermined concave-convex shape, sputtering corresponds to the etching depth. SiO ₂ , the etched recesses are filled. Then, excess deposited _SiO2 on the perpendicular magnetic recording layer 10 may be removed by oblique ion beam etching or the like while rotating the medium, thereby flattening the entire medium surface.

In addition, the etching process for the formation of the perpendicular magnetic recording layer 10 and the nonmagnetic layer 20 (formation of the so-called discrete medium) based on the concave-convex pattern in FIG. Etching as in the layer 11 region produces a concavo-convex pattern.

FIG. 31 shows a modified example of FIG. 30 . The difference between the embodiment of FIG. 31 and that of FIG. 30 is that when the perpendicular magnetic recording layer 10 formed with a predetermined thickness is etched in a predetermined concave-convex shape, the magnetic layer at the concave portion remains thin within the range that does not affect the magnetic properties. The forms of Fig. 31 and Fig. 30 are both embodiments of the present invention, and the same symbols used in Fig. 31 and Fig. 30 represent the same components.

(Specification setting of the servo area (servo information section))

The main points of the present invention are: (1) the dimensional accuracy tolerance in the process can be obtained and the manufacturing burden on the accuracy can be reduced; (2) the accurate position error signal for tracking can be obtained; and (3) the accurate position can be obtained by expanding The practical range of the error signal and the purpose of expanding the allowable range of the device design are to make the burst pattern of the burst part on the servo area of the discrete medium into 3 pairs (3 groups) of burst patterns, and at the same time make each burst pattern The pattern shape is made into a substantially trapezoidal shape (square pyramidal trapezoidal shape) in the track width direction and the track circumferential direction respectively. When the upper side of the trapezoidal shape in the track width direction corresponds to the surface of the convex magnetic recording layer is W1, and the upper side corresponding to the convex magnetic recording layer is When the lower side corresponding to the bottom surface of the magnetic recording layer is W2, the data track pitch of the data information recording part is Tp, and the read width of the magnetic head is Wr, the medium structure can be set to satisfy the predetermined relationship. Also, in the trapezoidal shape of the perpendicular magnetic recording layer, the upper corners may be slightly depressed.

In addition, the magnetic head reading width Wr (reproduction track width of the magnetic head) of the present invention differs from the optical dimension width actually measured by SEM or the like, and is defined as follows.

That is, form a micro track sufficiently smaller than the writing track width, move the magnetic head sequentially in the track width direction, measure the cut-off track profile of the reproduced output V _out of the magnetic head, and set 1/2 of the maximum value of V _out (V _{out MAX} ) The width (so-called half-value width) of the output value (V _{out MAX} /2) is defined as "read width Wr". FIG. 84 shows a state diagram of the definition of "read width Wr".

In the 3 pairs (3 groups) of the burst region patterns of the burst portion of the present invention, each pair (each group) of the burst region pattern pitch Bp is respectively the same, each pair (each group) of the burst region pattern pitch Bp is prescribed ) Centerlines are sequentially staggered by (1/3) Bp. In addition, the data track pitch Tp of the data information recording portion and the burst pattern pitch Bp are specified at various values. In the case of the present invention, four cases of Bp=Tp, Bp=(3/4)Tp, Bp=(3/2)Tp, and Bp=3Tp were studied.

The gist of the present invention is: in these four kinds of cases, each burst area pattern shape is made to have the shape (quadrangular pyramid trapezoid) of substantially trapezoidal shape respectively on track width direction and track circumferential direction, when setting the track width direction When the upper side corresponding to the surface of the convex magnetic recording layer in the trapezoidal shape is W1, the lower side corresponding to the bottom surface of the convex magnetic recording layer is W2, the data track pitch of the above-mentioned data information recording part is Tp, and the read width of the magnetic head is Wr , the media structure can be set to satisfy the predetermined relationship.

In addition, the specification setting of the burst area pattern is considered to be easy to understand by referring to and studying the experimental results of the specific examples. Therefore, the present invention will be described below with reference to various experimental examples intersecting the examples and comparative examples.

(1) Experimental example 2-1

When M=3, n=3

As shown in Fig. 29 or Fig. 34, when representing the logarithm (number of groups) of burst area pattern with M, M=3, is to express the relational expression Bp of burst area pattern pitch Bp and data track pitch Tp =(3/n)Tp when n=3. In other words, it is the case where the burst pattern pitch Bp is the same as the data track pitch Tp (Bp=Tp) in the burst portion having three pairs (three sets) of burst pattern.

In this example, the first burst region ( VTR1 ) 94 a and the second burst region ( VTR2 ) 94 b are arranged as a pair, and are formed at a position shifted by a distance (1Tp) of 1 track pitch from each other in the track width direction as the center line. The magnetic recording layer of the convex portion.

Magnetic recording in which the third burst region (VTR3) 94c and the fourth burst region (VTR4) 94d are arranged in a pair, and a convex portion is formed at a position shifted by a distance (1Tp) of 1 track pitch in the track width direction from each other as the center line. layers, while these third burst region (VTR3) 94c and fourth burst region (VTR4) 94d are configured to The position where the line is shifted by a distance ((1/3)Tp) of (1/3) the track pitch is the magnetic recording layer in which the convex portion is formed on the center line.

Magnetic recording in which the fifth burst region (VTR5) 94e and the sixth burst region (VTR6) 94f are arranged in a pair, and a convex portion is formed at a position shifted by a distance (1Tp) of 1 track pitch from each other in the track width direction as the center line. layers, while these fifth burst region (VTR5) 94e and sixth burst region (VTR6) 94f are configured to The position where the line is shifted by a distance ((2/3)Tp) of (2/3) the track pitch is the magnetic recording layer in which the convex portion is formed on the center line.

(Structure of Magnetic Recording Media)

As shown in FIG. 28, the disk surface is divided into sectors, and a servo area 90 as shown in FIG. 29 is formed in order to apply the sector servo method. That is, the ISG section 91 , the SVAM section 92 , the Gray code section 93 , the burst section 94 , and the padding section 95 are formed according to the pattern of each servo signal.

The magnetic recording layer (convex magnetic recording layer) of the convex portion of the burst portion 94 where the burst signal is recorded is a trapezoidal perpendicular magnetic recording layer as shown in FIG. 32 . The upper dimension corresponding to the convex magnetic recording layer surface is W1, the lower dimension corresponding to the convex magnetic recording layer bottom surface is W2, and the height from the lower edge W2 to the upper edge W1 is h, and W2>W1.

The convex portion in the ISG portion 91, SVAM portion 92, Gray code portion 93, and filling portion 95 other than the burst portion 94 is a strip-shaped convex portion perpendicular to the magnetic recording layer (not shown) that is long in the disk radial direction. ), configured at intervals of 1 bit.

The cross-sectional shape of the medium is shown in Figure 30. On the mirror-polished glass substrate 15, a PtMn layer with a thickness of 15nm is formed as an orientation layer 14 (base layer 14), and a soft magnetic layer 11 with a thickness of 200nm made of CoZrNb is formed thereon. , and an 8 nm-thick intermediate layer 12 made of a non-magnetic alloy CoTi is formed thereon. Next, after forming the perpendicular magnetic recording layer 10 with a thickness of 15 nm thereon, an etching process of a predetermined pattern was carried out in order to produce a predetermined concave-convex shape. SiO ₂ is then sputtered to fill the etched recesses. Next, while rotating the medium filled with SiO ₂ , oblique ion beam etching was performed to remove excess SiO ₂ formed on the perpendicular magnetic recording layer 10 and planarize the surface of the medium. A protective film 13 of carbon thin film with a thickness of 1 nm was formed thereon by CVD, and a lubricant (Fomblin type) was coated with a thickness of 1 nm to complete a media sample. In addition, the perpendicular magnetic recording layer 10 is made of SiO ₂ containing ferromagnetic particles of CoPt in a matrix.

As a result of measuring the magnetic properties of the perpendicular magnetic recording layer with a sample vibration type magnetometer (VSM), the saturation magnetization Ms was 350 emu/cc and the residual saturation magnetization Mr was 340 emu/cc. The thickness (height) h of the perpendicular magnetic recording layer was set to 15 nm as described above.

It is assumed that the recording density of the servo signal is 130K·FRPI (Flux Reversal Per Inch). In addition, the track pitch Tp of the data region is set to 100nm which is equivalent to 254K·TPI (Track Per Inch). The width of the track (data track (DTR)) on the data region is assumed to be 70 nm.

The lengths of the upper side W1 and the lower side W2 of the trapezoidal perpendicular magnetic recording layer corresponding to the burst pattern shown in FIG. A standard, from which the size is increased or decreased to form the experimental segments of various forms shown in Table 2-1 below. The angle formed between the trapezoidal slope and the bottom surface of the trapezoidal shape was 50° in all the experimental examples. That is, a shape satisfying tan50°=2h/(W2-W1) is made.

The above-mentioned form of M=3, n=3 was made into the form of the segment for the experiment (FIG. 34). For the pattern of the data track (DTR) 80, the first burst track (VTR1) 94a, the second burst track (VTR2) 94b, the third burst track (VTR3) 94c, the fourth burst track (VTR4) 94d, the fifth burst track (VTR5) 94e, and the sixth burst track (VTR6) 94f, by outputting the differential signal from VTR1 and VTR2, the differential signal from VTR3 and VTR4, and The differential signals from VTR5 and VTR6 are synthesized to generate a precise PES signal.

As the magnetic head for recording, a thin film induction head with a magnetic writing width of 80 nm was used. A giant magnetoresistance (GMR) head is used as the magnetic head for playback. In addition, as shown in Table 2-1, various widths are used for the magnetic read width Wr of the reproducing magnetic head in accordance with the relationship with other parameters (W1, W2, Tp).

The perpendicular magnetic recording medium used as the predetermined servo region and the data region after roughening is subjected to a process of magnetizing the perpendicular magnetic recording layer at the convex portion to generate a servo signal magnetic field. That is, between the magnetic poles of the electromagnet generating a DC magnetic field of 15 kOe, after setting the disk surface parallel to the magnetic pole surface, the trapezoidal perpendicular magnetic recording layers in the servo area and the data area were collectively magnetically magnetized to record the servo signal.

Thus, using the prepared magnetic recording medium for Experimental Example 2-1, an experiment of tracking control was carried out in the following manner.

That is, in the discrete track disk and read head shown in Table 2-1 below, the track pitch Tp is used as a reference to obtain all the position error signals PES of the combination of the magnitude relationship of each element of W1, W2, Wr, as The tracking characteristic considers the allowable degree of variation of the linearity of the PES between adjacent track positions, and the judgment of usability is shown in the table as "use level".

The relationship of W1, W2, Tp, and Tr implemented in the corresponding drawings in Table 2-1 is shown as a schematic drawing, so please refer to the corresponding drawings. The PES signal is also shown in the figure at the same time.

Table 2-1 (M=3; n=3)

(1) The condition of Embodiment 2-I-1 shown in Table 2-1 is that under the condition of Tp>W2, investigate the effect of changing the burst region pattern on the magnetic readout width Wr and W1, W2 and track pitch Tp It is obtained by how the position error signal PES changes during the relationship. The corresponding diagrams of each example are Fig. 38 to Fig. 43, respectively.

From Figure 38 to Figure 43, it can be seen that in the range of "Tp>W2, 2W2>Wr≥0.5W2 and 0.5W2<W1", the linearity of the position error detection signal is obtained, and it is a level that can be used as a position error signal .

In addition, it can be seen from these figures that under the condition of "Tp>W2 and Wr=0.5W2", the so-called geometry does not have complete linearity, but because there are isolation zones of discrete orbits, it becomes an allowable PES that can be used as a PES. level.

In addition, FIG. 84 shows a schematic cross-sectional view along the A-A arrow in FIG. 38 . The same symbols in Fig. 38 and Fig. 30 denote the same members.

(2) In addition, in Embodiment 2-I-2 shown in Table 2-1, under the condition of W2=Tp, the position error signal PES was investigated when the relationship between the burst pattern and W1, W2 with respect to the magnetic readout width Wr was changed. how to change. The corresponding diagrams of each example are Fig. 44 to Fig. 48, respectively.

From Figure 44 to Figure 48, in the case of "Tp = W2, 2W2-W1≥Wr≥0.444W2 and 0.444W2<W1", the linearity of the position error detection signal can be obtained, and as the position error signal, it can be used level.

(3) In addition, in Embodiment 2-I-3 shown in Table 2-1, under the condition of W1=Tp, the position error signal PES was investigated when the relationship between the burst pattern and W1, W2 with respect to the magnetic readout width Wr was changed. how to change. The corresponding diagrams of each example are Fig. 49 to Fig. 54, respectively.

As can be seen from Fig. 49 to Fig. 54, in the range of "Tp = W1, 1.5W1≥Wr≥0.444W1", the linearity of the position error detection signal is obtained, which is a level that can be used as a position error signal.

(4) In addition, in Embodiment 2-I-4 shown in Table 2-1, under the condition of W1>Tp, the position error when changing the relationship between the burst region pattern and W1, W2 and Tp with respect to the magnetic readout width Wr was investigated. How the signal PES changes. The corresponding diagrams of each example are Fig. 55 to Fig. 60, respectively.

From Fig. 55 to Fig. 60, it can be seen that in the range of "Tp<W1, 1.5W1≥Wr≥0.333W2", the linearity of the position error detection signal is obtained, which is a level that can be used as a position error signal.

Also, under the condition of W1>Tp in Embodiment 2-I-4, no PES signal can be obtained when Wr=1.5W2. Therefore, this embodiment does not perform display based on drawings.

(II) Experimental example 2-2

When M=3, n=4

As shown in Figure 35, when M represents the logarithm (number of groups) of the burst pattern, M=3 is shown, and the relational expression between the burst pattern pitch Bp and the data track pitch Tp is expressed This is the case where n=4 when Bp=(3/n)Tp. That is, in a burst portion having three pairs (three sets) of burst patterns, the burst pattern pitch Bp is 3/4 times the data track pitch Tp (Bp=(3/4)Tp) .

In this example, as shown in FIG. 35, the first burst area (VTR1) 94a and the second burst area (VTR2) 94b are arranged in pairs, and are staggered (3/4) of the track pitch from each other in the track width direction. The position at the distance ((3/4)Tp) is the magnetic recording layer in which the convex portion is formed on the center line.

In addition, the third burst region (VTR3) 94c and the fourth burst region (VTR4) 94d are arranged in a pair, and are shifted from each other by a distance of (3/4) track pitch ((3/4)Tp) in the track width direction. The position of the central line forms the magnetic recording layer of the convex portion, and these third burst regions (VTR3) 94c and fourth burst regions (VTR4) 94d are configured to be separated from the first burst region (VTR1) 94a and The position where the centerline of the second burst region ( VTR2 ) 94b is shifted by a distance ((1/4)Tp) of (1/4) track pitch is the centerline to form a convex magnetic recording layer.

The fifth burst region (VTR5) 94e and the sixth burst region (VTR6) 94f are arranged in a pair, and are positioned at a distance ((3/4)Tp) of (3/4) the track pitch from each other in the track width direction. The magnetic recording layer of the convex portion is formed for the center line, and these fifth burst region (VTR5) 94e and sixth burst region (VTR6) 94f are configured to be separated from the first burst region (VTR1) 94a and the second burst region (VTR1) 94a and the second The position where the center line of the burst region ( VTR2 ) 94b is shifted by a distance ((1/2)Tp) of (1/2) the track pitch is the center line to form a convex magnetic recording layer.

(Structure of Magnetic Recording Media)

The burst portion structure (M=3, n=3) of the magnetic recording medium in Experimental Example 2-1 above was changed to the structure in the case of M=3, n=4 (FIG. 35). In addition, a magnetic recording medium used in Experimental Example 2-2 was produced in the same manner as in Experimental Example 2-1 above. Using the magnetic recording medium used in Experimental Example 2-1, an experiment of tracking control was carried out as in Experimental Example 1 above.

That is, in the following table 2-2, in the discrete track disk and the magnetic head for reading, the track pitch Tp is used as the reference, and all the position error signals PES of the combination of the magnitude relationship of the elements of W1, W2, and Wr are obtained as In the tracking characteristic, whether or not the linearity of the PES is usable is shown in a table as "use level".

In addition, the relationship of W1, W2, Tp, and Tr implemented in the corresponding drawings in Table 2-2 is shown as a schematic diagram, so please refer to the corresponding drawings. In addition, the PES signal is also shown in the figure at the same time.

Table 2-2 (M=3; n=4)

(1) The condition of Embodiment 2-II-1 shown in Table 2-2 is that under the condition of Tp>W2, investigate the effect of changing the burst region pattern on the magnetic readout width Wr and W1, W2 and track pitch Tp It is obtained by how the position error signal PES changes during the relationship. The corresponding diagrams of each example are Fig. 61 to Fig. 68, respectively.

From Fig. 61 to Fig. 68, it can be seen that in the range of "Tp>W2, 1.5W2≥Wr≥0.5W1", the linearity of the position error detection signal can be obtained, which can be used as a position error signal.

As shown in FIG. 35, the above-mentioned case of Tp>W2 can be considered for the structure when M=3 and n=4.

(III) Experimental example 2-3

When M=3, n=2

As shown in Figure 36, when M represents the logarithm (number of groups) of the burst pattern, M=3 is shown, and the relational expression between the burst pattern pitch Bp and the data track pitch Tp is expressed This is the case where n=2 when Bp=(3/n)Tp. In other words, in the burst portion having 3 pairs (3 sets) of burst pattern, when the burst pattern pitch Bp is 3/2 times the data track pitch Tp (Bp=(3/2)Tp) .

In this example, as shown in FIG. 36, the first burst area (VTR1) 94a and the second burst area (VTR2) 94b are arranged in pairs, and are staggered (3/2) of the track pitch from each other in the track width direction. The position at the distance ((3/2)Tp) is the magnetic recording layer where the convex portion is formed on the center line.

In addition, the third burst region (VTR3) 94c and the fourth burst region (VTR4) 94d are arranged in a pair, and are shifted from each other by a distance of (3/2) track pitch ((3/2)Tp) in the track width direction. The position of the central line forms the magnetic recording layer of the convex portion, and these third burst regions (VTR3) 94c and fourth burst regions (VTR4) 94d are configured to be separated from the first burst region (VTR1) 94a and The position where the center line of the second burst region ( VTR2 ) 94b is shifted by a distance ((1/2)Tp) of (1/2) track pitch is the center line to form a convex magnetic recording layer.

The fifth burst region (VTR5) 94e and the sixth burst region (VTR6) 94f are arranged in a pair, and are positioned at a distance ((3/2)Tp) of (3/2) the track pitch from each other in the track width direction. The magnetic recording layer of the convex portion is formed for the center line, and these fifth burst region (VTR5) 94e and sixth burst region (VTR6) 94f are configured to be separated from the first burst region (VTR1) 94a and the second burst region (VTR1) 94a and the second The position where the center line of the burst region ( VTR2 ) 94b is shifted by a distance (1Tp) of 1 track pitch is the center line to form a convex magnetic recording layer.

(Structure of Magnetic Recording Media)

The burst portion structure (M=3, n=3) of the magnetic recording medium in Experimental Example 2-1 above was changed to the structure in the case of M=3, n=2 (FIG. 36). Except for this, the magnetic recording medium used in Experimental Example 2-3 was produced in the same manner as in Experimental Example 2-1 above. Using the magnetic recording medium used in this experimental example 2-3, an experiment of tracking control was carried out in accordance with the above-mentioned experimental example 2-1.

That is, in the discrete track disk and the magnetic head for readout shown in the following Table 2-3, with the track pitch Tp as the reference, all the position error signals PES of the combination of the magnitude relationship of the elements of W1, W2, and Wr are obtained as In the tracking characteristic, whether or not the linearity of the PES is usable is shown in a table as "use level".

In addition, the relationship between W1, W2, Tp, and Tr implemented in the corresponding drawings in Table 2-3 is shown as a schematic diagram, so please refer to the corresponding drawings. In addition, the PES signal is also shown in the figure at the same time.

Table 2-3 (M=3; n=2)

(1) The condition of Embodiment 2-III-1 shown in Table 2-3 is that under the condition of W1>Tp, investigate the effect of changing the burst region pattern on the magnetic readout width Wr and W1, W2 and track pitch Tp It is obtained by how the position error signal PES changes during the relationship. The corresponding diagrams of each example are Fig. 67 to Fig. 72, respectively.

From Figure 67 to Figure 72, it can be seen that in the range of "W1>Tp, 1.5W2>Wr≥0.333W2 and 0.333W2<W1", the linearity of the position error detection signal can be obtained, which can be used as the position error signal grade.

As shown in FIG. 36, the above-mentioned case of W1>Tp can be considered for the structure when M=3 and n=2.

(IV) Experimental example 2-4

When M=3, n=1

As shown in Figure 37, when M is used to represent the logarithm (group number) of the burst pattern, M=3, and the relational expression between the burst pattern pitch Bp and the data track pitch Tp is expressed This is the case where n=1 when Bp=(3/n)Tp. In other words, in a burst portion having three pairs (three sets) of burst patterns, the burst pattern pitch Bp is three times the data track pitch Tp (Bp=3Tp).

In this example, as shown in FIG. 37 , the first burst region ( VTR1 ) 94 a and the second burst region ( VTR2 ) 94 b are arranged in pairs, and are shifted by a distance of 3 track pitches (3Tp) in the track width direction. The position of the centerline forms a convex portion of the magnetic recording layer.

In addition, the third burst region ( VTR3 ) 94 c and the fourth burst region ( VTR4 ) 94 d are arranged in a pair, and a convex portion is formed at a position shifted by a distance (3Tp) of 3 track pitches from each other in the track width direction. magnetic recording layer, while these third burst area (VTR3) 94c and fourth burst area (VTR4) 94d are configured to A magnetic recording layer in which a protrusion is formed at a position where the center line of the center line is shifted by a distance (1Tp) of 1 track pitch is the center line.

Magnetic recording in which the fifth burst region (VTR5) 94e and the sixth burst region (VTR6) 94f are arranged in a pair, and a convex portion is formed at a position shifted by a distance (3Tp) of 3 track pitches in the track width direction from each other. layer, while the fifth burst region (VTR5) 94e and the sixth burst region (VTR6) 94f are configured to The position where the line is shifted by a distance (2Tp) of 2 track pitches is the magnetic recording layer in which the convex portion is formed on the center line.

(Structure of Magnetic Recording Media)

The burst portion structure (M=3, n=3) of the magnetic recording medium in the above-mentioned Experimental Example 2-1 was changed to the structure in the case of the above-mentioned M=3, n=1 (FIG. 37). Except for this, the magnetic recording medium used in Experimental Example 2-4 was produced in the same manner as in Experimental Example 2-1 above. Using the magnetic recording medium used in this experimental example 2-4, an experiment of tracking control was carried out according to the above-mentioned experimental example 2-1.

That is, in the discrete track disk and the magnetic head for readout shown in the following Tables 2-4, with the track pitch Tp as the reference, all the position error signals PES of the combination of the size relationship of the elements of W1, W2, and Wr are obtained as In the tracking characteristic, whether or not the linearity of the PES is usable is shown in a table as "use level".

In addition, the relationship between W1, W2, Tp, and Tr implemented in the corresponding drawings in Tables 2-4 is shown in the form of a schematic drawing, so please refer to the corresponding drawings. In addition, the PES signal is also shown in the figure at the same time. In addition, although a plurality of patterns are arranged on the actual segment track, one burst pattern is shown in the pattern diagram for easy understanding.

Table 2-4 (M=3; n=1)

(1) The condition of Embodiment 2-IV-1 shown in Table 2-4 is that under the condition of W1>Tp, investigate the effect of changing the burst region pattern on the magnetic readout width Wr and W1, W2 and track pitch Tp It is obtained by how the position error signal PES changes during the relationship. The corresponding diagrams of each example are Fig. 73 to Fig. 77, respectively.

From Fig. 73 to Fig. 77, it can be seen that in the range of "W1>Tp, 1.5W2>Wr≥0.444W2", the linearity of the position error detection signal is obtained, which is a level that can be used as a position error signal.

As shown in FIG. 37, the above-mentioned case of W1>Tp can be considered for the configuration when M=3 and n=1.

(V) Experimental example 2-5

Experiments were performed on the angle dependence of trapezoidal-shaped slopes. That is, in the case of the lower limit condition Wr=0.444W1 ( FIG. 50 ) of Embodiment 2-I-3 in Table 2-1 above, the angle dependence of the slope of the trapezoidal pattern was investigated. The requirement of Wr=0.444W1 in Embodiment 2-I-3 ( FIG. 50 ) is a strict condition for obtaining linearity.

The results of investigating the angle dependence of the trapezoidal slope of the trapezoidal pattern are shown in Tables 2-5 below. 78 to 82 are diagrams showing PES when the angle θ of the slope of the trapezoidal pattern is set to 21°, 31°, 38.7°, 50°, and 85°. In Table 2-5, from the viewpoint of linearity, "○" is marked for the grades that can be used, and "×" is marked for those that are difficult to use linearly.

Table 2-5

slope angle 21° 31° 38.7° 50° 85° Use level No (×) No (×) No (×) Yes (○) Yes (○) Corresponding to the accompanying drawings Figure 78 Figure 79 Figure 80 Figure 81 Figure 82

Based on the results in Tables 2-5, when conditions are strict for trapezoidal patterns, especially the angle between the slope and the bottom of the trapezoidal structure in the track width direction is preferably at least 50° or greater. The maximum slope angle is preferably below 85°.

That is, when the height from the lower side of the convex magnetic recording layer that is W2 to the upper side that is W1 is h, preferably tan85°≥2h/(W2-W1)≥tan50°, if it is tan80°≥2h/(W2- W1)≥tan70° is more preferable.

From the above results, the effect of the present invention will become clear. That is, in the present invention, the pattern shape of the burst region on the discrete medium is set to have a substantially trapezoidal shape (square pyramidal trapezoid) in the track width direction and the track circumferential direction, respectively, and the trapezoidal shape in the track width direction is set to be the same as The upper side corresponding to the surface of the convex magnetic recording layer is W1, the lower side corresponding to the bottom surface of the convex magnetic recording layer is W2, the data track pitch of the data information recording part is Tp, and the read width of the magnetic head is Wr, so that the predetermined relationship is satisfied, so It is possible to provide a magnetic recording medium having a burst pattern shape which allows a certain degree of dimensional accuracy tolerance in the process, reduces the manufacturing burden, and obtains an accurate positional error signal, and a magnetic recording and reproducing device using the magnetic recording medium.

In addition, in the form in which a part of the magnetic layer remains as shown in FIG. 31 , leaving a relatively thin residual magnetic layer hardly affects the magnetic properties, so it can be considered that the lower side corresponding to the bottom surface of the convex magnetic recording layer ignoring the remaining part is W2 , apply the present invention.

Even if a pair of burst pattern patterns is added to make a total of 4 pairs of burst pattern patterns (M=4), the practical range for obtaining accurate position error signals can be expanded. But at this time, compared with the need for more complicated manufacturing process and control, the expansion effect of its practical range becomes a saturated state. Compared with the present invention application for a total of 3 pairs of burst region patterns (M=3), the advantages are extremely great. few.

In addition, the above-mentioned experimental example adheres to the condition of ensuring the linearity of the position error signal, and in the actual device, the condition that the read head width Wr (magnetic read width Wr) cannot be directly reproduced adjacent data tracks is added.

That is, when the data track width is W and the track pitch is Tp, the condition of Wr<2Tp-W is required. That is, as shown in FIG. 85, it is a condition that the magnetic read width Wr does not span two adjacent data tracks.

In particular, the magnetic recording device of the present invention is installed and used in a computer, and can be utilized in the information recording device industry.

Claims (9)

1. A magnetic recording and reproducing apparatus is provided with: a magnetic recording medium comprising a data information recording section and a tracking servo information section; when detecting the servo information of the servo information section, the data information is recorded in the information section The magnetic head for recording and reproducing the above-mentioned data information, wherein, The data information recording unit has data tracks with a data track pitch Tp, The servo information portion is composed of a magnetic recording layer formed in a predetermined concave-convex pattern, The servo information unit includes a burst unit for recording a tracking burst signal, The burst portion includes a first burst area, a second burst area, a third burst area, and a fourth burst area composed of a magnetic recording layer on which burst signals are recorded, a plurality of protrusions, The first burst area and the second burst area are arranged in pairs, and the magnetic recording layer of the convex portion is formed on the center line at a position staggered by a distance 2Tp of 2 track pitches from each other in the track width direction, The third burst area and the fourth burst area are arranged in a pair, and the position offset from each other by a distance 2Tp of 2 track pitches in the track width direction is the center line to form the magnetic recording layer of the convex portion. The centerlines of the burst region and the fourth burst region are arranged at positions staggered by a distance 1Tp of 1 track pitch from the centerlines of the first burst region and the second burst region, so as to form the protrusions. magnetic recording layer, The magnetic recording layer of the convex portion has a trapezoidal shape in the track width direction and the track circumferential direction, respectively, On the trapezoidal shape in the track width direction, the upper edge corresponding to the surface of the convex magnetic recording layer is W1, the lower edge corresponding to the bottom surface of the convex magnetic recording layer is W2, and the lower edge of the convex magnetic recording layer is When the height from W2 to the top, namely W1, is h, Satisfy the condition of tan85°≥2h/(W2-W1)≥tan50°, Let the data track width be W, and the magnetic head readout width be Wr, Satisfy the condition of Wr<2Tp-W, Where W1>Tp, and satisfy the condition of 1.25W2>Wr≥0.5W2. 2. A magnetic recording and reproducing apparatus is provided with: a magnetic recording medium comprising a data information recording section and a tracking servo information section; while detecting the servo information of the servo information section, the data information is recorded in the said servo information section. The magnetic head for recording and reproducing the above-mentioned data information, wherein, The data information recording section has data tracks with a data track pitch Tp, The servo information portion is composed of a magnetic recording layer formed in a predetermined concave-convex pattern, The servo information unit includes a burst unit for recording a burst signal for tracking, The burst portion includes a first burst area, a second burst area, a third burst area, and a fourth burst area composed of a magnetic recording layer on which burst signals are recorded, a plurality of protrusions, The first burst area and the second burst area are arranged in pairs, and are separated from each other in the track width direction. track pitch distance

The staggered position is the central line to form the magnetic recording layer of the convex portion, The third burst area and the fourth burst area are arranged in pairs, and are separated from each other in the track width direction.

track pitch distance

The staggered position is the central line forming the magnetic recording layer of the convex part, and at the same time, the center lines of the third burst area and the fourth burst area are respectively arranged in the distance from the first burst area and the second burst area. center line staggered

track pitch distance

position to form a convex portion of the magnetic recording layer, The magnetic recording layer of the convex portion has a trapezoidal shape in the track width direction and the track circumferential direction, respectively, On the trapezoidal shape in the track width direction, the upper edge corresponding to the surface of the convex magnetic recording layer is W1, the lower edge corresponding to the bottom surface of the convex magnetic recording layer is W2, and the lower edge of the convex magnetic recording layer is When the height from W2 to W1 is h, Satisfy the condition of tan85°≥2h/(W2-W1)≥tan50°, Let the data track width be W, and the magnetic head readout width be Wr, Satisfy the condition of Wr<2Tp-W, Wherein Tp>W2, and satisfy the condition of 1.5W2≥Wr≥0.5W1. 3. A magnetic recording and reproducing device is provided with: a magnetic recording medium comprising a data information recording section and a tracking servo information section; while detecting the servo information of the servo information section, the data information is recorded in the information section. The magnetic head for recording and reproducing the above-mentioned data information, wherein, The data information recording section has data tracks with a data track pitch Tp, The servo information portion is composed of a magnetic recording layer formed in a predetermined concave-convex pattern, The servo information unit includes a burst unit for recording a burst signal for tracking, The burst portion includes a first burst area, a second burst area, a third burst area, a fourth burst area, a fifth burst area, and a magnetic recording layer in which burst signals are recorded. Development area and the sixth outbreak area, The first burst area and the second burst area are arranged in pairs, and the magnetic recording layer of the convex portion is formed on the center line at a position staggered by a distance 1Tp of 1 track pitch from each other in the track width direction, The third burst area and the fourth burst area are arranged in a pair, and the position offset from each other by a distance 1Tp of 1 track pitch in the track width direction is the center line to form a magnetic recording layer of a convex portion. The central lines of the first burst area and the fourth burst area are configured to be staggered from the center lines of the first burst area and the second burst area track pitch distance

position to form a convex portion of the magnetic recording layer, The fifth burst area and the sixth burst area are arranged in a pair, and the position offset from each other by a distance 1Tp of 1 track pitch in the track width direction is the center line to form a magnetic recording layer of a convex portion. The centerlines of the burst area and the sixth burst area are respectively arranged to be staggered from the center lines of the first burst area and the second burst area

track pitch distance

position to form a convex portion of the magnetic recording layer, The magnetic recording layer of the convex portion has a trapezoidal shape in the track width direction and the track circumferential direction, respectively, On the trapezoidal shape in the track width direction, the upper edge corresponding to the surface of the convex magnetic recording layer is W1, the lower edge corresponding to the bottom surface of the convex magnetic recording layer is W2, and the lower edge of the convex magnetic recording layer is When the height from W2 to W1 is h, Satisfy the condition of tan85°≥2h/(W2-W1)≥tan50°, Let the data track width be W, and the magnetic head readout width be Wr, Satisfy the condition of Wr<2Tp-W, Where Tp>W2, and satisfy the conditions of 2W2>Wr≥0.5W2 and 0.5W2<W1. 4. A magnetic recording and reproducing apparatus is provided with: a magnetic recording medium comprising a data information recording section and a tracking servo information section; while detecting the servo information of the servo information section, the data information is recorded in the said servo information section. The magnetic head for recording and reproducing the above-mentioned data information, wherein, The data information recording section has data tracks with a data track pitch Tp, The servo information portion is composed of a magnetic recording layer formed in a predetermined concave-convex pattern, The servo information unit includes a burst unit for recording a burst signal for tracking, The burst portion includes a first burst area, a second burst area, a third burst area, a fourth burst area, a fifth burst area, and a magnetic recording layer in which burst signals are recorded. Development area and the sixth outbreak area, The first burst area and the second burst area are arranged in pairs, and the magnetic recording layer of the convex portion is formed on the center line at a position staggered by a distance 1Tp of 1 track pitch from each other in the track width direction, The third burst area and the fourth burst area are arranged in a pair, and the position offset from each other by a distance 1Tp of 1 track pitch in the track width direction is the center line to form a magnetic recording layer of a convex portion. The center lines of the burst area and the fourth burst area are respectively arranged to be staggered from the center lines of the first burst area and the second burst area track pitch distance

position to form a convex portion of the magnetic recording layer, The fifth burst area and the sixth burst area are arranged in a pair, and the position offset from each other by a distance 1Tp of 1 track pitch in the track width direction is the center line to form a magnetic recording layer of a convex portion. The centerlines of the burst area and the sixth burst area are respectively arranged to be staggered from the center lines of the first burst area and the second burst area

track pitch distance position to form a convex portion of the magnetic recording layer, The magnetic recording layer of the convex portion has a trapezoidal shape in the track width direction and the track circumferential direction, respectively, On the trapezoidal shape in the track width direction, the upper edge corresponding to the surface of the convex magnetic recording layer is W1, the lower edge corresponding to the bottom surface of the convex magnetic recording layer is W2, and the lower edge of the convex magnetic recording layer is When the height from W2 to W1 is h, Satisfy the condition of tan85°≥2h/(W2-W1)≥tan50°, Let the data track width be W, and the magnetic head readout width be Wr, Satisfy the condition of Wr<2Tp-W, Wherein Tp=W2, and satisfy the conditions of 2W2-W1≥Wr≥0.444W2 and 0.444W2<W1. 5. A magnetic recording and reproducing device is provided with: a magnetic recording medium comprising a data information recording section and a tracking servo information section; while detecting the servo information of the servo information section, the data information is recorded in the servo information section. The magnetic head for recording and reproducing the above-mentioned data information, wherein, The data information recording section has data tracks with a data track pitch Tp, The servo information portion is composed of a magnetic recording layer formed in a predetermined concave-convex pattern, The servo information unit includes a burst unit for recording a burst signal for tracking, The burst portion includes a first burst area, a second burst area, a third burst area, a fourth burst area, a fifth burst area, and a magnetic recording layer in which burst signals are recorded. Development area and the sixth outbreak area, The first burst area and the second burst area are arranged in pairs, and the magnetic recording layer of the convex portion is formed on the center line at a position staggered by a distance 1Tp of 1 track pitch from each other in the track width direction, The third burst area and the fourth burst area are arranged in a pair, and the position offset from each other by a distance 1Tp of 1 track pitch in the track width direction is the center line to form a magnetic recording layer of a convex portion. The center lines of the burst area and the fourth burst area are respectively arranged to be staggered from the center lines of the first burst area and the second burst area

track pitch distance

position to form a convex portion of the magnetic recording layer, The fifth burst area and the sixth burst area are arranged in a pair, and the position offset from each other by a distance 1Tp of 1 track pitch in the track width direction is the center line to form a magnetic recording layer of a convex portion. The centerlines of the burst area and the sixth burst area are respectively arranged to be staggered from the center lines of the first burst area and the second burst area

track pitch distance

position to form a convex portion of the magnetic recording layer, The magnetic recording layer of the convex portion has a trapezoidal shape in the track width direction and the track circumferential direction, respectively, On the trapezoidal shape in the track width direction, the upper edge corresponding to the surface of the convex magnetic recording layer is W1, the lower edge corresponding to the bottom surface of the convex magnetic recording layer is W2, and the lower edge of the convex magnetic recording layer is When the height from W2 to W1 is h, Satisfy the condition of tan85°≥2h/(W2-W1)≥tan50°, Let the data track width be W, and the magnetic head readout width be Wr, Satisfy the condition of Wr<2Tp-W, Where Tp=W1, and the condition of 1.5W1≥Wr≥0.444W1 is satisfied. 6. A magnetic recording and reproducing apparatus is provided with: a magnetic recording medium comprising a data information recording section and a tracking servo information section; while detecting the servo information of the servo information section, the data information is recorded in the said servo information section. The magnetic head for recording and reproducing the above-mentioned data information, wherein, The data information recording section has data tracks with a data track pitch Tp, The servo information portion is composed of a magnetic recording layer formed in a predetermined concave-convex pattern, The servo information unit includes a burst unit for recording a burst signal for tracking, The burst portion includes a first burst area, a second burst area, a third burst area, a fourth burst area, a fifth burst area, and a magnetic recording layer in which burst signals are recorded. Development area and the sixth outbreak area, The first burst area and the second burst area are arranged in pairs, and the magnetic recording layer of the convex portion is formed on the center line at a position staggered by a distance 1Tp of 1 track pitch from each other in the track width direction, The third burst area and the fourth burst area are arranged in a pair, and the position offset from each other by a distance 1Tp of 1 track pitch in the track width direction is the center line to form a magnetic recording layer of a convex portion. The center lines of the burst area and the fourth burst area are respectively arranged to be staggered from the center lines of the first burst area and the second burst area

track pitch distance

position to form a convex portion of the magnetic recording layer, The fifth burst area and the sixth burst area are arranged in a pair, and the position offset from each other by a distance 1Tp of 1 track pitch in the track width direction is the center line to form a magnetic recording layer of a convex portion. The centerlines of the burst area and the sixth burst area are respectively arranged to be staggered from the center lines of the first burst area and the second burst area

track pitch distance

position to form a convex portion of the magnetic recording layer, The magnetic recording layer of the convex portion has a trapezoidal shape in the track width direction and the track circumferential direction, respectively, On the trapezoidal shape in the track width direction, the upper edge corresponding to the surface of the convex magnetic recording layer is W1, the lower edge corresponding to the bottom surface of the convex magnetic recording layer is W2, and the lower edge of the convex magnetic recording layer is When the height from W2 to W1 is h, Satisfy the condition of tan85°≥2h/(W2-W1)≥tan50°, Let the data track width be W, and the magnetic head readout width be Wr, Satisfy the condition of Wr<2Tp-W, Wherein Tp<W1, and satisfy the condition of 1.5W1≥Wr≥0.333W2. 7. A magnetic recording and reproducing apparatus is provided with: a magnetic recording medium comprising a data information recording section and a tracking servo information section; while detecting the servo information of the servo information section, the data information is recorded in the said servo information section. The magnetic head for recording and reproducing the above-mentioned data information, wherein, The data information recording section has data tracks with a data track pitch Tp, The servo information portion is composed of a magnetic recording layer formed in a predetermined concave-convex pattern, The servo information unit includes a burst unit for recording a burst signal for tracking, The burst portion includes a first burst area, a second burst area, a third burst area, a fourth burst area, a fifth burst area, and a magnetic recording layer in which burst signals are recorded. Development area and the sixth outbreak area, The first burst area and the second burst area are arranged in pairs, and are separated from each other in the track width direction.

track pitch distance The staggered position is the central line to form the magnetic recording layer of the convex portion, The third burst area and the fourth burst area are arranged in pairs, and are separated from each other in the track width direction.

track pitch distance

The staggered position is the central line forming the magnetic recording layer of the convex part, and at the same time, the center lines of the third burst area and the fourth burst area are respectively arranged in the distance from the first burst area and the second burst area. center line staggered

track pitch distance

position to form a convex portion of the magnetic recording layer, The fifth burst area and the sixth burst area are configured in pairs, and are separated from each other in the track width direction.

track pitch distance

The staggered position is the central line forming the magnetic recording layer of the convex part, and at the same time, the central lines of the fifth burst area and the sixth burst area are respectively arranged in the distance from the first burst area and the second burst area. The center line is staggered respectively track pitch distance

position to form a convex portion of the magnetic recording layer, The magnetic recording layer of the convex portion has a trapezoidal shape in the track width direction and the track circumferential direction, respectively, On the trapezoidal shape in the track width direction, the upper edge corresponding to the surface of the convex magnetic recording layer is W1, the lower edge corresponding to the bottom surface of the convex magnetic recording layer is W2, and the lower edge of the convex magnetic recording layer is When the height from W2 to W1 is h, Satisfy the condition of tan85°≥2h/(W2-W1)≥tan50°, Let the data track width be W, and the magnetic head readout width be Wr, Satisfy the condition of Wr<2Tp-W, Wherein Tp>W2, and satisfy the condition of 1.5W2≥Wr≥0.5W1. 8. A magnetic recording and reproducing apparatus is provided with: a magnetic recording medium comprising a data information recording section and a tracking servo information section; while detecting the servo information of the servo information section, the data information is recorded in the said servo information section. The magnetic head for recording and reproducing the above-mentioned data information, wherein, The data information recording section has data tracks with a data track pitch Tp, The servo information portion is composed of a magnetic recording layer formed in a predetermined concave-convex pattern, The servo information unit includes a burst unit for recording a burst signal for tracking, The burst portion includes a first burst area, a second burst area, a third burst area, a fourth burst area, a fifth burst area, and a magnetic recording layer in which burst signals are recorded. Development area and the sixth outbreak area, The first burst area and the second burst area are arranged in pairs, and are separated from each other in the track width direction.

track pitch distance

The staggered position is the central line to form the magnetic recording layer of the convex portion, The third burst area and the fourth burst area are arranged in pairs, and are separated from each other in the track width direction.

track pitch distance

The staggered position is the central line forming the magnetic recording layer of the convex part, and at the same time, the center lines of the third burst area and the fourth burst area are respectively arranged in the distance from the first burst area and the second burst area. center line staggered

track pitch distance

position to form a convex portion of the magnetic recording layer, The fifth burst area and the sixth burst area are configured in pairs, and are separated from each other in the track width direction.

track pitch distance

The staggered position is the central line forming the magnetic recording layer of the convex part, and at the same time, the central lines of the fifth burst area and the sixth burst area are respectively arranged in the distance from the first burst area and the second burst area. The centerlines are respectively staggered by a distance of 1Tp per track pitch to form a convex magnetic recording layer, The magnetic recording layer of the convex portion has a trapezoidal shape in the track width direction and the track circumferential direction, respectively, On the trapezoidal shape in the track width direction, the upper edge corresponding to the surface of the convex magnetic recording layer is W1, the lower edge corresponding to the bottom surface of the convex magnetic recording layer is W2, and the lower edge of the convex magnetic recording layer is When the height from W2 to W1 is h, Satisfy the condition of tan85°≥2h/(W2-W1)≥tan50°, Let the data track width be W, and the magnetic head readout width be Wr, Satisfy the condition of Wr<2Tp-W, Where W1>Tp, and satisfy the conditions of 1.5W2>Wr≥0.333W2 and 0.333W2<W1. 9. A magnetic recording and reproducing apparatus is provided with: a magnetic recording medium comprising a data information recording section and a tracking servo information section; while detecting the servo information of the servo information section, the data information is recorded in the said servo information section. The magnetic head for recording and reproducing the above-mentioned data information, wherein, The data information recording section has data tracks with a data track pitch Tp, The servo information portion is composed of a magnetic recording layer formed in a predetermined concave-convex pattern, The servo information unit includes a burst unit for recording a burst signal for tracking, The burst portion includes a first burst area, a second burst area, a third burst area, a fourth burst area, a fifth burst area, and a magnetic recording layer in which burst signals are recorded. Development area and the sixth outbreak area, The first burst area and the second burst area are arranged in pairs, and the magnetic recording layer of the convex portion is formed on the center line at a position staggered by a distance 3Tp of 3 track pitches in the track width direction, The third burst area and the fourth burst area are arranged in a pair, and the positions offset from each other by a distance 3Tp of 3 track pitches in the track width direction are used as the center line to form the magnetic recording layer of the convex portion. The centerlines of the burst region and the fourth burst region are respectively arranged at positions staggered by a distance 1Tp of 1 track pitch from the centerlines of the first burst region and the second burst region, so as to form the protrusions. magnetic recording layer, The fifth burst area and the sixth burst area are arranged in a pair, and the position staggered by a distance 3Tp of 3 track pitches in the track width direction is the center line to form a magnetic recording layer of a convex portion. The centerlines of the burst region and the sixth burst region are respectively arranged at positions staggered by a distance 2Tp of 2 track pitches from the centerlines of the first burst region and the second burst region, so as to form convex portions the magnetic recording layer, The magnetic recording layer of the convex portion has a trapezoidal shape in the track width direction and the track circumferential direction, respectively, On the trapezoidal shape in the track width direction, the upper edge corresponding to the surface of the convex magnetic recording layer is W1, the lower edge corresponding to the bottom surface of the convex magnetic recording layer is W2, and the lower edge of the convex magnetic recording layer is When the height from W2 to W1 is h, Satisfy the condition of tan85°≥2h/(W2-W1)≥tan50°, Let the data track width be W, and the magnetic head readout width be Wr, Satisfy the condition of Wr<2Tp-W, Where W1>Tp, and satisfy the condition of 1.5W2>Wr≥0.444W2.

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