WO1999045534A1 - Magnetic disc device - Google Patents

Magnetic disc device Download PDF

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Publication number
WO1999045534A1
WO1999045534A1 PCT/JP1998/000884 JP9800884W WO9945534A1 WO 1999045534 A1 WO1999045534 A1 WO 1999045534A1 JP 9800884 W JP9800884 W JP 9800884W WO 9945534 A1 WO9945534 A1 WO 9945534A1
Authority
WO
WIPO (PCT)
Prior art keywords
magnetic disk
recording
track
width
disk drive
Prior art date
Application number
PCT/JP1998/000884
Other languages
French (fr)
Japanese (ja)
Inventor
Takehiko Hamaguchi
Atsushi Nakamura
Yasutaka Nishida
Hisashi Takano
Yohji Maruyama
Hiroshi Ide
Hideki Sawaguchi
Futoshi Tomiyama
Original Assignee
Hitachi, Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hitachi, Ltd. filed Critical Hitachi, Ltd.
Priority to JP2000535001A priority Critical patent/JP3689638B2/en
Priority to PCT/JP1998/000884 priority patent/WO1999045534A1/en
Priority to KR10-2000-7009157A priority patent/KR100479013B1/en
Publication of WO1999045534A1 publication Critical patent/WO1999045534A1/en
Priority to US11/404,780 priority patent/US7443625B2/en

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Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/02—Recording, reproducing, or erasing methods; Read, write or erase circuits therefor
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10—Digital recording or reproducing
    • G11B20/12—Formatting, e.g. arrangement of data block or words on the record carriers
    • G11B20/1217—Formatting, e.g. arrangement of data block or words on the record carriers on discs
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/012—Recording on, or reproducing or erasing from, magnetic disks
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
    • G11B5/54—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head into or out of its operative position or across tracks
    • G11B5/55—Track change, selection or acquisition by displacement of the head
    • G11B5/5504—Track change, selection or acquisition by displacement of the head across tape tracks
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10—Digital recording or reproducing
    • G11B20/12—Formatting, e.g. arrangement of data block or words on the record carriers
    • G11B20/1217—Formatting, e.g. arrangement of data block or words on the record carriers on discs
    • G11B2020/1218—Formatting, e.g. arrangement of data block or words on the record carriers on discs wherein the formatting concerns a specific area of the disc
    • G11B2020/1232—Formatting, e.g. arrangement of data block or words on the record carriers on discs wherein the formatting concerns a specific area of the disc sector, i.e. the minimal addressable physical data unit
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10—Digital recording or reproducing
    • G11B20/12—Formatting, e.g. arrangement of data block or words on the record carriers
    • G11B20/1217—Formatting, e.g. arrangement of data block or words on the record carriers on discs
    • G11B2020/1218—Formatting, e.g. arrangement of data block or words on the record carriers on discs wherein the formatting concerns a specific area of the disc
    • G11B2020/1238—Formatting, e.g. arrangement of data block or words on the record carriers on discs wherein the formatting concerns a specific area of the disc track, i.e. the entire a spirally or concentrically arranged path on which the recording marks are located
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B20/00—Signal processing not specific to the method of recording or reproducing; Circuits therefor
    • G11B20/10—Digital recording or reproducing
    • G11B20/12—Formatting, e.g. arrangement of data block or words on the record carriers
    • G11B2020/1264—Formatting, e.g. arrangement of data block or words on the record carriers wherein the formatting concerns a specific kind of data
    • G11B2020/1265—Control data, system data or management information, i.e. data used to access or process user data
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B2220/00—Record carriers by type
    • G11B2220/20—Disc-shaped record carriers
    • G11B2220/21—Disc-shaped record carriers characterised in that the disc is of read-only, rewritable, or recordable type
    • G11B2220/215—Recordable discs
    • G11B2220/216—Rewritable discs

Definitions

  • the present invention relates to a magnetic disk drive for recording and reproducing magnetic information on a magnetic disk using a composite head.
  • the magnetic disk drive moves the head in the radial direction with respect to the rotating disk, accurately positions the target data track, and magnetically records and reproduces information.
  • FIG. 3 is a cross-sectional view illustrating a schematic configuration of a typical magnetic disk drive.
  • eight heads 11 are supported by a single rotary actuator 13 driven by a voice coil motor 14.
  • Each of the eight heads 11 performs recording and reproduction on both sides of the four discs 12.
  • FIG. 4 is a plan view showing a schematic configuration of the present apparatus.
  • the rotary actuator 13 is driven by a voice coil motor to move the head 11 in the radial direction of the rotating disk 12.
  • Fig. 5 shows a schematic diagram of a part of this device as viewed from above. Before shipment from the factory, special magnetic information indicating the positional information of the head is written on the magnetic disk 12. Based on this position information, the CPU (central control unit) determines the power to be supplied to the voice coil motor, and performs accurate positioning of the head 11 on the target track 15 via the rotary actuator 13. Do. In Fig. 5, track 15 is indicated by a solid line. Tracks are formed by magnetic information and are not actually directly recognizable optically.
  • FIG. 6 shows a schematic view of the head portion of the magnetic disk drive seen through from above.
  • the head 11 has a structure called a composite head or a recording / reproducing separation head in which a magnetoresistive read element 61 and an inductive write element 62 are stacked on the same slider. ing.
  • the reproducing element 61 a technique using an MR element utilizing the magnetoresistance effect of an iron-nickel alloy is widely known. Practical application of GMR elements using iron-nickel alloys with nonmagnetic materials is also being considered.
  • the MR element is an effective technology for increasing the recording density of a magnetic disk drive because it has the feature of being excellent in the read sensitivity of short-wavelength recorded information.
  • the recording element 62 Since a magnetoresistive element represented by the MR element cannot perform a recording operation, an inductive element formed by etching a thin film to form minute magnetic poles and coils is used as the recording element 62.
  • the operating principle of the inductive element is the same as that of a tape recorder that has been widely used in the past. Most of the magnetic disk devices announced in recent years adopt this composite head.
  • the read element 61 and the write element 62 are indicated by rectangular symbols. This is to visually explain the width and position of the element, and is different from the actual optical shape of the element. This is the same in the following drawings for explaining the widths and positions of the elements.
  • a major feature of magnetic disk drives is that they can arbitrarily rewrite stored information. Most components of the old magnetization information are masked by overwriting the new magnetization information on the data track on which the old magnetization information has been written.
  • This recording method is called the direct overwrite recording method, and since it does not require an erasing step and can achieve high performance, it is used in all magnetic disk devices.
  • the width of the recording element 62 is made smaller than the track pitch as shown in FIG. 6 so that adjacent data tracks are not erased. Ensuring reliability. This is because the head magnetic field at the time of recording spreads in the track width direction, and regions where old magnetization information is erased are formed on both sides of the recording track.
  • the recording width including the erased areas on both sides is called the erase width.
  • the width of the reproducing element 61 is determined in consideration of the positioning error of the head between recording and reproduction, as disclosed in Japanese Patent Laid-Open No. 59-169905. It is desirable to make the width smaller than the recording width as long as the signal SZN can be secured. By setting the recording element width and the reproducing element width appropriately for the track pitch, it is possible to avoid the risk of erasing adjacent tracks during recording and losing data. Furthermore, it is possible to realize a magnetic disk device that has a low frequency of retries at the time of reproduction that degrades performance performance, and that obtains an excellent bit error rate with a sufficient signal S / N.
  • the magnetoresistive effect element represented by this MR element has the characteristic of excellent reproduction sensitivity, and is effective for increasing the recording density in the rotation direction of the magnetic disk and increasing the track density in the radial direction of the magnetic disk.
  • the inductive element which is a recording element, cannot pass through a magnetic flux necessary for reversing the magnetization of the magnetic layer of the magnetic disk, so that its cross-sectional area cannot be reduced. For this reason, when the track width is reduced, the thickness of the magnetic pole tends to increase.
  • the magnetic pole of an inductive element having a track width of 1.5 ⁇ m in the width direction requires a thick structure of 3 / ⁇ ⁇ or more. For this reason, maintaining a sufficiently small tolerance in the track width direction is a major issue.
  • the aspect ratio defined by the height / width of the magnetic pole cross-sectional shape becomes extremely large from 1, the structural magnetic resistance increases and the magnetic anisotropy of the magnetic pole decreases.
  • the above-mentioned problems are solved by using a technology in which the recording track width formed by the recording elements is made larger than the track pitch, and recording is performed sequentially while shifting one track at a time in the radial direction of the magnetic disk. can do.
  • the problem can be solved by using a technique in which the erase track width formed by the recording elements is set to an integral multiple of the track pitch and recording is performed sequentially while shifting one track in the radial direction of the magnetic disk. Can be.
  • Another solution is to use a configuration in which the geometric width of the recording element is at least twice the geometric width of the reproducing element, and using the technology of recording sequentially while shifting one track in the radial direction of the magnetic disk.
  • the above problems can be solved and the performance performance of a magnetic disk device using the present technique can be improved.
  • the performance performance at the initial use can be maintained for a long time.
  • FIG. 1 is a diagram for explaining the relationship between the width of a recording / reproducing element and a track pitch in a first embodiment of the magnetic disk drive of the present invention.
  • FIG. 2 is a diagram for explaining the relationship between the width of the recording and reproducing elements and the track pitch in the embodiment of the conventional magnetic disk drive.
  • FIG. 3 is a cross-sectional view illustrating an example of a schematic configuration of a magnetic disk drive.
  • FIG. 4 is a plan view illustrating an example of a schematic configuration of a magnetic disk drive.
  • FIG. 5 is a schematic view of a part of the magnetic disk drive as viewed from above.
  • FIG. 6 is a schematic view of the head portion of the magnetic disk drive as seen through from above.
  • FIG. 7 is a diagram for explaining the relationship between the width of the recording / reproducing element and the track pitch in the second embodiment of the magnetic disk drive of the present invention.
  • FIG. 8 is a diagram illustrating the relationship between the overwrite characteristics and the print element width.
  • FIG. 9 is a diagram for explaining the geometrical relationship between the reproducing element width and the recording element width in the third embodiment of the magnetic disk drive of the present invention.
  • FIG. 10 is a diagram for explaining the relationship between the effective recording track width, the effective erase track width, and the recording element width.
  • FIG. 11 is a diagram for explaining the relationship between the recording and erasing track width and the track pitch in the fourth embodiment of the magnetic disk drive of the present invention.
  • FIG. 12 is a diagram for explaining a state in which magnetization information is added and a step of updating the contents of the slip destination data table when recording new data in the magnetic disk device of the present invention.
  • FIG. 13 is a diagram for explaining a state in which magnetization information is added and a step of updating the contents of the slip destination data table when overwriting data is recorded on the magnetic disk device of the present invention.
  • FIG. 14 is a diagram illustrating a defragmentation processing step of the slip destination data table of the magnetic disk device of the present invention.
  • FIG. 15 is a diagram for explaining that, in one embodiment of the magnetic disk drive of the present invention, the zone area on the outer peripheral side of the magnetic disk is set so that the track pitch is wider than the recording element width. .
  • FIG. 16 is a view for explaining the relationship between the width of the recording / reproducing element and the track pitch in an area where the track pitch is widened in one embodiment of the magnetic disk drive of the present invention.
  • FIG. 17 is a diagram for explaining that in one embodiment of the magnetic disk drive of the present invention, a partial area of each zone of the magnetic disk is set to an area where the track pitch is wider than the recording element width. is there.
  • Embodiment 1 The basic configuration of the magnetic disk drive of the present invention is almost the same as the embodiment described in the section of the prior art with reference to FIGS. 3, 4, and 5.
  • FIG. 1 The relationship between the width of the recording / reproducing element and the track pitch is shown as an example of the present invention. Embodiments and features of the present invention will be described by comparing FIG. 1 shown in FIG. 1 with FIG. 2 showing an example of the related art.
  • the head records and reproduces magnetization information while moving from left to right in the drawing relative to the disk.
  • the recording element 62 or the pattern on the left side of the recording element 64 corresponds to the newly recorded magnetization information, and is represented as the track 71 recorded this time.
  • the pattern on the right side of 64 is the magnetization information to be overwritten and erased, and is shown as a discardable track 73 in both figures. Unaffected truck
  • the previous magnetization information is maintained as it is.
  • the track pitch is reduced to about half that of the conventional technique shown in FIG. 2, and about twice the data can be stored per unit area.
  • the reproducing element 62 of the present invention is made narrower than the track pitch so as not to reproduce the magnetization information of the adjacent track. For this reason, the reproducing element 62 of the present invention is about half as wide as the reproducing element 61 of the prior art.
  • the recording element 64 of the present invention wider than the track pitch, the width can be made equivalent to that of the recording element 62 of the prior art. As a result, the recording element 64 was able to generate a recording magnetic field having a sufficient intensity, and the magnetic disk device of the present invention was able to achieve good overwrite characteristics and a high signal SN ratio.
  • an operation of shaping the magnetization information of the adjacent track to a width equal to or less than the track pitch together with the recording operation can be performed. That is, during recording, following control is performed at the head position as shown in FIG.
  • the data track 72 having a width sufficient for reproducing the magnetization information by the element 62 can be formed. Also, by performing recording while maintaining this positional relationship, it is possible to avoid interference with the adjacent track 74 on the opposite side.
  • the width of the reproducing element 62 is narrower than the track pitch in the present invention shown in FIG. 1, if the technology for separating magnetization information from adjacent tracks by signal processing in the future progresses, the width of the reproducing element 62 will be smaller than the track pitch. Can also be wide. Furthermore, by using a simple coding method for adjacent tracks, it is possible to positively reproduce two data tracks at the same time and improve the transfer speed.
  • the composite head of this magnetic disk drive has a recording element 66 equivalent to about three times the track pitch.
  • the pattern to be overwritten and erased with the recording of new magnetization information has a width of two tracks as shown as a discardable track 73.
  • the recording element 66 having a width approximately three times the track pitch as in this embodiment, a magnetic disk device with a narrower track pitch can be realized.
  • the ratio between the recording element width and the track pitch can be increased to 4, 5, and 6 to realize a magnetic disk device with a higher track density.
  • any of the embodiments described above by sequentially performing recording in one radial direction of the disk, data tracks corresponding to narrow track pitches can be formed correctly. According to the invention. It is possible to provide an inexpensive and large-capacity magnetic disk device that is particularly suitable for storing images that require a large number of serial data transfer requests. By providing the magnetic disk device of the present invention with a dummy track corresponding to the unit of image transfer, performance performance can be remarkably improved. For example, transfer By increasing the block capacity, which is a unit, to a capacity of about 10 seconds for an image, it is possible to reduce the formatting efficiency due to dummy tracks, and to achieve magnetic access with the same random access performance as conventional magnetic disk drives. A disk device can be realized. Furthermore, by setting the transfer unit to be a variable block and making the size of the block correspond to the joint of the recorded images, it is possible to reduce the formatting efficiency due to the dummy track so as to be almost negligible.
  • Japanese Patent Application Laid-Open No. 1-94557 discloses a technique in which a recording element wider than the track pitch is used for forming a servo pattern in order to form a wide servo pattern.
  • Japanese Patent Application Laid-Open No. Hei 5-292840 discloses a technique for erasing the magnetic information of a magnetic disk while shifting it at a narrow pitch as a method of using the recording element while shifting it.
  • a technique for making the width of the element corresponding to the lower mode out of a plurality of elements wider than the track pitch of the upper mode for a two-mode floppy device is a special feature. It is disclosed in Japanese Unexamined Patent Publication No. Hei. None of the technologies shown here has a configuration in which the elements for recording data tracks are wider than the drag pitch, and does not use a method of overwriting adjacent data tracks. For this reason, the track pitch cannot be made smaller than the magnetic pole width of the recording element, which is fundamentally different from the technique of the present invention.
  • ⁇ Embodiment 2> In order to provide the magnetic disk drive of the present invention with performance performance suitable for more applications, a slip destination data table is provided, and replacement processing is performed for each sector or each track. It can be performed. Formation process of magnetization information on disk and data tape at slip destination Figure 12 shows the process of recording new data and Figure 13 shows the process of recording data.
  • FIG. 12 shows a magnetization state in which information has already been recorded up to track 101 and track 102 of the disk, and no effective data has been recorded after track 103.
  • the last bottler points to track 102.
  • the value of the slip (replacement) destination data table is initialized to 0, indicating that no track has been replaced.
  • recording new data following is performed according to the value of the last pointer (the last recorded track number) at the position where the recording element 64 extends over tracks 103 and 104.
  • While recording record the magnetization information.
  • the value of the last pointer is updated from 102 to 103.
  • FIG. 13 shows a magnetized state in which information has already been recorded from track 101 to track 103 of the disk, and no effective data has been recorded after track 104.
  • the last bottler points to track 103.
  • the magnetizing information is written while following the position of the recording element 64 over the tracks 104 and 105 according to the value of the last pointer. Record information.
  • the value of the last pointer is updated from 103 to 104, and the value of the track number 102 in the slip destination data table is updated from 0 to 2, and the track number 104 Write the value X of the referenced flag from 0 to 0.
  • the track number 104 When playing back the track 102 later, first, refer to the fact that the item of the track number 102 in the slip destination data table is 2 and play the track 104 obtained by adding 2 to 102. By doing so, new data that has been overwritten can be correctly retrieved.
  • step 1 the data of the track 103 is reproduced, and the reproduced information is recorded over the track 102 and the track 103.
  • the value of the slip destination data table updates the value of the track number 103 from 0 to 1 1.
  • step 2 the data of the track 104 is reproduced, and the reproduced information is recorded over the track 103 and the track 104.
  • the value of the slip destination data table is the reference source track. Update the value of the number 102 from 1 to 2.
  • step 3 The value of the last pointer is updated from 104 to 103, the value of the track number 104 of the data table of the slip destination is updated from to of the referenced flag to 0, and the defragmentation process ends. By this processing, the track 104 is restored as a usable track.
  • the defragmentation may be performed at a time interval set by the user in advance, or at an arbitrary time according to an instruction from the user.
  • the normal defragmentation process is performed at a time when there is no access request from the user for a certain period of time or longer.
  • the magnetic disk device of the present invention can respond to the access request from the user even during the process.
  • the disk area is changed as shown in FIG. 15 from zone 15 3 to zone 15 6 in the number of sectors in the track.
  • the following explanation uses a disk with four different zones as an example.
  • zone 1553 From the outer circumference of the disk, zone 1553 has 3600 sectors in one track, and zone 1554 has 324, in that order: zone155 has 288, zone 1556 is provided with 252 sectors.
  • a dummy track is provided at the zone boundary to avoid interference between adjacent data on the outer and inner tracks in the sector arrangement of the track.
  • the three zones 154 to 156 on the inner circumference side of the disk are narrow so that the width of the recording element 64 and the reproducing element 62 as shown in FIG. 1 is related to the track pitch.
  • the track pitch area is set to 152.
  • the wide track pitch area is set so that the relationship between the width of the recording element 68 and the reproducing element 67 and the track pitch as shown in FIG. 16 is obtained.
  • Set to 1 5 1 With this setting, data can be directly overwritten and replaced in zone 15 3 without performing replacement processing using the slip destination data table. Wear.
  • file allocation tables for operating systems to manage files, RAM disk files, and system swap files are data that can be replaced frequently.
  • the process of preferentially relocating specific data to the zone 153 can be realized by an application higher than the operation system.
  • the boundary between the wide track pitch area 15 1 and the narrow track pitch area 15 2 is not assigned by a special device such as a servo track writer before shipment from the factory.
  • This function is implemented by a program. By providing a function that can be changed arbitrarily by the user after the magnetic disk is shipped from the factory, it is possible to optimize the magnetic disk device that performs best in each usage environment.
  • a part of the area of the ⁇ zone can be allocated to an area having a wide track pitch.
  • the disk shown in FIG. 17 has four zones with different numbers of sectors in the tracks from zone 153 to zone 156 as in the disk shown in FIG.
  • the inner zone 156 all of the 252 sectors are allocated to the narrow track pitch area 162. From the three Zones 15 3 to 15 5 on the outer circumference of the disk, the area of the first 25 2 sectors is allocated to the narrow track pitch area 16 2, and the remaining sectors are wide track pitch. Allocated to area 16 1. With this setting, the number of sectors in one track of the narrow track pitch area 162 can be the same from the outer zone to the inner zone. For this reason, a slip destination data table is provided for each track, and hardware The load on the air controller can be reduced.
  • the effective recording track width can be defined by the half width of the magnetization pattern actually recorded on the disk.
  • the effective erase track width can be defined by the half-value width of the underlying track overwritten and erased by the magnetization pattern actually recorded on the disk.
  • a head having a recording element width of about 1.6; ⁇ was subjected to a trimming process to narrow the width to about 1.4 im, 1.1 ⁇ m, and 0.9 ⁇ m by an ion milling technique.
  • the graph of FIG. 10 shows the measured results of the effective recording track width and the effective erasing track width of this head, with the geometric width of the recording element of each head as the horizontal axis.
  • the effective erasure track width was wider than the effective recording track width, and the difference was almost constant at about 0.5 ⁇ m regardless of the geometric width of the recording element. This suggests that even if the geometric width of the recording element is reduced as much as possible, the effective erase track width remains at a certain width.
  • the magnetic disk drive of the present invention includes a head having a configuration in which the track pitch is set to about half of the effective erase track width.
  • the geometric width of the recording element had to be extremely narrow in order to make the effective erase: track width equal to the track pitch.
  • the magnetic disk device of the present invention was provided with the recording element 69 having a width capable of generating a sufficient recording magnetic field intensity, and was able to realize good overhead light characteristics and a high signal SN. Sequential recording described in the first embodiment, replacement processing using the slip destination data table described in the second embodiment, and multiple track pitches described in the third embodiment By applying the technology for setting the area of the disk, it is possible to provide a large-capacity magnetic disk device with even better performance performance.
  • the magnetic disk drive uses a direct overwrite method that overwrites and records new magnetization information on a data track on which old magnetization information is written.
  • the recording method is adopted. Since the old magnetization information can be masked without an erasing step, high performance performance can be realized. However, the component of the old magnetization information that remains slightly is difficult to separate because it is the same as the clock frequency of the new magnetization information, and is a direct factor that degrades the signal SN as a noise component.
  • the signal intensity ratio of the old magnetization information before and after overwriting the new magnetization information is called the overwrite characteristic. The smaller the overwrite characteristic, the smaller the noise component and the better the signal SN.
  • One target value of the overwrite characteristic required to obtain a sufficient signal SN is about 130 dB.
  • the magnetic disk drive of the present invention includes a head having a configuration in which the geometric width of the recording element 68 is at least twice the geometric width of the reproducing element 67.
  • the geometric width of the recording element is set to be about 1.2 to 1.5 times the geometric width of the reproducing element.
  • the effective reproduction track width is almost equal to the geometric width of the reproducing element, the geometric width of the recording element had to be extremely narrowed as the effective reproduction width became narrower than the track pitch.
  • the magnetic disk device of the present invention was provided with the recording element 68 having a width capable of generating a sufficient recording magnetic field intensity, and was able to achieve good overwrite characteristics and high signal SN.
  • This magnetic disk drive The sequential recording described in the first embodiment, the replacement process using the slip destination data table described in the second embodiment, and the technique of setting a plurality of track pitch areas described in the third embodiment are applied. By doing so, it is possible to provide a large-capacity magnetic disk device with even better performance performance. Industrial applicability
  • the present invention relates to a disk device using a composite head in which a recording element and a reproduction element are separated from each other by using a configuration in which a track pitch is smaller than a recording track width formed by the recording element. Since a decrease in the recording magnetic field intensity due to the narrowing of the width can be avoided, a large-capacity magnetic disk device with an increased track density can be realized.
  • slip destination data table it is possible to realize a magnetic disk device having random access performance capable of rewriting data at an arbitrary position.

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  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Digital Magnetic Recording (AREA)
  • Signal Processing For Digital Recording And Reproducing (AREA)

Abstract

A recording element needs to have a certain cross section in order to permit the magnetic flux for reversing the magnetization of the magnetic layer of a magnetic disc to pass. When the shape of the cross section of the pole has a large aspect ratio, the magnetic flux can not be passed through the pole effectively. This phenomenon determines the lower limit of the track width of the pole and makes impossible the increase of the track density. In order to solve this problem, the width of the recording element is wider than the track pitch to ensure a recording magnetic field intensity high enough to reverse the magnetization of the magnetic layer, and recording is performed by shifting a recording head having the recording element. A large capacity magnetic disc device whose recording element width is smaller than the track width is realized.

Description

明 細 書  Specification
磁気ディスク装置 技術分野 Magnetic disk drive Technical field
本発明は、 複合へッドを用いて磁気ディスクに磁気情報の記録おょぴ 再生を行う磁気ディスク装置に関する。 背景技術  The present invention relates to a magnetic disk drive for recording and reproducing magnetic information on a magnetic disk using a composite head. Background art
磁気ディスク装置は、 回転するディスクに対してへッドを半径方向 に移動させて、 目的とするデータ トラックに正確に位置決めを行い、 磁気的に情報の記録おょぴ再生を行なうものである。  The magnetic disk drive moves the head in the radial direction with respect to the rotating disk, accurately positions the target data track, and magnetically records and reproduces information.
代表的な磁気ディスク装置の概略的な構成を説明する断面図を図 3 に示す。 この例では 8.本のヘッド 1 1が、 ボイスコイルモータ 1 4に よって駆動される一つのロータリ型ァクチユエータ 1 3に支えられて いる。 8本のヘッド 1 1のそれぞれが、 4枚のディスク 1 2の各両面 に対して記録再生を行う。  FIG. 3 is a cross-sectional view illustrating a schematic configuration of a typical magnetic disk drive. In this example, eight heads 11 are supported by a single rotary actuator 13 driven by a voice coil motor 14. Each of the eight heads 11 performs recording and reproduction on both sides of the four discs 12.
本装置の概略的な構成を示す平面図を図 4に示す。 ロータリ型ァク チュエータ 1 3はボイスコイルモータによって駆動されて、 回転する ディスク 1 2の半径方向にへッド 1 1を移動させることができる。 また、 この装置の一部分を上面から見た模式図を図 5に示す。 磁気 ディスク 1 2には工場出荷前にへッドの位置情報を表す特殊な磁化 情報が書き込まれている。 この位置情報に基づいて C P U (中央制御 部） がボイスコイルモータに与える電力を決定し、 ロータリー型ァク チユエータ 1 3を介して目的のトラック 1 5に対するへッド 1 1の正 確な位置決めを行う。 なお図 5ではトラック 1 5を実線で明記したが、 トラックは磁気情報で形成されるものであり実際には光学的に直接認 識できるものではない。 FIG. 4 is a plan view showing a schematic configuration of the present apparatus. The rotary actuator 13 is driven by a voice coil motor to move the head 11 in the radial direction of the rotating disk 12. Fig. 5 shows a schematic diagram of a part of this device as viewed from above. Before shipment from the factory, special magnetic information indicating the positional information of the head is written on the magnetic disk 12. Based on this position information, the CPU (central control unit) determines the power to be supplied to the voice coil motor, and performs accurate positioning of the head 11 on the target track 15 via the rotary actuator 13. Do. In Fig. 5, track 15 is indicated by a solid line. Tracks are formed by magnetic information and are not actually directly recognizable optically.
次に、 磁気ディスク装置のへッド部分を上面から透視した模式図を図 6 に示す。 ヘッド 1 1には磁気抵抗効果型の再生素子 6 1とィンダクティ プ型の記録素子 6 2が同一のスライダー上に積層された複合型へッド もしくは録再分離型へッドと呼ばれる構造をしている。 再生素子 6 1に は、 鉄—ニッケル合金の磁気抵抗効果を利用した M R素子を用いる技術 が広く知られている。 また鉄一ニッケル合金を非磁性材料でサンドイツ チした G M R素子の実用化も検討されている。 M R素子は短波長の記録 情報の再生感度に優れる特徴を持つことから、磁気ディスク装置の記録 密度を高めるために有効な技術である。 この M R素子に代表される磁気 抵抗効果素子は記録動作を行うことができないために、 薄膜をエツチン グして微小な磁極やコィルを形成したインダクティブ素子を記録素子 6 2として用いる。 インダクティブ素子の動作原理は、 従来から広く用 いられているテープレコーダー等と同様である。 近年発表される磁気デ イスク装置のほとんどが， この複合型ヘッ ドを採用している. なお、 図 6では再生素子 6 1と記録素子 6 2を長方形の記号で示しているが、 便 宜的に素子の幅や位置を 覚的に説明するためであり、 実際の素子の光 学的な形状とは異なる。 これは素子の幅や位置を説明する以降の図面で も同様である。 Next, FIG. 6 shows a schematic view of the head portion of the magnetic disk drive seen through from above. The head 11 has a structure called a composite head or a recording / reproducing separation head in which a magnetoresistive read element 61 and an inductive write element 62 are stacked on the same slider. ing. As the reproducing element 61, a technique using an MR element utilizing the magnetoresistance effect of an iron-nickel alloy is widely known. Practical application of GMR elements using iron-nickel alloys with nonmagnetic materials is also being considered. The MR element is an effective technology for increasing the recording density of a magnetic disk drive because it has the feature of being excellent in the read sensitivity of short-wavelength recorded information. Since a magnetoresistive element represented by the MR element cannot perform a recording operation, an inductive element formed by etching a thin film to form minute magnetic poles and coils is used as the recording element 62. The operating principle of the inductive element is the same as that of a tape recorder that has been widely used in the past. Most of the magnetic disk devices announced in recent years adopt this composite head. In Fig. 6, the read element 61 and the write element 62 are indicated by rectangular symbols. This is to visually explain the width and position of the element, and is different from the actual optical shape of the element. This is the same in the following drawings for explaining the widths and positions of the elements.
磁気ディスク装置はいつたん記憶した情報を任意に書き換えできる ことが大きな特徴である。 古い磁化情報が書き込まれたデータトラック の上に新しい磁化情報が上書きされることにより、 古い磁化情報のほと んどの成分がマスクされる。 この記録方式は直接オーバーライ ト記録方 式と呼ばれ、消去工程を必要としないために高いパフォーマンス性能を 実現できることから、 全ての磁気ディスク装置で採用されている。 この直接オーバーライ ト記録方式を用いた磁気ディスク装置では、 隣 接するデータトラックを消去しないように図 6に示すように記録素子 6 2の幅をトラックピッチよりも狭くすることで、 磁気ディスク装置の 信頼性を確保する。 これは、 記録時のヘッド磁界がトラック幅方向への 広がりを持っためであり、 古い磁化情報が消去される領域が記録トラッ クの両側に形成されるからである。 この消去された両側の領域を含めた 記録幅は消去幅と呼ばれる。 さらに再生素子 6 1の幅は、 記録時と再生 時とのへッドの位置決め誤差分を考慮して、 特開昭 5 9— 1 6 8 9 0 5 号公報に開示されているように、 信号 S Z Nを確保できる範囲で記録幅 よりも狭い幅にすることが望ましい。 トラックピッチに対して適切な記 録素子幅と再生素子幅の設定を行うと、 記録時に隣接トラックを消去し てデータが失われる危険性を回避することができる。 さらに、 パフォー マンス性能を劣化させる再生時のリ トライの頻度が低く、 かつ十分な信 号 S / Nにより優れたビットエラーレートを得る磁気ディスク装置を 実現することができる。 A major feature of magnetic disk drives is that they can arbitrarily rewrite stored information. Most components of the old magnetization information are masked by overwriting the new magnetization information on the data track on which the old magnetization information has been written. This recording method is called the direct overwrite recording method, and since it does not require an erasing step and can achieve high performance, it is used in all magnetic disk devices. In a magnetic disk drive using this direct overwrite recording method, the width of the recording element 62 is made smaller than the track pitch as shown in FIG. 6 so that adjacent data tracks are not erased. Ensuring reliability. This is because the head magnetic field at the time of recording spreads in the track width direction, and regions where old magnetization information is erased are formed on both sides of the recording track. The recording width including the erased areas on both sides is called the erase width. Further, the width of the reproducing element 61 is determined in consideration of the positioning error of the head between recording and reproduction, as disclosed in Japanese Patent Laid-Open No. 59-169905. It is desirable to make the width smaller than the recording width as long as the signal SZN can be secured. By setting the recording element width and the reproducing element width appropriately for the track pitch, it is possible to avoid the risk of erasing adjacent tracks during recording and losing data. Furthermore, it is possible to realize a magnetic disk device that has a low frequency of retries at the time of reproduction that degrades performance performance, and that obtains an excellent bit error rate with a sufficient signal S / N.
この M R素子に代表される磁気抵抗効果素子は、 再生感度に優れる特 徴を持つことにより、 磁気ディスクの回転方向の記録密度を高めたり、 磁気ディスクの半径方向にあたるトラック密度を高めるために有効な 技術である。  The magnetoresistive effect element represented by this MR element has the characteristic of excellent reproduction sensitivity, and is effective for increasing the recording density in the rotation direction of the magnetic disk and increasing the track density in the radial direction of the magnetic disk. Technology.
しかし、 記録用の素子であるインダクティブ素子は、 磁気ディスクの 磁性層の磁化を反転させるために必要な磁束を通さなければならない ため、 その断面積を小さくすることができない。 このために、 トラック 幅を小さくすると逆に磁極の厚みが大きくなる傾向がある。 例えば、 幅 方向が 1 . 5 μ mのトラック幅のインダクティブ素子の磁極は、 3 /ί Πΐ 以上と厚い構造を必要とする。 このためトラック幅方向の公差を十分小 さく保つことが大きな課題となっている。 また、 磁極の断面形状の高さ/幅で規定されるァスぺク ト比が極端に 1から大きな値となると、 構造的な磁気抵抗が大きくなるとともに、 磁 極の磁気異方性を一方向にそろえることが難しくなり、 極が効果的に磁 束を通さなくなる。 磁極の記録ギャップから放出される磁界強度が弱く なると、 以前に記録した磁化情報をオーバーライ トする特性が悪化し、 記録した磁化の遷移長が長くなり分解能が低下し、 媒体起因のノイズ成 分が大きくなり、 磁気ディスク装置として必要な信号 S Z Nを確保する ことが難しくなる。 However, the inductive element, which is a recording element, cannot pass through a magnetic flux necessary for reversing the magnetization of the magnetic layer of the magnetic disk, so that its cross-sectional area cannot be reduced. For this reason, when the track width is reduced, the thickness of the magnetic pole tends to increase. For example, the magnetic pole of an inductive element having a track width of 1.5 μm in the width direction requires a thick structure of 3 / ί ί or more. For this reason, maintaining a sufficiently small tolerance in the track width direction is a major issue. Also, when the aspect ratio defined by the height / width of the magnetic pole cross-sectional shape becomes extremely large from 1, the structural magnetic resistance increases and the magnetic anisotropy of the magnetic pole decreases. Orientation becomes difficult and the poles do not effectively pass magnetic flux. When the intensity of the magnetic field emitted from the recording gap of the magnetic pole is weakened, the characteristics of overwriting previously recorded magnetization information are deteriorated, the transition length of the recorded magnetization is increased, the resolution is reduced, and noise components caused by the medium are reduced. And it becomes difficult to secure the signal SZN required for a magnetic disk drive.
磁極のトラック幅を小さく しても、 磁極の磁気抵抗を低下させない技 術として、磁極材料に飽和磁束密度の高い材料を用いて磁極の必要断面 積を減少させる方法と、 磁極の先端部の断面形状だけを小さく絞る方法 が考案されている。 ただし、 現状の F e濃度を高めた N i F e合金の飽 和磁束密度を大きく超える磁性材料を作成する技術が確立していない ことと、 先端部の断面形状だけを小さくするためには、 複雑でタク トの 長いプロセスを必要とするために、 製造コス トが高くなる欠点がある。 従来技術では、 磁極のトラック幅方向の寸法には下限があり、 特に、 0 . 7 μ m以下のトラック幅で十分な信号 S Z Nを確保することができ なかった。 かかる問題を解決するために、 特開平 7— 1 9 2 2 2 6号公 報に開示された.技術では、 磁極のトラック幅をトラックピッチよりも大 きな寸法にした磁気ディスク装置が提案されている。 この技術では磁極 のトラック幅寸法の下限を超える高トラック密度の磁気ディスク装置 を実現する可能性があるものの、 逆に再生へッドのトラック幅寸法をト ラックピッチに比べて極端に小さくする必要がある。 小さなトラック幅 寸法の再生へッドでは小さな再生出力しか得られないために、 この技術 を用いてトラック密度を高めるには， 再生へッドを改良する技術を必要 とする点が問題として残っていた。 このため、 十分な磁界強度を発生する広い磁極幅の記録素子と十分な 再生感度を有する広い再生幅の再生素子とを用いるとともに、 データ ト ラックの幅を狭く して磁気ディスク装置の記録密度を向上する技術の 開発が望まれていた。 As a technology that does not reduce the magnetic resistance of the magnetic pole even if the track width of the magnetic pole is reduced, a method of reducing the required cross-sectional area of the magnetic pole by using a material with a high saturation magnetic flux density for the magnetic pole material and a cross-section of the tip of the magnetic pole A method of narrowing down only the shape has been devised. However, there is no established technology to create magnetic materials that greatly exceed the saturation magnetic flux density of the current Ni Fe alloy with increased Fe concentration. The disadvantage is that the production costs are high due to the need for complex and long-acting processes. In the conventional technology, there is a lower limit to the dimension of the magnetic pole in the track width direction. In particular, a sufficient signal SZN cannot be secured with a track width of 0.7 μm or less. In order to solve such a problem, it has been disclosed in Japanese Patent Application Laid-Open Publication No. Hei 7-192 226. In the technology, a magnetic disk drive in which the track width of the magnetic pole is made larger than the track pitch has been proposed. ing. Although this technology may realize a magnetic disk drive with a high track density exceeding the lower limit of the track width of the magnetic pole, it is necessary to make the track width of the reproducing head extremely small compared to the track pitch. There is. The problem remains that a technique for improving the playback head is needed to increase the track density using this technique, because a playback head with a small track width can provide only a small playback output. Was. For this reason, a recording element having a wide magnetic pole width which generates a sufficient magnetic field strength and a reproducing element having a wide reproducing width having a sufficient reproducing sensitivity are used, and the recording density of the magnetic disk drive is reduced by reducing the width of the data track. The development of improved technology was desired.
発明の開示 Disclosure of the invention
上記問題点は、 記録素子で形成される記録トラック幅をトラックピッ チよりも大きな構成とするとともに、 磁気ディスクの半径方向へ 1 トラ ックずつずらしながら順番に記録を行う技術を用いることで解決する ことができる。  The above-mentioned problems are solved by using a technology in which the recording track width formed by the recording elements is made larger than the track pitch, and recording is performed sequentially while shifting one track at a time in the radial direction of the magnetic disk. can do.
また、記録素子で形成される消去トラック幅をトラックピッチの整数 倍の構成とするとともに、 磁気ディスクの半径方向へ 1 トラックずつず らしながら順番に記録を行う技術を用いることによっても解決するこ とができる。  Also, the problem can be solved by using a technique in which the erase track width formed by the recording elements is set to an integral multiple of the track pitch and recording is performed sequentially while shifting one track in the radial direction of the magnetic disk. Can be.
また、 記録素子の幾何学幅を再生素子の幾何学幅の 2倍以上の構成ど するとともに、磁気ディスクの半径方向へ 1 トラックずつずらしながら 順番に記録を行う技術を用いることによっても解決することができる。 このとき、 スリップ先データテーブルを備えて物理ァドレスを交替さ せる技術を併用するによって、 上記問題点を解決するとともに本技術を 用いた磁気ディスク装置のパフォーマンス性能を向上させることがで きる。 さらに、 ユーザーからの指示要求やマイクロプログラムの割込み 要求に応じてスリ ップ先データテーブルのデフラグメンテーション処 理を実施することによって、 使用初期のパフォーマンス性能を長期にわ たり維持することができる。  Another solution is to use a configuration in which the geometric width of the recording element is at least twice the geometric width of the reproducing element, and using the technology of recording sequentially while shifting one track in the radial direction of the magnetic disk. Can be. At this time, by using a technique for replacing a physical address with a slip destination data table, the above problems can be solved and the performance performance of a magnetic disk device using the present technique can be improved. Furthermore, by performing defragmentation of the slip destination data table in response to an instruction request from a user or an interrupt request from a microprogram, the performance performance at the initial use can be maintained for a long time.
このとき、 複数のゾーン毎にトラックピッチの異なる複数の領域に分 離することによって、従来の磁気ディスク装置と同等のパフォーマンス 性能を発揮する領域と、 記録密度が倍以上となる領域とを一台の磁気デ イスク装置の中で共有することができる。 さらに、 トラックピッチの異 なる複数の領域の境界を、 ユーザーが任意に設定できる機能を備えるこ とによって、 個々のアプリケーションに応じてパフォーマンスを高める ように最適化を行うことができる。 さらに、 トラックピッチの広い領域 にオペレーショ ンシステムがファイルを管理するファイルァロケーシ ョンデータを格納する機能を備えることによって、 オペレーションシス テムのディスク入出力のパフォーマンス性能を高めることができる。 図面の簡単な説明 At this time, by separating into a plurality of areas having different track pitches for each of a plurality of zones, one area having the same performance performance as the conventional magnetic disk drive and one area where the recording density is more than doubled. Magnetic de It can be shared in the disk device. In addition, by providing a function that allows the user to arbitrarily set the boundaries of multiple areas with different track pitches, optimization can be performed to improve performance according to individual applications. In addition, by providing the operating system with a function to store file allocation data for managing files in a wide area of track pitch, it is possible to improve the disk input / output performance of the operating system. BRIEF DESCRIPTION OF THE FIGURES
図 1は、 本発明の磁気ディスク装置の第 1の実施例における， 記録お よび再生素子の幅と トラックピッチとの関係を説明する図である。 図 2は、 従来の磁気ディスク装置の実施例における， 記録および再生 素子の幅と トラックピッチとの関係を説明する図である。  FIG. 1 is a diagram for explaining the relationship between the width of a recording / reproducing element and a track pitch in a first embodiment of the magnetic disk drive of the present invention. FIG. 2 is a diagram for explaining the relationship between the width of the recording and reproducing elements and the track pitch in the embodiment of the conventional magnetic disk drive.
図 3は、 磁気ディスク装置の概略的な構成の一例を説明する断面図で ある。  FIG. 3 is a cross-sectional view illustrating an example of a schematic configuration of a magnetic disk drive.
図 4は、 磁気ディスク装置の概略的な構成の一例を説明する平面図で ある。  FIG. 4 is a plan view illustrating an example of a schematic configuration of a magnetic disk drive.
図 5は、 磁気ディスク装置の一部分を上面から見た模式図である。 図 6は、 磁気ディスク装置のへッド部分を上面から透視した模式図で ある。  FIG. 5 is a schematic view of a part of the magnetic disk drive as viewed from above. FIG. 6 is a schematic view of the head portion of the magnetic disk drive as seen through from above.
図 7は、 本発明の磁気ディスク装置の第 2の実施例における， 記録お よび再生素子の幅と トラックピッチとの関係を説明する図である。 図 8は、 オーバーライ ト特性と記録素子幅との関係を説明する図であ る。  FIG. 7 is a diagram for explaining the relationship between the width of the recording / reproducing element and the track pitch in the second embodiment of the magnetic disk drive of the present invention. FIG. 8 is a diagram illustrating the relationship between the overwrite characteristics and the print element width.
図 9は、 本発明の磁気ディスク装置の第 3の実施例における， 再生素 子幅と記録素子幅との幾何学的な関係を説明する図である。 図 1 0は、 実効記録トラック幅および実効消去トラック幅と記録素子 幅との関係を説明する図である。 FIG. 9 is a diagram for explaining the geometrical relationship between the reproducing element width and the recording element width in the third embodiment of the magnetic disk drive of the present invention. FIG. 10 is a diagram for explaining the relationship between the effective recording track width, the effective erase track width, and the recording element width.
図 1 1は、 本発明の磁気ディスク装置の第 4の実施例における， 記録 および消去トラック幅と トラックピツチとの関係を説明する図である。 図 1 2は、本発明の磁気ディスク装置に新しいデータを記録する際の， 磁化情報を追加した様子とスリップ先データテーブルの内容を更新す る工程を説明する図である。  FIG. 11 is a diagram for explaining the relationship between the recording and erasing track width and the track pitch in the fourth embodiment of the magnetic disk drive of the present invention. FIG. 12 is a diagram for explaining a state in which magnetization information is added and a step of updating the contents of the slip destination data table when recording new data in the magnetic disk device of the present invention.
図 1 3は、本発明の磁気ディスク装置に上書きデータを記録する際の， 磁化情報を追加した様子とスリ ップ先データテーブルの内容を更新す る工程を説明する図である。  FIG. 13 is a diagram for explaining a state in which magnetization information is added and a step of updating the contents of the slip destination data table when overwriting data is recorded on the magnetic disk device of the present invention.
図 1 4は、本発明の磁気ディスク装置のスリップ先データテーブルの， デフラグメンテーシヨン処理工程を説明する図である。  FIG. 14 is a diagram illustrating a defragmentation processing step of the slip destination data table of the magnetic disk device of the present invention.
図 1 5は、 本発明の磁気ディスク装置の一つの実施例において， 磁気 ディスクの外周側のゾーン領域をトラックピッチの方が記録素子幅よ りも広い領域に設定したことを説明する図である。  FIG. 15 is a diagram for explaining that, in one embodiment of the magnetic disk drive of the present invention, the zone area on the outer peripheral side of the magnetic disk is set so that the track pitch is wider than the recording element width. .
図 1 6は、 本発明の磁気ディスク装置の一つの実施例において， トラ ックピッチを広げた領域における記録おょぴ再生素子の幅と トラック ピッチとの関係を説明する図である。  FIG. 16 is a view for explaining the relationship between the width of the recording / reproducing element and the track pitch in an area where the track pitch is widened in one embodiment of the magnetic disk drive of the present invention.
図 1 7は、 本発明の磁気ディスク装置の一つの実施例において， 磁気 ディスクの各ゾーンの一部の領域をトラックピッチの方が記録素子幅 よりも広い領域に設定したことを説明する図である。 発明を実施するための最良の形態  FIG. 17 is a diagram for explaining that in one embodiment of the magnetic disk drive of the present invention, a partial area of each zone of the magnetic disk is set to an area where the track pitch is wider than the recording element width. is there. BEST MODE FOR CARRYING OUT THE INVENTION
く実施例 1 >本発明の磁気ディスク装置の基本的な構成は、 図 3 , 図 4， 図 5を用いて従来の技術の項で説明を行った形態とほぼ同じである。 記 録および再生素子の幅と トラックピッチとの関係を、 本発明の 1例を示 した図 1と従来技術の 1例を示した図 2を比較しながら、 本発明の実施 の形態と特徴について説明する。 図 1と図 2においてへッドはディスク に対して相対的に図面の左から右に移動しながら磁化情報の記録およ び再生を行う。 図中では記録素子 6 2もしくは記録素子 6 4の左側のパ ターンが新たに記録された磁化情報に相当し、 今回記録したトラック 7 1として表わしている。 これに対して、 記録素子 6 2もしくは記録素子Embodiment 1 The basic configuration of the magnetic disk drive of the present invention is almost the same as the embodiment described in the section of the prior art with reference to FIGS. 3, 4, and 5. FIG. The relationship between the width of the recording / reproducing element and the track pitch is shown as an example of the present invention. Embodiments and features of the present invention will be described by comparing FIG. 1 shown in FIG. 1 with FIG. 2 showing an example of the related art. In FIGS. 1 and 2, the head records and reproduces magnetization information while moving from left to right in the drawing relative to the disk. In the figure, the recording element 62 or the pattern on the left side of the recording element 64 corresponds to the newly recorded magnetization information, and is represented as the track 71 recorded this time. On the other hand, the recording element 62 or the recording element
6 4の右側のパターンが、 上書き消去される磁化情報であり、 両図中で は破棄可能なトラック 7 3として表している。 影響を受けないトラックThe pattern on the right side of 64 is the magnetization information to be overwritten and erased, and is shown as a discardable track 73 in both figures. Unaffected truck
7 4は、 記録素子 6 2もしくは記録素子 6 4の走行する領域から外れて いるために、 以前の磁化情報はそのまま維持される。 In the case of the recording element 62, since the recording element 62 or the recording element 64 is out of the traveling area, the previous magnetization information is maintained as it is.
図 1に示す本発明では、 図 2に示した従来技術に比べてトラックピッ チを約半分にしてあり、 単位面積あたり約 2倍のデータを記憶すること ができる。 本発明の再生素子 6 2は、 隣接トラックの磁化情報を再生し ないようにトラックピ.ツチよりも狭く した。 このため本発明の再生素子 6 2は、 従来技術の再生素子 6 1に比べて約半分の幅である。 これに対 して本発明の記録素子 6 4、 トラックピッチよりも広い構成とすること で、 従来技術の記録素子 6 2と同等な幅にできた。 これにより、 記録素 子 6 4は十分な強度の記録磁界を発生することができ、 本発明の磁気デ イスク装置は良好なオーバーライ ト特性と高い信号 S N比を実現する ことができた。  In the present invention shown in FIG. 1, the track pitch is reduced to about half that of the conventional technique shown in FIG. 2, and about twice the data can be stored per unit area. The reproducing element 62 of the present invention is made narrower than the track pitch so as not to reproduce the magnetization information of the adjacent track. For this reason, the reproducing element 62 of the present invention is about half as wide as the reproducing element 61 of the prior art. On the other hand, by making the recording element 64 of the present invention wider than the track pitch, the width can be made equivalent to that of the recording element 62 of the prior art. As a result, the recording element 64 was able to generate a recording magnetic field having a sufficient intensity, and the magnetic disk device of the present invention was able to achieve good overwrite characteristics and a high signal SN ratio.
本発明の磁気ディスク装置では、 トラックピッチよりも広い記録素子 6 4を備えた複合へッドを備えるために、 記録動作と共に隣接するトラ ックの磁化情報をトラックピッチ以下の幅に整形する動作を行うこと ができる。 すなわち、 記録時には図 1に示すようなヘッド位置でフォロ イング制御を行う。 前回記録したトラック 7 2のうち、 今回記録したト ラック 7 1に干渉する片側の領域が上書き消去されることにより、 再生 素子 6 2で磁化情報を再生するに十分な幅のデータトラック 7 2を形 成することができる。 また、 この位置関係を保ちながら記録を行うこと により、 逆側の隣接トラック 7 4との干渉を避けることができる。 In the magnetic disk drive of the present invention, in order to provide a composite head having a recording element 64 wider than the track pitch, an operation of shaping the magnetization information of the adjacent track to a width equal to or less than the track pitch together with the recording operation. It can be performed. That is, during recording, following control is performed at the head position as shown in FIG. By overwriting and erasing one area of the previously recorded track 72 that interferes with the track 71 recorded this time, The data track 72 having a width sufficient for reproducing the magnetization information by the element 62 can be formed. Also, by performing recording while maintaining this positional relationship, it is possible to avoid interference with the adjacent track 74 on the opposite side.
なお、 図 1に示す本発明では再生素子 6 2の幅をトラックピッチより も狭く しているが、 将来的に隣接トラックからの磁化情報を信号処理に よって分離する技術が進めば、 トラックピッチよりも広い幅とすること が可能である。 さらに、 隣接するトラックのコーディング方法を素にす ることによって、 2本のデータトラックを積極的に同時に再生して転送 速度を向上することも可能である。  Although the width of the reproducing element 62 is narrower than the track pitch in the present invention shown in FIG. 1, if the technology for separating magnetization information from adjacent tracks by signal processing in the future progresses, the width of the reproducing element 62 will be smaller than the track pitch. Can also be wide. Furthermore, by using a simple coding method for adjacent tracks, it is possible to positively reproduce two data tracks at the same time and improve the transfer speed.
次に本発明の第 2の実施形態として、記録および再生素子の幅と トラ ックピッチとの関係を図 7に示す。 この磁気ディスク装置の複合へッド は、 図 7に示すようにトラックピッチの約 3倍に相当する記録素子 6 6 を備えている。 このため、 新たな磁化情報の記録に伴って上書き消去さ れるパターンが、 破棄可能なトラック 7 3として示すようにトラッグ 2 本分の幅になる。 この実施形態のようにトラックピッチの約 3倍の幅の 記録素子 6 6を用いることによって、 より狭いトラックピッチの磁気デ イスク装置が実現できる。 また、 さらなる高トラック密度の磁気ディス ク装置を実現するために、 記録素子幅と トラックピッチの比を、 4， 5， 6と大きくすることも可能である。  Next, as a second embodiment of the present invention, the relationship between the width of the recording / reproducing element and the track pitch is shown in FIG. As shown in FIG. 7, the composite head of this magnetic disk drive has a recording element 66 equivalent to about three times the track pitch. For this reason, the pattern to be overwritten and erased with the recording of new magnetization information has a width of two tracks as shown as a discardable track 73. By using the recording element 66 having a width approximately three times the track pitch as in this embodiment, a magnetic disk device with a narrower track pitch can be realized. In addition, the ratio between the recording element width and the track pitch can be increased to 4, 5, and 6 to realize a magnetic disk device with a higher track density.
以上に説明したいずれの実施形態においても、 ディスクの半径方向の 1方向に順に記録を行うことによって、 狭いトラックピッチに対応する データトラックを正しく形成していくことができる。 本発明により。 デ ータのシリアル転送要求が多い画像の保存用に特に適しだ、 安価で大容 量な磁気ディスク装置を提供することができる。 本発明の磁気ディスク 装置に、画像の転送の単位に応じたダミートラックを設けることにより、 パフォーマンス性能を格段に向上させることができる。 例えば、 転送の 単位であるプロック容量を、 画像の 1 0秒分の容量程度に大きくするこ どによって、 ダミートラックによるフォーマツト効率の低下を押さえつ つ、 従来の磁気ディスク装置と同等のランダムアクセス性能を有する磁 気ディスク装置を実現することができる。 さらに、 転送の単位を可変ブ ロックとし、 ブロックの大きさを録画した画像のつなぎ目に対応させ ることで、 ダミートラックによるフォーマツト効率の低下をほとんど無 視できるほどに小さくすることができる。 In any of the embodiments described above, by sequentially performing recording in one radial direction of the disk, data tracks corresponding to narrow track pitches can be formed correctly. According to the invention. It is possible to provide an inexpensive and large-capacity magnetic disk device that is particularly suitable for storing images that require a large number of serial data transfer requests. By providing the magnetic disk device of the present invention with a dummy track corresponding to the unit of image transfer, performance performance can be remarkably improved. For example, transfer By increasing the block capacity, which is a unit, to a capacity of about 10 seconds for an image, it is possible to reduce the formatting efficiency due to dummy tracks, and to achieve magnetic access with the same random access performance as conventional magnetic disk drives. A disk device can be realized. Furthermore, by setting the transfer unit to be a variable block and making the size of the block correspond to the joint of the recorded images, it is possible to reduce the formatting efficiency due to the dummy track so as to be almost negligible.
記録素子をトラックピッチよりも広くする方式として、 幅広のサーボ パターンを形成するためにトラックピッチよりも幅広の記録素子をサ ーボパターンの形成時に用いる技術が、特開平 1— 9 4 5 7 4号公報や 特開平 5— 2 9 8 8 4 0号公報に開示されている。 また、 記録素子をず らしながら.用いる方式として、 磁気ディスクの磁化情報を狭ピッチでず らしながら消去する技術が、 特開昭 6 3 - 3 2 7 0 5号公報に開示され ている。 また、 素子幅がトラックピッチよりも広い構成となる方式とし て、 2モードフロッピー装置向けに複数の素子のうち下位モードに対応 する素子の幅を上位モードのトラックピッチよりも広くする技術が、 特 開平 1— 2 5 8 2 0 9号公報ゃ特開平 5— 2 8 4 2 7号公報に開示さ れている。 ここに示したいずれの技術も、 データトラックを記録する素 子がドラックピッチよりも広い構成ではなく、 隣のデータトラックを重 ね書きする方式を用いていない。 このため、 記録素子の磁極幅よりもト ラックピッチを小さくすることができないため、 本発明の技術とは根本 的に異なるものである。  As a method of making the recording element wider than the track pitch, Japanese Patent Application Laid-Open No. 1-94557 discloses a technique in which a recording element wider than the track pitch is used for forming a servo pattern in order to form a wide servo pattern. And Japanese Patent Application Laid-Open No. Hei 5-292840. Japanese Patent Application Laid-Open No. 63-32705 discloses a technique for erasing the magnetic information of a magnetic disk while shifting it at a narrow pitch as a method of using the recording element while shifting it. In addition, as a method in which the element width is wider than the track pitch, a technique for making the width of the element corresponding to the lower mode out of a plurality of elements wider than the track pitch of the upper mode for a two-mode floppy device is a special feature. It is disclosed in Japanese Unexamined Patent Publication No. Hei. None of the technologies shown here has a configuration in which the elements for recording data tracks are wider than the drag pitch, and does not use a method of overwriting adjacent data tracks. For this reason, the track pitch cannot be made smaller than the magnetic pole width of the recording element, which is fundamentally different from the technique of the present invention.
<実施例 2〉本発明の磁気ディスク装置を、 より多くの用途に適したパ フォーマンス性能を持たせるために、 スリ ップ先データテーブルを備え て、セクタ単位ごともしくはトラック単位ごとに交替処理を行うことが できる。 ディスク上の磁化情報の形成過程とスリップ先データテープ ルの更新過程について、 新しいデータを記録する工程を図 1 2に、 上書 き.データを記録する工程を図 1 3に示す。 <Embodiment 2> In order to provide the magnetic disk drive of the present invention with performance performance suitable for more applications, a slip destination data table is provided, and replacement processing is performed for each sector or each track. It can be performed. Formation process of magnetization information on disk and data tape at slip destination Figure 12 shows the process of recording new data and Figure 13 shows the process of recording data.
図 1 2はディスクのトラック 1 0 1と トラック 1 0 2まで既に情報 が記録されていて、 トラック 1 0 3以降には有効なデータが記録されて いない磁化状態を示している。 最終ボインタはトラック 1 0 2を指し示 している。 スリップ （交替） 先データテーブルの値は 0で初期化されて いて、 どのトラックも交替処理が行われていないことを表している。 こ こで、 新しいデータを記録する際には、 最終ポインタ （前回最後に記録 を行ったトラック番号） の値に従い、 トラック 1 0 3と トラック 1 0 4 に記録素子 6 4がまたがる位置にフォロイングを行いながら、磁化情報 の記録を行う。 記録が終了した時点で最終ボインタの値を 1 0 2から 1 0 3へと更新する。  FIG. 12 shows a magnetization state in which information has already been recorded up to track 101 and track 102 of the disk, and no effective data has been recorded after track 103. The last bottler points to track 102. The value of the slip (replacement) destination data table is initialized to 0, indicating that no track has been replaced. Here, when recording new data, following is performed according to the value of the last pointer (the last recorded track number) at the position where the recording element 64 extends over tracks 103 and 104. While recording, record the magnetization information. When the recording is completed, the value of the last pointer is updated from 102 to 103.
図 1 3はディスクのトラック 1 0 1からトラック 1 0 3まで既に情 報が記録されていて、 トラック 1 0 4以降には有効なデータが記録され ていない磁化状態を示している。最終ボインタはトラック 1 0 3を指し 示している。 ここで、 トラック 1 0 2に対して新しいデータを上書きす る際には、 最終ポインタの値に従って、 トラック 1 0 4と トラック 1 0 5に記録素子 6 4がまたがる位置にフォロイングを行いながら磁化情 報の記録を行う。 記録が終了した時点で最終ボインタの値を 1 0 3から 1 0 4へと更新し、 さらにスリップ先データテーブルのトラック番号 1 0 2の値を 0から 2へと更新し、 トラック番号 1 0 4の値を 0から被参 照フラグの値 Xを書き込む。 後にトラック 1 0 2を再生する際には、 ま ずスリップ先データテーブルのトラック番号 1 0 2の項目が 2である ことを参照し、 1 0 2に 2を加えたトラック 1 0 4を再生することによ り、 上書きした新しいデータを正しく取り出すことができる。  FIG. 13 shows a magnetized state in which information has already been recorded from track 101 to track 103 of the disk, and no effective data has been recorded after track 104. The last bottler points to track 103. Here, when overwriting the new data on the track 102, the magnetizing information is written while following the position of the recording element 64 over the tracks 104 and 105 according to the value of the last pointer. Record information. When the recording is completed, the value of the last pointer is updated from 103 to 104, and the value of the track number 102 in the slip destination data table is updated from 0 to 2, and the track number 104 Write the value X of the referenced flag from 0 to 0. When playing back the track 102 later, first, refer to the fact that the item of the track number 102 in the slip destination data table is 2 and play the track 104 obtained by adding 2 to 102. By doing so, new data that has been overwritten can be correctly retrieved.
本発明にスリップ先データテーブルを備えた磁気ディスク装置では、 任意のトラックに対して任意回数の上書き処理を行うことが可能であ り.、 従来の磁気ディスク装置とほぼ同等のランダムアクセス性能を発揮 することができる。 本実施例では、 スリップ先データテーブルをトラッ ク単位で設けることで、 ハードウエアやコントローラーの負荷を軽減し ている。 よりディスクの面積を効率的に活用するために、 スリ ップ先デ ータテーブルをセクタ単位で設けて高度な交替処理を行うことも可能 である。 In the magnetic disk drive provided with the slip destination data table according to the present invention, An arbitrary number of overwrite processes can be performed on an arbitrary track. Random access performance almost equivalent to that of a conventional magnetic disk drive can be exhibited. In this embodiment, the load on the hardware and the controller is reduced by providing the slip destination data table for each track. In order to use the disk area more efficiently, it is possible to provide a slip destination data table for each sector to perform advanced replacement processing.
本発明のスリップ先データテーブルを備えた磁気ディスク装置では、 定期的にスリップ先データテーブルの内容のデフラグメンテーション を実施することにより、 交替処理が行われてアクセスが行われなくなつ たトラックもしくはセクタを再ぴ使用可能な領城に復活させることが できる。 ここでは、 トラック 1 0 2がトラック 1 0 4に交替された、 図 1 3に示すような磁化状態を対象に説明を行う。 この時のデフラグメン テーシヨン処理工程に伴う、 スリ ップ先データテーブルの更新過程を、 図 1 4に示す。  In the magnetic disk drive provided with the slip destination data table of the present invention, by periodically defragmenting the contents of the slip destination data table, the tracks or sectors that have been replaced and no longer accessed can be identified. It can be restored to a reusable territory. Here, a description will be given of a magnetization state as shown in FIG. 13 in which the track 102 is replaced by the track 104. Figure 14 shows the process of updating the slip destination data table that accompanies the defragmentation process at this time.
まず工程 1では、 トラック 1 0 3のデ一タを再生して、 この再生した 情報をトラック 1 0 2と トラック 1 0 3にまたがって記録する。 スリ ツ プ先データテーブルの値はトラック番号 1 0 3の値を 0から一 1へと 更新する。 以降、 トラック 1 0 3を再生する際には、 スリップ先データ テーブルの項目が一 1であるから、 1 0 3に一 1を加えたトラック 1 0 2を再生することになる。 次に工程 2では、 トラック 1 0 4のデータを 再生して、 この再生した情報をトラック 1 0 3と トラック 1 0 4にまた がって記録する、 スリップ先データテーブルの値は参照元のトラック番 号 1 0 2の値を 2から 1へと更新する。 以降、 トラック 1 0 2を再生す る際には、 スリップ先データテーブルの項目が 1であるから、 1 0 2に 1を加えたトラック 1 0 3を再生することになる。 最後に工程 3で、 最 終ボインタの値を 1 0 4から 1 0 3に更新し、 スリップ先データテープ ルのトラック番号 1 0 4の値を被参照フラグの から 0へと更新して、 デフラグメンテーシヨン処理が終了する。 この処理により、 新たにトラ ック 1 0 4が使用可能なトラックとして復活する。 First, in step 1, the data of the track 103 is reproduced, and the reproduced information is recorded over the track 102 and the track 103. The value of the slip destination data table updates the value of the track number 103 from 0 to 1 1. Thereafter, when the track 103 is reproduced, since the item in the slip destination data table is 11, the track 102 obtained by adding 1 to 103 is reproduced. Next, in step 2, the data of the track 104 is reproduced, and the reproduced information is recorded over the track 103 and the track 104. The value of the slip destination data table is the reference source track. Update the value of the number 102 from 1 to 2. Thereafter, when the track 102 is reproduced, since the item of the slip destination data table is 1, the track 103 obtained by adding 1 to 102 is reproduced. Finally, in step 3, The value of the last pointer is updated from 104 to 103, the value of the track number 104 of the data table of the slip destination is updated from to of the referenced flag to 0, and the defragmentation process ends. By this processing, the track 104 is restored as a usable track.
デフラグメンテーシヨンを行うタイミングは、 あらかじめユーザーが 設定した時間間隔で、 ， ユーザーからの指示による任意時間でもよい。 通常のデフラグメンテーション処理は、 ユーザーからのアクセス要求が 一定時間以上無い時刻に行われるが、 本発明の磁気ディスク装置では処 理途中でもユーザーからのアクセス要求に応答することが可能である。 <実施例 3 >本発明の磁気ディスク装置のパフォーマンス性能を、 さら に高いものとするためにディスクの領域を、 図 1 5にゾーン 1 5 3から ゾーン 1 5 6まで、 トラック中のセクタ数の異なる 4つのゾーンを備え たディスクを例に説明を行う。 ディスクの外周側からゾーン 1 5 3には、 1 トラック中に 3 6 0のセクタが設けられていて、 順にゾーン 1 5 4に は 3 2 4、：ゾーン 1 5 5には 2 8 8、 ゾーン 1 5 6には 2 5 2のセクタ が設けられている。 ゾーン境界には、 外周と内周の隣接データがトラッ クのセクタ配置が異なることから、 相互に干渉することを避けてダミー トラックが設けられている。  The defragmentation may be performed at a time interval set by the user in advance, or at an arbitrary time according to an instruction from the user. The normal defragmentation process is performed at a time when there is no access request from the user for a certain period of time or longer. However, the magnetic disk device of the present invention can respond to the access request from the user even during the process. <Embodiment 3> In order to further enhance the performance performance of the magnetic disk drive of the present invention, the disk area is changed as shown in FIG. 15 from zone 15 3 to zone 15 6 in the number of sectors in the track. The following explanation uses a disk with four different zones as an example. From the outer circumference of the disk, zone 1553 has 3600 sectors in one track, and zone 1554 has 324, in that order: zone155 has 288, zone 1556 is provided with 252 sectors. A dummy track is provided at the zone boundary to avoid interference between adjacent data on the outer and inner tracks in the sector arrangement of the track.
ディスク内周側の 3つのゾーン 1 5 4からゾーン 1 5 6までは、 図 1 に示したような記録素子 6 4および再生素子 6 2の幅と トラックピッ チとの関係になるように、狭トラックピッチ領域 1 5 2に設定している。 これに対して、 外周側のゾーン 1 5 3では、 図 1 6に示したような記録 素子 6 8およぴ再生素子 6 7の幅と トラックピッチとの関係になるよ うに、 広トラックピッチ領域 1 5 1に設定した。 このような設定にする ことによって、 ゾーン 1 5 3ではスリップ先データテーブルを用いた交 替処理を行うことなく、 直接に上書きしてデータを置き換えることがで きる。 このゾーン 1 5 3に、 特に頻繁に置き換えを行う可能性のあるデ ータを配置することによって、 交替処理の繰り返しによる記録効率の低 下を避けることができる。 例えば、 オペレーションシステムがファイル を管理するためのファイルァロケーションテーブルや、 R AMディスク ファイル、 システムのスワップファイルなどが、 頻繁に置き換えを行う 可能性のあるデータである。 このように、 特定のデータを優先的にゾー ン 1 5 3に再配置する処理は、 オペレーションシステムよりも上位のァ プリケーションによって実現することができる。 The three zones 154 to 156 on the inner circumference side of the disk are narrow so that the width of the recording element 64 and the reproducing element 62 as shown in FIG. 1 is related to the track pitch. The track pitch area is set to 152. On the other hand, in the outer zone 15 3, the wide track pitch area is set so that the relationship between the width of the recording element 68 and the reproducing element 67 and the track pitch as shown in FIG. 16 is obtained. Set to 1 5 1 With this setting, data can be directly overwritten and replaced in zone 15 3 without performing replacement processing using the slip destination data table. Wear. By arranging data that may be replaced frequently in this zone 153, it is possible to avoid a decrease in recording efficiency due to repetition of the replacement process. For example, file allocation tables for operating systems to manage files, RAM disk files, and system swap files are data that can be replaced frequently. As described above, the process of preferentially relocating specific data to the zone 153 can be realized by an application higher than the operation system.
また、 広トラックピッチ領域 1 5 1と狭トラックピッチ領域 1 5 2と の境界は、 工場出荷前にサーボトラックライタのような特殊な装置で割 り当てるものではなく、 磁気ディスク装置内のマイク口プログラムによ つて実現する機能である。 工場から磁気ディスクを出荷した後に、 ユー ザ一が任意に変更できる機能を備えることで、 個々の使用環境で最高の パフォーマンスを発揮する磁気デイスク装置に最適化が可能となる。 ディスクの領域を、 トラックピッチの異なるいくつかの領域に分離す る第 2の実施例として、 备ゾーンの一部の面積を、 トラックピッチの広 い領域に割り当てることができる。 図 1 7に示したディスクは、 図 1 5 のディスクと同様にゾーン 1 5 3からゾーン 1 5 6まで、 トラック中の セクタ数の異なる 4つのゾーンを備えている。 内周側のゾーン 1 5 6で は、 2 5 2セクタの全てが狭トラックピッチ領域 1 6 2に割り当てられ ている。 ディスク外周側の 3つのゾーン 1 5 3からゾーン 1 5 5までは、 先頭から 2 5 2セクタ分の領域が、 狭トラックピッチ領域 1 6 2に割り 当てられていて、 残りのセクタが広トラックピッチ領域 1 6 1に割り当 てられている。 この設定により、 狭トラックピッチ領域 1 6 2の 1 トラ ック中のセクタ数を、外周から内周のゾーンにわたって同一数にできる。 このため、 スリップ先データテーブルをトラック単位で設け、 ハードウ エアゃコントローラーの負荷を軽減することができる。 In addition, the boundary between the wide track pitch area 15 1 and the narrow track pitch area 15 2 is not assigned by a special device such as a servo track writer before shipment from the factory. This function is implemented by a program. By providing a function that can be changed arbitrarily by the user after the magnetic disk is shipped from the factory, it is possible to optimize the magnetic disk device that performs best in each usage environment. As a second embodiment in which the disk area is divided into several areas having different track pitches, a part of the area of the 备 zone can be allocated to an area having a wide track pitch. The disk shown in FIG. 17 has four zones with different numbers of sectors in the tracks from zone 153 to zone 156 as in the disk shown in FIG. In the inner zone 156, all of the 252 sectors are allocated to the narrow track pitch area 162. From the three Zones 15 3 to 15 5 on the outer circumference of the disk, the area of the first 25 2 sectors is allocated to the narrow track pitch area 16 2, and the remaining sectors are wide track pitch. Allocated to area 16 1. With this setting, the number of sectors in one track of the narrow track pitch area 162 can be the same from the outer zone to the inner zone. For this reason, a slip destination data table is provided for each track, and hardware The load on the air controller can be reduced.
ぐ実施例 4〉実効記録トラック幅は、 実際にディスクに記録された磁化 パターンの半値幅で規定することができる。 また、 実効消去トラック幅 は、 実際にディスクに記録された磁化パターンで上書き消去された下地 トラックの半値幅で規定することができる。 記録素子幅が約 1 . 6 ;ζ πι のヘッドに対して、 イオンミリング技術により約 1 . 4 i m , 1 . 1 μ m , 0 . 9 μ m幅に狭くするトリミング処理を行った。 このヘッドにお いて、 実効記録トラック幅と実効消去トラック幅を実測した結果を、 各 へッドの記録素子の幾何学幅を横軸にして図 1 0のグラフに示す。 実効 消去トラック幅は実効記録トラック幅よりも広くなり、 その差は記録素 子の幾何学幅によらず約 0 . 5 μ mとほぼ一定であることを発見した。 このことは、 記録素子の幾何学幅を限りなく狭く しても、 実効消去トラ ック幅がある幅で残ることを示唆している。 Example 4> The effective recording track width can be defined by the half width of the magnetization pattern actually recorded on the disk. The effective erase track width can be defined by the half-value width of the underlying track overwritten and erased by the magnetization pattern actually recorded on the disk. A head having a recording element width of about 1.6; ζπι was subjected to a trimming process to narrow the width to about 1.4 im, 1.1 μm, and 0.9 μm by an ion milling technique. The graph of FIG. 10 shows the measured results of the effective recording track width and the effective erasing track width of this head, with the geometric width of the recording element of each head as the horizontal axis. We found that the effective erasure track width was wider than the effective recording track width, and the difference was almost constant at about 0.5 μm regardless of the geometric width of the recording element. This suggests that even if the geometric width of the recording element is reduced as much as possible, the effective erase track width remains at a certain width.
本発明の磁気ディスク装置は、 図 1 1に示すようにトラックピッチを 実効消去トラック幅の約半分とする構成のへッドを備える。 従来の磁気 ディスク装置では、 実効消去:トラック幅をトラックピッチと同等とする ために、 記録素子の幾何学幅を極端に狭くする必要があった。 本発明の 磁気ディスク装置は、 十分な記録磁界強度を発生できる幅の記録素子 6 9を備えることができ、 良好なォ一パーライ ト特性と高い信号 S Nを実 現することができた。 この磁気ディスク装置に実施例 1で説明を行った 順次記録や、 実施例 2で説明を行ったスリ ップ先データテーブルを用い る交替処理や、 実施例 3で説明を行った複数のトラックピッチの領域を 設定する技術を適用することによって、 さらにパフォーマンス性能に優 れた、 大容量の磁気ディスク装置を提供することができる。  As shown in FIG. 11, the magnetic disk drive of the present invention includes a head having a configuration in which the track pitch is set to about half of the effective erase track width. In a conventional magnetic disk drive, the geometric width of the recording element had to be extremely narrow in order to make the effective erase: track width equal to the track pitch. The magnetic disk device of the present invention was provided with the recording element 69 having a width capable of generating a sufficient recording magnetic field intensity, and was able to realize good overhead light characteristics and a high signal SN. Sequential recording described in the first embodiment, replacement processing using the slip destination data table described in the second embodiment, and multiple track pitches described in the third embodiment By applying the technology for setting the area of the disk, it is possible to provide a large-capacity magnetic disk device with even better performance performance.
<実施例 5 >磁気ディスク装置は、 古い磁化情報が書き込まれたデータ トラックの上に新しい磁化情報を上書き記録する直接オーバーライ ト 記録方式を採用している。 消去工程を必要とせずに古い磁化情報のマス クができるために、 高いパフォーマンス性能を実現することができる。 しかし、 わずかに残る古い磁化情報の成分は、 新しい磁化情報のクロッ ク周波数と同一であるために分離が難しく、 ノイズ成分として信号 S N を劣化させる直接要因になる。 新しい磁化情報の上書き記録の前後にお ける、 古い磁化情報の信号強度比はオーバーライ ト特性と呼ばれる。 こ のオーバーライ ト特性が小さいほど、 ノイズ成分も小さくなつて良好な 信号 S Nを得ることができる。 十分な信号 S Nを得るために必要な、 ォ 一バーライ ト特性のひとつの目標値は約一 3 0 d Bである。 <Embodiment 5> The magnetic disk drive uses a direct overwrite method that overwrites and records new magnetization information on a data track on which old magnetization information is written. The recording method is adopted. Since the old magnetization information can be masked without an erasing step, high performance performance can be realized. However, the component of the old magnetization information that remains slightly is difficult to separate because it is the same as the clock frequency of the new magnetization information, and is a direct factor that degrades the signal SN as a noise component. The signal intensity ratio of the old magnetization information before and after overwriting the new magnetization information is called the overwrite characteristic. The smaller the overwrite characteristic, the smaller the noise component and the better the signal SN. One target value of the overwrite characteristic required to obtain a sufficient signal SN is about 130 dB.
今回、 記録素子幅が約 1 . 6 /X mのヘッドに対して、 イオンミリング 技術により約 1 . 4 μ πι , 1 . 1 μ χα , 0 . 9 /z m幅に狭くするトリミ ング処理を行った。 このヘッドにおいて、 オーバーライ ト特性を実測し た結果を、 各へッドの記録素子の幾何学幅を横軸にして図 8のグラフに 示す。 オーバーライ ト特性は、 記録素子の幾何学幅が小さくなるほど悪 化することを発見した。 このとき、 一3 0 d B以下のオーバーライ ト特 性を示すヘッドの記録素子 幾何学幅は、 再生素子の幾何学幅の 2倍よ りも大きなへッドだけであった。  This time, a head with a recording element width of about 1.6 / Xm was trimmed to a width of about 1.4μππ, 1.1μχα, 0.9 / zm by ion milling technology. Was. The results of the actual measurement of the overwrite characteristics of this head are shown in the graph of FIG. 8 with the geometric width of the recording element of each head as the horizontal axis. We have found that the overwrite characteristics worsen as the geometric width of the recording element decreases. At this time, the geometric width of the recording element of the head exhibiting an overwrite characteristic of 30 dB or less was only a head larger than twice the geometric width of the reproducing element.
本発明の磁気ディスク装置は、 図 9に示すように記録素子 6 8の幾何 学幅を、 再生素子 6 7の幾何学幅の 2倍以上とする構成のへッドを備え る。 従来の磁気ディスク装置では、 記録素子の幾何学幅は再生素子の幾 何学幅の 1 . 2から 1 . 5倍程度に設定していた。 実効再生トラック幅 は再生素子の幾何学幅とほぼ同等になるが、 実効再生幅をトラックピッ チよりも狭くすることに伴って、 記録素子の幾何学幅を極端に狭くする 必要があった。 本発明の磁気ディスク装置は、 十分な記録磁界強度を発 生できる幅の記録素子 6 8を備えることができ、 良好なオーバーライ ト 特性と高い信号 S Nを実現することができた。 この磁気ディスク装置に 実施例 1で説明を行った順次記録や、 実施例 2で説明を行ったスリップ 先データテーブルを用いる交替処理や、 実施例 3で説明を行った複数の トラックピッチの領域を設定する技術を適用することによって、 さらに パフォーマンス性能に優れた、 大容量の磁気ディスク装置を提供するこ とができる。 産業上の利用可能性 As shown in FIG. 9, the magnetic disk drive of the present invention includes a head having a configuration in which the geometric width of the recording element 68 is at least twice the geometric width of the reproducing element 67. In the conventional magnetic disk drive, the geometric width of the recording element is set to be about 1.2 to 1.5 times the geometric width of the reproducing element. Although the effective reproduction track width is almost equal to the geometric width of the reproducing element, the geometric width of the recording element had to be extremely narrowed as the effective reproduction width became narrower than the track pitch. The magnetic disk device of the present invention was provided with the recording element 68 having a width capable of generating a sufficient recording magnetic field intensity, and was able to achieve good overwrite characteristics and high signal SN. This magnetic disk drive The sequential recording described in the first embodiment, the replacement process using the slip destination data table described in the second embodiment, and the technique of setting a plurality of track pitch areas described in the third embodiment are applied. By doing so, it is possible to provide a large-capacity magnetic disk device with even better performance performance. Industrial applicability
本発明は、 記録用素子と再生用素子が分離した複合へッドを用いたディ スク装置において、 トラックピッチを記録素子で形成される記録トラッ ク幅よりも小さな構成とすることにより、記録素子幅の狭小化に伴う記 録磁界強度の低下を避けることができるので、 トラック密度を高めた大 容量の磁気ディスク装置を実現することができる。 The present invention relates to a disk device using a composite head in which a recording element and a reproduction element are separated from each other by using a configuration in which a track pitch is smaller than a recording track width formed by the recording element. Since a decrease in the recording magnetic field intensity due to the narrowing of the width can be avoided, a large-capacity magnetic disk device with an increased track density can be realized.
また、 スリップ先データテーブルを備えることによって、 任意箇所の データを書き換え可能なランダムアクセス性能を有する磁気ディスク 装置を実現することができる。  Further, by providing the slip destination data table, it is possible to realize a magnetic disk device having random access performance capable of rewriting data at an arbitrary position.
さらに、 ディスクの一部分の領域のトラックピッチを広げて直接にデ ータの置き換えが可能な領域を設けることによって、 コントローラーの オーバーへッドが少ないパフォーマンス性能に優れた磁気ディスク装 置を実現することができる。  In addition, by increasing the track pitch in a part of the disk to provide an area where data can be directly replaced, a magnetic disk device with less performance overhead and less controller overhead can be realized. Can be.

Claims

請 求 の 範 囲 The scope of the claims
1 . 磁気ディスクに磁化情報を記録する記録素子と該磁気ディスクの磁 化情報を電気信号に変換する再生素子とを備える複合型へッドを用い た磁気ディスク装置の、 前記記録素子で形成される記録トラック幅がト ラックピッチよりも大きいへッドを備え、 前記磁気ディスクに磁化情報 を記録する際に該磁気ディスクの半径方向へずらしながら記録を行う 手段を有することを特徴とする磁気ディスク装置。 1. A magnetic disk device using a composite head including a recording element for recording magnetization information on a magnetic disk and a reproducing element for converting the magnetization information of the magnetic disk into an electric signal, wherein the recording element is formed by the recording element. A magnetic disk having a recording track width larger than a track pitch, and having means for performing recording while shifting magnetization information in a radial direction of the magnetic disk when recording magnetic information on the magnetic disk. apparatus.
2 . 上記磁気ディスクに磁化情報を記録する際の記録を行う手段が該磁 気ディスクの半径方向へ 1 トラックずつずらしながら順番に記録を行 うことを特徴とする請求項 1記載の磁気ディスク装置。  2. The magnetic disk drive according to claim 1, wherein the means for performing recording when recording the magnetization information on the magnetic disk performs recording sequentially while shifting one track at a time in the radial direction of the magnetic disk. .
3 . 上記記録素子の幾何学幅が前記再生素子の幾何学幅の 2倍以上であ るへッドを備えることを特徴とする請求項 1記載の磁気ディスク装置。 3. The magnetic disk drive according to claim 1, further comprising a head having a geometric width of the recording element that is at least twice the geometric width of the reproducing element.
4 . 上記記録素子で形^ ¾ざれる記録トラック幅がトラックピッチよりも 大きく、 かつ該記録素子で形成される記録トラック幅がトラックピッチ の 2倍よりも小さく、 かつ前記記録素子で形成される消去トラック幅が トラックピッチのおよそ 2倍であるヘッドを備えることを特徴とする 請求項 1記載の磁気ディスク装置。 4. The recording track width formed by the recording element is larger than the track pitch, the recording track width formed by the recording element is smaller than twice the track pitch, and formed by the recording element. 2. The magnetic disk drive according to claim 1, further comprising a head having an erase track width approximately twice the track pitch.
5 . 上記磁気ディスク上の物理ァドレスの交替先を管理するスリップ先 データテーブルを備え、 既に記録された情報を新たな情報で置き換える 際には前記スリップ先データテーブルを検索して更新することを特徴 とする請求項 1記載の磁気ディスク装置。  5. A slip destination data table for managing the replacement of physical addresses on the magnetic disk is provided, and when replacing already recorded information with new information, the slip destination data table is searched and updated. 2. The magnetic disk drive according to claim 1, wherein:
6 . 上記磁気ディスクがトラックピッチの異なる複数の領域に分離され ていることを特徴とする請求項 1記載の磁気ディスク装置。  6. The magnetic disk drive according to claim 1, wherein the magnetic disk is divided into a plurality of areas having different track pitches.
7 . 上記磁気ディスクが該磁気ディスクの半径ごとに 1 トラック中のセ クタ数が異なる複数のゾーンに分割されており、 かつ該ゾーンの少なく とも 1つのゾーンがさらにトラックピッチの異なる複数の領域に分離 されていることを特徴とする請求項 6記載の磁気ディスク装置。 7. The magnetic disk is divided into a plurality of zones in which the number of sectors in one track is different for each radius of the magnetic disk, and the number of zones is small. 7. The magnetic disk drive according to claim 6, wherein at least one zone is further divided into a plurality of regions having different track pitches.
8 . 上記トラックピッチの異なる複数の領域の境界を、 工場出荷後に ユーザーが設定できる機能を備えることを特徴とする請求項 6または 7記載の磁気ディスク装置。  8. The magnetic disk drive according to claim 6, further comprising a function of allowing a user to set boundaries between the plurality of areas having different track pitches after factory shipment.
9 . 上記トラックピッチの異なる複数の領域に、 オペレーショ ンシステ ムがファイルを管理するファイルァロケーションデータを格納する機能 を備えることを特徴とする請求項 6または 7記載の磁気ディスク装置。 9. The magnetic disk drive according to claim 6, wherein an operation system has a function of storing file allocation data for managing files in the plurality of areas having different track pitches.
1 0 . 磁気ディスクに磁化情報を記録する記録素子と該磁気ディスクの 磁化情報を電気信号に変換する再生素子とを備える複合型へッドを用 いた磁気ディスク装置の、 前記記録素子で形成される消去トラック幅が トラックピッチのおよそ整数倍となるへッドを備え、 前記磁気ディスク に磁化情報を記録する際に該磁気ディスクの半径方向へずらしながら 記録を行う手段を有することを特徴とする磁気ディスク装置。 10. A magnetic disk device using a composite head including a recording element for recording magnetization information on a magnetic disk and a reproducing element for converting the magnetization information of the magnetic disk into an electric signal, wherein the recording element is formed by the recording element. And a means for performing recording while shifting magnetization in the radial direction of the magnetic disk when recording magnetic information on the magnetic disk. Magnetic disk drive.
1 IV上記磁気ディスクに磁化情報を記録する際の記録を行う手段が該 磁気ディスクの半径方向へ 1 トラックずつずらしながら.順番に記録を 行うことを特徴とする請求項 1 0記載の磁気ディスク装置。  10.The magnetic disk drive according to claim 10, wherein the means for recording when recording the magnetization information on the magnetic disk performs recording sequentially while shifting one track at a time in the radial direction of the magnetic disk. .
1 2 . 上記記録素子の幾何学幅が前記再生素子の幾何学幅の 2倍以上で あるへッドを備えることを特徴とする請求項 1 0記載の磁気ディスク 装置。  12. The magnetic disk drive according to claim 10, further comprising a head having a geometric width of the recording element that is at least twice a geometric width of the reproducing element.
1 3 . 上記記録素子で形成される記録トラック幅がトラックピッチより も大きく、 かつ該記録素子で形成される記録トラック幅がトラックピッ チの 2倍よりも小さく、 かつ前記記録素子で形成される消去トラック幅 がトラックピッチのおよそ 2倍であるへッドを備えることを特徴とす る請求項 1 0記載の磁気ディスク装置。  13. The recording track width formed by the recording element is larger than the track pitch, and the recording track width formed by the recording element is smaller than twice the track pitch, and formed by the recording element. 10. The magnetic disk drive according to claim 10, further comprising a head having an erase track width approximately twice the track pitch.
1 4 . 磁気ディスク上の物理ァドレスの交替先を管理するスリップ先デ ータテーブルを備え、 既に記録された情報を新たな情報で置き換える際 には前記スリップ先データテーブルを検索して更新することを特徴と する請求項 1 0記載の磁気ディスク装置。 1 4. Slip destination data that manages the replacement of physical addresses on the magnetic disk 10. The magnetic disk drive according to claim 10, further comprising a data table, wherein when replacing the already recorded information with new information, the slip destination data table is searched and updated.
1 5 . ユーザ一からの指示要求もしくはタイマーによって起動するマイ クロプログラムの割り込み要求に応じて上記のスリップ先データテー プルのデフラグメンテーション処理を実施する機能を備えることを特 徴とする請求項 1 4記載の磁気ディスク装置。  15. The method according to claim 14, further comprising a function of executing the defragmentation process of the slip destination data tape in response to an instruction request from a user or an interrupt request of a microprogram activated by a timer. Magnetic disk unit.
1 6 . 上記磁気ディスクがトラックピッチの異なる複数の領域に分離さ れていることを特徴とする請求項 1 0記載の磁気ディスク装置。  16. The magnetic disk drive according to claim 10, wherein said magnetic disk is divided into a plurality of regions having different track pitches.
1 7 . 上記磁気ディスクが該磁気ディスクの半径ごとに 1 トラック中の セクタ数が異なる複数のゾーンに分割されており、 かつ該ゾーンの少な くとも 1つのゾーンがさらにトラックピッチの異なる複数の領城に分 離されていることを特徴とする請求項 1 6記載の磁気ディスク装置。 17. The magnetic disk is divided into a plurality of zones having different numbers of sectors in one track for each radius of the magnetic disk, and at least one of the zones further has a plurality of regions having different track pitches. 17. The magnetic disk drive according to claim 16, wherein the magnetic disk drive is separated from a castle.
1 8 . 上記トラックピッチの異なる複数の領域の境界を、 工場出荷後に ユーザーが設定できる機能を備えることを特徴とする請求項 1 6また は 1 7記載の磁気ディスク装置。 18. The magnetic disk drive according to claim 16 or 17, further comprising a function of allowing a user to set boundaries between the plurality of areas having different track pitches after factory shipment.
1 9 . 上記トラックピッチの異なる複数の領域に， オペレーショ ンシス テムがファイルを管理するファイルァロケーションデータを格納する 機能を備えることを特徴とする請求項 1 6または 1 7記載の磁気ディ スク装置。  19. The magnetic disk drive according to claim 16, wherein the operating system has a function of storing file allocation data for managing files in the plurality of areas having different track pitches.
PCT/JP1998/000884 1998-03-04 1998-03-04 Magnetic disc device WO1999045534A1 (en)

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JP2000535001A JP3689638B2 (en) 1998-03-04 1998-03-04 Magnetic disk unit
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KR10-2000-7009157A KR100479013B1 (en) 1998-03-04 1998-03-04 Magnetic disc device
US11/404,780 US7443625B2 (en) 1998-03-04 2006-04-17 Magnetic disk drive

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