GB2333176A - Disc drive servo system employing thermal signals - Google Patents

Disc drive servo system employing thermal signals

Info

Publication number
GB2333176A
GB2333176A GB9906721A GB9906721A GB2333176A GB 2333176 A GB2333176 A GB 2333176A GB 9906721 A GB9906721 A GB 9906721A GB 9906721 A GB9906721 A GB 9906721A GB 2333176 A GB2333176 A GB 2333176A
Authority
GB
United Kingdom
Prior art keywords
magnetoresistive element
disc
spacing
disc drive
user data
Prior art date
Legal status (The legal status 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 status listed.)
Granted
Application number
GB9906721A
Other versions
GB9906721D0 (en
GB2333176B (en
Inventor
Dallas W Meyer
Subrahmanyan Nagarajan
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Seagate Technology LLC
Original Assignee
Seagate Technology LLC
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
Priority claimed from US08/793,327 external-priority patent/US5999360A/en
Application filed by Seagate Technology LLC filed Critical Seagate Technology LLC
Publication of GB9906721D0 publication Critical patent/GB9906721D0/en
Publication of GB2333176A publication Critical patent/GB2333176A/en
Application granted granted Critical
Publication of GB2333176B publication Critical patent/GB2333176B/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

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
    • G11B5/012—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
    • G11B5/5521—Track change, selection or acquisition by displacement of the head across disk tracks
    • G11B5/5526—Control therefor; circuits, track configurations or relative disposition of servo-information transducers and servo-information tracks for control thereof
    • 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
    • G11B5/58—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 for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
    • G11B5/596—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 for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following on disks
    • G11B5/59627—Aligning for runout, eccentricity or offset compensation
    • 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
    • G11B5/58—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 for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
    • G11B5/596—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 for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following on disks
    • G11B5/59633—Servo formatting
    • 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
    • G11B5/58—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 for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
    • G11B5/596—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 for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following on disks
    • G11B5/59683—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 for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following on disks for magnetoresistive heads
    • 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
    • G11B5/74—Record carriers characterised by the form, e.g. sheet shaped to wrap around a drum
    • G11B5/82—Disk carriers
    • 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
    • G11B2005/0002—Special dispositions or recording techniques
    • G11B2005/0005—Arrangements, methods or circuits
    • G11B2005/0021—Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal

Landscapes

  • Magnetic Heads (AREA)
  • Moving Of The Head To Find And Align With The Track (AREA)

Abstract

A magnetic disc drive has a magnetoresistive element (26) for reading user data from concentric tracks of a rotatable magnetic recording disc (32). The magnetoresistive element has a resistance based on a magnetic field derived from user data and based on temperature of the magnetoresistive element. Heat generated by the bias current through the head is in part dissipated through the disc, the amount of heat dissipated being representative of disc/head spacing. The surface of the recording disc has contour elements (50, 52, 54) arranged in a pattern representing servo data, the contour elements having a height such that the spacing between the magnetoresistive element and the contour elements is different from the spacing between the magnetoresistive element and a nominal surface of the recording disc. As a result, a modulated signal (66) from the head contains a component representative of user data and a component representative of servo data.
GB9906721A 1996-10-15 1997-10-10 Disc drive servo system employing thermal signals Expired - Fee Related GB2333176B (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US2837196P 1996-10-15 1996-10-15
US08/793,327 US5999360A (en) 1996-10-15 1997-03-14 Disc drive servo system employing thermal signals
PCT/US1997/018325 WO1998016922A1 (en) 1996-10-15 1997-10-10 Disc drive servo system employing thermal signals

Publications (3)

Publication Number Publication Date
GB9906721D0 GB9906721D0 (en) 1999-05-19
GB2333176A true GB2333176A (en) 1999-07-14
GB2333176B GB2333176B (en) 2000-12-20

Family

ID=26703615

Family Applications (1)

Application Number Title Priority Date Filing Date
GB9906721A Expired - Fee Related GB2333176B (en) 1996-10-15 1997-10-10 Disc drive servo system employing thermal signals

Country Status (5)

Country Link
JP (1) JP2001524244A (en)
DE (1) DE19782063T1 (en)
GB (1) GB2333176B (en)
HK (1) HK1021241A1 (en)
WO (1) WO1998016922A1 (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8665549B2 (en) 2011-09-29 2014-03-04 HGST Netherlands B.V. Method for creating burst magnitude servo patterns with unipolar bits on a magnetic media of a magnetic data recording system

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5527110A (en) * 1993-04-30 1996-06-18 International Business Machines Corporation Method and apparatus for detecting asperities on magnetic disks using thermal proximity imaging

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02232803A (en) * 1989-03-06 1990-09-14 Nec Corp Magnetic head

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5527110A (en) * 1993-04-30 1996-06-18 International Business Machines Corporation Method and apparatus for detecting asperities on magnetic disks using thermal proximity imaging

Also Published As

Publication number Publication date
WO1998016922A1 (en) 1998-04-23
HK1021241A1 (en) 2000-06-02
GB9906721D0 (en) 1999-05-19
DE19782063T1 (en) 1999-10-14
JP2001524244A (en) 2001-11-27
GB2333176B (en) 2000-12-20

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Legal Events

Date Code Title Description
732E Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977)
711B Application made for correction of error (sect. 117/77)
711G Correction allowed (sect. 117/1977)
PCNP Patent ceased through non-payment of renewal fee

Effective date: 20041010