WO2001043122B1 - Magnetic disc having physical servo patterns with a magnetic carrier, and method of making and using the same - Google Patents

Magnetic disc having physical servo patterns with a magnetic carrier, and method of making and using the same

Info

Publication number
WO2001043122B1
WO2001043122B1 PCT/US2000/042493 US0042493W WO0143122B1 WO 2001043122 B1 WO2001043122 B1 WO 2001043122B1 US 0042493 W US0042493 W US 0042493W WO 0143122 B1 WO0143122 B1 WO 0143122B1
Authority
WO
WIPO (PCT)
Prior art keywords
magnetic
servo
pattern
disc
irregularities
Prior art date
Application number
PCT/US2000/042493
Other languages
French (fr)
Other versions
WO2001043122A3 (en
WO2001043122A2 (en
Inventor
Alexei H Sacks
Timothy F Ellis
Patrick J Korkowski
Karl A Belser
Original Assignee
Seagate Technology Llc
Alexei H Sacks
Timothy F Ellis
Patrick J Korkowski
Karl A Belser
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 Seagate Technology Llc, Alexei H Sacks, Timothy F Ellis, Patrick J Korkowski, Karl A Belser filed Critical Seagate Technology Llc
Priority to US09/726,786 priority Critical patent/US6510015B2/en
Publication of WO2001043122A2 publication Critical patent/WO2001043122A2/en
Publication of WO2001043122A3 publication Critical patent/WO2001043122A3/en
Publication of WO2001043122B1 publication Critical patent/WO2001043122B1/en

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y10/00—Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
    • 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
    • G11B21/00—Head arrangements not specific to the method of recording or reproducing
    • G11B21/02—Driving or moving of heads
    • G11B21/022—Programmed access in sequence to indexed parts of operating record carriers
    • G11B21/025—Programmed access in sequence to indexed parts of operating record carriers of rotating 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
    • G11B5/48—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
    • G11B5/59655—Sector, sample or burst servo format
    • 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
    • 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
    • G11B5/743—Patterned record carriers, wherein the magnetic recording layer is patterned into magnetic isolated data islands, e.g. discrete tracks
    • 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

Abstract

A magnetic medium comprises a magnetic disc (106) having a read surface (228) that has a plurality of tracks (200), at least some having servo sectors (204). The servo sectors comprise a plurality of magnetic irregularities, such as pits (226) or regions (306) of reduced magnetic coercivity, arranged in a servo pattern along the servo sector at a servo frequency. A magnetic pattern is recorded in the disc along the servo sector (204) at a high carrier frequency. A process for manufacturing the servo pattern and for recovering servo data from the servo pattern are also described.

Claims

AMENDED CLAIMS[received by the International Bureau on 19 December 2001 ( 19 12 01), original claims 1 , 2. 6 and 7 amended, remaining claims unchanged (2 pages)]
1. A magnetic medium comprising a magnetic body defining a read surface havmg a plurality of tracks; and means extending along a length of a servo sector of at least one of the plurality of tracks defining a servo pattern representing servo data havmg a servo frequency.
2. The magnetic medium of claim 1, wherem the means defining a servo pattern comprises: a pattern of irregularities in magnetic properties of the magnetic body extending along the length of the servo sector, the pattern of irregularities representing servo data at the servo frequency, and a magnetic pattern recorded in the magnetic body along the length of the servo sector, the magnetic pattern having a carrier frequency greater than the servo frequency, the magnetic pattern forming regions adjacent the pattern of irregularities defining a predetermined ratio of magnetic strengths.
3. The magnetic medium of claim 2, wherein the magnetic body is a magnetic disc and the irregularities in magnetic properties comprises surface irregularities in a read surface of the disc.
4. The magnetic medium of claim 2, wherem the magnetic body is a magnetic disc and the irregularities in magnetic properties comprises discontinuities in magnetic coercivity in the magnetic disc.
5. The magnetic medium of claim 2, wherein the carrier frequency is at least twice the servo frequency.
6. A process of manufacturing a magnetic disc for use with a read head in a disc drive, the read head being designed to fly a predetermined height from a read surface of the disc to provide a readback signal having amplitudes based on magnetic fields generated from the disc, the process comprising steps of:
(a) defining a plurality of tracks on the read surface, each track having at least one data sector and at least one servo sector;
(b) forming a plurality of irregularities in magnetic properties of the magnetic disc in a pattern along each servo sector, the pattern having a servo frequency; and
(c) writing a magnetic carrier in the magnetic disc along the length of the servo sectors at a carrier frequency that is greater than the servo frequency, to form regions adjacent the irregularities defining a predetermined ration of magnetic strengths.
7. The process of claim 6, wherein step (b) comprises steps of: bl) forming surface irregularities in the discs having an elevation, h, different from the read surface such that
Figure imgf000004_0001
where λ is the wavelength of the magnetic carrier, Vi is a first readback signal peak amplitude provided by the read head confronting a surface irregularity and V2 is a second readback signal peak amplitude provided by the read head confronting the read surface.
STATEMENT UNDER ARTICLE 19
The principal reference, U.S. 3,593,331, describes a system of pits in a magnetic disc arranged so that pits of varying widths across the track are centered on the track and edge pits are along the edges of the track. The pits are used to sense the position of the transducing head relative to the track for head position control.
To more clearly distinguish claims from the reference, the claims are amended to recite that the magnetic pattern forms regions adjacent the irregularities m tne meαium to define a predetermined ratio of magnetic strengths and that the pattern represents servo data. These features clearly distinguish from U.S. 3,593,331 in that the pits m the reference do not represent servo data, and there is nothing in the reference to suggest a predetermined ratio of magnetic strengths.
PCT/US2000/042493 1999-12-10 2000-11-30 Magnetic disc having physical servo patterns with a magnetic carrier, and method of making and using the same WO2001043122A2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US09/726,786 US6510015B2 (en) 1999-12-10 2000-11-30 Magnetic disc having physical servo patterns with a magnetic carrier, and method of making and using the same

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US17023999P 1999-12-10 1999-12-10
US60/170,239 1999-12-10

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US09/726,786 Continuation US6510015B2 (en) 1999-12-10 2000-11-30 Magnetic disc having physical servo patterns with a magnetic carrier, and method of making and using the same

Publications (3)

Publication Number Publication Date
WO2001043122A2 WO2001043122A2 (en) 2001-06-14
WO2001043122A3 WO2001043122A3 (en) 2002-02-21
WO2001043122B1 true WO2001043122B1 (en) 2002-06-20

Family

ID=22619122

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2000/042493 WO2001043122A2 (en) 1999-12-10 2000-11-30 Magnetic disc having physical servo patterns with a magnetic carrier, and method of making and using the same

Country Status (2)

Country Link
US (1) US6510015B2 (en)
WO (1) WO2001043122A2 (en)

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US6510015B2 (en) 2003-01-21
US20010036030A1 (en) 2001-11-01
WO2001043122A3 (en) 2002-02-21
WO2001043122A2 (en) 2001-06-14

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