WO1995005659A1 - Systeme de detection du defaut d'alignement d'un disque - Google Patents

Systeme de detection du defaut d'alignement d'un disque Download PDF

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Publication number
WO1995005659A1
WO1995005659A1 PCT/US1994/009260 US9409260W WO9505659A1 WO 1995005659 A1 WO1995005659 A1 WO 1995005659A1 US 9409260 W US9409260 W US 9409260W WO 9505659 A1 WO9505659 A1 WO 9505659A1
Authority
WO
WIPO (PCT)
Prior art keywords
disk
recording head
rotating disk
signal
track position
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.)
Ceased
Application number
PCT/US1994/009260
Other languages
English (en)
Inventor
Kevin Mcdonnell
James S. Dickerson
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.)
Trace Mountain Products Inc
Original Assignee
Trace Mountain Products Inc
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 Trace Mountain Products Inc filed Critical Trace Mountain Products Inc
Publication of WO1995005659A1 publication Critical patent/WO1995005659A1/fr
Anticipated expiration legal-status Critical
Ceased 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
    • G11B5/48—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
    • G11B5/553—Details
    • G11B5/5534—Initialisation, calibration, e.g. cylinder "set-up"

Definitions

  • the invention relates to electronic storage systems, particularly to disk duplication or recording systems.
  • digital data are commonly stored in electronic media, such as magnetic or optical disks.
  • a mechanical drive subsystem and a read/write head coupled thereto cooperate to store and retrieve data to and from the disk.
  • digital signals may be written to or read from certain locations on the disk surface by the head.
  • the disk To ensure proper signal recording, the disk must be positioned in the disk drive such that the center of the disk is aligned axially to rotate about the drive axis of disk drive.
  • the step of seating the disk properly in the disk drive is referred to as "chucking.”
  • chucking Sometimes when the disk rotates out of alignment, or “mis-chucks, " improper signal recording results. It would be desirable, therefore, to provide a technique for detecting disk mis-chucking.
  • the invention resides in a magnetic or optical disk duplication or recording system having a disk drive and a recording head, wherein axial mis-alignment or chucking failure of a disk positioned to rotate about a disk drive axis is detected.
  • a first digital data signal is written by the recording head to tracks on the rotating disk, the head being positioned at an initial track position.
  • a first duration is pre-specified, between, when the recording head detects an index provided on the rotating disk and when the recording head detects a mark or pattern thereon.
  • the disk is removed and re-inserted in the same disk drive, and then the recording head is re-positioned at the initial track position.
  • a second digital data signal is then read from the initial track position, and a second duration is determined, between when the recording head detects the index and the pattern from the disk. Disk chucking failure is detected when the first and second durations, and/or the first and second digital data signals, are determined to be substantially different.
  • FIG. 1 is a generalized block diagram of disk duplication or recording system 10.
  • FIG. 2 is a simplified flow chart of a process for detecting disk chucking failure, per the present invention.
  • FIG. 1 is a simplified diagram of disk duplication or recording system 10 for storing (writing) or retrieving (reading) digital data in the form of electronic signals in magnetic or optical media or disks 24.
  • System 10 includes controller 12, which preferably includes microprocessor 14 and digital memory 16, disk drive assembly 38, and recording head mechanism 20.
  • system 10 When operating normally, system 10 receives 22 diskette or disk 24 which is inserted into disk drive 38, wherein digital data may be read from or written to disk 24.
  • disk 24 may be mounted or "chucked” on a rotating fixture and thereby caused to rotate about rotational axis 28..
  • recording head 20 is positioned to read or write digital data signals to or from various storage locations on the disk surface, which is typically partitioned into pre-defined regions called sectors or tracks .
  • processor 14 in controller 12 may cause 18 recording head mechanism 20 to store and retrieve digital data from the pre-defined sectors and tracks on disk 24.
  • Disk chucking failure arises, and proper data recording is thereby prevented. Disk chucking failure may arise either initially during disk 24 placement or subsequently during disk drive 38 operation.
  • a disk chucking failure technique is applied to disk duplication or recording system 10, as illustrated generally in the flow chart of FIG. 2.
  • disk 24, 26 is inserted 22 for seating or chucking into disk drive 38.
  • disk processing 52 and disk chucking failure detection 58 steps are performed under control of procesor 14 in controller 12.
  • disk drive 38 causes inserted disk 24 (chucked) , 26 (mis-chucked) to rotate conventionally about rotational axis 28, assuming disk 24, 26 is chucked successfully.
  • disk . insertion step 50 may be repeated, prior to disk chucking failure detection step 58.
  • disk 24, 26 may be removed from disk drive 38, and then re ⁇ inserted 50, 22 shortly thereafter for seating or chucking in the same disk drive 38.
  • disk 24, 26, if previously mis-chucked, is likely to be re-chucked properly, or at least differently, thereby facilitating disk re ⁇ placement comparison for chucking failure detection, in accordance with the present invention.
  • controller 12 causes inserted disk 24, 26 to be initialized or formatted by recording head mechanism 20, for example, according to pre- specified, conventional sectors and tracks.
  • controller 12 causes a first digital data signal, including an identifiable binary pattern or data signature, to be written 56 by recording head 20 to certain storage locations on disk 24, 26.
  • recording head 20 is positioned radially from center axis 28 at an initial, user-specified track position (N) , such that first digital data signal may be written to disk 24, 26 beginning at a first concentric track (N) 32 corresponding to the initial track position of recording head 20.
  • Disk chucking failure detection 58 occurs after recording or duplication data are written 56 on various tracks (N, N+l, N+2, etc.) of disk 24, 26. Controller 12 first causes recording head 20 to return or be re-positioned 60 for reading (or writing) initially at the same, initial track (N) position. Then, a second, previously-written digital data signal is read by recording head 20 from disk 24, 26, when positioned at the initial track position.
  • Controller 12 calculates or determines a second duration, which is the time delay or temporal difference between when recording head 20 detects or senses index 34,
  • disk chucking failure detection 58 occurs generally when the first and second durations, and/or the first and second digital data signals, are determined to be substantially different. This determination may arise, for example, as a result of disk 24 being shifted laterally to off-center position of disk 26.
  • axial mis-alignment of disk 26 is indicated by controller 12 when there has been a substantial change in index-to-mark time 62, before and after data duplication or recording, or when data signals or content written in initial track (N) and read 64 therefrom after subsequent data duplication or recording, are compared and determined to be substantially different.
  • Either checking step 62, 64 may be performed by controller 12, in any sequence, to detect disk chucking failure.
  • substantial change which is indicative of disk chucking failure arises when the difference in compared data signals or index-to-mark times exceeds a user- specified tolerance; for example, 26 microseconds for index- to-mark time.
  • a user- specified tolerance for example, 26 microseconds for index- to-mark time.

Landscapes

  • Indexing, Searching, Synchronizing, And The Amount Of Synchronization Travel Of Record Carriers (AREA)

Abstract

On détecte le défaut d'alignement axial d'un disque monté pour tourner autour de l'axe d'une unité de disques dans un système magnétique ou optique de reproduction et d'enregistrement de disques (10) comportant une unité de disques et une tête d'enregistrement (20). Un signal de données numériques est enregistré par la tête d'enregistrement sur des pistes situées sur le disque en rotation (24), la tête étant positionnée initialement au niveau d'une certaine position de piste. On détermine la durée entre le moment où la tête d'enregistrement (20) détecte un point d'indexage situé sur le disque en rotation et le moment où la tête d'enregistrement détecte un repère sur le disque. De préférence après le retrait et la réinsertion du disque dans la même unité de disques, la tête d'enregistrement (20) est repositionnée à la position initiale de piste, de façon à pouvoir lire un autre signal de données numériques au niveau de ladite position initiale. On détermine une autre durée entre les moments où la tête d'enregistrement détecte le point d'indexage et le repère sur le disque. Le défaut d'alignement du disque est détecté quand les durées ainsi que les signaux de données numériques sont sensiblement différents.
PCT/US1994/009260 1993-08-17 1994-08-16 Systeme de detection du defaut d'alignement d'un disque Ceased WO1995005659A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US10793793A 1993-08-17 1993-08-17
US08/107,937 1993-08-17

Publications (1)

Publication Number Publication Date
WO1995005659A1 true WO1995005659A1 (fr) 1995-02-23

Family

ID=22319286

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1994/009260 Ceased WO1995005659A1 (fr) 1993-08-17 1994-08-16 Systeme de detection du defaut d'alignement d'un disque

Country Status (1)

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WO (1) WO1995005659A1 (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4149199A (en) * 1976-07-06 1979-04-10 Data Recording Instrument Company Ltd. Magnetic disc storage device with track centering correction
US4513331A (en) * 1982-10-12 1985-04-23 Dysan Corporation Method and apparatus for disk drive alignment
US5068754A (en) * 1989-11-22 1991-11-26 Seagate Technology, Inc. Method and apparatus for measuring bit shift

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4149199A (en) * 1976-07-06 1979-04-10 Data Recording Instrument Company Ltd. Magnetic disc storage device with track centering correction
US4513331A (en) * 1982-10-12 1985-04-23 Dysan Corporation Method and apparatus for disk drive alignment
US5068754A (en) * 1989-11-22 1991-11-26 Seagate Technology, Inc. Method and apparatus for measuring bit shift

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