WO1984004990A1 - Systeme et procede d'organisation et d'exploitation des donnees stockees sur un disque a informations - Google Patents

Systeme et procede d'organisation et d'exploitation des donnees stockees sur un disque a informations Download PDF

Info

Publication number
WO1984004990A1
WO1984004990A1 PCT/US1984/000817 US8400817W WO8404990A1 WO 1984004990 A1 WO1984004990 A1 WO 1984004990A1 US 8400817 W US8400817 W US 8400817W WO 8404990 A1 WO8404990 A1 WO 8404990A1
Authority
WO
WIPO (PCT)
Prior art keywords
data
disk
band
bands
tracks
Prior art date
Application number
PCT/US1984/000817
Other languages
English (en)
Inventor
Juan A Rodriguez
A Kenneth Johnson
John W Mcintosh
James Kent Harness
Hadley Stacey
John Rundell
Frederick Ii Parham
Original Assignee
Storage Technology Partners
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 Storage Technology Partners filed Critical Storage Technology Partners
Publication of WO1984004990A1 publication Critical patent/WO1984004990A1/fr

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
    • G11B27/10—Indexing; Addressing; Timing or synchronising; Measuring tape travel
    • G11B27/19—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier
    • G11B27/28—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier by using information signals recorded by the same method as the main recording
    • G11B27/32—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier by using information signals recorded by the same method as the main recording on separate auxiliary tracks of the same or an auxiliary record carrier
    • 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
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
    • G11B27/10—Indexing; Addressing; Timing or synchronising; Measuring tape travel
    • G11B27/102—Programmed access in sequence to addressed parts of tracks of operating record carriers
    • G11B27/105—Programmed access in sequence to addressed parts of tracks of operating record carriers of operating discs
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
    • G11B27/10—Indexing; Addressing; Timing or synchronising; Measuring tape travel
    • G11B27/19—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier
    • G11B27/28—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier by using information signals recorded by the same method as the main recording
    • G11B27/32—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier by using information signals recorded by the same method as the main recording on separate auxiliary tracks of the same or an auxiliary record carrier
    • G11B27/322—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier by using information signals recorded by the same method as the main recording on separate auxiliary tracks of the same or an auxiliary record carrier used signal is digitally coded
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B27/00—Editing; Indexing; Addressing; Timing or synchronising; Monitoring; Measuring tape travel
    • G11B27/10—Indexing; Addressing; Timing or synchronising; Measuring tape travel
    • G11B27/19—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier
    • G11B27/28—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier by using information signals recorded by the same method as the main recording
    • G11B27/32—Indexing; Addressing; Timing or synchronising; Measuring tape travel by using information detectable on the record carrier by using information signals recorded by the same method as the main recording on separate auxiliary tracks of the same or an auxiliary record carrier
    • G11B27/327—Table of contents
    • G11B27/329—Table of contents on a disc [VTOC]
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/004—Recording, reproducing or erasing methods; Read, write or erase circuits therefor
    • G11B7/005—Reproducing
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/007—Arrangement of the information on the record carrier, e.g. form of tracks, actual track shape, e.g. wobbled, or cross-section, e.g. v-shaped; Sequential information structures, e.g. sectoring or header formats within a track
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
    • G11B7/085—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam into, or out of, its operative position or across tracks, otherwise than during the transducing operation, e.g. for adjustment or preliminary positioning or track change or selection
    • G11B7/08505—Methods for track change, selection or preliminary positioning by moving the head
    • 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
    • G11B20/1258—Formatting, e.g. arrangement of data block or words on the record carriers on discs where blocks are arranged within multiple radial zones, e.g. Zone Bit Recording or Constant Density Recording discs, MCAV discs, MCLV discs

Definitions

  • This invention relates to data storage systems wherein information is stored on a rotating disk, and more particularly to a system and method for organizing and managing the data stored on an informational disk.
  • a direct access storage system selectively positions a read/write head along a radial axis of a rotating disk. As the disk rotates, the read/write head may thereby directly access any segment of a given data track on the disk by merely waiting until the desired segment of the track rotates under the head.
  • sequential storage systems typically use a long tape, usually wound on reels or spools, that is driven past a stationary read/write head at a desired speed. Information stored at one end of the tape can only be accessed by sequentially moving the entire tape past the read/write head until the desired portion of the tape is next to the head.
  • an optical disk storage system has the inherent direct access characteristics of a magnetic disk system in that any given track can, at least in theory, be accessed by merely radially moving the read/write head until the desired track is located.
  • the actual time required to locate and access a given track could, if conventional accessing and formatting techniques are used, take longer than the access time that has heretofore been achievable with magnetic disk systems.
  • the large storage capacity of optical disk systems lends itself nicely to a sequential access storage system wherein extremely long sequential files can be stored.
  • indexing that is, keeping track of where identified information is stored on the disk. If traditional indexing methods are used -- wherein one index entry is made for every 4-6 Kbytes of data -- the size of the index itself may become extremely large, especially for the large data files or records that could be stored on an optical disk.
  • Still another object of the invention is to provide such informational disk format that may be easily used with both small and very large data records.
  • a further object of the invention is to provide an informational disk for use on a disk storage system wherein indexing information is easily stored on the disk without requiring a large amount of disk storage space.
  • Still a further object of the invention is to provide a method for managing the information stored on an informational disk that is flexible and adaptable for use with a wide variety of storage applications.
  • a band of data advantageously represents the unit that can be physically addressed and accessed by the radial arm upon which is found the read/write head.
  • a data band represents the unit that can be logically addressed to access a given file or record.
  • the optical disk drive hardware is able to selectively search for a given data band at very high speeds.
  • the data band is also the element that can be indexed.
  • One data band on each disk is maintained as an index band.
  • the contents of the index band may be loaded into a memory device, such as a random access memory (RAM).
  • RAM random access memory
  • the drive determines the data band where the desired file is located by looking in the RAM, and. then initiates a high speed search to the identified band.
  • Each data band comprises a large number of data tracks.
  • One data track in each band is pre-written on the disk as an address track that is used to uniquely identify the data band.
  • the other data tracks may be written with variable length data files.
  • a lengthy data file (normally accessed sequentially) may be written in a given data band, or smaller data files (normally accessed directly) may also be written in a desired band.
  • the data in a given data band may be accessed with almost equal speed.
  • adjacent data bands on the disk are separated by coarse servo tracks, which servo tracks are typically 3-5 times the width of the data tracks. These coarse servo tracks are used by a coarse servo system of the disk drive to position and maintain the read/write head of the disk drive over a desired band. Access to a desired track within a selected band is achieved by a fine servo system.
  • FIG. 1 is a block diagram of a coarse/fine servo system used in an optical disk data storage system, and illustrates the preferred environment in which the invention could be used;
  • FIG. 2 schematically shows the principle elements of FIG. 1;
  • FIG. 3 is a side view of an optical disk drive and schematically shows the relationship between the optical disk, fixed and moving optics packages, and a linear actuator for controllably positioning the read/write head;
  • FIG. 4 is an expanded view of a segment of the optical disk surface and further illustrates the data bands separated by coarse servo tracks;
  • FIG. 5 is an expanded view of a portion of a data band, and illustrates a representative organization thereof.
  • FIG. 1 shows a block diagram of a coarse/fine servo system of a type with which the present invention could be used.
  • the various optical paths associated with the system shown in FIG. 1 are illustrated as bold lines, whereas electrical paths are indicated by fine lines.
  • Mechanical coupling, as occurs between a carriage actuator 24 and the carriage optics 23, is indicated by a dashed line.
  • the optical drive system of the preferred embodiment allows reading and writing from and to the surface of a disk 11 having a rotational axis 10 and a plurality of concentric data bands 12-14 (shown in FIG. 2).
  • Each of the data bands includes space on the surface of the disk where a plurality of data tracks could be concentrically written about the rotational axis.
  • the surface of the disk 11 has pre-recorded thereon, during manufacture, a plurality of optically readable servo tracks 16-19, concentrically and uniformly spaced about the rotational axis of the disk and positioned between the data bands.
  • One data track, preferably adjacent to a servo track is pre-written during manufacture with an address that uniquely identifies the data band where the address track is located.
  • the disk 11 is rotated about its axis 10 by conventional means.
  • An optical read/write head depicted by the carriage optics block 23, is positioned adjacent to the surface of the disk 11.
  • Carriage actuator 24 selectively moves the read/write head along a radial axis 20 (FIG. 2), thereby moving the carriage optics 23 in a radial direction with respect to the disk 11 in order to access the data bands thereon.
  • Mechanical motion of the carriage optics 23 is depicted in FIG. 2 as a dotted line 45, with motion being possible in both directions as indicated by the double headed arrow 45'.
  • a fine read/write servo illuminator and detector 25 projects read or write light beam(s) 52' to the surface of the disk 11 so as to access data tracks thereon.
  • this beam 52' is reflected by a fine tracking mirror 26, passes through a beam combiner and separator 27, as well as through the carriage optics 23.
  • a read detector 25b (FIG. 1) that reads light which has been reflected from the accessed recorded data track. This reflected light passes through the carriage optics 23 and beam combiner and separator 27 before reaching the read detector 25b.
  • the read detector converts this light to an equivalent electrical signal(s). This read electrical signal is, in turn, supplied to a data read system 25c, and to a fine access/tracking servo system 25d.
  • the servo system for access to and tracking of the coarse servo tracks includes a coarse illuminator 30 which projects light, represented as dashed double-dot lines in FIG. 2, through a coarse servo beam separator 36, a beam combiner and separator 27, and the carriage optics 23 onto a relatively broad portion 11a of the disk surface (FIG. 2).
  • An optical detector 31 detects reflected light, represented as dashed single-dot lines in FIG. 2, from the portion 11a of the disk surface. It is noted that the illuminated portion 11a of the disk surface spans at least the distance between two coarse servo tracks, and thereby always illuminates at least one coarse servo track. As shown in FIG. 2, light is reflected from the portion 11a of the disk 11 between servo tracks 16 and 18 with the servo track 17 being projected onto a coarse detector 31.
  • the output of the coarse detector circuitry 31 is a coarse track position error signal (PES), which signal has an amplitude proportional to the location at which the reflected radiation from the illuminated coarse servo track falls on the face of the detector 31.
  • PES coarse track position error signal
  • This error signal from the detector 31 is applied to a coarse access/tracking system 34.
  • This system is connected in a servo loop with the actuator 24, which actuator moves the read/write head (represented schematically by the carriage optics 23) into radial proximity of a selected servo track so that the fine access and tracking system 25d can accurately position read or write beams on a selected data track.
  • the carriage optics 23, beam separator 27, and tracking mirror 26 As indicated previously, light reflected from a single data track on the disk is passed by means of the carriage optics 23, beam separator 27, and tracking mirror 26, and is detected by read detector 25b, the output of which is applied to the fine access/tracking servo system 25d.
  • the read or write beams 52' from the illuminator 25a are moved radially with respect to the optical disk 11 by means of the tracking mirror 26, thereby providing for fine selective control of the beam's radial position.
  • the tracking mirror 26, which may be a conventional galvanometer controlled mirror(s), is controlled by the fine access/tracking servo system 25d.
  • the servo tracks In order to discriminate radiation reflected from servo tracks from that reflected from data tracks or other areas of the disk surface, the servo tracks preferably have an on/off (reflectivity-high/reflectivity-low) pattern placed therein that may be conceptually thought of as a dashed line, as shown best in FIG. 4. Further, the servo tracks are preferably three- to five times the width of the data tracks.
  • the servo tracks provide improved data track following capability by providing coarse tracking control of the read/write head.
  • the coarse tracks are also used to permit rapid random access to a desired data band, regardless of whether any data has been recorded in the fine track area. This provides the ability to skip to randomly selected data bands for reading or writing. Seeking to a selected band may be accomplished by counting coarse tracks, or by any other suitable track seeking technique commonly used in magnetic disk drives.
  • FIG. 3 is a side view that schematically shows the relationship between the optical disk 11 and a moving optics package 40 that is driven by the carriage actuator 24 into a read/write relationship with any of the tracks on the disk 11.
  • the carriage actuator 24 may be realized with a linear motor, such as a voice coil motor, that includes a stationary magnet 41 and a moveable coil 49.
  • the optical path for either the read or write light beam(s) to the surface of the disk 11 includes an objective lens 50, mirror 42, telescope lens 43, and mirror 44.
  • Light is transmitted to and from the moving optics package 40 through a suitable optics package 47 mounted to a fixed optic plate 48 on which the remainder of the optics are mounted.
  • the details associated with this optics package are not pertinent to the present invention. Any suitable technique could be used within the optics package to achieve the desired reading and writing capabilities.
  • FIG. 4 further details the concept of a data band that is used in formatting an optical disk in accordance with the present invention.
  • Data bands are placed concentrically about the center of the disk and are separated by coarse servo tracks 16-18. There may be over 700 data bands on a single optical disk, and each data band may have approximately 50-60 data tracks associated therewith. Each data track may, in turn, have a storage capacity of around 118 Kbytes.
  • One data band per disk is set aside as an index band 60. Indexing information is written into this band to identify the types of files or records, and/or the contents thereof that are written in the other optical data bands on that same disk. (For purposes of this application, the terms "data file” and "data record” are used synonymously to indicate a collection of data bytes that is stored as a group.)
  • FIG. 5 is a representative expanded view of how a given data band could be organized.
  • the organization of FIG. 5 is given by way of example only, and is given to illustrate the flexibility that exists through use of the data band concept.
  • the servo track 17 separates the data band 13 from an adjacent data band 12.
  • a first data track within the data band 13 is an address track 62.
  • This address track has information written thereon, during manufacture of the disk, that uniquely identifies the data band 13.
  • the rapid seek servo would typically count servo tracks to get to what the servo believes is the desired band. However, once there, the address track would be
  • a first data file or record 64 within the data band 13 of FIG. 5 may comprise 4 data tracks.
  • a second data file 66 may comprise only a portion of another data track; while a third data file 68 may comprise another portion of this same data track 72.
  • a fourth data file 70 may comprise two data tracks.
  • a fifth data file 72 may comprise a large number of data tracks, e.g., the balance of the data tracks remaining in the band.
  • an important feature of the present invention is allowing data files or data records to be variable in length. Thus, large data records, such as are common in sequential access storage applications, may be stored on the disk; as may smaller data files or records, as are common in direct access storage applications.
  • an indexing band 60 (FIG. 4) is placed on the disk itself.
  • the contents of the indexing band may be advantageously loaded into a RAM, or other suitable memory element. Locating a band wherein a desired data record is stored can then be quickly done at electronic signal processing speeds by electronically scanning the contents of the memory device. The identified band can then be rapidly accessed through a high speed search (seek) operation of the coarse servo system. Response times using such an approach, measured from the time the request is made until the desired data is retrieved, are very competitive with comparable data retrieval operations performed by magnetic disk drives.
  • the present invention is not limited to a particular type of optical disk media, or coding scheme used to record the data on the media.
  • any type of marking mechanism could be used to mark the data on the media; and it matters little whether the media exhibits high or low reflectivity at a desired mark, so long as sufficient contrast exists between marks and non-marks so that data can be properly distinguished and read by whatever optical read mechanism and/or encoding scheme is employed.
  • any type of disk or disk data storage system could employ the present invention; although, as a practical matter, the invention is best suited for use with storage media having very large storage capacities, such as are achieved with optical disk media used with optical storage devices.
  • disk formatting and management scheme of the present invention is not limited to removable media. However, again as a practical matter, it is disk storage systems employing removable media having large storage capacities for which the invention is best suited.
  • data bands including a data band that functions as an index band, and means for uniquely identifying each data band, allows great flexibility in configuring different systems for different applications. That is, the present invention could be easily used with storage systems coupled to a single central processing unit (CPU), or to multiple CPU's. Further, the invention is especially versatile for use in a system wherein removable media can be automatically and selectively retrieved by the drive mechanism, such as in a juke-box type system.
  • CPU central processing unit

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Optical Recording Or Reproduction (AREA)

Abstract

Système et procédé d'organisation des données contenues par un disque optique amovible. La zone de surface du disque est divisée en des bandes de données concentriques (12, 13, 14), comprenant chacune une zone de surface de disque suffisante pour l'écriture d'un grand nombre de pistes concentriques de données. Des pistes d'asservissement concentriques (16, 17, 18), plus larges que les pistes de données, sont utilisées pour séparer des bandes de données adjacentes. Chaque bande de données utilise une piste de données (62) comme piste d'adresse sur laquelle sont écrites au préalable les données identifiant cette bande de données particulière. Une bande de données (60) est réservée comme bande d'index sur laquelle peuvent être écrites des informations d'indexage, identifiant quelles données sont écrites dans chaque bande. On peut accéder rapidement à un fichier ou enregistrement de données désiré en utilisant la bande d'index pour identifier l'adresse de la bande où sont situées les donnés désirées, de manière à avoir accès directement et rapidement à la bande identifiée.
PCT/US1984/000817 1983-06-07 1984-05-25 Systeme et procede d'organisation et d'exploitation des donnees stockees sur un disque a informations WO1984004990A1 (fr)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US50195683A 1983-06-07 1983-06-07

Publications (1)

Publication Number Publication Date
WO1984004990A1 true WO1984004990A1 (fr) 1984-12-20

Family

ID=23995718

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1984/000817 WO1984004990A1 (fr) 1983-06-07 1984-05-25 Systeme et procede d'organisation et d'exploitation des donnees stockees sur un disque a informations

Country Status (2)

Country Link
EP (1) EP0145751A1 (fr)
WO (1) WO1984004990A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0164061A1 (fr) * 1984-06-01 1985-12-11 Matsushita Electric Industrial Co., Ltd. Disque optique exclusivement de reproduction
WO1987003129A1 (fr) * 1985-11-14 1987-05-21 Eastman Kodak Company Enregistreur a debit binaire variable
GB2221563A (en) * 1985-04-05 1990-02-07 Canon Kk Method of detecting the position of an optical head
EP0542730A2 (fr) * 1986-02-07 1993-05-19 Matsushita Electric Industrial Co., Ltd. Disque optique et appareil à disques pour enregistrer ou reproduire des données sur le ou à partir du disque

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4094013A (en) * 1975-05-22 1978-06-06 U.S. Philips Corporation Optical storage disk system with disk track guide sectors
US4106058A (en) * 1976-04-23 1978-08-08 Thomson-Brandt Data disc optical reader containing a device for automatic data access
US4138741A (en) * 1976-03-19 1979-02-06 Rca Corporation Disc eccentricity compensating system
US4229808A (en) * 1978-12-21 1980-10-21 Ncr Corporation Method for recording multiple data segments on a storage disc with eccentricity factor
US4283777A (en) * 1979-05-14 1981-08-11 Xerox Corporation Optical memory having a parallel read out
US4290122A (en) * 1979-05-14 1981-09-15 Xerox Corporation Self-synchronizing clock source for optical memories
US4363116A (en) * 1978-03-16 1982-12-07 U.S. Philips Corporation Method, apparatus and record carrier body for optically writing information
US4451915A (en) * 1982-04-15 1984-05-29 Burroughs Corporation Optical storage system employing a multi-layer optical medium

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4094013A (en) * 1975-05-22 1978-06-06 U.S. Philips Corporation Optical storage disk system with disk track guide sectors
US4138741A (en) * 1976-03-19 1979-02-06 Rca Corporation Disc eccentricity compensating system
US4106058A (en) * 1976-04-23 1978-08-08 Thomson-Brandt Data disc optical reader containing a device for automatic data access
US4363116A (en) * 1978-03-16 1982-12-07 U.S. Philips Corporation Method, apparatus and record carrier body for optically writing information
US4229808A (en) * 1978-12-21 1980-10-21 Ncr Corporation Method for recording multiple data segments on a storage disc with eccentricity factor
US4283777A (en) * 1979-05-14 1981-08-11 Xerox Corporation Optical memory having a parallel read out
US4290122A (en) * 1979-05-14 1981-09-15 Xerox Corporation Self-synchronizing clock source for optical memories
US4451915A (en) * 1982-04-15 1984-05-29 Burroughs Corporation Optical storage system employing a multi-layer optical medium

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0164061A1 (fr) * 1984-06-01 1985-12-11 Matsushita Electric Industrial Co., Ltd. Disque optique exclusivement de reproduction
GB2221563A (en) * 1985-04-05 1990-02-07 Canon Kk Method of detecting the position of an optical head
GB2221563B (en) * 1985-04-05 1990-06-20 Canon Kk Optical head
WO1987003129A1 (fr) * 1985-11-14 1987-05-21 Eastman Kodak Company Enregistreur a debit binaire variable
US4714967A (en) * 1985-11-14 1987-12-22 Eastman Kodak Company Binarily related variable rate recorder
EP0542730A2 (fr) * 1986-02-07 1993-05-19 Matsushita Electric Industrial Co., Ltd. Disque optique et appareil à disques pour enregistrer ou reproduire des données sur le ou à partir du disque
EP0542730A3 (en) * 1986-02-07 1993-08-25 Matsushita Electric Industrial Co., Ltd. Optical disc and disc drive apparatus for writing/reading data into/from the disc

Also Published As

Publication number Publication date
EP0145751A1 (fr) 1985-06-26

Similar Documents

Publication Publication Date Title
US4566087A (en) Digital optical disk system
KR950014668B1 (ko) 데이타 기록 및 탐색 방법, 데이타 기억 및 액세스 방법, 데이타 기록 및 판독 방법, 데이타 판독 및 기록 시스템 및 일회 기록 다회 판독(worm) 데이타 기억 매체
US4229808A (en) Method for recording multiple data segments on a storage disc with eccentricity factor
EP0328240B1 (fr) Exploitation de l'espace de mémorisation de données sur des supports d'enregistrement à grande capacité
EP0745255B1 (fr) Support d'enregistrement multicouche et appareil de lecture de celui-ci
EP0164061A1 (fr) Disque optique exclusivement de reproduction
US6937411B2 (en) Method, system, program, and storage cartridge for storing data in a storage medium
EP0360123A2 (fr) Unité de stockage de données à très grande capacité
GB2058431A (en) Positioning system and formatting scheme for magnetic tape media
RU2131625C1 (ru) Запоминающее устройство прямого доступа с магниторезистивной преобразующей головкой
US4398228A (en) Method of avoiding resonance in servo controlled apparatus
WO1984004990A1 (fr) Systeme et procede d'organisation et d'exploitation des donnees stockees sur un disque a informations
US5280468A (en) Optical recording medium
US5822283A (en) Method for enhancing data access of CD-ROM changer
JP2670132B2 (ja) 光カード記録再生装置
US6798602B2 (en) Window based directory for magnetic tape
JPH04170765A (ja) データ記録方法
KR910006654B1 (ko) 대기억 용량을 갖는 데이타 기억용 기록 매체 및 방법
JPS62270026A (ja) カ−ド状光情報記録媒体およびその光情報記録再生装置
CA1242273A (fr) Disque optique a pistes d'asservissement formatees
JPH07114443A (ja) ファイル検索方法及び磁気テープ装置
JP2601615B2 (ja) 情報記録方法
JPS63298869A (ja) 記録再生装置
JPS645392B2 (fr)
JP2698420B2 (ja) カード状記録媒体のアクセス方法

Legal Events

Date Code Title Description
AK Designated states

Designated state(s): JP NL

AL Designated countries for regional patents

Designated state(s): FR NL