公开(公告)号：DE69027514D1

公开(公告)日：1996-07-25

申请号：DE69027514

申请日：1990-12-07

Applicant: IBM

Inventor： TAYEFEH MOROVAT

IPC: G01J4/04 ,  G01J1/44 ,  G11B7/005 ,  G11B11/10 ,  G11B11/105 ,  G11B7/13 ,  G11B7/00

Abstract: The present invention relates to an optical detection circuit comprising detecting means for detecting signals representing both polarisation modulation and intensity modulation in a received light beam. According to the invention the device is characterised in that the detecting means comprises polarisation modulation detection means (32, 33) for detecting two forms of polarisation, and conversion means (40) for selectively inhibiting the portion of the polarisation modulation detection means which detects one of the forms of polarisation so as to convert the polarisation modulation detection means into intensity modulation detection means when required.

公开(公告)号：CA2046705C

公开(公告)日：1995-09-26

申请号：CA2046705

申请日：1991-07-10

Applicant: IBM

Inventor： KULAKOWSKI JOHN EDWARD ,  MEANS RODNEY JEROME ,  TAYEFEH MOROVAT

IPC: G11B7/00 ,  G11B7/0045 ,  G11B7/0055 ,  G11B7/007 ,  G11B7/013 ,  G11B11/10 ,  G11B11/105 ,  G11B20/12 ,  G11B27/19

Abstract: Rewriteable media, such as magnetooptic record members or disk has its recording controlled such that the recording is certifiable as meeting write once read many characteristics. Controls are introduced for the entire disk for indicating that the rewriteable disk is to be used for certified or vault writing, at least in some radial zones of the disk. Recording or writing operations are limited to those addressable areas on the certifiable rewriteable medium that have not been previously written. Each of the addressable areas of the medium, in a disk termed, sectors, have a precursor portion called a control area which indicates the status of the sector and is used for preventing overwriting or erasure as well as controlling.

公开(公告)号：CA2026740C

公开(公告)日：1995-08-29

申请号：CA2026740

申请日：1990-10-02

Applicant: IBM

Inventor： TAYEFEH MOROVAT

IPC: G11B11/10 ,  G11B11/105 ,  G11B19/02 ,  G11B27/36 ,  G11B11/14

Abstract: A magnetooptic storage member is scanned by a single laser beam. The beam intensity is sufficient to heat a localized area of the storage member to be above the Curie temperature for enabling reversing the remanent magnetization of the localized area. Such localized area is subjected to a magnetic bias field for directing which of the remanent directions shall be assumed in the localized area. The storage member and laser beam are relatively moved such that a front or leading portion of the localized area does not reach the Curie temperature. The light reflected from this leading portion, which moves with the laser beam relative to the storage member, is detected for indicating the initial remanent state of the localized area before any changes are made by the combination of the bias field and the laser beam.

公开(公告)号：DE69016246D1

公开(公告)日：1995-03-09

申请号：DE69016246

申请日：1990-04-04

Applicant: IBM

Inventor： BLETSHER WARREN LEROY ,  TAYEFEH MOROVAT ,  LEWKOWICZ JULIAN

IPC: G11B11/10 ,  G11B7/00 ,  G11B7/0045 ,  G11B7/125 ,  G11B11/105 ,  G11B27/36 ,  G11B7/12

Abstract: Recording operations for an optical disk recorder are calibrated by adjusting recording power level (light intensity) such that a permissible crosstalk can be detected in adjacent erased tracks. Following the power level calibration, pulse duration or width is calibrated for a predetermined symmetry of recorded pulses along the calibration track. Various sequences and procedures are described. Calibration occurs at a plurality of radially spaced-apart tracks.

公开(公告)号：CA2046704A1

公开(公告)日：1992-03-29

申请号：CA2046704

申请日：1991-07-10

Applicant: IBM

Inventor： FENNEMA ALAN A ,  FINKELSTEIN BLAIR I ,  TAYEFEH MOROVAT ,  YARDY RAYMOND

IPC: G11B7/00 ,  G11B7/004 ,  G11B7/0045 ,  G11B7/085 ,  G11B7/09 ,  G11B7/125 ,  G11B11/10 ,  G11B11/105 ,  G11B19/12

公开(公告)号：CA2046705A1

公开(公告)日：1992-03-25

申请号：CA2046705

申请日：1991-07-10

Applicant: IBM

Inventor： KULAKOWSKI JOHN E ,  MEANS RODNEY J ,  TAYEFEH MOROVAT

IPC: G11B7/00 ,  G11B7/0045 ,  G11B7/0055 ,  G11B7/007 ,  G11B7/013 ,  G11B11/10 ,  G11B11/105 ,  G11B20/12

Abstract: The present invention relates to a re-writable data storage member (10) comprising a plurality of spaced apart addressable data storage areas (12) for recording and storing data and a plurality of non-data storage areas (15) interposed between adjacent ones of the addressable data storage areas for recording signals not representing data, the storage member being adapted to be scanned in a direction over the storage areas. According to the invention the storage member is characterised in that one of the addressable data storage areas contains first machine readable indicia indicating that the storage member contains data which is not to be changed from any original recording of the data, another of the addressable data storage areas contains second machine readable indicia indicating whether or not the storage member has been erased of data in its entirety, and each of the non-data storage areas contains third machine readable indicia indicating whether or not one of the respective adjacent addressable data storage areas can be written into. The invention also relates to a data storage system comprising a re-writable data storage member as above and to a method of operating such a data storage system.

公开(公告)号：DE69120757T2

公开(公告)日：1997-01-23

申请号：DE69120757

申请日：1991-09-16

Applicant: IBM

Inventor： KULAKOWSKI JOHN EDWARD ,  MEANS RODNEY JEROME ,  TAYEFEH MOROVAT

IPC: G11B7/00 ,  G11B7/0045 ,  G11B7/0055 ,  G11B7/007 ,  G11B7/013 ,  G11B11/10 ,  G11B11/105 ,  G11B20/12

Abstract: The present invention relates to a re-writable data storage member (10) comprising a plurality of spaced apart addressable data storage areas (12) for recording and storing data and a plurality of non-data storage areas (15) interposed between adjacent ones of the addressable data storage areas for recording signals not representing data, the storage member being adapted to be scanned in a direction over the storage areas. According to the invention the storage member is characterised in that one of the addressable data storage areas contains first machine readable indicia indicating that the storage member contains data which is not to be changed from any original recording of the data, another of the addressable data storage areas contains second machine readable indicia indicating whether or not the storage member has been erased of data in its entirety, and each of the non-data storage areas contains third machine readable indicia indicating whether or not one of the respective adjacent addressable data storage areas can be written into. The invention also relates to a data storage system comprising a re-writable data storage member as above and to a method of operating such a data storage system.

公开(公告)号：DE69304068D1

公开(公告)日：1996-09-19

申请号：DE69304068

申请日：1993-05-19

Applicant: IBM

Inventor： JAQUETTE GLEN ,  TAYEFEH MOROVAT

IPC: G11B11/10 ,  G11B7/005 ,  G11B7/13 ,  G11B11/105 ,  G11B13/00 ,  G11B13/04

Abstract: A circuit for simultaneously detecting both MO and ROM signals reflected from an optical disk so that both signals are present and useable without switching from one to the other. The circuit eliminates switching time and switching transients. Two photodetectors are arranged to sense P and S components of polarized light in order to stimulate a differential amplifier and produce an output representative of MO recorded data. A second amplifier is connected to at least one of the photodetectors to produce an output representative of ROM recorded data and also representative of defects in the MO portion of the optical disk.

公开(公告)号：DE69116039D1

公开(公告)日：1996-02-15

申请号：DE69116039

申请日：1991-03-01

Applicant: IBM

Inventor： FINKELSTEIN BLAIR IAN ,  TAYEFEH MOROVAT ,  UENO HIDEO

IPC: G11B7/00 ,  G11B7/0045 ,  G11B7/0055 ,  G11B7/125 ,  G11B11/10 ,  G11B11/105 ,  G11B20/18 ,  G11B27/36

Abstract: The present invention relates to a method of calibrating a system for the recording and readback of optically detectable data of the type which comprises a record medium (30) formed from a material which is sensitive to optical radiation, means (67) for generating a beam of light (47), means (33) for scanning the beam of light relative to the surface of the medium, means (75) for selectively varying the intensity of the beam of light so as to record data at selected positions on the surface and means (79) for reading back the recorded data. The calibrating method comprises the operation of controlling the recording intensity of the beam of light so that signals from the readback means have a maximum amplitude. According to the invention the operation of controlling the recording intensity comprises utilising the beam of light to record a plurality of test patterns (29) on the surface of the medium each pattern being recorded with a different intensity of the beam of light, reading back the test patterns and generating a readback test signal from each test pattern, detecting the readback test signal having the largest amplitude, and utilising the intensity of the beam of light used to record the test pattern which generates the readback test signal having the largest amplitude for the light beam when it is recording data. The invention also relates to apparatus for implementing the above method of calibrating.

公开(公告)号：CA2046704C

公开(公告)日：1995-09-26

申请号：CA2046704

申请日：1991-07-10

Applicant: IBM

Inventor： FENNEMA ALAN AUGUST ,  FINKELSTEIN BLAIR IAN ,  TAYEFEH MOROVAT ,  YARDY RAYMOND

IPC: G11B7/00 ,  G11B7/004 ,  G11B7/0045 ,  G11B7/085 ,  G11B7/09 ,  G11B7/125 ,  G11B11/10 ,  G11B11/105 ,  G11B19/12 ,  G11B27/19

Abstract: An optical disk recorder is capable of operating with diverse types of optical media. An device initialization procedure is repeated for each receipt of each optical medium. Such procedure includes moving a objective lens to an extreme radial position, defocussing the lens at a most remote position, then calibrating the laser circuits to ensure that the emission of radiation from the laser will not inadvertently destroy signals recorded on the just received medium. Then the medium type is read from the medium and based upon the type indication, various additional calibrating procedures are followed and different sources of laser control values are used for signal exchanging operations between the recorder and received optical medium.