FR2339228A1 - Optical readout system for magnetic recording - uses linearly polarised beam directed through recording medium with polarisation plane changed by magnetisation - Google Patents

Optical readout system for magnetic recording - uses linearly polarised beam directed through recording medium with polarisation plane changed by magnetisation

Info

Publication number
FR2339228A1
FR2339228A1 FR7601327A FR7601327A FR2339228A1 FR 2339228 A1 FR2339228 A1 FR 2339228A1 FR 7601327 A FR7601327 A FR 7601327A FR 7601327 A FR7601327 A FR 7601327A FR 2339228 A1 FR2339228 A1 FR 2339228A1
Authority
FR
France
Prior art keywords
magnetisation
linearly polarised
recording medium
beam directed
polarisation plane
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
FR7601327A
Other languages
French (fr)
Other versions
FR2339228B1 (en
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.)
Kodak Pathe SA
Original Assignee
Kodak Pathe SA
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 Kodak Pathe SA filed Critical Kodak Pathe SA
Priority to FR7601327A priority Critical patent/FR2339228A1/en
Publication of FR2339228A1 publication Critical patent/FR2339228A1/en
Application granted granted Critical
Publication of FR2339228B1 publication Critical patent/FR2339228B1/fr
Granted legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
    • G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/03—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on ceramics or electro-optical crystals, e.g. exhibiting Pockels effect or Kerr effect
    • G02F1/0327—Operation of the cell; Circuit arrangements

Abstract

The optical read-out system is used for information recorded magnetically on a tape or disc. It employs a linearly polarised light beam, directed through the recording tape etc. so that the polarisation plane is rotated in dependence on the magnetisation. The read-out system has a light source (1, 2) providing the linearly polarised beam and an electro-optical modulator (3) supplied with a signal of given frequency. The tape is moved relative to the beam such that its magnetisation vector has a component along the optical axis of the beam. An analyser prism (7) receives the modulated beam and is followed by a photodetector (8) supplying a signal to a phase detector (12) also receiving the signal supplied to the electro-optical modulator (3).
FR7601327A 1976-01-20 1976-01-20 Optical readout system for magnetic recording - uses linearly polarised beam directed through recording medium with polarisation plane changed by magnetisation Granted FR2339228A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
FR7601327A FR2339228A1 (en) 1976-01-20 1976-01-20 Optical readout system for magnetic recording - uses linearly polarised beam directed through recording medium with polarisation plane changed by magnetisation

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR7601327A FR2339228A1 (en) 1976-01-20 1976-01-20 Optical readout system for magnetic recording - uses linearly polarised beam directed through recording medium with polarisation plane changed by magnetisation

Publications (2)

Publication Number Publication Date
FR2339228A1 true FR2339228A1 (en) 1977-08-19
FR2339228B1 FR2339228B1 (en) 1979-07-06

Family

ID=9168102

Family Applications (1)

Application Number Title Priority Date Filing Date
FR7601327A Granted FR2339228A1 (en) 1976-01-20 1976-01-20 Optical readout system for magnetic recording - uses linearly polarised beam directed through recording medium with polarisation plane changed by magnetisation

Country Status (1)

Country Link
FR (1) FR2339228A1 (en)

Also Published As

Publication number Publication date
FR2339228B1 (en) 1979-07-06

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Legal Events

Date Code Title Description
ST Notification of lapse