JPS57181440A - Information recorder and reproducer - Google Patents

Information recorder and reproducer

Info

Publication number
JPS57181440A
JPS57181440A JP57056604A JP5660482A JPS57181440A JP S57181440 A JPS57181440 A JP S57181440A JP 57056604 A JP57056604 A JP 57056604A JP 5660482 A JP5660482 A JP 5660482A JP S57181440 A JPS57181440 A JP S57181440A
Authority
JP
Japan
Prior art keywords
reproduction
recording
light
head
modulator
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.)
Pending
Application number
JP57056604A
Other languages
Japanese (ja)
Inventor
Yoshito Tsunoda
Toshimitsu Miyauchi
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.)
Hitachi Ltd
Original Assignee
Hitachi Ltd
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 Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP57056604A priority Critical patent/JPS57181440A/en
Publication of JPS57181440A publication Critical patent/JPS57181440A/en
Pending legal-status Critical Current

Links

Classifications

    • 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
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/125—Optical beam sources therefor, e.g. laser control circuitry specially adapted for optical storage devices; Modulators, e.g. means for controlling the size or intensity of optical spots or optical traces
    • G11B7/126—Circuits, methods or arrangements for laser control or stabilisation

Landscapes

  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Optical Head (AREA)

Abstract

PURPOSE:To use an optical head both for recording and reproduction, by providing a means that the amount of light from a light source is increased at recording and it is decreased at reproduction. CONSTITUTION:A light flux outputted from a laser source 9 is condensed on a disc 14 as a fine light spot after passing through a modulator 10 and a beam splitter 11. In using an optical head as a reproducing head, the optical output is decreased to a degree sufficient for reproduction. To decrease the amount of light, a DC voltage applied to the modulator 10 is changed to lower the degree of modulation. In using the said head as recording head, a signal from an information source 7 is given to the photomodulator 10 and the modulated laser beam is given on the disc for recording. The average output in this case is about 10 times that at reproduction.
JP57056604A 1982-04-07 1982-04-07 Information recorder and reproducer Pending JPS57181440A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP57056604A JPS57181440A (en) 1982-04-07 1982-04-07 Information recorder and reproducer

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP57056604A JPS57181440A (en) 1982-04-07 1982-04-07 Information recorder and reproducer

Related Child Applications (1)

Application Number Title Priority Date Filing Date
JP13114287A Division JPS6352332A (en) 1987-05-29 1987-05-29 Information recording and reproducing device

Publications (1)

Publication Number Publication Date
JPS57181440A true JPS57181440A (en) 1982-11-08

Family

ID=13031823

Family Applications (1)

Application Number Title Priority Date Filing Date
JP57056604A Pending JPS57181440A (en) 1982-04-07 1982-04-07 Information recorder and reproducer

Country Status (1)

Country Link
JP (1) JPS57181440A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0182127A2 (en) * 1984-11-19 1986-05-28 International Business Machines Corporation System for preventing the overwriting of previously optically recorded data and for reading optically recorded data during writing

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5280802A (en) * 1975-12-26 1977-07-06 Matsushita Electric Ind Co Ltd Optical type information recording and reproduction apparatus

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5280802A (en) * 1975-12-26 1977-07-06 Matsushita Electric Ind Co Ltd Optical type information recording and reproduction apparatus

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0182127A2 (en) * 1984-11-19 1986-05-28 International Business Machines Corporation System for preventing the overwriting of previously optically recorded data and for reading optically recorded data during writing

Similar Documents

Publication Publication Date Title
EP0559391A3 (en) Magnetooptical recording/reproducing apparatus
MY131532A (en) Recording medium having track formed of land portion and groove portion, and reproducing apparatus therefor
EP0411120A4 (en) Laser reproduction apparatus.
EP0498455A3 (en) Magneto-optic recording method and magneto-optic recording/reproducing apparatus
GB1372082A (en) Record and playback apparatus for pulse width modulated record
AU636905B2 (en) Cutting apparatus for an optical disc
EP0210275B1 (en) Recording/reproducing apparatus using magneto-optical disk
DE69321380T2 (en) Magneto-optical information recording and playback device
JPS647327A (en) Method and apparatus for optical information recording
JPS57181440A (en) Information recorder and reproducer
KR960002296A (en) Digital data recording method, digital data recording device, digital data recording and reproducing device
JPS55125546A (en) Information recorder
JPS60243832A (en) Optical information detecting device
JPS5715204A (en) Photomagnetic recording and reproducing device
JPS57203233A (en) Optical recorder and reproducer
KR100239830B1 (en) Apparatus for reproducing address data on a disc
JPS6053373B2 (en) Image signal reproduction optical power drift control method
JPS5348504A (en) Optical recorder/reproducer
JPS57179953A (en) Optical reproducing system
JPS54137219A (en) Record/reproduction system for information signal
JPS5778638A (en) Optical recording method
JPS56156814A (en) Synchronizing system for optical printer
JPS5744232A (en) Optical recorder and reproducer
JPS56119941A (en) Recording, reproducing and erasing apparatus of optical information
JPS5250649A (en) Optical information record reproduction device