GB1391541A - Information carrier of disc form for sound and/or video signals - Google Patents

Information carrier of disc form for sound and/or video signals

Info

Publication number
GB1391541A
GB1391541A GB948772A GB948772A GB1391541A GB 1391541 A GB1391541 A GB 1391541A GB 948772 A GB948772 A GB 948772A GB 948772 A GB948772 A GB 948772A GB 1391541 A GB1391541 A GB 1391541A
Authority
GB
United Kingdom
Prior art keywords
record
light
blocks
detector
reflection
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.)
Expired
Application number
GB948772A
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.)
Philips Electronics UK Ltd
Original Assignee
Philips Electronic and Associated Industries 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 Philips Electronic and Associated Industries Ltd filed Critical Philips Electronic and Associated Industries Ltd
Publication of GB1391541A publication Critical patent/GB1391541A/en
Expired 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
    • G11B7/004—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
    • G11B7/013—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 for discrete information, i.e. where each information unit is stored in a distinct discrete location, e.g. digital information formats within a data block or sector
    • 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
    • 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
    • G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector

Landscapes

  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Optical Recording Or Reproduction (AREA)
  • Optical Head (AREA)
  • Electrochromic Elements, Electrophoresis, Or Variable Reflection Or Absorption Elements (AREA)
  • Optical Record Carriers And Manufacture Thereof (AREA)

Abstract

1391541 Record carriers; optical playback apparatus PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd 1 March 1972 [4 March 1971] 9487/72 Heading G5R [Also in Divisions G2 and G1] A disc record carrier 1 has spiral or concentric tracks 12, 13 in which audio and/or video information in the form of frequency-modulated or phase-modulated signals is stored as a crenellated structure 3-7 in which the upstanding blocks 3, 5, 7 have different lengths and spacings and have a height comparable to optical wavelengths. The record may be of, e.g. polyvinyl acetate, made lithographically, or by photographic and etching methods. The blocks 3, 5, 7 preferably have a coefficient of reflection or transmission equal to that of the intervening areas 4, 6. The record 1 is played back optically by transmission or reflection as the disc is rotated. As shown, light from a source 20 passes through a polarizer 21, a Wollaston prism 22 and the record 1, and is focused on a detector 23 by a lens 25 via a second Wollaston prism 24 and an analyser 26. The prism 24 splits the beam into two diverging perpendicularly-polarized beams with intensities which may differ due to the varying path length of the light in the record 1. The prisms 22, 24 may be replaced by Savart plates having the same function. In an alternative arrangment, Fig. 3 (not shown) a Michelson interferometer (32) splits the transmitted beam. In a further embodiment, Fig. 4 (not shown) the record is illuminated with a collimated beam to produce diffraction. The + 1st and - 1st order beams are phase-shifted by 90 degrees relative to the zero order beam by a phase plate (68) and are combined by a lens (67). The tracks may alternatively be scanned by a focused point of light, Fig. 6 (not shown). In a reflection arrangement, Fig. 5 (not shown) light scattered by the side faces of the blocks 3, 5, 7 is focused on a detector (73) by an annular lens (75). A suitable light source is a laser, photo-diode or gas discharge tube. A suitable detector is a photomultiplier or solid-state device.
GB948772A 1971-03-04 1972-03-01 Information carrier of disc form for sound and/or video signals Expired GB1391541A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
NL7102863A NL7102863A (en) 1971-03-04 1971-03-04

Publications (1)

Publication Number Publication Date
GB1391541A true GB1391541A (en) 1975-04-23

Family

ID=19812612

Family Applications (1)

Application Number Title Priority Date Filing Date
GB948772A Expired GB1391541A (en) 1971-03-04 1972-03-01 Information carrier of disc form for sound and/or video signals

Country Status (15)

Country Link
JP (2) JPS544603B1 (en)
AR (2) AR195275A1 (en)
AT (1) AT342122B (en)
AU (1) AU470672B2 (en)
BE (1) BE780146A (en)
BR (1) BR7201206D0 (en)
CA (1) CA1023855A (en)
CH (2) CH552920A (en)
ES (1) ES400336A1 (en)
FR (1) FR2128576B1 (en)
GB (1) GB1391541A (en)
IT (1) IT952884B (en)
NL (1) NL7102863A (en)
NO (1) NO139905C (en)
ZA (1) ZA721137B (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4125401A (en) * 1976-10-20 1978-11-14 U.S. Philips Corporation Method of making copies of information tracks on carriers

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2197495A5 (en) * 1972-08-25 1974-03-22 Thomson Csf
NL7212015A (en) * 1972-09-04 1974-03-06
FR2235354A1 (en) * 1973-06-29 1975-01-24 Thomson Csf Photoelectric optical test sensor - measures displacement of a diffraction screen with constant spacing in the test sensor plane
BE871326A (en) * 1978-10-23 1979-04-17 Mca Disco Vision METHOD AND DEVICE FOR RECORDING AND REPRODUCING A VIDEO SIGNAL.

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4125401A (en) * 1976-10-20 1978-11-14 U.S. Philips Corporation Method of making copies of information tracks on carriers

Also Published As

Publication number Publication date
ATA166672A (en) 1977-07-15
NO139905C (en) 1979-05-30
IT952884B (en) 1973-07-30
DE2208379B2 (en) 1976-10-28
AU3945472A (en) 1973-08-30
ES400336A1 (en) 1975-06-16
AR195275A1 (en) 1973-09-28
BE780146A (en) 1972-09-04
NO139905B (en) 1979-02-19
CH553522A (en) 1974-08-30
JPS544603B1 (en) 1979-03-08
AT342122B (en) 1978-03-10
BR7201206D0 (en) 1973-06-07
AU470672B2 (en) 1973-08-30
AR203718A1 (en) 1975-10-15
CA1023855A (en) 1978-01-03
CH552920A (en) 1974-08-15
NL7102863A (en) 1972-09-06
JPS5732409B2 (en) 1982-07-10
DE2208379A1 (en) 1972-09-14
ZA721137B (en) 1973-10-31
FR2128576A1 (en) 1972-10-20
JPS5452504A (en) 1979-04-25
FR2128576B1 (en) 1980-03-14

Similar Documents

Publication Publication Date Title
US4041530A (en) Video disc with phase structure
KR920701952A (en) Optical recording and / or reproducing apparatus
JPS57147148A (en) Information reproducer with magnetooptic system
KR840005877A (en) Optical playback device
GB1499562A (en) Optical record reader
GB1529954A (en) Optically readable records and reading apparatus therefor
US4160269A (en) Apparatus for optically reading a phase-modulated optical record carrier
KR910008670A (en) Optical head for optical information recording and reproduction
GB1392796A (en) Optical signal reproducing apparatus
MY118249A (en) Optical pickup device and disk player apparatus
GB1391541A (en) Information carrier of disc form for sound and/or video signals
YU177184A (en) Device for information reproduction from optical readable information carrier
CA2108766A1 (en) Phase-Change Type Optical Disk Device and Optical Head to be Used Therein
JPS62137736A (en) Optical head device
HUT60561A (en) Magnetooptic recording and/or reproducing apparatus
JPS5755568A (en) Recording and reproducing device
CA1063241A (en) Carrier provided with a spiral structure in which sound and/or image information is stored
JPS56145532A (en) Optical information recording and reproducing device
KR100556692B1 (en) Reproductive Apparatus For Optical Disc
JPH073461Y2 (en) Optical pickup device
SU570906A1 (en) Optical modulation correlometer for analizing linear fm signals
JPS6254845A (en) Optical pickup device
JPH04258814A (en) Light reproducing device
JPS63146243A (en) Optical head device
CA2014163A1 (en) Optical recording and reproducing apparatus

Legal Events

Date Code Title Description
PS Patent sealed
PE20 Patent expired after termination of 20 years