JPS57191839A - Information reader - Google Patents

Information reader

Info

Publication number
JPS57191839A
JPS57191839A JP56076346A JP7634681A JPS57191839A JP S57191839 A JPS57191839 A JP S57191839A JP 56076346 A JP56076346 A JP 56076346A JP 7634681 A JP7634681 A JP 7634681A JP S57191839 A JPS57191839 A JP S57191839A
Authority
JP
Japan
Prior art keywords
signal
axis
couple
depth
disk
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
JP56076346A
Other languages
Japanese (ja)
Inventor
Nobuyuki Kaneko
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.)
TRIO KENWOOD CORP
Trio KK
Kenwood KK
Original Assignee
TRIO KENWOOD CORP
Trio KK
Kenwood KK
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 TRIO KENWOOD CORP, Trio KK, Kenwood KK filed Critical TRIO KENWOOD CORP
Priority to JP56076346A priority Critical patent/JPS57191839A/en
Publication of JPS57191839A publication Critical patent/JPS57191839A/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
    • G11B7/08—Disposition or mounting of heads or light sources relatively to record carriers
    • G11B7/09—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
    • G11B7/0901—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam or focus plane for the purpose of maintaining alignment of the light beam relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following for track following only
    • G11B7/0906—Differential phase difference systems
    • 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

Landscapes

  • Optical Recording Or Reproduction (AREA)

Abstract

PURPOSE:To derive the best information read signal and a tracking error signal from an information read beam according to the depth of pits, by arranging a couple of photoelectric converting elements in such a way that they coincide with the optical axis of the objective lens for a disk. CONSTITUTION:A read beam from a laser 5 is modulated according to the depth of a pit 10 of a disk 1, and a total reflection beam from a reflecting film is caused to illuminate a photoelectric converting element couple 12. The element couple 12 are arranged on the surface where diffracted beams differing in degree among reflected beams are discriminated sufficiently, the origin O is set on the optical axis of an objective lens 7, and the X axis and Y axis of an orthogonal coordinate system coincide with the tangent and normal directions of a track 4. Outputs of the elements in the opposite quadrants are added at parts 13 and 14, and the sums are further processed by subtraction 15 and addition 16; the sum signal is led out as an RF signal and shifted in phase by 90 deg. at a part 17, and the resulting signal is multiplied by the subtraction output DF at a part 18, thereby outputting a tracking error signal eT through an LRF19.
JP56076346A 1981-05-20 1981-05-20 Information reader Pending JPS57191839A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP56076346A JPS57191839A (en) 1981-05-20 1981-05-20 Information reader

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP56076346A JPS57191839A (en) 1981-05-20 1981-05-20 Information reader

Publications (1)

Publication Number Publication Date
JPS57191839A true JPS57191839A (en) 1982-11-25

Family

ID=13602792

Family Applications (1)

Application Number Title Priority Date Filing Date
JP56076346A Pending JPS57191839A (en) 1981-05-20 1981-05-20 Information reader

Country Status (1)

Country Link
JP (1) JPS57191839A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1986005914A1 (en) * 1985-04-05 1986-10-09 Sony Corporation Tracking error detecting apparatus for optical disks
JPH07296395A (en) * 1994-04-27 1995-11-10 Victor Co Of Japan Ltd Tracking signal detecting method for information reproducing apparatus
US8085637B2 (en) 2008-09-30 2011-12-27 Sony Corporation Tracking error signal detection apparatus and optical disc apparatus

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1986005914A1 (en) * 1985-04-05 1986-10-09 Sony Corporation Tracking error detecting apparatus for optical disks
JPH07296395A (en) * 1994-04-27 1995-11-10 Victor Co Of Japan Ltd Tracking signal detecting method for information reproducing apparatus
US8085637B2 (en) 2008-09-30 2011-12-27 Sony Corporation Tracking error signal detection apparatus and optical disc apparatus

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