JPS567248A - Position detecting system - Google Patents

Position detecting system

Info

Publication number
JPS567248A
JPS567248A JP8262879A JP8262879A JPS567248A JP S567248 A JPS567248 A JP S567248A JP 8262879 A JP8262879 A JP 8262879A JP 8262879 A JP8262879 A JP 8262879A JP S567248 A JPS567248 A JP S567248A
Authority
JP
Japan
Prior art keywords
photodetectors
quadrangular pyramid
pyramid prism
objective lens
reflection light
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
JP8262879A
Other languages
Japanese (ja)
Inventor
Hiroshi Futagami
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 JP8262879A priority Critical patent/JPS567248A/en
Publication of JPS567248A publication Critical patent/JPS567248A/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
    • G11B7/0908—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 focusing only

Abstract

PURPOSE:To improve the position detection precision, by receiving a reflection light through a quadrangular pyramid prism by plural photodetectors and by detecting relative positions of a recording medium and an objective lens on the basis of outputs of respective photodetectors. CONSTITUTION:The reflection light from recording medium 3 is incident to regularly quadrangular pyramid prism 11 from the top side through objective lens 2, beam splitter 1, and condenser lens 4 and is divided to four upper, lower, left and right directions and advances toward corresponding condensing points. The reflection light which passed through quadrangular pyramid prism 11 is received by photodetectors 12-15 provided in different positions in the bottom face side of quadrangular pyramid prism 11, and relative positions of the surface of ibject 3 and objective lens 2 are detected by monitoring output levels of photodetectors 12-15.
JP8262879A 1979-07-02 1979-07-02 Position detecting system Pending JPS567248A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP8262879A JPS567248A (en) 1979-07-02 1979-07-02 Position detecting system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP8262879A JPS567248A (en) 1979-07-02 1979-07-02 Position detecting system

Publications (1)

Publication Number Publication Date
JPS567248A true JPS567248A (en) 1981-01-24

Family

ID=13779703

Family Applications (1)

Application Number Title Priority Date Filing Date
JP8262879A Pending JPS567248A (en) 1979-07-02 1979-07-02 Position detecting system

Country Status (1)

Country Link
JP (1) JPS567248A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4501493A (en) * 1982-10-28 1985-02-26 Sony Corporation Apparatus for detecting a position of an optical pickup
EP0201917A2 (en) * 1985-05-15 1986-11-20 Kabushiki Kaisha Toshiba Optical system for an optical memory

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS54140533A (en) * 1978-04-14 1979-10-31 Philips Nv Focus error detector

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS54140533A (en) * 1978-04-14 1979-10-31 Philips Nv Focus error detector

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4501493A (en) * 1982-10-28 1985-02-26 Sony Corporation Apparatus for detecting a position of an optical pickup
EP0201917A2 (en) * 1985-05-15 1986-11-20 Kabushiki Kaisha Toshiba Optical system for an optical memory

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