JPS56111136A - Protective device for reader of optical disc player - Google Patents

Protective device for reader of optical disc player

Info

Publication number
JPS56111136A
JPS56111136A JP1110680A JP1110680A JPS56111136A JP S56111136 A JPS56111136 A JP S56111136A JP 1110680 A JP1110680 A JP 1110680A JP 1110680 A JP1110680 A JP 1110680A JP S56111136 A JPS56111136 A JP S56111136A
Authority
JP
Japan
Prior art keywords
output
disc
focus
reader
signal
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
JP1110680A
Other languages
Japanese (ja)
Inventor
Takashi Okano
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.)
Pioneer Video Corp
Universal Pioneer Corp
Original Assignee
Pioneer Video Corp
Universal Pioneer Corp
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 Pioneer Video Corp, Universal Pioneer Corp filed Critical Pioneer Video Corp
Priority to JP1110680A priority Critical patent/JPS56111136A/en
Publication of JPS56111136A publication Critical patent/JPS56111136A/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

Landscapes

  • Moving Of The Head For Recording And Reproducing By Optical Means (AREA)
  • Automatic Focus Adjustment (AREA)

Abstract

PURPOSE:To prevent the disc and reader from coming into contact with each other, by detecting that the optical reader is too closely approached to the disc, through the comparison of the signal from two tracking photodetectors with the reference level by addition. CONSTITUTION:When an H signal is input from a terminal 24, a focus motor 12 is driven, the focus lens and disc are brought into contact with each other, and the level of the 1st and 2nd sum signals 6 and 7 of the photodetector 1 is the same when the focus is in coincidence, and the output of a differential amplifier 8 is zero. On the other hand, the output signal of the sum of tracking photodetectors 13, 14 is compared with a given potential at all times at the comparator 17, and the output S is changed as the focus lens approaches the disc. Further, when a focus error signal K is output from the differential amplifier 8, a switch 9 is controlled with the output S of the comparator 17 for the control of the focus motor 12.
JP1110680A 1980-02-01 1980-02-01 Protective device for reader of optical disc player Pending JPS56111136A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP1110680A JPS56111136A (en) 1980-02-01 1980-02-01 Protective device for reader of optical disc player

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP1110680A JPS56111136A (en) 1980-02-01 1980-02-01 Protective device for reader of optical disc player

Publications (1)

Publication Number Publication Date
JPS56111136A true JPS56111136A (en) 1981-09-02

Family

ID=11768754

Family Applications (1)

Application Number Title Priority Date Filing Date
JP1110680A Pending JPS56111136A (en) 1980-02-01 1980-02-01 Protective device for reader of optical disc player

Country Status (1)

Country Link
JP (1) JPS56111136A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4546460A (en) * 1981-10-22 1985-10-08 Tokyo Shibaura Denki Kabushiki Kaisha Videodisc autofocus device
JPS6121018U (en) * 1984-07-11 1986-02-06 ソニー株式会社 Optical disk damage prevention device
JPS61264518A (en) * 1985-05-20 1986-11-22 Hitachi Ltd Focus leading-in device of optical disc player

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5128720A (en) * 1974-09-04 1976-03-11 Mitsubishi Electric Corp
JPS53132308A (en) * 1977-04-22 1978-11-18 Sony Corp Focus controller of optical reproducer
JPS54123918A (en) * 1978-03-18 1979-09-26 Victor Co Of Japan Ltd Automatic focus control unit in optical reproducer of information recording medium discs

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5128720A (en) * 1974-09-04 1976-03-11 Mitsubishi Electric Corp
JPS53132308A (en) * 1977-04-22 1978-11-18 Sony Corp Focus controller of optical reproducer
JPS54123918A (en) * 1978-03-18 1979-09-26 Victor Co Of Japan Ltd Automatic focus control unit in optical reproducer of information recording medium discs

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4546460A (en) * 1981-10-22 1985-10-08 Tokyo Shibaura Denki Kabushiki Kaisha Videodisc autofocus device
JPS6121018U (en) * 1984-07-11 1986-02-06 ソニー株式会社 Optical disk damage prevention device
JPH0411219Y2 (en) * 1984-07-11 1992-03-19
JPS61264518A (en) * 1985-05-20 1986-11-22 Hitachi Ltd Focus leading-in device of optical disc player

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