JPS5792439A - Optical recorder and reproducer - Google Patents

Optical recorder and reproducer

Info

Publication number
JPS5792439A
JPS5792439A JP16742580A JP16742580A JPS5792439A JP S5792439 A JPS5792439 A JP S5792439A JP 16742580 A JP16742580 A JP 16742580A JP 16742580 A JP16742580 A JP 16742580A JP S5792439 A JPS5792439 A JP S5792439A
Authority
JP
Japan
Prior art keywords
focus
signal
focus control
turn
comparator
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.)
Granted
Application number
JP16742580A
Other languages
Japanese (ja)
Other versions
JPH0644347B2 (en
Inventor
Tomio Yoshida
Isao Sato
Shunji Harikae
Kenji Koishi
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.)
Panasonic Holdings Corp
Original Assignee
Matsushita Electric Industrial Co 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 Matsushita Electric Industrial Co Ltd filed Critical Matsushita Electric Industrial Co Ltd
Priority to JP55167425A priority Critical patent/JPH0644347B2/en
Publication of JPS5792439A publication Critical patent/JPS5792439A/en
Publication of JPH0644347B2 publication Critical patent/JPH0644347B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G11INFORMATION STORAGE
    • G11BINFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00Recording 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
    • G11B7/08Disposition or mounting of heads or light sources relatively to record carriers
    • G11B7/09Disposition 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
    • G11B7/0945Methods for initialising servos, start-up sequences

Landscapes

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

Abstract

PURPOSE:To secure focus control by providing a means of starting, stopping and restarting the focus drawing operation of irradiating light according to the states of a focus control signal and a guide-track traverse signal. CONSTITUTION:When a signal FON is inputted to a terminal K, switches 24 and 26 turn on between terminals p2 and r2, and p3 and r3, allowing an aperture lens to approach a disk. When a focus error signal DI increases above the Vthl of a comparator and the disk is judged to be within focus drawing range, the signal Q1 of an FF29 goes down to an L to turn off switches 26 and 26, and a switch 22 turns on between terminals p1 and r1 to turn on a focus control loop I. As a recording material surface is brought under focus control, a guide- track traverse signal inputted to a terminal S decreases below the set value Vth2 of the comparator 37 and the delay pulse G of a delay pulse generating circuit 31 is intercepted by an AND gate 34 to hold a focus-controlled state, but when the signal S is high, the focus drawing operation is repeated through the output of the gate 34, thus performing the focus control securely.
JP55167425A 1980-11-27 1980-11-27 Optical recording / reproducing device Expired - Lifetime JPH0644347B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP55167425A JPH0644347B2 (en) 1980-11-27 1980-11-27 Optical recording / reproducing device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP55167425A JPH0644347B2 (en) 1980-11-27 1980-11-27 Optical recording / reproducing device

Publications (2)

Publication Number Publication Date
JPS5792439A true JPS5792439A (en) 1982-06-09
JPH0644347B2 JPH0644347B2 (en) 1994-06-08

Family

ID=15849454

Family Applications (1)

Application Number Title Priority Date Filing Date
JP55167425A Expired - Lifetime JPH0644347B2 (en) 1980-11-27 1980-11-27 Optical recording / reproducing device

Country Status (1)

Country Link
JP (1) JPH0644347B2 (en)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6148133A (en) * 1984-08-15 1986-03-08 Hitachi Ltd Optical disc device
JPS6149107A (en) * 1984-08-15 1986-03-11 Mitsubishi Heavy Ind Ltd Condenser vacuum reduction trip interlock circuit using pressure switch of steam turbine
JPS6168735A (en) * 1984-09-10 1986-04-09 Nakamichi Corp Focus servo actuation device for optical recording and reproduction
JPH0513242A (en) * 1991-06-29 1993-01-22 Hitachi Ferrite Ltd Rotary transformer
EP0618569A1 (en) * 1993-04-02 1994-10-05 Sony Corporation Focusing servo system and focus servo acquisition enable method

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS54128707A (en) * 1978-03-27 1979-10-05 Mca Disco Vision Focus servo device

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS54128707A (en) * 1978-03-27 1979-10-05 Mca Disco Vision Focus servo device

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6148133A (en) * 1984-08-15 1986-03-08 Hitachi Ltd Optical disc device
JPS6149107A (en) * 1984-08-15 1986-03-11 Mitsubishi Heavy Ind Ltd Condenser vacuum reduction trip interlock circuit using pressure switch of steam turbine
JPS6168735A (en) * 1984-09-10 1986-04-09 Nakamichi Corp Focus servo actuation device for optical recording and reproduction
JPH0513242A (en) * 1991-06-29 1993-01-22 Hitachi Ferrite Ltd Rotary transformer
EP0618569A1 (en) * 1993-04-02 1994-10-05 Sony Corporation Focusing servo system and focus servo acquisition enable method
US5745450A (en) * 1993-04-02 1998-04-28 Sony Corporation Focusing servo system and focus servo acquisition enable with multiple velocity acquisition modes
US5912867A (en) * 1993-04-02 1999-06-15 Sony Corporation Focusing servo system with focus servo acquisition enable which is operational within a predetermined time after the start of the movement of an objective lens

Also Published As

Publication number Publication date
JPH0644347B2 (en) 1994-06-08

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