JPS57167145A - Optical information reproducing device - Google Patents

Optical information reproducing device

Info

Publication number
JPS57167145A
JPS57167145A JP5108981A JP5108981A JPS57167145A JP S57167145 A JPS57167145 A JP S57167145A JP 5108981 A JP5108981 A JP 5108981A JP 5108981 A JP5108981 A JP 5108981A JP S57167145 A JPS57167145 A JP S57167145A
Authority
JP
Japan
Prior art keywords
laser beam
object lens
optical information
reproducing device
gain
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
JP5108981A
Other languages
Japanese (ja)
Inventor
Takashi Yamaguchi
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.)
Toshiba Corp
Original Assignee
Toshiba Corp
Tokyo Shibaura Electric 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 Toshiba Corp, Tokyo Shibaura Electric Co Ltd filed Critical Toshiba Corp
Priority to JP5108981A priority Critical patent/JPS57167145A/en
Publication of JPS57167145A publication Critical patent/JPS57167145A/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
    • G11B7/0941—Methods and circuits for servo gain or phase compensation during operation

Landscapes

  • Automatic Focus Adjustment (AREA)
  • Optical Recording Or Reproduction (AREA)

Abstract

PURPOSE:To focus a laser beam electrically, by provoding an operational amplifier which can vary the gain or the like of the output of a 4-split photodetector for receiving the reflection light. CONSTITUTION:The laser beam radiated from a semiconductor laser 11 is condensed to a minute spot by an object lens 16 and is returned to the optical path where the laser beam comes, and this laser beam is reflected by a beam splitter 12 and is received by a 4-split photodetector 19, and two pairs of sum signals are obtained by amplifiers 24, 25, 26, and 27 capable of gain control and offset control, and control signals of focusing tracking are obtained by differential amplifiers 28 and 29 and are sent to driving circuits 32 and 33 through phase compensating circuits 30 and 31 to move the object lens vertically and horizontally.
JP5108981A 1981-04-07 1981-04-07 Optical information reproducing device Pending JPS57167145A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP5108981A JPS57167145A (en) 1981-04-07 1981-04-07 Optical information reproducing device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP5108981A JPS57167145A (en) 1981-04-07 1981-04-07 Optical information reproducing device

Publications (1)

Publication Number Publication Date
JPS57167145A true JPS57167145A (en) 1982-10-14

Family

ID=12877082

Family Applications (1)

Application Number Title Priority Date Filing Date
JP5108981A Pending JPS57167145A (en) 1981-04-07 1981-04-07 Optical information reproducing device

Country Status (1)

Country Link
JP (1) JPS57167145A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60157731A (en) * 1984-01-27 1985-08-19 Matsushita Electric Ind Co Ltd Optical disk device
US6212152B1 (en) 1998-02-04 2001-04-03 Fujitsu Limited Optical information detection apparatus
JP2007226893A (en) * 2006-02-23 2007-09-06 Matsushita Electric Ind Co Ltd Optical disk device and its focus control method

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5573935A (en) * 1978-11-20 1980-06-04 Mansei Kogyo Kk Optical information reader

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5573935A (en) * 1978-11-20 1980-06-04 Mansei Kogyo Kk Optical information reader

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60157731A (en) * 1984-01-27 1985-08-19 Matsushita Electric Ind Co Ltd Optical disk device
US6212152B1 (en) 1998-02-04 2001-04-03 Fujitsu Limited Optical information detection apparatus
US6359851B2 (en) 1998-02-04 2002-03-19 Fujitsu Limited Optical information detection apparatus
JP2007226893A (en) * 2006-02-23 2007-09-06 Matsushita Electric Ind Co Ltd Optical disk device and its focus control method
JP4518031B2 (en) * 2006-02-23 2010-08-04 パナソニック株式会社 Optical disk device

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