JPS55101141A - Automatic focusing unit in optical information reproducing device - Google Patents

Automatic focusing unit in optical information reproducing device

Info

Publication number
JPS55101141A
JPS55101141A JP567279A JP567279A JPS55101141A JP S55101141 A JPS55101141 A JP S55101141A JP 567279 A JP567279 A JP 567279A JP 567279 A JP567279 A JP 567279A JP S55101141 A JPS55101141 A JP S55101141A
Authority
JP
Japan
Prior art keywords
optical axis
lens
displaced
automatic focusing
reflection
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
JP567279A
Other languages
Japanese (ja)
Other versions
JPS6012693B2 (en
Inventor
Fumio Akuwa
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.)
Victor Company of Japan Ltd
Original Assignee
Victor Company of Japan 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 Victor Company of Japan Ltd filed Critical Victor Company of Japan Ltd
Priority to JP567279A priority Critical patent/JPS6012693B2/en
Publication of JPS55101141A publication Critical patent/JPS55101141A/en
Publication of JPS6012693B2 publication Critical patent/JPS6012693B2/en
Expired 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 perform a high-precision automatic focusing with a simple constitution by causing the reflection laser light flux from an information recording medium pass through a lens displaced for the optical axis and by converting focus slippage to optical axis slippage to detect it. CONSTITUTION:Lens 9 is a normal convex lens, and lens axis line 9a is arranged in a position displaced from optical axis 7a of reflection laser light flux 7 from semi- transparent mirror 4 by distance x in parallel with optical axis 7a. Conjugate points are displaced on the reflection optical axis according to surface vibration of video disc 6 which rotates in a high speed, and the reflection optical axis is shifted according to the position of conjugate points by convex lens 9, and a round spot is displaced on photo detector 8 without changing the form. Output difference between a pair of photo detection elements 8a and 8b displaces read lens 5 to perform focusing, so that automatic focusing can be performed with a high precision without a beam used only for focus detection.
JP567279A 1979-01-22 1979-01-22 Automatic focusing device in optical information reproducing device Expired JPS6012693B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP567279A JPS6012693B2 (en) 1979-01-22 1979-01-22 Automatic focusing device in optical information reproducing device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP567279A JPS6012693B2 (en) 1979-01-22 1979-01-22 Automatic focusing device in optical information reproducing device

Publications (2)

Publication Number Publication Date
JPS55101141A true JPS55101141A (en) 1980-08-01
JPS6012693B2 JPS6012693B2 (en) 1985-04-03

Family

ID=11617584

Family Applications (1)

Application Number Title Priority Date Filing Date
JP567279A Expired JPS6012693B2 (en) 1979-01-22 1979-01-22 Automatic focusing device in optical information reproducing device

Country Status (1)

Country Link
JP (1) JPS6012693B2 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5752005A (en) * 1980-08-19 1982-03-27 Olympus Optical Co Ltd Focus detecting method
JPS58199447A (en) * 1982-05-14 1983-11-19 Hitachi Ltd Photodetector of optical reader
JPS60263341A (en) * 1984-06-12 1985-12-26 Toshiba Corp Optical head
JPS61148632A (en) * 1984-12-20 1986-07-07 Fujitsu Ltd Focus control signal detecting system of optical disk device

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5752005A (en) * 1980-08-19 1982-03-27 Olympus Optical Co Ltd Focus detecting method
JPH0372965B2 (en) * 1980-08-19 1991-11-20 Olympus Optical Co
JPS58199447A (en) * 1982-05-14 1983-11-19 Hitachi Ltd Photodetector of optical reader
JPH057769B2 (en) * 1982-05-14 1993-01-29 Hitachi Ltd
JPS60263341A (en) * 1984-06-12 1985-12-26 Toshiba Corp Optical head
JPS61148632A (en) * 1984-12-20 1986-07-07 Fujitsu Ltd Focus control signal detecting system of optical disk device

Also Published As

Publication number Publication date
JPS6012693B2 (en) 1985-04-03

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