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JPS5727444A - Focus detector - Google Patents

Focus detector

Info

Publication number
JPS5727444A
JPS5727444A JP10210680A JP10210680A JPS5727444A JP S5727444 A JPS5727444 A JP S5727444A JP 10210680 A JP10210680 A JP 10210680A JP 10210680 A JP10210680 A JP 10210680A JP S5727444 A JPS5727444 A JP S5727444A
Authority
JP
Japan
Prior art keywords
lens
light
flux
prism
turned
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
JP10210680A
Other languages
Japanese (ja)
Other versions
JPH0219537B2 (en
Inventor
Toru Musha
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.)
Olympus Corp
Original Assignee
Olympus Optical 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 Olympus Optical Co Ltd filed Critical Olympus Optical Co Ltd
Priority to JP10210680A priority Critical patent/JPS5727444A/en
Publication of JPS5727444A publication Critical patent/JPS5727444A/en
Publication of JPH0219537B2 publication Critical patent/JPH0219537B2/ja
Granted 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

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

Abstract

PURPOSE:To realize a miniature structure for a detecting prism and a photodetector, by newly adding a concave lens and a convex lens to an optical system of a device that detects a shift of focus by means of the critical angle of the prism. CONSTITUTION:A collimator lens 20 is provided between a polarized prism 3 and an objective lens 5, and the divergent flux of light radiated from a light source 1 and reflected by the prism 3 is turned into a parallel flux of light to be made incident to the lens 5. The light reflected from a disk 6 is condensed through the lens 5 and turned into a parallel flux of light when the lens is in focus and sent back to the lens 20 and then converged. This flux of light transmits through the prism 3 and is turned again into a parallel flux of light through a concave lens 21. The diameter of the flux of light can be extremely reduced in comparison with the diameter of the flux of light sent from the lens 5. Thus a detecting prism 10 and a photodetector 12 can be miniaturized.
JP10210680A 1980-07-25 1980-07-25 Focus detector Granted JPS5727444A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10210680A JPS5727444A (en) 1980-07-25 1980-07-25 Focus detector

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10210680A JPS5727444A (en) 1980-07-25 1980-07-25 Focus detector

Publications (2)

Publication Number Publication Date
JPS5727444A true JPS5727444A (en) 1982-02-13
JPH0219537B2 JPH0219537B2 (en) 1990-05-02

Family

ID=14318542

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10210680A Granted JPS5727444A (en) 1980-07-25 1980-07-25 Focus detector

Country Status (1)

Country Link
JP (1) JPS5727444A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5950036U (en) * 1982-09-24 1984-04-03 フオスタ−電機株式会社 Optical information reading device
JPH04103626U (en) * 1991-02-14 1992-09-07 株式会社トーキン isolation transformer
JPH0655224U (en) * 1991-02-15 1994-07-26 株式会社トーキン Isolation transformer

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS544105A (en) * 1977-06-06 1979-01-12 Mca Disco Vision Lens focusing device

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS544105A (en) * 1977-06-06 1979-01-12 Mca Disco Vision Lens focusing device

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5950036U (en) * 1982-09-24 1984-04-03 フオスタ−電機株式会社 Optical information reading device
JPH04103626U (en) * 1991-02-14 1992-09-07 株式会社トーキン isolation transformer
JPH0655224U (en) * 1991-02-15 1994-07-26 株式会社トーキン Isolation transformer

Also Published As

Publication number Publication date
JPH0219537B2 (en) 1990-05-02

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