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JPS54100704A - Focus adjusting device - Google Patents

Focus adjusting device

Info

Publication number
JPS54100704A
JPS54100704A JP610978A JP610978A JPS54100704A JP S54100704 A JPS54100704 A JP S54100704A JP 610978 A JP610978 A JP 610978A JP 610978 A JP610978 A JP 610978A JP S54100704 A JPS54100704 A JP S54100704A
Authority
JP
Japan
Prior art keywords
plane
lens
focal
video disc
optically transparent
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
JP610978A
Other languages
Japanese (ja)
Inventor
Naoto Mogi
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 JP610978A priority Critical patent/JPS54100704A/en
Publication of JPS54100704A publication Critical patent/JPS54100704A/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
    • G11B7/085—Disposition or mounting of heads or light sources relatively to record carriers with provision for moving the light beam into, or out of, its operative position or across tracks, otherwise than during the transducing operation, e.g. for adjustment or preliminary positioning or track change or selection
    • G11B7/08547—Arrangements for positioning the light beam only without moving the head, e.g. using static electro-optical elements

Landscapes

  • Mounting And Adjusting Of Optical Elements (AREA)
  • Optical Recording Or Reproduction (AREA)

Abstract

PURPOSE:To make the focus adjustment highly accurate by interposing an optically transparent element having a variable thickness between an optical lens and a focal plane of a video disc recording and reproducing apparatus. CONSTITUTION:A reading laser beam 1 is concentrated by an optical lens 2 to concentrate a focal point on a video disc plane 3. Optically transparent elements 4a and 4b, which are interposed between the lens 2 and the plane 3, are made slidable relative to each other so that their thicknesses in the direction of the optical axis are varied to shift the focal plane of the lens 2. As a result, in accordance with the vertical changes in the plane 3, the transparent element 4a is shifted so that the focal point can always be formed on the plane 3.
JP610978A 1978-01-25 1978-01-25 Focus adjusting device Pending JPS54100704A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP610978A JPS54100704A (en) 1978-01-25 1978-01-25 Focus adjusting device

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP610978A JPS54100704A (en) 1978-01-25 1978-01-25 Focus adjusting device

Publications (1)

Publication Number Publication Date
JPS54100704A true JPS54100704A (en) 1979-08-08

Family

ID=11629322

Family Applications (1)

Application Number Title Priority Date Filing Date
JP610978A Pending JPS54100704A (en) 1978-01-25 1978-01-25 Focus adjusting device

Country Status (1)

Country Link
JP (1) JPS54100704A (en)

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