JPS576815A - Focus detecting method - Google Patents

Focus detecting method

Info

Publication number
JPS576815A
JPS576815A JP7984480A JP7984480A JPS576815A JP S576815 A JPS576815 A JP S576815A JP 7984480 A JP7984480 A JP 7984480A JP 7984480 A JP7984480 A JP 7984480A JP S576815 A JPS576815 A JP S576815A
Authority
JP
Japan
Prior art keywords
elements
servomotor
inputted
rates
outputs
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
JP7984480A
Other languages
Japanese (ja)
Inventor
Toshihiro Kondo
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.)
Nippon Seimitsu Kogyo KK
Original Assignee
Nippon Seimitsu Kogyo KK
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 Nippon Seimitsu Kogyo KK filed Critical Nippon Seimitsu Kogyo KK
Priority to JP7984480A priority Critical patent/JPS576815A/en
Publication of JPS576815A publication Critical patent/JPS576815A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B7/00—Mountings, adjusting means, or light-tight connections, for optical elements
    • G02B7/28—Systems for automatic generation of focusing signals
    • G02B7/36—Systems for automatic generation of focusing signals using image sharpness techniques, e.g. image processing techniques for generating autofocus signals

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Automatic Focus Adjustment (AREA)

Abstract

PURPOSE:To electrically detect focus by the simple constitution wherein a photodetector consisting of at least two pieces of photoelectric elements adjoining by way of a boundary line extending in the direction intersecting with the refraction direction of a refractive optical element is provided on the rear surface of the refractive optical element in close contact therewith. CONSTITUTION:An objective lens 51 forms images on a diffraction grating 52, and a photodetector 53 consisting of two adjacent photoelectric elements 53a, 53b is provided on the rear surface of this grating 52 in close contact therewith. The outputs of the elements 53a, 53b are inputted to a detecting circuit 54, which detects the difference in the rates of change in the outputs of both elements with the movements of focus. The output of the circuit 54 is inputted to a servomotor 57 driving a pinion 56a meshed with a rack 55a provided to an arm 55 holding the lens 51, and when the difference in said rates of change goes to zero, the servomotor 57 is stopped, thereby stopping the objective lens 51.
JP7984480A 1980-06-13 1980-06-13 Focus detecting method Pending JPS576815A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP7984480A JPS576815A (en) 1980-06-13 1980-06-13 Focus detecting method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP7984480A JPS576815A (en) 1980-06-13 1980-06-13 Focus detecting method

Publications (1)

Publication Number Publication Date
JPS576815A true JPS576815A (en) 1982-01-13

Family

ID=13701505

Family Applications (1)

Application Number Title Priority Date Filing Date
JP7984480A Pending JPS576815A (en) 1980-06-13 1980-06-13 Focus detecting method

Country Status (1)

Country Link
JP (1) JPS576815A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0745979A2 (en) * 1995-05-31 1996-12-04 Daewoo Electronics Co., Ltd Optical pickup apparatus having objective lens positioning system

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0745979A2 (en) * 1995-05-31 1996-12-04 Daewoo Electronics Co., Ltd Optical pickup apparatus having objective lens positioning system
EP0745979A3 (en) * 1995-05-31 1997-01-22 Daewoo Electronics Co., Ltd Optical pickup apparatus having objective lens positioning system

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