JPS5784411A - Focus detecting method - Google Patents

Focus detecting method

Info

Publication number
JPS5784411A
JPS5784411A JP15990980A JP15990980A JPS5784411A JP S5784411 A JPS5784411 A JP S5784411A JP 15990980 A JP15990980 A JP 15990980A JP 15990980 A JP15990980 A JP 15990980A JP S5784411 A JPS5784411 A JP S5784411A
Authority
JP
Japan
Prior art keywords
focus
image
contrast
diffraction grating
pickup element
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
JP15990980A
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 JP15990980A priority Critical patent/JPS5784411A/en
Publication of JPS5784411A publication Critical patent/JPS5784411A/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 exactly detect a focus with high accuracy, by using an image pickup element tightly provided on the reverse side of a diffraction grating, and detecting a focused state by means of contrast measurement. CONSTITUTION:An image of an object is formed on the surface of a diffraction grating 2 by an objective lens 1. An image pickup element 3 is provided tightly on the reverse side of the diffraction grating 2. In case of dissidence of a focus, a multiimage is formed, therefore, contrast of the image drops and as the image approaches coincidence of a focus, the contrast rises and becomes maximum in a focused state. Accordingly, the focus is detected by measuring the contrast of an image in case when the focus is moving, by the image pickup element 3 and a detecting circuit 5.
JP15990980A 1980-11-13 1980-11-13 Focus detecting method Pending JPS5784411A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP15990980A JPS5784411A (en) 1980-11-13 1980-11-13 Focus detecting method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP15990980A JPS5784411A (en) 1980-11-13 1980-11-13 Focus detecting method

Publications (1)

Publication Number Publication Date
JPS5784411A true JPS5784411A (en) 1982-05-26

Family

ID=15703810

Family Applications (1)

Application Number Title Priority Date Filing Date
JP15990980A Pending JPS5784411A (en) 1980-11-13 1980-11-13 Focus detecting method

Country Status (1)

Country Link
JP (1) JPS5784411A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9488500B2 (en) 2011-04-18 2016-11-08 Mitsubishi Electric Corporation Position measurment apparatus for measuring position of mobile object on the basis of refelected wave

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9488500B2 (en) 2011-04-18 2016-11-08 Mitsubishi Electric Corporation Position measurment apparatus for measuring position of mobile object on the basis of refelected wave

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