JPS5767902A - Focus detecting method - Google Patents

Focus detecting method

Info

Publication number
JPS5767902A
JPS5767902A JP14337380A JP14337380A JPS5767902A JP S5767902 A JPS5767902 A JP S5767902A JP 14337380 A JP14337380 A JP 14337380A JP 14337380 A JP14337380 A JP 14337380A JP S5767902 A JPS5767902 A JP S5767902A
Authority
JP
Japan
Prior art keywords
image
contrast
focus
photodetector
grating
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
JP14337380A
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 JP14337380A priority Critical patent/JPS5767902A/en
Publication of JPS5767902A publication Critical patent/JPS5767902A/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
    • G02B7/34—Systems for automatic generation of focusing signals using different areas in a pupil plane

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Automatic Focus Adjustment (AREA)

Abstract

PURPOSE:To detect an in-focus state, by measuring the contrast of an image sent from the output of a photodetector and detecting electrically that the contrast of the image becomes maximum. CONSTITUTION:An image of a subject is formed on the surface of a diffraction grating 2 by an objective lens 1. The image of the grating 2 is formed through an image forming lens 4 on a photodetector 3 which is set at the back of the grating 2. Thus only the light that forms a part of the image is irradiated on the receiving surface of the photodetector 3. When the image contrast is measured while the focus is shifting, the contrast becomes higher toward an in-focus state. And the contrast becomes highest in the in-focus state and increases when the image gets out of focus. Accordingly the in-focus moment can be detected by detecting the maximum contrast of image.
JP14337380A 1980-10-14 1980-10-14 Focus detecting method Pending JPS5767902A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP14337380A JPS5767902A (en) 1980-10-14 1980-10-14 Focus detecting method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP14337380A JPS5767902A (en) 1980-10-14 1980-10-14 Focus detecting method

Publications (1)

Publication Number Publication Date
JPS5767902A true JPS5767902A (en) 1982-04-24

Family

ID=15337270

Family Applications (1)

Application Number Title Priority Date Filing Date
JP14337380A Pending JPS5767902A (en) 1980-10-14 1980-10-14 Focus detecting method

Country Status (1)

Country Link
JP (1) JPS5767902A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60131511A (en) * 1983-12-20 1985-07-13 Matsushita Electric Ind Co Ltd Automatic focus detector

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60131511A (en) * 1983-12-20 1985-07-13 Matsushita Electric Ind Co Ltd Automatic focus detector

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