JPS5767902A - Focus detecting method - Google Patents
Focus detecting methodInfo
- 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
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.
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)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS60131511A (en) * | 1983-12-20 | 1985-07-13 | Matsushita Electric Ind Co Ltd | Automatic focus detector |
-
1980
- 1980-10-14 JP JP14337380A patent/JPS5767902A/en active Pending
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS60131511A (en) * | 1983-12-20 | 1985-07-13 | Matsushita Electric Ind Co Ltd | Automatic focus detector |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JPS5548737A (en) | Photoelectrically focus detecting device mounted camera | |
JPS57161708A (en) | Focusing detector having variable visual field of detection | |
JPS5780546A (en) | Detecting device for foreign substance | |
JPS55166609A (en) | Method of focusing of optical system having lighting device | |
JPS52109954A (en) | Optical signal reader | |
JPS5428133A (en) | Optical path extension device with focus detection function | |
JPS5748703A (en) | Distance detector | |
JPS5767902A (en) | Focus detecting method | |
JPS5639555A (en) | Original discrimination method | |
JPS5665121A (en) | Distance measuring and photometric device of camera | |
JPS57150808A (en) | Focus detecting device | |
JPS5766411A (en) | Focus detecting method | |
JPS53105223A (en) | Optical system of distance detector for automatic focusing | |
JPS5726704A (en) | Measuring instrument for three-dimensional shape | |
JPS5461503A (en) | Detection of focal point | |
JPS649306A (en) | Detector for light transmitting fine pattern | |
JPS5784410A (en) | Focus detecting method | |
JPS57113311A (en) | Measuring device for surface coarseness of object | |
JPS56153307A (en) | Focusing detecting method | |
JPS5414232A (en) | Method of detecting focus position depending on chromatic aberration of lens | |
JPS5511606A (en) | Photoelectric conversion device | |
JPS55528A (en) | Focus detecting method | |
JPS546533A (en) | Detecting method of focusing positions by chromatic aberrations of lens | |
JPS5325431A (en) | Automati c focusing device | |
JPS55110228A (en) | Focus detector of camera |