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GB2003692A - A method of detecting the state of focus of an optical system - Google Patents

A method of detecting the state of focus of an optical system

Info

Publication number
GB2003692A
GB2003692A GB7834512A GB7834512A GB2003692A GB 2003692 A GB2003692 A GB 2003692A GB 7834512 A GB7834512 A GB 7834512A GB 7834512 A GB7834512 A GB 7834512A GB 2003692 A GB2003692 A GB 2003692A
Authority
GB
United Kingdom
Prior art keywords
focus
group
signal
switcher
photosensitive elements
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.)
Granted
Application number
GB7834512A
Other versions
GB2003692B (en
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.)
Olympus Corp
Original Assignee
Olympus Corp
Olympus Optical 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
Priority claimed from JP10471377A external-priority patent/JPS5439126A/en
Priority claimed from JP4586778A external-priority patent/JPS54138427A/en
Application filed by Olympus Corp, Olympus Optical Co Ltd filed Critical Olympus Corp
Publication of GB2003692A publication Critical patent/GB2003692A/en
Application granted granted Critical
Publication of GB2003692B publication Critical patent/GB2003692B/en
Expired 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)
  • Focusing (AREA)

Abstract

Focus detection is performed in two stages: (a) by a widely spaced group of photosensitive elements 20; (b) by a second closely spaced group of elements 21. Switcher 22 firstly selects group 20 and the illuminance signal providing contrast information therefrom is fed via A/D converter 23 to arithmetic circuit 24 where a summation calculation is carried out to determine the coarse focus condition. Next, switcher selects the signal from group 21 which, after computation in circuit 24 provides a sharply varying detection signal in the region of focus which is used as a fine measurement. Other signal processing arrangements are given, e.g., using a microcomputer. Various patterns of photosensitive elements are disclosed. <IMAGE>
GB7834512A 1977-09-02 1978-08-24 Method for detecting a focalisation or in-focussed-condition of an optical system Expired GB2003692B (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP10471377A JPS5439126A (en) 1977-09-02 1977-09-02 Automatic focusing method
JP4586778A JPS54138427A (en) 1978-04-20 1978-04-20 Focus detecting method

Publications (2)

Publication Number Publication Date
GB2003692A true GB2003692A (en) 1979-03-14
GB2003692B GB2003692B (en) 1982-08-11

Family

ID=26385961

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7834512A Expired GB2003692B (en) 1977-09-02 1978-08-24 Method for detecting a focalisation or in-focussed-condition of an optical system

Country Status (3)

Country Link
DE (1) DE2838121B2 (en)
FR (1) FR2402222A1 (en)
GB (1) GB2003692B (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4561749A (en) * 1983-02-02 1985-12-31 Nippon Kogaku K.K. Focus detection apparatus
US4618236A (en) * 1983-11-08 1986-10-21 Canon Kabushiki Kaisha Focus detecting apparatus
WO2002005005A1 (en) * 2000-07-10 2002-01-17 Zsp Geodätische Systeme Gmbh Autofocussing method for telescopes pertaining to surveying equipment

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5529878A (en) * 1978-08-24 1980-03-03 Asahi Optical Co Ltd Focus detector of camera
JPS5589819A (en) 1978-12-28 1980-07-07 Asahi Optical Co Ltd Focus detector of camera
DE2910875C2 (en) * 1979-03-20 1985-11-14 Kernforschungszentrum Karlsruhe Gmbh, 7500 Karlsruhe Auto-focus procedure
US4687914A (en) * 1983-04-01 1987-08-18 Canon Kabushiki Kaisha Distance measuring device comprising a two sectioned sensor, each section having a plurality of sensing areas

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4047187A (en) * 1974-04-01 1977-09-06 Canon Kabushiki Kaisha System for exposure measurement and/or focus detection by means of image senser
JPS5156627A (en) * 1974-11-13 1976-05-18 Canon Kk Butsutaizosenmeidokenshutsuhoshiki

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4561749A (en) * 1983-02-02 1985-12-31 Nippon Kogaku K.K. Focus detection apparatus
US4618236A (en) * 1983-11-08 1986-10-21 Canon Kabushiki Kaisha Focus detecting apparatus
WO2002005005A1 (en) * 2000-07-10 2002-01-17 Zsp Geodätische Systeme Gmbh Autofocussing method for telescopes pertaining to surveying equipment
US6927376B2 (en) 2000-07-10 2005-08-09 Trimble Jena Gmbh Autofocusing method for telescopes pertaining to surveying equipment

Also Published As

Publication number Publication date
DE2838121B2 (en) 1980-01-17
FR2402222B1 (en) 1983-05-27
FR2402222A1 (en) 1979-03-30
DE2838121A1 (en) 1979-03-22
DE2838121C3 (en) 1980-09-11
GB2003692B (en) 1982-08-11

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Legal Events

Date Code Title Description
PCNP Patent ceased through non-payment of renewal fee