JPS6317413A - Automatic focusing device - Google Patents

Automatic focusing device

Info

Publication number
JPS6317413A
JPS6317413A JP61161053A JP16105386A JPS6317413A JP S6317413 A JPS6317413 A JP S6317413A JP 61161053 A JP61161053 A JP 61161053A JP 16105386 A JP16105386 A JP 16105386A JP S6317413 A JPS6317413 A JP S6317413A
Authority
JP
Japan
Prior art keywords
image
circuit
sharpness
focusing
pickup optical
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
JP61161053A
Other languages
Japanese (ja)
Other versions
JPH083579B2 (en
Inventor
Takako Watanabe
Takeshi Baba
Yukichi Niwa
Original Assignee
Canon Inc
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 Canon Inc filed Critical Canon Inc
Priority to JP61161053A priority Critical patent/JPH083579B2/en
Priority claimed from US06/922,740 external-priority patent/US4804831A/en
Publication of JPS6317413A publication Critical patent/JPS6317413A/en
Priority claimed from US07/497,075 external-priority patent/US5055665A/en
Publication of JPH083579B2 publication Critical patent/JPH083579B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Abstract

PURPOSE: To perform focusing operation at a high speed by shifting an image pickup optical system in a specific direction from where the sharpness of an object image is maximum and stopping the system, and then determining the driving direction of an image pickup optical system based on information on the detected sharpness and the direction.
CONSTITUTION: An image signal I(t) obtained from an image pickup element 1 is inputted to a differentiation circuit 2 and an absolute value circuit 3 to calculates a signal dI/(dt). The signal dI/(dt) is supplied to logarithmic circuits 7 and 5 through a delay circuit 6 and a ΔI calculating circuit 4 and both obtained logarithmic values are supplied to a subtracter circuit 8. The output signal P(t) of the circuit 8 is compared with a previously given threshold value P0 and when the counted value of a counter 11 exceeds a specific value, focusing is decided. The image pickup optical system is stopped after shifted in the specific direction from the position where the sharpness of the object image is maximum within this focusing range, and the driving direction of the image pickup optical system is determined based on the information on the detected sharpness and its direction after the stop. Thus, the focusing is carried out at a high speed.
COPYRIGHT: (C)1988,JPO&Japio
JP61161053A 1986-07-09 1986-07-09 Automatic focusing device Expired - Fee Related JPH083579B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP61161053A JPH083579B2 (en) 1986-07-09 1986-07-09 Automatic focusing device

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
JP61161053A JPH083579B2 (en) 1986-07-09 1986-07-09 Automatic focusing device
US06/922,740 US4804831A (en) 1985-10-30 1986-10-24 Focus detecting apparatus independent of object image contrast
DE3636951A DE3636951C2 (en) 1985-10-30 1986-10-30
US07/497,075 US5055665A (en) 1985-10-30 1990-03-21 Focus detecting apparatus jointly employing outputs of plural diverse detectors

Publications (2)

Publication Number Publication Date
JPS6317413A true JPS6317413A (en) 1988-01-25
JPH083579B2 JPH083579B2 (en) 1996-01-17

Family

ID=15727712

Family Applications (1)

Application Number Title Priority Date Filing Date
JP61161053A Expired - Fee Related JPH083579B2 (en) 1986-07-09 1986-07-09 Automatic focusing device

Country Status (1)

Country Link
JP (1) JPH083579B2 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0829667A (en) * 1994-07-18 1996-02-02 Fuji Photo Optical Co Ltd Automatic focusing method
JP2016028294A (en) * 2010-05-26 2016-02-25 ナム タイ，ヒョク Autofocus control method
JP2018045102A (en) * 2016-09-14 2018-03-22 キヤノン株式会社 Focus adjustment device and imaging apparatus

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5114323A (en) * 1974-07-26 1976-02-04 Minolta Camera Kk
JPS5651164A (en) * 1979-10-03 1981-05-08 Hitachi Ltd Automatic focusing device

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5114323A (en) * 1974-07-26 1976-02-04 Minolta Camera Kk
JPS5651164A (en) * 1979-10-03 1981-05-08 Hitachi Ltd Automatic focusing device

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0829667A (en) * 1994-07-18 1996-02-02 Fuji Photo Optical Co Ltd Automatic focusing method
JP2016028294A (en) * 2010-05-26 2016-02-25 ナム タイ，ヒョク Autofocus control method
JP2018045102A (en) * 2016-09-14 2018-03-22 キヤノン株式会社 Focus adjustment device and imaging apparatus

Also Published As

Publication number Publication date
JPH083579B2 (en) 1996-01-17

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Legal Events

Date Code Title Description
LAPS Cancellation because of no payment of annual fees