JPS648771A - Automatic focus circuit - Google Patents

Automatic focus circuit

Info

Publication number
JPS648771A
JPS648771A JP62164382A JP16438287A JPS648771A JP S648771 A JPS648771 A JP S648771A JP 62164382 A JP62164382 A JP 62164382A JP 16438287 A JP16438287 A JP 16438287A JP S648771 A JPS648771 A JP S648771A
Authority
JP
Japan
Prior art keywords
circuit
focus evaluation
evaluation value
generating circuit
focus
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
JP62164382A
Other languages
Japanese (ja)
Other versions
JPH0759048B2 (en
Inventor
Masaru Hidaka
Hiroshi Murashima
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.)
Sanyo Electric Co Ltd
Original Assignee
Sanyo Electric 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
Application filed by Sanyo Electric Co Ltd filed Critical Sanyo Electric Co Ltd
Priority to JP62164382A priority Critical patent/JPH0759048B2/en
Priority to US07/211,434 priority patent/US4922346A/en
Priority to CA000570629A priority patent/CA1289236C/en
Priority to KR8807896A priority patent/KR930004641B1/en
Priority to AU18535/88A priority patent/AU596018B2/en
Priority to EP88110492A priority patent/EP0297587B1/en
Priority to ES88110492T priority patent/ES2063746T3/en
Priority to DE3851383T priority patent/DE3851383T2/en
Publication of JPS648771A publication Critical patent/JPS648771A/en
Priority to AU48920/90A priority patent/AU609346B2/en
Publication of JPH0759048B2 publication Critical patent/JPH0759048B2/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Abstract

PURPOSE:To attain stable automatic focusing by comparing a relative value of a focus evaluation with a prescribed value and applying focusing through the result of comparison. CONSTITUTION:A 1st filter circuit 15, a switch circuit 17 and an integration circuit 18 constitute a 1st focus evaluation value generating circuit and a 2nd filter circuit 16, the circuit 17 and the circuit 18 constitute a 2nd focus evaluation generating circuit. The present focus evaluation value is compared with a content of a memory 11 by a comparator 12. When the input to a focus motor control circuit 10 passes through the 1st focus evaluation value generating circuit, a switch circuit 19 is thrown. When the input to the circuit 10 passes through the 2nd focus evaluation value generating circuit, the circuit 19 is maintained at the present state. As a result, if the focus evaluation value exceeds a threshold value, the focusing is restarted by using an output of the 2nd focus evaluation value generating circuit having always slow characteristic in the curve of the focus evaluation value.
JP62164382A 1987-06-30 1987-06-30 Auto focus device Expired - Lifetime JPH0759048B2 (en)

Priority Applications (9)

Application Number Priority Date Filing Date Title
JP62164382A JPH0759048B2 (en) 1987-06-30 1987-06-30 Auto focus device
US07/211,434 US4922346A (en) 1987-06-30 1988-06-24 Automatic focusing apparatus having a variable focusing speed and particularly suited for use with interlaced scanning
CA000570629A CA1289236C (en) 1987-06-30 1988-06-28 Automatic focusing apparatus having a variable focusing speed and particularly suited for use with interlaced scanning
KR8807896A KR930004641B1 (en) 1987-06-30 1988-06-29 Auto focus apparatus
AU18535/88A AU596018B2 (en) 1987-06-30 1988-06-29 Automatic focusing apparatus for automatically matching focus in response to video signal
EP88110492A EP0297587B1 (en) 1987-06-30 1988-06-30 Automatic focusing apparatus for automatically matching focus in response to video signal
ES88110492T ES2063746T3 (en) 1987-06-30 1988-06-30 AUTOMATIC LOCATION CIRCUIT TO AUTOMATICALLY ASSOCIATE THE LOCATION ACCORDING TO THE VIDEO SIGNAL.
DE3851383T DE3851383T2 (en) 1987-06-30 1988-06-30 Automatic focusing circuit for automatic focus adjustment depending on video signals.
AU48920/90A AU609346B2 (en) 1987-06-30 1990-01-30 Automatic focusing apparatus for automatically matching focus in response to video signal

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP62164382A JPH0759048B2 (en) 1987-06-30 1987-06-30 Auto focus device

Publications (2)

Publication Number Publication Date
JPS648771A true JPS648771A (en) 1989-01-12
JPH0759048B2 JPH0759048B2 (en) 1995-06-21

Family

ID=15792066

Family Applications (1)

Application Number Title Priority Date Filing Date
JP62164382A Expired - Lifetime JPH0759048B2 (en) 1987-06-30 1987-06-30 Auto focus device

Country Status (1)

Country Link
JP (1) JPH0759048B2 (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0397379A (en) * 1989-09-10 1991-04-23 Canon Inc Automatic focus adjustor
JPH03107282A (en) * 1989-09-20 1991-05-07 Canon Inc Automatic focusing device
JPH03285467A (en) * 1990-03-30 1991-12-16 Sharp Corp Automatic focusing device
JPH0414964A (en) * 1990-05-08 1992-01-20 Sharp Corp Automatic focus device

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5643965U (en) * 1979-09-13 1981-04-21

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5643965U (en) * 1979-09-13 1981-04-21

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH0397379A (en) * 1989-09-10 1991-04-23 Canon Inc Automatic focus adjustor
JPH03107282A (en) * 1989-09-20 1991-05-07 Canon Inc Automatic focusing device
JPH03285467A (en) * 1990-03-30 1991-12-16 Sharp Corp Automatic focusing device
JPH0414964A (en) * 1990-05-08 1992-01-20 Sharp Corp Automatic focus device

Also Published As

Publication number Publication date
JPH0759048B2 (en) 1995-06-21

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