JPS648771A - Automatic focus circuit - Google Patents
Automatic focus circuitInfo
- 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
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.
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)
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)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5643965U (en) * | 1979-09-13 | 1981-04-21 |
-
1987
- 1987-06-30 JP JP62164382A patent/JPH0759048B2/en not_active Expired - Lifetime
Patent Citations (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5643965U (en) * | 1979-09-13 | 1981-04-21 |
Cited By (4)
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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Legal Events
Date | Code | Title | Description |
---|---|---|---|
EXPY | Cancellation because of completion of term | ||
FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080621 Year of fee payment: 13 |