Patent US5138356A successfully refreshed from Google Patents.
US5138356A
Expired / Lapsed
US
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Automatic focus adjusting apparatus of a camera
Assignee: Minolta Co Ltd
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Filing: 1991-01-29
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Granted: 1992-08-11
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Expires: 2011-01-29
Abstract
Abstract An automatic focus adjusting apparatus of a camera calculates amount of defocus of an object, and repeatedly calculates the speed of the image plane of the object based on the amount of defocus. When releasing operation of the camera is started, image plane speed of the object at the time of exposure is estimated by using a secondary curve based on the speed of the image plane, and the lens is driven based on the data thereof. Since the image plane speed of the object is estimated by using the secondary curve equation, correction of the amount of defocus can be accurately done regardless of the speed of movement of the object.
Inventors
- 👤 Kimihiko Nakamura
- 👤 Yoshinori Ueyama
- 👤 Masataka Hamada
- 👤 Kenji Ishibashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 11:16
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/36
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
101 words
An automatic focus adjusting apparatus of a camera, comprising: defocus amount calculating means for calculating amount of defocus of an object; image plane speed calculating means for calculating repeatedly image plane speed of said object based on the amount of defocus calculated by said defocus amount calculating means; image plane speed estimating means for estimating image plane speed of said object at the time of exposure by using an approximation function of high degree, based on said image plane speeds at the start of releasing; and lens position calculating means for calculating lens position based on said estimated image plane speed.
Claim 2
Dependent Claim
101 words
An automatic focus adjusting apparatus of a camera, comprising: defocus amount calculating means for calculating amount of defocus of an object; image plane speed calculating means for calculating repeatedly image plane speed of said object based on the amount of defocus calculated by said defocus amount calculating means; image plane speed estimating means for estimating image plane speed of said object at the time of exposure by using an approximation function of high degree, based on said image plane speeds at the start of releasing; and lens position calculating means for calculating lens position based on said estimated image plane speed.
Claim 3
Dependent Claim
39 words
An automatic focus adjusting apparatus of a camera according to claim 1, wherein said image plane speed estimating means includes means for calculating mean value of a plurality of image plane speeds, for estimation based on the mean value.
Claim 4
Dependent Claim
28 words
An automatic focus adjusting apparatus of a camera according to claim 2, wherein said mean value calculating means calculates the mean value by weighting new image plane speed.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-08-11 | 1996-02-10 | 1996-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-11 | 2000-02-10 | 2000-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-11 | 2004-02-10 | 2004-08-11 | $7700.00 | Window Closed / Lapsed |