Patent US1627145A successfully refreshed from Google Patents.
Patent US5089843A successfully refreshed from Google Patents.
US5089843A
Expired / Lapsed
US
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Auto focus device with predictive focussing
Assignee: Canon Inc
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Filing: 1991-03-20
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Granted: 1992-02-18
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Expires: 2011-03-20
Abstract
Abstract An auto focus device for predicting the position of a moving objerct after a predetermined time on the basis of past autofocus operations and driving the lens to focus on the predicted position. The predetermined time being calculated based on the discrimination of the direction of movement of the object. The predicting calculations place the lens in a closer near state rather than making the lens in focus to the moving object.
Inventors
- 👤 Masaki Higashihara
- 👤 Ichiro Ohnuki
- 👤 Akira Akashi
- 👤 Terutake Kadohara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:22
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/36
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
95 words
An autofocus device, comprising: (a) a focus detection circuit for repeatedly performing a focus detection operation to an object; (b) a calculation circuit for calculating an image plane position which is a predetermined distance closer on a near force side than a foreseen image plane for the object after expiration of a predetermined time based on a past focus detection operation, and for determining a lens driving amount corresponding to the calculated image plane position; and (c) a lens driving circuit for driving a lens by the lens driving amount obtained by said calculation circuit.
Claim 2
Dependent Claim
95 words
An autofocus device, comprising: (a) a focus detection circuit for repeatedly performing a focus detection operation to an object; (b) a calculation circuit for calculating an image plane position which is a predetermined distance closer on a near force side than a foreseen image plane for the object after expiration of a predetermined time based on a past focus detection operation, and for determining a lens driving amount corresponding to the calculated image plane position; and (c) a lens driving circuit for driving a lens by the lens driving amount obtained by said calculation circuit.
Claim 3
Dependent Claim
45 words
An autofocus device according to claim 1, wherein said focus detection circuit detects a defocus amount, and wherein data which is calculated by adding a predetermined amount to the detected defocus amount is input to said calculation circuit as a result of the focus detection.
Claim 4
Dependent Claim
70 words
An autofocus detection circuit according to claim 1, wherein said calculation circuit adds a predetermined amount to a lens driving amount which corresponds to the foreseen image plane position for the object after expiration of the predetermined time on the basis of the past focus detection operation obtained by said focus detection circuit, and outputs an added result as the lens driving amount corresponding to the calculated image plane position.
Claim 5
Dependent Claim
126 words
An autofocus device, comprising: (a) a focus detection circuit for repeatedly performing a focus-detection operation to an object; (b) a discrimination circuit for discriminating a direction of movement of the object; (c) a calculation circuit for receiving (a) results of a past focus detection operation detected by said focus detection circuit and (b) a predetermined time as factors for calculating a control amount related to an imaging plane position of the object after expiration of the predetermined time; (d) an adjusting circuit for adjusting said predetermined time input to said calculation circuit based on the direction of movement of the object discriminated by said discrimination circuit; and (e) a lens driving circuit for driving a lens based on the control amount obtained by said calculation circuit.
Claim 6
Dependent Claim
126 words
An autofocus device, comprising: (a) a focus detection circuit for repeatedly performing a focus-detection operation to an object; (b) a discrimination circuit for discriminating a direction of movement of the object; (c) a calculation circuit for receiving (a) results of a past focus detection operation detected by said focus detection circuit and (b) a predetermined time as factors for calculating a control amount related to an imaging plane position of the object after expiration of the predetermined time; (d) an adjusting circuit for adjusting said predetermined time input to said calculation circuit based on the direction of movement of the object discriminated by said discrimination circuit; and (e) a lens driving circuit for driving a lens based on the control amount obtained by said calculation circuit.
Claim 7
Dependent Claim
98 words
A camera having an autofocus device, comprising: (a) a focus detection circuit for repeatedly performing a focus detection operation to an object; (b) a calculation circuit for calculating an image plane position which is a predetermined distance closer on a near focus side than a foreseen image plane for the object after expiration of a predetermined time based on a past focus detection operation, and for determining a lens driving amount corresponding to said calculated image plane position; and (c) a lens driving circuit for driving a lens by the lens driving amount obtained by said calculation circuit.
Claim 8
Dependent Claim
98 words
A camera having an autofocus device, comprising: (a) a focus detection circuit for repeatedly performing a focus detection operation to an object; (b) a calculation circuit for calculating an image plane position which is a predetermined distance closer on a near focus side than a foreseen image plane for the object after expiration of a predetermined time based on a past focus detection operation, and for determining a lens driving amount corresponding to said calculated image plane position; and (c) a lens driving circuit for driving a lens by the lens driving amount obtained by said calculation circuit.
Claim 9
Dependent Claim
44 words
A camera according to claim 5, wherein said focus detection circuit detects a defocus amount, and wherein data which is calculated by adding a predetermined amount to the detected defocus amount is input to said calculation circuit as a result of the focus detection.
Claim 10
Dependent Claim
66 words
A camera according to claim 5, wherein said calculation circuit adds a predetermined amount to a lens driving amount which corresponds to the foreseen image plane position for the object after expiration of the predetermined time based on the past focus detection operation obtained by said focus detection circuit, and outputs an added result as the lens driving amount corresponding to the calculated image plane position.
Claim 11
Dependent Claim
130 words
A camera having an autofocus device, comprising: (a) a focus detection circuit for repeatedly performing a focus detection operation to an object; (b) a discrimination circuit for discriminating a direction of movement of the object; (c) a calculation circuit for receiving (a) results of a past focus detection operation detected by said focus detection circuit and (b) a predetermined time as factors for calculating a control amount related to an imaging plane position of the object after expiration of the predetermined time; (d) an adjusting circuit for adjusting said predetermined time input to said calculation circuit based on the direction of movement of the object discriminated by said discrimination circuit; and (e) a lens driving circuit for driving a lens based on the control amount obtained by said calculation circuit.
Claim 12
Dependent Claim
130 words
A camera having an autofocus device, comprising: (a) a focus detection circuit for repeatedly performing a focus detection operation to an object; (b) a discrimination circuit for discriminating a direction of movement of the object; (c) a calculation circuit for receiving (a) results of a past focus detection operation detected by said focus detection circuit and (b) a predetermined time as factors for calculating a control amount related to an imaging plane position of the object after expiration of the predetermined time; (d) an adjusting circuit for adjusting said predetermined time input to said calculation circuit based on the direction of movement of the object discriminated by said discrimination circuit; and (e) a lens driving circuit for driving a lens based on the control amount obtained by said calculation circuit.
Claim 13
Dependent Claim
41 words
An autofocus device according to claim 1, wherein said calculation circuit determines the foreseen image plane by using a higher order function, coefficients of which are determined by using focus data and time data obtained in the past focus detection operation.
Claim 14
Dependent Claim
41 words
An autofocus device according to claim 1, wherein said calculation circuit determines the lens driving amount by using a higher order function, coefficients of which are determined by using focus data and time data obtained in the past focus detection operation.
Claim 15
Dependent Claim
41 words
An autofocus device according to claim 2, wherein said calculation circuit determines the foreseen image plane by using a higher order function, coefficients of which are determined by using focus data and time data obtained in the past focus detection operation.
Claim 16
Dependent Claim
41 words
An autofocus device according to claim 3, wherein said calculation circuit determines the foreseen image plane by using a higher order function, coefficients of which are determined by using focus data and time data obtained in the past focus detection operation.
Claim 17
Dependent Claim
40 words
A camera according to claim 5, wherein said calculation circuit determines the foreseen image plane by using a higher order function, coefficients of which are determined by using focus data and time data obtained in the past focus detection operation.
Claim 18
Dependent Claim
40 words
A camera according to claim 7, wherein said calculation circuit determines the foreseen image plane by using a higher order function, coefficients of which are determined by using focus data and time data obtained in the past focus detection operation.
Claim 19
Dependent Claim
39 words
A camera according to claim 8, wherein said calculation circuit determines the control amount by using a higher order function, coefficients of which are determined by using focus data and time data obtained in the past focus detection operation.
References Cited (Backward Citations)
US4783677A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-02-17 | 1995-08-19 | 1996-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-02-17 | 1999-08-19 | 2000-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-02-17 | 2003-08-19 | 2004-02-18 | $7700.00 | Window Closed / Lapsed |