US4969003A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Autofocus device
Assignee: Canon Inc
•
Filing: 1989-05-05
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Granted: 1990-11-06
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Expires: 2009-05-05
Abstract
Abstract An auto-focus device or a camera equipped with such a device includes a focus detecting circuit for repeatedly detecting focus, in which an image forming optical system is driven on the basis of the focusing quantity detected by the focus detecting circuit. A speed computing circuit is provided for computing a speed of movement of an image plane corresponding to movement of the object on the basis of past autofocusing operation data. A drive data computing circuit is provided for predictive-computing data relating to a drive position of the image forming optical system, considering the movement of the object, on the basis of the past autofocusing operation data. A speed control circuit is provided for controlling a driving speed of the image forming optical system on the basis of the speed obtained by the speed computing circuit. A drive circuit is provided for driving the image forming optical system in one of a first mode in which a drive position of the optical system is controlled in accordance with data obtained by the drive data computing circuit without actuating the speed control circuit, and a second mode in which a driving speed of the optical system is controlled by the speed control circuit without actuating the drive position of the optical system using the drive data computing circuit. Finally, a selection circuit is provided for selecting between the first and second modes.
Inventors
- 👤 Ichiro Ohnuki
- 👤 Akira Akashi
- 👤 Terutake Kadohara
- 👤 Masaki Higashihara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:52
CPC Classifications
G; G02; G02B; G02B7/00; G02B7/28; G02B7/36
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
179 words
An autofocus device, of a camera equipped with the autofocus device, having a focus detecting circuit for repeatedly detecting focus, in which an image forming optical system is driven on the basis of a focusing quantity detected by the focus detecting circuit, comprising: an optical system position controlling circuit in which data based on the focusing quantity detected by the focus detecting circuit are set to move the optical system to a position corresponding to the set data; a speed computing circuit for computing a speed of movement of an image plane corresponding to movement of an object on the basis of a past autofocusing operation data; a speed control circuit for controlling a driving speed of the image forming optical system on the basis of the speed obtained by said speed computing circuit; and mode selection means for selecting a first mode for driving the optical system using said position controlling circuit without actuating said speed control circuit, and a second mode for driving the optical system using said speed control circuit without actuating said position controlling circuit.
Claim 2
Dependent Claim
179 words
An autofocus device, of a camera equipped with the autofocus device, having a focus detecting circuit for repeatedly detecting focus, in which an image forming optical system is driven on the basis of a focusing quantity detected by the focus detecting circuit, comprising: an optical system position controlling circuit in which data based on the focusing quantity detected by the focus detecting circuit are set to move the optical system to a position corresponding to the set data; a speed computing circuit for computing a speed of movement of an image plane corresponding to movement of an object on the basis of a past autofocusing operation data; a speed control circuit for controlling a driving speed of the image forming optical system on the basis of the speed obtained by said speed computing circuit; and mode selection means for selecting a first mode for driving the optical system using said position controlling circuit without actuating said speed control circuit, and a second mode for driving the optical system using said speed control circuit without actuating said position controlling circuit.
Claim 3
Dependent Claim
57 words
An autofocus device or a camera according to claim 1, wherein said speed computing circuit computes data relating to a movement position of the image plane on the basis of the past autofocusing operation data and computes a speed of movement of the image plane from said data relating to a movement position of the image plane.
Claim 4
Dependent Claim
36 words
An autofocus device or a camera according to claim 1, wherein said data relating to a movement position of the image plane is a function indicative of displacement of a movement position of the image plane.
Claim 5
Dependent Claim
25 words
An autofocus device or a camera according to claim 1, wherein said autofocusing operation data is the focusing quantity detected by the focus detecting circuit.
Claim 6
Dependent Claim
32 words
An autofocus device or a camera according to claim 1, wherein said speed computing circuit computes a speed of movement of the image plane each time the focus detecting circuit detects focus.
Claim 7
Dependent Claim
236 words
An autofocus device, or a camera equipped with the autofocus device, having a focus detecting circuit for repeatedly detecting focus, in which an image forming optical system is driven on the basis of a focusing quantity detected by the focus detecting circuit, comprising: (a) a speed computing circuit for computing a speed of movement of an image plane corresponding to movement of an object on the basis of past autofocusing operation data; (b) a drive data computing circuit for predictive-computing data relating to a drive position of the image forming optical system in consideration of movement of the object on the basis of the past autofocusing operation data; (c) a speed control circuit for controlling a driving speed of the image forming optical system on the basis of the speed obtained by said speed computing circuit; (d) a drive circuit for driving the image forming optical system, said drive circuit operating in one of a first mode in which a drive position of the optical system is controlled in accordance with the data obtained by said drive data computing circuit without actuating said speed control circuit, and a second mode in which a driving speed of the optical system is controlled by said speed control circuit without actuating the drive position of the optical system using said drive data computing circuit; and (e) a selection circuit for selecting one of said first and said second modes.
Claim 8
Dependent Claim
236 words
An autofocus device, or a camera equipped with the autofocus device, having a focus detecting circuit for repeatedly detecting focus, in which an image forming optical system is driven on the basis of a focusing quantity detected by the focus detecting circuit, comprising: (a) a speed computing circuit for computing a speed of movement of an image plane corresponding to movement of an object on the basis of past autofocusing operation data; (b) a drive data computing circuit for predictive-computing data relating to a drive position of the image forming optical system in consideration of movement of the object on the basis of the past autofocusing operation data; (c) a speed control circuit for controlling a driving speed of the image forming optical system on the basis of the speed obtained by said speed computing circuit; (d) a drive circuit for driving the image forming optical system, said drive circuit operating in one of a first mode in which a drive position of the optical system is controlled in accordance with the data obtained by said drive data computing circuit without actuating said speed control circuit, and a second mode in which a driving speed of the optical system is controlled by said speed control circuit without actuating the drive position of the optical system using said drive data computing circuit; and (e) a selection circuit for selecting one of said first and said second modes.
Claim 9
Dependent Claim
57 words
An autofocus device or a camera according to claim 6, wherein said speed computing circuit computes data relating to a movement position of the image plane on the basis of the past autofocusing operation data and computes a speed of movement of the image plane from said data relating to a movement position of the image plane.
Claim 10
Dependent Claim
36 words
An autofocus device or a camera according to claim 6, wherein said data relating to a movement position of the image plane is a function indicative of displacement of a movement position of the image plane.
Claim 11
Dependent Claim
25 words
An autofocus device or a camera according to claim 6, wherein said autofocusing operation data is the focusing quantity detected by said focus detecting circuit.
References Cited (Backward Citations)
US4816856A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-11-05 | 1994-05-07 | 1994-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-11-05 | 1998-05-07 | 1998-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-11-05 | 2002-05-07 | 2002-11-06 | $7700.00 | Window Closed / Lapsed |