US3678822A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Shutter mechanism control circuitry
Assignee: Minolta Co Ltd
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Filing: 1970-06-02
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Granted: 1972-07-25
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Expires: 1990-06-02
Abstract
Abstract At least two timing circuits, one of which is responsive to the light intensity of the object and another of which is set at a fixed delay, are actuated simultaneously to control the opening and closing of a shutter or curtain mechanism in a through-thelens type measuring system. One of the timing circuits is used to open the shutter mechanism and another timing circuit controls the closing of the shutter mechanism. A third timing circuit may be added which has a constant delay equal to that of the another timing circuit and actuates the shutter opening mechanism after an elapsed time interval. The three timing circuits are connected in a series-parallel manner to effect the proper addition and subtraction of their respective time intervals.
Inventors
- 👤 Hiroshi Ueda
- 👤 Kintaro Yata
- 👤 Motonobu Matsuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:33
CPC Classifications
G; G03; G03B; G03B19/00; G03B19/02; G03B19/12; G03B7/00; G03B7/08; G03B7/081; G03B7/083
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
210 words
A shutter control mechanism for a photographic camera including an exposure control circuit having a photoelectric element for receiving light from an object to be photographed through an objective lens of the camera, comprising; a shutter opening member; a first member for restraining the opening member in a cocked position thereof; a first electromagnetic means for releasing said opening member and actuating shutter opening operation; a shutter closing member; a second member for restraining said closing member in a cocked position thereof; a second electromagnetic means for releasing the closing member and actuating shutter closing operation; a first timing circuit having a delay period determined by the light incident on the photoelectric element and electrically connected to said first electromagnetic means for actuating The latter after the lapse of said delay period; a second timing circuit having a constant delay period and connected electrically to said second electromagnetic means for actuating the latter after the lapse of the constant delay period; a manually operated switch means for actuating said timing circuits simultaneously; and an electric power source to which said two timing circuits are connected in parallel with each other through said switch means, said constant delay period is set longer than said delay period of the first timing circuit.
Claim 2
Dependent Claim
210 words
A shutter control mechanism for a photographic camera including an exposure control circuit having a photoelectric element for receiving light from an object to be photographed through an objective lens of the camera, comprising; a shutter opening member; a first member for restraining the opening member in a cocked position thereof; a first electromagnetic means for releasing said opening member and actuating shutter opening operation; a shutter closing member; a second member for restraining said closing member in a cocked position thereof; a second electromagnetic means for releasing the closing member and actuating shutter closing operation; a first timing circuit having a delay period determined by the light incident on the photoelectric element and electrically connected to said first electromagnetic means for actuating The latter after the lapse of said delay period; a second timing circuit having a constant delay period and connected electrically to said second electromagnetic means for actuating the latter after the lapse of the constant delay period; a manually operated switch means for actuating said timing circuits simultaneously; and an electric power source to which said two timing circuits are connected in parallel with each other through said switch means, said constant delay period is set longer than said delay period of the first timing circuit.
Claim 3
Dependent Claim
77 words
A shutter control mechanism as in claim 1, wherein said first timing circuit includes an inductance and a photoconductive element connected in series with each other, and a first switching circuit connected between said photoconductive element and said inductance and said first electromagnetic means; the second timing circuit including a fixed resistance and a condenser connected in series with each other, and a second switching circuit connected between said condenser and resistance and said second electromagnetic means.
Claim 4
Dependent Claim
131 words
A shutter control mechanism as in claim 1 further comprising: a delay circuit having a fixed resistance and a condenser connected in series with each other; a first switching circuit having an input terminal connected between said fixed resistance and said condenser, and an output terminal connected to said second electromagnetic means; a voltage divider having an ohmic resistance and a photoconductive element connected in series with each other; a differential amplifier circuit having two input terminals, one of which is connected between said ohmic resistance and said photoconductive element, the other input terminal is connected between said condenser and said fixed resistance, and an output terminal; and a second switching circuit having an input terminal connected to said output terminal, and an output terminal connected to said first electromagnetic means.
Claim 5
Dependent Claim
111 words
A shutter mechanism as in claim 1, wherein: said shutter opening member is a front shutter curtain; said shutter closing member is a rear shutter curtain; said second member includes a first armature attracted by said second electromagnetic means; a reflector movable between a rest position and an operating position; and a third member for restraining said reflector in said rest position and including a second armature attracted by said first electromagnetic means for releasing the restraint of said reflector, said first member is mounted in the camera so that the restraint of the first member is released in response to the movement of said reflector to the operating position thereof.
Claim 6
Dependent Claim
214 words
A shutter mechanism as in claim 1, comprising; a blade means as the lens shutter; an operating ring movable between a first position for opening said blade means and a second position for closing said blade means; said first member restrains said operating ring in said first position and including a first armature fixed thereon to be attracted by said first electromagnetic means; a reflector movable between a rest position and an operating position and biased in said operating position; said second member restrains said reflector in said rest position, the restraint of the second restraining member is released in response to the movement of said operating ring from said first position to said second position; a first driving member for driving said operating ring to said first position; a third member for restraining said first driving member in a cocked position, which restraint is released in response to the movement of said reflector to said operating position; a second driving member for driving said operating ring to said second position; and a fourth member for restraining said second driving member in a charged position and including a second armature fixed thereon to be attracted by said second electromagnetic means for releasing the restrainT of said fourth member and actuating said second driving member.
Claim 7
Dependent Claim
101 words
A shutter mechanism as in claim 1 further comprising; a third timing circuit having a constant delay period equal to that of said second timing circuit and connected to said first electromagnetic means for actuating said first electromagnetic means after the lapse of said constant delay period, said constant delay period is set longer than said delay period of said first timing circuit; said manually operated switch means initiates operation of said first and said third timing circuits simultaneously; and said first and third timing circuits are connected in parallel with each other through said switch means to said power source.
Claim 8
Dependent Claim
196 words
A shutter mechanism as in claim 6, wherein said first timing circuit includes a photoconductive element and a condenser connected in series with each other; said second timing circuit includes a first silicon control rectifier and a delay circuit having an ohmic resistance and a condenser, a second silicon control rectifier in parallel with said delay circuit and said second electromagnet coil is connected to said first silicon control rectifier and the gate of said second silicon control rectifier is connected between said ohmic resistance and said condenser in said RC delay circuit, the gate of said first silicon control rectifier is connected between said photoconductive element and said condenser in said first timing circuit for actuating said second electromagnetic means; and said third timing circuit includes a delay circuit having an ohmic resistance and a condenser, and having a delay period equal to that of said delay circuit in said second timing circuit, and a third silicon control rectifier, and said first electromagnetic coil is connected in series with said delay circuit, the gate of said third silicon control rectifier is connected between said ohmic resistance and said condenser for actuating said first electromagnetic means.
Claim 9
Dependent Claim
101 words
A shutter mechanism as in claim 4 further comprising; a third timing circuit having a constant delay period equal to that of said second timing circuit and connected to said first electromagnetic means for actuating said first electromagnetic means after the lapse of said constant delay period, said constant delay period is set longer than said delay period of said first timing circuit; said manually operated switch means initiates operation of said first and said third timing circuits simultaneously; and said first and third timing circuits are connected in parallel with each other through said switch means to said power source.
Claim 10
Dependent Claim
101 words
A shutter mechanism as in claim 5, further comprising; a third timing circuit having a constant delay period equal to that of said second timing circuit and connected to said first electromagnetic means for actuating said first electromagnetic means after the lapse of said constant delay period, said constant delay period is set longer than said delay period of said first timing circuit; said manually operated switch means initiates operation of said first and said third timing circuits simultaneously; and said first and third timing circuits are connected in parallel with each other through said switch means to said power source.
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) | 1975-07-25 | 1976-01-24 | 1976-07-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-25 | 1980-01-24 | 1980-07-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-25 | 1984-01-24 | 1984-07-25 | $7700.00 | Window Closed / Lapsed |