US3806789A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit arrangement for diaphragm control
Assignee: Canon Inc
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Filing: 1971-12-09
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Granted: 1974-04-23
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Expires: 1991-12-09
Abstract
Abstract A circuit arrangement, comprising a direct-current source, and means having time constants including an electric motor, having an operative condition and an inoperative condition, the transition from operative to inoperative condition thereof occurring with a predetermined first time constant. A circuit means constituting a closed control loop includes the directcurrent source and the motor to control the same and has feedback means. An amplifier stage within the control circuit is between said direct-current source and the motor, and has a predetermined direct-current gain, and a negative feedback loop on the amplifier stage comprises an integrating means having a predetermined second time constant.
Inventors
- 👤 H Cap
- 👤 H Krammer
- 👤 R Scheiber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:20
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/08; G03B7/081; G03B7/085
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
101 words
A circuit arrangement, comprising a direct-current source, means having time constants including an electric motor having an operative condition and an inoperative condition, the transistion from one condition to the other one occurring with a predetermined first time constant, circuit means constituting a closed control loop including said direct-current source and said motor to control the same and having feedback means, an amplfifier stage within said control circuit between said direct-current source and said motor, said amplifier stage having a predetermined direct-current gain, and a negative feedback loop on said amplifier stage comprising integrating means having a predetermined second time constant.
Claim 2
Dependent Claim
101 words
A circuit arrangement, comprising a direct-current source, means having time constants including an electric motor having an operative condition and an inoperative condition, the transistion from one condition to the other one occurring with a predetermined first time constant, circuit means constituting a closed control loop including said direct-current source and said motor to control the same and having feedback means, an amplfifier stage within said control circuit between said direct-current source and said motor, said amplifier stage having a predetermined direct-current gain, and a negative feedback loop on said amplifier stage comprising integrating means having a predetermined second time constant.
Claim 3
Dependent Claim
51 words
A circuit arrangement as set forth in claim 1, which further comprises, a differentiating stage having a predetermined direct-current voltage gain and connected between said direct-current source and said motor and adapted to feed said motor from said direct-current source, a comparator circuit connected between said direct-current source and said motor.
Claim 4
Dependent Claim
23 words
A circuit arrangement as set forth in claim 1, in which said comparator circuit is connected between said amplifier stage and said motor.
Claim 5
Dependent Claim
23 words
A circuit arrangement as set forth in claim 1, in which said integrating means comprises a feedback loop comprising an integrating resistance-capacitance circuit.
Claim 6
Dependent Claim
20 words
A circuit arrangement as set forth in claim 1, in which said amplifier stage is connected as an astable multivibrator.
Claim 7
Dependent Claim
32 words
A circuit arrangement as set forth in claim 1, in which said amplifier stage comprises an input transistor and a variable voltage divider is connected to the base of said input transistor.
Claim 8
Dependent Claim
20 words
A circuit arrangement as set forth in claim 6, in which said voltage divider includes at least one photoelectric transducer.
Claim 9
Dependent Claim
26 words
A circuit arrangement as set forth in claim 1, wherein said second time constant corresponds to the time constants of said means including said electric motor.
Claim 10
Dependent Claim
22 words
A circuit arrangement as set forth in claim 7, wherein said means having time constants further includes at least one photoelectric transducer.
Claim 11
Dependent Claim
109 words
In a camera a diaphragm to be controlled, a control system for said diaphragm, which comprises a direct-current source, means having time-constants, including an electric motor to move said diaphragm, said motor having an operative and an inoperative condition, the transition between said conditions occurring with a predetermined first time-constant, and photo-electric transducer means arranged to receive light through said diaphragm, said photoelectric transducer means emitting electric signals with a predetermined second time-constant, an amplifier stage connected said direct-current source and said motor, said amplfier stage having a predetermined direct-current source, and a negative feedback loop on said amplifier stage comprising integrating means having a predetermined third time constant.
Claim 12
Dependent Claim
109 words
In a camera a diaphragm to be controlled, a control system for said diaphragm, which comprises a direct-current source, means having time-constants, including an electric motor to move said diaphragm, said motor having an operative and an inoperative condition, the transition between said conditions occurring with a predetermined first time-constant, and photo-electric transducer means arranged to receive light through said diaphragm, said photoelectric transducer means emitting electric signals with a predetermined second time-constant, an amplifier stage connected said direct-current source and said motor, said amplfier stage having a predetermined direct-current source, and a negative feedback loop on said amplifier stage comprising integrating means having a predetermined third time constant.
Claim 13
Dependent Claim
29 words
The camera, as set forth in claim 10, further comprising rotary shutter means having a reflecting surface to reflect light coming through said diaphragm towards saId photoelectric transducer means.
Claim 14
Dependent Claim
132 words
A circuit arrangement, comprising a direct-current source providing positive potential and negative potential, an electric motor having an operative and an inoperative condition, a control network for said motor, said control network comprising means for short-circuiting said motor, the control network including, a bridge circuit having two branches and four diagonal ends, a first pair of transistors of one conductivity type, a second pair of transistors of the other conductivity type, each of said transistors being connected at one of said diagonal ends, mean being operable to render the transistors at opposite ends of a selected diagonal of the bridge circuit conducting, said means for short-circuiting said motor being operable to render those transistors conducting which are included in different branches of the bridge circuit and have the same potential applied thereto.
Claim 15
Dependent Claim
132 words
A circuit arrangement, comprising a direct-current source providing positive potential and negative potential, an electric motor having an operative and an inoperative condition, a control network for said motor, said control network comprising means for short-circuiting said motor, the control network including, a bridge circuit having two branches and four diagonal ends, a first pair of transistors of one conductivity type, a second pair of transistors of the other conductivity type, each of said transistors being connected at one of said diagonal ends, mean being operable to render the transistors at opposite ends of a selected diagonal of the bridge circuit conducting, said means for short-circuiting said motor being operable to render those transistors conducting which are included in different branches of the bridge circuit and have the same potential applied thereto.
Claim 16
Dependent Claim
51 words
A circuit arrangement as set forth in claim 12, in which each of said branches includes a transistor of the first pair and a transistor of the second pair, the transistors of said first pair being connected to one potential, the transistors of said second pair being connected to another potential.
Claim 17
Dependent Claim
120 words
A circuit arrangement as set forth in claim 13, in which, each of said branches includes a transistor of the first pair and a transistor of the second pair, a base voltage divider is associated with each of said transistors, the base voltage dividers associated with the transistors of each branch are interconnected, one of said transistors of each of said branches is arranged to condut when said motor is in said inoperative condition, a control transistor is connected to the junction between the base voltage dividers associated with the transistors of each branch, and the base voltage divider connected to the inoperative condition conducting transistor of each branch comprises an arm connected to said junction and including a diode.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-22 | 1977-10-22 | 1978-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-22 | 1981-10-22 | 1982-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-22 | 1985-10-22 | 1986-04-23 | $7700.00 | Window Closed / Lapsed |