US3683767A
Expired / Lapsed
US
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Electronic shutter system
Assignee: Minolta Co Ltd
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Filing: 1971-06-22
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Granted: 1972-08-15
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Expires: 1991-06-22
Abstract
Abstract An electronic shutter system is comprised of a photoelectric exposure timer and includes an adjustable timer circuit. The exposure timer triggers the adjustable timer which adds an additional amount of exposure time before shutter closure to compensate for delay in shutter opening do to shutter blade overlap.
Inventors
- 👤 Masayoshi Sahara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:42
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/08; G03B7/081; G03B7/083
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
265 words
An electronic shutter system for controlling the opening and closing of a camera shutter comprising: camera shutter control means, connected to said camera shutter, for effecting the opening and closing thereof; a first control circuit, including first means, responsive to the application of input power thereto, for generating a shutter opening signal; a second control circuit, connected to said first control circuit, including second means, responsive to said shutteropening signal, for applying said shutter opening signal to said shutter control means, for effecting the opening of said camera shutter, wherein said first control circuit further includes third means, coupled to said shutter control means and being responsive to the commencement of the opening motion of said camera shutter by said shutter control means, for generating a first timing signal; and wherein said second control circuit further includes fourth means, responsive to the generation of said first timing signal by said third means, for generating a second timing signal and supplying said second timing signal to said shutter control means, whereby said camera shutter will be closed by the application of said second timing signal to said shutter control means, a period of time after the opening thereof. 2. An electronic shutter system according to claim 1, wherein said shutter control means comprises an electromagnetic means connected to said shutter and wherein said third means of said first control circuit includes a photoelectric element and a first capacitor connected in series to form a first timing circuit and being responsive to the brightness of a photographic object for controlling the characteristics of said first timing signal.
Claim 2
Dependent Claim
96 words
An electronic shutter system according to claim 2, wherein said fourth means of said second control circuit comprises a variable resistor and a second capacitor connected together to form a second timing circuit, the charging of said second capacitor being controlled by said first timing signal, anD wherein said second control circuit includes an output transistor switching circuit, the output of which is connected to said electromagnetic means, responsive to the charge accumulation on said second capacitor, for effecting the energization and de-energization of said electromagnetic means, whereby said shutter will be opened and closed thereby.
Claim 3
Dependent Claim
96 words
An electronic shutter system according to claim 2, wherein said fourth means of said second control circuit comprises a variable resistor and a second capacitor connected together to form a second timing signal, the discharging of said second capacitor being controlled by said first timing signal, and wherein said second control circuit includes an output transistor switching circuit, the output of which is connected to said electromagnetic means, responsive to the charge accumulation on said second capacitor, for effecting the energization and de-energization of said electromagnetic means, whereby said shutter will be opened and closed thereby.
Claim 4
Dependent Claim
34 words
An electronic shutter system according to claim 2, wherein said third means of said first control circuit further includes a differential amplifier connected to said photoelectric element and coupled to said second control circuit.
Claim 5
Dependent Claim
33 words
An electronic shutter system according to claim 5, wherein said output transistor switching circuit further includes a compensation transistor circuit connected thereto for effectively compensating said output switching circuit against temperature variations therein.
Claim 6
Dependent Claim
34 words
An electronic switching system according to claim 5, wherein said differential amplifier includes a compensation transistor circuit for protecting said differential amplifier against the dependency thereof on variations in the source voltage applied thereto.
Claim 7
Dependent Claim
41 words
An electronic shutter system according to claim 1, wherein said first means of said first control circuit includes a first transistor switching circuit connected between a source of input power and said second control circuit for delivering said shutter-opening signal thereto.
Claim 8
Dependent Claim
70 words
An electronic shutter system according to claim 8, wherein said third means includes a photoelectric element and a first capacitor switchably connected to said source of input power and to said first transistor switching circuit for controlling the operation thereof in response to the charge accumulation on said first capacitor in accordance with the impedance characteristics of said photoelectric element due to the light impinging thereon from a photographic object.
Claim 9
Dependent Claim
34 words
An electronic shutter system according to claim 9, wherein said first circuit further includes a first switch connected across said first capacitor for short-circuiting said first capacitor during the generation of said shutter-opening signal.
Claim 10
Dependent Claim
35 words
An electronic shutter system according to claim 1, wherein said second means comprises a second transistor switching circuit connected to said first control circuit and said shutter control means for applying said shutter-opening signal thereto.
Claim 11
Dependent Claim
50 words
An electronic shutter system according to claim 11, wherein said fourth means includes a variable resistor and a second capacitor switchably connected to a source of input power and to said second transistor switching circuit for controlling the operation thereof in response to the charge accumulation on said second capacitor.
Claim 12
Dependent Claim
42 words
An electronic shutter system according to claim 12, wherein said second control circuit further includes a second switch connected to said second capacitor, for maintaining said second capacitor in a predetermined state of charge during the generation of said shutter opening signal.
Claim 13
Dependent Claim
47 words
An electronic shutter system according to claim 13, wherein said second switch comprises a transistor switch, the control electrode of which is connected to said first control circuit, so as to charge and discharge said second capacitor in response to the output of said first control circuit.
Claim 14
Dependent Claim
35 words
An electronic shutter system according to claim 8, wherein said second means comprises a second transistor switching circuit connected to said first control circuit and said shutter control means for applying said shutter-opening signal thereto.
Claim 15
Dependent Claim
50 words
An electronic shutter system according to claim 15 wherein said fourth means includes a variable resistor and a second capacitor switchably connected to a source of input power and to said second transistor switching circuit for controlling the operation thereof in response to the charge accumulation on said second capacitor.
Claim 16
Dependent Claim
41 words
An electronic shutter system according to claim 16, wherein said second control circuit further includes a second switch connected to said second capacitor, for maintaining said second capacitor in a predetermined state of charge during the generation of said shutter-opening signal.
Claim 17
Dependent Claim
39 words
An electronic shutter system according to claim 17, wherein said second switch comprises a transistor switch, connected to said first transistor switching circuit, for controlling the charging and discharging of said second capacitor in response to the output thereof.
Claim 18
Dependent Claim
70 words
An electronic shutter system according to claim 18, wherein said third means includes a photoelectric element and a first capacitor switchably connected to said source of input power and to said first transistor switching circuit for controlling the operation thereof in response to the charge accumulation on said first capacitor in accordance with the impedance characteristics of said photoelectric element due to the light impinging thereon from a photographic object.
Claim 19
Dependent Claim
34 words
An electronic shutter system according to claim 19, wherein said first circuit further includes a first switch connected across said first capacitor for short-circuiting said first capacitor during the generation of said shutter-opening signal.
Claim 20
Dependent Claim
55 words
An electronic shutter system according to claim 20, wherein said shutter control means comprises an electromagnetic means and an energizing transistor therefor connected together, said energizing transistor being connected to said second transistor switching circuit, so as to energize and de-energize said electromagnetic means in response to the output of said second transistor switching circuit.
Claim 21
Dependent Claim
32 words
An electronic shutter system according to claim 14, wherein said transistor switch is connected across said second capacitor so as to maintain said capacitor discharged during the generation of said shutter-opening signal.
Claim 22
Dependent Claim
35 words
An electronic shutter system according to claim 14, wherein said transistor switch is connected in series with said second capacitor, so as to maintain said second capacitor charged during the generation of said shutter-opening signal.
Claim 23
Dependent Claim
61 words
An electronic shutter system according to claim 23, wherein said first transistor switching circuit includes a first and a second transistor connected in cascade, the emitter electrode of said first transistor being connected to a voltage divider network, the impedance of which is controllably linked to the diaphragm opening of the lens of said camera and a film sensitivity setting therefor.
Claim 24
Dependent Claim
41 words
An electronic shutter system according to claim 9, wherein said first control circuit further includes a differential amplifier circuit connected between said photoelectric element and said first transistor switching circuit, so as to increase the stability of operation of said circuit.
Claim 25
Dependent Claim
26 words
An electronic shutter system according to claim 25, further including a constant current circuit connected between said source of supply voltage and said differential amplifier circuit.
Claim 26
Dependent Claim
42 words
An electronic shutter system according to claim 26, wherein said constant current circuit comprises a pair of cascaded transistors, a first of which is connected across said source of supply voltage and the second of which is connected to said differential amplifier.
Claim 27
Dependent Claim
53 words
An electronic shutter system according to claim 26, further including a film sensitivity setting circuit comprising first and second transistors, a first of which is connected betweeN said power source and said first capacitor and a second of which is connected between said power source and a first input of said differential amplifier.
Claim 28
Dependent Claim
49 words
An electronic shutter system according to claim 28, further including a variable resistor connected between said second transistor of said film sensitivity setting circuit and said first input of said differential amplifier, whereby the first input applied to said differential amplifier is adjusted in dependence of said film sensitivity.
Claim 29
Dependent Claim
26 words
An electronic shutter system according to claim 29, wherein the second input of said differential amplifier is connected to said first capacitor and said photoelectric element.
Claim 30
Dependent Claim
31 words
An electronic shutter system according to claim 30, further including a first thermal compensation transistor circuit connected to the input of said first transistor switching circuit for providing thermal compensation therefor.
Claim 31
Dependent Claim
57 words
An electronic shutter system according to claim 31, wherein said second means comprises a second transistor switching circuit connected to said first control circuit and said shutter control means for applying said shutter opening signal thereto, and further includes a second thermal compensation transistor circuit connected to said second transistor switching circuit for providing thermal compensation therefor.
References Cited (Backward Citations)
US3500729A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-15 | 1976-02-14 | 1976-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-15 | 1980-02-14 | 1980-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-15 | 1984-02-14 | 1984-08-15 | $7700.00 | Window Closed / Lapsed |