Patent US3690237A successfully refreshed from Google Patents.
US3690237A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic flashlight device for flashlight photography
Assignee: Naka Magome KK
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Filing: 1970-09-22
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Granted: 1972-09-12
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Expires: 1990-09-22
Abstract
Abstract A device particularly for use with a camera having an electronic flash and a shutter but no diaphragm control so that the flash will be produced at some time before the shutter has completely opened. In order to regulate the light passing through the shutter, in one embodiment a switch is closed when the shutter begins to open to permit a capacitor to discharge through a variable resistor until its voltage reaches a point where two transistors are switched to produce a signal which enables the capacitor to discharge through a discharge tube which then produces an electronic flash. In a second embodiment, when the switch is open, a capacitor begins to charge through a variable resistor and when the capacitor has charged to a given level, a transistor switching circuit is triggered to apply a trigger signal to the flash tube.
Inventors
- 👤 Zydichi Fuwa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 18:37
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/30; H05B41/32; G; G03; G03B; G03B15/00; G03B15/02; G03B15/03; G03B15/05; G03B2215/00; G03B2215/05
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
300 words
Apparatus for use with a camera of the type operating with a shutter only comprising: a discharge tube for producing a light flash for photography, means for causing said tube to produce said light flash including a capacitor, means to charge said capacitor and means for discharging said capacitor through said discharge tube when an electrical signal is applied to said discharging means, switch means for shifting from an open to a closed electrical condition when said shutter is opened, and variable delay means electrically connected to said causing means and to said switch means for producing said electrical signal a variable time after said switch means shifts from said open to said closed condition, said variable time being selected to operate when said shutter reaches a preset opening, said signal being applied to said causing means so that said tube thereafter produces said flash, wherein said delay means includes a second capacitor, means for charging said second capacitor, a variable resistor connected across said second capacitor via said switch means so that said capacitor discharges through said variable resistor, at a rate determined by the resistance of said variable resistor, when said switch means is closed, wherein said discharging means includes a first transistor electrically connected to said second capacitor, a second transistor connected to said first transistor so that said second transistor shifts from a first to a second electrical condition when said second capacitor discharges to a given level and electrical trigger means connected to said second transistor for applying a trigger signal to said flash tube when said second transistor shifts to said second condition so that the first capacitor discharges through said tube to produce said light flash at a time after said switch means was closed determined by the resistance of said variable resistance.
Claim 2
Dependent Claim
300 words
Apparatus for use with a camera of the type operating with a shutter only comprising: a discharge tube for producing a light flash for photography, means for causing said tube to produce said light flash including a capacitor, means to charge said capacitor and means for discharging said capacitor through said discharge tube when an electrical signal is applied to said discharging means, switch means for shifting from an open to a closed electrical condition when said shutter is opened, and variable delay means electrically connected to said causing means and to said switch means for producing said electrical signal a variable time after said switch means shifts from said open to said closed condition, said variable time being selected to operate when said shutter reaches a preset opening, said signal being applied to said causing means so that said tube thereafter produces said flash, wherein said delay means includes a second capacitor, means for charging said second capacitor, a variable resistor connected across said second capacitor via said switch means so that said capacitor discharges through said variable resistor, at a rate determined by the resistance of said variable resistor, when said switch means is closed, wherein said discharging means includes a first transistor electrically connected to said second capacitor, a second transistor connected to said first transistor so that said second transistor shifts from a first to a second electrical condition when said second capacitor discharges to a given level and electrical trigger means connected to said second transistor for applying a trigger signal to said flash tube when said second transistor shifts to said second condition so that the first capacitor discharges through said tube to produce said light flash at a time after said switch means was closed determined by the resistance of said variable resistance.
Claim 3
Dependent Claim
33 words
Apparatus as in claim 1 including a neon light connected to said first capacitor for indicating when said capacitor is charged to a level sufficient to cause said tube to produce said flash.
Claim 4
Dependent Claim
311 words
Apparatus for use with a camera of the type operating with only a shutter comprising: a discharge tube for producing a light flash for photography, means for causing said flash means to produce said light flash, including a capacitor, means to charge said capacitor and means for discharging said capacitor through said discharge tube when an electrical signal is applied to said discharging means, switch means for shifting from a closed to an open electrical condition when said shutter is opened, and variable delay means electrically connected to said causing means and to said switch means for producing said electrical signal a variable time after said switch means shifts from said closed to said open condition, said variable time being selected to operate when said shutter reaches a preset opening, said signal being applied to said causing means so that said flash means thereafter produceS said flash, wherein said delay means includes a second capacitor, means for charging said second capacitor, a variable resistor connected in series with said second capacitor with said switch means connected in parallel with said second capacitor so that said capacitor charges through said variable resistor, at a rate determined by the resistance of said variable resistor, when said switch means is open, wherein said discharging means includes a first transistor electrically connected to said second capacitor, a second transistor connected to said first transistor so that said second transistor shifts from a first to a second electrical condition when said second capacitor charges to a given level and electrical trigger means connected to said second transistor for applying a trigger signal to said flash tube when said second transistor shifts to said second condition so that the first capacitor discharges through said tube to produce said light flash at a time after said switch means was opened determined by the resistance of said variable resistance.
Claim 5
Dependent Claim
311 words
Apparatus for use with a camera of the type operating with only a shutter comprising: a discharge tube for producing a light flash for photography, means for causing said flash means to produce said light flash, including a capacitor, means to charge said capacitor and means for discharging said capacitor through said discharge tube when an electrical signal is applied to said discharging means, switch means for shifting from a closed to an open electrical condition when said shutter is opened, and variable delay means electrically connected to said causing means and to said switch means for producing said electrical signal a variable time after said switch means shifts from said closed to said open condition, said variable time being selected to operate when said shutter reaches a preset opening, said signal being applied to said causing means so that said flash means thereafter produceS said flash, wherein said delay means includes a second capacitor, means for charging said second capacitor, a variable resistor connected in series with said second capacitor with said switch means connected in parallel with said second capacitor so that said capacitor charges through said variable resistor, at a rate determined by the resistance of said variable resistor, when said switch means is open, wherein said discharging means includes a first transistor electrically connected to said second capacitor, a second transistor connected to said first transistor so that said second transistor shifts from a first to a second electrical condition when said second capacitor charges to a given level and electrical trigger means connected to said second transistor for applying a trigger signal to said flash tube when said second transistor shifts to said second condition so that the first capacitor discharges through said tube to produce said light flash at a time after said switch means was opened determined by the resistance of said variable resistance.
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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) | 1975-09-12 | 1976-03-13 | 1976-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-09-12 | 1980-03-13 | 1980-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-09-12 | 1984-03-13 | 1984-09-12 | $7700.00 | Window Closed / Lapsed |