Patent US4256995A successfully refreshed from Google Patents.
US4256995A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electronic pre-emission flash device
Assignee: Minolta Co Ltd
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Filing: 1979-03-19
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Granted: 1981-03-17
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Expires: 1999-03-19
Abstract
Abstract An electronic flash device capable of emitting a flash light of a regulated level over a considerable duration of time, prior to flash firing for emitting a torrent of flash light for flash photography. The device is provided with two capacitors, one of which is discharged through the flash tube and a current regulation circuit upon actuation of a first trigger switch, and the other of which, for example in relation to shutter release operation, is discharged through the flash tube without regulation of the discharge current upon subsequent actuation of a second trigger switch in relation to shutter opening. The pre-emission of flash light may be used for automatic focusing, automatic diaphragm determination and automatic flash control.
Inventors
- 👤 Tokuji Ishida
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 07:34
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/30; H05B41/32
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
99 words
An electronic flash device comprising: an electronic flash tube; a first energizing means for energizing said flash tube with a regulated current; a second energizing means for energizing said flash tube with non-regulated electric current, a switch means for actuating said second energizing means, a first trigger circuit for triggering said flash tube with said switch means deactuated so that said flash tube may be energized by said first energizing means, and a second trigger circuit for triggering said flash tube and actuating said switch means subsequent to the triggering of said flash tube by said first trigger circuit.
Claim 2
Dependent Claim
99 words
An electronic flash device comprising: an electronic flash tube; a first energizing means for energizing said flash tube with a regulated current; a second energizing means for energizing said flash tube with non-regulated electric current, a switch means for actuating said second energizing means, a first trigger circuit for triggering said flash tube with said switch means deactuated so that said flash tube may be energized by said first energizing means, and a second trigger circuit for triggering said flash tube and actuating said switch means subsequent to the triggering of said flash tube by said first trigger circuit.
Claim 3
Dependent Claim
42 words
An electronic flash device as in claim 1 wherein said first energizing means includes a first capacitor for storing electric energy to be supplied to said flash tube, and means for regulating the current through said flash tube independently of exposure conditions.
Claim 4
Dependent Claim
47 words
An electronic flash tube as in claim 2 wherein said second energizing means includes a second capacitor for storing electric energy to be supplied to said flash tube, and said first and second energizing means are connected substantially in parallel with one another to said flash tube.
Claim 5
Dependent Claim
33 words
An electronic flash tube as in claim 2 wherein said means for regulating includes current regulation means and means for feeding back information of the electric current flowing through said current regulation means.
Claim 6
Dependent Claim
42 words
An electronic flash device as in claim 3 wherein said switch means includes a semiconductor switching element serially connected between said flash tube and said second capacitor, and said first and second energizing means are arranged substantially in parallel with each other.
Claim 7
Dependent Claim
70 words
An electronic flash device comprising: an electronic flash tube; a first circuit loop including said flash tube, a first capacitor and means for regulating the current flowing through said first circuit loop; a second circuit loop including said flash tube, a second capacitor and an electronic switch element; and trigger means for firing said flash tube at first through said first circuit loop and subsequently through said second circuit loop.
Claim 8
Dependent Claim
70 words
An electronic flash device comprising: an electronic flash tube; a first circuit loop including said flash tube, a first capacitor and means for regulating the current flowing through said first circuit loop; a second circuit loop including said flash tube, a second capacitor and an electronic switch element; and trigger means for firing said flash tube at first through said first circuit loop and subsequently through said second circuit loop.
Claim 9
Dependent Claim
62 words
An electronic flash device as in claim 6 wherein said trigger means includes a trigger circuit for applying a trigger signal to said flash tube, first actuation means for actuating said trigger circuit and said means for regulating, second actuation means for actuating said trigger circuit and said switch element, and means for preventing interference between said first and second actuation means.
Claim 10
Dependent Claim
48 words
An electronic flash device as in claim 7 wherein said trigger circuit includes a trigger capacitor and means for charging said trigger capacitor right after the flash tube triggering through said first circuit loop for the preparation for the next flash tube triggering through said second circuit loop.
References Cited (Backward Citations)
US3681649A
Cited
US3846811A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-16 | 1984-09-15 | 1985-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-16 | 1988-09-15 | 1989-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-16 | 1992-09-15 | 1993-03-17 | $7700.00 | Window Closed / Lapsed |