Patent US4486690A successfully refreshed from Google Patents.
US4486690A
Expired / Lapsed
US
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Test flash device for flash discharger
Assignee: Fuji Koeki Corp
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Filing: 1984-02-14
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Granted: 1984-12-04
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Expires: 2004-02-14
Abstract
Abstract A test flash device in a photographic flash discharger which includes a photometric circuit including an integrator and exposed to light emitted from a flash discharger tube and reflected by an object to be photographed. A light emission stopping circuit is provided to stop light emission in response to a signal from the photometric circuit. A display circuit is provided to present a change in display when light emission stops. A test flash circuit is provided which regulates the time of light emission during test flashing to a predetermined short time.
Inventors
- 👤 Yoshiyuki Takematsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 10:13
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/30; H05B41/32; H05B41/325; G; G03; G03B; G03B15/00; G03B15/02; G03B15/03; G03B15/05; G03B2215/00; G03B2215/05
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
169 words
A test flash device in a flash discharger including a flash discharge tube comprising a photometric circuit exposed to light emitted from the flash discharge tube and reflected by an object to be photographed, a light emission stopping circuit adapted to stop said light emission of said flash discharge tube in response to a photometric signal from said photometric circuit, a display circuit adapted to present a change in display when light emission stopping occurs, a test flash circuit adapted to provide test flashing prior to flash photographing, a circuit to regulate the light emission quantity of the flash discharge tube for test flashing to a quantity smaller than that for an actual flash photographing and a circuit to regulate a time integrated by an integrator included in said photometric circuit depending on said light emission quantity for test flashing so that generation of a signal representing a predetermined level of the integration value in said integrator occurs at an earlier point with respect to said actual flash photographing.
Claim 2
Dependent Claim
169 words
A test flash device in a flash discharger including a flash discharge tube comprising a photometric circuit exposed to light emitted from the flash discharge tube and reflected by an object to be photographed, a light emission stopping circuit adapted to stop said light emission of said flash discharge tube in response to a photometric signal from said photometric circuit, a display circuit adapted to present a change in display when light emission stopping occurs, a test flash circuit adapted to provide test flashing prior to flash photographing, a circuit to regulate the light emission quantity of the flash discharge tube for test flashing to a quantity smaller than that for an actual flash photographing and a circuit to regulate a time integrated by an integrator included in said photometric circuit depending on said light emission quantity for test flashing so that generation of a signal representing a predetermined level of the integration value in said integrator occurs at an earlier point with respect to said actual flash photographing.
Claim 3
Dependent Claim
65 words
A test flash device according to claim 1, wherein said test flash circuit includes a timing circuit adapted to be energization-controlled in association with the test flashing and to activate said light emission stopping circuit with a voltage signal of a predetermined value, and said photometric circuit includes two capacitors of different capacities, one of which is selected to operate in association with test flashing.
Claim 4
Dependent Claim
48 words
A test flash device according to claim 1, wherein said photometric circuit includes two capacitors connected in series so that one of these capacitors is short-circuited upon closure of a trigger switch for flash photographing and both of the capacitors take part in light measuring during test flashing.
Claim 5
Dependent Claim
138 words
A test flash device in a flash discharger including a flash discharge tube comprising a photometric circuit exposed to light emitted from the flash discharge tube and reflected by an object to be photographed, a comparator circuit adapted to generate a signal for activating a light emission stopping circuit when a photometric signal from said photometric circuit exceeds a predetermined value, a display circuit adapted to present a change in display when light emission stopping occurs, a test flash circuit adapted to provide test flashing prior to a flash photographing, a circuit to regulate the light emission quantity of the flash discharge tube for test flashing to a quantity smaller than that for an actual flash photographing and a circuit to regulate a reference signal applied to said comparator depending on said light emission quantity for test flashing.
Claim 6
Dependent Claim
138 words
A test flash device in a flash discharger including a flash discharge tube comprising a photometric circuit exposed to light emitted from the flash discharge tube and reflected by an object to be photographed, a comparator circuit adapted to generate a signal for activating a light emission stopping circuit when a photometric signal from said photometric circuit exceeds a predetermined value, a display circuit adapted to present a change in display when light emission stopping occurs, a test flash circuit adapted to provide test flashing prior to a flash photographing, a circuit to regulate the light emission quantity of the flash discharge tube for test flashing to a quantity smaller than that for an actual flash photographing and a circuit to regulate a reference signal applied to said comparator depending on said light emission quantity for test flashing.
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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) | 1987-12-04 | 1988-06-04 | 1988-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-12-04 | 1992-06-04 | 1992-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-12-04 | 1996-06-04 | 1996-12-04 | $7700.00 | Window Closed / Lapsed |