Patent US3589805A successfully refreshed from Google Patents.
US3589805A
Expired / Lapsed
US
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Ac exposure control device for a camera
Assignee: Eastman Kodak Co
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Filing: 1969-05-29
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Granted: 1971-06-29
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Expires: 1989-05-29
Abstract
Abstract An exposure control apparatus is disclosed which includes a source of DC potential; means coupled to the DC source for producing an alternating voltage; a first signal lamp coupled to the alternating voltage producing means and adapted to indicate whether or not the DC potential is above a selected level; photosensitive means having an electrical parameter that varies inversely with the intensity of viewed scene light; and a second signal lamp operatively coupled to the alternating voltage producing means and the photosensitive means and adapted to indicate if scene illumination is sufficient to expose film.
Inventors
- 👤 Allen G Stimson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:00
CPC Classifications
G; G03; G03B; G03B17/00; G03B17/18; G03B17/20
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
147 words
In a motion picture camera having means for receiving a film, means for receiving a DC power source, and a DC motor operatively connectable to the received DC power source for advancing a received film, an exposure control device comprising: a transformer having a primary winding electrically connected in series relationship to the DC power source and the DC motor and a secondary winding for providing a source of alternating voltage; photoelectric means operatively connected to said source of alternating voltage for receiving radiation from a scene, said photoelectric means having an electrical parameter that is variable in relation to the intensity of the radiation received from the scene; and means operatively connected to, and responsive to variations in the electrical parameter of, said photoelectric means for indicating whether the intensity of radiation from the scene is suitable to effect a satisfactory exposure of the received film.
Claim 2
Dependent Claim
147 words
In a motion picture camera having means for receiving a film, means for receiving a DC power source, and a DC motor operatively connectable to the received DC power source for advancing a received film, an exposure control device comprising: a transformer having a primary winding electrically connected in series relationship to the DC power source and the DC motor and a secondary winding for providing a source of alternating voltage; photoelectric means operatively connected to said source of alternating voltage for receiving radiation from a scene, said photoelectric means having an electrical parameter that is variable in relation to the intensity of the radiation received from the scene; and means operatively connected to, and responsive to variations in the electrical parameter of, said photoelectric means for indicating whether the intensity of radiation from the scene is suitable to effect a satisfactory exposure of the received film.
Claim 3
Dependent Claim
26 words
The device claimed in claim 1 wherein said secondary winding has more turns than does said primary winding to provide a source of amplified alternating voltage.
Claim 4
Dependent Claim
26 words
The device claimed in claim 1 further comprising means operatively connected to said source of alternating voltage for indicating whether the DC power source is adequate.
Claim 5
Dependent Claim
25 words
The device claimed in claim 3 wherein each of said radiation intensity indicating means and said DC power source indicating means includes a gas-discharge lamp.
References Cited (Backward Citations)
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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) | 1974-06-28 | 1974-12-28 | 1975-06-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-28 | 1978-12-28 | 1979-06-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-28 | 1982-12-28 | 1983-06-29 | $7700.00 | Window Closed / Lapsed |