US3587420A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automatic camera diaphragm system
Assignee: Societe dOptique Precision Electronique et Mecanique SOPELEM SA
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Filing: 1967-09-13
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Granted: 1971-06-28
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Expires: 1987-09-13
Abstract
Abstract AN AUTOMATIC CAMERA DIAPHRAGM CONTROL USES A PHOTO RESISTANT CELL WHICH RECEIVES LIGHT THROUGH THE DIAPHRAGM. THE CELL IS SUPPLIED WITH AN ADJUSTABLE CONSTANT CURRENT. AN OVERALL SENSITIVITY RESULTS WHICH IS INDEPENDENT OF NOMINAL ILLUMINATION AND WHICH DEPENDS SOLELY ON THE RELATIVE VARIATIONS OF ILLUMINATION.
Inventors
- 👤 Helenio Llop
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:54
CPC Classifications
G; G03; G03B; G03B7/00; G03B7/08; G03B7/081; G03B7/085
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-06-27 | 1974-12-27 | 1975-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-27 | 1978-12-27 | 1979-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-27 | 1982-12-27 | 1983-06-28 | $7700.00 | Window Closed / Lapsed |