US2785601A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical device for the observation of transparent objects
Assignee: Centre National de la Recherche Scientifique
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Filing: 1952-11-10
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Granted: 1957-03-19
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Expires: 1972-11-10
Abstract
No abstract record available.
Inventors
- 👤 Francon Maurice Michel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:21
CPC Classifications
G; G02; G02B; G02B21/00; G02B21/06; G02B21/08; G02B21/14
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-03-18 | 1960-09-17 | 1961-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-03-18 | 1964-09-17 | 1965-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-03-18 | 1968-09-17 | 1969-03-19 | $7700.00 | Window Closed / Lapsed |