US2656761A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Large-aperature optical system comprising two reflecting and refracting spherical suraces in axial alignment
Assignee: Optische Industrie de Oude Delft NV
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Filing: 1950-10-09
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Granted: 1953-10-27
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Expires: 1970-10-09
Abstract
No abstract record available.
Inventors
- 👤 Blaisse Berndt Stephan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:31
CPC Classifications
G; G02; G02B; G02B17/00; G02B17/08; G02B17/0856; G02B17/086; G02B17/0804; G02B17/0808; G02B17/0836; G02B17/084; G02B21/00; G02B21/02; G02B21/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2378301A
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US2448699A
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US2520636A
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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) | 1956-10-26 | 1957-04-27 | 1957-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-10-26 | 1961-04-27 | 1961-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-10-26 | 1965-04-27 | 1965-10-27 | $7700.00 | Window Closed / Lapsed |