US2409853A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical instrument for examining polarized light
Assignee: American Optical Corp
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Filing: 1943-01-21
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Granted: 1946-10-22
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Expires: 1963-01-21
Abstract
No abstract record available.
Inventors
- 👤 Paul C Heijn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 18:16
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/28
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) | 1949-10-21 | 1950-04-22 | 1950-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1953-10-21 | 1954-04-22 | 1954-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1957-10-21 | 1958-04-22 | 1958-10-22 | $7700.00 | Window Closed / Lapsed |