US2256093A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Material having varying birefringence and method of manufacture
Assignee: POLAROLD Corp
•
Filing: 1938-07-14
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Granted: 1941-09-16
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Expires: 1958-07-14
Abstract
No abstract record available.
Inventors
- 👤 Edwin H Land
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:30
CPC Classifications
B; B44; B44F; B44F1/00; B44F1/08; B44F1/10; G; G02; G02B; G02B5/00; G02B5/30; G02B5/3083; G09; G09F; G09F19/00; G09F19/12; G09F7/00; G09F7/16; G09F7/165
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) | 1944-09-15 | 1945-03-17 | 1945-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1948-09-15 | 1949-03-17 | 1949-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1952-09-15 | 1953-03-17 | 1953-09-16 | $7700.00 | Window Closed / Lapsed |