US2453218A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Image forming optical lens system athermalized for focal point
Assignee: Polaroid Corp
•
Filing: 1946-03-05
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Granted: 1948-11-09
•
Expires: 1966-03-05
Abstract
No abstract record available.
Inventors
- 👤 David S Grey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:43
CPC Classifications
G; G02; G02B; G02B13/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1325936A
Cited
US2193742A
Cited
US2314838A
Cited
GB490381A
Cited
US2330663A
Cited
US2405301A
Cited
US2406762A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-11-09 | 1952-05-10 | 1952-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-11-09 | 1956-05-10 | 1956-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-11-09 | 1960-05-10 | 1960-11-09 | $7700.00 | Window Closed / Lapsed |