US2528681A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical indicator
Assignee: —
•
Filing: —
•
Granted: 1950-11-07
•
Expires: 1967-11-07
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 01:59
CPC Classifications
G; G02; G02B; G02B30/00; G02B30/20; G02B30/22; G02B30/25; H; H04; H04N; H04N13/00; H04N13/30; H04N13/332; H04N13/337
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US778891A
Cited
US934916A
Cited
US1503766A
Cited
US1599718A
Cited
US1665426A
Cited
US2307981A
Cited
US2357542A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-11-06 | 1954-05-08 | 1954-11-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-11-06 | 1958-05-08 | 1958-11-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-11-06 | 1962-05-08 | 1962-11-07 | $7700.00 | Window Closed / Lapsed |