US3547520A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stereoscope
Assignee: Northrop Grumman Guidance and Electronics Co Inc
•
Filing: 1967-12-13
•
Granted: 1970-12-15
•
Expires: 1987-12-13
Abstract
No abstract record available.
Inventors
- 👤 Roger K Lee
- 👤 Richard W Dyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 10:09
CPC Classifications
G; G02; G02B; G02B30/00; G02B30/20; G02B30/34; G02B30/35
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
FR505180A
Cited
US2036554A
Cited
US2605352A
Cited
US2361390A
Cited
US2879337A
Cited
FR1160172A
Cited
US3158430A
Cited
US3317206A
Cited
US3337287A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-12-14 | 1974-06-15 | 1974-12-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-12-14 | 1978-06-15 | 1978-12-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-12-14 | 1982-06-15 | 1982-12-15 | $7700.00 | Window Closed / Lapsed |