US2819404A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Optical image-forming mirror systems having aspherical reflecting surfaces
Assignee: Individual
•
Filing: 1952-05-20
•
Granted: 1958-01-07
•
Expires: 1972-05-20
Abstract
No abstract record available.
Inventors
- 👤 Herrnring Gunther
- 👤 Weidner Walter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:49
CPC Classifications
G; G02; G02B; G02B17/00; G02B17/02; G02B17/06; G21; G21K; G21K7/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1016369A
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US1865441A
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US1943510A
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US2077740A
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US2534543A
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US2653249A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-01-06 | 1961-07-08 | 1962-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-01-06 | 1965-07-08 | 1966-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-01-06 | 1969-07-08 | 1970-01-07 | $7700.00 | Window Closed / Lapsed |