Patent US2663222A successfully refreshed from Google Patents.
US2663222A
Expired / Lapsed
US
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Three-element objective lens with reduced spherical aberration and chromatic difference of spherical aberration
Assignee: Farrand Optical Co Inc
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Filing: 1951-02-23
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Granted: 1953-12-22
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Expires: 1971-02-23
Abstract
No abstract record available.
Inventors
- 👤 Rosin Seymour
- 👤 Angela M Bottalico
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:13
CPC Classifications
G; G02; G02B; G02B9/00; G02B9/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
DE189255C
Cited
US554737A
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US682017A
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GB190607661A
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US1035408A
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US1159233A
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US1514356A
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GB309085A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-12-21 | 1957-06-22 | 1957-12-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-12-21 | 1961-06-22 | 1961-12-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-12-21 | 1965-06-22 | 1965-12-22 | $7700.00 | Window Closed / Lapsed |