Patent US2673489A successfully refreshed from Google Patents.
US2673489A
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Incandescent light source and condensing system for optical projectors
Assignee: American Optical Corp
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Filing: 1950-09-21
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Granted: 1954-03-30
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Expires: 1970-09-21
Abstract
No abstract record available.
Inventors
- 👤 David I Critoph
- 👤 Albin A Gradisar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:25
CPC Classifications
G; G03; G03B; G03B21/00; G03B21/14; G03B21/20; G03B21/208
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1313857A
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US1213975A
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US1213974A
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US1239371A
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US1709017A
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US1991861A
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US1962356A
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US2485377A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-03-29 | 1957-09-28 | 1958-03-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-03-29 | 1961-09-28 | 1962-03-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-03-29 | 1965-09-28 | 1966-03-30 | $7700.00 | Window Closed / Lapsed |