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US2590906A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reflection interference filter
Assignee: Farrand Optical Co Inc
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Filing: 1946-11-22
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Granted: 1952-04-01
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Expires: 1966-11-22
Abstract
No abstract record available.
Inventors
- 👤 Kenneth F Tripp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:42
CPC Classifications
G; G02; G02B; G02B5/00; G02B5/20; G02B5/28; G02B5/284
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
131 words
AN OPTICAL REFLECTION FILTER OPERATING BY LIGHT RAY INTERFERENCE AND ABSORPTION COMPRISING A SUBSTANTIALLY OPAQUE LAYER OF A METAL SELECTED FROM THE GROUP CONSISTING OF SILVER AND ALUMINUM, SAID OPAQUE LAYER BEING DEPOSITED ON A GLASS SUPPORT, A SUBSTANTIALLY TRANSPARENT LAYER OF A DIELECTRIC SELECTED FROM THE GROUP CONSISTING OF MAGNESIUM FLUORIDE AND CALCIUM FLUORIDE, SAID TRANSPARENT LAYER BEING DEPOSITED ON SAID OPAQUE LAYER AND HAVING A THICKNESS NOT EXCEEDING 10</N IN WHICH< REPRESENTS A WAVE LENGTH AT WHICH THE FILTER REFLECTS A MAXIMUM OF LIGHT AND N REPRESENTS THE INDEX OF REFRACTION OF SAID TRANSPARENT LAYER, AND A SEMITRANSPARENT LAYER OF A METAL SELECTED FROM THE GROUP CONSISTING OF SILVER AND ALUMINUM, SAID SEMITRANSPARENT LAYER BEING DEPOSITED ON SAID TRANSPARENT LAYER AND HAVING A TRANSMISSION BETWEEN SUBSTANTIALLY 25% AND 65%.
Claim 2
Dependent Claim
131 words
AN OPTICAL REFLECTION FILTER OPERATING BY LIGHT RAY INTERFERENCE AND ABSORPTION COMPRISING A SUBSTANTIALLY OPAQUE LAYER OF A METAL SELECTED FROM THE GROUP CONSISTING OF SILVER AND ALUMINUM, SAID OPAQUE LAYER BEING DEPOSITED ON A GLASS SUPPORT, A SUBSTANTIALLY TRANSPARENT LAYER OF A DIELECTRIC SELECTED FROM THE GROUP CONSISTING OF MAGNESIUM FLUORIDE AND CALCIUM FLUORIDE, SAID TRANSPARENT LAYER BEING DEPOSITED ON SAID OPAQUE LAYER AND HAVING A THICKNESS NOT EXCEEDING 10</N IN WHICH< REPRESENTS A WAVE LENGTH AT WHICH THE FILTER REFLECTS A MAXIMUM OF LIGHT AND N REPRESENTS THE INDEX OF REFRACTION OF SAID TRANSPARENT LAYER, AND A SEMITRANSPARENT LAYER OF A METAL SELECTED FROM THE GROUP CONSISTING OF SILVER AND ALUMINUM, SAID SEMITRANSPARENT LAYER BEING DEPOSITED ON SAID TRANSPARENT LAYER AND HAVING A TRANSMISSION BETWEEN SUBSTANTIALLY 25% AND 65%.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-04-01 | 1955-10-01 | 1956-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-04-01 | 1959-10-01 | 1960-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-04-01 | 1963-10-01 | 1964-04-01 | $7700.00 | Window Closed / Lapsed |