Patent US3585121A successfully refreshed from Google Patents.
US3585121A
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Diffraction gratings
Assignee: NAT RES DEV
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Filing: 1968-11-14
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Granted: 1971-06-15
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Expires: 1988-11-14
Abstract
Abstract A METHOD OF MAKING DIFFRACTION GRATINGS, PARTICULARLY X-RAY DIFFRACTION GRATINGS, IN WHICH THOSE PARTS OF THE GRATING THAT FORM THE BOTTOMS OF DIFFRACTING GROOVES BELOW THE GENERAL OPTICALLY SMOOTH SURFACE OF THE GRATING ARE SUBJECTED TO AN ELECTRICAL ETCHING PROCESS.
Inventors
- 👤 Albert Franks
- 👤 Kevin Lindsey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:55
CPC Classifications
G; G21; G21K; G21K1/00; G21K1/06; G02; G02B; G02B5/00; G02B5/18; G02B5/1838; G02B5/1847; G02B5/1857; G21K2201/00; G21K2201/06; G21K2201/067
Claims Analysis
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References Cited (Backward Citations)
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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) | 1974-06-14 | 1974-12-14 | 1975-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-14 | 1978-12-14 | 1979-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-14 | 1982-12-14 | 1983-06-15 | $7700.00 | Window Closed / Lapsed |