US2641954A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Protective coatings for optical elements and methods for applying them
Assignee: Eastman Kodak Co
•
Filing: 1950-05-06
•
Granted: 1953-06-16
•
Expires: 1970-05-06
Abstract
No abstract record available.
Inventors
- 👤 Philip T Scharf
- 👤 William J Keenan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 07:05
CPC Classifications
C; C03; C03C; C03C17/00; C03C17/34; C03C17/3411; C03C17/3429; C03C17/3447; C03C17/3452
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
91 words
AN OPTICAL ELEMENT COMPRISING A BASE CONSISTING OF UNSTABLE GLASS WHICH DETERIORATES UPON EXPOSURE TO THE ATMOSPHERE, SAID ELEMENT HAVING ALL LIGHT TRANSMITTING SURFACES GROUND, POLISHED AND PROTECTED BY TRANSPARENT SOLID MATERIALS, THE PROTECTIVE MATERIAL ON AT LEAST ONE OF SAID SURFACES CONSISTING OF A LAYER OF SILICON MONOXIDE SUBLIMED ON THE SURFACE IN A VACUUM AT A PRESSURE LESS THAN ONE MICRON HG AND A LAYER OF MAGNESIUM FLOURIDE SUBLIMED ON THE LAYER OF SILICON MONOXIDE IN THE SAME VACUUM AND BEFORE THE LATTER HAS APPRECIALY CHANGED TO SILICON DIOXIDE.
References Cited (Backward Citations)
US1989824A
Cited
US2281474A
Cited
US2331716A
Cited
US2337460A
Cited
US2391595A
Cited
US2432484A
Cited
US2427592A
Cited
US2386875A
Cited
US2432538A
Cited
US2561077A
Cited
US2478385A
Cited
US2456899A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-06-15 | 1956-12-15 | 1957-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-06-15 | 1960-12-15 | 1961-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-06-15 | 1964-12-15 | 1965-06-16 | $7700.00 | Window Closed / Lapsed |