US2425399A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for measuring the index of refraction of thin layers of transparent material
Assignee: RCA Corp
•
Filing: 1943-06-17
•
Granted: 1947-08-12
•
Expires: 1963-06-17
Abstract
No abstract record available.
Inventors
- 👤 Lawrence T Sachtleben
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:21
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/17; G01N21/41; G01N21/43
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-08-11 | 1951-02-10 | 1951-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-08-11 | 1955-02-10 | 1955-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-08-11 | 1959-02-10 | 1959-08-12 | $7700.00 | Window Closed / Lapsed |