US2641963A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for increasing contrast of transparencies
Assignee: Individual
•
Filing: 1950-11-16
•
Granted: 1953-06-16
•
Expires: 1970-11-16
Abstract
No abstract record available.
Inventors
- 👤 Stanley R Carter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:20
CPC Classifications
G; G02; G02B; G02B27/00; G02B27/28
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1740673A
Cited
US2014688A
Cited
US2131501A
Cited
US2158129A
Cited
US2318705A
Cited
US2501446A
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 |