Patent US4737380A successfully refreshed from Google Patents.
US2929923A
Expired / Lapsed
US
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Light modulation device
Assignee: Sprague Electric Co
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Filing: 1954-08-19
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Granted: 1960-03-22
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Expires: 1974-08-19
Abstract
No abstract record available.
Inventors
- 👤 Lehovec Kurt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:42
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/015
Claims Analysis
Total Claims: 0
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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) | 1963-03-22 | 1963-09-21 | 1964-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-03-22 | 1967-09-21 | 1968-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-03-22 | 1971-09-21 | 1972-03-22 | $7700.00 | Window Closed / Lapsed |