Patent US2981826A successfully refreshed from Google Patents.
US2981826A
Expired / Lapsed
US
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Light equalizing device
Assignee: Individual
•
Filing: 1959-10-27
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Granted: 1961-04-25
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Expires: 1979-10-27
Abstract
No abstract record available.
Inventors
- 👤 Mattern John
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:13
CPC Classifications
H; H04; H04B; H04B10/00; H04B10/25; H04B10/2507; G; G01; G01N; G01N21/00; G01N21/17; G01N21/25; G01N21/255; G02; G02B; G02B6/00; G02B6/24; G02B6/26; G02B6/28; G02B6/2804; G02B6/2808
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1800277A
Cited
GB285738A
Cited
US1706161A
Cited
US1965865A
Cited
US2196166A
Cited
US2448244A
Cited
US2640144A
Cited
US2825260A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-04-24 | 1964-10-24 | 1965-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-04-24 | 1968-10-24 | 1969-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-04-24 | 1972-10-24 | 1973-04-25 | $7700.00 | Window Closed / Lapsed |