Patent US2801281A successfully refreshed from Google Patents.
US2801281A
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US
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Communication system employing pulse code modulation
Assignee: AT&T Inc
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Filing: 1952-09-17
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Granted: 1957-07-30
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Expires: 1972-09-17
Abstract
No abstract record available.
Inventors
- 👤 Bernard M Oliver
- 👤 Claude E Shannon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:34
CPC Classifications
H; H03; H03M; H03M1/00; H03M1/12; H03M1/22
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1613686A
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US2326584A
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US2430139A
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US2398490A
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US2449467A
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US2438908A
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US2451044A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-07-29 | 1961-01-28 | 1961-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-07-29 | 1965-01-28 | 1965-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-07-29 | 1969-01-28 | 1969-07-30 | $7700.00 | Window Closed / Lapsed |