US2451044A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Communication system employing pulse code modulation
Assignee: AT&T Inc
•
Filing: 1945-07-09
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Granted: 1948-10-12
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Expires: 1965-07-09
Abstract
No abstract record available.
Inventors
- 👤 John R Pierce
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 23:51
CPC Classifications
H; H04; H04B; H04B14/00; H04B14/02; H04B14/04; H04B14/046
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2172354A
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US2262838A
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US2272070A
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US2313209A
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US2326515A
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US2300999A
Cited
US2405231A
Cited
US2418116A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1951-10-12 | 1952-04-12 | 1952-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-10-12 | 1956-04-12 | 1956-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-10-12 | 1960-04-12 | 1960-10-12 | $7700.00 | Window Closed / Lapsed |