US3128449A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Error detecting and correcting system
Assignee: AT&T Inc
•
Filing: 1960-06-14
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Granted: 1964-04-07
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Expires: 1980-06-14
Abstract
No abstract record available.
Inventors
- 👤 Douglas B Armstrong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:20
CPC Classifications
H; H03; H03M; H03M13/00; H03M13/03; H03M13/05; H03M13/13; H03M13/19
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USRE23601E
Cited
US2904781A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1967-04-07 | 1967-10-07 | 1968-04-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1971-04-07 | 1971-10-07 | 1972-04-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1975-04-07 | 1975-10-07 | 1976-04-07 | $7700.00 | Window Closed / Lapsed |