Patent US3225142A successfully refreshed from Google Patents.
US3225142A
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Assignee: AT&T Inc
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Filing: 1961-12-18
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Granted: 1965-12-21
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Expires: 1981-12-18
Abstract
No abstract record available.
Inventors
- 👤 Manfred R Schroeder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 06:18
CPC Classifications
H; H04; H04K; H04K1/00; H04K1/02; H04L; H04L9/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
76 words
APPARATUS FOR SCRAMBLING A MESSAGE SIGNAL TO RENDER IT UNINTELLIGIBLE TO AN UNAUTHORIZED RECIPIENT WHICH COMPRISES, MEANS AT A TRANSMITTER STATION FOR ADDING A SEQUENCE OF VARIOUSLY DELAYED REPLICAS OF A MESSAGE SIGNAL TO THE MESSAGE SIGNAL TO FORM A COMPOSITE SIGNAL MEANS FOR TRANSMITTING SAID COMPOSITE SIGNAL IN ANALOG FORM TO A RECIVER STATION, AND AT THE RECEIVER STATION, MEANS FOR CANCELING THE DELAY REPLICAS OF THE RECEIVED COMPOSITE SIGNAL TO RECONSTITUTE SAID MESSAGE SIGNAL.
Claim 2
Dependent Claim
76 words
APPARATUS FOR SCRAMBLING A MESSAGE SIGNAL TO RENDER IT UNINTELLIGIBLE TO AN UNAUTHORIZED RECIPIENT WHICH COMPRISES, MEANS AT A TRANSMITTER STATION FOR ADDING A SEQUENCE OF VARIOUSLY DELAYED REPLICAS OF A MESSAGE SIGNAL TO THE MESSAGE SIGNAL TO FORM A COMPOSITE SIGNAL MEANS FOR TRANSMITTING SAID COMPOSITE SIGNAL IN ANALOG FORM TO A RECIVER STATION, AND AT THE RECEIVER STATION, MEANS FOR CANCELING THE DELAY REPLICAS OF THE RECEIVED COMPOSITE SIGNAL TO RECONSTITUTE SAID MESSAGE SIGNAL.
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) | 1968-12-20 | 1969-06-21 | 1969-12-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-12-20 | 1973-06-21 | 1973-12-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-12-20 | 1977-06-21 | 1977-12-21 | $7700.00 | Window Closed / Lapsed |