US3370294A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Communications echo suppression
Assignee: Individual
•
Filing: 1964-05-13
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Granted: 1968-02-20
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Expires: 1984-05-13
Abstract
No abstract record available.
Inventors
- 👤 Leonard R Kahn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 16:38
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/20; H04B3/21
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
180 words
IN A TWO-WAY SPEECH COMMUNICATIONS SYSTEM INVOLVING SUBSTANTIAL TRANSMISSION TIMES BETWEEN COMMUNICATIONS TERMINALS, AND WHEREIN RESPECTIVE SIGNAL TRANSMISSION AND SIGNAL RECEIVING PATHS ARE ASSOCIATED WITH SAID COMMUNICATIONS TERMINALS WITH SUCH RESPECTIVE SIGNAL PATHS BEING NOMINALLY ISOLATED FROM EACH OTHER BY RESPECTIVE HYBRID COILS IN CIRCUIT WITH SAID TERMINALS, THE IMPROVEMENT IN ECHO SUPPRESSION CIRCUITRY, COMPRISING; SIGNAL LEVEL RESPONSIVE SWITCHING MEANS ASSOCIATED WITH EACH SAID TERMINAL ESTABLISHING ITS SIGNAL PATH IN A TRANSMIT CONDITION WHEN THE SIGNAL GENERATED AT SAID TERMINAL IS STRONGER THAN THE SIGNAL RECEIVED AT SAID TERMINAL AND IN A RECEIVE CONDITION WHEN SUCH RECEIVED SIGNAL IS THE STRONGER, EACH SAID SIGNAL PATH IS ITS TRANSMIT CONDITION AT ALL TIMES INCLUDING SIGNAL PASSBAND LIMITING MEANS PASSING FROM ABOUT 80% TO ABOUT 95% OF THE FREQUENCY COMPONENTS OF THE SPEECH SIGNAL APPLIED THERETO AND BLOCKING THE BALANCE OF THE APPLIED SIGNAL FREQUENCY COMPONENTS, AND EACH SAID SIGNAL PATH IN ITS RECEIVE CONDITION AT ALL TIMES INCLUDING PASSBAND LIMITING MEANS PASSING ABOUT 20% TO ABOUT 5% OF THE FREQUENCY COMPONENTS OF THE SPEECH SIGNAL APPLIED THERETO AND BLOCKING THE BALANCE
Claim 2
Dependent Claim
180 words
IN A TWO-WAY SPEECH COMMUNICATIONS SYSTEM INVOLVING SUBSTANTIAL TRANSMISSION TIMES BETWEEN COMMUNICATIONS TERMINALS, AND WHEREIN RESPECTIVE SIGNAL TRANSMISSION AND SIGNAL RECEIVING PATHS ARE ASSOCIATED WITH SAID COMMUNICATIONS TERMINALS WITH SUCH RESPECTIVE SIGNAL PATHS BEING NOMINALLY ISOLATED FROM EACH OTHER BY RESPECTIVE HYBRID COILS IN CIRCUIT WITH SAID TERMINALS, THE IMPROVEMENT IN ECHO SUPPRESSION CIRCUITRY, COMPRISING; SIGNAL LEVEL RESPONSIVE SWITCHING MEANS ASSOCIATED WITH EACH SAID TERMINAL ESTABLISHING ITS SIGNAL PATH IN A TRANSMIT CONDITION WHEN THE SIGNAL GENERATED AT SAID TERMINAL IS STRONGER THAN THE SIGNAL RECEIVED AT SAID TERMINAL AND IN A RECEIVE CONDITION WHEN SUCH RECEIVED SIGNAL IS THE STRONGER, EACH SAID SIGNAL PATH IS ITS TRANSMIT CONDITION AT ALL TIMES INCLUDING SIGNAL PASSBAND LIMITING MEANS PASSING FROM ABOUT 80% TO ABOUT 95% OF THE FREQUENCY COMPONENTS OF THE SPEECH SIGNAL APPLIED THERETO AND BLOCKING THE BALANCE OF THE APPLIED SIGNAL FREQUENCY COMPONENTS, AND EACH SAID SIGNAL PATH IN ITS RECEIVE CONDITION AT ALL TIMES INCLUDING PASSBAND LIMITING MEANS PASSING ABOUT 20% TO ABOUT 5% OF THE FREQUENCY COMPONENTS OF THE SPEECH SIGNAL APPLIED THERETO AND BLOCKING THE BALANCE
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) | 1971-02-19 | 1971-08-21 | 1972-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-02-19 | 1975-08-21 | 1976-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-02-19 | 1979-08-21 | 1980-02-20 | $7700.00 | Window Closed / Lapsed |