US3183304A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sound amplification system
Assignee: AT&T Inc
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Filing: 1962-03-07
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Granted: 1965-05-11
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Expires: 1982-03-07
Abstract
No abstract record available.
Inventors
- 👤 Manfred R Schroeder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:27
CPC Classifications
H; H04; H04M; H04M9/00; H04M9/08; H04M9/087; H04R; H04R3/00; H04R3/02
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
97 words
IN A SOUND AMPLIFICATION SYSTEM COMPRISING A MICROPHONE, A POWER AMPLIFIER, AND A LOUDSPEAKER, MEANS IN CIRCUIT RELATION WITH SAID MICROPHONE, AMPLIFIER AND LOUDSPEAKER FOR PREVENTING INSTABILITY DUE TO ACOUSTIC FEEDBACK BETWEEN SAID LOUDSPEAKER AND SAID MICROPHONE INCLUDING A FREQUENCY SHIFTER FOR CHANGING THE FREQUENCY OF EACH FREQUENCY COMPONENT IN THE AMPLITUDE SPECTRUM OF AN INCOMING WAVE BY A UNIFORM, PREDETERMINED AMOUNT, TO FORM A FREQUENCY SHIFTED WAVE HAVING AN AMPLITUDE SPECTRUM WITH FREQUENCY COMPONENTS THAT DIFFER FROM THE CORRESPONDING FREQUENCY COMPONENTS OF THE SPECTRUM OF SAID INCOMING WAVE BY SAID PREDETERMINED AMOUNT OF FREQUENCY CHANGE, AND
Claim 2
Dependent Claim
97 words
IN A SOUND AMPLIFICATION SYSTEM COMPRISING A MICROPHONE, A POWER AMPLIFIER, AND A LOUDSPEAKER, MEANS IN CIRCUIT RELATION WITH SAID MICROPHONE, AMPLIFIER AND LOUDSPEAKER FOR PREVENTING INSTABILITY DUE TO ACOUSTIC FEEDBACK BETWEEN SAID LOUDSPEAKER AND SAID MICROPHONE INCLUDING A FREQUENCY SHIFTER FOR CHANGING THE FREQUENCY OF EACH FREQUENCY COMPONENT IN THE AMPLITUDE SPECTRUM OF AN INCOMING WAVE BY A UNIFORM, PREDETERMINED AMOUNT, TO FORM A FREQUENCY SHIFTED WAVE HAVING AN AMPLITUDE SPECTRUM WITH FREQUENCY COMPONENTS THAT DIFFER FROM THE CORRESPONDING FREQUENCY COMPONENTS OF THE SPECTRUM OF SAID INCOMING WAVE BY SAID PREDETERMINED AMOUNT OF FREQUENCY CHANGE, AND
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) | 1968-05-10 | 1968-11-09 | 1969-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-05-10 | 1972-11-09 | 1973-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-05-10 | 1976-11-09 | 1977-05-11 | $7700.00 | Window Closed / Lapsed |