US3281533A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stereophonic sound system
Assignee: Inter Aural Research Inc
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Filing: 1963-09-03
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Granted: 1966-10-25
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Expires: 1983-09-03
Abstract
No abstract record available.
Inventors
- 👤 Ernest J Burrows
- 👤 Maurice R Jackson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:12
CPC Classifications
H; H04; H04S; H04S1/00; H04S1/002; Y; Y10; Y10S; Y10S84/00; Y10S84/01
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
156 words
AN AUDIO REPRODUCTION SYSTEM COMPRISING: A PLURALITY OF ELECTRICAL CIRCUIT EACH HAVING INPUT AND OUTPUT TERMINALS; MEANS FOR APPLYING AUDIO INPUT SIGNALS TO THE INPUT TERMINALS OF SAID CIRCUITS; MEANS FOR SEPARATING A PORTION OF EACH SAID INPUT SIGNALS FROM THE REMAINDER OF SAID INPUT SIGNALS TO PROVIDE SEPARATED SIGNALS CONTAINGING FREQUENCIES ABOVE A LOWER LIMIT FREQUENCY AND INCLUDING A MIDBAND RANGE OF AUDIO FREQUENCIES; MEANS FOR MIXING SAID SEPARATED SIGNALS TOGETHER TO PRODUCE A COMBINED SIGNAL CONTAINING SAID MIDBAND FREQUENCIES; MEANS FOR SUBSTANTIALLY REVERSING THE PHASE OF A PORTION OF SAID COMBINED SIGNAL AND FOR TRANSMITTING THE PHASE REVERSED PORTION OF SAID COMBINED SIGNAL TO THE OUTPUT TERMINAL OF ONE OF SAID CIRCUITS; AND MEANS FOR TRANSMITTING ANOTHER PORTION OF SAID COMBINED SIGNAL TO THE OUTPUT TERMINAL OF ANOTHER OF SAID CIRCUITS, SO THAT THE OUTPUT SIGNALS OF SAID ONE CIRCUIT AND SAID ANOTHER CIRCUIT ARE SUBSTANTIALLY REVERSED IN PHASE IN SAID MIDBAND RANGE FREQUENCIES.
Claim 2
Dependent Claim
156 words
AN AUDIO REPRODUCTION SYSTEM COMPRISING: A PLURALITY OF ELECTRICAL CIRCUIT EACH HAVING INPUT AND OUTPUT TERMINALS; MEANS FOR APPLYING AUDIO INPUT SIGNALS TO THE INPUT TERMINALS OF SAID CIRCUITS; MEANS FOR SEPARATING A PORTION OF EACH SAID INPUT SIGNALS FROM THE REMAINDER OF SAID INPUT SIGNALS TO PROVIDE SEPARATED SIGNALS CONTAINGING FREQUENCIES ABOVE A LOWER LIMIT FREQUENCY AND INCLUDING A MIDBAND RANGE OF AUDIO FREQUENCIES; MEANS FOR MIXING SAID SEPARATED SIGNALS TOGETHER TO PRODUCE A COMBINED SIGNAL CONTAINING SAID MIDBAND FREQUENCIES; MEANS FOR SUBSTANTIALLY REVERSING THE PHASE OF A PORTION OF SAID COMBINED SIGNAL AND FOR TRANSMITTING THE PHASE REVERSED PORTION OF SAID COMBINED SIGNAL TO THE OUTPUT TERMINAL OF ONE OF SAID CIRCUITS; AND MEANS FOR TRANSMITTING ANOTHER PORTION OF SAID COMBINED SIGNAL TO THE OUTPUT TERMINAL OF ANOTHER OF SAID CIRCUITS, SO THAT THE OUTPUT SIGNALS OF SAID ONE CIRCUIT AND SAID ANOTHER CIRCUIT ARE SUBSTANTIALLY REVERSED IN PHASE IN SAID MIDBAND RANGE FREQUENCIES.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-10-24 | 1970-04-25 | 1970-10-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-10-24 | 1974-04-25 | 1974-10-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-10-24 | 1978-04-25 | 1978-10-25 | $7700.00 | Window Closed / Lapsed |