Patent US2456375A successfully refreshed from Google Patents.
US3204031A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Moving-coil microphone arrangement
Assignee: AKG Acoustics GmbH
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Filing: 1961-08-29
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Granted: 1965-08-31
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Expires: 1981-08-29
Abstract
No abstract record available.
Inventors
- 👤 Gorike Rudolf
- 👤 Schuster Karl
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:01
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/22; H04R1/26; H04R1/265; H04R1/32; H04R1/34; H04R1/38
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
124 words
A MICROPHONE ARRANGEMENT COMPRISING AT LEAST TWO MECHINICALLY INDEPENDENT DIRECTIONAL MOVING-COIL MICROPHONES SEPARATES FROM EACH OTHER BY A FRACTION OF A WAVELENGTH AT A PREDETERMINED ACOUSTIC FREQUENCY, EACH OF SAID MICROPHONES HAVING A HOUSING WITH AN OPEN FRONT END AND A PARTLY OPEN REAR END, EACH OF SAID MICROPHONES FURTHER HAVING A VIBRATORY SYSTEM IN SAID HOUSING INCLUDING AN EXPOSED DIAPHRAGM SPANNING SAID FRONT END AND AN AIR MASS ADJACENT THE REAR SURFACE OF SAID DIAPHRAGM, SAID DIAPHRAGMS FACING IN THE SAME DIRECTION, THE VIBRATORY SYSTEM OF ONE OF SAID MICROPHONES HAVING A NATURAL FREQUENCY ABOVE SAID PREDETERMINED FREQUENCY, THE VIBRATORY SYSTEM OF THE OTHER OF SAID MICROPHONES HAVING A NATURAL FREQUENCY BELOW SAID PREDETERMINED FREQUENCY, AND A COMMON OUTPUT CIRCUIT FOR SAID MIRCOPHONES.
Claim 2
Dependent Claim
124 words
A MICROPHONE ARRANGEMENT COMPRISING AT LEAST TWO MECHINICALLY INDEPENDENT DIRECTIONAL MOVING-COIL MICROPHONES SEPARATES FROM EACH OTHER BY A FRACTION OF A WAVELENGTH AT A PREDETERMINED ACOUSTIC FREQUENCY, EACH OF SAID MICROPHONES HAVING A HOUSING WITH AN OPEN FRONT END AND A PARTLY OPEN REAR END, EACH OF SAID MICROPHONES FURTHER HAVING A VIBRATORY SYSTEM IN SAID HOUSING INCLUDING AN EXPOSED DIAPHRAGM SPANNING SAID FRONT END AND AN AIR MASS ADJACENT THE REAR SURFACE OF SAID DIAPHRAGM, SAID DIAPHRAGMS FACING IN THE SAME DIRECTION, THE VIBRATORY SYSTEM OF ONE OF SAID MICROPHONES HAVING A NATURAL FREQUENCY ABOVE SAID PREDETERMINED FREQUENCY, THE VIBRATORY SYSTEM OF THE OTHER OF SAID MICROPHONES HAVING A NATURAL FREQUENCY BELOW SAID PREDETERMINED FREQUENCY, AND A COMMON OUTPUT CIRCUIT FOR SAID MIRCOPHONES.
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) | 1968-08-30 | 1969-03-01 | 1969-08-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-08-30 | 1973-03-01 | 1973-08-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-08-30 | 1977-03-01 | 1977-08-31 | $7700.00 | Window Closed / Lapsed |