US3588382A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Directional electret transducer
Assignee: Nortel Networks Ltd
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Filing: 1967-10-13
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Granted: 1971-06-28
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Expires: 1987-10-13
Abstract
Abstract AN ELECTROACOUSTIC ELECTRET TRANSDUCER WHICH EXHIBITS DIRECTIONAL RESPONSE CHARACTERISTICS RESULTING FROM AN ELECTRICAL INTERACTION BETWEEN AT LEAST TWO DISCRETE PREPOLARIZED VOLUMES WITHIN AN ELECTRET, THE VOLUMES HAVING OPPOSITELY POLED DIPOLE MOMENT VECTORS.
Inventors
- 👤 Cornelis W Reedyk
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:16
CPC Classifications
H; H04; H04R; H04R1/00; H04R1/20; H04R1/32; H04R1/326; H01; H01G; H01G7/00; H01G7/02; H04R19/00; H04R19/01; H04R19/016
Claims Analysis
Total Claims: 0
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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) | 1974-06-27 | 1974-12-27 | 1975-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-27 | 1978-12-27 | 1979-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-27 | 1982-12-27 | 1983-06-28 | $7700.00 | Window Closed / Lapsed |