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US3403223A
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US
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Microphone combinations of the kind comprising a plurality of directional sound units
Assignee: Koninklijke Philips NV
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Filing: 1965-05-18
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Granted: 1968-09-24
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Expires: 1985-05-18
Abstract
No abstract record available.
Inventors
- 👤 Kleis Derk
- 👤 Hermanus Iding Wilhelmus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 04:05
CPC Classifications
H; H04; H04R; H04R3/00; H04R3/12; H04R1/00; H04R1/20; H04R1/32; H04R1/40; H04R1/406; H04R19/00; H04R19/04; H04R3/005
Claims Analysis
Total Claims: 0
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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) | 1971-09-24 | 1972-03-25 | 1972-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-09-24 | 1976-03-25 | 1976-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-09-24 | 1980-03-25 | 1980-09-24 | $7700.00 | Window Closed / Lapsed |