US2698379A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transmission system for stereophonic signals
Assignee: Koninklijke Philips NV
•
Filing: 1952-04-03
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Granted: 1954-12-28
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Expires: 1972-04-03
Abstract
No abstract record available.
Inventors
- 👤 Willem W Boelens
- 👤 van Zelst Johannes J Zaalberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:51
CPC Classifications
H; H04; H04H; H04H20/00; H04H20/86; H04H20/88; H04J; H04J1/00; H04S; H04S1/00; H04S1/002
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1666158A
Cited
GB540185A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-12-27 | 1958-06-28 | 1958-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-12-27 | 1962-06-28 | 1962-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-12-27 | 1966-06-28 | 1966-12-28 | $7700.00 | Window Closed / Lapsed |