Patent US3087994A successfully refreshed from Google Patents.
US3087994A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Arrangement for the stereophonic reproduction of signals
Assignee: US Philips Corp
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Filing: 1960-03-21
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Granted: 1963-04-30
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Expires: 1980-03-21
Abstract
No abstract record available.
Inventors
- 👤 Schutte Rudolf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:29
CPC Classifications
H; H04; H04H; H04H20/00; H04H20/86; H04H20/88; H03; H03D; H03D1/00; H03D1/22; H03D1/2209; H03D1/2218; H04R; H04R5/00; H04R5/04; H04S; H04S1/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
114 words
A CIRCUIT FOR THE STEREOPHONIC REPRODUCTION OF SIGNALS OF THE TYPE HAVING A SUM SIGNAL OF FIRST AND SECOND COHERENT STEREOPHONIC SIGNALS, AND A DIFFERENCE SIGNAL OF SAID FIRST AND SECOND SIGNALS, SAID DIFFERENCE SIGNAL BEING IN THE FORM OF AMPLITUDE MODULATION OF A SUBCARRIER, SAID CIRCUIT COMPRISING FIRST AND SECOND AMPLITUDE DETECTOR CIRCUITS COMPRISING FIRST AND SECOND UNIDIRECTIONAL CURRENT DEVICES RESPECTIVELY, MEANS APPLYING SAID SUM AND DIFFERENCE SIGNALS TO SAID FIRST AND SECOND AMPLITUDE DETECTOR CIRCUITS, SAID FIRST AND SECOND UNIDIRECTIONAL CURRENT DEVICES BEING CONNECTED WITH OPPOSITE POLARITIES WITH RESPECT TO SAID SUM SIGNAL, AND MEANS CONNECTED TO SAID FIRST AND SECOND DETECTOR CIRCUITS TO DERIVE FIRST AND SECOND STEREOPHONIC OUTPUT SIGNALS RESPECTIVELY.
Claim 2
Dependent Claim
114 words
A CIRCUIT FOR THE STEREOPHONIC REPRODUCTION OF SIGNALS OF THE TYPE HAVING A SUM SIGNAL OF FIRST AND SECOND COHERENT STEREOPHONIC SIGNALS, AND A DIFFERENCE SIGNAL OF SAID FIRST AND SECOND SIGNALS, SAID DIFFERENCE SIGNAL BEING IN THE FORM OF AMPLITUDE MODULATION OF A SUBCARRIER, SAID CIRCUIT COMPRISING FIRST AND SECOND AMPLITUDE DETECTOR CIRCUITS COMPRISING FIRST AND SECOND UNIDIRECTIONAL CURRENT DEVICES RESPECTIVELY, MEANS APPLYING SAID SUM AND DIFFERENCE SIGNALS TO SAID FIRST AND SECOND AMPLITUDE DETECTOR CIRCUITS, SAID FIRST AND SECOND UNIDIRECTIONAL CURRENT DEVICES BEING CONNECTED WITH OPPOSITE POLARITIES WITH RESPECT TO SAID SUM SIGNAL, AND MEANS CONNECTED TO SAID FIRST AND SECOND DETECTOR CIRCUITS TO DERIVE FIRST AND SECOND STEREOPHONIC OUTPUT SIGNALS RESPECTIVELY.
References Cited (Backward Citations)
US2698379A
Cited
US2851532A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1966-04-29 | 1966-10-29 | 1967-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-04-29 | 1970-10-29 | 1971-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-04-29 | 1974-10-29 | 1975-04-30 | $7700.00 | Window Closed / Lapsed |