US3706040A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wired broadcasting systems with phantom circuit supplying control current on program signal wires
Assignee: Communications Patents Ltd
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Filing: 1970-05-21
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Granted: 1972-12-12
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Expires: 1990-05-21
Abstract
Abstract A WIRED TELEVISION SYSTEM PROVIDES FOR TWO BALANCED CONDUCTOR PAIRS CONNECTED BETWEEN SUBSCRIBERS AND A CENTRAL STATION WITH A PLURALITY OF SIGNAL HIGHWAY ROUTES. ONE CONDUCTOR PAIR PASSES THE TELEVISION SIGNALS AND A CONTROL VOLTAGE WHICH IS INTERRUPTED BY A DIAL AT THE SUBSCRIBER STATION TO SCAN A STEPPING SWITCH AT THE CENTRAL STATION AND MAKE A SELECTION OR TO RETURN TO A DATUM POSITION. AUXILIARY SIGNALS MAY BE PASSED ALONG THE SECOND PAIR OF CONDUCTORS. EACH PROGRAM EXCHANGE INCLUDES IMPEDANCE MATCHING NETWORKS AND ILTERS TO PROVIDE BALANCED SIGNALS AND TO PROCESS LOW FREQUENCY AUDIO AND HIGH FREQUENCY TELEVISION SIGNALS.
Inventors
- 👤 Eric J Gargini
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 04:46
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/16; H04N7/173; H04N7/17345; H04N2007/1739
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) | 1975-12-12 | 1976-06-12 | 1976-12-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-12 | 1980-06-12 | 1980-12-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-12 | 1984-06-12 | 1984-12-12 | $7700.00 | Window Closed / Lapsed |