Patent US1281482A successfully refreshed from Google Patents.
Patent US3678207A successfully refreshed from Google Patents.
US3678207A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit arrangement for telephone private branch exchanges permitting conference calls between subscriber sets having video transmission capabilities
Assignee: Siemens AG
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Filing: 1970-06-18
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Granted: 1972-07-18
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Expires: 1990-06-18
Abstract
Abstract A circuit arrangement is described for permitting conference calls between subscriber stations in a telephone private branch exchange wherein said subscriber stations, or at least a portion of them are equipped to transmit and receive video signals. When the conference call is initiated, the video receivers of the calling subscriber and the called subscribers are connected to a transmission line. At the initiation of the call, only the video transmitting means of the calling subscriber is connected to a second transmission line. The latter two transmission lines are electrically connected by means of an amplifier. Each of the called subscribers are connected to said first transmission line only by their video receiving means. Each of the called subscriber sets is equipped with a means by which the subscriber transmitting video can be disconnected from the line, and the subscriber actuating said means can connect his video transmitting means to the line. The switching means utilized will permit only one video transmitter to be connected to the line at any given time.
Inventors
- 👤 Siegfried Schon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:05
CPC Classifications
H; H04; H04M; H04M3/00; H04M3/42; H04M3/56; H04N; H04N7/00; H04N7/14; H04N7/15
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
241 words
A circuit arrangement for permitting conference calls among subscribers in a private branch telephone exchange or the like wherein certain of the subscriber stations include means for transmitting and means for receiving video signals, comprising: means for initiating a conference call at each said subscriber station, first transmission line means for interconnecting said subscriber stations, first switching means in each of said subscriber stations operable in response to operation of one of said initiating means for connecting said video receiving means of predetermined ones of said subscriber stations to said first transmission line means, said predetermined ones of said subscriber stations being selected by said initiating means, second transmission line means electrically connected to said first transmission line means, connecting switch means at each said subscriber station operable to cause the connection of the video transmitter therein to said second transmission line means, second switching means in each said subscriber station for connecting the video transmitter means therein to said second transmission line means, one of said second switching means being rendered operable by the actuation of the said connecting switch means associated therewith, and third switching means for disconnecting the one of said second switching means previously operated upon receipt of connection demand signal from another of said subscriber stations via the connecting switch means therein and for permitting the second switching means of said other subscriber station to connect the video transmitter therein to said second transmission line means.
Claim 2
Dependent Claim
241 words
A circuit arrangement for permitting conference calls among subscribers in a private branch telephone exchange or the like wherein certain of the subscriber stations include means for transmitting and means for receiving video signals, comprising: means for initiating a conference call at each said subscriber station, first transmission line means for interconnecting said subscriber stations, first switching means in each of said subscriber stations operable in response to operation of one of said initiating means for connecting said video receiving means of predetermined ones of said subscriber stations to said first transmission line means, said predetermined ones of said subscriber stations being selected by said initiating means, second transmission line means electrically connected to said first transmission line means, connecting switch means at each said subscriber station operable to cause the connection of the video transmitter therein to said second transmission line means, second switching means in each said subscriber station for connecting the video transmitter means therein to said second transmission line means, one of said second switching means being rendered operable by the actuation of the said connecting switch means associated therewith, and third switching means for disconnecting the one of said second switching means previously operated upon receipt of connection demand signal from another of said subscriber stations via the connecting switch means therein and for permitting the second switching means of said other subscriber station to connect the video transmitter therein to said second transmission line means.
Claim 3
Dependent Claim
19 words
The circuit arrangement defined in claim 1 wherein each said connecting switch means includes a manually operable switch means.
Claim 4
Dependent Claim
95 words
The circuit arrangement defined in claim 1 wherein said third switching means comprises a switch element connected in series with a holding circuit for said second switching means, said switch element being in a first condition closing said holding circuit when one of said second switching means is operative and in a second condition opening said circuit when another of said second switching means is rendered operative, said other second switching means being maintained in an operative condition by continued actuation of said connecting switch means until said switch element returns to said first condition.
References Cited (Backward Citations)
US3519744A
Cited
GB1213763A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-18 | 1976-01-17 | 1976-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-18 | 1980-01-17 | 1980-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-18 | 1984-01-17 | 1984-07-18 | $7700.00 | Window Closed / Lapsed |