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EP0488289A2 Expired / Lapsed EP ⏱️ 0.0 years remaining

Video network system

Assignee: Panasonic Holdings Corp
•
Filing: 1991-11-28
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Granted: —
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Expires: 2011-11-28
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Abstract

Abstract A bi-directional video signal transmission system equipped with transmission lines as upsteam and downstream, and they being coupled to each other. With the entire band of a RF signal being taken as a modulation frequency band, an image signal modulated to a frequency band and RF-multiplexed in the upstream is introduced into the downstream at the modulated frequency and then branched to demodulate the same frequency band, thereby obtain one video signal transmission channel. In response to a request by a subscriber, a channel management section assigns and releases the transmission channels and further outputs a control command whereby a transceiver control section performs switching-control of the transmission frequencies to tranceiver units.

Inventors

  • 👤 Akino Inoue
  • 👤 Motohiro Misawa
  • 👤 Kazuaki Yamaguchi
  • 👤 Etsumi Kanaya

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-10-23 21:43
CPC Classifications
H; H04; H04N; H04N7/00; H04N7/14; H04N7/141; H04N7/147

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 211 words
A bi-directional video signal transmission system comprising: transmission line means stretched to have a bus-like configuration for transmitting a RF signal on which an analog video signal is frequency-multiplexed; one-way amplifier means inserted into said transmission line means for amplifying said RF signal; mixing means inserted into said transmission line means for mixing to said RF signal; dividing means inserted into said transmission line means for dividing said RF signal; modulating means for effecting a modulation to a signal having a variable carrier frequency for multiplexing a base-band image signal on said RF signal through said RF signal mixing means; demodulating means for deriving an image signal with a variable carrier frequency from said RF signal distributed by said RF signal dividing means to demodulate it to said base-band image signal; image signal input means for supplying said base-band image signal to said modulating means; image display means for outputting said base-band image signal from said demodulating means; channel management means for assignment of transmission channels for a video signal transmission on said transmission line means over the entire system; transmission request means for requesting a video transmission to said channel management means; and transceiver control means for controlling switching operations of the modulating demodulating in said modulating and demodulating means.
Claim 2
Dependent Claim 33 words
A bi-directional video signal transmission system as claimed in claim 1, wherein said modulating and demodulating means has a switching function for effecting a switching operation between image signals to be inputted thereto.
Claim 3
Dependent Claim 26 words
A bi-directional video signal transmission system as claimed in claim 1, further comprising image signal recording and reproducing means coupled to said modulating and demodulating means.
Claim 4
Dependent Claim 45 words
A bi-directional video signal transmission system as claimed in claim 1, wherein said modulating and demodulating means is coupled to an external network through coding and decoding means for coding and decoding an image signal and further through an interface apparatus comprising a data-multiplexing unit.

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