| 摘要 |
1468165 Data transmission system PLESSEY CO Ltd 17 May 1974 [1 June 1973] 26263/73 Heading G1A A data transmission system converts electrical data signals to light signals, transmits the light along on optical transmission line and reconverts it to electrical data signals at the other end of the line. The data signals are preferably analogue television signals. As shown, a LED 1 bonded to a multimode type optical fibre 2, converts the electrical signals to light and reconversion takes place at reversed biased silicon junction device 3. To linearize the system, an optical and electrical feedback path is provided. Detectors 4, 5 pick up light from LED 1 or from fibre 2 and via an index matching medium and the electrical signal from the detectors is amplified and used as negative feedback for the input data signal. Several data signals may be transmitted using frequency multi-plexing, different colour light and corresponding detector filters, or time division multi-plex. |
