Broadcasting systems with fibre optic transmission lines
DCFirst Claim
1. A broadcasting system conveying signals by a signal path between a central station and a plurality of subscribers, comprising in combination, a common optical fibre in said signal path carrying signals to said plurality of subscribers from said central station, said fibre extending between an electro-optical transducer at said central station producing a light beam and photo-sensitive detector means at a reception position near the subscribers station, transmission means at the central station modulating the light beam for transmission through said optical fibre, said transmission means including modulation means producing a light beam modulated by a high frequency carrier which itself is modulated with video broadcast signals, conventional television receivers at the subscriber stations responsive to receive said high frequency carrier modulated with video broadcast signals, light beam demodulation means at said reception position responsive to said photo-sensitive detector means to convert said light beam into demodulated high frequency carrier radio wave signals modulated with video broadcast signals, and means coupling said demodulated signals from said reception position to said subscriber stations in a form suitable for direct application to said conventional television receivers without further signal processing.
1 Assignment
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Accused Products
Abstract
A wired broadcasting system is provided in which a signal path between a central station and at least some of a plurality of subscribers includes an optical fibre extending between an electro-optical transducer and a photo-sensitive detector. The optical fibre may extend over the whole length of the transmission path between the central station and each of the plurality of subscribers, or the optical fibre may extend between the central station and a distribution point from which signals may be conveyed to a group of subscribers over conductive paths, or an optical fibre may be arranged to extend between each of the plurality of subscribers and a programme selector located at a programme exchange.
123 Citations
5 Claims
- 1. A broadcasting system conveying signals by a signal path between a central station and a plurality of subscribers, comprising in combination, a common optical fibre in said signal path carrying signals to said plurality of subscribers from said central station, said fibre extending between an electro-optical transducer at said central station producing a light beam and photo-sensitive detector means at a reception position near the subscribers station, transmission means at the central station modulating the light beam for transmission through said optical fibre, said transmission means including modulation means producing a light beam modulated by a high frequency carrier which itself is modulated with video broadcast signals, conventional television receivers at the subscriber stations responsive to receive said high frequency carrier modulated with video broadcast signals, light beam demodulation means at said reception position responsive to said photo-sensitive detector means to convert said light beam into demodulated high frequency carrier radio wave signals modulated with video broadcast signals, and means coupling said demodulated signals from said reception position to said subscriber stations in a form suitable for direct application to said conventional television receivers without further signal processing.
Specification