System for transmitting a commercial program in a CATV system
First Claim
1. In a system for transmitting television signals in a CATV system wherein a television signal of a priority channel is selectively scrambled with an encoding at a broadcasting station to produce in the priority channel 1) a scrambled television signal for terminal devices of subscribers and 2) non-scrambled television signal for non-subscribers used for transmitting a commercial program, the scrambled and non-scrambled television signals are alternately transmitted from the broadcasting station to a local center in the priority channel, and the scrambled television signal is descrambled at the local center, the descrambled television signal is re-scrambled by an encoder with another encoding at the local center, the re-scrambled television signal and the non-scrambled television signal are alternately transmitted to terminal devices wherein the system comprises:
- detector means, provided in the local center, for detecting said scrambled television signal and said non-scrambled television signal in the priority channel and said detector means for producing a scrambled signal and a non-scrambled signal in accordance with said detected signals;
switching means, responsive to said scrambled signal, for feeding said descrambled television signal to said encoder for re-scrambling said television signal, and responsive to said non-scrambled signal for passing said non-scrambled television signal without passing through said encoder; and
transmitting means for alternately transmitting said re-scrambled television signal and said non-scrambled television signal to subscriber and non-subscriber terminal devices.
1 Assignment
0 Petitions
Accused Products
Abstract
A CATV system includes a broadcasting station, a satellite, and a local center. Scrambled television signals transmitted from the broadcasting station to the local center through the satellite are descrambled and re-scrambled at the local center, and the re-scrambled TV signals are transmitted to terminal devices. A non-scrambled TV signal included in the TV signal transmitted from the broadcasting station to the local center is detected. The detected non-scrambled TV signal is transmitted to terminal devices without scrambling.
115 Citations
8 Claims
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1. In a system for transmitting television signals in a CATV system wherein a television signal of a priority channel is selectively scrambled with an encoding at a broadcasting station to produce in the priority channel 1) a scrambled television signal for terminal devices of subscribers and 2) non-scrambled television signal for non-subscribers used for transmitting a commercial program, the scrambled and non-scrambled television signals are alternately transmitted from the broadcasting station to a local center in the priority channel, and the scrambled television signal is descrambled at the local center, the descrambled television signal is re-scrambled by an encoder with another encoding at the local center, the re-scrambled television signal and the non-scrambled television signal are alternately transmitted to terminal devices wherein the system comprises:
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detector means, provided in the local center, for detecting said scrambled television signal and said non-scrambled television signal in the priority channel and said detector means for producing a scrambled signal and a non-scrambled signal in accordance with said detected signals; switching means, responsive to said scrambled signal, for feeding said descrambled television signal to said encoder for re-scrambling said television signal, and responsive to said non-scrambled signal for passing said non-scrambled television signal without passing through said encoder; and transmitting means for alternately transmitting said re-scrambled television signal and said non-scrambled television signal to subscriber and non-subscriber terminal devices. - View Dependent Claims (2, 3, 4, 5)
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6. A system for a local center to which 1) scrambled television signals through a plurality of priority channels of respective scrambling systems and 2) non-scrambled television signals through said plurality of priority channels are applied from broadcasting stations, wherein said scrambled television signal and the non-scrambled television signal of each priority channel are alternately transmitted, and the scrambled television signals are re-scrambled with a re-scrambling system at the local center, the system comprising:
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detector means for detecting each of the scrambled television signals and for producing a scramble signal when detected; descrambling means for descrambling the scrambled television signal; re-scrambling means for re-scrambling the descrambled television signals with a re-scrambling system; and transmitting means for transmitting the re-scrambled television signal to a plurality of terminal devices. - View Dependent Claims (7, 8)
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Specification