| 摘要 |
PURPOSE:To obtain a centralized looking and listening control method of CATV system whose overall constitution can be miniaturized in terms of a distribution system of the outdoor installation corresponding to plural terminals by inserting scramble signals in terms of time division corresponding to each channel. CONSTITUTION:A television signal and a data signal are separated from signals branched from a trunk line 21 in a data separation unit 28, and the data signal is demodulated by a demodulator 29, and inputted to a microprocessor 30, which stores the data in an ROM31 and acts according to the inputted data. A disturbing signal (scramble signal) is produced from a PLL circuit 32, and inputted to a subscriber unit 33 corresponding to each subscribing family. Then a disturbing signal which is controlled by said subscriber unit and produced in correspondence to each channel is coupled with the television signal separated by the data separation unit 28, and transmitted to each family. |
