| 摘要 |
PURPOSE:To provide a generator and receiver for a composite video signal in which a picture signal comprising a video signal and a transmission control signal is scrambled with a simplified circuit. CONSTITUTION:A pseudo random pulse generator is realized by feeding back outputs D3, D10 of a shift register 91 using a field pulse as a clock signal via an exclusive logic circuit 92 and the random pulse pattern is fed to a code conversion circuit 94 via an AND gate group 93. A control signal (transmission control signal) whose bit numbers are 1 to 10 outputted from a signal separator circuit 17 at a receiver side is subject to self-scramble by said code conversion circuit 94. When a signal of a level 1 is inputted to an external terminal TS, the self-scramble is stopped and a normal image pattern is observed. However, when the signal is scrambled at a sender side, the descramble circuit to descramble the scrambled signal is formed. |
