| 摘要 |
PURPOSE:To record and reproduce securely a teletext signal by replacing a video signal with memory information of a memory circuit so as to be a composite signal, then recording it and reproducing and outputting selectively a teletext broadcast section where the drop-out will not occur at reproduction. CONSTITUTION:A reproduction video signal A inputted from an input terminal 6 is transmitted to a control circuit 9, memory circuit 7 and switch 10. On the other hand, a dropout signal B is inputted to the circuit 9 from a terminal 11, and produced when a reproduction envelope drops to an extremely low level. The circuit 9 generates a control signal C, muting signal D and switch signal E, which are used for controlling the circuit 7, muting circuit 8 and switch 10. Memory information in the circuit 7 is transmitted to an output terminal 12 through the circuit 8 and switch 10, replaced with the signal A and synthesized, thereby obtaining an output signal F. |
