| 摘要 |
PURPOSE:To forbid copying under certain restrictions by recording additionally a prescribed index signal when an information source is recorded and forbidding the recording of a recording signal when this index signal is detected at the time of copying. CONSTITUTION:An input signal including a restriction flag is supplied from an input terminal 11 to a detection and decision circuit 12 and a combiner 13. The circuit 12 detects the restriction flag out of the input signal, and when the restriction flag is 0 (restricted), the input signal is added with an identification signal in the combiner 13. Then, a signal for recording, which is accompanied by the identification signal is led to an output terminal 15 and recorded onto a recording medium by a recording circuit. In case of the input signal which has already been accompanied by the identification signal in the above- stated method, this matter is detected by an identification signal detecting circuit 21 and then given to a sound recording forbidding circuit 22. The circuit 22 forbids the sound recording when the identification signal is detected by the circuit 21. By this method, further copying from a copied tape can thus be prevented. |
