| 摘要 |
PROBLEM TO BE SOLVED: To provide recording equipment which superposes a copy protect signal on a main audio signal and records them on a recording medium so that unjust cancellation of the copy protect signal be prevented and that the protect signal can be taken out, with the tone quality of the main audio signal prevented from being deteriorated, at the time of just reproduction thereof and to provide reproducing equipment which can control output of the main audio signal in accordance with the copy protect signal reproduced from a recording medium, transmitting equipment which can transmit the signals and the recording medium. SOLUTION: An adder 3 adds up an analog audio signal in an audio band outputted by a sound source 2 and a copy protect signal of a specific frequency, e.g. 16×44.1kHz, in a band being apart sufficiently from the audio band. A 1-bitΣΔconverter 5 converts an addition output of the adder 3 into 1-bit digital data. A record processing circuit 6 applies a recording processing to the 1-bit digital data outputted by the 1-bitΣΔconverter 5. |
