| 摘要 |
PURPOSE:To provide a method of generating a dubbing prevention signal by which illegal dubbing is effectively prevented without affecting a displayed video signal. CONSTITUTION:In this method of generating a dubbing prevention signal, a dubbing prevention signal DP whose level is higher than a maximum amplitude of a video signal and being pulses without any harmonic component is added to the video signal. Since the video signal recorder adjusts the amplitude of the video signal based on the dubbing prevention signal DP, the amplitude of the video signal is substantially compressed and the picture subject to dubbing is dark. Smear is less by adopting a pulse waveform without any harmonic component such as sinusoidal pulse waveform for the dubbing prevention signal DP. |
