| 摘要 |
PURPOSE:To record and reproduce a digital sound signal of very high tone quality which is obtained by converting a sound analog signal and whose FM carrier frequency is the same as the FM carrier frequency obtained in the case of a conventional system. CONSTITUTION:Sound analog signals inputted from sound input terminals 1 and 2 are respectively converted into digital signals by means of AD converters 3 and 4 and, after digital-modulating the digital signals by adding error correcting codes to the digital signals by means of a pulse code modulator 5 of the next stage, the digital signals are FM-modulated by means of an FM modulator 6. At FM modulation, the FM carrier frequency is selected in such a way that the ''low'' and ''high'' of the digital code signal can coincide with FM carrier frequencies f1 and f2 obtained by conventional systems where sound analog signals are directly FM-modulated and recorded on a video disk. Therefore, conventional problems of occurrence of beat interference between the FM-modulated waves of digitized sound signals and video signals can be dissolved effectively. |
