| 摘要 |
PURPOSE:To use the circuit of a demodulation system for a digital signal in common by generating a read clock to read storage information from a memory in synchronizing with a fixed reference signal at CD reproduction and in synchronizing with a regenerated clock signal at LDD reproduction. CONSTITUTION:A changeover switch 17 switched depending on the kind of a reproducing disc is provided in a digital information demodulation system 14, and the switch 17 is thrown to the position (a) at LDD and thrown to the position (B) and CD based on the disc information from a disc discrimination circuit 10. The high frequency band of the frequency characteristic is compensated especially by an equalizer 18 in the PCM audio information at CD reproduction. On the other hand, in case of LDD, the PCM audio information included in a reproduced RF signal is extracted by an LPF 19 together with the FM audio information and the FM video information and fed to a de-emphasis circuit 20. The compensation recording is executed. Thus, the S/N of the digital signal is improved to a low frequency noise at recording and reproduction. |
