| 摘要 |
<p>PURPOSE:To multiplex a required digital voice signal onto the vertical synchronization part of a picture signal by providing a difference pulse code modulation/ pulse code modulation(DPCM/PCM) conversion circuit on a receiver. CONSTITUTION:A digital voice signal is multiplexed onto a picture signal (DPCM picture signal) subjected to the difference pulse code modulation to form a digital signal string and the voice signal is demultiplexed from the picture signal with the receiver. A control signal generating circuit 2 in the receiver outputs a picture voice selection signal (c) and a DPCM selection signal (f) synchronously with a synchronous signal (b) to a picture voice signal demultiplex circuit 3 and a DPCM/PCM conversion circuit 4 respectively. Then the picture voice signal demultiplex circuit 3 demultiplexes an input signal (a) into an audio signal (d) and a DPCM picture signal (e) and outputs them and the DPCM/PCM conversion circuit 4 converts the DPCM picture signal (e) into the PCM picture signal (g) and outputs the converted signal to a D/A conversion circuit 5. Thus, the voice signal is multiplexed even onto the vertical synchronizing part other than the synchronous base part and the resulting signal is transmitted.</p> |
