| 摘要 |
<p>PURPOSE:To make it possible to output a 1st control signal according to the result of the discrimination of not less than two system signals among NTSC, PAL, SECAM and other-system signals, and also to output a 2nd control signal by detecting the state of a video recording and reproducing device. CONSTITUTION:To discriminate between NTSC and PAL systems, discriminator 1 of video recording and reproducing device 6 pays attention to a difference in the period among a horizontal synchronizing signal and counts the number of synchronizing signals within a certain time and, for example, when the result of the discrimination indicates the NTSC system, a signal of a high level is outputted to terminal 2 while that of a low level is outputted in case of other systems. The outputted signal of the high or low level is superposed upon a video signal supplied to video signal input terminal 4 by video signal processor 3 and the obtained signal is outputted to video signal output terminal 5. In receiver 19, the signal of the high or low level is detected and, for example, when it is high in level, the operation of the NTSC system is carried out to change color processing circuits over.</p> |
