| 摘要 |
PURPOSE:To reproduce even a special color system signal by providing a circuit which inverts the output of a vertical frame frequency discrimination circuit, and impressing a discrimination output to each demodulating circuit through the inverting circuit when this special color system signal is processed. CONSTITUTION:When a normal signal is received, a changeover switch 21 is connected to a contact (a) and when the color signal of a device for special reproduction is received, the switch is connected to a contact (b). When a PAL type signal is reproduced by an NTSC type device in said state, a vertical frame frequency discrimination circuit 14 outputs a high-level discrimination signal, but its polarity is inverted by the inverting circuit 22 and an NTSC type demodulating circuit 16 operates. On the other hand, when an NTSC type signal is reproduced by a PAL or SECAM type device, the discrimination signal is inverted by the inverting circuit 22 into a high-level signal of 50Hz in vertical frame signal and a demodulating circuit 17 or 18 operates. |
