| 摘要 |
PURPOSE:To receive a multiplexed information signal well without the dot interference with a normal screen, by amplifying a VIF signal in a wide band and by detecting this VIF signal by individual video detecting circuits for video display and multiplexed information display. CONSTITUTION:A VIF amplifying circuit 2 outputs a VIF signal having a wide band width up to a sound carrier frequency over a chrominance subcarrier frequency. This VIF signal is applied to the first video detecting circuit 3 and the second video detecting circuit 4 individually by two output difference lines provided in an output transformer. The detecting circuit 3 outputs a detection signal for video display having a frequency characteristic where the signal is attenuated by about 6dB in the chrominance subcarrier frequency. Meanwhile, the detecting circuit 4 outputs a detection signal for multiplexed information display having a flat frequency characteristic up to the about sound carrier frequency, and next, a video signal for multiplexed information display is outputted by a processing circuit 9. As the result, the multiplexed information signal is received well without the bad influence such as a dot interference upon a normal screen. |
