| 摘要 |
PURPOSE:To obtain the frequency characteristic detector for transmission lines, having conventionality, by detecting the detection voltage corresponding to the slope of a horizontal synchronizing signal included in a video signal after detection and improving the electric characteristics of transmission system based on it. CONSTITUTION:The reproduced video signal from an input terminal 1 is fed to a pedestal clamp circuit 3 via a variable LPF circuit and this output is fed to a window comparator 4. To this comparator 4, the divided voltage picked up among a plurality of voltage dividing resistors 7-9 connected between standard power supply terminals 5 and 6 is applied, to form the pulse signal corresponding to the slope of the output from the clamp circuit 3. Next, this signal is fed to a switch circuit 12 via a monostable mutivibrator 10, AND gate 11, and integration is made at the integration circuit 14 and 15, and the difference is detected at a difference detection circuit 16. After that, this difference level is fed to a switch circuit 17 and it is fed back to a circuit 2 via an adder 18 connected to a DC power supply 19 and this output is synchronized with the signal from an input terminal 13. |
