| 摘要 |
PURPOSE:To provide a vertical amplitude switch circuit capable of full scan- displaying vertical amplitude even by a smaller signal of vertical video dual time. CONSTITUTION:A vertical frequency and a horizontal frequency when the vertical video dual time of an input signal inputted from input terminals l, 2 is reduced, are stored by a CPU 4, and when the signal with the same timing as the input signal of the vertical frequency and the horizontal frequency is inputted, a switch signal switching over the amplitude of a saw-tooth-wave inputted to the terminal F of a vertical output circuit 8 is outputted from the terminal E of the CPU 4. Based on the switch signal, a control circuit H turns on/off an FET 12, and controls parallel connection of a resistor 14 for the resistor 13, and switches over to the direction of increasing the amplitude of the saw-tooth-wave. |
