| 摘要 |
PURPOSE:To form an excellent pattern without distortion with simple constitu tion by shaping a peak of a parabolic waveform by a waveform shaping circuit and supplying the result to a base of a transistor (TR). CONSTITUTION:Supposing the forward voltage of diodes D1, D2 is VF and the Zener voltage of a Zener diode ZD1 is Vz, the diode D2 is conductive when V1>VF. Thus, an output shaped into a level decided by a voltage dividing ratio by a resistor R11 and a variable resistor R14 is obtained with respect to a signal voltage over+VF. When the signal voltage V1 exceeds the level being the sum of the voltage VF of the diode D2 and the Zener voltage Vz, since the diode ZD1 is conductive, te variable resistors R14, R13 are connected in parallel. Thus, an output shaped into a level decided by a voltage division ratio by the resistor R11 and the variable resistors R13, R14 is obtained with respect to the signal voltage being VF+Vz or over. Then the waveform-shaped parabolic signal voltage V2 is given to the base of a TR 62 to modulate the voltage form the+B2 thereby correcting the pattern distortion shown in dotted lines into a picture shown in solid lines. |
