| 摘要 |
PURPOSE:To display multiplex information to a prescribed position on a screen at all times by changing a reset operation of a vertical positioning counter in response to a vertical oscillating frequency in a multiplex signal generator deciding the horizontal and vertical display position. CONSTITUTION:When a vertical oscillation deflecting circuit 14 conducts the oscillation deflecting operation in a normal vertical oscillating frequency 60Hz at normal operation, a vertical sawtooth wave is extracted from an emitter of a transistor (TR) Q1 of a vertical deflection section 14a, and after the wave is shaped via a time constant circuit comprising resistors R1-R7 of a vertical blanking pulse generating section 14b and a capacitor, the result is applied to a base of a TRQ3. In this case, the TRQ3 is turned on only at the peak pulse period of the sawtooth wave top, a negative pulse is outputted from the collector of the Q3 and fed to a video output circuit 10 and then fed to the vertical positioning counter 17 as a reset pulse, and the count content of the counter 17 is reset at the rising of the pulse. |
