| 摘要 |
PURPOSE:To make the best adjustment even when a signal of different format is generated by squaring the output of a horizontal scanning frequency detecting means by a squaring means and constituting the slave line of a crosshatching signal with output pulses of a pulse width variable control multivibrator which controls the output pulse width of said detecting means almost in inverse proportion. CONSTITUTION:A vertical scanning frequency fV detector 5, a horizontal scanning frequency fH detector 4, a multiplier divider 6, a monostable multivibrator means 10 are combined, a signal which is proportional to f<2>H/fV is obtained by the multiplier divider 6, and the pulse width of the monostable multivibrator 10 is controlled almost in inverse proportion to the obtained signal to generate longitudinal lines of the crosshatching signal. Consequently, the crosshatching signal which has longitudinal line width nearly equal to one scanning line interval is generated at all times. |
