MAGNETIC VIDEO RECORDING AND REPRODUCING DEVICE

摘要

PURPOSE:To obtain a normal sample pulse regardless of the lack of a main pilot signal, by forming a sample pulse from an output signal of a 1/2 frequency dividing circuit having its output state decided by the reproduced main pilot signal. CONSTITUTION:A signal (c) fed through a terminal 31 is a signal phase-locked with a horizontal synchronizing signal obtained during reproduction and is supplied to the clock input terminal of a JK flip-flop (JK-FF) 22. Further, a head switching signal (a) is supplied through a terminal 32, and a monostable circuit 30 is triggered by the fall. Then a pulse (b) is applied to AND circuits 23 and 24. The outputs of the circuits 23 and 24 are set at (0) while the pulse (b) is applied. Therefore the JK-FF 22 is not set nor reset, and the output of the JK-FF 22 is inverted by the input clock pulse. Then the JK-FF 22 is set when a main pilot signal (d) obtained in a reproduction mode is applied through a terminal 33. Thus an output Q is always set at (1) and then delivered through monostable multivibrators 26-29.