| 摘要 |
<p>PURPOSE:To attain the automatic changeover of a mode in response to a tape during reproduction by inhibiting a reproduction control pulse input to a frequency division circuit for a prescribed period from the detection of pulse missing so as to prevent mis-discrimination at the generation of missing pulse. CONSTITUTION:A missing detection circuit 10 detects the missing of a control pulse inputted to a 1/2 frequency division circuit and the input of a reproduction control pulse to the frequency division circuit is inhibited for a prescribed period from the detection. Thus, the count of a counter 6 to the 1st and 2nd tapes just after the prescribed period is respectively larger and smaller than the reference value set to a comparator circuit 7 and the comparison signal inputted to a latch circuit is unchanged from the state before missiong. Even when the missing of the reproduced control pulse due to flaw of the tape takes place, whether the tape during reproduction is the 1st or the 2nd tape is discriminated without causing mis-discrimination so as to switch automatically the reproduction mode depending on the tape during reproduction.</p> |
