| 摘要 |
<p>PURPOSE:To surely draw out the subsequent synchronizing Signal even if the synchronizing signal has dropped out owing to the fault in transmission line by widening the pulse width of window pulses when a data error is detected. CONSTITUTION:When synchronizing detection output Pt and pulse width calibration output Pw are supplied to AND 64, the output thereof is supplied as a window pulse together with a reproduction horizontal synchronizing signal PHD to AND 47. When the output of the AND 47 is supplied to a monostable multi 48, the synchronizing pulse Pr in which the rise and fall of the signal PHD coincide apperas in its output termianl 49. By the rise of this pulse Pr, a counter, etc. constituting the pulse generating circuit on the write side are reset and the pulse being generated becomes the one synchronized with the reproduction PCM signal, then the data are correctly drawn out in a data draw-out circuit and time axis expanding processing is also correctly accomplished. Thereby, the subsequent synchronizing signal may be correctly drawn out even if the synchronizing signal has dropped out owing to the fault in the transmission line.</p> |
