JPS576460A - Digital signal recording and reproducing device - Google Patents

Abstract

PURPOSE:To smoothly execute an acquisition of synchronization in case of controlling the running of a recording carrier by a pseudo servo-pulse from a frame synchronizing signal, by making this device execute the same operation as a regular phase synchronizing control in an asynchronous state of a control system. CONSTITUTION:A signal from a synchronizing signal detecting circuit 4 is inputted to a pseudo servo-pulse generating circuit 5, and it is provided to a PLL7 through a selecting circuit 16, and compared with a signal of a reference signal generating circuit 1, and it controls a relative speed of a reproducing head 3 and a recording carrier 2. In this case, a signal of the synchronizing signal detecting circuit 4 is inputted to a signal record detecting circuit 9 containing a counter 20, a flip-flop 19, a one-shot multivibrator 21, a gate circuit 8 is controlled, and also the selecting circuit 16 is controlled through a one-shot multivibrator 15. Accordingly, an acquisition of synchronization in case a control system enters a synchronizing state from an asynchronous state in the course of running of the recording carrier 2 is executed without delay, and the bit rate of a digital signal is kept exactly.