SYNCHRONIZING CIRCUIT OF OPTICAL HIGHWAY FRAME

摘要

PURPOSE:To know easily the position of a frame, by giving the different optical intensity to a frame pulse provided in addition to data from the optical intensity of other information and then discriminating the optical intensity of the frame pulse. CONSTITUTION:When a signal is fed to an input terminal 1, the signal is transmitted to an optical delaying element 3 with tap and an optical intensity detecting circuit 4 through an optical distributor 2. The circuit 4 performs a photoelectric conversion to extract only the frame pulse having high optical intensity. This frame pulse is then transmitted to a phase comparator 5 in the form of an electric signal. The circuit 5 performs a phase comparison between the frame pulse sent from the circuit 4 and a basic frame pulse 6. Then the tap is selectively controlled for a tap selecting circuit 8 so that an output signal having the coincidence of phase between an optical signal delayed by the element 3 and the pulse 6 is delivered to an output terminal 7.