DETECTING CIRCUIT OF SERVO INFORMATION

摘要

PURPOSE:To ensure the effective use of a data and to increase the reliability of a device, by carrying out an information process after deciding whether the data track is effective or not in accordance with the degree of missing of the servo signal on a magnetic tape. CONSTITUTION:A flip-flop 1 turns on a waveform output of D to supply it to an AND gate 2 and delivers waveform A with a clock supplied independently. This output is supplied to a counter 3 to count the clocks, and an AND gate 4 supplies the output of a fall detecting circuit 5 of the output waveform and the clock to deliver waveform B. The gate 4 then supplies the value of the counter 3 to a register 6. The register 6 turns off the input given from the gate 4 with an operation of a rise detecting circuit 7 of the output waveform. The outputs of the counter 3 and the register 6 are supplied to a comparator 8 to decide whether the control information of the pulse input of 8 frequencies is effective or not based on the prescribed standard. This control information is supplied to an AND gate 9 along with the output waveform to decide a normal process or an abnormal process for the input information. Thus the decision information is delivered.