RECORDING AND REPRODUCING DEVICE

摘要

PURPOSE:To reproduce signals stably from the beginning of the reproduction signal by detecting an unrecorded section to insert a signal having an optional frequency there and performing the envelope wave detection with said inserted signal to produce a clipping signal for detection of the peak value of a differential signal. CONSTITUTION:The reproduction signal 51 given from a disk 1 is supplied to comparators 10-12 via an equalizer circuit 6, an LPF 7, the differential signal 8 and an amplifier 9. An unrecorded part detecting circuit 30 consists of an envelope wave detecting circuit, an amplifier and a comparator and actuates and oscillation circuit 31 only at an unrecorded part by the output signal 61 to produce an optional frequency. The output signal 62 of a switch circuit 33 is supplied to envelope wave detecting circuits 13 and 14, and the envelope signal is supplied to the comparators 11 and 12 in the form of the clipping signal to be compared with the differential signal 52. Thus the peak value of the signal 52 is detected. The envelope signal of an unrecorded section is used for the signal given from the circuit 31. Thus the detection is possible at and after the first peak value of the signal 52.