Method and circuit arrangements for detecting and evaluating faults in recording media having digital signals recorded on one or more tracks

摘要

A method and circuit arrangements for detecting and evaluating dropouts or drop-ins on recording media, comprising reading and modifying the recorded digital signals, the size and type of fault being evaluated on the basis of fixed threshold levels. In the case of a dropout, for example, the fault is weighted by determining the differential of the envelope of the read signal. In the case of a drop-in, other noise signals are left out of consideration by nonlinear emphasis of the drop-in and appropriate choice of the threshold value. A circuit combination enables both dropouts and drop-ins to be detected and evaluated.