Detecting anomalies in a scanning signal

摘要

An apparatus for scanning a track on a record carrier has a head ( 22 ) and front end circuitry ( 31 ) for scanning the track and generating scanning signals. A detection unit ( 32 ) detects anomalies in the scanning signal, for example for adjusting a tracking servo. The detection unit ( 32 ) calculates a mean value of the scanning signal and compares the mean value to a threshold for providing an anomaly detection signal ( 33 ). Further a classification unit ( 34 ) provides an indication of the type of defect for determining a suitable responsive or corrective action.