Automatic correction system for the servo-circuit in a device with optical scanning of a rotating information support

摘要

An automatic correction system for the servo-circuit of a device with optical scanning of a rotating information support, with a known servo-circuit (3) which announces anomalies in the scanning system (1) to whose outputs is connected a gate circuit, providing as necessary a mute control signal (MUTE) at the decoder (2) connected to the scanning system and thus ensuring the mute control of its outputs. According to the invention, anomalies in scanning can largely be reduced in terms of the disturbance caused by this phenomenon, by the fact that servo-specific indicator signals serve as a triggering criterion in the event of anomalies. This is achieved by the fact that on the basis of the current address data a recognition signal is formed in the comparison and correction system (6) by data monitoring (4) and by continuous storage (7); in this way, after the signalling of the termination of an anomaly a comparison is made between the old and new sub-code in order to form therefrom the appropriate correction signal, which is fed to the servo system (3) and which the scanning system (1) returns to the original scanning point.