Method for automatic adjustment of the scanning track in magnetic video tape devices with helical track recording

摘要

In a method for the automatic adjustment of the scanning track for magnetic video tape devices with helical track recording with a replay speed which can be changed step by step by the recording speed, the two magnetic heads, which are arranged offset by 180 DEG on the head wheel, are preset in their position by means of piezoelectric crystal actuators in accordance with the theoretical scanning variation at the respective replay speed (skew input). To avoid the noise zones in the picture given during the transition from one nominal speed to the other, each magnetic head is spatially offset by the actuators in proportion to the function of the change in speed from one nominal speed to the other by a skew input and a relative track offset compared with the last scanned track by inputting a corresponding control voltage before the beginning of scanning.