Helical scan tracking apparatus including means for correcting for track curvature

摘要

A scan tracking circuit for helical scan video tape recorders. The circuit creates and combines three control signals and generates as an output a deflection signal which serves to accurately maintain the scanning head on a desired track. The first control signal is sawtooth shaped and is based upon and derived from the speed of the tape. The second control signal is dependent on the signal which is developed by the scanning head and is also correlated with other signals which are obtained from previous scans of a previous scanned video track. The third signal is selected from a plurality of stored signals each of which is tailored to correct for a characteristic curvature pattern associated with video tracks produced by a particular VTR machine. The final deflection signal is a composite of the three control signals.