Arrangement for automatic track searching for oblique track recordings

Abstract

Apparatus is provided for automatic video track searching during the reproduction of still pictures from oblique magnetic video track recordings on a magnetic tape. The apparatus is adapted for use in a system including a rotating magnetic-head drum capable of generating position pulses. The apparatus provides for arbitrarily switching the tape-transport motor down to a slow speed and for a braking circuit to stop the tape-transport motor. A detecting circuit is provided to form a voltage envelope curve from signals generated by the video head or video heads, and a phase shifter for the position pulses compensates for phase errors in the machinery and circuitry. The apparatus also provides for the aforesaid switching upon a temporal coincidence between minima of a aforesaid envelope curve and the phase compensated position pulses. A sample and hold circuit scans the aforesaid envelope curve at times controlled by the phase compensated position pulses. The scanned signal is integrated and differentiated and, through a pulse shaper, operates upon the aforesaid switching means to bring the slow tape-transport motor motion to a complete stop.

Dependencies are inferred from the claim text.