| 摘要 |
PURPOSE:To execute a tracking control exactly, by moving up and down a rotary head by one frame unit in the track width direction, comparing plural sampling data of a reproducing signal in case of a state shifted in each direction, and detecting a track shift. CONSTITUTION:An FM video signal 3 is supplied to a sampling circuit 6 through an envelope detecting circuit 5. The sampling circuit 6 samples a video signal level of N parts of one recording track and provides it to a memory 9 by a sampling pulse from a pulse generator 7 by a drum pulse 4. On the other hand, the pulse generator 72 sends a head rocking signal of 2 field period to a head moving mechanism 15 through an adding circuit 13 and a head moving driving amplifier 14, and rocks the head in the width direction. Storage values of sampling data of the upper and lower displacement positions are compared by a voltage comparator 10, and its track shift detecting signal is sent to a tracking control voltage generating circuit 12 through a memory 11. In this way, the tracking control is executed exactly. |
