| 摘要 |
PURPOSE:To detect and correct track jump only when unrequired track jump is generated by preventing the detection of vertical synchronizing signal interval change due to a cause other than the track jump. CONSTITUTION:An up/down counter to which a vertical synchronizing signal VS from a track jump correcting circuit 14 is supplied counts up clocks from a reference clock correcting circuit 42. The counted value corresponding to the change of the vertical synchronizing signal intervals is supplied to a decision circuit 33 to which a rotary head switching signal HSW is applied, and at the update of a track, the existence of track jump is discriminated and the position of the rotary magnetic head is controlled. On the other hand, the circuit 42 to which magnetic tape moving speed information 49 and a track updating signal from an inclined signal generating circuit 13 are supplied controls clock supply or the like to the counter, and at the time other than the generation of unrequired track jump, inhibits the counter 32 from executing counting corresponding to the vertical synchronizing interval change. Therefore, only the unrequired track jump is detected and the erroneous correction of a track jump is prevented. |
