| 摘要 |
PURPOSE:To simplify the constitution of an automatic tracking device of a magnetic-sheet reproducer by arranging two heads each having radius directional width which is wider than the track width in separating by the distance in the radius direction depending on the interval between neighboring two tracks, and by adjusting the relative position depending on the output difference of both heads. CONSTITUTION:When both heads 8 and 10 exist at the prescribed positions which are shown by a solid line at the time of completing tracking, both heads 8 and 10 can detect and reproduce video signals from respective all track widths (t), therefore, reproducing envelope outputs of both heads 8 and 10 go to equal each other. When tracking is not completed as shown by a one-point chain line, the head 10 cannot detect signals near the peripheral end of a track 2a although the head 8 detects and reproduces video signals from all track width (t). Therefore, the output of the head 8 goes to larger than that of the head 10. In such a way, tracking is executed automatically in accordance with the output difference of two heads 8 and 10 which are arranged in the radius direction. |
