| 摘要 |
PURPOSE:To attain automatic tracking by selecting a head element in the best tracking state by using a compound magnetic head consisting of at least three magnetic head elements. CONSTITUTION:Playback head 3 consists of three magnetic head elements HA, HB and HC. In playback mode, center head HB is initially positioned nearly in the center of recording track Tn at point P0 right after the starts of a scan on each track. A reproduced signal from HB is compared to those from HA and HC to select a head that reproduces a signal on track Tn also in the best state. For example, signals that heads HB and HC reproduce from track Tn are inverted in level in the middle between points P2 and P3. In this case, head HB is substituted by HC between P2 and P3. Even if, the track is curved, a signal free of beat interference with an adjacent track can be reproduced. |
