| 摘要 |
<p>PURPOSE:To automatically set an on-track position by setting the reference value of an on-track state at the optimum state automatically by a reference value generating means. CONSTITUTION:A time difference detection circuit 109 discriminates which horizontal synchronizing signal 107 or 108 is reproduced first. A circuit 114 is a maximum value detection circuit, and outputs a signal 115 whose polarity changes when a signal reproduced by a head 1011 becomes maximum. A reference value generation circuit 112 generates the reference value by using the value of a time differential signal 110 at a time when the polarity of the signal 115 changes. A track deviation arithmetic circuit 111 outputs a tracking error signal 116 which drives an electric-mechanical conversion element so as to minimize a difference between the time differential signal 110 supplied from the time difference detection circuit 109 and the reference value supplied from the reference value generation circuit 112, and controls the feed phase of a tape. In such a way, it is possible to prevent the deviation of tracking from being generated.</p> |
