| 摘要 |
<p>PURPOSE:To lower a control frequency band and to realize the controllability similar to the case of a normal mode by lowering the gain of a tracking error signal to that of a long time mode by a gain changeover means. CONSTITUTION:The tracking error signal generated from a sample-and-hold circuit S/H 5 as a tracking error signal generating means is inputted by a gain changeover circuit 6 to output one time as much as a gain of the tracking error signal under the normal mode or to output 1/2 time of the tracking error signal under the long time mode. At the time of the normal mode or the long time mode, a changeover signal is inputted to the gain changeover circuit 6 by interlocking with a head changeover signal under each mode concerned out of the normal mode and the long time mode respectively. By this method, even under the long time mode, the controllability of a capstan is not deteriorated, but the good controllability can thus be obtained.</p> |
