| 摘要 |
<p>PURPOSE:To travel a magnetic tape at a required speed for any of plural traveling speeds of the magnetic tape corresponding to plural operation modes without depending on an alternation of an input voltage by controlling the position of an endless belt in its radial direction in corresponding to the r.p.m. of a pulley as previously determined based on a driving power level. CONSTITUTION:When the driving power level to be inputted to a motor controlling means 31 is varied, the ratio of the r.p.m. of a motor 25 to the r.p.m. of the pulley 23 is altered by controlling the endless belt 24 in its radius-directional position with a pulley control means 39 based on the variation of this driving power level. Consequently, even when the r.p.m. of the motor 25 is varied, variations of duty value can be diminished in the motor control means 31 against its inputted driving power, because the r.p.m. of the pulley 23 is kept approximately constant. By this method, the traveling control on the magnetic tape 21 can stably be performed, irrespective of the plural traveling speeds of the magnetic tape 21 corresponding to the individual operation modes and without depending on the specific alternation of the driving power level for regulating the r.p.m. of the motor 25.</p> |
