| 摘要 |
<p>PURPOSE:To control tape driving with a short fast-forwarding and rewinding time by detecting only a rotation ratio of reels from a running system and detecting the approach of the end of tape winding to issue a tape running decelerating command. CONSTITUTION:A winding ratio calculating means 114 takes present take-up reel rotational frequency NT' and supply reel rotational frequency NS' of the outputs of a take-up reel rotational frequency detecting means 108 and a supply reel rotational frequency detecting means 109 as the input and outputs a present winding diameter ratio rT'/rS' (=NS'/NT'). An DELTArT delay means holds this output rT'/rS' of the winding diameter ratio calculating means 114 and delays it by DELTArT (=fixed) to output it. A subtracting circuit 116 subtracts a winding diameter ratio rT/rS of DELTArT before as the output of the DELTArT delay means 115 from the output rT'/rS' of the winding diameter ratio calculating means 114 and outputs a resultant value DELTA(rT/rS). A comparator 117 sends the decelerating command in the case of DELTA(rT/rS)>DELTA(rT/rS)0, and reels are decelerated and rotated because of approach of the end. Thus, the fast-forwarding and rewinding time is shortened.</p> |
