| 摘要 |
<p>PURPOSE:To grasp a current track without reproducing all the track addresses and to increase a track retrieving speed by switching to track density retrieval in the neighborhood of a target track address and scanning all the tracks. CONSTITUTION:An address detecting circuit 22 always detects a currently tracing track address, and an address comparing circuit 23 calculates the address difference between the current track address and the target track address. Further, when the address difference is large, an magnetic tape winding angle for a head drum 2 is made into 90 deg., and tape feeding speed is made into a high speed. When the circuit 23 detects the decrease of the address difference, the tape winding angle for the drum 2 is made into >=180 deg., and the tape speed is made into a low speed. According to the above-mentioned setting, all the tracks can be surely scanned, and the current track can be grasped without reproducing all the track addresses. Thus, the high-speed retrieval can be attained.</p> |
