| 摘要 |
<p>PURPOSE: To detect an end part of a magnetic tape in a simple method by specifying a remaining time of the magnetic tape from revolution numbers of a feed reel and a wind reel and a run time of the tape. CONSTITUTION: Reel pulse signals indicating rotation cycles of a feed reel 12 and a wind reel 14 are generated from relay rotation detectors 22 and 24 set below the reels 12 and 14, respectively. The reel pulse signals are sent to a remaining time detector 30. An FG pulse signal corresponding to a rotation speed of a motor of a capstan unit 20 is generated at a frequency generator 18 and fed to the remaining time detector 30. The detector 30 operates and specifies a remaining time of a magnetic tape 10 from the rotation cycles of the reels 12, 14, a run time of the magnetic tape selected by a memory unit 26 and a count of FG pulses. Then, a tape end position detector 50 compares the detected remaining time with a preliminarily set threshold value of an end part, thereby detecting the end part of the tape.</p> |
