| 摘要 |
<p>PURPOSE: To simply detect a state of the end of a tape(EOT) in its approaching by measuring dynamic characteristics of two reels of a supply reel and a take-up reel and detecting them when a 2nd value reaches prescribed relation to a 1st value. CONSTITUTION: The tape 20 is taken up from the supply reel 12 to the take-up reel 14 at a constant linear velocity (v) by a tape storage device (driving device) 10, and the supply reel 12 and the take-up reel 14 possess optical sensors 22 and 24 respectively, so that an angular velocity of each reel is measured. Then, after obtaining an initial angular velocity WT( INIT) of the take-up reel 14, a ratio of this velocity to a tape velocity WT( INIT) /v is calculated and stored. During supply of the tape, a ratio of an angular velocity ws of the supply reel 12 to the tape velocity; wS/v is monitored, and is compared with the stored wT( INIT) /v, and the instant this comparison becomes wS/v>=WT( INIT) /v, an EOT signal is generated. By this method, the approaching EOT state can simply and effectively be detected.</p> |
