| 摘要 |
<p>PURPOSE:To simplify the constitution of a driving device for controlling the tape speed at a constant speed by constituting a constant speed driving control for tape in application of two control systems and changing the control systems. CONSTITUTION:A rotary pulse signal of a rotary roller 13 provided on a tape traveling course is inputted to a roller period detector 14, and rotary period information TR for showing a rotary period of the rotary roller 13 is supplied to a subtractor 15. One input terminal of a comparator 29 is supplied with the rotary period information TR of the rotary roller 13, while the other input terminal with changeover reference information Chg corresponding to a tape speed for changing the 1st and 2nd control systems from a terminal 30, and a 1st switch 18 is changed in accordance with these two bits of information TR and Chg in size. Then, the revolving speed of a T-reel motor 32 is controlled in order to make the rotary period information TR of the rotary roller 13 constant when the tape speed is slow, and also in order to make information for a sum of squares of the rotary periods of both reels 2 and 5; TS<2>+TR<2> constant when the tape speed is fast. By this method, a constant speed tape moving control can be performed with a capstanless tape driving mechanism, thus simplifying the device.</p> |
