| 摘要 |
<p>PURPOSE:To make the tape speed constant independently of the size of tape by calculating the width of output pulse of both detectors when a tape is driven at a constant speed so as to convert the result into a tape length and using a tape speed proportional to the converted tape length as a setting voltage. CONSTITUTION:Detectors FG1, FG2 to detect the rotational speed of the tape supply reel 1 and take-up reel 2 are provided, and a tape speed voltage V1 is obtained from the square sum T1<2>+T2<2> calculated from two output data, rotational periods T1, T2 obtained from both the detectors FG1, FG2, the pulse width of the output of both the detectors FG1, FG2 is calculated when the tape is at a constant speed to convert the result into the length (l) of the tape. Then a tape speed setting voltage V2 proportional to the length (l) of the tape is obtained, both the tape speed voltages V1, V2 are compared and the voltage difference is fed to the drive motor. Thus, the tape speed is made constant independently of the tape size.</p> |
