| 摘要 |
<p>PURPOSE:To reduce the thickness and weight of a capstan motor and to improve the stability in a tape speed by detecting the tape speed in an optical manner. CONSTITUTION:A light emitting device 1 and a light receiving device 2 interposed inbetween a magnetic tape 3, and the light from the device 1 passes through the equidistantly spaced holes 4 of the tape 3 and is detected by the device 2 so that pulses of a frequency proportional to the tape speed are generated and compared at 9 with reference signals. The speed of a capstan motor 7 is controlled in accordance with the differential signals.</p> |
