| 摘要 |
PURPOSE:To run a magnetic recording medium constantly on the basis of only rotation information on a feed or/and a take-up reel by controlling the feed or/and takeup reels without providing a capstan, pinch roller, etc., which are in contact with the magnetic medium. CONSTITUTION:A microprocessor 5 performs calculation in accordance with a previously programmed expression by using digital values w1 and w2 from analog-ditial converting circuits 3 and 4 corresponding to the rotating angular velocities of the feed and take-up reels RS and RT, and the output of the microprocessor 5 is applied to a digital-analog converting circuit 6 to obtain an analog signal. This analog signal has a voltage corresponding to the running speed of the magnetic recording medium, so a comparing and amplifying circuit 11 performs error amplification regarding a reference voltage 10 corresponding to a specific velocity and sends its output to amplifying circuits 12 and 13 which operate differetially to control driving motors M1 and M2 for the feed and take- up reels RS and RT, running the magnetic recording medium at an invariably constant speed. |
