| 摘要 |
PURPOSE:To keep the tape speed at a fixed level in a quick traversing mode by delivering a pulse having the width porportional to the number of revolutions of reels to control the voltage of a driving motor for supply reel when the number of revolutions of both supply and take-up reels are decreased less than the fixed value. CONSTITUTION:The revolving speed of a take-up reel is high at a time point close to the start of a quick traversing mode, and therefore the revolution detecting pulse obtained by a detector 8 has a short cycle. A modulator 10 is triggered again after triggering and delivers no pulse. While a modulator 11 delivers a pulse having the width proportional to the number of revolutions of the supply reel which is less than a fixed level. This pulse is sent to a selector 12 and integrated by an integrator 13. This integrated pulse is applied to a controller 14 as the correction control voltage of a supply reel driving motor 15. The correction control voltage is not generated in a middle period, and the correction control voltage is applied again to the motor 15 when the number of revolutions of the reel 6 is decreased less than the prescribed level. As a result, the tape speed of the quick traversing mode is kept at a fixed level. This improves the signal processing characteristics of the quick traversing mode. |
