| 摘要 |
PURPOSE:To always move a head at correct speed, by measuring an error in a speed detector, etc., with a rotary disk shaped storage device itself, and correcting a targeted speed signal. CONSTITUTION:The interval of a pulse that is the output of a track cross detector 5 is time-counted by a timer means 12, and the speed of a head 3 is counted from the number of recording tracks crossed by the head 3, and a time required for that, while a targeted speed is kept at a regulated value level. And the targeted speed is corrected on the basis of a calculated result. Thus, since the rotary disk shaped storage device itself corrects the speed detection error of the head 3 in a field, an adjustment at a manufacturing time is made unnecessary, and also, change due to change in the lapse of time of a circuit element, or peripheral circumstance can be absorbed. |
