Head positioning system for floppy disk drives.

摘要

The head positioning system comprises an initial positioning controller (8) for prepositioning a magnetic head (3) within a predetermined distance from the center line of a target track in accordance with a position error signal (b) which indicates a deviation of the magnetic head (3) from the center line of the target track, a positioning compensation controller for generating a compensation signal whose frequency is equal to twice a disk rotational frequency, the positioning compensation controller positioning the magnetic head (3) at the center line of the target track by means of the compensation signal after the prepositioning operation of the initial positioning controller (8), and a switching compensation controller connected to the positioning compensation controller for enabling the compensation signal to be equal to the output of the initial positioning controller (8) during the prepositioning operation. This head positioning system positions the magnetic head at the center line of a target track at high speed and with a high accuracy even if the deviation of the magnetic head is larger than a track width when the closed loop servo is started to operate.