Dual mini-disk drive

Abstract

A disk drive comprising a first rotatable spindle for rotating removable flexible disks having magnetic surfaces for recording and retrieval of information and a motor for driving the spindle has an increased storage capacity by the addition of a second spindle driven by the motor in a direction opposite to the first spindle. The information storage capacity of the drive is further improved by increasing the track density of the disks while minimizing track seeking error of the magnetic read/write head associated with the disk. A stepper motor and lead screw are coupled to the magnetic read/write heads for radially positioning the heads to selected tracks of the received disks. The lead screw has a V-groove comprised of an alternating ramps and transition zones. As the lead screw rotates, a head carriage assembly having attached the first and second magnetic read/write heads is positioned radially by the transition zones while the ramps function to compensate for angular error of the stepper motor. By reducing angular error of the stepper motor, a concomitant increase in track seeking speed is achieved by permitting the stepper motor to operate at a greater angular velocity than would be obtainable without the lead screw of the invention. A further increase in track seeking speed is achieved by maintaining a headload pressure pad in close proximity to the surface of the disk opposite the surface to which the associated magnetic read/write head is closely positioned. Thus, upon command to contact the head with the magnetic surface of the disk, a reduced delay is achieved thus, improving track seeking speed.

Dependencies are inferred from the claim text.