Abstract: A feedforward current from a feedforward current setting module, a target location trajectory from a position control module, and a correction value from a correction value setting module are produced for an elapsed time from each seek start time, namely at each sampling timing of a predetermined sample count. In the position control module, the position feedback control in response to an error between a target location and real position is performed in combination with the feedforward current. On a seek distance of one track, a coarse time is set to be 3 samples, for example. By intentionally slipping the target location trajectory from its ideal value, an overshoot and undershoot are restricted.

Abstract: A magnetic disk drive for locking an actuator mounted with a magnetic head in a safety zone. The magnetic disk drive comprises a magnet, fixed yoke members and a stopper for setting a stop position of rotations of the rotary actuator in such a position that torque by the fixed yoke members and the magnet is maximized. The fixed yoke members form a magnetic circuit for the magnet in all or a part of a movable range of the rotary actuator. The fixed yoke members include a first area having a gap width uniformly reduced in a lock direction to retract the rotary actuator and a second area having a gap width smaller than a gap width of the first area. The fixed yoke members are mechanically separated from each other.

Abstract: An existent filing apparatus transfers position information to a developing device. A microcontroller unit of the developing device calculates the current value for moving a head by using the position information in accordance with a firmware, and supplies the current value to the filing apparatus. The filing apparatus drives a motor on the basis of the current value, detects the current head position and supplies the detected head position to the developing device. The microcontroller unit of the developing device determines the next current value by using the head position information in accordance with the firmware, and a monitoring means of the developing device monitors the operation of the filing apparatus on the basis of the head position information and displays the monitored operation.

Abstract: The present invention proposes a system for positioning a control object such as a magnetic head by moving the object at a high velocity without generation of vibration. An actuator loads the magnetic head and an arithmetic control device controls a drive motor of the actuator based on a result of digital arithmetic determination. The arithmetic control device computes target position, target velocity and target acceleration of each sample period in accordance with polynomials indicating predetermined target position, target velocity and target acceleration. The arithmetic control device then outputs at least one error between a) the target position or target velocity as a result of determination and b) position or velocity of the magnetic head at every sample period and controls the drive motor with an added output of the position error or velocity error and target acceleration as a result of the determination.