Abstract: On an FCP board and in a head amplifier circuit, provided for amplifying a read signal from a head and supplying the read signal to a read channel, a dummy wiring pattern is located near a wiring pattern for supplying the read signal. The head amplifier circuit incorporates a differential amplifier. The differential amplifier finds and amplifies a difference between the read signal supplied through the wiring pattern and the noise signal supplied through the dummy wiring pattern. The differential amplifier outputs to a read channel the read signal from which the noise has been removed.

Abstract: A disk storage system uses a disk on which servo data used for head positioning control is recorded as a storage medium. On the disk, servo burst data constructed by first to eighth burst patterns (A to H) having a recording width which is the same as a track width are recorded in a plurality of servo sectors provided in each track. The first and second burst patterns (A, B) are arranged in the opposite positions in the radial direction with the track center set as a reference (boundary position). The third and fourth burst patterns (C, D) are arranged in the opposite positions in the radial direction with the boundary between the adjacent tracks set as a reference. The fifth and sixth burst patterns (E, F) are arranged in the opposite positions in the radial direction with a preset position X1 in the range of the track set as a reference.

Abstract: In a computer system using either a memory card or a hard-disk drive (HDD) as an external storage device, a slot formed in a computer body for insertion of the external storage device is used commonly for the memory card and HDD. The HDD has an attachment guide member such that the HDD can be detachably mounted in the computer body through the slot. The HDD has a connector having the same specification standard as an interface connector of a memory card. The HDD is connected to the computer body via the connector for transmission of interface signals.

Abstract: A magnetic disk apparatus using a servo-surface servo and a data-surface servo is disclosed which comprises a servo disk which is disposed on a rotating axis and which has a servo surface on which first servo information is written and a data disk which is disposed on the rotating axis and which has a data surface. A servo head is provided for reading the first servo information from the servo disk and a read/write head is provided which works in association with the servo head for reading and writing information from and to the data surface. Structure is provided to generate a second servo information to be written on the data surface, to command a write timing of the second servo information, to control the write operation, and to control the positioning of the read/write head position. Thus, according to servo information being read from the servo head, servo information to be written to the data surface is generated and written to the data surface.

Abstract: In a composite servo system or a servo system using only a sector servo system, when a head switching mode is set during a read/write operation, a CPU checks whether the cylinder of a target track of a subsequent head after switching is the same as that of a target track of a preceding head. If the target tracks are located on the same cylinder, the CPU compares offset value data of a data surface corresponding to the head before switching with that of the head after switching. If an error, as a comparison result, falls within a predtermined allowable range, a read/write operation by the head after switching is continuously executed. The CPU generates correction data used for positional correction processing for positioning the head at the center of the target position of a hard disk and temporarily stores the correction data in a data memory. The CPU executes positional correction processing on the basis of the correction data stored in the data memory.

Abstract: In a servo type magnetic head drive control device, a moving velocity of a magnetic head is controlled on the basis of an error between an actual moving velocity value of the magnetic head generated using servo data and a target velocity value set in accordance with a moving distance to a target position. When the magnetic head is moved to a predetermined position, transient control is performing by using finite time settling control on the basis of position information and velocity information of the magnetic head, and normal tracking control or tracking control using the finite time settling control is performed to form positioning control of the magnetic head. Also a difference between the head position and the position of the head generated from a model is determined and used to control head movement.

Abstract: The invention comprises a voice coil motor for moving a head for reading information from or writing information to a disk, a driving circuit for supplying current to the voice coil motor in response to a first control signal and for changing the gain of the driving circuit in response to a second control signal. The gain of the driving circuit is increased during a moving control mode (i.e. a seek mode) and decreased during a position control mode (i.e. a track-following mode).

Abstract: A controlling apparatus for achieving velocity control in the course of a seeking operation of the magnetic head includes an intended address register for storing intended track addresses. A microprocessor calculates the intended moving distance of the head on the basis of an intended track address applied from the intended address register and track pulses applied from a track detector circuit every time the head crosses a track on the magnetic disk. On the other hand, previously stored in a memory are plural kinds of velocity tables consisting of plural kinds of intended velocity data which correspond to the intended moving distance of the head. The microprocessor reads and sets from the memory appropriate intended velocity data which corresponds to the intended and calculated moving distance of the head. The head is moved by a carriage and performs its seeking operation at an appropriate velocity on the basis of the intended velocity data set by the microprocessor.