Kabushiki Kaisha Toshiba

Yasuichi Hashimoto

Tomihisa Ogawa

A head actuator assembly of a disk device has a suspension which supports a head, an arm which supports the suspension and is rotatably supported by a bearing portion, signal wires which extend on the suspension and the arm and are connected electrically to the head, and a board unit. In manufacture, the signal wires are mounted on the suspension and the arm, and a connecting end portion of the board unit is connected to the signal wires mounted on the suspension and the arm. Thereafter, the head is mounted on the suspension and connected electrically to the signal wires.

Method of manufacturing a head actuator assembly and a disk drive

A disk drive including a magnetic disk having a plurality of concentric tracks formed thereon and a plurality of blocks each having data recorded on the track and a block address, a buffer memory, divided into plural segments, for storing data retrieved from the disk in each of the buffer memory segments, and buffer memory controller for controlling the buffer memory. The buffer memory controller includes a directory storage memory for storing buffer memory address information in directory segments corresponding to the buffer memory segments, a replacement control information storage memory for storing in each directory segment information relating to a history of use of data for each buffer memory segment. The buffer memory controller determines whether target data are stored in one of the buffer memory segments based on information relating to the target data and the information stored in the directory storage memory, and updates the information stored in the replacement control information storage memory according to a prescribed replacement control rule. The disk drive further includes a data process controller for controlling the buffer memory controller accessing the data in the buffer memory.

Hard disk drive having buffer memory employing directory based cache

A magnetic disk apparatus designed to obtain data on the position of heads and the rate of movement thereof by extracting the peak values of servo signals corresponding to the positions of a plurality of cylinders set to rotatable disks as analog data on the basis of predetermined timing signals and converting the peak values thus extracted into digital data.

Magnetic disk apparatus utilizing servo-surface servo

A write compensator for a magnetic disk apparatus includes a flip-flop for latching write compensation information using not a recording data format conversion reference clock but converted recording data. The flip-flop latches the write compensation information until the next recording data is input. The recording data is write-compensated on the basis of the latched write compensation information.

Write compensator for magnetic disk apparatus

A speed control apparatus includes a speed signal-holding circuit. Even if a discrete portion occurs in the position signal, i.e., if an abnormal signal component is included in the speed signal derived from position signal differentiation, the speed signal held by the holding circuit is output to prevent erroneous operation caused by the abnormal signal. In a magnetic disk apparatus incorporating the speed control apparatus, the magnetic head is driven before a seek instruction is completely input, and the position signal phases are switched at proper timings, thereby reliably performing both speed and positioning control operations of the magnetic head, at high speed.

Speed control apparatus in magnetic disk apparatus

A microprocessor is provided for calculating, based on the target track address set in the target address register, the target velocity in the seek operation of the magnetic head up to the target track. When the target velocity of the magnetic head is comparatively large, the microprocessor increases the revision interval of the target velocity, based on a prestored program, such that it is larger than the normal revision interval. The microprocessor varies the target velocity revision interval by a pulse signal output from a circuit which divides the track pulse by 1/2, for example.

Magnetic head control apparatus

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.

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Ome, Japan

Yasuichi Hashimoto