Abstract: A storage device includes a substrate, a magnetic storage medium provided on the substrate, information being magnetically stored in the magnetic storage medium, a head unit, and a reciprocating mechanism provided on the substrate, the reciprocating mechanism causing the head unit to reciprocate in a plane parallel to a surface of the magnetic storage medium, wherein, while the head unit is being moved by the reciprocating mechanism, information is recorded in or reproduced from the magnetic storage medium via the head unit.

Abstract: A head actuator in a magnetic disk drive, including an actuator arm rotatably mounted on a base of the magnetic disk drive, a first driving mechanism for rotating the actuator arm, and a load beam for supporting at a front end portion thereof a slider carrying a head. The head actuator further includes a second driving mechanism composed of a leaf spring for elastically connecting a front end portion of the actuator arm and a base end portion of the load beam, and an electromagnetic motor for swinging the load beam with respect to the actuator arm.

Abstract: A magneto-resistive (MR) head has an MR layer in a space formed by shield layers by providing a distance enough to protect magnetic flux, flowing through the MR layer from a recording medium through a gap formed by the shield layers, from leaking out to the shield layers. A flux guide is provided between the MR layer and the gap, and has an end magnetically connected to the MR, extending over an effective area of the MR head, and another end having a width a little narrower than a width of track of the recording medium. A side of the MR layer, opposite to the side connected with the flux guide layer is placed in a narrow space formed at a corner of the space. Magnetic flux leaked from the gap due to a sense current flowing through the MR layer is eliminated by making a current flow through a recording coil layer or through an electrically conductive layer placed in the space.

Abstract: A magnetoresistive head comprises a magnetoresistive layer having an axis of easy magnetization in the direction parallel to an air bearing surface, a first electrode formed on the magnetoresistive layer on the air bearing surface side and an oblique side portion with respect to the air bearing surface, and a second electrode formed to be separated at a distance from the first electrode and having a side portion substantially parallel to the oblique side portion of the first electrode on the magnetoresistive layer.

Abstract: In a device which is adapted to write and read an information on and from a recording disk through a head and includes a head actuator for moving the head in a radial direction of the recording disk so as to position the head at a desired recording track on the recording disk, a mechanism for minute movement of a head provided at a part of the head actuator is capable of moving the head a very small distance independently of an operation of the head actuator. This mechanism for minute movement of a head is provided with expansion regions which are arranged symmetrically with respect to a center line of the head actuator and are separated by a clearance. Expansion members which are fixed on both or either of front and rear surfaces of the expansion regions, cause the expansion regions to expand or contract by the deformation thereof produced according to application of the power.

Abstract: An air-bearing head slider supports an electromagnetic transducer opposed to a rotating recording medium or magnetic disk. The slider includes a slider body having a bottom surface opposed to the rotating magnetic disk, the bottom surface having an air-entry end and an air-delivery end with respect to an air flow generated between the slider body and the rotating recording medium. A central rail is provided on the surface of the slider body at the air-entry end. The central rail extends from the air-entry end and terminates on its way to the air-delivery end. Two side rails are provided on the surface of the slider body at the air-delivery side and extend from the air-delivery end and terminate on their way to the air-entry end.

Abstract: A magnetic memory device comprises: a vertically magnetic recording medium; a probe formed of an electrically conductive as well as soft-magnetic material, a pointed end of the probe faces the magnetically recording medium across a gap; a magnetic flux detecting element for detecting a magnetic flux caught by the probe, where the magnetic flux is from a data recorded on the magnetically recording medium; a vertical controller for keeping the gap constant by the use of a tunnel current flowing via said gap into the probe while a voltage is applied across the gap; and a scan mechanism for scanning the probe along the magnetically recording medium. The magnetic memory device may further comprises an exciting coil for magnetizing the probe so as to write a data in the magnetically recording medium. The probe may be recessed from the scanning position when the probe is not in operation.

Abstract: A retracting assembly produces a constant torque, in a data zone of a magnetic disk, which is greater than static friction of a bearing for a rotary actuator. However, in a parking zone on an outer portion of the magnetic disk, the retracting assembly generates a torque which suddenly increases so that a large holding torque is obtained and a magnetic head is reliably locked.

Abstract: A magneto-resistive (MR) head has an MR layer in a space formed by shield layers by providing a distance enough to protect magnetic flux, flowing through the MR layer from a recording medium through a gap formed by the shield layers, from leaking out to the shield layers. A flux guide is provided between the MR layer and the gap and has an end magnetically connected to the MR extending over an effective area of the MR head, and another end having a width a little narrower than a width of track of the recording medium. A side of the MR layer, opposite to the side connected with the flux guide layer is placed in a narrow space formed at a corner of the space. Magnetic flux leaked from the gap due to a sense current flowing through the MR layer is eliminated by making a current flow through a recording coil layer or through an electrically conductive layer placed in the space.

Abstract: A spindle motor includes a permanent magnet multipolarized in a circular direction of the permanent magnet. The permanent magnet generates magnetic fluxes in a radial direction of the spindle motor. A core assembly has core pieces, the core pieces respectively including first portions are circularly arranged and face the permanent magnet via a gap, and second portions guide magnetic fluxes in parallel with a rotation axis of the spindle motor. Windings are turned around the second portions of the core assembly and have axes of the windings extending in parallel with the rotation axis of the spindle motor. A yoke magnetically couples the core pieces with each other.

Abstract: A maximum-likelihood decoding method for decoding an input signal subject to intersymbol interference. An assumption is made of a measure of an interference caused by a future signal that is later in a sequence than an assumed data sequence, on the basis of a predetermined bits of sample values of said input signal that are earlier in a sequence than an assumed data sequence stored in an assumed path memory (104). An assumed sample value of said input signal by referring to this measure of interference. Maximum-likelihood decoding is conducted on said input signal, on the basis of this assumed sample value and a sample value of said input signal; a plurality of survivor paths are generated and stored in a path memory (102); data for the most likely one of survivor paths is output as a decoded data sequence.

Abstract: A storage device includes a substrate, a magnetic storage medium provided on the substrate, information being magnetically stored in the magnetic storage medium, a head unit, and a reciprocating mechanism provided on the substrate, the reciprocating mechanism causing the head unit to reciprocate in a plane parallel to a surface of the magnetic storage medium, wherein, while the head unit is being moved by the reciprocating mechanism, information is recorded in or reproduced from the magnetic storage medium via the head unit. The reciprocating motion of the head unit is provided by piezoelectric elements on arms supporting the head, which move the head with a predetermined stroke width in simple harmonic motion.

Abstract: A magnetic disk storage apparatus comprising a rotary actuator which prevents head positioning error resulting from vibration and impact. Since head positioning error is generated when the enclosure makes rotating movement due to translational vibration input due to vibration, a vibration proof mechanism consisting of a plurality of vibration proof supporting members are provided between the enclosure and frame. The plural vibration proof supporting members are disposed so that the linear moment around the gravity center of the enclosure is balanced against translational external force applied to the enclosure.

Abstract: A Viterbi decoding system includes a characteristic estimator for estimating a characteristic of a system, and an equalizer for receiving an input signal from the system and for equalizing a waveform of the input signal so that an equalized waveform of the input signal is varied based on the characteristic of the system estimated by the characteristic estimator. A Viterbi decoder generates an output signal showing a maximum-likelihood path by using the equalized waveform of the input signal from the equalizer.

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.

Abstract: A rotating support apparatus in a disk storage device is provided with a stationary shaft, ball bearings rotatably fitted on the stationary shaft, a rotatable member rotatably supported by and on the ball bearings, and buffer rings superimposed between the associated ball bearings and the rotatable member to absorb a thermal deformation of the rotatable member due to a change in a temperature. The buffer rings have a same coefficient of linear expansion as that of the material of which the rotatable member is made, and each of the buffer rings is in contact, at two points of the outer inner surfaces thereof, with the rotatable member or outer races of the ball bearings, and at one point of the inner or outer surface thereof, with the associated ball bearing or the inner surface of the hub, respectively.

Abstract: A head suspension mechanism of a recording apparatus for flexibly carrying a transducer in a floating state. The mechanism comprises a head slider, a load beam, a spring plate, and an adjusting screw. The load beam is composed of a rigid section, a resilient section, and a holding section. The head slider is suspended at the free end of the rigid section through a gimbal. The load beam is secured to a supporting arm of the head actuator of the apparatus at the holding section, and loaded by the spring plate at the resilient section. The load is easily and precisely adjustable using the adjusting screw. Thus, the head slider contacts the disk at rest with a predetermined static load in order to maintain a favorable flying height of the head slider over the rotating disk. With the above configuration, the load provided by the spring plate is substantially increased as compared with the load to be applied to the head slider, enabling the easy and precise adjusting of the loading force.

Abstract: A magnetic disk storage apparatus in which a plurality of magnetic head positioners are independently driven with respect to each other. A housing having a sensor secured thereto indirectly senses mechanical vibration of a magnetic disk and issues a sense signal. The mechanical vibration is inevitably caused by a seek operation of a selected magnetic head positioner. Based on the sense signal, a compensating signal is generated in a mechanical vibration follow-up system disposed in the apparatus. The compensating signal is input to a coil of a driving motor of non-selected magnetic head positioners such that the effect of the mechanical vibration on the other positioners is cancelled. Thus, magnetic heads supported by the other positioners do not become off-track.

Abstract: A servo system, for positioning a transducer of a rotatable storage apparatus over a servo tracks of a magnetic disc processes trains of positioning pulse signals. A reference voltage, changing with time, having a predetermined pattern, is generated and compared with a train of positioning pulse signals. The magnitude of the positioning signals, which varies with the displacement of the transducer from a guide path to be followed, the number of the positioning signals exceeding the reference voltage pattern is counted and an error signal for the servo system is determined as a function of the count and is fed back in a digital form.

Abstract: A magnetic disk unit wherein a plurality of magnetic recording disks are mounted at predetermined intervals on a rotatably supported spindle via a magnetic recording disk mounting member having air ventilating holes which extend from the upper and lower portions thereof near the spindle to the spaces between the magnetic disks, air being circulated by the centrifugal force generated by rotation of the magnetic recording disks.