Abstract: A storage data reconstruction system including a plurality of storage units for storing therein divided data units for storing therein ECC data corresponding to the divided data; a spare storage unit for storing therein reconstructed data; an I/O-reconstruction control circuit; a timer; a data reconstructing table for a storage unit which has failed; and a circuit for reconstructing faulty data. When a failure occurs in any of the storage units, the failure is detected by an error check, a state of the failure is discriminated, a preferred processing suitable for the state of the failure is selected from a processing of a normal access or read/write, and a data reconstruction processing, and the selected processing is carried out, or the frequency of the processing of the normal access or read/write and the data reconstruction processing, or the ratio of the amount of the data reconstruction processing within a unit time, is set.

Abstract: In a disk array system for RAID (level 5) to improve a process performance by dispersing data, the overhead during data writing operation is reduced. Even when write data are used to rewrite data #1 to data #4, which have already been written at address SADR 2, SADR 2, SADR1 and SADR 3 within drives as data belonging to mutually different parity groups, these data are considered as new write data, and then these new write data are written in parallel into, for instance, an empty region in the drive at the address SADR 4. The updated old data or the updated old parity data are not read out. The invalidation flags for the updated old data are registered into an address conversion table. The subsequent data readout operation is carried out from a newly written region. When all of data within the original parity group are invalidated, the region holding this group is used as an empty region. The valid data within the parity group, which have been partially invalidated, are replaced at a proper timing.

Abstract: An array disk system includes a plurality of disk drives having disk-like recording media each having a surface divided into a plurality of zones and the data capacity per track is varied in each zone. The plurality of disk drives are divided into a plurality of groups. Reading/writing heads of the disk drives are positioned to access tracks having different zones on the disks in each zone on the basis of a cylinder address designated by a host system. Data transferred from the host system is divided in accordance with a ratio of data capacities of the tracks to be accessed and is recorded in each of the disk drives simultaneously.

Abstract: An array disk subsystem including a command selector for separating a signal from a host into a data item and a command, a data dividing unit for subdividing the data item, an ECC generator for producing an ECC for each of the obtained subdata items, a group of data disks for respectively storing thereon the subdata items and the ECCs, a command interpreting unit for interpreting the command, an I/O counter for counting I/O commands in the command, a backup processor for requesting a backup command based on count information of the I/O counter, and a backup unit responsive to the backup command for sequentially reading the subdata items and the ECCs from the data disks to record therein the subdata items and the ECCs.

Abstract: An error correction circuit which includes a specification circuit for specifying erroneous portions in a first data set reproduced from a recording medium, a register for storing the reproduced first data set including the erroneous portions thus specified and a reproducing circuit responsive to the reproduced first data set for reproducing again the first data set from the recording medium to obtain retry data, when there exist erroneous portions in the reproduced first data set stored in the register. The correction circuit also includes a data replace circuit, connected to receive the retry data, for replacing information at the specified erroneous portions in the reproduced first data set stored in the register by information at corresponding portions in the retry data.

Abstract: A magnetic recording/reproducing head assembly comprising a first magnetic path forming member on which a coil is mounted, a second magnetic path forming member which forms a magnetic path in cooperation with the first magnetic path forming member, and a film laminate formed at a front gap portion between the first magnetic path forming member and the second magnetic path forming member. The film laminate includes a magnetic detecting element for detecting a change in a magnetic field and a soft magnetic film or films. This magnetic head assembly is prepared by forming the film laminate on a head base of the head assembly, bonding a core member to the head base with the film laminate formed thereon, and mounting a coil on the core member.

Abstract: A parallel transfer type disk system comprising: a means for parallel dividing input digital data; a plurality of magnetic disks for recording each of said divided digital data, said magnetic disks including a plurality of magnetic heads for allocating said divided digital data to a plurality of tracks on a plurality of magnetic recording disks for simultaneous recording of the data, and a magnetic head driving means including a head selection means for driving said magnetic heads; a means for detecting defective track among said plurality of tracks from each of track signals; and a means for temporarily recording digital data allocated to a defective track and then recording the data on a predetermined track, or for simultaneously recording digital data allocated to said defective track and digital data allocated to tracks other than said defective track on a predetermined group of replacement tracks on said plurality of recording media, when existence of said defective track has been detected by said detect

Abstract: A readout circuit in magnetic recording device is disclosed, in which a test data signal for detecting an error in the characteristics of an automatic equalizer is recorded in a predetermined position of each track of a magnetic recording medium. In readout mode, a test data signal for a selected track is read out first, and this signal is compared with a reference signal dependent on the system conditions to determine an error from the reference signal. The optimum equalization coefficient is determined to eliminate this error from the reference signal and set in the equalizer. The data is readout under the optimum equalization characteristics thus set.

Abstract: A shunt biased magnetoresistive element includes a sensor part sensitive to an external magnetic field and a pair of leads (electrodes) in contact with the sensor part. The width (W) of the contact between the sensor part and each of the leads is selected to be equal to or larger than the width (L) of the sensor part. The MR element further includes a center tap having a width (W') selected to be two or more times as large as the width (L) of the sensor part, because the quantity of current flowing through the center tap is two times as large as that flowing through each of the end leads.

Abstract: Magneto-resistive head comprising a magneto-resistive film, and a soft magnetic film disposed at one side of said magneto-resistive film, which soft magnetic film is magnetized by electric current flowing through the magneto-resistive film, to which a bias magnetic field is applied by the magnetization of the soft magnetic film, whereby they are so structured that 0.7.times.B.sub.SMR .times.T.sub.MR <B.sub.SSF .times.T.sub.SF is satisfied, where T.sub.MR and B.sub.SMR represent the thickness and the saturated magnetic flux density, respectively, of the magneto-resistive film and T.sub.SF and B.sub.SSF represent the thickness and the saturated magnetic flux density, respectively, of the soft magnetic film.

Abstract: A soft-film-bias type magnetoresistive device is disclosed in which a high-permeability magnetic film, an insulating film and a permalloy film are formed on a substrate in this order, and first, second and third electrodes, which are parallel to each other, are provided on the permalloy film, to form a differential type magnetoresistive device. In this magnetoresistive device, a bias magnetic field which is generated and applied to the permalloy film between the first and second electrodes, is opposite in direction to a bias magnetic field which is generated and applied to the permalloy film between the second and third electrodes.

Abstract: In a plurality of magnetoresistive heads for reading information from regions obtained by dividing a disk-shaped recording medium into concentric circles, the thickness of a magnetoresistive film included in a magnetoresistive head assigned to an outer region is made larger than the thickness of a magnetoresistive film included in a magnetoresistive head assigned to an inner region.

Abstract: The present invention relates to the structure of a magneto-resistive head for reducing the spike noises generated in the head and for increasing the signal to noise ratio when the information is reproduced. In order to achieve the object, an electric conductor layer is disposed at both sides or one side of a magneto-resistive element, and the conductor layer is isolated from the element and connected to a DC potential.

Abstract: A circuit for detecting the variation of resistance of a variable-resistance element comprises a pair of grounded-base transistors with their base electrodes provided with different base voltages and with their emitter electrodes connected to both terminals of the variable-resistance element so that the voltage between both terminals of the element is kept constant. The current density of the variable-resistance element does not vary when the resistance of the variable-resistance element varies, whereby the lifetime of the element can be prolonged.

Abstract: Disclosed is a magnetic transducer using a magnetoresistance effect, comprising a magnetoresistive film, a hard magnetic film for applying a transverse biasing magnetic field thereto, and a conductive film through which current for applying the transverse biasing magnetic field to the magnetoresistive film flows. The conductive film may be either in electrical contact with or in electrical insulation from the magnetoresistive film. In this magnetic transducer, even when the heights of the respective constituents have changed, the transverse biasing magnetic field to be applied does not change considerably, and an optimum bias field strength is readily attained.

Abstract: In a current driving circuit which supplies a two-terminal load with current to be inverted in accordance with input information, a current driving circuit according to the present invention comprises a load whose one-side terminal has its potential fixed, circuitry to supply a non-fixed side terminal of the load with a direct current, and circuitry to supply the non-fixed side terminal with a current having a magnitude double that of the direct current and a polarity opposite to that of the direct current, while switching it in accordance with input information. Owing to such construction, the number of terminals to be led out from the loads can be reduced, and a load current can be inverted at high speed. In addition, reliability can be enhanced because the assembling process is simplified.

Abstract: The difference between the two gain control signals for two amplifiers which correspond to two of a plurality of read heads which have the maximum and minimum output levels is detected. Whether or not the difference exceeds a predetermined value indicates an abnormality of the outputs of the read heads due to dust adhering thereto.

Abstract: The present invention is to increase the carrier level so as to improve the S/N ratio when the factor T.sub.93, T.sub.T or T.sub.Q is small in level. When the level is low, noises are apt to be offensive to a listener's ear, but the reproducing level may be judged by the low level of T.sub..SIGMA., T.sub.T or T.sub.Q. Accordingly, the low level of T.sub..SIGMA. or T.sub.T is detected to raise the carrier level, and to reduce an FM demodulation noise and hence to improve the total S/N ratio.

Abstract: A multi-directional stereo multiple recording and reproducing apparatus is disclosed in which a plurality of sound source signals are encoded to a plurality of main- and sub-channel signals, the encoded main-channel signals and a carrier signal of a frequency f.sub.c which is angle-modulated with the sub-channel signals are mixed through a filter circuit, and the modulated signal is recorded on a lacquer master disc by a constant acceleration cutting and then reproduced therefrom.

Abstract: A device which reduces beat distortion caused by crosstalk between subchannel signals in a multichannel sound system. To effect reduced beat distortion, one component present in both the sum and difference subchannel is attenuated before the subchannels are modulated.