Abstract: A disk array system having first and second housings and a controller for controlling the first and second housings. Fiber channel hard disk drives are received in the first housing, and serial ATA hard disk drives are received in the second housing. When reading data stored in a serial ATA hard disk drive in the second housing, the controller reads a plurality of pieces of data including the data to be read and parity data for the plurality of pieces of data from all the hard disk drives of an RAID group to which the hard disk drive storing the data to be read belongs. Thus, the controller examines whether the plurality of pieces of data including the data to be read are written in the hard disk drives with erroneous contents or not.

Abstract: A disk array system having first and second housings and a controller for controlling the first and second housings. Fiber channel hard disk drives are received in the first housing, and serial ATA hard disk drives are received in the second housing. When reading data stored in a serial ATA hard disk drive in the second housing, the controller reads a plurality of pieces of data including the data to be read and parity data for the plurality of pieces of data from all the hard disk drives of an RAID group to which the hard disk drive storing the data to be read belongs. Thus, the controller examines whether the plurality of pieces of data including the data to be read are written in the hard disk drives with erroneous contents or not.

Abstract: A disk array system having first and second housings and a controller for controlling the first and second housings. Fiber channel hard disk drives are received in the first housing, and serial ATA hard disk drives are received in the second housing. When reading data stored in a serial ATA hard disk drive in the second housing, the controller reads a plurality of pieces of data including the data to be read and parity data for the plurality of pieces of data from all the hard disk drives of an RAID group to which the hard disk drive storing the data to be read belongs. Thus, the controller examines whether the plurality of pieces of data including the data to be read are written in the hard disk drives with erroneous contents or not.

Abstract: A disk array system having first and second housings and a controller for controlling the first and second housings. Fiber channel hard disk drives are received in the first housing, and serial ATA hard disk drives are received in the second housing. When reading data stored in a serial ATA hard disk drive in the second housing, the controller reads a plurality of pieces of data including the data to be read and parity data for the plurality of pieces of data from all the hard disk drives of an RAID group to which the hard disk drive storing the data to be read belongs. Thus, the controller examines whether the plurality of pieces of data including the data to be read are written in the hard disk drives with erroneous contents or not.

Abstract: An electronic apparatus includes an electronic device including electronic circuits, a first connector connected to the electronic circuit, and static electricity removal means, and a control device which includes a plurality of second connectors for connecting the electronic device and which is electrically connected to the static electricity removal means when the electronic device is being inserted and is electrically connected to the electronic device only via the first connector and the second connectors when the electronic device is mounted. Thus, it is possible to gradually discharge the static electricity when the electronic device is inserted into the control apparatus.

Abstract: A magnetic disk drive has a housing for a 3.5 inch form factor and disk media of a diameter for a 2.5 inch form factor. The smaller disk media rotate at a high speed while consuming low electric lower and generating less heat while providing for quick access speeds. Usually, when the magnetic disk media are rotated at a higher speed, the electric power consumption and heat generation are increased because of the load increase. This problem is avoided with the use of cooling fins placed about the periphery of the disk media. Further, the smaller size disk media enable a decrease in torque loss during on-load rotation with the media, and a decrease of electric current to the spindle motor during rotation.

Abstract: A magnetic disk drive that shape coefficient is 3.5 inches are provided, which is designed as rotating magnetic media in a high speed in order to consume a low electric power, to generate a less heat, and to access more quickly.

Abstract: A magnetic disk drive that shape coefficient is 3.5 inches are provided, which is designed as rotating magnetic media in a high speed in order to consume a low electric power, to generate a less heat, and to access more quickly.

Abstract: A magnetic disk drive that shape coefficient is 3.5 inches are provided, which is designed as rotating magnetic media in a high speed in order to consume a low electric power, to generate a less heat, and to access more quickly.

Abstract: In a magnetic recording drive having a plurality of magnetic heads each employing a magnetoresistive sensor for the purpose of averaging the time required for sense currents to be caused to flow through the respective magnetoresistive sensors to shorten the longest reproducing time and to suppress the degradation of the characteristics due to the electromigration, thereby improving the reliability of the magnetic recording drive, the magnetic recording drive includes circuits for averaging the useful life depending on the currents caused to flow through the respective magnetoresistive sensors among the plurality of magnetic heads, whereby the time required for the sense current to be caused to flow through one MR reproducing head is greatly shortened. Therefore, the levels of outputs of the MR reproducing heads can be increased without reduction of the reliability and thus the reliability of the magnetic recording drive can be improved.

Abstract: In a magnetic recording drive having a plurality of magnetic heads each employing a magnetoresistive sensor for the purpose of averaging the time required for sense currents to be caused to flow through the respective magnetoresistive sensors to shorten the longest reproducing time and to suppress the degradation of the characteristics due to the electromigration, thereby improving the reliability of the magnetic recording drive, the magnetic recording drive includes circuits for averaging the useful life depending on the currents caused to flow through the respective magnetoresistive sensors among the plurality of magnetic heads, whereby the time required for the sense current to be caused to flow through one MR reproducing head is greatly shortened. Therefore, the levels of outputs of the MR reproducing heads can be increased without reduction of the reliability and thus the reliability of the magnetic recording drive can be improved.

Abstract: An explosion-proof battery includes a cover unit fit into an open portion of a cylindrical cup-like casing. The cover unit is electrically connected to a lead tab extended from an electricity generating unit installed in the casing. The cover unit includes a metal terminal plate of relatively high rigidity, a pressure sensitive plate in the form of a metal plate having relatively high flexibility and vulnerability, a fixing plate of insulating material, an electrical conductive member including an upwardly projecting portion and a base portion, and a ring-shaped gasket of insulating material. The terminal plate and the fixing plate have respective vent holes. The electrical conductive member and the pressure sensitive plate are connected to each other at a connecting portion on the projecting portion of the conductive member by welding. A tip end portion of the lead tab is connected to the base portion of the conductive member.

Abstract: In a magnetic recording drive having a plurality of magnetic heads each employing a magnetoresistive sensor for the purpose of averaging the time required for sense currents to be caused to flow through the respective magnetoresistive sensors to shorten the longest reproducing time and to suppress the degradation of the characteristics due to the electromigration, thereby improving the reliability of the magnetic recording drive, the magnetic recording drive includes circuits for averaging the useful life depending on the currents caused to flow through the respective magnetoresistive sensors among the plurality of magnetic heads, whereby the time required for the sense current to be caused to flow through one MR reproducing head is greatly shortened. Therefore, the levels of outputs of the MR reproducing heads can be increased without reduction of the reliability and thus the reliability of the magnetic recording drive can be improved.

Abstract: A method of recording a servo signal on each track of a magnetic disk includes a first signal for demagnetizing the magnetic disk and a second signal for forming the servo signal. The recording width (core width) of the magnetic head is made greater than the width of the track. Parts for recording signals and not recording signals are set in each track. The first and second signals are selected and recorded in the signal recording part, thereby to form the servo signal. Current to be conducted to the magnetic head is cut in the part for not recording signals, and the track is skipped to the next part for recording signals. When the recording of the track has ended, the magnetic head is moved to the next track, and the above steps are repeated.

Abstract: An electronic apparatus, such as a disk apparatus, has a plurality of electronic units such as magnetic head-disk units and at least one power source unit for supplying power to the electronic units. The arrangement of the electronic apparatus is such that, on a frame of the apparatus, the plurality of electronic units are vertically arranged in such a manner as to form a first arrangement system, while the at least one power source unit is arranged in such a manner as to form a second arrangement system above the first arrangement system. The apparatus has an air flow passage for causing cooling air to flow from a lower portion of the electronic apparatus to the inside thereof, pass through the first arrangement system, thereby pass through the second arrangement system, and then be discharged to the outside of the apparatus.

Abstract: Every other input pulse is extracted from an input signal containing alternate phase-advanced and phase-delayed pulses read out of a magnetic disk unit, a magnetic tape unit or the like. Output pulses in synchronism with the pulses thus extracted are produced. This extraction may be effected only during a predetermined length of time after staring application of the input pulses at the time of pull-in of a phase sync circuit. Whether phase synchronization is to be effected in accordance with advanced-phase or delayed-phase input pulses is determined from time to time as required.

Abstract: N-[1-(Thienyl)alkyl]amine derivative of the formula: ##STR1## which has excellent herbicidal activity against lowland annual weeds and upland weeds, can be prepared by reacting a thiophen derivative of the formula: ##STR2## with an aldehyde of the formula:ACHOand an amide of the formula:NH.sub.2 --CO--Rin the presence of formic acid or a mixture of formic acid with phosphoric acid wherein Z is halogen, alkyl or alkoxy group; (n) is 0, 1 or 2; A is hydrogen or alkyl group; R is alkyl group, group of the formula: ##STR3## in which X and Y are hydrogen, alkyl group, haloalkyl group, alkoxy group, alkoxymethyl group or halogen, or group of the formula: ##STR4## in which Z and (n) are the same as defined above.

Abstract: This invention provides a magnetic disk device having a total memory capacity of 30 giga bytes or more, or more desirably 30.about.40 giga bytes. The magnetic disk used in this magnetic disk device has a plane record density of 45.about.80 mega bits per square inch. The thin film magnetic head has a pole thickness (P.sub.T), a magnetic flux density (B.sub.s), a magnetic gap depth (G.sub.d) and a record wavelenth (.lambda.) which satisfy the formulaG.sub.d .ltoreq.0.13 P.sub.T B.sub.s (.lambda.+4.3)-2.1.The magnetic disk rotation means rotate the magnetic disk at a speed of 24 m per second or more.

Abstract: Because of increase in data recording density on a magnetic disk in recent years, a minute defect which posed no problem in the past exerts adverse influence upon the recording and reproducing characteristics. An object of the present invention is to provide a method and an apparatus for detecting minute defects on a magnetic disk. In order to achieve this object, the present invention was made on the basis of the recognition that a large defect on the magnetic disk largely decreases the amplitude of the reproduced signal and shifts its phase, whereas a small defect does not decrease the amplitude of the reproduced signal so largely but causes a phase shift. Therefore, defects on the magnetic disk are detected by monitoring the amplitude decrease and phase shift of the reproduced signal.