Abstract: According to one embodiment, a recording-current supplying section configured to supply a recording current used to excite a magnetic pole to thereby make a magnetic flux flow through the magnetic pole, supplies higher recording currents to those of a plurality of magnetic heads, located more outwardly in a direction along a same axis of rotation, as compared to ones of the plurality of magnetic heads, located closer to a middle position of an interval between the magnetic disks arranged at both ends in the direction along the same axis of rotation.

Abstract: According to one embodiment, among a plurality of magnetic heads, the larger the magnetic pole width of the magnetic pole of the magnetic head in the width direction of a recording track formed in a recording layer or the larger an area width of the magnetic head capable of reading the magnetic characteristics of an area of the recording layer on which magnetic recording has been carried out by means of the magnetic head, the farther is the magnetic head arranged outwardly from the vicinity of the center in the parallel arrangement direction of the magnetic disks.

Abstract: An image forming apparatus performs the following. An imaging range imaged by each of the plurality of imaging sensors includes an overlapping portion between the imaging sensors adjacent in a width direction orthogonal to a conveying direction along the conveying path. A hardware processor performs a calibration operation of a first sensor based on a color measuring result of a predetermined inspection image measured within a standard imaging range of the first sensor among the plurality of imaging sensors, and a standard imaging result within the standard imaging range imaging an inspection image with a same pattern as the inspection image. The hardware processor compares imaging results by the plurality of imaging sensors in the overlapping portions and performs the calibration operation of another sensor different from the first sensor using the standard imaging result as a standard.

Abstract: According to one embodiment, a magnetic disk device includes magnetic disks, a plurality of magnetic heads, and a control unit. A plurality of magnetic heads each includes a heat-assist unit which applies a preheating current of such magnitude that data already written to the magnetic disk is not erased to a near-field optical element for the preheat time. The control unit measures the time elapsing from a start of write to the time when a value of an index indicating the quality of a recording signal of data written by the magnetic head converges to within a first threshold range, and adjusts the preheat time for each of the magnetic heads in such a manner that the measured lapse time becomes less than or equal to a second threshold.

Abstract: According to one embodiment, among a plurality of magnetic heads, the larger the magnetic pole width of the magnetic pole of the magnetic head in the width direction of a recording track formed in a recording layer or the larger an area width of the magnetic head capable of reading the magnetic characteristics of an area of the recording layer on which magnetic recording has been carried out by means of the magnetic head, the farther is the magnetic head arranged outwardly from the vicinity of the center in the parallel arrangement direction of the magnetic disks.

Abstract: An image forming apparatus performs the following. An imaging range imaged by each of the plurality of imaging sensors includes an overlapping portion between the imaging sensors adjacent in a width direction orthogonal to a conveying direction along the conveying path. A hardware processor performs a calibration operation of a first sensor based on a color measuring result of a predetermined inspection image measured within a standard imaging range of the first sensor among the plurality of imaging sensors, and a standard imaging result within the standard imaging range imaging an inspection image with a same pattern as the inspection image. The hardware processor compares imaging results by the plurality of imaging sensors in the overlapping portions and performs the calibration operation of another sensor different from the first sensor using the standard imaging result as a standard.

Abstract: According to one embodiment, a magnetic disk device includes magnetic disks, a plurality of magnetic heads, and a control unit. A plurality of magnetic heads each includes a heat-assist unit which applies a preheating current of such magnitude that data already written to the magnetic disk is not erased to a near-field optical element for the preheat time. The control unit measures the time elapsing from a start of write to the time when a value of an index indicating the quality of a recording signal of data written by the magnetic head converges to within a first threshold range, and adjusts the preheat time for each of the magnetic heads in such a manner that the measured lapse time becomes less than or equal to a second threshold.

Abstract: According to one embodiment, among a plurality of magnetic heads, the larger the magnetic pole width of the magnetic pole of the magnetic head in the width direction of a recording track formed in a recording layer or the larger an area width of the magnetic head capable of reading the magnetic characteristics of an area of the recording layer on which magnetic recording has been carried out by means of the magnetic head, the farther is the magnetic head arranged outwardly from the vicinity of the center in the parallel arrangement direction of the magnetic disks.

Abstract: According to one embodiment, among a plurality of magnetic heads, the larger the magnetic pole width of the magnetic pole of the magnetic head in the width direction of a recording track formed in a recording layer or the larger an area width of the magnetic head capable of reading the magnetic characteristics of an area of the recording layer on which magnetic recording has been carried out by means of the magnetic head, the farther is the magnetic head arranged outwardly from the vicinity of the center in the parallel arrangement direction of the magnetic disks.

Abstract: According to one embodiment, a magnetic disk device includes a disk that includes a first track, a head that includes a heater, writes data to the disk, and reads data from the disk, and a controller configured to set a variation of a parameter related to a write process for the disk within one round of the first track to suppress a variation of an evaluation index corresponding to a write/read processing characteristic within one round of the first track.

Abstract: According to one embodiment, a magnetic disk device includes a disk that includes a first track, a head that includes a heater, writes data to the disk, and reads data from the disk, and a controller configured to set a variation of a parameter related to a write process for the disk within one round of the first track to suppress a variation of an evaluation index corresponding to a write/read processing characteristic within one round of the first track.

Abstract: According to one embodiment, a magnetic recording and reproducing device includes a perpendicular magnetic recording medium, a perpendicular magnetic recording head, a thermal assisted magnetic recording medium, and a thermal assisted magnetic recording head.

Abstract: According to one embodiment, a magnetic disk device includes a disk, a head including a read head that reads data from the disk, a write head that writes data into the disk, and an assist element that generates energy for improving write performance of the write head, and a controller that adjusts a degauss condition after a stop of a write process of the write head, based on a resistance value of the assist element, and adjusts a data format of the disk in accordance with the degauss condition, the resistance value being measured after data is written into the disk, and the write process having an influence on the resistance value.

Abstract: According to one embodiment, a magnetic recording and reproducing device includes a perpendicular magnetic recording medium, a perpendicular magnetic recording head, a thermal assisted magnetic recording medium, and a thermal assisted magnetic recording head.

Abstract: An image forming apparatus performs the following. An imaging range imaged by each of the plurality of imaging sensors includes an overlapping portion between the imaging sensors adjacent in a width direction orthogonal to a conveying direction along the conveying path. A hardware processor performs a calibration operation of a first sensor based on a color measuring result of a predetermined inspection image measured within a standard imaging range of the first sensor among the plurality of imaging sensors, and a standard imaging result within the standard imaging range imaging an inspection image with a same pattern as the inspection image. The hardware processor compares imaging results by the plurality of imaging sensors in the overlapping portions and performs the calibration operation of another sensor different from the first sensor using the standard imaging result as a standard.

Abstract: According to one embodiment, a magnetic disk device includes a disk having a first area, and a second area to which data is temporary written, a head including a write head which writes data to the disk, and an assisting element which generates energy which improves write performance of the write head, and a controller which writes data to the first area by supplying energy having a first value to the assisting element, and writes data to the second area by supplying energy having a second value different from the first value to the assisting element.

Abstract: According to one embodiment, a magnetic disk device includes a disk, a head including a read head that reads data from the disk, a write head that writes data into the disk, and an assist element that generates energy for improving write performance of the write head, and a controller that adjusts a degauss condition after a stop of a write process of the write head, based on a resistance value of the assist element, and adjusts a data format of the disk in accordance with the degauss condition, the resistance value being measured after data is written into the disk, and the write process having an influence on the resistance value.

Abstract: An image forming apparatus performs the following. An imaging range imaged by each of the plurality of imaging sensors includes an overlapping portion between the imaging sensors adjacent in a width direction orthogonal to a conveying direction along the conveying path. A hardware processor performs a calibration operation of a first sensor based on a color measuring result of a predetermined inspection image measured within a standard imaging range of the first sensor among the plurality of imaging sensors, and a standard imaging result within the standard imaging range imaging an inspection image with a same pattern as the inspection image. The hardware processor compares imaging results by the plurality of imaging sensors in the overlapping portions and performs the calibration operation of another sensor different from the first sensor using the standard imaging result as a standard.

Abstract: According to one embodiment, among a plurality of magnetic heads, the larger the magnetic pole width of the magnetic pole of the magnetic head in the width direction of a recording track formed in a recording layer or the larger an area width of the magnetic head capable of reading the magnetic characteristics of an area of the recording layer on which magnetic recording has been carried out by means of the magnetic head, the farther is the magnetic head arranged outwardly from the vicinity of the center in the parallel arrangement direction of the magnetic disks.

Abstract: An image forming apparatus performs the following. An imaging range imaged by each of the plurality of imaging sensors includes an overlapping portion between the imaging sensors adjacent in a width direction orthogonal to a conveying direction along the conveying path. A hardware processor performs a calibration operation of a first sensor based on a color measuring result of a predetermined inspection image measured within a standard imaging range of the first sensor among the plurality of imaging sensors, and a standard imaging result within the standard imaging range imaging an inspection image with a same pattern as the inspection image. The hardware processor compares imaging results by the plurality of imaging sensors in the overlapping portions and performs the calibration operation of another sensor different from the first sensor using the standard imaging result as a standard.