Abstract: According to one embodiment, a magnetic disk device conforming to perpendicular magnetic recording includes a magnetic disk, a recording head, and a controller. The head includes a main magnetic pole, a return magnetic pole, a recording coil, and a conductive member in which end surfaces are connected to opposed surfaces of a write gap which is opposed to a distal portion of the main magnetic pole and a distal portion of the return magnetic pole, and a resistance value varies. The controller applies a current to the recording coil to excite the magnetic flux in the recording operation, and applies a current at a constant voltage to the magnetic circuit via the comductive member.

Abstract: According to one embodiment, a magnetic recording head includes a disk-facing surface, a main pole, a trailing shield, a first junction which connects the trailing shield and the main pole in a position off the disk-facing surface, a second junction which includes a high-frequency oscillator and connects the trailing shield and the main pole on side of the disk-facing surface, a leading shield on the leading side of the main pole, including a junction connected to the main pole in a position off the disk-facing surface with a third junction therebetween, and a connecting terminal configured to pass a current in series through the main pole, the nonmagnetic conductive layer, and the trailing shield. A thickness of the third junction is smaller than that of the first junction.

Abstract: According to one embodiment, a magnetic head includes a main pole, a write shield pole on a trailing side of the main pole, a recording coil, and a temperature control element unit. The temperature control element unit includes a first electrode on a leading side of the main pole and on both sides of a track of the main pole, a second electrode on the leading side of the main pole and on a track center of the main pole, an N-type semiconductor and a P-type semiconductor connected to the first and second electrodes, and a wiring portion which applies a current via the second electrode, N-type semiconductor, first electrode, P-type semiconductor, and second electrode. The first and second electrodes form a heat absorbing portion and a heat radiating portion.

Abstract: According to one embodiment, a magnetic recording head in a magnetic disk drive with a recording medium includes a magnetic core including a plurality of magnetic poles which form a closed magnetic path, and a recording coil wound around a part of the magnetic core and produces a magnetic field to the magnetic core. The magnetic core includes a write gap formed of a nonmagnetic material in a disk-facing surface of the recording head, a magnetic gap portion located at a position off from the disk-facing surface and magnetically isolated, and a nonmagnetic material in the at least one magnetic gap portion. The recording coil is wound around the nonmagnetic material in the magnetic gap portion.

Abstract: According to one embodiment, there is provided a magnetic recording head which records information on a magnetic recording medium, including an ABS surface, a near-field light generating unit, a heat conducting unit, and a heat absorbing unit. The ABS surface is opposed to the magnetic recording medium. The near-field light generating unit is disposed on the ABS surface. The heat conducting unit is formed by a heat conductor disposed in contact with the near-field light generating unit. The heat absorbing unit is disposed in contact with the heat conducting unit adjacently to the near-field light generating unit in a direction along the ABS surface.

Abstract: According to one embodiment, a magnetic head includes a main pole, a write shield pole on a trailing side of the main pole, a recording coil, and a temperature control element unit. The temperature control element unit includes a first electrode on a leading side of the main pole and on both sides of a track of the main pole, a second electrode on the leading side of the main pole and on a track center of the main pole, an N-type semiconductor and a P-type semiconductor connected to the first and second electrodes, and a wiring portion which applies a current via the second electrode, N-type semiconductor, first electrode, P-type semiconductor, and second electrode. The first and second electrodes form a heat absorbing portion and a heat radiating portion.

Abstract: According to one embodiment, there is provided a magnetic recording head which records information on a magnetic recording medium, including an ABS surface, a near-field light generating unit, a heat conducting unit, and a heat absorbing unit. The ABS surface is opposed to the magnetic recording medium. The near-field light generating unit is disposed on the ABS surface. The heat conducting unit is formed by a heat conductor disposed in contact with the near-field light generating unit. The heat absorbing unit is disposed in contact with the heat conducting unit adjacently to the near-field light generating unit in a direction along the ABS surface.

Abstract: According to one embodiment, a recording head includes a main pole, a trailing core, a first coil wound around the trailing core, a leading core, and a second coil wound around the leading core. The trailing core includes a return pole opposed to a trailing side of the main pole with a write gap therebetween, and side shields arranged individually on opposite sides of the main pole transversely relative to tracks and magnetically separated from the main pole at a distance not more than double a track pitch of the recording medium. The leading core includes a junction opposed to a leading side of the main pole with a gap therebetween and joined to the side shields with a width of 20 ?m or less transversely relative to the tracks and a connecting portion joined to the main pole in a position off the recording medium.

Abstract: According to one embodiment, a recording head includes a main pole, a trailing core, a first coil wound around the trailing core, a leading core, and a second coil wound around the leading core. The trailing core includes a return pole opposed to a trailing side of the main pole with a write gap therebetween, and side shields arranged individually on opposite sides of the main pole transversely relative to tracks and magnetically separated from the main pole at a distance not more than double a track pitch of the recording medium. The leading core includes a junction opposed to a leading side of the main pole with a gap therebetween and joined to the side shields with a width of 20 ?m or less transversely relative to the tracks and a connecting portion joined to the main pole in a position off the recording medium.

Abstract: According to one embodiment, a magnetic head includes a main pole configured to apply a perpendicular recording magnetic field to a recording layer of a recording medium, a return pole opposed to the trailing side of the main pole with a write gap therebetween and configured to reflux magnetic flux from the main pole to form a magnetic circuit in conjunction with the main pole, a coil configured to excite magnetic flux in the magnetic circuit includes the main pole and the return pole, a plurality of high-frequency oscillatory elements individually interposed between the main pole and the return pole, includes a plurality of magnetic films different in magnetic resonance frequency, and configured to individually apply high-frequency magnetic fields to the recording medium, and an electrical circuit configured to energize the high-frequency oscillatory elements.

Abstract: According to one embodiment, a magnetic recording head includes a flying surface and an exposed surface exposed on the flying surface. The exposed surface is defined by oblique sides and a lower side of a trapezoid having an upper side on the trailing side, and a contour line. The lower side on the leading side extends in parallel to the upper side and is shorter than the upper side. The contour line extends from one end to the other end of the upper side and rises from the upper side towards the trailing side between extended lines of the oblique sides.

Abstract: A magnetic recording device includes a patterned media magnetic recording medium where multiple tracks are arranged for radial direction in a concentric manner, the tracks each being formed by arranging multiple recording dots. The recording dots are each made of an isolated magnetic material and arranged in a rotational direction. The magnetic recording device further includes a magnetic head. The magnetic head includes: a main magnetic pole that faces the magnetic recording medium; a magnetic field generation coil that generates magnetic field to be transmitted to the magnetic recording medium through the main magnetic pole; a return yoke that receives the magnetic flux transmitted to the magnetic recording medium from the main magnetic pole and returns the magnetic flux thus received to the magnetic field generation coil; and a search coil that detects a change in magnetic flux passing through the return yoke.

Abstract: A write-head positioning method includes steps of positioning a write head on a first track of a storage medium on the basis of a servo signal and writing a signal on the first track, positioning the write head on second and third tracks located adjacent to opposite sides of the first track on the basis of servo signals and writing signals on the second track and the third track, positioning the read head at positions on the first track that are set at a predetermined interval in a track-width direction, and reading a signal from the first track at each position thereof, determining a signal profile that indicates a fluctuation of output values of the signals read at the respective positions on the first track, and detecting a peak position indicating a maximum output value in the determined signal profile.

Abstract: A write-head positioning method includes steps of positioning a write head on a first track of a storage medium on the basis of a servo signal and writing a signal on the first track, positioning the write head on second and third tracks located adjacent to opposite sides of the first track on the basis of servo signals and writing signals on the second track and the third track, positioning the read head at positions on the first track that are set at a predetermined interval in a track-width direction, and reading a signal from the first track at each position thereof, determining a signal profile that indicates a fluctuation of output values of the signals read at the respective positions on the first track, and detecting a peak position indicating a maximum output value in the determined signal profile.