Abstract: A thin film magnetic head for perpendicular recording of a single-pole type has a flux enhanced part and a flux enhanced end of a main pole arranged on a leading side of the main pole in parallel with the cross track direction. The side surface of the main pole intersecting the cross track direction of the main pole is arranged on the track center side perpendicular to the track width. The field gradient of a perpendicular magnetic field on the trailing side of the main pole and near both ends of the track is made steep to realize a higher areal recording density as a result.

Abstract: A magnetic head for perpendicular recording without writing from the lateral sides of a mains pole and without erasing data on adjacent tracks. A magnetic disk storage apparatus using the magnetic head. The lateral side of the main pole of a magnetic head for perpendicular recording may have an inverted tapered shape obtained by forming a groove as a track portion to an inorganic insulating layer and then forming a magnetic layer and then flattening the upper surface. A leading edge, a trailing edge, or both lateral edges of the magnetic head may be tapered. The taper may be either smooth and linear or curved in profile.

Abstract: Thin film perpendicular magnetic head with a narrow main pole capable of a high recording density in excess of 100 gigabits per square inch and generating a high magnetic recording field exceeding 10 kOe (oersted), while also modified to suppress remanent magnetic fields occurring immediately after writing operation. In a perpendicular magnetic head comprising a main pole, a return path for supplying a magnetic flux to that main pole, and an conductive coil for excitation of the main pole and return path, the main pole has a pole width of 200 nanometers or less, and a magnetic multilayer made up of a high saturation flux density layer and low saturation flux density layer, the low saturation flux density layer has a thickness within 0.5 to 5 nanometers, the high saturation flux density layer has a thickness from 10 to 50 nanometers for suppressing remanent magnetization and preventing erasing after writing by utilizing a closed magnetic domain structure in the pole.

Abstract: A single pole type magnetic head has a writing head including a main pole and an auxiliary pole, and a reading head including a read element, wherein the main pole has a recess on the trailing side of its air bearing surface. When recording is performed on a perpendicular medium by using the single pole type magnetic head, the magnetic field distribution on the trailing side of the main pole air bearing surface is linearized, whereby the magnetic reversal is determined. As a result, a bit is recorded without curving the shape of magnetic reversal. Accordingly, when the bit is read, the magnetic reversal width appears to be large, so that the half-width of a solitary wave is increased, and at the same time, the recording track width is narrowed with an increase in linear recording density.

Abstract: To make a soft magnetic underlayer of a double layered perpendicular magnetic recording medium thinner than heretofore while avoiding saturation. Assuming that Tb1 is the thickness of the soft magnetic underlayer of the double layered perpendicular magnetic recording medium, BS2 the saturation flux density of the same, Tm the thickness of a magnetic recording head's main pole 1 along a track direction in the vicinity of its floating surface, TWW the track width of the same, and BS1 the saturation flux density of the same, then Tb1<(BS1×Tm×TWW)/2(BS2×(Tm+TWW)) is satisfied.

Abstract: A magnetic head for perpendicular recording without writing from the lateral sides of a main pole and without erasing data on adjacent tracks. A magnetic disk storage apparatus using the magnetic head. The lateral side of the main pole of a magnetic head for perpendicular recording may have an inverted tapered shape obtained by forming a groove as a track portion to an inorganic insulating layer and then forming a magnetic layer and then flattening the upper surface. A leading edge, a trailing edge, or both lateral edges of the magnetic head may be tapered. The taper may be either smooth and linear or curved in profile.

Abstract: A magnetic head is composed to diminish disordered writing bits of a recording layer or reading noise caused by a magnetic field generated from an under layer without decreasing a writing magnetic field strength of the magnetic head. The magnetic head includes a write head provided with a main pole and one or more auxiliary poles, a read head provided with a read element, and coils located on both sides of the main pole in a manner to sandwich the main pole. The coil located on one side generates the asymmetrical magneto-motive force for magnetizing the main pole to that generated by the coil located on the other side.

Abstract: The invention provides a magnetic head for perpendicular recording capable of recording with high linear recording density and high track density, and a magnetic disk drive incorporating the same. In order to achieve this, one or more sides of the main pole of the magnetic head for perpendicular recording except for the trailing side are formed in a taper with an appropriate angle against the tip surface of the main pole, and the yoke whose widest principal plane is in parallel to the tip surface is provided on the bottom of the main pole.

Abstract: In a thermal assisted type magnetic disk apparatus having a head holding a heat element and a write element, in which coercivity of a disk is locally reduced by temperature-increasing the disk and writing is performed by the write element, along with a seek operation to move the head by a rotary actuator in a radial direction, a yaw angle is changed and a heat area and the write element are track-shifted. A mechanism to offset one of the heat area and the write element in a width direction of a slider, to array the heat element and the write element in a track running direction in correspondence with the yaw angle of the head.

Abstract: To make a soft magnetic underlayer of a double layered perpendicular magnetic recording medium thinner than heretofore while avoiding saturation. Assuming that Tb1 is the thickness of the soft magnetic underlayer of the double layered perpendicular magnetic recording medium, BS2 the saturation flux density of the same, Tm the thickness of a magnetic recording head's main pole 1 along a track direction in the vicinity of its floating surface, TWW the track width of the same, and BS1 the saturation flux density of the same, then Tb1<(BS1×Tm×TWW)/2(BS2×(Tm+TWW)) is satisfied.

Abstract: In the PRML signal processing technique, reduction of data detection error events caused due to medium noise that occurs depending on a recording code data pattern is realized by using simple means. With respect to a detection data result obtained after PRML data demodulation, a code error event that depends on a signal distance and has a high frequency of occurrence is noticed and its occurrence probability is estimated. At this time, a locally existing medium noise quantity is estimated from preceding and subsequent code patterns of the PRML detection data result. Thereby the occurrence probability of the error event is compensated to improve the detection precision. As a result, data modulation with reliability higher than conventional maximum likelihood detection can be realized with a simple circuit structure.

Abstract: A single-pole type magnetic head for perpendicular recording which reduces the amount of side writing even in the presence of a yaw angle and prevents the effective track width from decreasing, and a magnetic recording disk apparatus using the same. A main pole is composed of at least two portions where the width of the first portion continuously increases from the upstream side to the downstream side in the medium moving direction and the width of the second portion is the same as the width of the first portion's downstream edge in the medium moving direction and is constant from the upstream side to the downstream side in the medium moving direction. This prevents the recording magnetic field strength from decreasing at the track edge and increases the effective track width while suppressing side writing, thereby realizing a magnetic recording disk apparatus with a high track density.

Abstract: A vertical magnetic recording apparatus is provided which can diminish thermal decay of magnetization to ensure a high reliability of the life of recorded information and which can stably effect the write of magnetic information. Light assist is performed by obliquely applying light to a gap between a main pole of a vertical recording head and a medium. The light is radiated from the head side of the apparatus with respect to the medium. Utilizing the present invention, the thermal decay of magnetization at room temperature is diminished, the life of the recorded information is increased, and the storage reliability of the disk is increased.

Abstract: Arrangement of the flux enhanced part and the flux enhanced end of a main pole and the front or side surface of the main pole of a single-pole head for perpendicular recording is considered to prevent the influence of the leakage magnetic field from those parts and to enhance a field gradient in a portion for writing the boundary of a bit cell into a recording layer in a profile of a perpendicular magnetic field. A flux enhanced part 26 and a flux enhanced end 39 of a main pole are arranged on a leading side 25 rather than a vertical plane 36 in parallel with the cross track direction including the trailing edge of an air bearing surface of the main pole. Further, the front surface on the trailing side of the main pole is arranged on the leading side rather than the vertical plane.

Abstract: When recording is performed on a perpendicular medium by using a single pole type head, there emerges a problem that the shape of magnetic transition is curved with respect to the track width direction due to the distribution of head write field. If the shape of magnetic transition is curved, there occur problems as follows: when reading is performed by a magnetoresistive head, the magnetic transition length appears to be large, so that the half-width of an isolated pulse is increased, and at the same time, the recording track width seems to be reduced with an increase in linear recording density. In the side on the trailing side of a main pole air bearing surface of a magnetic head for perpendicular recording, the central portion is situated closer to the leading side than the corners on the trailing side. In other words, the main pole air bearing surface is formed in the shape of a recess with respect to the tailing side.

Abstract: A magnetic head for perpendicular recording without writing from the lateral sides of a main pole and without erasing data on adjacent tracks. A magnetic disk storage apparatus using the magnetic head. The lateral side of the main pole of a magnetic head for perpendicular recording may have an inverted tapered shape obtained by forming a groove as a track portion to an inorganic insulating layer and then forming a magnetic layer and then flattening the upper surface. A leading edge, a trailing edge, or both lateral edges of the magnetic head may be tapered. The taper may be either smooth and linear or curved in profile.

Abstract: To make a soft magnetic underlayer of a double layered perpendicular magnetic recording medium thinner than heretofore while avoiding saturation. Assuming that Tb1 is the thickness of the soft magnetic underlayer of the double layered perpendicular magnetic recording medium, BS2 the saturation flux density of the same, Tm the thickness of a magnetic recording head's main pole 1 along a track direction in the vicinity of its floating surface, TWW the track width of the same, and BS1 the saturation flux density of the same, then Tb1<(BS1×Tm×TWW) / 2 (BS2×(Tm+TWW) ) is satisfied.

Abstract: A signal-pickup cartridge is adapted to be loaded into a holder of a signal-pickup device proper of a rotating recording medium reproducing apparatus. The signal-pickup cartridge comprises a cantilever having at its distal tip a reproducing element for picking up and reproducing a signal from a rotating recording medium rotating in the apparatus, a cartridge case supporting therewithin the cantilever and having a ceiling plate and vertical walls on opposite sides thereof, a box-shaped cover joinable to the cartridge case to cover the lower face thereof in a manner to protect the cantilever and the reproducing element, and a mechanism for joining the cover and the case in latched state. This mechanism is triggered to unlatch the cover from the case when the cartridge is inserted into the holder.

Abstract: A rotary recording medium reproducing apparatus for reproduces a rotary recording medium accommodated within a case. The case comprises a jacket provided with a space for accommodating the rotary recording medium and an opening for allowing the rotary recording medium to go in and out of the jacket, and a lid member inserted through the opening of the jacket for closing the opening of the jacket. The rotary recording medium reproducing apparatus has a rotary recording medium clamping mechanism provided at an innermost part of the reproducing apparatus, for clamping an outer peripheral groove guard of the rotary recording medium when the case is inserted into the reproducing apparatus and then the jacket is pulled out from the reproducing apparatus.

Abstract: A rotary recording medium reproducing apparatus reproduces a rotary recording medium accommodated within a case, where the case comprises a jacket provided with a space for accommodating the rotary recording medium and an opening for allowing the rotary recording medium to go in and out of the jacket, and a lid member inserted through the opening of the jacket for closing the opening of the jacket.