Patent application number | Description | Published |
20090059436 | THIN-FILM MAGNETIC HEAD HAVING CPP STRUCTURE MAGNETO-RESISTIVE EFFECT DEVICE - The invention provides a thin-film magnetic head having a magneto-resistive effect device of the CPP (current perpendicular to plane) structure comprising a multilayer film in which a fixed magnetization layer, a nonmagnetic layer and a free layer are stacked together in order. The fixed magnetization layer, nonmagnetic layer and free layer extend rearward from an air bearing surface that is a plane in opposition to a medium, the length of the depth-wise side of the fixed magnetization layer is longer than that of the free layer, and a shunt layer for shunting a sense current is formed more on the depth-wise side of, and kept constantly away from, the free layer. There are thus much more favorable advantages obtained: even when device size is further reduced and narrowed, degradation of frequency characteristics is hold back, any increase in the thermal magnetic noise is stayed off, and performance fluctuations are minimized. | 03-05-2009 |
20090256557 | TESTING METHOD OF MAGNETIC HEAD BY USING INDUCTANCE - It is an object of the present invention to provide a method for investigating magnetic domains, the method capable of easily grasping behavior of the magnetic domains in a head manufacturing process, and further to provide a testing method of a magnetic head capable of evaluating whether the writing performance of the magnetic head is good or not. The method for investigating magnetic domains comprises supplying direct current (DC) to a coil of an electromagnetic transducer provided in a magnetic head for writing data onto a magnetic recording medium; measuring an inductance of the electromagnetic transducer at each current value while varying the current value of the direct current; and investigating behavior of magnetic domains in a magnetic core of the electromagnetic transducer based on a relationship between the current values and the inductances. The testing method of a magnetic head comprises evaluating whether writing performance of the magnetic head is good or not, based on a relationship between the current values and the inductances. | 10-15-2009 |
20090323209 | METHOD FOR MEASURING MAGNETIC WRITE WIDTH IN DISCRETE TRACK RECORDING - A method of measuring a magnetic write width of a magnetic head MWW | 12-31-2009 |
20110122533 | Magnetic disk device having mechanism for detecting projections on recording medium - A thin film magnetic head includes a medium projection detection mechanism that detects a projection on the surface of a recording medium. The medium projection detection mechanism has a discharging electrode, a capacitor, and an input line and an output line that are connected to the discharging electrode. The discharging electrode is configured to receive a voltage applied through the input line, and the capacitor is configured to store electric charge by the applied voltage. The output line is connected to a projection detection processing system and is connected to the charging electrode and the projection detection processing system to detect the location of the projection that is a detection target by detecting voltage change that is caused by discharging between the discharging electrode and the projection when the projection is detected. | 05-26-2011 |
20110206729 | MUCOSAL VACCINE USING CATIONIC NANOGEL - A mucosal vaccine for the prevention or treatment of microbial infections is described that is capable of inducing vaccine antigen-specific immune responses in an organism without the addition of a mucosal adjuvant. The mucosal vaccine comprises a composite of a nanogel comprising a hydrophilic polysaccharide having a cationic functional group and a hydrophobic cholesterol added thereto as a side chain and a vaccine antigen. The vaccine is administered via a mucosal route. | 08-25-2011 |
20120230169 | THERMALLY-ASSISTED MAGNETIC RECORDING METHOD FOR WRITING DATA ON A HARD DISK MEDIUM - A thermally-assisted magnetic recording method includes first and second steps. The first step applies heat to part of a hard disk medium and forms a moving high-temperature region in a magnetic recording layer of the hard disk medium. The high-temperature region is higher in temperature than a region therearound and has a temperature equal to or higher than the maximum coercivity vanishing temperature of a plurality of magnetic grains contained in the magnetic recording layer. At least one magnetic grain that is adjacent to the rear end of the high-temperature region in the direction of movement of the high-temperature region has a coercivity of a value other than 0. The second step applies a write magnetic field to the hard disk medium such that the write magnetic field applied to the at least one magnetic grain adjacent to the rear end of the high-temperature region is 3 kOe or smaller in magnitude. | 09-13-2012 |
20120232831 | METHOD OF ESTIMATING CURIE TEMPERATURE DISTRIBUTION IN A MAGNETIC RECORDING LAYER - In a method of estimating the Curie temperature distribution of a plurality of magnetic grains contained in a magnetic recording layer, measurement values of first and second parameters are obtained for each of different temperatures of the magnetic recording layer which is used as the measurement subject. The first parameter has such a property that the absolute value of the first parameter for each magnetic grain takes on the minimum value when the temperature of each magnetic grain reaches a predetermined temperature, wherein the predetermined temperature varies according to the Curie temperature of each magnetic grain in such a manner as to increase as the Curie temperature increases, and to decrease as the Curie temperature decreases. The second parameter is related to the standard deviation of the coervicity distribution of the magnetic grains divided by the coervicity of the magnetic recording layer. The method calculates a value related to the Curie temperature distribution, based on the lowest temperature at which the absolute measurement value of the first parameter takes on the minimum value and the temperature of the magnetic recording layer at which the standard deviation of the coervicity distribution of the magnetic grains divided by the coervicity of the magnetic recording layer takes on the maximum value, which is obtained from the measurement value of the second parameter. | 09-13-2012 |
20120236431 | MAGNETIC RECORDING DEVICE AND MAGNETIC RECORDING METHOD - A magnetic disk device includes: a recording medium provided with a plurality of write tracks; a magnetic write head including a magnetic pole, side shields, and a leading shield, a distance from the magnetic pole to each of the side shields being maintained to be uniform with a gap layer therebetween, and a distance from the magnetic pole to the leading shield being maintained to be uniform with a gap layer therebetween; and a control section rotating the recording medium, and allowing magnetic information to be recorded on the recording medium while allowing the magnetic write head to travel in a direction from an inner write track toward an outer write track or in a direction from the outer write track toward the inner write track, across write tracks in the recording medium. With such a configuration, format efficiency may be improved, and a width of an erase band on a magnetic disk may be minimized. Therefore, surface recording density of a recording medium may be improved without reducing an effective write track width. | 09-20-2012 |
20130044575 | METHOD FOR DETECTING PROTRUSION HEIGHT OF MAGNETIC HEAD SLIDER HAVING THERMALLY ASSISTED HEAD - A magnetic head slider includes a near-field light generator, an incorporated heater is activated to thermally-expand the magnetic head slider so that a first protrusion is generated on the air bearing surface, and a second protrusion protruding from the first protrusion is generated by a thermal expansion of the near-field light generator. A standard signal is written to a recording medium with a predetermined magnetization. A relation between a residual magnetization of the standard signal and a power of the heater is obtained by lowering the magnetization of the standard signal by heating the recording medium with the near-field light while light output of laser light is maintained to be constant and the power of the heater is varied. Further, a relation between the first spacing and the residual magnetization is obtained. A value of the first spacing is obtained as a protrusion height of the second protrusion from the first protrusion when the second protrusion contacts the recording medium, the value of the first spacing being determined where an absolute value of a change rate of the residual magnetization is less than a predetermined standard value. | 02-21-2013 |
20140370056 | Mucosal Vaccine Using Cationic Nanogel - A mucosal vaccine for the prevention or treatment of microbial infections is described that is capable of inducing vaccine antigen-specific immune responses in an organism without the addition of a mucosal adjuvant. The mucosal vaccine comprises a composite of a nanogel comprising a hydrophilic polysaccharide having a cationic functional group and a hydrophobic cholesterol added thereto as a side chain and a vaccine antigen. The vaccine is administered via a mucosal route. | 12-18-2014 |