Abstract: A measuring circuit system in a magnetic field measuring apparatus of the invention has an amplifier and a band-pass filter connected in sequence on an output terminal side of the TMR element, the band-pass filter is a narrow-range band-pass filter such that a peak pass frequency of the filter that is a center is a basic frequency selected from a range of 10 to 40 GHz and a band width centered around the basic frequency is a narrow range of ±0.5 to ±4 GHz; and with the measuring circuit system, an S/N ratio (SNR) of 3 dB or greater is obtained, the SNR being defined by a ratio of an amplitude S of a high-frequency generated signal induced by the TMR element to a total noise N that is a sum of a head noise generated by the TMR element and a circuit noise generated by the amplifier. With such a configuration, an in-plane high-frequency magnetic field generated by a microwave-assisted magnetic head is reliably and precisely measured.

Abstract: This magnetic recording device is provided with a magnetic write head having a magnetic pole, and a magnetic recording medium having a plurality of data recording blocks. Each of the data recording blocks is formed with a plurality of write tracks, and separated, in a write track width direction, from neighboring one of the data recording blocks with a writing exudation suppression section in between. With this configuration, a magnetic mutual interference of the adjacent data recording blocks at the time of a data rewriting process is avoided even when a mutual interval of the data recording blocks is narrowed, and a good recording state is maintained in each of the data recording blocks. Therefore, it is possible to achieve an improvement in a recording density, while realizing the good and brief data rewriting process for each of the data recording blocks.

Abstract: A measuring circuit system in a magnetic field measuring apparatus of the invention has an amplifier and a band-pass filter connected in sequence on an output terminal side of the TMR element, the band-pass filter is a narrow-range band-pass filter such that a peak pass frequency of the filter that is a center is a basic frequency selected from a range of 10 to 40 GHz and a band width centered around the basic frequency is a narrow range of ±0.5 to ±4 GHz; and with the measuring circuit system, an SIN ratio (SNR) of 3 dB or greater is obtained, the SNR being defined by a ratio of an amplitude S of a high-frequency generated signal induced by the TMR element to a total noise N that is a sum of a head noise generated by the TMR element and a circuit noise generated by the amplifier. With such a configuration, an in-plane high-frequency magnetic field generated by a microwave-assisted magnetic head is reliably and precisely measured.

Abstract: A microwave assisted magnetic head is formed to include a main pole magnetic layer including a main pole; a shielded magnetic layer including a shielded pole; a recording coil that is formed to generate a writing magnetic field from a tip of the main pole; and a microwave radiation waveguide made of a conductive nonmagnetic material that is disposed in a recording gap, the recording gap being a gap between the main pole and the shielded pole.

Abstract: A microwave assisted magnetic head is formed to include a main pole magnetic layer including a main pole; a shielded magnetic layer including a shielded pole; a recording coil that is formed to generate a writing magnetic field from a tip of the main pole; and a microwave radiation waveguide made of a conductive nonmagnetic material that is disposed in a recording gap, the recording gap being a gap between the main pole and the shielded pole.

Abstract: For obtaining a flying height of a magnetic head from a magnetic disk, the magnetic head being placed in a slider arranged at an interval with the magnetic disk, an initial setting process and a flying height detecting process are performed. In the initial setting process, driving power to a heater is increased gradually, from a state where the heater arranged at a position in proximity to the magnetic head in the slider is not driven, until the magnetic head makes contact with the magnetic disk. Then, in each stage, an electrical resistance value of the sensor arranged at a position in proximity to the magnetic head in the slider, which is increased due to the heat from heater, and either an approach distance of the magnetic head toward the magnetic disk or the flying height of the magnetic head from the magnetic disk are acquired.

Abstract: This magnetic recording device is provided with a magnetic write head having a magnetic pole, and a magnetic recording medium having a plurality of data recording blocks. Each of the data recording blocks is formed with a plurality of write tracks and separated, in a write track width direction, from neighboring one of the data recording blocks with a writing exudation suppression section in between. With this configuration, a magnetic mutual interference of the adjacent data recording blocks at the time of a data rewriting process is avoided even when a mutual interval of the data recording blocks is narrowed, and a good recording state is maintained in each of the data recording blocks. Therefore, it is possible to achieve an improvement in a recording density, while realizing the good and brief data rewriting process for each of the data recording blocks.

Abstract: A measuring circuit system in a magnetic field measuring apparatus of the invention has an amplifier and a band-pass filter connected in sequence on an output terminal side of the TMR element, the band-pass filter is a narrow-range band-pass filter such that a peak pass frequency of the filter that is a center is a basic frequency selected from a range of 10 to 40 GHz and a band width centered around the basic frequency is a narrow range of ±0.5 to ±4 GHz; and with the measuring circuit system, an SIN ratio (SNR) of 3 dB or greater is obtained, the SNR being defined by a ratio of an amplitude S of a high-frequency generated signal induced by the TMR element to a total noise N that is a sum of a head noise generated by the TMR element and a circuit noise generated by the amplifier. With such a configuration, an in-plane high-frequency magnetic field generated by a microwave-assisted magnetic head is reliably and precisely measured.

Abstract: A measurement circuit system of a magnetic field measurement apparatus of the present invention includes an amplifier, a mixer circuit and a band-pass filter that are connected in order on an output end side of a microstrip line or a coplanar wave guide, which is an in-plane high frequency magnetic field intensity measurement element, a frequency immediately before being inputted in the band-pass filter is down-converted by the mixer circuit to a frequency so that a band width of the band-pass filter can be used, the band-pass filter uses a narrow band of ±0.

Abstract: For obtaining a flying height of a magnetic head from a magnetic disk, the magnetic head being placed in a slider arranged at an interval with the magnetic disk, an initial setting process and a flying height detecting process are performed. In the initial setting process, driving power to a heater is increased gradually, from a state where the heater arranged at a position in proximity to the magnetic head in the slider is not driven, until the magnetic head makes contact with the magnetic disk. Then, in each stage, an electrical resistance value of the sensor arranged at a position in proximity to the magnetic head in the slider, which is increased due to the heat from heater, and either an approach distance of the magnetic head toward the magnetic disk or the flying height of the magnetic head from the magnetic disk are acquired.

Abstract: Provided is a magnetic reproducing method that enables a thin-film magnetic head including a head element for reading data signals which has a noise in its output due to a low temperature to bring out an excellent read characteristic in which the noise is suppressed even under the use environment with the low temperature. The magnetic reproducing method comprises the steps of: heating a head element for reading data signals which has a noise in its output due to a low temperature; and performing a read operation by using the head element for reading data signals under condition that the head element is increased in temperature.

Abstract: Provided is a method for testing a head element that enables proper evaluation of the head element based on a characteristic of the head element under high-temperature and high-stress conditions. The testing method can be performed on a thin-film magnetic head including a head element and a heating element capable of applying a heat and stress to the head element, or performed on a row bar or a substrate wafer on which a plurality of the head elements and a plurality of the heating elements are disposed. The testing method comprises the steps of: causing the heating element to generate heat to apply a heat and stress to the head element; and measuring a characteristic of the head element under the heat and stress to evaluate the head element.

Abstract: The head slider has a plurality of heaters each heating a corresponding region of the ABS, and a sensor detecting collision of the ABS with a projection on a surface of the magnetic disk. Currents supplied to the respective heaters are controlled and produce heats independently of one another. The heats produce projections on the corresponding regions of the ABS, respectively. The ABS with asperity can be planarized through appropriately controlling magnitude of the currents supplied to the heaters. Thus, the variation of a sensor output depending on asperity of the ABS is effectively reduced. Another head slider has a heater locally heating a corresponding region of the ABS. The heater has a structure where a central portion is away from the ABS compared with end portions, or a structure where calorific power of a central portion is smaller than that of each of end portions. Thus, overall projection shape becomes flat.

Abstract: A thin-film magnetic head comprises at least one of a magnetoresistive device for reading and an electromagnetic transducer device for writing, and a heating element provided in the head body part. The heating element has an up portion meandering between an origin and a halfway point and a down portion meandering along the up portion from the halfway point to an end positioned in the vicinity of the origin, and adapted to generate heat when energized.

Abstract: Provided is a magnetic reproducing method that enables a thin-film magnetic head including a head element for reading data signals which has a noise in its output due to a low temperature to bring out an excellent read characteristic in which the noise is suppressed even under the use environment with the low temperature. The magnetic reproducing method comprises the steps of: heating a head element for reading data signals which has a noise in its output due to a low temperature; and performing a read operation by using the head element for reading data signals under condition that the head element is increased in temperature.

Abstract: Provided is a method for testing a head element that enables proper evaluation of the head element based on a characteristic of the head element under high-temperature and high-stress conditions. The testing method can be performed on a thin-film magnetic head including a head element and a heating element capable of applying a heat and stress to the head element, or performed on a row bar or a substrate wafer on which a plurality of the head elements and a plurality of the heating elements are disposed. The testing method comprises the steps of: causing the heating element to generate heat to apply a heat and stress to the head element; and measuring a characteristic of the head element under the heat and stress to evaluate the head element.

Abstract: The head slider has a plurality of heaters each heating a corresponding region of the ABS, and a sensor detecting collision of the ABS with a projection on a surface of the magnetic disk. Currents supplied to the respective heaters are controlled and produce heats independently of one another. The heats produce projections on the corresponding regions of the ABS, respectively. The ABS with asperity can be planarized through appropriately controlling magnitude of the currents supplied to the heaters. Thus, the variation of a sensor output depending on asperity of the ABS is effectively reduced. Another head slider has a heater locally heating a corresponding region of the ABS. The heater has a structure where a central portion is away from the ABS compared with end portions, or a structure where calorific power of a central portion is smaller than that of each of end portions. Thus, overall projection shape becomes flat.

Abstract: A thin-film magnetic head comprises at least one of a magnetoresistive device for reading and an electromagnetic transducer device for writing, and a heating element provided in the head body part. The heating element has an up portion meandering between an origin and a halfway point and a down portion meandering along the up portion from the halfway point to an end positioned in the vicinity of the origin, and adapted to generate heat when energized.

Abstract: A thin-film magnetic head comprises at least one of a magnetoresistive device for reading and an electromagnetic transducer device for writing, and a heating element provided in the head body part. The heating element has an up portion meandering between an origin and a halfway point and a down portion meandering along the up portion from the halfway point to an end positioned in the vicinity of the origin, and adapted to generate heat when energized.

Abstract: A first magnetic film includes a first pole piece, and a second magnetic film includes a second magnetic piece. A gap film is disposed between the first pole piece and the second pole piece. The first magnetic film and the second magnetic film are magnetically joined with each other at a joint as viewed backward from the first pole chip and the second pole chip. A coil film winds vertically around the joint. Third magnetic films are disposed at both sides of the first pole piece or the second pole piece by a given distance.