Tdk Corporation

Akimasa Kaizu

Yoshikazu Soeno

Makoto Moriya

Shinji Hara

Naomichi Degawa

Eiji Komura

Naoki Ohta

Susumu Aoki

Tsutomu Aoyama

Kei Hirata

Tetsuya Roppongi

Katsumichi Tagami

Yosuke Antoku

Kazuya Shimakawa

Takekazu Yamane

Osamu Inoue

Tatsuhiro Kobayashi

Hayato Koike

Satoshi Tomikawa

Takayoshi Kuwajima

Tetsuhito Shinohara

A heat utilizing device is provided in which the thermal resistance of the wiring layer is increased while an increase in electric resistance of the wiring layer is limited. Heat utilizing device has thermistor whose electric resistance changes depending on temperature; and wiring layer that is connected to thermistor. A mean free path of phonons in wiring layer is smaller than a mean free path of phonons in an infinite medium that consists of a material of wiring layer.

Heat utilizing device

An electromagnetic wave sensor that limits the influence on bolometer membranes that is caused by heat from a local heat source is provided. Electromagnetic wave sensor has first substrate, second substrate that faces first substrate so as to form inner space between first substrate and second substrate, wherein second substrate transmits infrared rays; a plurality of bolometer membranes that is provided in inner space and that is supported by second substrate; local heat source that is formed in first substrate; first electric connection member that connects first substrate to second substrate; and lead that extends on or in second substrate and that connects first electric connection member to bolometer membrane.

Electromagnetic wave sensor

A high-frequency device includes a magnetoresistance effect element which includes a first ferromagnetic layer, a second ferromagnetic layer, and a spacer layer positioned between the first and second ferromagnetic layers, a soft magnetic material body which covers at least a part of a periphery of the magnetoresistance effect element from outside in a plan view in a lamination direction of the magnetoresistance effect element, a non-magnetic material body which is positioned between the soft magnetic material body and the first ferromagnetic layer in the plan view in the lamination direction, and a high-frequency line which is connected to or spaced apart from the magnetoresistance effect element. The high-frequency line is configured to input or output a high-frequency current to or from the magnetoresistance effect element, or is configured to apply a high-frequency magnetic field caused by a high-frequency current flowing through the inside to the magnetoresistance effect element.

High-frequency device

The magnetoresistance effect device includes: a magnetoresistance effect element that includes a first magnetization free layer, a magnetization fixed layer or a second magnetization free layer, and a spacer layer interposed between the first magnetization free layer and the magnetization fixed layer or the second magnetization free layer; and a magnetic material part that applies a magnetic field to the magnetoresistance effect element, wherein the magnetic material part is arranged to surround an outer circumference of the magnetoresistance effect element in a plan view in a stacking direction L of the magnetoresistance effect element.

Magnetoresistance effect device

At least one magnetoresistance effect element and a magnetic field applying unit to apply a magnetic field to the magnetoresistance effect element, the magnetic field applying unit includes a first ferromagnetic material having a portion protruding to the magnetoresistance effect element side in a stacking direction of the magnetoresistance effect element, a second ferromagnetic material sandwiching the magnetoresistance effect element with the first ferromagnetic material, and a coil wound around the first ferromagnetic material, a first magnetization free layer of the magnetoresistance effect element has a portion free of overlapping with at least one of a second surface of the protruding portion on the magnetoresistance effect element side and a third surface of the second ferromagnetic material on the magnetoresistance effect when viewed in the stacking direction, and a center of gravity of the first magnetization free layer, positioned in a region connecting the second surface and the third surface.

A magnetic recording-reproducing head includes, on a support member, a first head section having a function of executing a recording process and having a function of executing a reproducing process, and one or more second head sections each having a function of executing an erasing process and having no function of executing a reproducing process.

Magnetic recording-reproducing head having different sections with different functions including an erase function

A magnetic recording and reproducing apparatus includes a magnetic recording medium including a recording layer in which at least two magnetic layers are layered on a non-magnetic substrate; and a magnetic head including a main magnetic pole for applying a recording magnetic field in a direction substantially perpendicular to a recording face of the magnetic recording medium and a microwave generating element that generates a microwave magnetic field. The relationship between a thickness Ts of a magnetic layer having a lowest magnetic anisotropy energy among the at least two magnetic layers composing the recording layer of the magnetic recording medium, and a thickness Tt of the recording layer is Ts/Tt&#x2266;0.2. The microwave generating element applies the microwave magnetic field having a width broader than the width of the recording magnetic field generated by the main magnetic pole of the magnetic head to the magnetic recording medium.

Magnetic recording and reproducing apparatus

A magnetic recording apparatus includes a magnetic recording medium that is provided with a first magnetic layer with magneto crystalline anisotropy energy, a second magnetic layer with magneto crystalline anisotropy energy that is smaller than the magneto crystalline anisotropy energy of the first magnetic layer, and a nonmagnetic metal layer that is positioned between the first magnetic layer and the second magnetic layer and that provides coupling force between the first magnetic layer and the second magnetic layer; and a magnetic head that includes a main pole that applies a recording magnetic field in a direction perpendicular to a film surface of the magnetic recording medium to the magnetic recording medium, and an alternate current (AC) magnetic field generator that applies an AC magnetic field with a frequency of 1-40 GHz to the magnetic recording medium.

Magnetic recording apparatus

A magnetic recording device includes a magnetic disk and a magnetic head that performs magnetic recording to the magnetic disk. The magnetic head includes a main magnetic pole layer and a microwave generating element. The magnetic recording device further includes a microwave generating element driving current control circuit. The microwave generating element driving current control circuit, during the magnetic recording, applies a microwave generating element driving current at a first current level to the microwave generating element for a period that is from at the latest a polarity reversal of the recording current before a subsequent polarity reversal of the recording voltage, and thereafter applies another microwave generating element driving current at a second current level, which is smaller than the first current level, to the microwave generating element, or stops the application of the another microwave generating element driving current until the polarity reversal of the recording voltage.

Microwave-assisted magnetic recording device and method using non-constant microwave

A magnetic head that writes information to a recording medium includes a magnetic pole layer that generates a writing magnetic field to the recording medium, a microstripline that is disposed in proximity to the magnetic pole layer and to which high frequency current is applied, and a ferromagnetic thin film that is disposed on a portion of the microstripline that faces the recording medium, and that generates a high frequency alternate-current (AC) magnetic field to be applied to the recording medium, using a current magnetic field generated on the microstripline due to the high frequency current.

Magnetic head for microwave assisted magnetic recording

A magnetic recording-reproducing apparatus includes: a magnetic recording medium in which portions corresponding to track portions serve as recording areas and in which portions between the recording areas serve as non-recording areas; and a magnetic head having a main pole and a side shield disposed on both sides of the main pole in a cross-track direction. In the magnetic recording-reproducing apparatus, following inequality (I) is satisfied:/2+&#x2003;&#x2003;(I)where Tw is a track width, Gw is a gap width, and S is a distance between the center of the main pole of the magnetic head and an edge on the main pole side of each of the side shields.

Magnetic head and magnetic recording-reproducing apparatus

In the magnetic recording apparatus, a recording layer is formed in a concavo-convex pattern, and recording elements are formed of convex portions of the concavo-convex pattern. Furthermore, the following equation (I)+2&#xd7;&#x2003;&#x2003;(Equation (I))is satisfied in each of tracks, where Brepresents a length of the recording element in a circumferential direction, Grepresents a length of a gap between the recording elements in the circumferential direction, and Erepresents an effective recording length which is a length of an effective recording area Ein the circumferential direction, the effective recording area Ebeing created on a magnetic recording medium by a heating head and a recording head.

Magnetic recording apparatus and magnetic recording medium

The magnetic recording and reproducing apparatus includes: a perpendicular recording magnetic recording medium including a track pattern including track portions and gap portions arranged so as to be alternately adjacent to each other in a cross-track direction, at least part of portions corresponding to the track portions being recording areas having the width substantially the same as the width of the track portions, portions between the recording areas being non-recording areas; and a magnetic head of a perpendicular recording type for applying a recording magnetic field to the recording areas. The anisotropic magnetic field Hk (T) of the recording areas of the magnetic recording medium and the recording magnetic field intensity Fw (t) of the recording magnetic field at the upper surface of the recording areas satisfy the following inequality (I):0.23&#xd7;+1.2&#x2266;&#x2266;0.26&#xd7;+1.6.&#x2003;&#x2003;(I)

Magnetic recording and reproducing apparatus including a magnetic recording medium and a magnetic head for recording data on the magnetic recording medium

On a magnetic recording medium, M sets of burst patterns are formed along a direction of rotation of a substrate in each burst pattern region. Each burst pattern is formed so as to include two types of burst signal units that have an equal length along a radial direction of the substrate. In a predetermined range (2&#xb7;M) centers in the radial direction of the burst patterns are present at intervals of (1/N) times the track pitch in the radial direction. The predetermined range has a length along the radial direction of (2M/N) times the track pitch. M or N is a natural number of two or higher. The two types of burst signal units are formed of non-recording regions and facing end parts in the radial direction of the first type of burst signal units and the second type of burst signal units are separated via recording regions.

Magnetic recording medium, recording/reproducing apparatus, and stamper

On a magnetic recording medium, M sets of burst patterns are formed along a direction of rotation of a substrate in each burst pattern region. Each burst pattern is formed so as to include two types of burst signal units that have an equal length along a radial direction of the substrate. In a predetermined range, (2M) centers in the radial direction of the burst patterns are present at intervals of (1/N) times the track pitch in the radial direction. The predetermined range has a length along the radial direction of (2M/N) times the track pitch. M or N is a natural number of 2 or higher. The two types of burst signal units are formed of non-recording regions and end regions of the burst signal units overlap in the radial direction in at least one part region of the substrate.

Growing community of inventors

Tokyo, Japan

Akimasa Kaizu