The Research Institute for Electric and Magnetic Materials

Daido Steel Co., Ltd.

The Foundation: the Research Institute for Electric and Magnetic Materials

Kiwamu Shirakawa

Nobukiyo Kobayashi

Yasushi Kaneta

Takeshi Yano

Tsuyoshi Masumoto

Masaaki Yamamoto

Shigehiro Ohnuma

Hirofumi Imatani

Mamiko Naka

Yasushi Daido Steel Co Ltd Kaneta

A magnetic detection element includes a magnetoresistance effect portion composed of a magnetoresistance effect material and a pair of yoke portions. The pair of yoke portions is composed of a soft magnetic material and are respectively arranged so as to be electrically connected to both sides of the magnetoresistance effect portion. The pair of yoke portions guides magnetic flux into the magnetoresistance effect portion. The magnetic detection element also includes a bypass portion, which is composed of a soft magnetic material and is saturated with magnetic flux at lower magnetic field intensity than the yoke portions, and which guides a part of the magnetic flux generated in the yoke portions so as to divert the magnetic flux from the magnetoresistance effect portion.

Signal transmission device

A method of manufacturing a thin film magnetic sensor comprising: forming a projection on a surface of an insulating substrate formed of an insulating nonmagnetic material by removing an unnecessary portion of the insulating substrate from a surface region thereof or by depositing a thin film formed of an insulating nonmagnetic material on the surface of the insulating substrate; forming a pair of thin film yokes positioned to face each other with the projection interposed therebetween and completely electrically separated from each other, the thin film yokes being formed by depositing a thin film formed of a soft magnetic material on the surface of the insulating substrate having the projection formed thereon, followed by partially removing the thin film formed of the soft magnetic material until at least a tip surface of the projection is exposed to the outside; and depositing a GMR film having an electrical resistivity higher than that of the soft magnetic material on the tip surface of the projection and on upper surfaces of the thin film yokes contiguous to the projection such that the GMR film is electrically connected to the upper surfaces of the thin film yokes.

Methods for manufacturing a thin film magnetic sensor

A thin film magnetic sensor comprises a pair of thin film yokes each formed of a soft magnetic material, the thin film yokes being arranged to face each other with a gap interposed therebetween; a GMR film electrically connected to the pair of the thin film yokes and having an electrical resistivity higher than that of the soft magnetic material; and an insulating substrate supporting the thin film yokes and the GMR film and formed of an insulating nonmagnetic material. A gap column of a multilayer structure including a layer formed of an insulating nonmagnetic material and a layer of the GMR film is arranged within the gap, and the thickness of the GMR film is uniform over the gap length.

Thin film magnetic sensor and method of manufacturing the same

The magnetic north detecting device comprises: a 3-dimensional geomagnetism sensor unit including three geomagnetism sensors for detecting respective components of a geomagnetism magnetic field intensity in respective directions of three coordinate axes perpendicular to each other; and a 3-dimensional operation functional section for carrying out an operation on the basis of the components of the geomagnetism magnetic field intensity detected by the geomagnetism sensors, and calculating a magnetic north direction of the geomagnetism, and the 3-dimensional operation functional section carries out the operation and calculates the magnetic north direction of the geomagnetism, based on two assumptions that: (i) at least one axis of three coordinate axes of the 3-dimensional geomagnetism sensor unit is level to the earth surface; and (ii) an angle of a geomagnetism magnetic field vector which is calculated from the detected components of the geomagnetism magnetic field intensity, referring to the earth surface, coincides with a dip angle of the geomagnetism which is assumed beforehand.

Magnetic north detecting device and magnetic north detecting method

A thin-film magnetic field sensor is provided which includes two arms of a bridge circuit formed of a first element having a giant-magneto-resistant thin-film, and soft magnetic thin-films disposed one on either side thereof, with electrical terminals, and a second element having a giant-magneto-resistant thin-film, and conductive films disposed one on either side thereof, with electrical terminals. The electrical resistance value of the second element has sensitivity relative to the magnetic field, such that it is substantially zero when the magnetic field is small, but it changes equally to the first element due to causes other than the magnetic field. Since the output of the bridge circuit is in proportion to the difference in electrical resistance values between the first and second elements, part of a change due to causes other than the magnetic field is canceled in the output of the bridge circuit, whereby the magnetic field value can be accurately measured.

Growing community of inventors

Sendai, Japan

Kiwamu Shirakawa