Alps Green Devices Co., Ltd.

Mitsuo Aratono

Akira Takahashi

Masamichi Saito

Yosuke Ide

Yoshihiro Nishiyama

Kenji Ichinohe

Masahiro Iizuka

Hiroyuki Hebiguchi

Isao Sato

Shinji Mitsuya

Shigenobu Miyajima

Takashi Fujisaki

Masato Nakamura

A current sensor includes a magnetic sensor module including a plurality of magnetic sensor units connected in series. The magnetic sensor units each include a first magnetic sensor element and a second magnetic sensor element which have sensitivity axes oriented in opposite directions. A first terminal of the first magnetic sensor unit is connected to a first potential source. A third terminal of the first magnetic sensor unit is connected to a second potential source. A second terminal and a fourth terminal of the last magnetic sensor unit are connected to constitute a sensor output terminal. The first terminal of each of the magnetic sensor units excluding the first magnetic sensor unit is connected to the second terminal of the next magnetic sensor unit and the third terminal thereof is connected to the fourth terminal of the next magnetic sensor unit.

Current sensor

A current sensor includes first and second magnetic sensors that are placed around a current line through which a current flows so that the current line is positioned therebetween, and that detect an induction field generated by the current. Each of the first and second magnetic sensors has a main sensitivity axis and a sub-sensitivity axis. The direction of the main sensitivity axis of each of the first and second magnetic sensors is oriented in a direction that is not orthogonal to the direction of the induction field. The directions of the main sensitivity axes of the first and second magnetic sensors are oriented in the same direction and the directions of the sub-sensitivity axes are oriented in the same direction, or the directions of the main sensitivity axes are oriented in opposite directions and the directions of the sub-sensitivity axes are oriented in opposite directions.

A current sensor includes a substrate, a conductive body being provided above the substrate and extending in one direction, and magnetoresistance effect elements being provided between the substrate and the conductive body and outputting output signals owing to an induction magnetic field from a current to be measured being conducted through the conductive body, wherein each of the magnetoresistance effect elements has a laminated structure including a ferromagnetic fixed layer whose magnetization direction is fixed, a non-magnetic intermediate layer, and a free magnetic layer whose magnetization direction fluctuates with respect to an external magnetic field, the ferromagnetic fixed layer is a self-pinned type formed by antiferromagnetically coupling a first ferromagnetic film and a second ferromagnetic film through an antiparallel coupling film, the Curie temperatures of the first ferromagnetic film and the second ferromagnetic film are approximately equal, and a difference between the magnetization amounts thereof is substantially zero.

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Niigata-ken, Japan

Mitsuo Aratono