Tdk Corporation

Yohei Hirota

Hiraku Hirabayashi

Tsuyoshi Umehara

Hayato Miyashita

Yusuke Takahashi

Hiroshi Yamazaki

Homare Tokida

Hitoshi Iwama

Kazuya Watanabe

Naoki Ohta

Keisuke Uchida

Kunihiro Ueda

Masaki Nagata

Hiroshi Naganuma

A pair of bias magnets applies a bias magnetic field to the magneto-resistive effect element, the bias magnetic field having a component in a direction such that the component cancels the external magnetic field that is applied to the magneto-resistive effect element and a component that is perpendicular to the external magnetic field. The bias magnet has an elongate cross section in a plane that is parallel both to the external magnetic field and to the bias magnetic field. In a projection plane that is parallel to the cross section and onto which the bias magnets and the magneto-resistive effect element are projected, the bias magnet includes an element facing side that is opposite to the magneto-resistive effect element and that extends in a longitudinal direction. The bias magnet is magnetized in a direction that is perpendicular to the longitudinal direction. The element facing side is longer than other sides.

Magnetic sensor and camera module

A displacement detection apparatus includes a magnetic field generator, a first soft magnetic body, a second soft magnetic body, and a magnetic detection element. The magnetic field generator extends along a plane orthogonal to a first direction and includes a first portion and a second portion. The first soft magnetic body entirely overlaps the first portion in the first direction. The second soft magnetic body entirely overlaps the second portion in the first direction. The magnetic detection element is disposed in a region between the first soft magnetic body and the second soft magnetic body, and is configured to be subjected to a magnetic field generated by the magnetic field generator. The magnetic field generator, the first soft magnetic body, and the second soft magnetic body are provided to be integrally rotatable, with respect to the magnetic detection element, around a rotation axis extending in the first direction.

Displacement detection apparatus, displacement detection system, park lock system, and pedal system

A stack of electrical components has a first electrical component having a first surface, a second surface that is opposite to the first surface and a side surface that is located between the first surface and the second surface; a second electrical component having a third surface on which the first electrical component is mounted, the third surface facing the second surface and forming a corner portion between the third surface and the side surface; an adhesive layer that bonds the first electrical component to the second electrical component, the adhesive layer has a first portion that is located between the second and third surface and a second portion that is made of a same material as the first portion and that fills the corner portion; and a conductive layer that extends on a side of the side surface, curves along the second portion and extends to the third surface.

Stack of electrical components and method of producing the same

A stack of electrical components has a first electrical component having a first surface, a second surface that is opposite to the first surface and a side surface that is located between the first surface and the second surface; a second electrical component having a third surface on which the first electrical component is mounted, the third surface facing the second surface and forming a corner portion between the third surface and the side surface; an adhesive layer that bonds the first electrical component to the second electrical component, wherein the adhesive layer has a first portion that is located between the second surface and the third surface and a curved second portion that fills the corner portion; and a conductive layer that extends on a side of the side surface, curves along the second portion and extends to the third surface.

A rotation angle sensing device is provided with a magnet that is placed to be integrally rotatable with a rotary shaft of a rotating body in association with a rotating body, where the shape of the magnet as viewed along the rotary shaft is substantially circular; a magnetic sensor part that outputs a sensor signal based upon a change in a direction of a magnetic field in association with the rotation of the magnet; and a rotation angle detecting part that detects a rotation angle of the rotating body based upon the sensor signal output by the magnetic sensor part. The magnet has a component of a magnetization vector in a direction that is orthogonal to the rotation axis. When a circular virtual plane that is orthogonal to the rotary shaft centering upon the rotary shaft is set in the vicinity of the magnet, the magnetic sensor part is placed at a position where the amplitudes of the magnetic field intensity Hin the radial direction and the magnetic field intensity Ho in the circumferential direction on the virtual plane are substantially the same, and the magnetic field intensity Hin the radial direction and/or the magnetic field intensity Ho in the circumferential direction are/is output as the sensor signal.

Rotation angle sensing device

A first, a second, and a third computing circuit respectively generate a first post-computation signal with a second harmonic component reduced as compared with first and second signals, a second post-computation signal with the second harmonic component reduced as compared with third and fourth signals, and a third post-computation signal with the second harmonic component reduced as compared with fifth and sixth signals. A fourth and a fifth computing circuit respectively generate a fourth post-computation signal with a third harmonic component reduced as compared with the first and second post-computation signals, and a fifth post-computation signal with the third harmonic component reduced as compared with the second and third post-computation signals. A sixth computing circuit determines a detected angle value based on the fourth and fifth post-computation signals.

Rotating field sensor

A displacement detection unit includes a magnet and a magnetic detector. The magnet includes a first magnetic-pole region polarized into a south pole and a second magnetic-pole region polarized into a north pole, and generates a magnetic field around the magnet. The magnetic detector is movable relative to the magnet in a first direction, and detects a change in the magnetic field and thereby detects a displacement of the magnet in the first direction. The magnet includes a transition section in which a ratio of a magnetic volume of the second magnetic-pole region in a second direction to a magnetic volume of the first magnetic-pole region in the second direction gradually varies in the first direction. The second direction is orthogonal to the first direction.

Magnet and displacement detection unit

A magnetic field detection apparatus has a first magnetic sensor and a bias magnet positioned to face the first magnetic sensor. The bias magnet has a magnetic pole surface that faces the first magnetic sensor and that applies a bias magnetic field to the first magnetic sensor. The first magnetic sensor detects magnetic field in a first direction that is parallel to the magnetic pole surface. The magnetic pole surface of the bias magnet has a plurality of grooves arranged in the first direction.

Magnetic field detection apparatus and rotation detection apparatus

A rotating field sensor includes four detection circuits each of which generates an output signal responsive to the direction of a rotating magnetic field, and an angle calculation unit configured to calculate four angle values in correspondence to four groups each consisting of two detection circuits selected from the four detection circuits. The angle calculation unit calculates each of the four angle values on the basis of two output signals of the two detection circuits constituting a corresponding one of the four groups.

Rotating field sensor and angle determination method using the same

A rotating field sensor includes four detection circuits and a computing unit. In the computing unit, defined are four first detection circuit groups each consisting of three detection circuits. Further, defined in each first detection circuit group are three second detection circuit groups each consisting of two detection circuits. The computing unit calculates an angle value for each of all the second detection circuit groups on the basis of the output signals of the two detection circuits, extracts one or more normal first detection circuit groups each of which is such one that all three angle values corresponding to the three second detection circuit groups fall within an angle range of a predetermined breadth, and determines an angle detection value on the basis of at least one of all angle values corresponding to all second detection circuit groups belonging to the one or more normal first detection circuit groups.

Growing community of inventors

Tokyo, Japan

Yohei Hirota