Tdk Corporation

Yuichiro Yamaji

Tamon Kasajima

Taiju Akushichi

Takato Fukui

Makoto Kameno

Osamu Harakawa

Hiraku Hirabayashi

Tsuyoshi Umehara

Shinichirou Mochizuki

Hiroshi Naganuma

A magnetic sensor includes a sensor chip mounted on a substrate such that an element formation surface thereof is perpendicular to the surface of the substrate and a magnetism collecting member mounted on the substrate such that a surface thereof faces the element formation surface. The magnetism collecting member has a surface positioned on the side opposite to the surface, and both the surfaces are flattened. This reduces a gap between the element formation surface and the magnetism collecting member and reduces variations among products. In addition, since the surface is also flattened, the magnetism collecting member has no directionality with respect to the sensor chip when it is mounted on the substrate, so that working efficiency during assembly can be improved.

Magnetic sensor and its manufacturing method

A magnetic sensor includes a sensor chip mounted on a substrate such that an element formation surface thereof is perpendicular to the substrate and a magnetism collecting member mounted on the substrate such that a surface thereof faces the substrate and a surface thereof faces the element formation surface. The arithmetic mean waviness Wa of the surface of the magnetism collecting member is 0.1 μm or less. When the arithmetic mean waviness Wa of the surface of the magnetism collecting member that faces the element formation surface is set to 0.1 μm or less, it is possible to significantly suppress a deterioration in detection sensitivity due to the presence of a gap between the element formation surface and the magnetism collecting member and to significantly reduce variations in detection sensitivity among products.

To facilitate a change in the number and layout of magnetic field detection devices to be arranged in an array. A magnetic field detection device includes a cancel coil wound around a bobbin, a cover member fixed to the bobbin and covering the cancel coil in a direction perpendicular to the axial direction of the cancel coil, and magnetic sensors fixed to the bobbin or cover member. The cover member has side surfaces and extending in the z-direction and positioned on mutually opposite sides. The side surfaces have first and second engagement portions, respectively, and the first engagement portion has a shape engageable with the shape of the second engagement portion. This makes it possible to arrange a desired number of the magnetic field detection devices.

Magnetic field detection device and magnetic field detection device array

To reduce the number of components and simplify the circuit configuration in a magnetic field detection device capable of detecting a weak magnetic field without using a shield room. A magnetic field detection device includes a cancel coil wound around a winding core part of a bobbin, magnetic sensors fixed to mutually different positions of the bobbin, and a feedback circuit that makes a cancel current flow in the cancel coil according to an output signal from the magnetic sensor to cancel the environmental magnetic field in a cancel space. Since the cancel coil is used in common for the magnetic sensors, it is possible to reduce the number of components to be used and to simplify the circuit configuration.

Disclosed herein is a magnetic sensor that includes a first magnetic field sensor that detects an environmental magnetic field to generate a first magnetic field signal, a second magnetic field sensor that detects a detection target magnetic field to generate a second magnetic field signal, a first filter that removes an AC component in a predetermined frequency band from the first magnetic field signal to extract a DC component, a first compensation coil that applies a first cancelling magnetic field to the second magnetic field sensor based on the DC component, a second compensation coil that applies a second cancelling magnetic field to the second magnetic field sensor based on the second magnetic field signal, and a second filter that removes an AC component in at least a predetermined frequency band from the second magnetic field signal.

Magnetic sensor

A correction apparatus for an angle sensor includes a correction information generator for generating correction information, and a correction processing unit for performing correction processing in the course of generation of a detected angle value by an angle detector. Details of the correction processing are determined on the basis of the correction information. The correction information generator includes an error estimate generation unit and a correction information determination unit. The error estimate generation unit generates, on the basis of a first signal and a second signal, an error estimate containing a variable component that varies depending on an ideal angle estimate. The correction information determination unit determines the correction information on the basis of the error estimate.

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Tokyo, Japan

Yuichiro Yamaji