Asahi Kasei Microdevices Corporation

Asahi Kasei Kabushiki Kaisha

Shigeki Okatake

Takenobu Nakamura

Makoto Kataoka

Seiichi Kato

Yoshitaka Moriyasu

Masashi Yamada

Masanori Masuda

Taisuke Fujita

Hideyuki Tsuji

A magnetic field measuring apparatus is provided including: a magnetic sensor array configured so that a plurality of magnetic sensor cells including a plurality of magnetic sensors each having a magnetoresistive element and magnetic flux concentrators arranged on both ends of the magnetoresistive element are three-dimensionally arranged and capable of detecting a magnetic field in three axial directions; a magnetic field acquiring section configured to acquire measurement data measured by the magnetic sensor array; and a signal space separating section configured to perform signal separation on a spatial distribution of a magnetic field indicated by the measurement data, based on basis vectors calculated from orthonormal functions and a position and magnetic sensitivity of each magnetic sensor of the magnetic sensor array.

Magnetic field measuring apparatus, magnetic field measuring method, and recording medium storing magnetic field measuring program

Provided is a magnetic field measurement device which includes a magnetic sensor array that is composed of a plurality of magnetic sensor cells, each of which has a magnetic sensor and an output unit for outputting an output signal, arranged at lattice points between two curved surfaces, each of which is bent in one direction, so as to be three-dimensionally arranged, and is capable of detecting an input magnetic field in three-axial directions, a measurement data acquisition unit configured to acquire measurement data measured by the magnetic sensor array, and a magnetic field reconstruction unit configured to reconstruct a magnetic field of a component orthogonal to a virtual sensor array plane with respect to one or more positions on the virtual sensor array plane, which is a plane specified in a three-dimensional space, using the measurement data.

Magnetic field measurement device, magnetic field measurement method, and recording medium having magnetic field measurement program recorded thereon

A measurement in a high accuracy is performed when acquiring a tomographic image or the like. Provided is a measuring apparatus, including an electrode unit including a plurality of electrodes in contact with a living body; a magnetic sensor array, including a plurality of magnetic sensor cells, capable of detecting input magnetic fields in three axial directions in a plurality of positions in a three-dimensional space; a current applying section configured to apply a current flowing in the living body by at least one electrode pair of the plurality of electrodes; a measurement data acquiring section configured to acquire measurement data based on the input magnetic field. Which is detected from the living body by the magnetic sensor array during a current flows in the living body; and an estimation section configured to estimate a current flowing in the living body based on the measurement data.

Measuring apparatus, measuring method and recording medium

The present invention relates to a hall electromotive force signal detection circuit and a current sensor thereof each of which is able to achieve excellent wide-band characteristics and fast response as well as high accuracy. A difference calculation circuit samples a component synchronous with a chopper clock generated by a chopper clock generation circuit, out of an output voltage signal of a signal amplifier circuit, at a timing obtained from the chopper clock, so as to detect the component. An integrating circuit integrates an output from the difference calculation circuit in the time domain. An output voltage signal from the integrating circuit is fed back to a signal amplifier circuit via a third transconductance element.

Hall electromotive force signal detection circuit having a difference calculation circuit and current sensor thereof

Provided is a magnetic field measuring apparatus, comprising: a magnetic sensor array including a plurality of magnetic sensor cells, which is capable of detecting an input magnetic field in three axial directions at a plurality of locations in three-dimensional space; a measurement data acquiring section for acquiring measurement data based on the input magnetic field including a to-be-measured magnetic field; and a measurement data computing section for calibrating the measurement data acquired by the measurement data acquiring section; wherein the measurement data computing section comprises: an indicator calculation section for calculating an indicator illustrating calibration accuracy of the measurement data computing section; and a failure determination section for determining a failure based on the indicator calculated by the indicator calculation section; wherein each of the plurality of magnetic sensor cells comprises: a magnetic sensor; and an output section for outputting a output signal.

Magnetic field measuring apparatus

Provided is a magnetic field measuring apparatus for: acquiring the measurement data measured by a magnetic sensor array that is configured by arraying the plurality of magnetic sensor cells to form a surface covering at least a part of a target object to be measured; performing signal separation on a magnetic field spatial distribution indicated by the measurement data based on a position and magnetic sensitivity of each magnetic sensor; generating a calibration magnetic field at a position on a straight line that can be drawn without crossing the plurality of magnetic sensor cells from the measurement space outside the measurement space; and calibrating a sensor error for the magnetic sensor based on a separation error in a case where signal separation has been performed on a spatial distribution of the calibration magnetic field.

Magnetic field measuring apparatus, magnetic field measuring method and recording medium with magnetic field measuring program recorded thereon

A measurement apparatus is provided, which includes a magnetic sensor array formed by three-dimensionally arranging a plurality of magnetic sensor cells each including a magnetic sensor, and capable of detecting an input magnetic field in three axial directions; a measurement data acquiring section that acquires a plurality of measurement values based on the input magnetic field detected by the magnetic sensor array; a magnetic field calculating section that calculates the input magnetic field based on the measurement values; an error calculating section that calculates a detection error of the input magnetic field, based on the plurality of measurement values and a calculation result obtained by calculating the input magnetic field; and a measurement data selecting section that selects a plurality of measurement values to be used for calculating the input magnetic field by the magnetic field calculating section, from among the plurality of measurement values, based on the detection error.

Magnetic field measurement apparatus

A Hall resistance measurement unit measures a Hall resistance value in two or more current directions between a plurality of terminals of the Hall element. A Hall electromotive force measurement unit measures the Hall electromotive force of the Hall element. A temperature measurement unit measures an operating temperature of the Hall element. A compensation signal generation unit compensates the Hall electromotive force on the basis of the Hall resistance value from the Hall resistance measurement unit and a temperature output value from the temperature measurement unit. A compensation coefficient calculation circuit calculates a compensation coefficient on the basis of the Hall resistance value measured by the Hall resistance measurement unit and the temperature output value measured by the temperature measurement unit. The compensation coefficient includes a mechanical stress compensation coefficient and a temperature compensation coefficient.

Hall electromotive force compensation device and hall electromotive force compensation method

A rotation angle measurement apparatus includes: a first Hall element pair for detecting a magnetic component in a first direction; a second Hall element pair for detecting a magnetic component in a second direction different from the first direction; a third Hall element pair for detecting a magnetic component in a third direction different from the first direction and the second direction; and a fourth Hall element pair for detecting a magnetic component in a fourth direction different from the first to third directions. An angle calculation unit calculates a first rotation angle &#x3b8; of a rotating magnet based upon the strengths of the output signals from the first Hall element pair and the second Hall element pair, and calculates a second rotation angle &#x3b8;c of the rotating magnet based upon the strengths of the output signals from the third Hall element pair and the fourth Hall element pair.

Rotation angle measurement apparatus

A Hall electromotive force signal detection circuit combines offset cancellation means by a spinning current method of a Hall element with a continuous-time signal processing circuit. A Hall element includes first to fourth terminals, and generates a Hall electromotive force signal voltage Vhall. Another Hall element generates another Hall electromotive force signal voltage Vhall. A first switching circuit selects a terminal position for applying a drive current from the four terminals of the Hall element. A second switching circuit selects a terminal position for applying a drive current from the four terminals of the another Hall element, which is different from the terminal position selected by the first switching circuit. A chopper clock generation circuit supplies a chopper clock signal &#x3c6;having two different phases to the switching circuit, and also supplies the chopper clock signal &#x3c6;to the first and second switching circuits.

Hall electromotive force signal detection circuit and current sensor thereof

There are provided a current sensor which has a self-diagnosis function and a signal processing circuit. The current sensor is provided with an offset component output circuitwhich extracts an offset component from an output signal of a Hall elementwhich includes a signal component and an offset component, a reference signal generatorwhich outputs a reference signal, and an error signal generation circuitwhich generates an error signal based on an offset component which the offset component output circuitoutputs and a reference signal. The offset component output circuitis provided with a signal amplification circuitwhich amplifies the output of the Hall elementand outputs an output signal and offset component to a low frequency component and the other to a ripple component.

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Tokyo, Japan

Shigeki Okatake