JP2001356154A - Magnetometric sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify the structure of a three-axis magnetometric sensor using high-frequency carrier type magnetometric sensor elements or the like as elements. SOLUTION: The angles of the detection shafts of three magnetometric sensor elements against a fitting base face are set to about 35 deg., the magnetometric sensor elements are arranged so that the projections of the detection shafts of the magnetometric sensor elements against a fitting base have angles of 120 deg., thereby the detection shafts of the magnetometric sensor elements are made orthogonal to each other. The magnetic bias direction is made perpendicular to the fitting base face so that the same magnetic bias is applied to the magnetometric sensor elements to form this three-axis magnetometric sensor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic sensor for detecting a magnetic field at a terrestrial magnetic field with high sensitivity and high accuracy, and more particularly to a magnetic sensor using a high-frequency carrier type magnetic sensor utilizing a change in impedance of a magnetic field.

[0002]

2. Description of the Related Art Conventionally, when three-axis magnetism is detected using this type of high-frequency carrier type magnetic sensor, a magnetic sensor element consisting of a magnetic core wound with a magnetic bias coil is mounted on each of the three axes. It was arranged in the direction to perform magnetic detection. For this reason, it is necessary to apply a winding to each magnetic sensor element individually, and the manufacturing process has been complicated. In addition, since a magnetic sensor having different specifications is manufactured for each detection axis, management of the manufacturing process is complicated.

[0003]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to use a high-frequency carrier type magnetic sensor as an element.
An object of the present invention is to simplify the structure of a shaft magnetic sensor. Another object of the present invention is to streamline the manufacturing process and management of the magnetic sensor.

[0004]

In order to solve the above-mentioned problems, the present invention reduces the number of magnetic bias coils and reduces the size of the entire magnetic sensor by studying the arrangement of the magnetic sensor element and the magnetic bias coil. It is intended.

That is, according to the present invention, in a magnetic sensor in which three magnetic sensor elements are arranged on a mounting substrate, the detection axes of the respective magnetic sensor elements make an angle of about 35 ° with respect to the mounting substrate surface, and Wherein the projections of the detection axes of the magnetic sensor elements onto the mounting substrate are arranged at an angle of about 120 ° to each other, and the detection axes of the respective magnetic sensor elements are substantially orthogonal to each other. .

According to the present invention, there is provided the magnetic sensor described above, wherein a magnetic bias is applied in a direction perpendicular to the mounting substrate.

Further, the present invention is the above-mentioned magnetic sensor, wherein the magnetic sensor element is a high-frequency carrier type magnetic sensor utilizing an impedance variation caused by a variation of a skin effect when a high-frequency voltage is applied to a magnetic body. A magnetic sensor characterized in that:

The present invention also provides a thin-film high-frequency carrier-type magnetic sensor having a detection axis formed on a surface of a rectangular dielectric substrate at an angle of about 35 ° with one side of the dielectric substrate,
A magnetic sensor, wherein an electrode for impedance detection is arranged near the one side of the dielectric substrate, and the one side of the dielectric substrate is attached so as to be parallel to the surface of the mounting substrate. is there.

[0009]

The magnetic sensor according to the present invention has the above-described configuration, so that the required number of coils for applying a magnetic bias is basically one. Since the same specifications can be obtained, the manufacturing process can be greatly simplified. In addition, the reduction in the number of parts enables a reduction in manufacturing cost due to a synergistic effect with simplification of the manufacturing process.

Here, the configuration of the present invention will be described.
FIG. 5 shows the direction of the magnetic bias and the direction of the detection axis of the magnetic sensor element in the magnetic sensor of the present invention. In the conventional three-axis magnetic sensor, a magnetic bias is separately applied to the magnetic sensor elements for detecting the respective axis components. However, as shown in FIG. When S ₁ , S ₂ , and S ₃ are represented by (1, 0, 0), (0, 1, 0), and (0, 0, 1) as vector components, respectively, (1, 1, 1) When a magnetic bias _Hb is applied in the direction, a magnetic field bias is evenly applied to each of the magnetic sensor elements.

In FIG. 5, the ratio of the distance between the origin and (1, 0, 0) and the distance between the origin and (1, 1, 1) is 1/3.
^1/2 , a line segment connecting the origin and (1, 0, 0),
(1,0,0) from the line segment perpendicular connecting (1,1,1), the _{H b} and _{S 1} the angle θ, cosθ = 1/3
It is given by ^1/2 . That is, θ becomes about 55 °, and H _b
And the angle of _S 2, _{S 3} is the same.

[0012] Then, the direction of the magnetic bias N _b in FIG. 5, is set to a direction perpendicular to the mounting substrate of the magnetic sensor, the angle of the detection axis of the mounting substrate surface and the magnetic sensor element, 35 ° respectively Become. FIG. 6 schematically shows the state.

FIG. 7 shows the mounting substrate surface 6 in FIG.
1 shows the orientation of the detection axis of each magnetic sensor element when 1 is set on the paper surface and the magnetic bias direction is set on the vertical direction on the paper surface. As shown in this figure, the projections of the respective magnetic sensor elements onto the mounting substrate share the origin and are spaced at 120 ° intervals.

However, in the arrangement shown in FIG. 7, no matter what the configuration of the magnetic sensor element is used, the mounting electrodes and the like are dense and the connection and assembly work becomes difficult. It is also possible to move the detection axis of each magnetic sensor element in parallel. FIG. 8 shows one example of this, in which the projection of each magnetic detection axis onto the mounting board forms a triangle. With such an arrangement, the assembly process of the magnetic sensor can be simplified.

That is, the detection axis of each magnetic sensor element makes an angle of about 35 ° with the substrate surface, and the projection of the detection axis of each magnetic sensor element onto the substrate makes an angle of 120 ° with each other. , It is possible to obtain a magnetic sensor whose structure is simplified as compared with the related art.

[0016]

Next, embodiments of the present invention will be described in detail with reference to specific examples. In this embodiment, an element in which a high-frequency carrier type magnetic sensor is formed as a thin film on the surface of a rectangular dielectric substrate is used as the magnetic sensor element. FIG. 2 is a view schematically showing the magnetic sensor element 20, wherein a magnetic core 22 and a conductor 2 are provided on a dielectric substrate 21.
3 shows a state in which the electrode 24 is provided.

In this figure, the axis of the magnetic core 22 forms an angle of 35 ° with the lower side of the substrate. That is, three magnetic sensor elements are manufactured, and the lower side of the figure is attached to the mounting board so that the angle between the directions of the magnetic sensor elements is 120 °.
It can be used for shaft magnetic sensors.

Specifically, in the present embodiment, the magnetic sensor element 20 of FIG. 2 is configured to be attached to a triangular prism-shaped member. FIG. 3 is a diagram illustrating a state in which the magnetic sensor element 20 is attached to a triangular prism member 31. By attaching a magnetic bias coil so that a magnetic bias is applied to the center axis of the triangular prism, a three-axis magnetic sensor is obtained.

FIG. 4 schematically shows the magnetic bias coil 40 used in the present embodiment. FIG.
Shows a state in which the components shown in FIG. 3 are inserted into the inside of the magnetic bias coil 40 and assembled on a mounting board (not shown);
That is, it is a diagram showing a completed state of the three-axis magnetic sensor according to the present invention.

By adopting such a configuration, the conventional 3
The number of required magnetic bias coils can be reduced to one. In the conventional type, at least two types of specifications of the magnetic sensor element were required for two axes in the plane of the mounting substrate and for the direction perpendicular to the mounting substrate, but they can be unified to one specification.

When it is desired to set the detection axis in the direction perpendicular to the plane of the mounting board, an operation for converting the coordinate axes may be performed. Specifically, two axes in the plane of the mounting board are set to (1, 0,
Assuming that the axis in the direction perpendicular to the mounting board is (0,0,1) as (0), (0,1,0), it is rotated by −55 ° about (1,0,0) and further (0,0). , 0, 1) about the axis.

[0022]

(Equation 1)

Further, the outputs of the magnetic sensors S ₁ , S ₂ , S ₃ are defined as V ₁ , V ₂ , V ₃ , and the outputs after axis conversion are V _x ,
If V _y , V _z , V _x , V _y , V _z are V ₁ , V ₂ ,
With V ₃ is expressed as Equation 2. In order to obtain the axis conversion output, the addition amplification and operation amplification circuit of the operational amplifier may be used.

[0024]

(Equation 2)

[0025]

As described above, according to the present invention, the configuration of a three-axis magnetic sensor using a high-frequency carrier type magnetic sensor or the like as an element can be greatly simplified as compared with the related art. This makes it possible to simplify the manufacturing process and reduce the manufacturing cost.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a magnetic sensor according to the present invention.

FIG. 2 is a schematic diagram of a magnetic sensor element used in the present invention.

FIG. 3 is a diagram showing a state where a magnetic sensor element is attached to a triangular prism-shaped member.

FIG. 4 is a schematic diagram of a magnetic bias coil used in the present invention.

FIG. 5 is a diagram showing a magnetic detection axis and a direction of a magnetic bias.

FIG. 6 is a diagram showing a detection axis, a magnetic bias direction, and an angle formed by a mounting substrate.

FIG. 7 is a diagram illustrating projection of a detection axis when a magnetic bias direction is set perpendicular to the paper surface.

FIG. 8 is a diagram showing an example of the arrangement of magnetic detection axes according to the present invention.

FIG. 9 is a diagram showing a detection axis of a magnetic sensor element and a coordinate system after conversion.

[Explanation of symbols]

 REFERENCE SIGNS LIST 20 magnetic sensor element 21 dielectric substrate 22 magnetic core 23 conductor wire 24 electrode 31 triangular prism member 40 magnetic bias coil 61 mounting substrate

Claims (4)

[Claims] 1. A magnetic sensor having three magnetic sensor elements arranged on a mounting substrate, wherein the detection axis of each magnetic sensor element forms an angle of about 35 ° with respect to the mounting substrate surface, and each magnetic sensor element A magnetic sensor, wherein the projections of the detection axes on the mounting substrate are arranged so as to form an angle of about 120 ° with each other, and the detection axes of the respective magnetic sensor elements are substantially orthogonal to each other. 2. The magnetic sensor according to claim 1, wherein
A magnetic sensor, wherein a magnetic bias is applied in a direction perpendicular to the mounting substrate. 3. The magnetic sensor according to claim 1, wherein the magnetic sensor element utilizes an impedance change caused by a change in a skin effect when a high-frequency voltage is applied to a magnetic body. A magnetic sensor characterized by being a high-frequency carrier type magnetic sensor. 4. A thin-film high-frequency carrier-type magnetic sensor having a detection axis formed on a surface of a rectangular dielectric substrate at an angle of about 35 ° with one side of the dielectric substrate; The electrode for impedance detection is arranged near the side, and is attached so that the one side of the dielectric substrate is parallel to the surface of the mounting substrate. 3. The magnetic sensor according to claim 1.