JP3311614B2 - Magnetic detection device and magnetoresistive element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a high-sensitivity magnetic detection device and a magnetoresistive element for detecting movement, rotation, and the like of an object to be detected by utilizing a resistance change of the magnetoresistive element.

[0002]

2. Description of the Related Art A magnetic sensor has a bias magnet and detects movement, rotation, and the like of a detection target made of a magnetic material by using a resistance change of a magnetoresistive effect element. , Widely used.

As a known technique of this type of conventional magnetic sensor, there is, for example, one disclosed in Japanese Patent Application Laid-Open No. 3-195970. FIG. 11 shows a method of the magnetic sensor described in JP-A-3-195970. The magnetic sensor shown in FIG. 11 is provided with a bias magnet 15 that generates a bias magnetic field 13 toward the gear 11 as a detection target made of a magnetic material.

An insulating substrate 1 having magnetoresistive elements 16a and 16b formed on a surface perpendicular to the direction of the bias magnetic field 13
7a is arranged. The lines of magnetic force of the bias magnetic field generated from the bias magnet 15 are periodically modulated at the peaks and valleys of the gear 11 and change sinusoidally according to the relative positions of the teeth of the gear 11.

The deflection angle θ of the bias magnetic field 13
It changes with the movement of 1. The change in the magnetic field strength in the deflection angle direction generated in the plane of the magnetoresistive element 16b due to the change in the magnetic field angle is detected as a change in the resistance of the magnetoresistive element 16b, and the movement of the gear 11 is detected.

However, in the configuration of the conventional magnetic sensor, the gear 11 and the magnetoresistive elements 16a, 16b
As the air gap between them increases, the deflection angle sharply decreases, and the sensitivity decreases.

The present applicant has filed an unexamined Japanese Patent Application No. 8-172499 for a magnetic detection device in order to improve the sensitivity. This unknown magnetic detection device is shown in FIG.
It is shown in FIG.

In FIG. 12, a first magnet 25a and a second magnet 25b generate a bias magnetic field toward the gear 11. The second magnet 25b is arranged to face the first magnet 25a with opposite poles, and is arranged in the movement direction of the gear 11.

The magnetoresistive element 16 includes a first magnet 25
a, which is located in a plane substantially perpendicular to the direction of movement of the gear 11 in a bias magnetic field between the second magnet 25a and the second magnet 25b.

As shown in FIG. 13, the magneto-resistance effect element 16 is provided with a magneto-resistance effect element 16a.
b are connected in series. The magnetoresistive element 16a is arranged in a direction perpendicular to the direction X toward the gear 11, and the magnetoresistive element 16b is arranged in a direction X toward the gear 11.

According to such a magnetic detecting device, FIG.
As shown in (2), in the space between the first magnet 25a and the second magnet 25b, a bias magnetic field is generated in the movement direction of the gear 11. The bias magnetic field in the movement direction of the gear 11 is
Due to the movement of the gear 11, the vibration is modulated by a deflection angle θ in the direction X toward the gear 11.

For this reason, the magnetoresistive element 16a arranged in a direction perpendicular to the direction X toward the gear 11
A change in resistance is caused by a change in the state of the bias magnetic field according to the movement of No. 1. Therefore, the gear 11 and the magnetoresistive element 16
The reduction in the amount of magnetic field modulation with respect to the air gap with a is relatively small, and the sensitivity to the air gap can be improved.

Incidentally, a magnetoresistive element (MRE) 1
6a, as shown in FIG. 13, MRE1, MRE2, MRE
RE3... MREn are connected in series. The magnetic field detected by the magnetoresistive element 16a is in the direction X toward the gear 11.
The magnetic field H of FIG.

[0014]

However, the intensity of the magnetic field H depends strongly on the position in the direction X. For this reason,
When the magnetoresistive element 16 is arranged in the bias magnetic field,
In the same magnetoresistive element 16a, a difference occurs in the magnetic operating point depending on the location. FIG. 15 shows the magnetoresistive element 16a.
As shown in the figure, the resistance changes depending on the magnetic field strength.

The movement of the gear 11 causes the magnetic field to change within a predetermined range around the operating point, so that the resistance value changes accordingly. For example, M on the side close to the gear 11
RE1, MREA at point A, M on the far side from gear 11
The respective operating points of REn are as shown in FIG.

The change in the resistance value with respect to the change in the magnetic field intensity having the same amplitude is as shown in FIG. 16 because MRE1 is the smallest, MREA is medium, and MREn is the largest. The resistance change of the magnetoresistive element 16a is MRE.
1 to MREn, and has a waveform as shown in FIG. This waveform is distorted, causing a problem that a stable sensor output cannot be obtained.

In this case, if the dimension of the sensor in the X direction is larger than the bias magnetic field dH / dX, the above-described problem occurs. The bias magnetic field dH / dX is determined by the shape of the magnet, and can be reduced by lengthening the magnet in the X direction. However, the size of the magnet cannot be reduced because the magnet is large. For this reason, there has been a demand for a magnetic detection device that can obtain a stable sensor output without waveform distortion.

An object of the present invention is to provide a magnetic detector and a magnetoresistive element which can obtain a stable sensor output without waveform distortion.

[0019]

The present invention employs the following means in order to solve the above-mentioned problems. The invention according to claim 1 is a first magnet that generates a magnetic field toward a detection target having a magnetic material, and a first magnet that generates a magnetic field toward the detection target and opposes different poles to each other. A second magnet, which is disposed to face and is arranged in the direction of movement of the object to be detected, and in a magnetic field between the first magnet and the second magnet, which is substantially perpendicular to the direction of movement of the object to be detected. First magnetoresistive means arranged on the surface and generating a resistance change by a change in a magnetic field according to the movement of the detection target, wherein the first magnetoresistance means is substantially arranged in a direction toward the detection target. A plurality of micro-magnetoresistive means consisting of patterns arranged in a vertical direction are arranged in parallel along the direction toward the detection target and connected in series,
The gist is that the width size of the plurality of micro magnetoresistive means in the direction toward the detection target is shorter than the pattern size of each micro magnetoresistive means in the substantially perpendicular direction by a predetermined size.

According to the present invention, in the space between the first magnet and the second magnet, a bias magnetic field is generated in the movement direction of the detection target, and the bias magnetic field in the movement direction of the detection target is The modulation is performed in the direction toward the detection target. In this case, since each micro-magnetic resistance means is a pattern arranged in a direction substantially perpendicular to the direction toward the detection target,
A resistance change is caused by a change in the state of the bias magnetic field according to the movement of the detection target.

The width of the plurality of micro-magnetoresistive means in the direction toward the detection target is shorter than the pattern size of each micro-magnetoresistor in the vertical direction by a predetermined size. Since the distance between them becomes even shorter, the difference between the respective magnetic resistances and the respective resistance values of the respective micro-magnetic resistance means is small.

That is, since the difference between the operating points of the micro-magnetoresistive means can be reduced, the resistance change between the micro-magnetoresistive means also has a small difference, and has a sinusoidal waveform having substantially the same waveform and no waveform distortion. . Therefore, the waveform of the combined resistance value obtained by combining the waveforms of the respective resistance values of the respective micro-magnetic resistance means is a sine waveform without waveform distortion, so that a stable sensor output without waveform distortion can be obtained.

According to a second aspect of the present invention, there is provided a second magnetoresistive means connected in series with the first magnetoresistive means and arranged in the substantially vertical direction. The gist of the present invention is that a plurality of micro-magnetoresistive means each having a pattern of the above-mentioned width and arranged in the direction toward the object to be detected are juxtaposed in a substantially perpendicular direction.

According to the present invention, the second magnetoresistive means comprises a plurality of micro magnetoresistive means formed of short patterns arranged in the direction toward the object to be detected, arranged in parallel along the substantially vertical direction. Therefore, the change in resistance according to the change in the magnetic field is very small compared to the change in resistance of the first magnetoresistive means, and has a substantially constant resistance value, and the first magnetoresistive means and the second magnetoresistive means An output signal corresponding to a change in resistance of the first magnetoresistive means can be obtained from the midpoint terminal.

In the third aspect of the present invention, the first magnetic resistance means and the second magnetic resistance means are arranged near the magnetic pole surface of the first magnet or the second magnet on the side to be detected. The point is that

According to the present invention, since the magnitude of the modulation of the bias magnetic field becomes maximum near the magnetic pole surface of the first magnet or the second magnet on the side of the detection target, the first magnet is located at this position. By arranging the magnetoresistive means and the second magnetoresistive means, a large resistance change can be obtained.

A third aspect of the present invention is a third magnetoresistive means connected to the second magnetoresistive means and arranged in the substantially vertical direction and having the same configuration as the first magnetoresistive means. A fourth magnetoresistive means connected to the third magnetoresistive means and the first magnetoresistive means and arranged in the substantially vertical direction and having the same configuration as the second magnetoresistive means. Is the gist.

According to the present invention, the first through fourth magnetoresistive means are arranged along the substantially perpendicular direction, so that the first through fourth magnetoresistive means are provided. The size in the direction toward the detection target becomes relatively small. Therefore, the phase difference between the respective midpoint potentials of the respective magnetoresistive means becomes 180 °, and the midpoint potential difference becomes a high sensor output.

According to a fifth aspect of the present invention, the first to fourth magnetoresistive means are arranged near a magnetic pole surface of the first magnet or the second magnet on the side to be detected. The point is that

According to a sixth aspect of the present invention, a first magnetic resistance means 18a for detecting a magnetic field generated by a magnet and generating a resistance change by a change in the magnetic field in accordance with the movement of the object to be detected;
And a second magnetoresistive means 18b connected in series to the magnetoresistive means, wherein the first magnetoresistive means comprises a micromagnetic resistance means having a pattern arranged in a predetermined direction, the micromagnetic resistance means being perpendicular to the predetermined direction. A plurality of micro-magnetoresistive means are connected in series by arranging a plurality of micro-magnetoresistive means so that the vertical width of the plurality of micro-magnetoresistors is shorter than the pattern size of the respective micro-magnetoresistors by a predetermined size. The gist of the present invention is that the second magnetoresistive means is formed by arranging a plurality of micro magnetoresistive means having a pattern of the width substantially arranged in the vertical direction, along the predetermined direction.

[0031]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a magnetic detecting device according to an embodiment of the present invention. FIG. 1 shows a perspective view of Embodiment 1 of the magnetic detection device of the present invention.

<Embodiment 1> The magnetic detection device shown in FIG. 1 is a magnetic sensor, and has a gear 11 as an object to be detected which performs a rotational movement.

On the right side of the gear 11, an insulating substrate 20 having a first bias magnet 25a, a second bias magnet 25b, and a magnetoresistive element 18 is provided.

The insulating substrate 20 has an integrated circuit (IC)
19, a plurality of electronic components such as a resistor and a capacitor 21 are mounted. That is, the first bias magnet 25a
Since the insulating substrate 20 having the magnetoresistive element 18 can be inserted between the second bias magnet 25b and the second bias magnet 25b, a plurality of electronic components can be mounted on the insulating substrate 20.

The first bias magnet 25a generates a bias magnetic field toward the gear 11 having a magnetic material, and has an N pole on the gear 11 side.

The second bias magnet 25b is arranged in the movement direction of the gear 11 so as to face the first bias magnet 25a, and generates a bias magnetic field toward the gear 11 having the magnetic material. An S pole is arranged on the side.

The magnetoresistive effect element 18 comprises a magnetoresistive effect element 18a and a magnetoresistive effect element 18b, and is provided in a bias magnetic field between the first bias magnet 25a and the second bias magnet 25b. It is installed on a plane perpendicular to the direction of movement of the gear 11 and generates a resistance change due to a state change of the bias magnetic field according to the movement of the gear 11.

FIG. 2 shows the structure of the magnetoresistive element 18. The magnetoresistive element 18 is a magnetoresistive element 18.
a is connected to a magnetoresistive element 18b. The magnetoresistive effect element 18a includes MRE1 and MR as micro magnetoresistive means composed of three patterns which are elongated in the vertical direction (the direction perpendicular to the direction X toward the gear 11).
E2 and MRE3 are connected in series and have a terminal a to which power is supplied. The distance in the X direction from MRE1 to MRE3 is sufficiently small. The size of the pattern of the magnetoresistive element 18a is, for example, several times to several tens times the size in the X direction from MRE1 to MRE3.

The magnetoresistive element 18b has an MR pattern having a short length in the horizontal direction (direction X toward the gear 11).
About 10 to 20 Es are arranged, each MRE is connected in series, and has a ground terminal c. The sensor output is obtained from the midpoint terminal b. The size of the short-length pattern is slightly larger than the size in the X direction from MRE1 to MRE3.

The magnetoresistive element 18a is arranged in a direction perpendicular to the direction X toward the gear 11, and the magnetoresistive element 18b is arranged in the direction X toward the gear 11.

The resistance of the magnetoresistive elements 18a and 18b changes depending on the angle between the direction of the current flowing through the magnetoresistive elements and the direction of the magnetic field, and the magnetic field strength.

The angle between the direction of the current and the direction of the magnetic field is 90.
゜, that is, the magnetoresistive element 18a
The resistance changes depending on the magnitude of the magnetic field strength in the direction X toward the gear 11.

When the angle between the direction of the current and the direction of the magnetic field is 0 °, that is, the resistance of the magnetoresistive element 18b does not change regardless of the magnitude of the magnetic field strength. Here, since the resistance of only the magnetoresistive element 18a changes, its output is used.

The magnetoresistive elements 18a and 18b are arranged near the magnetic pole surface of the bias magnet 25a on the gear 11 side and at a position offset from the center between the magnets.

According to the magnetic detecting device configured as described above, the bias magnetic field between the first bias magnet 25a and the second bias magnet 25b determines the direction of movement of the gear 11,
That is, the direction is from the N pole of the first bias magnet 25a to the S pole of the second bias magnet 25b.

The bias magnetic field oscillates in the direction X toward the gear 11 due to the movement of the gear 11. That is,
As the gear 11 moves, the bias magnetic field component in the direction X toward the gear 11 changes.

MRE1-MR of magnetoresistive element 18a
E3 is a surface substantially perpendicular to the movement direction of the gear 11 (that is, a surface parallel to the magnet surfaces of both magnets 25a and 25b), and is arranged in a direction perpendicular to the direction X toward the gear 11. I have. That is, since the angle between the direction of the current and the direction of the magnetic field is approximately 90 °, the magnetoresistance effect element 18a
Is a direction X toward the gear 11 according to the movement of the gear 11.
The resistance changes due to the change in the magnetic field strength of

The MRE1 of the magnetoresistive element 18a
To MRE3 are composed of elongated patterns,
Since the distance in the X direction from RE1 to MRE3 is sufficiently small, the difference between the resistance values of MRE1, MRE2, and MRE3 with respect to the magnetic field strength is small, as shown in FIG.

That is, the difference between the operating points in the magnetoresistive element 18a can be reduced. Therefore, MRE
When the magnetic field changes within a predetermined range around each operating point of MRE1, MRE2, and MRE3, the resistance change with respect to time at that time also changes as shown in FIG.
The difference between the MREs 3 is small, and the sine waveform has almost the same waveform and no waveform distortion.

The waveform of the combined resistance value obtained by combining the waveforms of the respective resistance values of MRE1, MRE2, and MRE3 is a sine waveform having no waveform distortion as shown in FIG. This combined resistance value is the resistance value of the magnetoresistive element 18a, and a sensor output is obtained by a change in the resistance value, so that a stable sensor output without waveform distortion can be obtained.

Since the fluctuation of the bias magnetic field in the direction perpendicular to the direction X toward the gear 11 is small, the effect of lengthening the pattern in this direction is small.

Further, since the magnetoresistive effect element 18a is arranged on the side of the gear 11 shifted from the center between the first bias magnet 25a and the second bias magnet 25b, the bias magnetic field swings greatly. , The change in resistance increases, and a higher sensor output can be obtained.

Further, when the magnetoresistive effect element 18a is arranged on the magnetic pole surface side of the first bias magnet 25a or the magnetic pole surface side of the second bias magnet 25b, the bias magnetic field swings more, so that the resistance change occurs. And a higher sensor output can be obtained.

In the first embodiment, the magneto-resistance effect element 18 is constituted by the magneto-resistance effect element 18a and the magneto-resistance effect element 18b.
Only a may be used. That is, the resistance change with respect to the magnetic field change according to the movement of the gear 11 is
This is because it is determined only by a.

Although the angle between the pattern of the magnetoresistive element 18a and the direction X toward the gear 11 is 90 °,
The angle may be around 90 °, for example 80 °.

<Second Embodiment> Next, a second embodiment of the magnetic detection device of the present invention will be described. In the first embodiment, the half-bridge type magnetoresistive element 18 including the vertical magnetoresistive element 18a and the horizontal magnetoresistive element 18b is used.

In the second embodiment, a full-bridge type magneto-resistance effect element using two half-bridge type magneto-resistance effect elements 18 will be described. First, FIG. 6 shows a configuration of a conventional full-bridge type magnetoresistance effect element.

In the full-bridge type magnetoresistive element shown in FIG. 6, one end of a magnetoresistive element 16a1 composed of a vertical pattern and one end of a magnetoresistive element 16b1 composed of a horizontal pattern arranged in the Y direction. Connected to terminal a. The other end of the magnetoresistive element 16b1 and a magnetoresistive element 1 composed of a vertical pattern arranged in the X direction
One end of 6a2 is connected to the midpoint terminal d.

The other end of the magnetoresistive element 16a2 and the magnetoresistive element 1 formed of a horizontal pattern arranged in the Y direction
One end of 6b2 is connected to the midpoint terminal b. The other end of the magnetoresistive element 16b2 and the other end of the magnetoresistive element 16a1 are connected to the midpoint terminal c.

When the midpoint potential Va is extracted from the midpoint terminal a of such a full bridge magnetoresistive element and the midpoint potential Vb is extracted from the midpoint terminal b, the result is as shown in FIG.

In such a full-bridge magnetoresistive element, since the four magnetoresistive elements 16a1 to 16a2 are arranged in a considerably long size in the X direction, in addition to the above-mentioned problem of waveform distortion of the sensor output, The phase difference of the midpoint potential of each midpoint terminal deviates from 180 °.

Therefore, in the second embodiment, in order to make the phase difference of the midpoint potential of each midpoint terminal 180 °, a full bridge type magnetoresistive element shown in FIG. 8 is used. In the full bridge type magnetoresistive element shown in FIG. 8, one end of a magnetoresistive element 18a1 having a vertical pattern and a magnetoresistive element 1 having a horizontal pattern arranged in the Y direction.
One end of 8b1 is connected to the midpoint terminal a.

The other end of the magnetoresistive element 18b1 and the magnetoresistive element 1 composed of a vertical pattern arranged in the Y direction
One end of 8a2 is connected to the midpoint terminal d. The other end of the magnetoresistive element 18a2 and one end of a magnetoresistive element 18b2 formed of a horizontal pattern arranged in the Y direction are connected to the midpoint terminal b. The other end of the magnetoresistive element 18b2 and the other end of the magnetoresistive element 18a1 are connected to the midpoint terminal c.

The magneto-resistance effect elements 18a1 and 18a2
It has the same configuration as the magnetoresistive element 18a shown in FIG. 2, and the magnetoresistive elements 18b1 and 18b2 have the same configuration as the magnetoresistive element 18b shown in FIG.

The four magnetoresistive elements 18a1, 18a1,
18a2, 18b1, and 18b2 are arranged near the magnetic pole surface of the first magnet 25a or the second magnet 25b on the gear 11 side.

When the midpoint potential Va is extracted from the midpoint terminal a of such a full-bridge magnetoresistive element, and the midpoint potential Vb is extracted from the midpoint terminal b, a waveform as shown in FIG. 9 is obtained.

That is, in the full-bridge magnetoresistive element shown in FIG.
Since 18b2 is arranged in a short long size in the X direction,
The waveform distortion of the sensor output can be eliminated, and the phase difference of the midpoint potential of each midpoint terminal is 180 °.

FIG. 10 shows a change with time of the midpoint potential difference obtained by subtracting the midpoint potential Vb of the midpoint terminal b from the midpoint potential Va of the midpoint terminal a. In the conventional example, as shown in FIG. 7, the phase difference between the midpoint potential Va and the midpoint potential Vb is 18
Since it deviates from 0 °, the midpoint potential difference is relatively small as shown in FIG. For this reason, the sensor output was small.

On the other hand, in the present invention, as shown in FIG. 9, since the phase difference between the midpoint potentials Va and Vb is 180 °, the midpoint potential difference is relatively large as shown in FIG. . Therefore, if the magnetoresistance effect element shown in FIG. 8 is used,
There is no waveform distortion, and a high sensor output can be obtained.

The full-bridge type magnetoresistive element may be mounted on the insulating substrate 20, and the IC 19, the resistor and the capacitor 21 described in the first embodiment may be mounted on the insulating substrate 20.

[0071]

According to the present invention, in the space between the first magnet and the second magnet, a bias magnetic field is generated in the motion direction of the detection target, and the bias magnetic field is generated in the motion direction of the detection target. Is modulated in a direction toward the detection target. In this case, since each micro-magnetic resistance means is a pattern arranged in a direction substantially perpendicular to the direction toward the detection target,
A resistance change is caused by a change in the state of the bias magnetic field according to the movement of the detection target.

The width of the plurality of micro-magnetoresistive means in the direction toward the detection target is shorter than the pattern size of each micro-magnetoresistor in the vertical direction by a predetermined size. Since the distance between them becomes even shorter, the difference between the respective magnetic resistances and the respective resistance values of the respective micro-magnetic resistance means is small.

That is, since the difference between the operating points of the micro-magnetoresistive means can be made small, the resistance change between the micro-magnetoresistive means also has a small difference, and has a sine waveform having substantially the same waveform and no waveform distortion. . Therefore, the waveform of the combined resistance value obtained by combining the waveforms of the respective resistance values of the respective micro-magnetic resistance means is a sine waveform without waveform distortion, so that a stable sensor output without waveform distortion can be obtained.

The second magnetoresistive means is composed of a plurality of micro magnetoresistive means formed of short patterns arranged in the direction toward the object to be detected and arranged in parallel along the substantially perpendicular direction. Is very small compared to the resistance change of the first magnetoresistive means and has a substantially constant resistance value, and the midpoint between the first magnetoresistive means and the second magnetoresistive means. From the terminal, an output signal corresponding to the resistance change of the first magnetic resistance means can be obtained.

Further, since the magnitude of the modulation of the bias magnetic field is maximum near the magnetic pole surface of the first magnet or the second magnet on the side to be detected, the first magnetic resistance means and the By arranging the second magnetic resistance means, a large resistance change can be obtained.

Further, if the first to fourth magnetoresistive means are arranged along the substantially vertical direction, the first to fourth magnetoresistive means can be detected by the first to fourth magnetoresistive means. The size in the direction to go is relatively small. For this reason,
Since the phase difference between the respective midpoint potentials of the respective magnetic resistance means is 180 °, the midpoint potential difference becomes a high sensor output.

[Brief description of the drawings]

FIG. 1 is a perspective view of a magnetic detection device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram illustrating a magnetoresistance effect element according to the first embodiment.

FIG. 3 is a diagram showing magnetic operating points of MRE1 to MRE3.

FIG. 4 is a diagram illustrating a change in resistance value of each of MRE1 to MRE3.

FIG. 5 is a diagram showing a change in a combined resistance value of MRE1 to MRE3.

FIG. 6 is a configuration diagram showing a conventional full-bridge type magnetoresistive element.

FIG. 7 is a diagram showing a waveform of a midpoint potential at a midpoint terminal of a conventional full-bridge type magnetoresistive element.

FIG. 8 is a configuration diagram illustrating a full-bridge type magnetoresistance effect element according to a second embodiment.

FIG. 9 is a diagram showing a waveform of a midpoint potential at a midpoint terminal of the full-bridge type magnetoresistance effect element according to the second embodiment.

10 is a diagram showing a comparison between a midpoint potential difference of a conventional full-bridge type magnetoresistance effect element and a midpoint potential difference of the full-bridge type magnetoresistance effect element of the second embodiment. FIG.

FIG. 11 is a perspective view of an example of a conventional magnetic detection device.

FIG. 12 is a perspective view of another magnetic detection device.

FIG. 13 is a configuration diagram showing a magnetoresistive element used in the another magnetic detection device.

FIG. 14 is a diagram showing a deflection angle of a magnetic field of the other magnetic detection device.

15 is a diagram showing a magnetic operating point of each MRE of the magnetoresistance effect element shown in FIG.

16 is a diagram showing a change in each resistance value corresponding to each MRE shown in FIG.

17 is a diagram illustrating a change in a combined resistance value obtained by combining the resistance values corresponding to the respective MREs illustrated in FIG. 13;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Gear 13 Magnetic field direction 15 Bias magnet 16a, 16b, 18a, 18b Magnetoresistance effect element 19 IC 17a, 20 Insulating substrate 21 Resistance / capacitor 25a First bias magnet 25b Second bias magnet

Continuation of the front page (58) Fields investigated (Int.Cl. ⁷ , DB name) G01D 5/00-5/62 G01B 7/00-7/34 H01L 43/08 G01R 33/09 G01P 1/00-3 / 80

Claims (6)

(57) [Claims] 1. A first magnet that generates a magnetic field toward a detection target having a magnetic material, and a first magnet that generates a magnetic field toward the detection target and opposes the different poles to face the first magnet. And a second magnet disposed in the movement direction of the detection target, and a surface substantially in a magnetic field between the first magnet and the second magnet and substantially perpendicular to the movement direction of the detection target. And first magnetic resistance means for generating a resistance change by a change in a magnetic field according to the movement of the detection target, wherein the first magnetic resistance means is substantially perpendicular to a direction toward the detection target. A plurality of micro-magnetoresistive means consisting of patterns arranged in different directions are arranged in parallel along the direction toward the object to be detected and connected in series, and the width of the plurality of micro-magnetic resistance means in the direction toward the object to be detected The pattern in the substantially vertical direction of each micro-magnetoresistive means Magnetic detection device, characterized in that the predetermined size has been smaller than size. And a second magnetoresistive means connected in series with the first magnetoresistive means and arranged in the substantially vertical direction, wherein the second magnetoresistive means is connected to a detection target. 2. The magnetic detecting device according to claim 1, wherein a plurality of micro-magnetic resistance means having a pattern of the width substantially arranged in a direction toward the head are arranged in parallel along the substantially vertical direction. 3. The method according to claim 1, wherein the first and second magnetoresistive means are arranged near a magnetic pole surface of the first magnet or the second magnet on the detection target side. 3. The magnetic detection device according to claim 2, wherein: 4. A third magnetoresistive means connected to the second magnetoresistive means and arranged in the substantially vertical direction and having the same configuration as the first magnetoresistive means, and the third magnetic means. A fourth magnetic resistance means connected to the resistance means and the first magnetic resistance means and arranged in the substantially vertical direction and having the same configuration as the second magnetic resistance means. Item 3. The magnetic detection device according to Item 2. 5. The apparatus according to claim 1, wherein the first to fourth magnetoresistive means are arranged near a magnetic pole surface of the first magnet or the second magnet on the detection target side. The magnetic detection device according to claim 4, wherein 6. A first magnetic resistance means for detecting a magnetic field generated by a magnet and causing a change in resistance by a change in a magnetic field in accordance with the movement of a detection target, and connected in series to the first magnetic resistance means. A second magnetoresistive means, wherein the first magnetoresistive means comprises a plurality of micro magnetoresistive means formed of a pattern arranged in a predetermined direction, arranged in parallel along a direction perpendicular to the predetermined direction. Connected in series, the width of the plurality of micro-magnetoresistive units in the vertical direction is made smaller by a predetermined size than the pattern size of each micro-magnetoresistor in the predetermined direction; A magnetoresistive element, wherein a plurality of micro magnetoresistive means each having a pattern of substantially the same width and arranged in the vertical direction are arranged in parallel along the predetermined direction.