JP3419533B2 - Magnetic scale and magnetic detection device having the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic scale and a magnetic detection device equipped with the magnetic scale, and more particularly to a magnetic scale suitable for detecting displacement such as an encoder and the like, and displacement in a predetermined direction using the magnetic scale. , A magnetic detection device for detecting velocity or angular velocity.

[0002]

2. Description of the Related Art Conventionally, a magnetic scale has been used in a magnetic encoder and the like, and there are two methods for reading the magnetism as follows. A magnetic recording / reproducing head is used to read the change in the current (Biosavart's law) induced by the coil wound around the high-permeability material when the magnetic flux changes to read the magnetic field distribution on the magnetic scale.

A method in which a magnetoresistive effect element or a Hall effect element is used to detect magnetic field strength. Recently, the method is often used for those requiring small size and high resolution. In this method, a predetermined magnetic pole is exposed on a predetermined magnetic pole exposing surface side. For example, a magnetic scale in which only N poles (positive electrodes) are arranged is used, the intensity of the magnetic field generated by the magnetic scale is converted into an electric signal by either the magnetoresistive effect element or the Hall effect element, and this is read.

[0004]

However, in such a conventional magnetic encoder or the like, only the magnetoresistive effect element or the Hall effect element and a predetermined magnetic pole on the magnetic pole exposed surface side facing the magnetoresistive effect element or the Hall effect element are exposed. Since the displacement and the like were detected by the magnetic scale that was taken out, when the magnetoresistive element and the Hall effect element were placed close to the magnetic scale,
There is a problem that the effective noise level becomes high and the S / N ratio is lowered. That is, as shown in FIG. 15A, upward (+ z direction) from points P and R on the magnetic pole.
The magnetization vector appearing in the downward direction becomes downward (-z direction) in the vicinity of the midpoint (O point) between the magnetic poles located at the same height as the magnetic pole surface, and the downward magnetization vector is the magnetoresistive element or the Hall effect. Even when acting on the element, the electric resistance or the generated voltage of the element increases, so that FIG.
A small peak of the read signal waveform shown in (b) occurs. Therefore, the surface of the magnetic scale (magnetic pole exposed surface)
In the vicinity, the positive side magnetization vector to be detected and the negative side magnetization vector opposite thereto are detected equivalently, and the effective noise level increases.

In order to avoid such a problem, conventionally,
The magnetoresistive effect element and the Hall effect element are separated from the magnetic scale to some extent and slid in a region where magnetization in the −z direction does not occur to detect a magnetic field (detection of position, displacement, etc.). Therefore, not only the read signal level and the resolution are lowered, but also it is not possible to meet the demand for a high degree of miniaturization.

In order to improve the resolution, the following can be considered. B) The pitch of the magnetic pattern of the magnetic scale is made fine and the distance between the magnetic scale and the magnetoresistive effect element or the Hall effect element is narrowed. B) Divide the output sine curve by an electronic circuit. Generally, the method of (b) is adopted, but if the electronic circuit becomes complicated and the signal level fluctuates greatly, division becomes difficult.

As described above, in the conventional magnetic encoder and the like, since the magnetization vector between the magnetic poles wraps around in the opposite direction, the magnetic pole interval cannot be narrowed.
No significant improvement in detection accuracy could be expected. Therefore, the present invention provides a magnetic scale capable of effectively removing the wraparound of the magnetization in the direction opposite to the direction on the magnetic poles at the detection height between the magnetic poles and narrowing the arrangement interval with the magnetic field strength detection element. The first purpose is to effectively use S
A second object is to provide various magnetic detection devices having an improved / N ratio.

[0008]

To achieve the above object, the invention according to claims 1 to 3 is provided with a magnetic pattern having a predetermined magnetic field strength distribution consisting of a plurality of magnetic field generating means, and the magnetic field strength on the magnetic pattern side is the magnetic scale changes regularly at a predetermined detection direction of the magnetic field strength detection element, the magnetic field strength detection
Sandwich a non-magnetic material to be placed at a position facing the output element.
Examples detection direction and a set of N and S poles at least two magnetic poles adjacent to each other physician direction substantially perpendicular to exposed on the same side, provided with at least one pair of magnetic poles in a predetermined position in the detection direction Nde It is characterized by that. Such arrangement of magnetic poles can be realized by using, for example, a substantially horseshoe-shaped (for example, U-shaped or U-shaped) magnet, and a magnetic path similar to that of a horseshoe-shaped magnet can be obtained by combining the magnet with a highly permeable material. It can also be realized by configuring.

The at least one set of magnetic poles is, for example, a plurality of sets of magnetic poles arranged in the detection direction, and the polarities of the magnetic poles in the same row among the plurality of sets of magnetic poles are alternately changed. The polarities of the plurality of magnetic poles may be different from each other, or the polarities of the magnetic poles of the same row among the plurality of magnetic poles may be changed in a predetermined order. The placement can be different.

The plurality of sets of magnetic poles or at least two magnetic poles of N-pole and S-pole arranged in the same row include magnetic poles having different lengths in the detection direction, and a table of the magnetic poles is provided. The one in which the projecting surface is located at a different height according to the length of the projecting surface in the detection direction, or
As described above, the exposed surface of the magnetic pole may have a width that is orthogonal to the detected direction changed according to the length of the exposed surface in the detection direction.

According to a sixth aspect of the present invention, a plurality of magnets are arranged in parallel in a direction orthogonal to the detection direction, and the plurality of sets of magnetic poles are arranged in parallel by the facing portions of the plurality of magnets. Can be configured by the number of columns minus 1. Of course, at least two magnetic poles of N pole and S pole arranged in the same row can be formed by the number of rows obtained by subtracting 1 from the parallel number of the plurality of magnets.

Further, the plurality of sets of magnetic poles may be arranged so as to be spaced at a predetermined angular interval in the circumferential direction which is the detection direction. The magnetic detection device according to the invention of claim 8 is any one of the magnetic scales having the above configuration, a light emitting means for outputting an optical signal, and the non-magnetic body on the magnetic pole surface of the magnetic scale.
And a polarization rotation means for rotating the polarization direction of the optical signal according to the strength of the magnetic field formed by the magnetic poles of the N-pole and the S-pole of each set, and transmitting only the polarized light of a specific direction. Polarization control means, photoelectric conversion means for converting a light intensity signal after passing through the polarization control means into an electric signal, and electric signal processing for processing an electric signal from the photoelectric conversion means to obtain a specific physical quantity according to the signal. And means. Further, the electric signal processing means, as described in claim 9, based on an electric signal from the photoelectric conversion means, a relative displacement between the magnetic scale and the polarization rotation means,
It can be a means for determining either the speed or the acceleration.

According to a tenth aspect of the present invention, there is provided a magnetic detection device including a magnetic scale having magnetic poles arranged at predetermined angular intervals in the circumferential direction, and a light for outputting an optical signal. Polarization of the optical signal is provided depending on the intensity of the magnetic field formed by the emitting means and the non-magnetic body on the magnetic pole exposed surface side of the magnetic scale and formed by the N-pole and S-pole magnetic poles of each set. Polarization rotating means for rotating the direction, polarization control means for transmitting only the polarized light in a specific direction, photoelectric conversion means for converting the light intensity signal after passing through the polarization control means into an electric signal, and an electric signal from the photoelectric conversion means And an electric signal processing means for calculating a specific physical quantity according to the signal. Further, the electric signal processing means is configured to detect relative angular displacement, angular velocity and angular acceleration of the magnetic scale and the polarization rotating means based on the electric signal from the photoelectric conversion means. It can be used as a means for obtaining any one of them.

In the magnetic detection device having the above structure, as described in claim 12, the magnetic scale comprises a plurality of sets of magnetic poles arranged in parallel in a plurality of rows, and the polarization rotating means has a plurality of rows. A plurality of polarization rotation elements that rotate the polarization direction of the optical signal in accordance with the strength of the magnetic field formed by the magnetic poles of each column, wherein the photoelectric conversion means transmits a plurality of light intensity signals after passing through the polarization control means. May be converted into a plurality of electric signals.

A magnetic detection device according to a thirteenth aspect of the present invention includes a magnetic pattern having a predetermined magnetic field intensity distribution composed of a plurality of magnetic field generating means, and the magnetic field intensity on the magnetic pattern side is regular in a predetermined detection direction. And a magnetic scale in which at least two magnetic poles of an N pole and an S pole which are close to each other with a non-magnetic body sandwiched therebetween in the detection direction and are exposed on the same plane side are arranged in the same row in the detection direction, The light emitting means for outputting, and the magnetic scale exposed surface side of the magnetic scale
Polarization rotating means provided at a position facing the non-magnetic body, for rotating the polarization direction of the optical signal according to the strength of the magnetic field formed by the magnetic poles of the N pole and the S pole of each set, and only the polarization of the specific direction. A polarization control means for transmitting, a photoelectric conversion means for converting a light intensity signal after transmission through the polarization control means into an electric signal, and an electric signal from a photoelectric conversion means are processed, and the magnetic scale and the Electrical signal processing means for determining at least one of displacement relative to the polarization rotation means, velocity, acceleration, angular displacement, angular velocity and angular acceleration,
According to the invention of claim 14, the magnetic scale has at least two magnetic poles of N pole and S pole arranged in the same row arranged in parallel in a plurality of rows. The polarization rotation means has a plurality of polarization rotation elements for rotating the polarization direction of the optical signal according to the strength of the magnetic field formed by the magnetic poles of each row of the plurality of rows, and the photoelectric conversion means. Converts a plurality of light intensity signals after passing through the polarization control means into a plurality of electric signals (that is,
(Corresponding to a light intensity signal of a plurality of bits). The magnetic pole arrangement of the magnetic scale in such a detection device can be realized by, for example, facing comb-shaped magnets.

Further, the magnetic scale having the above structure may be combined with another magnetic field strength detecting element to form a magnetic detecting device. That is, as set forth in claim 15 or 17, the magnetic scale having any one of the above-mentioned structures is provided at a position facing the non-magnetic body on the magnetic pole exposed surface side of the magnetic scale, and the N pole of the magnetic scale and A magnetic field strength detection element including a magnetoelectric conversion element that generates a voltage according to the strength of a magnetic field formed by an S pole, and a specific physical quantity by processing an electric signal corresponding to the generated voltage of the magnetic field strength detection element. It is possible to provide a magnetic detection device characterized by comprising:

Also in these cases, the electric signal processing means is arranged such that relative displacement, velocity and acceleration between the magnetic scale and the magnetic field strength detecting element are based on the electric signal. Any of the above can be used as a means for obtaining any one of them, and as described in claim 18, relative angular displacement, angular velocity and angular acceleration between the magnetic scale and the magnetic field strength detection element based on the electric signal. It may be a means for obtaining any one of them.

A Hall effect element or a magnetoresistive effect element can be used as the magnetoelectric conversion element. Further, it is preferable to use a magneto-optical effect element as the polarization rotating means of the magnetic detection device. In that case, polarized light in a specific direction (linearly polarized light) is incident on the magneto-optical effect element, and an external magnetic field is applied so as to be substantially orthogonal to the light, whereby the magnetic domain structure generated inside the magneto-optical effect element disappears. Then, the light traveling straight in a state where the polarization direction does not rotate passes through the polarizer (polarization control means), and an optical output is obtained. Further, when there is no magnetic field outside, due to the magnetic domain in the magneto-optical effect element which is magnetically saturated by itself, the light is
While passing through the magneto-optical effect element, its plane of polarization is rotated by 90 degrees and cannot pass through the polarizer, so there is no light output. Further, when the magnetic field generating means is a magnet, the magnet is arranged so as to be in a direction orthogonal to the displacement direction (predetermined detection direction) (parallel type), and the magnet is arranged so as to be parallel to the displacement direction. Any type of (series type) can be adopted.

[0019]

In the invention described in claims 1 to 3, the magnetic field strength detection element is
N and S poles at least two to exposed to a non-magnetic material interposed therebetween proximate the <br/> each other physician predetermined detection direction and a direction substantially orthogonal same side for being disposed in a position facing the child Since the magnetic pole is provided at the predetermined position in the predetermined detection direction, the magnetization vector emitted from the one magnetic pole on the magnetic pole surface becomes downward near the other magnetic pole located at the same height as the one magnetic pole, The direction of magnetization at the detection location is horizontal. Therefore, the magnetization in the opposite direction, which has been conventionally generated between the magnetic poles adjacent to each other in the predetermined detection direction, is effectively removed, and the problem that the effective noise level is increased by the magnetization in the opposite direction is solved.

According to the second or third aspect of the invention, among the plurality of sets of magnetic poles arranged in the detection direction, the polarities of the magnetic poles in the same row change alternately or in a predetermined order. If the polar arrangements are made different, no downward magnetization vector is generated in the vicinity of the intermediate position between the N and S magnetic poles that are close to each other in the predetermined detection direction, and the direction of the magnetization vector becomes parallel to the displacement direction. Therefore, the magnetization in the opposite direction is more surely removed. Further, by using a sensor head that can positively utilize not only the magnetic field on the magnetic pole but also the magnetization in the displacement direction generated between the adjacent magnetic poles in the displacement direction, the displacement detection and other control signals with excellent detection accuracy can be achieved. Can be recorded on the same scale.

According to the inventions of claims 4 and 5, the plurality of sets of magnetic poles or at least two magnetic poles of N pole and S pole arranged in the same row include those having different lengths in the detection direction. They are located at different heights or have different widths depending on the length of the exit surface. Therefore, the magnetic field strength at the detection height can be made uniform regardless of the size of the magnetic pole exposed area.

In a sixth aspect of the present invention, a plurality of pairs of magnetic poles or at least two magnetic poles of N pole and S pole arranged in the same row are formed by facing portions of a plurality of magnets arranged in parallel.
The number of rows is one that is obtained by subtracting 1 from the parallel number of the plurality of magnets. Therefore, the multi-channel magnetic scale can be downsized, and the manufacturing yield thereof can be improved.

According to a seventh aspect of the present invention, the plurality of sets of magnetic poles are arranged so as to be spaced at a predetermined angular interval in the circumferential direction. Therefore, the magnetic scale can detect angular displacement, angular velocity, angular acceleration, and the like. According to the eighth and ninth aspects of the present invention, the magnetic poles of the N pole and the S pole are close to each other in the direction orthogonal to the predetermined detection direction so as to face the non-magnetic body on the magnetic pole surface of the magnetic scale.
A polarization rotating means is provided in the position , and the optical signal sent from the light emitting means to the polarization rotating means rotates the polarization direction according to the strength of the magnetic field formed by the magnetic poles. Then, by interposing a polarization control means for transmitting only the polarized light in a specific direction in the path of the optical signal, a light intensity signal corresponding to the magnetic field strength is generated, and this is converted into an electric signal and signal processing is performed. The relative displacement between the magnetic scale and the polarization rotation means (including the position with one side fixed relative to the fixed side), the speed, the acceleration, and the like are obtained. At this time, the magnetization vector emerging from the positive magnetic pole on the magnetic pole surface is opposite in the vicinity of the negative magnetic pole located at the same height as this magnetic pole, but the position in the detection direction is the same. In the vicinity of the intermediate position between adjacent magnetic poles, the opposite magnetization does not occur. Therefore, the problem that the effective noise level increases due to the magnetization in the opposite direction is solved, and S /
The detector has an excellent N ratio and resolution.

According to the tenth and eleventh aspects of the present invention, the magnetic scales in which the magnetic poles are arranged in the circumferential direction are provided on the non-contact side of the magnetic pole.
A polarization rotating means is provided at a position facing the magnetic body, and an optical signal sent from the light emitting means to the polarization rotating means rotates the polarization direction according to the strength of the magnetic field formed by the magnetic poles. Then, by interposing a polarization control means for transmitting only the polarized light in a specific direction in the path of the optical signal, a light intensity signal corresponding to the magnetic field strength is generated, and this is converted into an electric signal and signal processing is performed. The relative displacement angle between the magnetic scale and the polarization rotating means (including the angular position with reference to the fixed side when one is fixed), the angular velocity or the angular acceleration, and the like are obtained. At this time, the magnetization vector emerging from the positive magnetic pole on the magnetic pole surface is opposite in the vicinity of the negative magnetic pole located at the same height as this magnetic pole, but the position in the detection direction is the same. In the vicinity of the intermediate position between adjacent magnetic poles, the opposite magnetization does not occur. Therefore, the problem that the effective noise level increases due to the magnetization in the opposite direction is solved, and the detection device has an excellent S / N ratio and resolution.

According to a twelfth aspect of the present invention, a magnetic scale having a plurality of pairs of magnetic poles arranged in parallel or having at least two magnetic poles of N pole and S pole arranged in parallel in a plurality of rows and a magnetic scale of the plurality of rows. Converting a plurality of light intensity signals into a plurality of electric signals by using a polarization rotating means having a plurality of polarization rotating elements for rotating the polarization direction of the optical signal according to the strength of the magnetic field formed by the magnetic poles of each row. Thus, it is possible to realize a so-called absolute type detection device having an excellent S / N ratio and resolution and an incremental type detection device capable of detecting the displacement direction by using two sets of magnet arrays that shift the phase of the magnetic pattern by 90 degrees.

According to the thirteenth and fourteenth aspects of the present invention, at least two magnetic poles, an N pole and an S pole, which are close to each other with a non-magnetic material interposed therebetween in the predetermined detection direction and which are exposed on the same plane side, are arranged in the predetermined detection direction. Therefore, a downward magnetization vector does not occur in the vicinity of the intermediate position between the N and S magnetic poles that are close to each other in the predetermined detection direction, and the direction of the magnetization vector is the detection direction. Therefore, in the vicinity of the middle position of the magnetic pole in the predetermined detection direction, magnetization in the opposite direction does not occur,
It is possible to avoid an effective increase in noise level.

According to the fifteenth and seventeenth aspects of the present invention, depending on the strength of the magnetic field formed by the magnetic poles of the N pole and the S pole of the magnetic scale, the magnetic scale is located at a position facing the non-magnetic body on the magnetic pole surface of the magnetic scale. A magnetic field strength detection element including a magnetoelectric conversion element that generates a voltage is provided, and an electric signal corresponding to the voltage generated by the element is processed to obtain a specific physical quantity. Therefore, the structure from the sensor head to the electric signal processing means can be simple and low in cost.

Further, in the inventions as claimed in claims 16 and 18, wherein a magneto-electric conversion element such as a magnetoresistive effect element or a Hall effect element is used as in the invention as claimed in claims 16 and 18, the invention is also based on the electric signal. One of relative displacement, velocity and acceleration between the magnetic scale and the magnetic field strength detection element, or any one of relative angular displacement, angular velocity and angular acceleration between the magnetic scale and the magnetic field strength detection element. You can ask.

[0029]

Embodiments of the present invention will be described below in detail with reference to the drawings. <First Embodiment> FIGS. 1 and 2 are views showing a magnetic scale according to a first embodiment of the present invention, which is applied to a magnetic encoder as a linear position sensor (linear position sensor). An example is shown.

First, the structure will be described. 1 (a)-
In (c), 1 is a sensor head and 10 is a magnetic scale. The sensor head 1 has, for example, a magnetic scale 10 as an axis.
It moves relative to the magnetic scale 10 by moving in the x direction (predetermined detection direction) integrally with the displacement detection target (not shown) via 19. Although not shown in detail, in the sensor head 1, for example, a known magnetic-electric conversion element, for example, a detection unit (magnetic field strength detection element) including a Hall effect element or a magnetoresistive effect element is mounted on a head body that also serves as a carriage. The generated voltage or the electric resistance is generated according to the strength of the magnetic field acting on the detector. Of course, it is needless to say that another type of sensor head having a magnetic field strength detecting element (for example, a sensor head using a magneto-optical effect element described later as the seventh embodiment) may be used.

The magnetic scale 10 has a non-magnetic material 14 having a predetermined thickness t in the y direction substantially orthogonal to the x direction (predetermined detection direction) in FIG.
At least two magnetic poles 12a and 12b of N pole and S pole which are close to each other with (thickness: t) sandwiched therebetween and which are exposed on the scale surface 10a (magnetic pole exposed surface) are set as a plurality of sets ( At least one set of magnetic poles 12a and 12b are provided at a plurality of predetermined positions with a predetermined spacing p (p> t) in the x direction, and the arrangement of the magnetic poles 12a and 12b of each set is, for example, as shown in FIG. (A) to (e) Various modes of magnetic field generating means
It is realized by 12.

In the magnetic field generating means 12 shown in FIG. 2A, both ends of a substantially horseshoe-shaped (U-shaped or U-shaped) magnet 121 are connected to the magnetic pole 1.
It is used as 2a and 12b. In the magnetic field generating means 12 shown in FIG. 2B, the L-shaped high magnetic permeability material 123 is disposed in the vicinity of the bar magnet 122 magnetized in the longitudinal direction on the side opposite to the magnetic scale surface 10a side. The magnetic pole of the S pole is induced at the end of the high magnetic permeability material 123 on the side opposite to. The magnetic field generating means 12 shown in FIG.
Direction) magnetized bar magnets 124 with high permeability material 125, 12 on both ends.
6 is arranged vertically to induce N and S magnetic poles 12a and 12b. In addition, the magnetic field generating means 12 shown in FIG.
Has a non-magnetic material 14 sandwiched between two bar magnets 127 and 128 whose magnetic poles are arranged in opposite directions.
The side magnetic poles are used as N and S magnetic poles 12a and 12b. The magnetic field generating means 12 shown in FIG. 2 (e) has a groove 129a on the wall surface portion of the bar magnet 129 facing the y-direction on the scale surface 10a side.
Is formed and both sides thereof are used as the magnetic poles 12a and 12b.

That is, the magnetic scale 10 is provided with a magnetic pattern having a predetermined magnetic field intensity distribution in which a plurality of magnetic field generating means 12 described above are embedded in the scale main body 11 made of a non-magnetic material at predetermined intervals. When the magnetic scale 10 is displaced relative to the magnetic scale 10, the intensity of the magnetic field from the magnetic pattern changes regularly in the x direction at the height in the z direction (hereinafter referred to as the detection height).

When manufacturing such a magnetic scale 10, first, the scale main body 11 made of a non-magnetic material is
A plurality of recesses for mounting the plurality of magnetic field generating means 12 are formed at a predetermined interval p in the x direction, and N magnetic poles appear in a row at predetermined intervals in the x direction in the plurality of recesses, and the N of this row is formed.
A plurality of S with a predetermined interval t in the y direction with respect to the magnetic poles of
The plurality of magnetic field generating means 12 are arranged in a line at a predetermined interval p in the x direction so that the magnetic poles of 1 appear. Next, scale surface 10a
A non-magnetic material 14 is loaded in the recess of the magnetic field generating means 12 having the N and S magnetic poles exposed above. Next, the periphery of the magnetic field generating means 12 is fixed with an adhesive agent of a non-magnetic material, and unnecessary portions near the magnetic poles 12a and 12b are removed by cutting or the like, leaving a region requiring a predetermined signal, and the shape shown in the drawing is obtained. Magnetic scale of 10 is used. The non-magnetic material 14 may be air or vacuum. Further, in this embodiment, a permanent magnet is used as the magnetic field generating means 12, but it goes without saying that it may be an electromagnet.

Next, the operation will be described. In this embodiment, y
N approaching each other in the direction and appearing on the same scale surface 10a
Since at least two magnetic poles 12a and 12b having a pole and an S pole are provided at a plurality of predetermined positions in the x direction with a predetermined space therebetween, at each position, the magnetization vector emitted from one magnetic pole 12a onto the scale surface 10a is The other magnetic pole 12b located at the same height as the one magnetic pole 12a is in the opposite direction (downward), but the position in the detection direction (x direction) is the same. Therefore, the magnetization acting on the detecting portion of the sensor head 1 has a vector in the y direction. In the x direction, the magnetic poles 12a are in the middle, and in the y direction, the magnetic poles 12a,
In the vicinity of the middle position of 12b, the sensor head 1 is not effectively magnetized in the z direction. That is, the magnetic field generating means
Since the 12 N and S magnetic poles 12a and 12b are close to each other in the y direction, the magnetizations in the opposite directions (in the + z direction) that would have been generated near the intermediate position between the single poles that are close to the x direction in the related art. (Corresponding to the magnetization in the −z direction, which acts on the magnetic field strength detection element for detecting the magnetization) is less likely to occur, and this is effectively removed. Therefore, even if a magneto-electric conversion element such as a magnetoresistive effect element or a Hall effect element is used for the detection portion of the sensor head 1 and the sensor head 1 and the magnetic scale 10 are arranged close to each other in the z direction, the magnetization in the opposite direction causes There is no conventional problem that the effective noise level increases and the S / N ratio decreases, and it is possible to detect highly accurate position or displacement with high resolution and stable output. And acceleration can be detected). <Second Embodiment> FIG. 3A is a diagram showing a magnetic scale according to a second embodiment of the present invention.

This embodiment is exactly the same as the first embodiment except for the magnetic pole arrangement. That is, as shown in FIG. 3A, a plurality of pairs of magnetic poles 12a and 12b arranged in the x direction are arranged in a plurality of magnetic poles 12a in one row (the same row) and another row (the same row). A plurality of sets of magnetic poles so that the polarity with a certain plurality of magnetic poles 12b changes in the x direction as N, S, N, S, respectively.
The polar arrangements of 12a and 12b are alternately different.

In this embodiment, the same effect as that of the first embodiment is obtained, and a plurality of magnetic poles 12 arranged in the x direction are arranged.
Since the polarities of the magnetic poles 12a or 12b in the same row among a and 12b are alternately changed, magnetization in the opposite direction (-z direction) is generated near the intermediate position between the N and S magnetic poles that are close in the x direction. Vectors are less likely to occur. Further, the magnetic poles 12a, 12
a magnetic field in the y direction on b and magnetic poles 12a adjacent to each other in the x direction,
If the magnetization in the x direction generated between the magnetic poles 12b is positively used together and the light is switched by the sensor head having the magneto-optical effect element, the functions such as resolution and direction detection can be further enhanced. Yes, an example of which will be described later.

Here, a supplementary description of the steps of detecting the displacement direction and increasing the resolution will be given with reference to FIG. 4A. When a plurality of magnetic poles 12a on the same column are alternately opposite in polarity, FIG. B
Above 4-B4, the magnetization vector (Hx) in the x direction has the maximum value or the minimum value between two magnetic poles 12a adjacent to each other in the x direction. On the other hand, above C4-C4 which is the middle of the adjacent magnetic poles 12a and 12b in the y direction, the magnetization vector (Hy) in the y direction takes the maximum value or the minimum value at the positions of the magnetic poles 12a and 12b. Therefore, when the magnetic scale 10 and the sensor head 1 are relatively displaced in the x direction (detection direction) while detecting the magnetic field strength at a plurality of locations in the y direction, the magnetic fields shown in FIGS. 4B and 4C are obtained. A signal with a phase difference of 90 degrees corresponding to the intensity distribution is obtained, and the direction of displacement (+
x or -x) can be detected. Note that the technique of dividing a signal of one cycle into multiple parts by frequency division is a well-known technique that is widely adopted in general industrial encoders that perform direction detection or other detection, and will not be described in detail here. <Third Embodiment> FIG. 3B is a diagram showing a magnetic scale according to a third embodiment of the present invention.

This embodiment is exactly the same as the second embodiment except the arrangement of the magnetic poles 12a and 12b. That is, as shown in FIG. 3B, the plurality of pairs of magnetic poles 12a and 12b arranged in the x-direction include the plurality of magnetic poles 12a in one row (the same row) and the other row (the same row). The polarities of the plurality of magnetic poles 12b in the x direction in a predetermined order (N, N, S,
N ... N, N) so that the number of pairs of magnetic poles 12a, 12 varies.
The polar arrangement of b is different.

In this embodiment, the same effect as that of the first embodiment can be obtained, and among the plurality of sets of magnetic poles 12a, 12b arranged in the x direction which is the detection direction, the magnetic pole 12a or 12 in the same row.
By changing the polarity of b in a predetermined order, it becomes possible to obtain an arbitrary signal period, and in addition to the position signal in the y direction,
There is an advantage that other control signals (for example, a control signal of a valve used together with a fluid pressure actuator, a flow control signal, etc.) can be recorded on the same scale.

Further, as shown in FIG. 4D, when the number of magnetic poles of the same polarity arranged is changed, the number of magnet rows from the reference position in the x direction, that is, the distance from the reference position in the x direction is known. It will be. For example, when there are three N poles in succession, it can be seen that the peak position is 7 to 9 from the reference position. If a plurality of magnetic poles are arranged at the same pitch, the number of the same poles is continuous. I also understand. Further, by displacing in the x direction so that a plurality of front and rear peaks can be detected, it is possible to detect the number of front and rear magnetic poles having the same polarity. Furthermore, by arranging most of the magnetic poles 12a and 12b so as to have opposite polarities alternately in the x direction, and continuously arranging magnetic poles of the same polarity in the vicinity of a position where a mechanical displacement causes a failure or is dangerous. It is also possible to generate the control signal as a danger signal. <Fourth Embodiment> FIG. 5 is a diagram showing a magnetic scale and a magnetic detection device according to a fourth embodiment of the present invention, which is applied to a magnetic rotary encoder as an angle sensor. An example is shown.

As shown in FIG. 5, in the magnetic scale 30 of this embodiment, a plurality of pairs of magnetic poles 12a and 12b are arranged at a predetermined angular interval in the R direction (circumferential direction) which is the predetermined detection direction. Therefore, the plurality of non-magnetic bodies 14 sandwiched between the plurality of sets of magnetic poles 12a and 12b are on the same circumference. In addition, a plurality of pairs of magnetic poles 12a and 12b include a plurality of magnetic poles 12a in the outer row (same row) and a plurality of magnetic poles in the inner row (same row) among them.
Plural pairs of magnetic poles 12a, 12 so that 12b have the same polarity.
The polarity arrangement of b is constant. That is, the magnetic scale 30 of the present embodiment is a disk-shaped one in which a plurality of magnetic field generating means 12 are embedded in the scale main body 31 at predetermined angular intervals so as to have the same polarity, and the magnetic scale of the first embodiment. The procedure is similar to that of 10.

Since a plurality of pairs of magnetic poles 12a and 12b are arranged in the circumferential direction at predetermined angular intervals in this way, angular position and angular displacement can be detected (of course, if signal processing is performed, angular velocity and angular acceleration can also be detected. (Possible), and moreover, highly accurate detection is possible due to the same effect as the first embodiment. Although FIG. 5 shows an example in which the magnetic pole surface is arranged on the disc, it goes without saying that the magnetic pole may be exposed on the side surface of the cylinder. <Fifth Embodiment> FIG. 6A is a view showing a magnetic scale of a fifth embodiment according to the inventions described in claims 1, 2, and 7, and
The magnetic poles are arranged differently from those in the embodiment.

As shown in the figure, in this embodiment, as in the case of the fourth embodiment, a plurality of pairs of magnetic poles 12a, 12b are separated by a predetermined angle in the R direction (circumferential direction) which is the predetermined detection direction. The plurality of non-magnetic bodies 14 arranged between the plurality of pairs of magnetic poles 12a and 12b are on the same circumference. Further, among the plurality of pairs of magnetic poles 12a and 12b, the polarities of the plurality of magnetic poles 12a in the outer row (the same row) and the plurality of magnetic poles 12b in the inner row (the same row) are alternately arranged in the R direction. N, S,
The polarities of the plurality of magnetic poles 12a and 12b are alternately changed so as to change from N to S. That is, the magnetic scale 30 of this embodiment has a plurality of magnetic field generating means in the scale body 31.
It is a disk type in which 12 are embedded at predetermined angular intervals so as to be alternately opposite in polarity, and is manufactured by substantially the same procedure as the magnetic scale 10 of the first embodiment.

In this way, the plurality of sets of magnetic poles 12a, 12b are arranged so as to be spaced at a predetermined angular interval in the circumferential direction.
Similar to the embodiment, the angular position, the angular displacement, etc. can be detected, and moreover, highly accurate detection can be achieved by the same operational effect as the first and second embodiments. <Sixth Embodiment> FIG. 6B is a diagram showing a magnetic scale of a sixth embodiment according to the invention described in claims 1, 3, and 7. The magnetic poles are arranged in different polarities from the fourth and fifth embodiments. Is different. In this embodiment, as shown in FIG.
Similar to the fourth and fifth embodiments, 12a and 12b are arranged so as to be separated by a predetermined angle in the R direction (circumferential direction). Further, among the plurality of pairs of magnetic poles 12a and 12b, the polarities of the plurality of magnetic poles 12a in the outer row (the same row) and the plurality of magnetic poles 12b in the inner row (the same row) are predetermined in the R direction. The polar arrangements of the plurality of magnetic poles 12a and 12b are different so as to change in order (for example, N, N, S, N, N, S ...). That is, the magnetic scale 30 of the present embodiment is a disk type in which a plurality of magnetic field generating means 12 are embedded in the scale body 41 at predetermined angular intervals so that the polarities change in a predetermined order.

Since a plurality of sets of magnetic poles 12a, 12b are arranged in the circumferential direction at a predetermined angular interval in this manner, the angular position, angular displacement, etc. can be detected as in the fourth and fifth embodiments. Moreover, it is possible to perform highly accurate detection due to the same effects as those of the first and third embodiments. <Seventh Embodiment> FIG. 7 is a diagram showing a seventh embodiment of the invention according to claims 1, 2, 3, 8, and 9 and shows an example applied to a magnetic encoder as a linear position sensor. There is.

In this embodiment, a plurality of pairs of magnetic poles 12a and 12b are arranged in parallel in the y direction by a predetermined number of rows in parallel and a magnetic scale 10A is used, and magneto-optical effect is used to perform magneto-optical modulation. The sensor head 21 is used. here,
Although not shown in detail in the magnetic scale 10A, for example, a plurality of magnetic scales 10 of the first, second or third embodiment are arranged in parallel and only the scale main body 11 is integrated.

Further, the sensor head 21 includes an optical waveguide forming element 22 (hereinafter simply referred to as an optical waveguide) in which a waveguide (light path) having a predetermined pattern is formed on a substrate, and the optical waveguide 22.
A polarizer 23 that is integrally mounted so as to intervene in the light traveling path and transmits polarized light in a specific direction from the incident light; and an optical waveguide.
Magneto-optical effect element 25 joined to the tip of 22 on one side
And a reflection mirror portion 26 formed on the other surface side of the magneto-optical effect element 25. Magneto-optical effect element
25 is made of, for example, a soft magnetic material, has spontaneous magnetization in a direction substantially parallel to the traveling direction of light, and is magnetically saturated inside due to the spontaneous magnetization. Then, the polarization direction of the linearly polarized light transmitted through the polarizer 23 is rotated by the magneto-optical effect element 25. Therefore, a magnetic field is caused to act on the magneto-optical effect element 25 by the magnetic poles 12a and 12b so as to orient the internal magnetization in the y direction substantially orthogonal to the light traveling direction (x direction), and the rotation of the polarization direction of the linearly polarized light is minimized. Can be Although not shown in detail, the sensor head 21 has a predetermined number of channels (for example, 2 to 16 channels) on a substrate having a predetermined shape (for example, a length of about 50 mm and a width of about 5 to 20 mm). It is provided integrally only in parallel. That is, the sensor head 21 is a sensor head for one channel of the multi-channel head,
The optical waveguide 22 is formed by, for example, forming a plurality of waveguides on the incident side (or branching into a plurality on the way) and a plurality of waveguides on the emitting side (or a single waveguide on the way). There is.

The sensor head 21 operates as follows. First, when light emitted from a light emitting means (not shown) enters the optical waveguide 22 and passes through the polarizer 23, polarized light in a specific direction (linearly polarized light) is generated, and this light is spontaneously magnetized in a certain direction. When incident on the existing magneto-optical effect element 25, its spontaneous magnetization causes rotation of the polarization direction (Faraday rotation). When an external magnetic field is applied to the magneto-optical effect element 25 by the magnetic scale 10 in the y direction of FIG. 1, the linearly polarized light advances without rotating its polarization direction.
Then, the light reaching the waveguide on the exit side with a certain probability while being reflected by the reflection mirror section 26 is transmitted through the polarizer 23 (polarization control means) as an analyzer or shielded according to the polarization direction. To be done. That is, when the sensor head 21 and the magnetic scale 10 are relatively displaced, if the strength of the magnetic field acting on the magneto-optical effect element 25 falls below a predetermined level, the light is magnetically saturated by itself.
Due to the magnetic domains in 25, the polarization direction is rotated by about 90 degrees while passing through the magneto-optical effect element 25, and thereafter the polarizer 23 cannot be transmitted, so that the sensor head 21 does not output an optical signal. On the other hand, the sensor head 21 and the magnetic scale 10
When a magnetic field in the y direction is applied to the magneto-optical effect element 25 by the magnetic scale 10 due to the relative displacement of, the magnetic domain structure generated inside the magneto-optical effect element 25 disappears, and the linearly polarized light is The sensor head 21 outputs an optical signal because it moves forward without rotating the polarization direction (of course, the presence or absence of the output can be reversed by disposing the analyzer in different directions). In this way, the magnetic scale 10 and the sensor head 21
An optical signal is output from the sensor head 21 to an optical signal processing circuit (not shown) composed of an opto-electric conversion means and a signal processing means in accordance with the relative displacement between The optical signal processing circuit corresponds to a controller connected to the sensor head 1 or a laser diode, a photodiode and a controller connected to the sensor head 21, which will be described later in detail in twelfth to sixteenth embodiments. The detailed description here is limited to the magnetic scale.

In this embodiment, the magnetic pole 12 of the magnetic scale 10A is used.
In addition to the same effects as those of any of the first to third embodiments, the sensor head 21 can be obtained depending on the polar arrangement of a and 12b.
However, since it is configured as a multi-channel head in which the optical waveguide 22, the polarizer 23, the magneto-optical effect element 25, and the reflection mirror section 26 are integrated on the same substrate, it is easy to manufacture a small and lightweight sensor head even with multiple channels. can do.

In the present embodiment, the magnetization vector of the magnetic pole N of the magnetic poles 12a and 12b on the magnetic pole surface 10a is directed downward until the magnetic pole of S located at the same height as this magnetic pole is directed downward. Heading toward one side in the y direction at substantially the same position in the x direction. Further, the distance p between the magnetic poles 12a adjacent to each other in the x direction is sufficiently larger than the distance t between the magnetic poles 12a and 12b (N, S) adjacent to each other in the y direction, and the magnetic poles 12a adjacent to each other in the x direction. Magnetic poles 12a and 12b in the vicinity of the intermediate position between the two and 12b
It is difficult for the magnetization to wrap around in the opposite direction (on the other side in the y direction). Therefore, the magnetic poles 12a that are close to each other in the x direction,
In the vicinity of the intermediate position between b, the magnetic field in the y direction is
Without effectively acting on the magneto-optical effect element 25 of
The conventional problem that the effective noise level is increased by the magnetization in the opposite direction is surely solved, and the detector has an excellent S / N ratio and resolution.

Furthermore, when the polar arrangement of the magnetic poles of the magnetic scale 10A is the same as in the second or third embodiment, the magnetic poles are
The magnetic field in the y direction on 12a and 12b and the magnetic poles 12 adjacent in the x direction
It is possible to positively utilize both the magnetizations in the x direction generated between a and between the magnetic poles 12b to perform the light modulation function (light switching function) of the sensor head 21 and further improve the resolution. <Eighth Embodiment> FIGS. 8 (a) and 8 (b) show claims 1, 2 and
It is a figure which shows 8th Example which concerns on 3, 4, 13, 14 invention.

As shown in FIGS. 9A and 9B, in this embodiment, a plurality of pairs of magnetic poles 12a and 12b (at least N pole and S pole arranged in the same row as in a tenth embodiment described later) are used. Two magnetic poles may be used), but the magnetic poles 12a ₁ and 12 have the same width in the y direction and different lengths in the x direction (predetermined detection direction).
a _2, 12b _1, includes a 12b _2, magnetic poles 12a, 12
The exposed surfaces e ₁ and e _{2 of} b are lengths L ₁ in the detection direction,
It is located at a different height by a step h according to the ratio of L ₂ (ratio of areas). Specifically, the longer magnetic poles 12a ₂ and 12b ₂
A magnet having a small height is used as the magnet forming the magnet, or the cutting amount after being embedded in the scale main body 11 is made different, so that the longer the magnet (larger area), the lower the height is set. On the detection side, the above-mentioned sensor head 1 or 21 and the optical signal processing circuit (comprising an opto-electric conversion means and a signal processing means (not shown)) connected thereto are used.

In this embodiment, the same effect as that of the first embodiment can be obtained, and in addition, a plurality of pairs of magnetic poles 12a and 12b (or at least two magnetic poles of N pole and S pole arranged in the same row) are provided. Magnetic poles 12a ₁ , 12a ₂ , 12 having different lengths in the x direction
b ₁ and 12 b ₂ , and the exposed surfaces e ₁ and e _{2 of} those magnetic poles are x.
Since they are located at different heights depending on the lengths L ₁ and L ₂ (L ₁ <L ₂ ) in the direction, for example, the output signal level of the sensor head 1 corresponding to the magnetic field applied from the magnetic poles 12a ₂ and 12b _2. However, the signal level becomes lower by the step h and changes from the signal level of the virtual line shown in FIG. 8A to the signal level of the solid line in FIG. In this way, the magnetic field strength generated in the vicinity of the detection height of the sensor head 1 or 21 can be made uniform irrespective of the size of the magnetic pole exposed area, so that the detection accuracy can be stabilized. <Ninth Embodiment> FIG. 8 (c) shows the features of claim 1, 2, 3, 6,
It is a figure which shows the 9th Example which concerns on invention of 13 and 14.

As shown in FIG. 7C, in this embodiment, a plurality of pairs of magnetic poles 12a and 12b (with at least two magnetic poles N and S arranged in the same row as in the tenth embodiment described later) are used. Magnetic poles having different widths in the y direction
12a ₁ , 12a ₂ , 12b ₁ , 12b ₂ are included, and these magnetic poles
The exposed surfaces of 12a and 12b have a length L ₁ in the detection direction,
Different widths w ₁ and w ₂ (w ₁ > w ₂ ) are set according to the ratio (area ratio) of L ₂ (L ₁ <L ₂ ). In particular,
Longer magnets (larger areas) can be obtained by using magnets that form the longer magnetic poles 12a ₂ and 12b ₂ with smaller width dimensions, or by differentiating the width direction cutting amount after embedding in the scale body 11. The width is narrow. The structure of the detection side is exactly the same as that of the eighth embodiment.

Also in this embodiment, the same effect as that of the eighth embodiment can be obtained. The height in the z direction may be adjusted according to the magnetic pole exposed area as in the eighth embodiment, and the width in the y direction may be adjusted together with the height. <Tenth Embodiment> FIGS. 9A to 9C are views showing a magnetic scale of a tenth embodiment according to the invention of claims 13 and 14, respectively, and showing a magnetic encoder as a linear position sensor. The applied example is shown.

As shown in the figure, in the magnetic scale 40 of this embodiment, the N pole of one magnet 41 and the S pole of the other magnet 42 of the two magnets are respectively moved in the X direction (predetermined detection direction). Forming a plurality of magnetic pole projections 41a, 42a spaced apart by a predetermined distance,
Both magnets 41 and 42 are opposed to each other in the y direction so that the magnetic pole convex portions 41a and 42a are alternately arranged in the x direction. Then, at least two magnetic pole convex portions 41a, 42a (magnetic poles) of N pole and S pole which are adjacent to each other in the x direction and appear on the same surface (on the same surface side) are arranged in the same row in the x direction, and y In the direction, each magnetic pole convex portion 41a or 42a is brought close to the opposite polarity magnet 42 or 41.

That is, the magnetic scale 40 of this embodiment is
The magnetic pole arrangement in which the N-pole and S-pole magnetic poles 41a and 42a are arranged on the same row is simply realized by abutting the comb-shaped magnets 41 and 42 as shown in FIG. 9A. , A magnetic pattern having a predetermined magnetic field strength distribution, which is composed of a plurality of sets of magnetic pole convex portions 41a and 42a (magnetic field generating means) of a plurality of magnets 41 and 42.

Further, in this embodiment, a sensor head having a polarization rotating means (magneto-optical effect element) for detecting a magnetic field in the z direction is provided, and specifically, the above-mentioned sensor head 21 is used. ing. In this case, the sensor head
21 is arranged such that the magneto-optical effect element 25 is biased to one side of the magnets 41 and 42 and the traveling direction of light is in the x direction. In the sky between the magnetic poles 41a and 42a, The magnetic field between the magnets 41 and 42 in a direction substantially parallel to the traveling direction (x direction) of the magnets, and the x direction parallel to the traveling direction of the light during the displacement, and the + z direction (in this case, the magneto-optical effect element 25). The direction of the magnetic field that eliminates the spontaneous magnetization of the magnetic field) is applied.

In this embodiment, at least two magnetic poles 41a and 42a, which are close to each other in the x direction and which are exposed on the same scale surface, are arranged in the x direction, which is the predetermined detection direction. A magnetic circuit from N to S is formed in the x direction, and the direction of the magnetization vector near the intermediate position between the magnetic pole projections 41a and 42a of the N pole and the S pole that are adjacent in the x direction is x.
The direction and the direction of the magnetic field on the magnetic poles 41a and 42a are the + z direction. Therefore, the effective magnetic field in the −z direction does not act on the sensor head 21 at the intermediate position between the magnetic poles 41a and 42a, which increases the effective noise level and increases the S / N ratio.
The problem that the ratio is lowered does not occur.

Further, as shown in FIG. 9 (b), a plurality of comb-shaped magnets 41, 42, 43 (only the S pole side of 43 is shown, and the magnet below it is not shown) N The pole and S pole magnetic pole projections 41a, 42a, 42b, 43a are arranged such that at least two magnetic poles of N pole and S pole are arranged side by side in each row of a plurality of rows with the air layer 14 sandwiched therebetween, and thereby a plurality of poles are formed. It is also possible to detect the light intensity signal of the bit. Of course, as shown in FIG. 9C, a plurality of magnets 45 and a non-magnetic material are used.
14 and (for example, both are plate-shaped) may be arranged alternately so as to have opposite polarities, and at least two magnetic poles of N pole and S pole may be arranged in the same row. <Eleventh Embodiment> FIG. 10 is a diagram showing a magnetic scale for angle detection of an eleventh embodiment according to the invention as claimed in claims 13 and 14. The sensor head of this embodiment has the same structure as the sensor head 21 of the tenth embodiment, for example.

As shown in the figure, in this embodiment, one of the two magnets, which is the inner peripheral portion of the annular magnet 51, has the N pole,
To the S pole which is the outer peripheral portion of the other disk-shaped or annular magnet 52,
A plurality of magnetic pole projections 51a and 52a are formed at predetermined intervals in the R direction (circumferential direction) which is the predetermined detection direction, and both magnets 51 and 52 are alternately arranged in the R direction in the magnetic pole projections 51a and 52a. So that they butt inward and outward in the radial direction. And R
At least two magnetic pole convex portions 51a and 52a (magnetic poles) which are close to each other in the direction and are exposed on the same surface side are arranged in the same row in the R direction. That is, in this embodiment,
As shown in FIG. 10, the curved comb-shaped magnets 51 and 52 are abutted inside and outside to easily realize the magnetic pole arrangement such that the N-pole and S-pole magnetic poles 51a and 52a are arranged in the same row. And a plurality of sets of magnetic pole projections 51a, 52a of a plurality of magnets 51, 52
A magnetic pattern having a predetermined magnetic field intensity distribution (magnetic field generating means) is provided.

As described above, in the present embodiment, at least two magnetic poles 51a and 52a which are close to each other in the x direction and appear on the same scale surface on the same scale surface have the predetermined detection direction R.
Since they are arranged in the same direction, angular displacement (including the other angle based on one side), angular velocity or each velocity can be detected, and detection with excellent detection accuracy is achieved by the same effect as in the tenth embodiment. Will be possible. <Twelfth Embodiment> FIG. 11 shows claims 1, 2, 3, 6, and 1.
It is a figure which shows the magnetic scale and magnetic detection apparatus of the 12th Example which concerns on invention of 5 and 16. The sensor head of this embodiment is, for example, one in which a plurality of the sensor heads 1 or 21 of the above-described example are provided in parallel in the y direction.

As shown in the figure, in the magnetic scale 60 of this embodiment, a plurality of magnets 61, 62, 63, 64 are non-magnetic between them in the y direction orthogonal to the X direction (predetermined detection direction). The body 65 is arranged in parallel to a linear scale main body (not shown), and a plurality of pairs of magnetic poles N and S forming a plurality of rows are provided to the plurality of magnets 61 to 64 by the facing portions of the plurality of magnets 61 to 64. The number of columns (3 in this case) obtained by subtracting 1 from the number of parallel lines (4 in this case) is configured. The distance between the magnetic poles N and S below the uppermost magnetic poles N and S is narrower, and the distance between the magnetic poles N and S lower than that is the narrowest. There is. However, arbitrary magnetic pole intervals which are not the same can be set by appropriately removing magnetic poles from the illustrated magnetic scale 60 or by making the lengths of the magnetic poles different in the x direction. In addition, in the magnetic scale 60, the magnets 61 to 64 are divided into a plurality of blocks (two blocks are shown in the drawing) and the magnets 61 to 64 are divided into a plurality of blocks.
Are arranged at a predetermined interval in the x direction to form a magnetic pattern having a predetermined magnetic field strength distribution.

As described above, the plurality of magnets 61 arranged in parallel are arranged.
~ 64 facing portions, a plurality of pairs of magnetic poles N,
Since S is constituted by the number of rows obtained by subtracting 1 from the parallel number of the plurality of magnets 61 to 64, the magnetic scale 60 for detecting the linear position of the multi-channel can be easily manufactured, and like the first embodiment. The number of bits can be increased while improving the S / N ratio, and the resolution in the displacement direction can be improved.

The facing portions of the magnets 61 to 64 are comb-shaped having a plurality of magnetic pole convex portions as in the tenth embodiment, and at least two magnetic poles of N pole and S pole arranged in the same row are magnetized. It is also possible to configure the number of columns by subtracting 1 from the parallel number of 61 to 64. Further, in the magnetic detection device according to the present embodiment, the sensor head 1 provided on the magnetic pole exposed surface side of the magnetic scale 60 generates an electric resistance or a generated voltage according to the strength of the magnetic field from the magnetic scale 60. A controller 70 (electrical signal processing means) having a magnetic field strength detecting element composed of (a magnetoresistive effect element or a Hall effect element) and connected to a plurality of sensor heads 1 corresponds to the electric resistance or the generated voltage of the magnetic field strength detecting element. The electric signal to be processed is processed to obtain a specific physical quantity. That is, in this embodiment, on the magnetic pole surface of the magnetic scale 60, a plurality of magnetic field intensity detection elements corresponding to the outputs of the magnetic field intensity detection elements are formed according to the intensity of the magnetic field formed by the magnetic poles N and S of the plurality of columns of the magnetic scale 60. For example, the position information is obtained by processing the different electric signals for the columns by a known method. Ie magnetic scale
The 60 magnetic patterns and the sensor heads 1 for a plurality of rows can function as a so-called absolute encoder. Of course, magnetic scale 60 and sensor head 1
It is also possible to determine any one of displacement, velocity, and acceleration relative to the detection unit (magnetic field strength detection element). It is also possible to use a so-called incremental encoder that detects the displacement direction by using a signal of a plurality of bits. Then, the resolution and the S / N ratio can be improved by the same effect as that of the first embodiment, and a highly accurate magnetic detection device can be obtained. Further, by using the sensor head 1, the structure of the sensor head and the controller 70 can be made simple and low in cost as compared with the case of the magneto-optical modulation, while improving the S / N ratio and the resolution as described above. You can

It goes without saying that the sensor head 21 for performing magneto-optical modulation can be used as the sensor head. When this sensor head 21 is used, this embodiment is not the embodiment according to claims 15 and 16 but the embodiment according to the invention of claims 8 and 9. <Thirteenth Embodiment> FIG. 12 shows claims 1, 2, 3, 6, 7,
It is a figure which shows the magnetic scale and magnetic detection apparatus of 13th Example based on invention of 15-18.

This embodiment is the magnetic scale of the twelfth embodiment.
A disk-shaped magnetic scale is used instead of 60, and the other structure is the same as that of the twelfth embodiment. As shown in the figure, in the magnetic scale 80 of the present embodiment, the scale main body 81 has a plurality of blocks of magnets 61 substantially similar to those of the twelfth embodiment.
.About.64 (constituting a plurality of sets of magnetic poles) are arranged at predetermined angular intervals in the R direction (circumferential direction) which is the detection direction.

As described above, as in the twelfth embodiment, a plurality of pairs of magnetic poles N and S forming a plurality of rows are arranged in parallel by the facing portions of the plurality of magnets 61 to 64 arranged in parallel. Since the number of rows obtained by subtracting 1 from the number is configured, the magnetic scale 80 for detecting the rotational position of the multi-channel can be easily manufactured. Further, the magnetic detection device of the present embodiment can be made to function as a so-called absolute type rotary encoder by the controller 70, and the relative angular displacement, angular velocity and angular acceleration of the magnetic scale 80 and the magnetic field strength detection element. Either of them can be requested.
Further, similar to the first and twelfth embodiments, while adopting the sensor head 1 using the magnetoresistive effect element or the Hall effect element, excellent detection accuracy is obtained by improving the S / N ratio and ensuring high resolution. be able to.

Needless to say, the sensor head 21 for performing magneto-optical modulation can also be used as the sensor head in this embodiment. When the sensor head 21 is used, this embodiment is not an embodiment according to claims 15 to 18, but an embodiment according to the invention of claims 10 and 11. <Fourteenth Embodiment> FIG. 13 is a view showing a magnetic scale and a magnetic detection device according to a fourteenth embodiment of the invention described in claims 1, 2, 3, 8, and 9.

As shown in the figure, the magnetic detection device of this embodiment outputs a magnetic scale 10 similar to that of the first embodiment and an optical signal corresponding to a drive signal from a known light emission drive circuit 101. A laser diode 91 (light emitting means), a sensor head 21 provided on the magnetic pole surface of the magnetic scale 10,
A photodiode 95 (photoelectric conversion means) for converting a light intensity signal after passing through the sensor head 21 into an electric signal, and an electric signal from the photodiode 95 is processed to obtain a specific physical quantity according to those signals. The controller 100 (electrical signal processing means) is provided. Here, the magneto-optical effect element 25 of the sensor head 21 includes the N and S magnetic poles 12 of each set.
Depending on the strength of the magnetic field formed by a and 12b, the polarization direction of the optical signal after passing through the polarizer 23 is rotated about 90 degrees (for example, by spontaneous magnetization when the magnetic field from the magnetic scale 10 falls below a predetermined level). It serves as a polarization rotating means.
In addition, the polarizer 23 transmits only the polarized light in the specific direction out of the light from the laser diode 91 to generate a linearly polarized optical signal, and only the polarized light in the specific direction in the light path after passing through the magneto-optical effect element 25. It also serves as an analyzer (polarization control means) for transmitting light. The controller 100 includes a comparator 102 that inputs an electric signal from the photodiode 95.
A counter 103 for counting the number of output pulses of the comparator 102 corresponding to the displacement amount, and a counter 1 for every predetermined time.
A count value of 03 is input and stored, and a subtracter 104 that calculates the count value per predetermined time corresponding to the speed by subtracting the previous count value from this count value and It also has a function of controlling the circuit 101. Note that the output of the subtractor 104 may be further taken into another subtractor to calculate the speed change per predetermined time to detect the acceleration. Ie controller
Reference numeral 100 is a means for obtaining any one of the relative displacement between the magnetic scale 10 and the sensor head 21, the speed, and the acceleration based on the electric signal from the photodiode 95.

In the present embodiment, the magnetic scale 10 in which the N and S magnetic poles 12a and 12b are brought close to each other in the direction orthogonal to the constant detection direction.
A sensor head 21 having a magneto-optical effect element 25 is provided on the magnetic pole surface of the magnetic pole, and the optical signal sent from the laser diode 91 to the magneto-optical effect element 25 becomes the strength of the magnetic field formed by the magnetic poles 12a and 12b. The polarization direction is rotated accordingly. And a polarizer that transmits only polarized light in a specific direction
By interposing 23 in the path of the optical signal, a light intensity signal corresponding to the magnetic field intensity is created, and this is converted into an electric signal by the photodiode 95 and subjected to signal processing, and the magnetic scale 10 and the sensor head which are specific physical quantities. The relative displacement with respect to 21 (for example, the position on the movable side when one is fixed), the velocity, or the acceleration is obtained. At this time, similarly to the seventh embodiment, in the vicinity of the intermediate position between the magnetic poles 12a or 12b which are close to each other in the x direction, it is extremely difficult to generate magnetization in the opposite direction which produces an effective noise component. Therefore, the problem that the effective noise level increases due to the magnetization in the unnecessary direction is solved, and the magnetic detection device is excellent in the S / N ratio and the resolution as in the seventh embodiment. <Fifteenth Embodiment> FIG. 14 shows the features of claims 1, 2, 3, 8, 9,
It is a figure which shows the magnetic scale and magnetic type detection apparatus of the 15th Example which concerns on 12th invention.

As shown in the figure, this embodiment is a multi-channel magnetic detection device using the magnetic scale 60 of the thirteenth embodiment and a plurality of sensor heads 21. That is, in the y direction orthogonal to the X direction (predetermined detection direction),
A plurality of magnets 61, 62, 63, 64 are arranged in parallel to form a plurality of pairs of magnetic poles N, S. Further, the magnetic detection device of the present embodiment includes laser diodes 91, 92, 93 (light emitting means) for outputting an optical signal, a sensor head 21 provided on the magnetic pole surface of the magnetic scale 60, and a sensor head.
Photodiodes 95, 96 and 97 (photoelectric conversion means) for converting the light intensity signal after passing through 21 into an electric signal and a drive signal to the light emitting means 91 to 93 and the electric power from the photodiodes 95 to 97. A controller 100 (electrical signal processing means) for processing signals to obtain a specific physical quantity according to the signals. Here, the magneto-optical effect element 25 of the sensor head 21 uses a laser depending on the strength of the magnetic field from the magnetic poles N and S (for example, by spontaneous magnetization when the magnetic field from the magnetic scale 60 is below a predetermined level due to displacement). It serves as a polarization rotation means for rotating the polarization direction of the optical signal from the diode 91, 92 or 93. Also, the polarizer 23
Is a linearly polarized optical signal by transmitting only the polarized light of a specific direction out of the light from the laser diodes 91, 92, 93, and in the light path after passing through the magneto-optical effect element 25,
It also serves as an analyzer (polarization control means) that transmits only polarized light in a specific direction.

Although not shown in detail, the controller 100 has a CPU, a ROM in which a predetermined processing program is stored in advance, a CPU and a RAM for exchanging data with the ROM, a light emission drive circuit 101 and a photodiode 9.
ROM composed of I / O circuit etc. connected to 5
According to a predetermined control program stored in advance, based on the electrical signals from the photodiodes 95 to 98, the relative displacement between the magnetic scale 60 and the sensor head 21, the velocity or acceleration is calculated, or one side, for example the sensor The position of the magnetic scale 60 when the head 21 is fixed can be obtained. Of course, by converting a plurality of light intensity signals into a plurality of electric signals to form a signal of a plurality of bits including position information,
It can function as a so-called absolute type linear encoder or the like.

In the present embodiment, the magnetization vector emerging from the magnetic pole N on the magnetic pole exposed surface is directed toward the one side in the y direction until it becomes downward near the magnetic pole S located at the same height as this magnetic pole. The distance between the magnetic poles that are close to each other in the x direction is sufficiently larger than the distance between the magnetic poles of N and S that are adjacent to each other in the y direction. Therefore, in the vicinity of the intermediate position between the magnetic poles that are close to each other in the x direction, there is no wraparound of the magnetization in the direction opposite to that on the magnetic poles N and S (the other side in the y direction). Therefore, the problem that the effective noise level increases due to the magnetization in the opposite direction is solved as in the above-described embodiment, and the detection device has an excellent S / N ratio and resolution.

Although the sensor head 21 using the magneto-optical effect element in the above-mentioned embodiment is of the reflective type having the reflective surface, it goes without saying that it may be of the transmissive type.

[0077]

According to the first aspect of the invention, the magnetic field generated in the direction opposite to the direction of the magnetic field to be detected between the adjacent magnetic poles sandwiching the non-magnetic material in the predetermined detection direction is effectively removed. Therefore, even if a magnetic field strength detection element such as a magnetoresistive effect element or a Hall effect element is used, there is no problem that the effective noise level increases due to magnetization in the opposite direction, and the distance between the magnetic scale and the magnetic field strength detection element is reduced. Can be narrowed. As a result, the resolution and S of the detector using it
The / N ratio can be improved.

According to the invention described in claim 2, since the polarities of the magnetic poles in the same row are alternately changed, the effect of the invention described in claim 1 can be made more remarkable, and only the magnetic field on the magnetic poles can be made. Instead, it is possible to further improve the detection accuracy by using the sensor head that can positively utilize the magnetization generated between the adjacent magnetic poles in the predetermined detection direction. According to the invention of claim 3, since the polarities of the magnetic poles in the same row are changed in a predetermined order, the effect of the invention of claim 1 can be made more remarkable, and only the magnetic field on the magnetic poles can be obtained. Instead, it is possible to further improve the detection accuracy by using the sensor head that can positively utilize the magnetization generated between the adjacent magnetic poles in the predetermined detection direction.

According to the fourth aspect of the invention, at least two magnetic poles of the plurality of sets or N poles and S poles arranged in the same row are provided.
Since the two magnetic poles are positioned at different heights depending on the length of the exposed surface in the detection direction, the magnetic field strength at the detected height can be made uniform regardless of the size of the exposed area of the magnetic pole. The detection accuracy can be stabilized. Claim 5
According to the described invention, the plurality of sets of magnetic poles or at least two magnetic poles of N pole and S pole arranged in the same row have different widths orthogonal to the detection direction according to the detection direction length of the exposed surface. Therefore, the magnetic field strength at the detection height can be made uniform regardless of the size of the magnetic pole exposed area, and the detection accuracy can be stabilized.

According to the sixth aspect of the present invention, a plurality of pairs of magnetic poles or N arranged in the same row are arranged by the number of rows obtained by subtracting 1 from the parallel number of the magnets by the facing portions of the plurality of magnets arranged in parallel.
Since at least two magnetic poles of the pole and the S pole are formed, a multi-channel magnetic scale can be easily manufactured. According to claim 7, since the plurality of sets of magnetic poles are arranged so as to be spaced at a predetermined angular interval in the circumferential direction,
It is possible to detect at least one of angular displacement (including angular position with reference to the fixed side), angular velocity and angular acceleration,
Moreover, it is possible to provide a magnetic scale having excellent detection accuracy.

According to the present invention, the polarization rotating means is provided at a position facing the non-magnetic body on the magnetic pole exposing surface side of the magnetic scale, and the polarization direction of the optical signal sent to the polarization rotating means is set to the magnetic pole. Is rotated in accordance with the strength of the magnetic field in the predetermined direction formed by the above, and the polarization control means is interposed in the path of the optical signal to generate a light intensity signal corresponding to the magnetic field strength, and this is converted into an electrical signal for signal processing. Therefore, it is possible to prevent the occurrence of the magnetization in the opposite direction to the magnetization direction to be detected between the magnetic poles that are close to each other in the detection direction, and solve the problem that the effective noise level increases due to the magnetization in the opposite direction.
It is possible to provide a magneto-optical modulation type magnetic detection device having an excellent S / N ratio and resolution and high detection accuracy.

According to the ninth aspect of the invention, at least one of relative displacement (including a position on the fixed side as a reference) between the magnetic scale, which is a specific physical quantity, and the polarization rotating means, velocity and acceleration. One can be accurately determined. According to the invention as set forth in claim 10, the magnetic scales in which the plurality of sets of magnetic poles are arranged in the circumferential direction are arranged on the magnetic pole surface side of the magnetic scale.
Polarization rotating means is provided at a position facing the magnetic body, the polarization direction of the optical signal is rotated according to the strength of the magnetic field in a predetermined direction formed by the magnetic pole, and the polarization control means is interposed in the path of the optical signal. Since a light intensity signal corresponding to the magnetic field strength is generated and converted into an electric signal for signal processing, it is possible to prevent the magnetization in the direction opposite to the predetermined magnetic field direction between the magnetic poles that are close to each other in the detection direction. It is possible to prevent the problem of an increase in effective noise level due to magnetization in the opposite direction, and to provide a magneto-optical modulation type magnetic detection device having excellent S / N ratio and resolution and high detection accuracy. it can.

According to the eleventh aspect of the present invention, the relative displacement angle between the magnetic scale, which is a specific physical quantity, and the polarization rotating means (including the angular position with one side fixed relative to the fixed side). , At least one of the angular velocity and the angular acceleration can be accurately obtained. According to the twelfth aspect of the invention, the polarization direction of the optical signal is rotated according to the magnetic scale in which a plurality of pairs of magnetic poles are arranged in parallel in a plurality of rows and the strength of the magnetic field formed by the magnetic poles in each of the plurality of rows. A polarization rotating means having a plurality of polarization rotating elements is used, so that by converting a plurality of light intensity signals into a plurality of electric signals, a so-called absolute type detection device excellent in S / N ratio and resolution can be obtained. Can be realized.

According to the thirteenth aspect of the present invention, at least two magnetic poles, an N pole and an S pole, which are close to each other with a non-magnetic material interposed therebetween in the predetermined detection direction and which are exposed on the same plane side, are arranged in the predetermined detection direction. Since the downward magnetization is not generated between the magnetic poles of the N pole and the S pole which are adjacent to each other in the detection direction, a magnetic field strength detection element including a magnetoelectric conversion element such as a magnetoresistive effect element or a Hall effect element is used. However, there is no problem that the effective noise level is increased by the magnetization in the opposite direction, and the gap between the magnetic scale and the magnetic field strength detection element can be narrowed. As a result, the resolution and S / N ratio of the detection device can be improved. Further, if a sensor head that can positively utilize not only the magnetic field on the magnetic poles but also the magnetization generated between the adjacent magnetic poles in the predetermined detection direction, the detection accuracy can be further improved.

According to the fourteenth aspect of the invention, the magnetic scale is formed by arranging at least two magnetic poles of N poles and S poles arranged in the same row in parallel in a plurality of rows, and magnetic poles in each row of the plurality of rows. Since the polarization rotating means having a plurality of polarization rotating elements for rotating the polarization direction of the optical signal according to the strength of the magnetic field is used, by converting the plurality of light intensity signals into a plurality of electric signals, S / It is possible to realize a so-called absolute type detection device having excellent N ratio and resolution.

According to the fifteenth aspect of the invention, the voltage corresponding to the strength of the magnetic field formed by the plurality of sets of the N-pole and the S-pole at the position facing the non-magnetic body on the magnetic pole surface of the magnetic scale. Since a magnetic field strength detection element composed of a magneto-electric conversion element for generating is provided and an electric signal corresponding to the voltage generated by the detection element is processed to obtain a specific physical quantity, the S / N ratio and the resolution are improved. However, the structure of the sensor head and the electric signal processing means can be made simple and low cost.

According to the sixteenth aspect of the invention, even when a magnetoelectric conversion element such as a magnetoresistive effect element or a Hall effect element is used as the magnetic field strength detection element, the magnetic scale and the magnetic field strength detection element which are specific physical quantities are It is possible to accurately determine at least one of the relative displacement (including the position with the fixed side as a reference), the speed, and the acceleration.

According to the invention of claim 17, a plurality of N
Magnets with poles and S poles arranged in the circumferential direction at predetermined intervals
Qi scale magnetic pole surface sidePosition facing the non-magnetic material of
The strength of the magnetic field formed by the N and S poles
Magnetic field consisting of magneto-electric conversion element that generates voltage according to
An intensity detection element is provided, and electricity corresponding to the voltage generated by the element is detected.
Since the signal is processed to obtain a specific physical quantity, the angle detection
While improving the S / N ratio and resolution at the time of output, etc.
The sensor head and electrical signal processing means are simple and low
Can be of cost.

According to the eighteenth aspect of the present invention, the relative displacement angle between the magnetic scale, which is a specific physical quantity, and the magnetic field strength detection element (including the angular position with the fixed side as a reference),
At least one of the angular velocity and the angular acceleration can be accurately obtained.

[Brief description of drawings]

1A and 1B are views showing a first embodiment of the present invention, in which FIG. 1A is a perspective view of a linear type linear sensor including a magnetic scale and a sensor head, FIG. 1B is a plan view of the sensor, and FIG.
FIG. 7B is a sectional view taken along line C1-C1 of FIG.

FIG. 2 is a cross-sectional view of a magnetic scale showing five modes of the magnetic field generating means.

FIG. 3 is a schematic plan view of second and third embodiments of the present invention,
(A) shows the magnetic scale of the second embodiment in which the arrangement of the magnetic poles is alternately changed, and (b) shows the magnetic scale of the third embodiment in which the arrangement of the magnetic poles is changed in a predetermined order.

4A to 4C are explanatory views of the magnetic field strength distribution in the second embodiment shown in FIG. 3A, and FIG. 4D is a diagram showing a modification of the magnetic pole arrangement of the third embodiment. Is.

FIG. 5 is a schematic front view of the magnetic rotary encoder according to the fourth embodiment of the present invention.

6A is a front view showing a magnetic scale according to a fifth embodiment of the present invention, and FIG. 6B is a front view showing a magnetic scale according to the sixth embodiment of the present invention. The magnetic poles are arranged in different polarities.

FIG. 7 is a schematic plan view of the magnetic linear encoder showing a seventh embodiment of the present invention.

FIG. 8 is an explanatory view of eighth and ninth embodiments of the present invention,
(A) and (b) show the eighth embodiment in which the height of the magnetic pole exposed surface is different, and (c) shows the ninth embodiment in which the width of the magnetic poles orthogonal to the detection direction is different.

9A is a plan view showing a magnetic scale according to a tenth embodiment of the present invention, FIG. 9B is a plan view showing a mode when a multi-head is used, and FIG. 9C is a non-magnetic view of a plurality of plate-shaped magnets. It is a perspective view showing the mode arranged in the same line on both sides of the body.

FIG. 10 is a plan view showing a magnetic scale for angle detection according to an eleventh embodiment of the present invention.

FIG. 11 is a main part configuration diagram showing a magnetic scale and a magnetic detection device according to a twelfth embodiment of the present invention.

FIG. 12 is a main part configuration diagram showing a magnetic scale and a magnetic detection device of a thirteenth embodiment of the present invention.

FIG. 13 is a main part configuration diagram showing a magnetic scale and a magnetic detection device according to a fourteenth embodiment of the present invention.

FIG. 14 is a main part configuration diagram showing a magnetic scale and a magnetic detection device according to a fifteenth embodiment of the present invention.

FIG. 15 is an explanatory diagram of a problem of the conventional example.

[Explanation of symbols]

1 Sensor head (magnetic field strength detection element) 10, 30, 40, 60, 80 Magnetic scale 10a Scale surface (magnetic pole surface) 11, 31, 41, 81 Scale main body 12 Magnetic field generating means 12a, 12b, 41a, 42a Plural sets Magnetic pole 14 Non-magnetic material 21 Sensor head (sensor head using magneto-optical effect element) 22 Optical waveguide (optical waveguide forming element) 23 Polarizer (polarization control means) 25 Magneto-optical effect element (polarization rotation means) 41, 42 , 51, 52, 61, 62, 63, 64 Magnets 41a, 42a, 51a, 52a Magnetic pole projections (magnetic poles, magnetic field generating means) 91, 92, 93 Laser diodes (light emitting means) 95, 96, 97 Photodiodes 95 (Photoelectric conversion means) 100 controller (electrical signal processing means) c ₁ , c ₂ exposed surface L ₁ , L ₂ magnetic pole length w _{1 in} the detection direction, w ₂ magnetic pole width orthogonal to the detection direction

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Tsutomu Takahashi 1110-1 Ozaki, Miyashiro, Tarui-cho, Fuwa-gun, Gifu Teijin Seiki Co., Ltd. Gifu No. 1 factory (56) Reference JP-A-1-224623 (JP, A) JP 60-119413 (JP, A) JP 4-351916 (JP, A) JP 63-148104 (JP, A) JP 59-188519 (JP, A) JP 1 −119716 (JP, A) Fukukaihei 4-78561 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01D 5/00-5/62 G01B ⁷ /00-7/34

Claims (18)

(57) [Claims] 1. A magnetic scale comprising a magnetic pattern having a predetermined magnetic field strength distribution composed of a plurality of magnetic field generating means, wherein the magnetic field strength on the magnetic pattern side is regularly different in a predetermined detection direction of a magnetic field strength detecting element. Since it is placed at the position facing the detection element
Of at least two magnetic poles of N pole and S pole which are close to each other in the direction substantially orthogonal to the detection direction and are exposed on the same surface side with the non-magnetic body sandwiched therebetween . A magnetic scale characterized in that a magnetic pole is provided at a predetermined position in the detection direction. 2. The at least one set of magnetic poles is a plurality of sets of magnetic poles arranged in the detection direction, and the plurality of sets of magnetic poles are arranged so that the polarities of the magnetic poles in the same row alternate with each other. 2. The polar arrangement of the two is different.
The magnetic scale shown. 3. The at least one set of magnetic poles is a plurality of sets of magnetic poles arranged in the detection direction, and the plurality of sets of magnetic poles are arranged such that the polarities of the magnetic poles in the same row change in a predetermined order. 2. The magnetic scale according to claim 1, wherein the magnetic poles are arranged in different polarities. 4. The plurality of sets of magnetic poles or at least two magnetic poles of N pole and S pole arranged in the same row include magnetic poles having different lengths in the detection direction, and an exposed surface of the magnetic poles in the detection direction. The magnetic scale according to claim 1, wherein the magnetic scale is located at different heights according to the length of the exposed surface. 5. A plurality of sets of magnetic poles or at least two magnetic poles of N pole and S pole arranged in the same row include magnetic poles having different lengths in the detection direction, and an exposed surface of the magnetic poles in the detection direction. The magnetic scale according to claim 1, wherein the width orthogonal to the detection direction is changed according to the length of the exposed surface. 6. A plurality of magnets are arranged in parallel in a direction orthogonal to the detection direction, and the plurality of sets of magnetic poles are arranged by the number of rows obtained by subtracting 1 from the parallel number of magnets by the facing portions of the plurality of magnets. It comprised, The magnetic scale in any one of Claims 1-5. 7. The magnetic scale according to claim 1, wherein the plurality of sets of magnetic poles are arranged at predetermined angular intervals in a circumferential direction which is the detection direction. 8. A magnetic scale according to any one of claims 1 to 6, a light emitting means for outputting an optical signal, and a surface facing the non-magnetic body on the magnetic pole surface of the magnetic scale.
And a polarization control means for rotating the polarization direction of the optical signal according to the strength of the magnetic field formed by the N and S poles of each set, and the polarization control for transmitting only the polarization in the specific direction. Means, an opto-electric conversion means for converting the light intensity signal after passing through the polarization control means into an electric signal, and an electric signal processing means for processing the electric signal from the photoelectric conversion means to obtain a specific physical quantity according to the signal. And a magnetic detection device. 9. The electric signal processing means determines any one of relative displacement, velocity and acceleration between the magnetic scale and the polarization rotating means based on the electric signal from the photoelectric conversion means. The magnetic detection device according to claim 8, which is characterized in that. 10. A magnetic scale according to claim 7, a light emitting means for outputting an optical signal, and a non-magnetic body facing the magnetic pole surface of the magnetic scale.
And a polarization control means for rotating the polarization direction of the optical signal according to the strength of the magnetic field formed by the N and S poles of each set, and the polarization control for transmitting only the polarization in the specific direction. Means, an opto-electric conversion means for converting the light intensity signal after passing through the polarization control means into an electric signal, and an electric signal processing means for processing the electric signal from the photoelectric conversion means to obtain a specific physical quantity according to the signal. And a magnetic detection device. 11. The electrical signal processing means obtains any one of relative angular displacement, angular velocity and angular acceleration between the magnetic scale and the polarization rotation means based on the electrical signal from the photoelectric conversion means. 11. The method according to claim 10, wherein
The magnetic detection device described. 12. The magnetic scale comprises a plurality of pairs of magnetic poles arranged in parallel in a plurality of rows, and the polarization rotation means is arranged to correspond to the strength of a magnetic field formed by the magnetic poles in each of the plurality of rows. 9. A plurality of polarization rotation elements for rotating the polarization direction of an optical signal, wherein the photoelectric conversion means converts the plurality of light intensity signals after passing through the polarization control means into a plurality of electric signals. , 9, 10 or 11, the magnetic detection device. 13. A magnetic pattern having a predetermined magnetic field intensity distribution comprising a plurality of magnetic field generating means, wherein the magnetic field intensity on the magnetic pattern side is regularly different in a predetermined detection direction, and a non-magnetic body is sandwiched in the detection direction. A magnetic scale in which at least two magnetic poles of an N pole and an S pole which are close to each other and are exposed on the same surface side are arranged in the same row in the detection direction, a light emitting means for outputting an optical signal, and a magnetic pole exposed surface of the magnetic scale. Facing the non-magnetic body on the side
And a polarization control means for rotating the polarization direction of the optical signal according to the strength of the magnetic field formed by the N and S poles of each set, and the polarization control for transmitting only the polarization in the specific direction. Means, an opto-electric conversion means for converting the light intensity signal after passing through the polarization control means into an electric signal, and an electric signal from the photoelectric conversion means, and according to the signal, the magnetic scale and the polarization rotation means An electric signal processing means for determining at least one of relative displacement, velocity, acceleration, angular displacement, angular velocity, and angular acceleration, and a magnetic detection device. 14. The magnetic scale is one in which at least two magnetic poles of an N pole and an S pole arranged in the same row are arranged in parallel in a plurality of rows, and the polarization rotation means is provided in each row of the plurality of rows. A plurality of polarization rotation elements that rotate the polarization direction of the optical signal according to the strength of the magnetic field formed by the magnetic poles, wherein the photoelectric conversion means converts the plurality of light intensity signals after passing through the polarization control means into a plurality of electrical signals. 14. The magnetic detection device according to claim 13, which is converted into a signal. 15. The magnetic scale according to claim 1, and the magnetic scale facing the non-magnetic body on the magnetic pole exposed surface side of the magnetic scale.
A magnetic field strength detecting element, which is provided at a position and which generates a voltage according to the strength of the magnetic field formed by the magnetic poles of the N pole and the S pole of the magnetic scale, and the generated voltage of the magnetic field strength detecting element. And an electric signal processing means for processing the electric signal corresponding to to obtain a specific physical quantity, and a magnetic detection device. 16. The electric signal processing means obtains any one of relative displacement, velocity and acceleration between the magnetic scale and the magnetic field strength detecting element based on the electric signal. Item 15. The magnetic detection device according to Item 15. 17. The magnetic scale according to claim 7, and the non-magnetic body on the magnetic pole exposed surface side of the magnetic scale.
A magnetic field strength detecting element, which is provided at a position and which generates a voltage according to the strength of the magnetic field formed by the magnetic poles of the N pole and the S pole of the magnetic scale, and the generated voltage of the magnetic field strength detecting element. And an electric signal processing means for processing the electric signal corresponding to to obtain a specific physical quantity, and a magnetic detection device. 18. The electrical signal processing means obtains any one of relative angular displacement, angular velocity and angular acceleration between the magnetic scale and the magnetic field strength detection element based on the electrical signal. The magnetic detection device according to claim 17.