JP2013160734A - Position sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a position sensor allowing its downsizing.SOLUTION: A rotary encoder 8 includes: a stator 9 having an exciting coil 17 having a planar shape and a detection coil 16; and a rotor 10 which is disposed to face to the stator 9 and in which magnetically different regions are periodically arranged in a movement direction. The detection coil 16 has three detection coil pattern. A first detection coil pattern 16a and a second detection coil pattern 16b, and the second detection coil pattern 16b and a third detection coil pattern 16c are arranged in such a manner as to provide a phase difference of 90 degree therebetween. A difference between an output signal from the first detection coil pattern 16a and an output signal from the second detection coil pattern 16b, and a difference between the output signal from the second detection coil pattern 16b and an output signal from the third detection coil pattern 16c are used to form a pulse signal S13 and a pulse signal S14 which are two-phase signals with a phase difference of 90 degree therebetween.

Description

  The present invention is used to detect an operating position of a mover, and can operate while facing a stator fixing plate on which a stator coil is formed and a stator fixing plate through a gap. The present invention relates to a position sensor having a movable element provided.

  Conventionally, as this type of technology, for example, a rotation angle sensor widely used in each field can be cited. A crank angle sensor, which is one of rotation angle sensors, is employed in an engine mounted on an automobile in order to detect its rotation speed and rotation phase.

  Patent Document 1 discloses a technique related to a position detection sensor of a linear pulse motor. An excitation coil and a detection coil are arranged on the mover so as to detect a positional variation with respect to a stator formed of a comb-like magnetic body. This is a position sensor that detects the position of the mover by fluctuation in output from the detection coil.

  Patent Document 2 discloses a technique related to a resolver. This is a phase difference type resolver, which has an excitation coil to which an excitation signal is input and a detection coil to be detected by a detection signal, and is based on a detection signal that is displaced according to the displacement amount of a passive body provided with the excitation coil or the detection coil. A resolver that detects the amount of displacement employs a method in which a detection signal is obtained by demodulating a modulation signal obtained by modulating a high-frequency signal with an excitation signal in an excitation coil.

  Patent Document 3 discloses a technique related to a rotation angle detection sensor. A rotating body, and a conductor pattern rotatably attached together with the rotating body, the encoder structure having a periodically changing width dimension of the conductor pattern, and a plurality of inductance elements. A rotation angle detection sensor is configured from the sensor body that is disposed opposite to the sensor body.

  Patent Document 4 discloses a technique related to a rotation angle detection sensor system and a position detection method for a movable part. In order to detect the position of the rotating body of the machine, it has an encoder structure attached to the rotating body and movable together with the rotating body. The encoder structure is, for example, a metal body having an edge that draws a sine curve. A sensor assembly for supplying a sensor signal for supplying at least one sensor signal capable of determining a position is provided on the opposite side of the encoder structure. The sensor assembly includes a first inductance element. The rotational angle detection sensor system is configured such that the inductance element causes a change in inductance depending on the operation of the encoder structure.

JP-A-61-226613 JP 2000-292205 A JP 2009-128312 A JP 2007-327940 A

  However, using the techniques of Patent Documents 1 to 4 for position sensors has the following problems.

  The position sensor is required to be downsized and highly accurate especially when mounted on the vehicle. However, as clearly shown in Patent Document 3 and Patent Document 4, there are many cases in which four coils are used as the detection coil. This is because two sets of detection coils with a phase difference of 180 degrees are arranged on the stator with a 90-degree phase difference, and an output signal having a 90-degree phase difference is detected by taking the difference between the two, It is because it is detected. However, since this method requires a total of four detection coils, the width of the detection coil becomes wide. In this regard, Patent Document 1 and Patent Document 2 are not referred to.

  Accordingly, an object of the present invention is to provide a position sensor capable of reducing the size of the position sensor in order to solve such a problem.

In order to achieve the above object, the position sensor according to the present invention has the following characteristics.
(1) A stator having an excitation coil and a detection coil formed in a planar shape, and a mover that is arranged opposite to the stator and in which regions having different magnetic properties are periodically arranged in the movement direction. In the position sensor, the detection coil includes a first detection coil pattern, a second detection coil pattern, and a third detection coil pattern, and the first detection coil pattern, the second detection coil pattern, and the second detection coil pattern. The coil pattern and the third detection coil pattern are arranged with a phase difference of 90 degrees, respectively, and the output signal from the first detection coil pattern and the second detection obtained by exciting the excitation coil The difference between the output signal from the coil pattern and the difference between the output signal from the second detection coil pattern and the output signal from the third detection coil pattern Used, characterized in that the 2-phase signal of the phase difference of 90 degrees is formed.

(2) In the position sensor according to (1), output signals from the first detection coil pattern, the second detection coil pattern, and the third detection coil pattern are respectively envelope detected, and the envelope detection is performed. The output signal is input to a differential amplifier and the difference is calculated to form the two-phase signal.

(3) In the position sensor according to (1) or (2), the mover is a columnar rotating body, and a region having a different magnetic property is provided on the outer peripheral surface in the radial direction of the rotating body. Periodically arranged in the rotational direction, a magnetic region for Z phase is provided on the axial surface of the rotating body, and the stator faces the radially outer peripheral surface of the rotating body, Fourth detection for detecting the magnetic region for the Z phase, wherein the first detection coil pattern, the second detection coil pattern, and the third detection coil pattern are arranged and face the surface in the axial direction of the rotating body. A coil pattern is arranged.

(4) In the position sensor according to (1) or (2), the mover moves on the mover base made of a nonmagnetic metal on a nonmagnetic metal movable region where the magnetic permeability is different from that of the nonmagnetic metal. The regions having different magnetic permeability are arranged in a direction, and are configured by a plurality of patterns, and a part of the plurality of patterns is different from the other patterns for Z signal detection. And forming as a trigger region.

  With the position sensor according to the present invention having such characteristics, the following operations and effects can be obtained.

  First, in the invention described in (1), a stator having an excitation coil and a detection coil formed in a planar shape, and an area that is opposed to the stator and that has different magnetic characteristics are periodically arranged in the moving direction. In the position sensor having the movable element, the detection coil includes a first detection coil pattern, a second detection coil pattern, and a third detection coil pattern, and the first detection coil pattern and the second detection coil pattern, The second detection coil pattern and the third detection coil pattern are arranged with a phase difference of 90 degrees, respectively, and the output signal from the first detection coil pattern and the second detection coil obtained by exciting the excitation coil 90 degree phase difference using difference between output signal from pattern and difference between output signal from second detection coil pattern and output signal from third detection coil pattern In which two-phase signals are formed.

  As a result, the position sensor can be downsized. This is because the detection coil is composed of three coil patterns of a first detection coil pattern, a second detection coil pattern, and a third detection coil pattern, so that four coils as shown in Patent Document 3 and Patent Document 4 are used. Compared to the method using, the size can be simply reduced to 3/4 and the size can be reduced. Even when three coils are used, the first detection coil pattern and the second detection coil pattern, and the second detection coil pattern and the third detection coil pattern are arranged with a phase difference of 90 degrees, respectively. 90 degree phase difference using the difference between the output signal from the pattern and the output signal from the second detection coil pattern, and the difference between the output signal from the second detection coil pattern and the output signal from the third detection coil pattern Therefore, the position detection function of the position sensor is not impaired.

  Next, in the aspect described in (2), in the position sensor described in (1), the output signals from the first detection coil pattern, the second detection coil pattern, and the third detection coil pattern are respectively envelope-detected. The output signal subjected to the envelope detection is input to the differential amplifier, and the difference is calculated to form a two-phase signal. Therefore, the position detection signal can be formed with a simple circuit configuration, and the cost can be reduced.

  Next, in the aspect described in (3), in the position sensor described in (1) or (2), the mover is a columnar rotating body, and has different magnetic characteristics on the radially outer circumferential surface of the rotating body. The region is periodically arranged with respect to the rotating direction of the rotating body, a magnetic region for the Z phase is provided on the axial surface of the rotating body, and the stator is opposed to the radially outer peripheral surface of the rotating body, A first detection coil pattern, a second detection coil pattern, and a third detection coil pattern are arranged, and a fourth detection coil pattern that detects a magnetic region for the Z phase is arranged opposite to the axial surface of the rotating body. It is what is done. Using the Z-phase signal as a trigger, the absolute position can be detected from the output on the detection coil side, which contributes to improving the accuracy of the position sensor. In addition, since the Z-phase magnetic body region is provided on the axial surface of the rotating body, the position sensor can be downsized.

  Further, in the aspect described in (4), in the position sensor described in (1) or (2), the mover is a region on the nonmagnetic metal mover base having a permeability different from that of the nonmagnetic metal. Are periodically arranged in the moving direction of the mover, and regions having different magnetic permeability are composed of a plurality of patterns, and a part of the plurality of patterns has a different Z permeability from the other patterns. By forming as a trigger region for detection, the trigger region is detected and a Z signal is obtained. Here, a part of the plurality of patterns means one region having different magnetic permeability, and at least one of the regions having different magnetic permeability is used as a trigger for Z signal detection. As a result, it becomes possible to detect the absolute position from the output on the detection coil side using the signal for the Z phase as a trigger, which contributes to improving the accuracy of the position sensor. In addition, there is no need to provide a Z-phase pattern separately from the A-phase and B-phase patterns, and the position sensor can be downsized.

It is a typical perspective view about the structure of the rotary encoder of 1st Embodiment. It is a perspective view which shows the structure of the stator of 1st Embodiment. It is a schematic diagram about the correspondence of a detection coil, an excitation coil, and a rotor pattern of 1st Embodiment. It is a schematic cross section about the composition of the flexible printed circuit board and back yoke of a 1st embodiment. It is the model perspective view shown about the structure of the back yoke of 1st Embodiment. It is a detection block diagram of a rotary encoder of a 1st embodiment. The output waveform of 1st Embodiment is put together on the graph. (A) It is a schematic diagram about the positional relationship of a rotor and a stator of 1st Embodiment. (B) It is a graph which shows the output waveform in (a) of 1st Embodiment. (A) It is a schematic diagram about the positional relationship of a rotor and a stator of 1st Embodiment. (B) It is a graph which shows the output waveform in (a) of 1st Embodiment. (A) It is a schematic diagram about the positional relationship of a rotor and a stator of 1st Embodiment. (B) It is a graph which shows the output waveform in (a) of 1st Embodiment. (A) It is a schematic diagram about the positional relationship of a rotor and a stator of 1st Embodiment. (B) It is a graph which shows the output waveform in (a) of 1st Embodiment. It is an equivalent circuit diagram regarding the exciting coil and the detection coil of the first embodiment. (A) It is a model front view about the structure of the rotary encoder of 2nd Embodiment. (B) It is a model side view about the structure of the rotary encoder of 2nd Embodiment. It is a detection block diagram of the rotary encoder of 2nd Embodiment. It is a side view which shows the structure which provided the pattern for Z signal detection prepared for the comparison in the side surface (outer peripheral surface) of the rotary encoder. It is a graph which shows the relationship of the pulse signal of 2nd Embodiment. (A) It is a schematic diagram shown about the positional relationship of a rotor and a stator of 3rd Embodiment. (B) It is a graph which shows the output waveform in (a) of 3rd Embodiment. It is a detection block diagram of the rotary encoder of 3rd Embodiment.

  Next, a first embodiment of the present invention will be described with reference to the drawings using a specific example used in a rotary encoder for detecting a rotation angle prepared for a crankshaft of an automobile.

  FIG. 1 is a schematic perspective view showing the configuration of the rotary encoder 8. A rotary encoder 8 which is a kind of position sensor includes a rotor 10 serving as a mover attached to a rotating shaft (not shown) and a stator 9 serving as a stator fixed to a part of the outer periphery of the rotor 10. . Since the rotor 10 is preferably made of a non-magnetic conductive metal, a cylindrical body having an outer diameter of 80 mm and a width of 10 mm using non-magnetic stainless steel is used in the present embodiment. Since the material may be any non-magnetic and conductive metal, for example, aluminum or the like can be used.

  FIG. 2 is a perspective view showing the configuration of the stator 9. FIG. 3 is a schematic diagram showing the correspondence between the detection coil 16, the excitation coil 17, and the rotor pattern 13. FIG. 5 is a schematic perspective view showing the configuration of the flexible printed circuit board 23 and the back yoke 15. The rotor pattern 13 is formed on the outer peripheral surface of the rotor 10. The detection coil 16 and the excitation coil 17 are also drawn on a plane so that the correspondence can be understood. In the configuration of the rotor 10, nonmagnetic metals forming nonmagnetic conductive regions and magnetic materials using ferrite or the like are alternately arranged. The magnetic body 11 is formed by applying a mixture of a magnetic powder such as ferrite and a resin binder to the outer peripheral surface of the rotor 10 by screen printing. On the other hand, the nonmagnetic part 12 which is a nonmagnetic conductive region is a bare metal part of the rotor 10 to which the magnetic part 11 is not applied. That is, the magnetic body portion 11 is formed with a predetermined width at predetermined intervals, whereby the rotor pattern 13 is formed as a stripe pattern on the outer peripheral surface of the rotor 10.

  As shown in FIG. 2, the stator 9 has a stator body 26 in which a flange-like attachment member 24 is fixed. A circuit portion 25 is attached to the upper surface of the stator body 26. In addition, although the circuit part 25 has a structure which is covered with a molding material and cannot be seen from the outside as a product, the molding material is omitted in FIG. 2 for illustration. A flexible printed circuit board 23 is provided on the front end surface of the stator body 26. A detection coil 16 and an excitation coil 17 are provided on the surface of the flexible printed circuit board 23. Further, the back yoke 15 shown in FIG. 5 is coated with a magnetic powder mixed with a resin binder like the magnetic part 11, and is provided under the detection coil 16 via a PI film (polyimide film) 30. The back yoke 15 is provided with a width sufficient to cover the exciting coil 17. In FIG. 2, the coil pattern of the exciting coil 17 appears.

  A detection coil 16 and an excitation coil 17 are formed on each side of the flexible printed circuit board 23 of the stator 9. FIG. 4 shows a schematic cross-sectional view of the configuration of the flexible printed circuit board 23 and the back yoke 15. The flexible printed circuit board 23 is provided with a detection coil 16 and an excitation coil 17 which are laminated. In FIG. 4, the excitation coil 17 is formed on the upper surface of the flexible printed circuit board 23, and is laminated with a PI film 30 thereon. The detection coil 16 is formed on the lower surface of the flexible printed circuit board 23 and laminated with a PI film 30. The back yoke 15 is laminated with a PI film 30. Therefore, the back yoke 15, the detection coil 16, and the stator body 26 are separated from each other by the PI film 30. In FIG. 4, a gap is provided between the PI film 30 and the stator main body 26 for the sake of explanation.

  As shown in FIG. 3, the detection coil 16 has a first detection coil pattern 16a, a second detection coil pattern 16b, and a third detection coil pattern 16c. The first detection coil pattern 16a, the second detection coil pattern 16b, and the third detection coil pattern 16c are arranged at equal intervals, and are composed of printed coils wound in the same direction in the clockwise direction as shown in FIG. The arrangement interval of the detection coils 16 is set as the distance between the centers of the coil patterns of the detection coil 16 by 2.5 times the width of the magnetic body portion 11 of the rotor pattern 13.

  The exciting coil 17 has a first exciting coil pattern 17a, a second exciting coil pattern 17b, a third exciting coil pattern 17c, and a fourth exciting coil pattern 17d. The first excitation coil pattern 17a and the third excitation coil pattern 17c are formed of a coil pattern formed by winding counterclockwise, and the second excitation coil pattern 17b and the fourth excitation coil pattern 17d are formed by winding clockwise. Therefore, the excitation coil 17 is composed of coil patterns having different coil turn directions.

  Further, the winding end of the first excitation coil pattern 17a and the winding start of the second excitation coil pattern 17b are connected by the connecting portion 17ab. The end of winding of the second excitation coil pattern 17b and the start of winding of the third excitation coil pattern 17c are connected by a connecting portion 17bc. The winding end of the third excitation coil pattern 17c and the winding start of the fourth excitation coil pattern 17d are connected by a connection portion 17cd. The first excitation coil pattern 17a to the fourth excitation coil pattern 17d are arranged at equal intervals. The arrangement interval follows the detection coil 16.

  Next, the positional relationship between the detection coil 16 and the excitation coil 17 will be described. The first detection coil pattern 16a is formed between the first excitation coil pattern 17a and the second excitation coil pattern 17b, and the first detection coil pattern 16a is formed on one side of the first excitation coil pattern 17a and one side of the second excitation coil pattern 17b. The coil patterns of the 1 detection coil pattern 16a are configured to overlap each other.

  The second detection coil pattern 16b is formed between the second excitation coil pattern 17b and the third excitation coil pattern 17c, and the second detection coil pattern 16b is formed on one side of the second excitation coil pattern 17b and one side of the third excitation coil pattern 17c. The two detection coil patterns 16b are configured such that the wirings of the coil patterns overlap each other.

  The third detection coil pattern 16c is formed between the third excitation coil pattern 17c and the fourth excitation coil pattern 17d. The third detection coil pattern 16c is formed on one side of the third excitation coil pattern 17c and one side of the fourth excitation coil pattern 17d. The three detection coil patterns 16c are configured such that the wirings of the coil patterns overlap each other.

  That is, the detection coil 16 is configured such that a part of the wiring overlaps the coil pattern of the excitation coil 17. As shown in FIG. 3, the first excitation coil pattern 17a and the third excitation coil pattern 17c are designed so that the current flows in the same direction at the portion where the detection coil 16 and the wiring overlap. Further, the second excitation coil pattern 17b and the fourth excitation coil pattern 17d are designed such that current flows in the opposite direction at the portion where the detection coil 16 and the wiring overlap.

  FIG. 6 shows a detection block diagram of the rotary encoder 8. A high frequency sine wave of about 2 MHz is input to the exciting coil 17. As a result, the number of windings of the exciting coil 17 can be reduced. The terminal of the first detection coil pattern 16 a is connected to the differential amplifier 31 and inputs the signal S 1 to the differential amplifier 31. The differential amplifier 31 differentially amplifies the signal S1 to obtain a signal S5. The terminal of the second detection coil pattern 16b is connected to the differential amplifier 32 and inputs the signal S2 to the differential amplifier 32. The terminal of the third detection coil pattern 16 c is connected to the differential amplifier 33 and inputs the signal S 3 to the differential amplifier 33. The differential amplifier 32 obtains a signal S6 from the differential amplifier 32 and a signal S7 from the differential amplifier 33.

  Next, the envelope detection of the outer envelope of the high-frequency signal S5 obtained from the differential amplifier 31 is performed by the envelope detector 41 to obtain a signal S8. Similarly, the high-frequency signal S6 obtained from the differential amplifier 32 and the high-frequency signal S7 obtained from the differential amplifier 33 are input to the envelope detector 42 and the envelope detector 43, respectively, and the signal S9 and the signal S10 are obtained. obtain. The high frequency signal S9 of the envelope detector 42 is 90 degrees out of phase with the high frequency signal S8 of the envelope detector 41. The high frequency signal S10 of the envelope detector 43 is 180 degrees out of phase with the high frequency signal S8 of the envelope detector 41. As shown in FIG. 3, the second detection coil pattern 16b is arranged with a half cycle shift with respect to the first detection coil pattern 16a, and the third detection coil pattern 16c is arranged with a half cycle shift. Because.

  The output waveform S8 of the envelope detector 41 and the output waveform S9 of the envelope detector 42 are input to the differential amplifier 34, and both are differentially amplified to obtain a signal S11. The signal S11 is input to the comparator 51 to obtain the pulse signal S13. The output waveform S9 of the envelope detector 42 and the output waveform S10 of the envelope detector 43 are input to the differential amplifier 35, and both are differentially amplified to obtain a signal S12. The signal S12 is input to the comparator 52 to obtain the pulse signal S14. The rotation angle of the rotor 10 relative to the stator 9 can be calculated using the pulse signal S13 and the pulse signal S14.

  FIG. 7 shows a summary of waveforms in one graph. The signal S8 shows the waveform of Sinθ, the signal S9 shows the waveform of Sin (θ + 90), and the signal S10 shows the waveform of Sin (θ + 180). The signal S11 obtained by taking the difference between the signal S9 and the signal S8 by the differential amplifier 34 becomes Sin (θ + 90) −Sinθ, and a waveform with a phase shift of 225 degrees can be obtained. On the other hand, the signal S12 obtained by taking the difference between the signal S10 and the signal S9 by the differential amplifier 35 becomes Sin (θ + 180) −Sin (θ + 90), and a waveform with a phase shift of 135 degrees can be obtained.

  FIG. 8A shows the positional relationship between the rotor 10 and the stator 9. FIG. 8B shows the output waveform S in FIG. FIG. 9A shows the positional relationship between the rotor 10 and the stator 9. FIG. 9B shows the output waveform S in FIG. FIG. 10A shows the positional relationship between the rotor 10 and the stator 9. FIG. 10B shows the output waveform S in FIG. FIG. 11A shows the positional relationship between the rotor 10 and the stator 9. FIG. 11B shows the output waveform S in FIG. FIG. 12 shows an equivalent circuit regarding the excitation coil and the detection coil. From FIG. 8 to FIG. 11, the rotor 10 is advanced and the rotor pattern 13 is moving. Along with this, the state of the output waveform S obtained by the detection coil 16 changes. For the sake of explanation, the magnetic body part 11 and the non-magnetic body part 12 of the rotor pattern 13 are given reference numerals indicating positions from a to h. The correspondence relationship between the detection coil 16 and the excitation coil 17 will be described with reference to FIG.

  The equivalent circuit 100 is a circuit configured to show a current generated when the first detection coil pattern 16a overlaps the first excitation coil pattern 17a and the second excitation coil pattern 17b as shown in FIG. The first coupling portion C1 is formed such that the first excitation coil right side 17ar and the first detection coil left side 16al face each other. The second coupling portion C2 is formed such that the second excitation coil left side 17bl and the first detection coil right side 16ar face each other. The third coupling portion C3 is formed such that the circuit short side 16a1 and the connection portion 17ab face each other. Therefore, when an AC signal is input to the excitation coil 17, the first coupling portion C1 and the second coupling portion C2 are connected to generate an electromotive force in the opposite direction in the first detection coil pattern 16a. The part C1 and the third coupling part C3 are connected so as to generate an electromotive force in the same direction. That is, if the electromotive force at the first coupling unit C1 is the electromotive force V1, the electromotive force at the second coupling unit C2 is the electromotive force V2, and the electromotive force at the third coupling unit C3 is the electromotive force V3, the first detection coil The output V4 of the pattern 16a is (electromotive force V1) − (electromotive force V2) + (electromotive force V3).

  Specifically, first, in the state of FIG. 8A, the first excitation coil right side 17ar overlaps the magnetic body portion 11c. When a high-frequency sine wave signal is input to the excitation coil 17 in this state, a magnetic flux is generated. Magnetic flux generated at the right side 17ar of the first excitation coil passes through the magnetic part 11c. A large electromotive force is generated on the left side 16al of the first detection coil due to a change in the passing magnetic flux. The second excitation coil left side 17bl overlaps the nonmagnetic part 12c. Therefore, the magnetic flux generated in the second excitation coil left side 17bl passes through the non-magnetic part 12c. In the non-magnetic body portion 12c, an eddy current is generated in a direction that cancels the change in the magnetic flux, so that the electromotive force generated in the first detection coil right side 16ar of the detection coil 16 is reduced. Considering the equivalent circuit 100 shown in FIG. 12, the electromotive force V1 generated in the first coupling portion C1 including the first excitation coil right side 17ar and the first detection coil left side 16al increases through the magnetic body portion 11c, The electromotive force V2 generated in the second coupling portion C2 including the second excitation coil left side 17bl and the first detection coil right side 16ar is small because it passes through the non-magnetic body portion 12c. Therefore, an electromotive force indicated by the difference between the electromotive force V1 and the electromotive force V2 is generated in the equivalent circuit 100, and the amplitude Am1 is maximized. The electromotive force V3 of the third coupling part C3 is added thereto, and a waveform Sa offset from the reference voltage by the offset width Of as shown in FIG. 8B is obtained. The short circuit side 16a1 and the connecting portion 17ab are arranged so as not to directly overlap.

  Next, in the state of FIG. 9A, the rotor pattern 13 is moved by rotation, and the first excitation coil right side 17ar is located at the boundary between the magnetic part 11c and the nonmagnetic part 12b. The second excitation coil left side 17bl is located at the boundary between the magnetic part 11c and the non-magnetic part 12c. Considering the equivalent circuit 100 shown in FIG. 12, the electromotive force V1 generated in the first coupling portion C1 and the electromotive force V2 generated in the second coupling portion C2 are the nonmagnetic body portion 12b, the magnetic body portion 11c, and the nonmagnetic portion. It becomes equal in the relationship of the part which overlaps with the body part 12c. Accordingly, in the equivalent circuit 100, the electromotive force indicated by the difference between the electromotive force V1 and the electromotive force V2 is 0, but the electromotive force V3 is added. Therefore, only the offset width Of from the reference voltage as shown in FIG. A waveform Sb having an offset amplitude Am2 is obtained. The amplitude Am2 is smaller than the amplitude Am1.

  Next, in the state of FIG. 10A, the rotor pattern 13 is further moved by rotation, and the first excitation coil right side 17ar overlaps with the non-magnetic part 12b. On the other hand, the second excitation coil left side 17bl overlaps the magnetic part 11c. Considering the equivalent circuit 100 shown in FIG. 12, the electromotive force V1 generated in the first coupling portion C1 is reduced by overlapping with the nonmagnetic body portion 12b, and the electromotive force V2 generated in the second coupling portion C2 is It overlaps with the part 11c and becomes large. Therefore, in the equivalent circuit 100, the electromotive force indicated by the difference between the electromotive force V1 and the electromotive force V2 is negative, but since the electromotive force V3 is added, the offset width Of of the reference voltage as shown in FIG. A waveform Sc having an amplitude Am3 that is offset by an amount of is obtained. The amplitude Am3 is minimum. At this time, the magnitude of the coupling of the third coupling portion C3 is adjusted so that the output V4 does not become negative. Specifically, it is adjusted according to the distance between the circuit short side 16a1 and the connecting portion 17ab and the length of each.

  Next, in the state of FIG. 11A, the rotor pattern 13 further moves by rotating, and the first excitation coil right side 17ar is located at the boundary between the magnetic body portion 11b and the nonmagnetic body portion 12b. On the other hand, the second excitation coil left side 17bl is located at the boundary between the magnetic part 11c and the non-magnetic part 12b. Considering the equivalent circuit 100 shown in FIG. 12, the electromotive force V1 generated in the first coupling portion C1 and the electromotive force V2 generated in the second coupling portion C2 are the nonmagnetic body portion 12b, the magnetic body portion 11c, and the nonmagnetic portion. It becomes equal in the relationship of the part which overlaps with the body part 12c. Accordingly, in the equivalent circuit 100, the electromotive force indicated by the difference between the electromotive force V1 and the electromotive force V2 is 0, but the electromotive force V3 is added. Therefore, the offset width Of is greater than the reference voltage as shown in FIG. A waveform Sb having an offset amplitude Am2 is obtained.

  Although the first detection coil pattern 16a has been described, the corresponding second excitation coil pattern 17b, third excitation coil pattern 17c, and fourth excitation coil are similarly applied to the second detection coil pattern 16b and the third detection coil pattern 16c. An output waveform is obtained by the relationship between the coil pattern 17 d and the magnetic body portion 11 and the non-magnetic body portion 12. However, the first detection coil pattern 16a is as shown by the relationship between the output waveform S8, the output waveform S9, and the output waveform S10 shown in FIG. This is because the distance from the first detection coil pattern 16 a is arranged at a pitch 2.5 times the pitch of the magnetic body portion 11. In addition, the circuit short side 16b1 and connection part 17bc of the 2nd detection coil pattern 16b, and the circuit short side 16c1 and connection part 17cd of the 3rd detection coil pattern 16c act, and a 3rd detection coil also acts on the 2nd detection coil pattern 16b. Similarly to the first detection coil pattern 16a, an offset effect can be obtained for the pattern 16c.

  As described above, the electromotive force waveform detected by the detection coil 16 is obtained as the output waveform S8, the output waveform S9, and the output waveform S10 by the movement of the rotor pattern 13, and will be described with reference to the block diagram of FIG. The pulse signal S13 is obtained as the A signal, and the pulse signal S14 is obtained as the B signal. As described above, these signals are a 225-degree phase shift signal and a 135-degree phase shift signal. The position of the rotor 10 can be detected by the stator 9 using these signals.

  Since the position sensor according to the first embodiment has the configuration described above, the following effects and advantages are achieved.

  First, an advantage is that the position sensor can be miniaturized. The configuration of the rotary encoder 8 according to the first embodiment is such that a stator 9 having an excitation coil 17 and a detection coil 16 formed in a planar shape is arranged opposite to the stator 9, and regions having different magnetism are periodically arranged in the movement direction. In the rotary encoder 8 having the rotor 10 disposed in the position, the detection coil 16 includes a first detection coil pattern 16a, a second detection coil pattern 16b, and a third detection coil pattern 16c.

  Thus, the detection coil 16 has three coil patterns, and the first detection coil pattern 16a and the second detection coil pattern 16b, and the second detection coil pattern 16b and the third detection coil pattern 16c each have a phase difference of 90 degrees. And the difference between the output signal from the first detection coil pattern 16a and the output signal from the second detection coil pattern 16b, which is obtained by exciting the excitation coil 17, and from the second detection coil pattern 16b. The pulse signal S13 and the pulse signal S14, which are two-phase signals having a phase difference of 90 degrees, are formed using the difference between the output signal of the second detection coil pattern and the output signal from the third detection coil pattern 16c. Therefore, as compared with the case where four detection coils are used as in Patent Document 3 and Patent Document 4, the size can be simply reduced to 3/4 and the size can be reduced. Moreover, it is possible to contribute to cost reduction by reducing the number of detection coils.

  Further, the position detection signal can be detected with a simple circuit configuration, and the cost can be reduced. This is because each of the output signals from the first detection coil pattern 16a, the second detection coil pattern 16b, and the third detection coil pattern 16c is envelope-detected, and the output signal subjected to the envelope detection is input to the differential amplifier. The difference is calculated and a two-phase signal is formed. Specifically, the circuit configuration is simple as shown in FIG. What is used for the circuit is one that can be configured relatively inexpensively, such as the envelope detector 41 and the differential amplifier 31, and the configuration itself is simple. As a result, the cost of the rotary encoder 8 can be reduced.

  Moreover, the point which can provide the rotary encoder 8 which is a position sensor which can enlarge an amplitude ratio is mentioned as an effect. The configuration of the rotary encoder 8 according to the first embodiment includes a stator 9 having an excitation coil 17 and a detection coil 16 formed in a planar shape, a face facing the stator 9, and a magnetic body portion 11 and a non-magnetic body portion 12. In the rotary encoder 8 having the rotors 10 alternately arranged in the moving direction, the first excitation coil pattern 17a of the excitation coil 17 and the second excitation coil pattern 17b formed adjacent to the rotor 10 The first detection coil pattern 16a of the detection coil 16 is arranged so as to be sandwiched in the moving direction. The second excitation coil pattern 17b is wound around the first excitation coil pattern 17a so that the excitation current flows in the opposite direction.

  As a result, the detection accuracy of the rotary encoder 8 can be improved. This is because of the following reasons. In other words, the first detection coil pattern 16 a is provided between the first excitation coil pattern 17 a and the second excitation coil pattern 17 b so as to be sandwiched in the rotation direction of the rotor 10. Similarly, the second detection coil pattern 16b is sandwiched between the second excitation coil pattern 17b and the third excitation coil pattern 17c, and the third detection coil is sandwiched between the third excitation coil pattern 17c and the fourth excitation coil pattern 17d. The pattern 16c is provided between the patterns 16c.

  The first excitation coil pattern 17a and the second excitation coil pattern 17b, the second excitation coil pattern 17b and the third excitation coil pattern 17c, and the third excitation coil pattern 17c and the fourth excitation coil pattern 17d are shown in FIG. Thus, adjacent coil patterns are wound in the opposite direction. For this reason, when exemplified by the excitation coil 17, the magnetic flux density passing through the magnetic body portion 11 continuously changes due to the movement of the rotor 10. For example, in the first detection coil pattern 16 a, the first excitation coil pattern 17 a is The direction of the magnetic flux is opposite between the generated magnetic flux and the magnetic flux generated by the second excitation coil pattern 17b. For this reason, the first detection coil pattern in the case where the influence of the first excitation coil pattern 17a is dominant and the case where the influence of the second excitation coil pattern 17b is dominant in the magnetic flux passing through the magnetic body portion 11. The difference in electromotive force generated in the circuit 16a becomes large, and it becomes possible to take a large amplitude ratio as shown by the waveform Sa in FIG.

  Another advantage is that the S / N ratio of the rotary encoder 8 can be improved. This is because the wirings on the sides facing each other of the first excitation coil pattern 17a and the second excitation coil pattern 17b overlap with a part of the wiring of the first detection coil pattern 16a via the insulating layer. Has been placed. For this reason, the distance between the detection coil 16 and the excitation coil 17 can be minimized. Since the strength of the electric field becomes weaker in inverse proportion to the distance around the wiring, the condition deteriorates if the distance between the excitation coil 17 and the detection coil 16 increases, but the distance between the detection coil 16 and the excitation coil 17 should be reduced. Thus, the output of the current detected by the detection coil 16 is increased, and as a result, the S / N ratio of the position coil can be improved.

  Another advantage is that the circuit configuration can be simplified by the offset effect. The first excitation coil pattern 17a and the second excitation coil pattern 17b are connected by a connection portion 17ab, and the second excitation coil pattern 17b and the third excitation coil pattern 17c are connected by a connection portion 17bc and the third excitation coil pattern 17c. The fourth excitation coil pattern 17d is connected by a connecting portion 17cd. In the first detection coil pattern 16a to the third detection coil pattern 16c corresponding thereto, the short sides of the respective coil patterns overlap with the connection portions 17ab to 17cd, respectively.

  For this reason, by supplying electric power to the excitation coil 17, magnetic flux is also generated by the electric power passing through the connection portion 17ab to the connection portion 17cd, the magnetic flux density is increased in the magnetic body portion 11, and the electromotive force is generated in the detection coil 16. As a result, the output waveform S is offset. The electromotive force V3 described in the equivalent circuit 100 of FIG. 12 is offset by adding the electromotive force V3 to the difference between the electromotive force V1 and the electromotive force V2, thereby obtaining an output V4. As a result, waveforms such as the waveforms Sa to Sc as shown in FIGS. 8B to 11B are obtained. The waveform Sc is a state where the amplitude of the output waveform S detected by the detection coil 16 is the lowest. Although this waveform Sc shows a waveform having the same cycle as the waveform Sa, the waveform is inverted if there is no offset effect.

  However, because the waveform Sa and the waveform Sc have the same cycle due to the offset effect, the waveforms of the pulse signal S13 and the pulse signal S14 can be obtained by comparing the waveforms without the need for a correction circuit. Therefore, the cost of the rotary encoder 8 can be reduced.

  Moreover, the point which can improve the detection accuracy of a position sensor by providing the back yoke 15 as an effect is mentioned. The excitation coil 17, the detection coil 16, and the back yoke 15 are separated from each other by the PI film 30, and are laminated as shown in FIG. The PI film 30 also has a function of holding the back yoke 15 formed of a magnetic material on the flexible printed circuit board 23. The magnetic flux generated by the exciting coil 17 passes through a magnetic material such as the magnetic body portion 11 so that the effect of increasing the magnetic flux density can be obtained. As a result, the detection accuracy of the rotary encoder 8 can be improved.

  Further, since the back yoke 15 can be prevented from being peeled off by being suppressed by the PI film 30, it is possible to reduce the amount of binder mixed in the magnetic material used for the back yoke 15. The binder has a function of holding the magnetic material on the flexible printed circuit board 23 without being peeled off, but at the same time causes a decrease in the density of the magnetic material. Therefore, by holding the back yoke 15 using the PI film 30, the amount of binder used for the back yoke 15 can be reduced. As shown in FIGS. 4 and 5, the back yoke 15 is sandwiched between two PI films 30. For this reason, it is possible to hold the back yoke 15 using the PI film 30, and it is possible to increase the thickness of the back yoke 15 as necessary. As a result, the effect of the back yoke 15 increasing the magnetic flux density generated by the exciting coil 17 can be further increased, and the detection accuracy of the rotary encoder 8 is improved.

  Next, as for the second embodiment of the present invention, a specific example using a rotary encoder as in the first embodiment will be described with reference to the drawings.

  In FIG. 13, the schematic diagram is shown about the structure of the rotary encoder 8 of 2nd Embodiment. FIG. 13A is a front view, and FIG. 13B is a side view. The configuration of the rotary encoder 8 of the second embodiment is substantially the same as that of the first embodiment, but the shape of the stator 9 is slightly different. The stator 9 is provided with side ribs 9a as shown in FIG. The side ribs 9 a provided from the stator 9 are overhanged so as to cover a part of the side surface of the rotor 10. As shown in FIG. 13B, the surface of the side rib 9 a facing the rotor 10 corresponds to the Z-phase magnetic body portion 20 which is a Z-phase magnetic region provided on the side surface of the rotor 10. An excitation coil 17e and a Z-phase detection coil 16d are provided. Although not shown in the drawings, the shape of the stator 9 is the same as that shown in FIG. 2, and the shape of the stator body 26 is slightly different.

  Regarding the correspondence between the rotor 10 and the stator 9, the surface of the stator 9 at which the flexible printed circuit board 23 is provided in an arc along the outer peripheral surface of the rotor 10 and the outer peripheral surface of the rotor 10, that is, the rotor pattern 13 are provided. The gap with the surface to be formed is a dimension a. On the other hand, the gap between the side rib 9a and the axial surface of the rotor 10 is a dimension b. The dimension a is about 0.2 mm, and the dimension b is about several mm.

  The magnetic flux generated in the Z-phase excitation coil 17e provided on the side rib 9a by the rotation of the rotor 10 is increased in magnetic flux density by the Z-phase magnetic body portion 20, and detected by the Z-phase detection coil 16d. Since one Z-phase magnetic body portion 20 is provided in the rotor 10, the waveform S is detected by the Z-phase detection coil 16 d only once per rotation of the rotor 10. Therefore, by providing the Z-phase magnetic body portion 20, the signal S detected by the Z-phase detection coil 16d can be used as a trigger.

  FIG. 14 shows a detection block diagram of the rotary encoder. FIG. 14 is obtained by adding a block diagram for detecting a Z-phase signal to the detection block diagram shown in FIG. An output signal S15 is obtained from a terminal 18a connected to the Z-phase detection coil 16d. The output signal S15 is input to the differential amplifier 36 and differentially amplified to obtain a signal S17. The output signal S16 obtained from the terminal 18b connected to the Z-phase detection coil 16d is input to the differential amplifier 37 and differentially amplified to obtain the signal S18.

  The envelope curve of the output signal S17 obtained from the differential amplifier 36 is detected by the envelope detector 44 to obtain the signal S19. The envelope curve of the output signal S18 obtained from the differential amplifier 37 is detected by the envelope detector 45 to obtain a signal S20. The output signal S19 of the envelope detector 44 and the output signal S20 of the envelope detector 45 are input to the differential amplifier 38 to obtain the signal S21, which is input to the comparator 53 to obtain the pulse signal S22. . By using this pulse signal S22 as a trigger, the absolute position can be detected from the output on the detection coil 16 side.

  Since the position sensor according to the second embodiment has the above-described configuration, the following effects and advantages are achieved.

  First, the detection accuracy of the rotary encoder 8 can be improved. This is because the Z-phase magnetic body portion 20 is provided on the axial surface of the rotor 10, which is a rotating body, and the Z-phase detection coil 16 d that detects the Z-phase magnetic body portion 20 faces the Z-phase magnetic body portion 20. By being provided, it is possible to detect the absolute position from the output on the detection coil 16 side using the signal detected by the Z-phase detection coil 16d as a trigger.

  Further, the thickness of the rotary encoder 8 can be suppressed. FIG. 15 shows a configuration in which a Z signal detection pattern is provided on a conventional rotor. In the second embodiment, since the Z-phase magnetic body portion 20 is provided on the axial surface of the rotor 10, the Z-phase magnetic body portion 20 is placed on the outer peripheral surface of the rotor 10 as shown in FIG. Compared to the case where the thickness of the rotor 10 is increased, the thickness of the rotor 10 itself can be reduced. A predetermined interval is required between the rotor pattern 13 and the Z-phase magnetic body portion 20, and both the rotor pattern 13 and the Z-phase magnetic body portion 20 require a certain area. I need. However, the thickness of the rotor 10 can be reduced by moving the portion where the Z-phase magnetic body portion 20 is provided to the side surface of the rotor 10 and the surface in the axial direction.

  In addition, the productivity of the rotary encoder 8 can be improved. Since the side rib 9a is provided on the surface of the rotor 10 in the axial direction, it is necessary to provide the clearance between the side rib 9a and the rotor 10 by the dimension b in consideration of the mounting accuracy. If the dimension b is increased and the clearance is increased, it is not necessary to increase the assembly accuracy of the stator 9 and the rotor 10 more than necessary. However, if the dimension b is set large, the signal detection accuracy in the Z-phase detection coil 16d is deteriorated, and there is a possibility that signal fluctuation occurs.

  FIG. 16 is a graph showing the relationship between the pulse signal S22 and the pulse signal S13. The pulse signal S22 is obtained by processing the waveform detected by the Z-phase detection coil 16d, and the pulse signal S13 is obtained by processing the waveform detected by the first detection coil pattern 16a. As described above, the absolute position of the detection coil 16 can be detected by using the rise T1 of the pulse signal S22 as a trigger. However, if the dimension b shown in FIG. 13 is increased, the influence of the signal delay c of the pulse signal S22 is large. Therefore, the rise T1 varies due to the variation of the dimension b. However, for example, by using the rising edge T2 of the pulse signal S13 next to the rising edge T1 as the trigger, the accuracy of the trigger can be improved. Since there is such a method for improving the accuracy of the trigger, the signal detection accuracy in the Z-phase detection coil 16d is not required to be more severe than necessary, and as a result, the dimension b can be widely used.

  Since the dimension b, which is the clearance between the side rib 9a and the rotor 10, can be widely used, the mounting accuracy of the rotor 10 and the stator 9 in the axial direction of the rotor 10 does not have to be as severe as the dimension a. Due to the structure of the rotor 10, it is difficult to obtain accuracy in the axial direction rather than in the radial direction. Therefore, by adopting such a configuration, the thickness of the rotor 10 can be reduced and it is not necessary to increase the accuracy more than necessary. Therefore, it is possible to improve the assemblability. This leads to an improvement in productivity and can be reflected in cost reduction.

  Next, as for the third embodiment of the present invention, a specific example using a rotary encoder as in the first embodiment will be described with reference to the drawings. The configuration of the rotary encoder 8 of the third embodiment is substantially the same as the configuration of the first embodiment, but the configuration of the rotor 10 is slightly different.

  FIG. 17A shows the positional relationship between the rotor and the stator in the third embodiment. FIG. 17B shows the output waveform. The rotor 10 used in the third embodiment has substantially the same configuration as that of the first embodiment, but at least one of the magnetic body portions 11 corresponding to the high magnetic permeability region formed on the outer peripheral surface of the rotor 10 is provided. Materials having different magnetic permeability are used, and a Z signal magnetic body portion 11d serving as a trigger region is formed. As a method of changing the magnetic permeability, a method of using a different kind of magnetic material or changing the particle size of the magnetic material or the mixing ratio with the resin binder can be considered. Here, it is assumed that the Z signal magnetic body portion 11d is set to have a higher magnetic permeability than the other magnetic body portions 11 as shown in FIG. As a result, the obtained waveform Sd includes a high permeability region w2 in which a waveform whose amplitude is increased by the Z signal magnetic body portion 11d and a low permeability region in which a waveform detected by the other magnetic body portion 11 is obtained. w1.

  FIG. 18 shows a detection block diagram of the rotary encoder. In FIG. 18, a circuit for detecting TDC is added to the configuration shown in FIG. Specifically, a comparator 54 is connected to the envelope detector 41, and the signal S8 input to the comparator 54 is taken out so as to obtain a signal S26 as a TDC signal. In the rotary encoder 8 of the third embodiment, the waveform Sd shown in FIG. 17B is input to the first detection coil pattern 16a, and the circuit is branched from the envelope detector 41 to obtain a signal. However, it does not prevent the comparator 54 from being connected to the envelope detector 42 or the envelope detector 43.

  Since the position sensor according to the third embodiment has the above-described configuration, the following effects and advantages are achieved.

  One magnetic permeability of the magnetic part 11 of the rotor pattern 13 formed on the outer peripheral surface of the rotor 10 of the rotary encoder 8 is different from that of the other magnetic part 11, and in the Z signal magnetic part 11d, The magnetic permeability is higher than that of the other magnetic part 11. For this reason, a high output portion as shown by the waveform Sd in FIG. 17B appears in the waveform detected by the first detection coil pattern 16a. This waveform Sd is input as a signal S1 by the first detection coil pattern 16a, and a high-frequency signal S5 is obtained via the differential amplifier 31. Thereafter, envelope detection is performed by the envelope detector 41 to obtain an output waveform S8.

  The output waveform S8 is input to the comparator 53, and a pulse signal S25 that becomes a Z signal is obtained by setting the reference voltage of the comparator 53 high. Through the comparator 53, the signal in the high permeability region w2 of the waveform Sd is obtained as one peak in the pulse signal S26, and this signal can be used as the Z signal. By doing so, a trigger signal can be obtained without providing the Z-phase detection coil 16d and the Z-phase magnetic body portion 20 as in the second embodiment, and the absolute position can be detected from the output on the detection coil 16 side. It becomes possible.

  As a result, a trigger signal can be obtained without increasing the thickness of the rotor 10 as in the case of the second embodiment, which can contribute to increasing the detection accuracy of the rotary encoder 8. The rotor pattern 13 of the third embodiment is provided with the Z signal magnetic body portion 11d at one location, but the magnetic permeability may be varied across the plurality of magnetic body portions 11 and the nonmagnetic body portion 12. . This is because the trigger signal can be detected even in that case. Further, it is not necessary to provide the Z-phase magnetic body portion 20 on the side surface of the rotor 10, and it is not necessary to provide the Z-phase detection coil 16 d on the stator 9, which contributes to improving the productivity of the rotary encoder 8. This leads to cost reduction.

  While the present invention has been described with reference to the embodiments, it is needless to say that the present invention is not limited to the above-described embodiments, and can be appropriately modified and applied without departing from the scope of the invention. For example, the exemplified materials do not preclude replacement with another material that performs the function. Moreover, the manufacturing method of the detection coil 16 and the excitation coil 17 does not prevent other manufacturing methods, such as the method of drawing and forming with an inkjet, besides the case of forming with a printed circuit board. In addition, the exemplified materials do not prevent replacement with another material that performs the function.

  Further, the back yoke 15 may be formed so as to be embedded in the stator body 26. Alternatively, the detection coil 16 and the excitation coil 17 may be formed in two layers on the flexible printed circuit board 23.

8 Rotary encoder 9 Stator 10 Rotor 11 Magnetic part 12 Nonmagnetic part 13 Rotor pattern 15 Back yoke 16 Detection coil 16a First detection coil pattern 16b Second detection coil pattern 16c Third detection coil pattern 17 Excitation coil 17a First excitation Coil pattern 17b Second excitation coil pattern 17c Third excitation coil pattern 17d Fourth excitation coil pattern 23 Flexible printed circuit board 24 Mounting member 25 Circuit portion 26 Stator main bodies 31, 32, 33, 34, 35 Differential amplifiers 41, 42, 43 Envelope detector 51, 52 Comparator

Claims (4)

A position sensor having a stator having an excitation coil and a detection coil formed in a planar shape, and a mover arranged opposite to the stator and having regions having different magnetic characteristics periodically arranged in the movement direction In
The detection coil includes a first detection coil pattern, a second detection coil pattern, and a third detection coil pattern,
The first detection coil pattern and the second detection coil pattern, the second detection coil pattern and the third detection coil pattern are arranged with a phase difference of 90 degrees,
The difference between the output signal from the first detection coil pattern and the output signal from the second detection coil pattern obtained by exciting the excitation coil, and the output signal from the second detection coil pattern and the A two-phase signal having a phase difference of 90 degrees is formed using a difference from the output signal from the third detection coil pattern,
A position sensor characterized by. The position sensor according to claim 1,
Envelope detection is performed for output signals from the first detection coil pattern, the second detection coil pattern, and the third detection coil pattern,
The envelope-detected output signal is input to a differential amplifier to calculate a difference, and the two-phase signal is formed,
A position sensor characterized by. The position sensor according to claim 1 or 2,
The mover is a cylindrical rotating body,
The regions having different magnetic properties are periodically arranged in the radial direction outer circumferential surface of the rotating body with respect to the rotating direction of the rotating body,
A magnetic region for Z phase is provided on the axial surface of the rotating body,
The stator is
The first detection coil pattern, the second detection coil pattern, and the third detection coil pattern are arranged facing the radially outer peripheral surface of the rotating body,
A fourth detection coil pattern for detecting the magnetic region for the Z phase is disposed opposite to the axial surface of the rotating body,
A position sensor characterized by. The position sensor according to claim 1 or 2,
The mover is a nonmagnetic metal mover base in which regions having different magnetic permeability from the nonmagnetic metal are periodically arranged in the moving direction of the mover.
The region having different magnetic permeability is configured by a plurality of patterns, and a part of the plurality of patterns is formed as a trigger region for Z signal detection having a different magnetic permeability from other patterns.
A position sensor characterized by.

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