JP2005164332A - Induction-type displacement detection device and micrometer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize high precision in an induction-type displacement detection device by making it hardly affected by the misalignment, while increasing the intensity the transmission signal flowing in the transmission coil. <P>SOLUTION: The induction type displacement detection device is a rotary type, and its transmission coil 105 is arranged in the stator. The transmission coil 105 extends from the terminal T1 in a ring shape, including the ring part 27 reaching the folding back part 25 and the ring part 29, with a radius different from that of the ring part 27 reaching the terminal T2 from the folding back part 25. The transmission coil 105 is composed of the upper conductor layer 15 and the lower conductor layer 17. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an inductive displacement detection device that detects displacement using magnetic flux coupling and is applied to small measuring tools represented by calipers and micrometers, rotary encoders, linear encoders, and sensor devices.

Conventionally, inductive displacement detectors have been used for precise measurements such as linear displacement and angular displacement. This detection device includes a linear type and a rotary type. The linear-type inductive displacement detection device includes a scale in which magnetic flux coupling windings are arranged at a predetermined pitch, a transmission winding and a reception coil that are arranged so as to be relatively movable with respect to the scale and are magnetically coupled to the magnetic flux coupling winding And a sensor head in which windings are arranged (for example, Patent Document 1). On the other hand, in a rotary type inductive displacement detection device, a transmission winding and a reception winding are disposed in a stator, and a conductive plate that performs the same function as a magnetic flux coupling winding is disposed in a rotor (for example, Patent Document 2). .
Japanese Patent Laid-Open No. 10-318781 (FIG. 1) JP-A-8-313295 (FIG. 16)

  The inductive displacement detection device is used for precise measurement. However, when crosstalk occurs, that is, when magnetic flux coupling is performed at a place where magnetic flux coupling is not desired, the resolution is lowered and the accuracy of displacement detection is degraded. In particular, in the case of a structure in which the transmission winding extends from one end to the transmission folded portion and then folds from here to the other end, crosstalk at the transmission folded portion becomes a problem. In addition, the accuracy of displacement detection also decreases due to the fact that the transmission current flowing through the transmission winding is small and the sensor head and scale are susceptible to misalignment.

  The present invention has been made to solve such a problem, and an object thereof is to provide a highly accurate inductive displacement detector.

  A first inductive displacement detection device according to the present invention includes a stator and a rotor arranged so as to face each other, and a plurality of reception loops configured to extend in a wave shape and be folded back again in a wave shape at a reception folding portion. Including a receiving winding disposed in the stator, a first ring portion extending in a ring shape from one end and reaching the transmission folded portion, and the other end extending from the transmission folded portion in a ring shape with a radius different from that of the first ring portion. And a transmission winding disposed on the stator, and a magnetic flux coupling winding disposed on the rotor so as to be capable of magnetic flux coupling to the reception winding and the transmission winding. .

  According to the first inductive displacement detecting device of the present invention, the first winding portion extending from the one end in a ring shape to the transmission folding portion and the radius different from the first folding portion from the transmission folding portion. The second ring portion extending in a ring shape and reaching the other end is included. For this reason, the position of the transmission folding portion and the positions of the one end and the other end of the transmission winding can be close to each other.

  In the first inductive displacement detection device according to the present invention, (1) the transmission loopback section and the reception loopback section are separated by one reception loop or more, (2) the transmission loopback section overlaps with the reception winding. The (3) receiving folded part in the position can be in a position that can overlap with the region defined by the magnetic flux coupling winding. According to (1) to (3), the influence of noise can be reduced. Further, according to (2), since the reception winding and the transmission folding portion overlap each other, the crosstalk fluctuation amount can be reduced by always receiving the crosstalk. In the first inductive displacement detector according to the present invention, the reception winding may have a circular shape or an arc shape.

  A second inductive displacement detector according to the present invention includes a stator and a rotor arranged so as to face each other, a receiving winding constituted by arranging a plurality of receiving loops in an arc shape on the stator, and one end A ring having a radius different from that of the first ring part so as to follow the first winding part and extend from the transmission folding part to the reception winding part and extend to the transmission winding part so as to attach to and overtake the reception winding. A transmission winding disposed on the stator and including a second ring portion extending in a shape extending to the other end, and a magnetic flux coupling winding disposed on the rotor so as to be magnetically coupled to the reception winding and the transmission winding. It is characterized by providing.

  According to the second inductive displacement detection device of the present invention, the reception winding is formed in an arc shape and the transmission turn-up portion of the transmission winding is located at a position over the reception winding. The position of the winding can be separated from the transmission fold. Therefore, since the magnetic flux coupling between the transmission folded portion and the reception winding can be prevented or weakened, a highly accurate inductive displacement detection device can be realized. In the second inductive displacement detection device according to the present invention, the space between the transmission loopback portion and the reception winding can be set to be equal to or more than one reception loop.

  In the first and second inductive displacement detection devices according to the present invention, the transmission winding includes a lead portion extending from the second ring portion to the other end, the stator includes a substrate serving as a core layer, and the first ring The second ring portion and the receiving winding are disposed on one surface side of the substrate, and the transmission folded portion and the lead-out portion are disposed substantially parallel to each other on the same layer on the other surface side of the substrate. A shield layer that is electrically separated from the transmission folded portion and the extraction portion may be disposed between the layer where the portion and the extraction portion are disposed and the other surface of the substrate.

  According to this, even if the magnetic field generated in the transmission folding part and the magnetic field generated in the extraction part face the reception winding side, since the shield layer is present, these magnetic fields are attenuated. Therefore, it is possible to reduce or eliminate a measurement error caused by crosstalk occurring in one signal period.

  In the first and second inductive displacement detection devices according to the present invention, the transmission winding includes a lead portion extending from the second ring portion to the other end, the stator includes a substrate serving as a core layer, and the first ring The second ring portion and the receiving winding are disposed on one surface side of the substrate, and the transmission folded portion and the lead-out portion are disposed so as to overlap different layers on the other surface side of the substrate. Can be.

  According to this, since the transmission folding part and the extraction part are arranged so as to overlap each other, the magnetic field generated in the transmission folding part and the magnetic field generated in the extraction part cancel each other in the direction of the reception winding side. The magnetic field is attenuated. Therefore, it is possible to reduce or eliminate a measurement error caused by crosstalk occurring in one signal period.

  A third inductive displacement detecting device according to the present invention includes one and the other winding holding members arranged so as to face each other, and an upper layer conductor and a lower layer conductor that are spaced apart from each other in the vertical direction. A transmission winding disposed on one winding holding member, a receiving winding configured by arranging a plurality of reception loops along one of the transmission windings on one winding holding member, a transmission winding and a receiving winding And a magnetic flux coupling winding arranged on the other winding holding member so as to be magnetically coupled to the wire and movable relative to the transmission winding and the reception winding.

  According to the third inductive displacement detection device of the present invention, the transmission winding is composed of two layers of conductors (upper layer conductor, lower layer conductor). Therefore, the upper and lower transmission windings are connected in parallel. Therefore, the resistance of the transmission winding can be lowered, and the strength of the transmission signal can be increased. As a result, the S / N ratio is improved, so that a highly accurate inductive displacement detector can be realized. Further, according to the present invention, the transmission winding is composed of the upper layer conductor and the lower layer conductor, so that the planar area of the transmission winding does not increase. Therefore, since it can be made less susceptible to misalignment, the accuracy of the inductive displacement detector can be improved.

  In the third inductive displacement detection device according to the present invention, one winding holding member is a stator, the other winding holding member is a rotor, and the transmission winding extends from one end in a ring shape and is turned back. A second ring portion extending in a ring shape with a different radius from the first ring portion and the first ring portion and reaching the other end may be included. This is an application of the third inductive displacement detector according to the present invention to a rotary type.

  In the third inductive displacement detection device according to the present invention, one winding holding member is a sensor head, and the other winding holding member is a scale that can move relative to the sensor head in a linear direction, The transmission winding can include a first linear portion extending linearly from one end and reaching the transmission folded portion, and a second linear portion extending linearly from the transmission folded portion and reaching the other end. . This is an application of the third inductive displacement detector according to the present invention to a linear type.

  In the first to third inductive displacement detectors according to the present invention, the receiving winding can be positioned between the first ring portion and the second ring portion. According to this, since the radius of the region where the receiving winding is arranged can be increased, the area of the receiving winding can be increased. Therefore, since the intensity of the received signal can be increased, the S / N ratio can be improved and the accuracy of the inductive displacement detector can be increased.

  The first to third inductive displacement detectors according to the present invention can be mounted on a micrometer.

  According to the first inductive displacement detection device of the present invention, the position of the transmission folding portion and the positions of the one end and the other end of the transmission winding can be close to each other. Therefore, the noise-consideration part of the transmission winding can be regarded as one place. Therefore, since the degree of freedom in design is improved, the accuracy of the inductive displacement detection device can be increased. According to the second inductive displacement detection device of the present invention, the position of the reception winding can be separated from the transmission folding portion of the transmission winding, so that a highly accurate inductive displacement detection device can be realized. . According to the third inductive displacement detection device of the present invention, the intensity of the transmission signal flowing through the transmission winding can be increased and the influence of misalignment can be reduced. High accuracy can be achieved.

  Hereinafter, an inductive displacement detector according to the present invention (hereinafter, “inductive displacement detector” may be referred to as an “encoder”) will be described with reference to the drawings. In the figure, the same reference numerals are used to designate the same elements as those shown in the drawings already described, and the description thereof is omitted.

[First Embodiment]
The inductive displacement detector according to the first embodiment is a rotary encoder. By making the reception winding of this encoder into an arc shape, the reception winding is separated from the transmission folding portion of the transmission winding. This prevents crosstalk between the transmission loopback portion and the reception winding.

  FIG. 1 is a plan view of a stator 1 that is a constituent element of an encoder according to the first embodiment, and FIG. 2 is a plan view of a rotor 3. A stator (an example of one winding holding member) 1 and a rotor (an example of the other winding holding member) 3 are arranged to face each other. The rotor 3 is rotatably supported in the circumferential direction A. The stator 1 and the rotor 3 are configured by a printed circuit board or the like.

  First, the stator 1 in FIG. 1 will be described. The stator 1 includes an insulating substrate 7 made of resin or the like with a through hole 5 formed in the center. On the insulating substrate 7, three arc-shaped receiving windings 9, 11 and 13 are arranged so as to surround the through hole 5. These windings have the same structure, and the structure of the receiving winding will be described by taking the winding 9 as an example.

  FIG. 3 is a plan view of the reception winding 9. The receiving winding 9 has a plurality of sets U of an upper layer conductor 15 and a lower layer conductor 17 that three-dimensionally intersects with the upper layer conductor 15, and these sets U are arranged in an arc shape. An insulating layer (not shown) is disposed between the upper layer conductor 15 and the lower layer conductor 17. The end portion of the upper layer conductor 15 and the end portion of the lower layer conductor 17 are connected via a buried conductor 19 embedded in a through hole or via hole provided in the insulating layer. Therefore, the reception winding 9 has a configuration in which a plurality of substantially diamond-shaped reception loops 21 are arranged along the through hole 5 (FIG. 1). In other words, the reception winding 9 includes a plurality of reception loops 21 that are configured to extend in a wave shape (in this example, zigzag shape, but may be sin shape) and are folded back at the reception folding portion 22 to extend in a wave shape again. . FIG. 4 is a plan view of one receiving loop 21.

  In addition, the case where the upper layer conductor 15 and the lower layer conductor 17 are formed on one surface of the insulating substrate 7 (FIG. 1) is described. However, the upper layer conductor 15 is disposed on one surface of the insulating substrate 7, the lower layer conductor 17 is disposed on the other surface, and the embedded conductor 19 embedded in a through hole provided in the insulating substrate 7 causes the upper layer conductor 15. The structure which connected the edge part of this and the edge part of the lower layer conductor 17 may be sufficient.

  Returning to the description of FIG. The receiving windings 9, 11, and 13 are arranged with a phase shift of λ / 6. As shown in FIG. 3, λ is a dimension along the circumferential direction A (FIG. 2) of the two reception loops 21.

  A transmission winding 23 is disposed on the insulating substrate 7 so as to surround the reception windings 9, 11, and 13. Specifically, the transmission winding 23 extends in a ring shape (circular shape) from one end serving as the terminal T1 to the reception windings 9, 11, and 13 and extends to the transmission turn-up portion 25 (first ring). Ring portion), a transmission folding portion 25, and a ring extending in a ring shape (circular shape) with a radius different from that of the ring portion 27 so as to be attached to and overtake the receiving windings 9, 11, 13 from the transmission folding portion 25. A part 29 (an example of a second ring part) and a lead part 31 extending from the ring part 29 to the other end serving as the terminal T2 are configured.

  A ring portion 29 is positioned inside the ring portion 27, and the receiving windings 9, 11, and 13 are positioned between the ring portion 27 and the ring portion 29. The lead-out part 31 is located in a different layer from the ring part 27, the ring part 29 and the transmission folding part 25. This will be described with reference to FIG. FIG. 5 is a plan view of the transmission winding 23. The ring part 27, the ring part 29, and the transmission folded part 25 are located in the same layer as the upper layer conductor 15 (FIG. 3), and the lead-out part 31 is located in the same layer as the lower layer conductor 17 (FIG. 3).

  Next, the configuration of the rotor 3 will be described with reference to FIG. The rotor 3 has a disk-shaped insulating substrate 35 made of resin or the like having a through hole 33 formed in the center. A plurality of magnetic flux coupling windings 37 are arranged on the insulating substrate 35 so as to surround the through hole 33. A rotating shaft (not shown) is passed through the through hole 5 of the stator 1 in FIG. 1, and this rotating shaft is fixed to the through hole 33 of the rotor 3. Thereby, the rotor 3 is supported rotatably in the circumferential direction A. In this state, the magnetic flux coupling winding 37 faces the transmission winding 23 and the reception windings 9, 11, 13 of FIG. FIG. 6 is a plan view of the magnetic flux coupling winding 37. The magnetic flux coupling winding 37 is arranged on the rotor 3 (FIG. 2) so as to be capable of magnetic flux coupling to the receiving winding (receiving loop 21) and the transmitting winding 23. Therefore, the magnetic flux coupling winding 37 is disposed so as to be capable of magnetic flux coupling to the transmission winding 23 and the reception windings 9, 11, and 13 and is relatively movable with respect to the transmission winding 23 and the reception windings 9, 11, 13. It can be said.

  As shown in FIG. 2, a space for one magnetic flux coupling winding 37 is provided between the magnetic flux coupling windings 37 (it can also be called a space for one reception loop 21). The reason why this space is provided will be described with reference to FIG. FIG. 7 is a plan view of adjacent magnetic flux coupling windings 37 and the reception loop 21 when the space is not provided.

  The direction of the current flowing through the magnetic flux coupling winding 37 at a certain time is indicated by an arrow i1. At this time, the direction of the current flowing through the receiving loop 21-1 that is magnetically coupled to the magnetic flux coupling winding 37-1 and the receiving loop 21-2 that is magnetically coupled to the magnetic flux coupling winding 37-2 is as indicated by an arrow i2. Therefore, since the current flowing through the reception loop 21-1 and the current flowing through the reception loop 21-2 cancel each other, a reception signal cannot flow through the reception winding.

  Therefore, in the first embodiment, the space is provided between adjacent magnetic flux coupling windings 37. That is, only one of the adjacent magnetic flux coupling windings 37 in FIG. 7 is provided. As a result, only one of the adjacent receiving loops 21 can be magnetically coupled to the magnetic flux coupling winding 37 to prevent current cancellation. However, since the number of magnetic flux coupling windings 37 that can be disposed on the insulating substrate 35 is reduced as shown in FIG. 2, the strength of the signal received by the receiving winding cannot be increased. The magnetic flux coupling winding 37, the transmission winding 23, and the reception windings 9, 11, and 13 are made of a material having a low electrical resistance such as aluminum, copper, and gold.

  The terminals T3 and T4 of the reception winding 9, the terminals T5 and T6 of the reception winding 11, the terminals T7 and T8 of the reception winding 13, and the terminals T1 and T2 of the transmission winding 23 are displaced via wiring not shown. It is connected to an IC circuit 39 that performs calculation and control for measurement. The IC circuit 39 may be disposed on the stator 1 or may be attached to a component other than this.

  Note that the first embodiment is a case of three reception windings 9, 11, and 13, which are arranged out of phase with each other, that is, three-phase reception windings. However, according to the present invention, when there is one receiving winding (one-phase receiving winding), two receiving windings arranged out of phase with each other (two-phase receiving winding), the phases are shifted from each other. It may be the case of four or more receiving windings arranged in a row (receiving windings of four or more phases).

  Next, the operation of the encoder according to the first embodiment will be briefly described with reference to FIGS. 1, 2, and 8 taking a micrometer as an example. FIG. 8 is a front view of a micrometer 51 equipped with the displacement detection device. The stator 1 is fixed to the frame 53, and the rotor 3 is fixed to the thimble 55.

  For example, when coolant or oil of a machine tool enters the inside from the periphery of the spindle 65 during use at the manufacturing site, a digital micrometer using a conventional capacitive rotary encoder has malfunctioned. A digital micrometer using the inductive displacement detection device according to the present invention can detect displacement without malfunction because the detection principle is electromagnetic induction. Therefore, it is possible to provide a digital micrometer that is more excellent in environmental resistance than conventional ones.

  There are the following two main effects of the first embodiment. First, the first effect will be described. As shown in FIG. 1, in the transmission winding 23, the ring portion 27 and the ring portion 29 have a ring shape, and the transmission folded portion 25 and the lead portion 31 have a linear shape extending in the radial direction of the ring. is there. As described above, the direction in which the transmission winding 23 extends at the location of the transmission folding portion 25 and the extraction portion 31 is abruptly changed and has an irregular shape. For this reason, the distribution and intensity of the magnetic field formed by the transmission winding 23 changes in the vicinity of the transmission folding portion 25 and the extraction portion 31, and distortion occurs. Therefore, when the receiving windings 9, 11, and 13 are magnetically coupled (that is, crosstalk) with the transmission folding unit 25 and the extraction unit 31, the receiving windings 9, 11, and 13 are affected by the distorted magnetic field. The accuracy of is reduced.

  According to the first embodiment, the reception windings 9, 11, and 13 are formed in an arc shape, and the transmission folding portion 25 and the extraction portion 31 are located at locations where these windings are overtaken. The windings can be separated from the transmission folding unit 25 and the drawing unit 31 by a predetermined distance (for example, approximately 1.5 pieces of the reception loop 21). Therefore, it is possible to prevent the reception windings 9, 11, 13 from being magnetically coupled to the transmission folding unit 25 and the extraction unit 31, or to weaken the magnetic flux coupling. Therefore, according to the first embodiment, a highly accurate inductive displacement detector can be realized.

  The second effect of the first embodiment will be described in comparison with a modification of this embodiment. FIG. 9 is a plan view of a stator 71 according to this modification. The difference from the stator 1 in FIG. 1 is that the reception windings 9, 11, and 13 are arranged inside the ring portion 27 and the ring portion 29 of the transmission winding 23. This modification is also an embodiment of the present invention.

  Since the shape of the reception windings 9, 11, and 13 in FIGS. 1 and 9 is an arc shape, the area of the reception winding is smaller than that of the ring-shaped reception winding. This means that the received signal strength decreases. In the first embodiment shown in FIG. 1, the receiving windings 9, 11, and 13 are located between the ring portion 27 (an example of the first ring portion) and the ring portion 29 (an example of the second ring portion). ing. For this reason, the radius of the area | region where the receiving windings 9, 11, and 13 are arrange | positioned becomes larger than the modification shown in FIG. Therefore, according to the first embodiment, the area of the reception windings 9, 11, 13 can be made larger than that of the modified example, so that the intensity of the reception signal can be increased. As a result, the S / N ratio is improved, and the accuracy of the inductive displacement detector can be increased.

  According to the experiment by the present inventor, it has been found that the strength of the received signal is increased about 5 to 8 times in the stator 1 of the first embodiment shown in FIG. 1 compared to the stator 71 in FIG. The following can be said from this. (1) Since the gap between the stator 1 and the rotor 3 can be made several times (for example, 500 to 600 μm) wider than that of the modified example, the gap is more resistant to gap fluctuations, and the accuracy of displacement detection is improved. (2) Since the degree of freedom in designing the shape of the receiving windings 9, 11, and 13 is increased, it is possible to design a shape that improves misalignment characteristics. (3) Since the number of assembling steps of the inductive displacement detector can be reduced, or the component accuracy of the inductive displacement detector can be reduced, the cost of the inductive displacement detector can be reduced.

[Second Embodiment]
In the second embodiment, a measurement error caused by crosstalk generated in one signal cycle is reduced by providing a shield layer that shields the magnetic field from the transmission wrapping unit and the extraction unit. First, this crosstalk will be described.

  10 is a plan view showing the positional relationship between the transmission winding 23 and the reception winding 9 in FIG. 1 and the magnetic flux coupling winding 37 in FIG. As shown by an arrow B, crosstalk is generated in which the distorted magnetic field generated in the transmission folding portion 25 and the extraction portion 31 of the transmission winding 23 is transmitted to the reception winding 9 via the magnetic flux coupling winding 37. The relationship in which the magnetic flux coupling winding 37 is positioned between the reception winding 9 and the transmission turn-back portion 25 (leading portion 31) occurs every time the magnetic flux coupling winding 37 moves λ. If the time required for this movement is one signal period, crosstalk occurs in one signal period.

  According to the second embodiment, it is possible to reduce the influence of the crosstalk. The structure of the second embodiment will be described with reference to FIGS. 11 to 13 with a focus on differences from the structure of the first embodiment. FIG. 11 is a schematic diagram of a cross-section of a location where the transmission folded portion 25 and the extraction portion 31 of the stator 73 provided in the encoder according to the second embodiment are provided. FIG. 12 is a perspective view of the conductive portion (transmission folded portion 25, lead portion 31, shield layer 75, etc.) shown in FIG. FIG. 13 is a plan view of the transmission winding 77 of the encoder according to the second embodiment.

  A stator 73 shown in FIG. 11 includes an insulating substrate 7 serving as a core layer. The ring portion 27, the ring portion 29, and the reception winding (not shown) are disposed on the surface 79 (an example of one surface) side of the insulating substrate 7. Specifically, the embedded conductor 19 is embedded in a through hole 81 provided in the insulating substrate 7. A pad electrode 83 connected to the buried conductor 19 is formed on the surface 79. An insulating layer 85 is formed on the surface 79 of the insulating substrate 7 so as to cover the pad electrode 83. A first ring portion (not shown) and a ring portion 29 are formed on the insulating layer 85. End portions 87 and 89 of the ring portion 29 are connected to pad electrodes 83-1 and 83-2 through via holes formed in the insulating layer 85, respectively. A protective layer 91 is formed so as to cover the ring portion 29.

  On the back surface 93 (an example of the other surface) side of the insulating substrate 7, the transmission folded portion 25 and the extraction portion 31 are arranged. Specifically, a pad electrode 95 connected to the buried conductor 19 is formed on the back surface 93. A shield layer 75 electrically isolated from the pad electrode 95 is provided so as to surround the pad electrode 95. The shield layer 75 is also electrically separated from the transmission folded portion 25 and the extraction portion 31. An insulating layer 97 is formed so as to cover the pad electrode 95 and the shield layer 75.

  On the insulating layer 97, the transmission folded portion 25 and the lead portion 31 are formed. The transmission folded portion 25 and the lead-out portion 31 are disposed in the same layer on the back surface 93 side of the insulating substrate 7 so as to be substantially parallel to each other in the radial direction of the ring portions 27 and 29. The transmission folded portion 25 and the extraction portion 31 are covered with a shield layer 75. The transmission folded portion 25 and the extraction portion 31 are connected to the pad electrodes 95-1 and 95-2 through via holes provided in the insulating layer 97, respectively. A protective layer 99 is formed so as to cover the transmission folded portion 25 and the drawing portion 31.

  The transmission folded portion 25, the lead portion 31, the shield layer 75, the buried conductor 19, and the pad electrodes 83 and 95 are made of a material having a low electrical resistance such as aluminum, copper, or gold. Moreover, the material of the insulating layers 85 and 97 and the protective layers 91 and 99 is, for example, a silicon oxide film. In addition, when using a printed circuit board instead of the insulated substrate 7, these materials are resin which comprises a printed circuit board.

  The effects of the second embodiment will be described. As shown in FIG. 13, it is assumed that a current in the direction of arrow i flows through the transmission winding 77 at a certain time. A reverse current flows between the transmission loopback unit 25 and the extraction unit 31. As shown in FIG. 12, the magnetic field H <b> 1 is generated by the current flowing through the transmission folding unit 25 at this time, and the magnetic field H <b> 2 is generated by the current flowing through the extraction unit 31. In the region between the transmission folding unit 25 and the extraction unit 31, both the magnetic field H1 by the transmission folding unit 25 and the magnetic field H2 by the extraction unit 31 are in the upward direction (the direction in which the reception winding is disposed).

  Since the shield layer 75 is disposed between the layer where the transmission folded portion 25 and the extraction portion 31 are disposed and the back surface 93 of the insulating substrate 7, the magnetic field obtained by adding the magnetic field H1 and the magnetic field H2 is attenuated, Crosstalk generated in one signal period can be reduced (or eliminated). Therefore, measurement errors caused by crosstalk occurring in one signal cycle can be reduced (or eliminated), and the accuracy of the inductive displacement detector can be increased. According to the simulation of the present inventor, the measurement error caused by crosstalk generated in one signal period can be reduced to about half compared to the first embodiment.

  Here, the formation method of the shield layer 75, the transmission folding | returning part 25, and the extraction | drawer part 31 is demonstrated easily using FIG.11, FIG.14 and FIG.15. 14 and 15 show the same cross section as FIG. As shown in FIG. 14, a conductive film is deposited on the back surface 93 by sputtering, for example, and this conductive film is patterned by lithography and etching to form a shield layer 75 and a pad electrode 95.

  As shown in FIG. 15, an insulating layer 97 is formed by CVD, for example, so as to cover the shield layer 75 and the pad electrode 95, and a via hole 101 exposing the pad electrode 95 is formed by lithography and etching. Then, as shown in FIG. 11, a conductive film is deposited on the insulating layer 97 by sputtering or the like, and this conductive film is patterned using lithography and etching to form the transmission folded portion 25 and the lead portion 31. Besides this, it can be formed by a method of manufacturing a printed circuit board.

[Third Embodiment]
In 3rd Embodiment, the effect similar to 2nd Embodiment is achieved by arrange | positioning a transmission folding | returning part and an extraction | drawer part so that it may overlap with the different layer of the back surface side of a board | substrate. That is, measurement errors caused by crosstalk occurring in one signal cycle are reduced (or eliminated).

  The third embodiment will be described with reference to FIGS. 16 and 17 focusing on differences from the first and second embodiments. FIG. 16 is a schematic diagram of a cross section of a portion of the stator 103 provided with the transmission folded portion 25 and the extraction portion 31 provided in the encoder according to the third embodiment, and corresponds to FIG. 17 is a perspective view of the conductive portion (transmission folding portion 25, extraction portion 31 and the like) shown in FIG. 16, and corresponds to FIG.

  When viewed from the protective layer 99 side, the transmission folded portion 25 is formed in the lower layer portion, and the drawing portion 31 is formed in the upper layer portion so as to overlap the transmission folded portion 25. An insulating layer 97 is formed between the transmission folded portion 25 and the lead portion 31.

  Since the transmission folding unit 25 and the extraction unit 31 are arranged so as to overlap, the magnetic field H1 generated by the current flowing through the transmission folding unit 25 and the magnetic field H2 generated by the current flowing through the extraction unit 31 are canceled in the vertical direction. Fit. Therefore, according to the third embodiment, the same effect as in the second embodiment (crosstalk generated in one signal period can be reduced or eliminated) without providing a shield layer. According to the simulation of the present inventor, the measurement error caused by crosstalk generated in one signal period can be reduced to about one fifth compared with the first embodiment.

  In addition, in the left-right direction of the transmission folding | returning part 25 or the extraction part 31, since the direction of the magnetic field H1 and the direction of the magnetic field H2 are the same, it becomes a strong magnetic field. Therefore, if a shield layer is arranged in the same layer as the transmission folding unit 25 and the same layer as the extraction unit 31, the horizontal magnetic field can be shielded.

[Fourth Embodiment]
FIG. 18 is a plan view of the stator 133 of the encoder according to the fourth embodiment. Main differences from the first embodiment shown in FIG. 1 will be described. The reception windings 9, 11, and 13 have a circumferential shape. The transmission loopback portion 25 and the lead-out portion 31 of the transmission winding 23 and the reception loopback portion 22 of the reception windings 9, 11, 13 are separated by one or more reception loops 21 (FIG. 4). The transmission loopback unit 25 and the lead-out unit 31 are in positions that overlap the reception windings 9, 11, and 13. The transmission folded portion 25 and the lead-out portion 31 are the same as the structure shown in FIGS. 11 and 12, and are disposed on the back surface 93 of the insulating substrate 7.

  Here, the reception folding unit 22 according to the fourth embodiment will be described using the reception winding 9 as an example. FIG. 19 is a plan view of the vicinity of the reception folding portion 22 of the reception winding 9. The reception folded portion 22 is formed at two locations on both the front end side 135 and the end side 137 of the reception winding 9. Specifically, the upper layer conductor 15 is folded at the reception folded portion 22 at the distal end side 135, and the lower layer conductor 17 is folded at the reception folded portion 22 at the distal end side 137.

  A simulation was performed for the fourth embodiment. FIG. 20 is a diagram showing models 1 to 3 of the transmission winding 139 and the reception winding 141 used in this simulation. In any of the models 1 to 3, the transmission loopback unit 25 and the reception loopback unit 22 are separated by one reception loop (FIG. 4).

  The transmission folding unit 25 and the drawing unit 31 of the model 1 do not overlap the reception winding 141, and the transmission folding unit 25 and the drawing unit 31 are arranged in parallel (see FIGS. 11 and 12). The drawing unit 31 is separated from the reception folding unit 22 by (distance between the transmission folding unit 25 and the drawing unit 31) + (one reception loop). On the other hand, the transmission folding unit 25 and the extraction unit 31 of the model 2 overlap the reception winding 141, and the arrangement of the transmission folding unit 25 and the extraction unit 31 is the same as that of the model 1. Similarly to the model 2, the transmission folding unit 25 and the extraction unit 31 of the model 3 overlap the reception winding 141, and the transmission folding unit 25 and the extraction unit 31 are arranged to overlap (FIG. 16 and FIG. 16). FIG. 17).

  FIG. 21 is a graph showing simulation results. The vertical axis represents the ratio of noise generated in the receiving winding to the signal flowing through the receiving winding, and shows how much the noise becomes when the signal strength is 100%. In any of the models 1 to 3, the signal strength ratio is small. Therefore, if the transmission loopback unit 25 (drawing unit 31) and the reception loopback unit 22 are further separated from one reception loop, the signal strength ratio is further decreased. I guess it can be done. Therefore, the accuracy of the inductive displacement detector can be improved by separating the transmission loopback unit 25 and the extraction unit 31 from the reception loopback unit 22 by one reception loop or more.

  Further, as can be seen from FIG. 21, the signal intensity ratio of model 3 is the smallest, model 2 is the next smallest, and model 1 is the next smallest. Therefore, from the viewpoint of the signal strength ratio, the models 3, 2, and 1 are preferable in this order.

  Now, since the terminals T1 to T8 also cause noise, referring to the previous simulation, the noise consideration point of the reception winding and the noise consideration point of the transmission winding are separated by one or more reception loops. The influence of can be reduced. There are two places where noise is taken into consideration in the reception winding, one is the reception folding section 22 and the other is the terminals T3 to T8. There are also two places where noise is taken into account in the transmission winding, one being the transmission folding portion 25 and the leading portion 31, and the other being the terminals T1 and T2.

  Here, consider a case where the design is separated by one reception loop or more. Since the reception windings 9, 11, and 13 are circumferential, the reception folded portion 22 and the terminals T3 to T8 can be arranged at close positions. Therefore, the noise-considering part of the receiving winding can be regarded as one place.

  When the transmission loopback part 25 is disposed relatively far from the terminals T1 and T2 (Comparative Example 1), the noise-consideration points of the transmission winding must be regarded as two points. Therefore, in consideration of both of these two locations (the transmission loopback unit 25 and the terminals T1 and T2), the noise-considering location of the reception winding must be arranged. Therefore, the degree of freedom in design is reduced. In particular, when the reception winding has an arc shape as shown in FIG. 1 (Comparative Example 2), the reception folding portion 22 is disposed relatively far from the terminals T3 to T8. Must be considered. Therefore, the degree of freedom in design is further reduced.

  On the other hand, the transmission winding 23 of the fourth embodiment shown in FIG. 18 includes a ring portion 27 extending from the terminal T1 (one end) in a ring shape and reaching the transmission folding portion 25, and from the transmission folding portion 25 to the ring portion 27. A ring portion 29 extending in a ring shape with a small radius and reaching the terminal T2 (the other end) is included. For this reason, the position of the transmission folding | returning part 25 and the position of terminal T1, T2 can be made close. For this reason, since the noise consideration part of the transmission winding 23 can be considered as one place, the freedom degree of design can be improved. As a modification of the fourth embodiment, even when the reception windings 9, 11, and 13 are arcuate as shown in FIG. Compared with 2, design freedom can be improved. As described above, according to the fourth embodiment, since the degree of freedom in design is improved, a highly accurate inductive displacement detector can be realized.

  Moreover, the reception folding | returning part 22 of 4th Embodiment exists in the position which can overlap with the area | region (signal detection area | region) prescribed | regulated by the magnetic flux coupling coil | winding 37, as shown in FIG. When the reception loopback unit 22 is outside the signal detection area, it becomes a new noise source. According to the fourth embodiment, the generation of this noise source can be prevented.

[Fifth Embodiment]
In the fifth embodiment, the signal strength of the transmission winding is increased by configuring the transmission winding with an upper layer conductor and a lower layer conductor that are spaced apart from each other in the vertical direction. Since the fifth embodiment is the same as the first embodiment except for the configuration of the transmission winding, the transmission winding will be mainly described.

  FIG. 22 is a perspective view of the transmission winding 105 of the encoder according to the fifth embodiment. The transmission winding 105 is disposed on the stator 1 shown in FIG. The transmission winding 105 extends in a ring shape from one end, which is the terminal T1, and reaches the transmission folded portion 25, and the other end, which extends in a ring shape from the transmission folded portion 25 with a different radius from the ring portion 27, and is the terminal T2. The ring part 29 which leads to is included.

  Similar to the reception winding 9 shown in FIG. 3 of the first embodiment, the transmission winding 105 includes an upper layer conductor 15 and a lower layer conductor 17 that are spaced apart from each other in the vertical direction. That is, the upper conductor 15 and the lower conductor 17 are branched by the buried conductor 19 at a location that extends from the terminal T1 and becomes the beginning of the ring portion 27, and the upper conductor 15 by the buried conductor 19 at a location that ends the ring portion 29. And the lower conductor 17 merge. As can be seen from the above, the ring portion 27, the transmission folded portion 25, and the ring portion 29 are composed of the upper layer conductor 15 and the lower layer conductor 17, and the lead portion 31 is composed of only the lower layer conductor 17. A lower layer conductor 17 is located directly below the upper layer conductor 15.

  The receiving winding of the fifth embodiment is the same as the receiving windings 9, 11, and 13 of the first embodiment of FIG. However, the receiving winding of the fifth embodiment may be a ring shape instead of an arc shape. Further, the magnetic flux coupling winding according to the fifth embodiment is arranged on the rotor as in the first embodiment of FIG. The effect of the fifth embodiment will be described later in the [Simulation] column.

[Sixth Embodiment]
The encoder according to the sixth embodiment is a linear encoder, and the transmission winding has a two-layer structure of an upper layer conductor and a lower layer conductor as in the fifth embodiment. For example, a caliper is mounted as the inductive displacement detection device according to the sixth embodiment. A sixth embodiment will be described with reference to FIGS. FIG. 23 is a plan view of the sensor head 107 of the encoder according to the sixth embodiment, FIG. 24 is a plan view of the scale 109, and FIG. 25 is a perspective view of the transmission winding 111.

  The encoder according to the sixth embodiment includes a scale 109 (an example of the other winding holding member) and a sensor head 107 (an example of the one winding holding member) disposed to face the scale 109. A part of the scale 109 in the longitudinal direction appears. The sensor head 107 is disposed so as to be movable along the measurement axis x with a predetermined gap with respect to the scale 109. Note that the sensor head may be fixed and the scale may move. That is, the sensor head and the scale may be arranged so as to be relatively movable in the linear direction.

  A sensor head 107 shown in FIG. 23 has an insulating substrate 113 such as glass or silicon. A rectangular transmission winding 111 is arranged on the surface of the insulating substrate 113 facing the scale 109. Specifically, the transmission winding 111 is folded back from a linear portion 115 (an example of a first linear portion) that extends linearly (linearly) from one end to the transmission folded portion 25, a transmission folded portion 25, and the like. A linear portion 117 (an example of a second linear portion) that extends linearly and reaches the other end. As shown in FIG. 25, the transmission winding 111 extends from the terminal T 1 and branches to the upper layer conductor 15 and the lower layer conductor 17 by the embedded conductor 19 at the beginning of the linear portion 115, and the end of the linear portion 117. The upper layer conductor 15 and the lower layer conductor 17 are joined by the embedded conductor 19 at a certain point.

  Reception windings 119, 121, and 123 are arranged on the surface side of the insulating substrate 113 facing the scale 109 and next to the transmission winding 111. These receiving windings are obtained by linearizing the receiving windings 9, 11 and 13 shown in FIG.

  The scale 109 includes an insulating substrate 125 such as glass or silicon (a printed circuit board may be used instead of the insulating substrate 125), and the surface side of the substrate 125 facing the sensor head 107 is along the longitudinal direction of the scale 109. Thus, the magnetic flux coupling winding 127 is linearly arranged. The magnetic flux coupling winding 127 is formed of a closed linear conductor including a receiving conductor 129 that can be magnetically coupled to the transmission winding 111 and a transmission conductor 131 that can be magnetically coupled to the receiving windings 119, 121, and 123. The effect of the sixth embodiment will be described in the next [Simulation] column.

[simulation]
According to the fifth and sixth embodiments, the intensity of the transmission signal flowing through the transmission winding can be increased and the influence of misalignment can be reduced. This effect will be described based on simulation. FIG. 26 is a diagram showing a transmission winding model used in this simulation. (A) is a plan view of models 1 to 4, (B) is a perspective view of model 5, and (C) is a plan view of model 6.

  The models 1 to 6 are all rectangular. As shown in (A), models 1 to 4 are composed of only the upper layer conductor 15, the line width w of model 1 is 100 μm, that of model 2 is 200 μm, that of model 3 is 300 μm, and model 4 It is 400 μm. As shown in (B), the model 5 has a line width w of 100 μm and is composed of an upper layer conductor 15 and a lower layer conductor 17. This is a transmission winding of the fifth and sixth embodiments, in which the transmission winding is constituted by two conductive layers provided in parallel. As shown in (C), the model 6 has a line width w of 100 μm and is divided into two upper layer conductors 15 at the beginning of the linear portion 115, and the two upper layer conductors 15 merge at the end of the linear portion 117. . This parallelizes the transmission windings on the same plane.

  First, simulations relating to the magnitude of transmission current (that is, transmission signal) were performed for models 1 to 6. The graph of FIG. 27 shows the values of the transmission currents flowing through the models 1 to 6 when the transmission excitation signals having the same amplitude, wavelength and frequency are given to the models 1 to 6. The value of the transmission current flowing through the model 1 is 100%. As can be seen from the models 1 to 4, the line width and the transmission current value have a correlation, and the transmission current value increases as the line width increases.

  Since model 5 (fifth and sixth embodiments) and model 6 have transmission windings arranged in parallel, the cross-sectional area of the transmission winding can be made larger than that of model 1. Therefore, the models 5 and 6 have a smaller transmission winding resistance than the model 1, so that the transmission current can be increased.

  Next, simulation about misalignment was performed for models 1-6. Misalignment is misalignment between the stator and the rotor (sensor head and scale) that occurs when the inductive displacement detector is assembled. If this deviation is large, high-precision measurement is hindered.

  FIG. 28 is a plan view of the magnetic flux coupling winding 127 and the transmission winding 111 for explaining this simulation. The induced voltage generated in the transmission conductor 131 of the magnetic flux coupling winding 127 by the current passed through the transmission winding 111 was calculated. FIG. 29 shows the relationship between the induced voltage rate and the lateral deviation of the transmission winding 111. As a misalignment, a lateral shift of the transmission winding 111 is taken as an example. The horizontal axis indicates the lateral displacement, and the vertical axis indicates the induced voltage rate. The induced voltage rate is 100% when the lateral deviation of the transmission winding 111 is zero for each model.

  What can be said about each model is that the induced voltage ratio decreases as the lateral displacement increases. Further, when the models 1 to 4 are compared with, for example, a lateral displacement of 300 μm, the induced voltage ratio increases as the line width decreases. This indicates that when the line width is reduced, it is less susceptible to lateral misalignment.

  The reason why the induced voltage ratio decreases (becomes susceptible to misalignment) as the line width of the transmission winding increases is as follows. Referring to FIG. 28, if the space between the linear portion 115 and the linear portion 117 is large, the magnetic flux coupling between the transmission winding 111 and the receiving conductor 129 even if the transmission winding 111 is slightly displaced in the lateral direction due to misalignment. The induced voltage rate is unlikely to decrease. When the line width of the transmission winding 111 is increased, the space between the linear portion 115 and the linear portion 117 is reduced, and therefore, the transmission winding 111 is easily affected by misalignment.

  In other words, if the ratio of the area of the transmission winding to the total pattern (that is, the reception winding + transmission winding) area increases, it becomes susceptible to misalignment. In order to make the misalignment characteristics the same as model 1 without changing the total pattern area in models 2, 3 and 4, the size of the reception winding must be reduced, and the received signal strength is reduced. turn into.

  The model 6 has a line width of 100 μm and is the same as the model 1. However, since the model 6 extends in parallel on the same plane, the space between the linear part 115 and the linear part 117 is smaller than that of the model 1. For this reason, model 6 has a smaller induced voltage ratio than model 1.

  Even in the same parallel, the model 5 (fifth and sixth embodiments) is parallelized in the upper and lower layers, so the space between the linear part 115 and the linear part 117 is the same as the model 1. For this reason, model 5 has the same induced voltage ratio as model 1, and is less susceptible to misalignment than other models. As described above, the model 5 can make the transmission current larger than that of the model 1.

  As can be seen from the above description, according to the model 5 (fifth and sixth embodiments), it is possible to increase the strength of the transmission signal and make it less susceptible to misalignment. Therefore, according to the fifth and sixth embodiments, a highly accurate inductive displacement detector can be realized.

It is a top view of the stator of the encoder which concerns on 1st Embodiment. It is a top view of the rotor of the encoder which concerns on 1st Embodiment. It is a top view of the receiving winding arrange | positioned at the stator of FIG. It is a top view of the receiving loop which comprises a receiving coil | winding. It is a top view of the transmission winding arrange | positioned at the stator of FIG. FIG. 3 is a plan view of a magnetic flux coupling winding disposed in the rotor of FIG. 2. It is a top view of the adjacent magnetic flux coupling coil | winding and receiving loop in case the space for one receiving loop is not provided. It is a front view of the micrometer in which the encoder concerning a 1st embodiment is built. It is a top view of the stator which concerns on the modification of 1st Embodiment. FIG. 3 is a plan view showing the positional relationship between the transmission winding and reception winding of FIG. 1 and the magnetic flux coupling winding of FIG. 2. It is a schematic diagram of the cross section of the location in which the transmission folding | turning part and extraction part of the stator with which the encoder which concerns on 2nd Embodiment is equipped are provided. It is a perspective view of the electroconductive part (transmission folding | returning part, drawer | drawing-out part, shield layer, etc.) appearing in FIG. It is a top view of the transmission winding with which the encoder concerning a 2nd embodiment is equipped. It is a 1st process figure for demonstrating the formation method of the shield layer with which the encoder which concerns on 2nd Embodiment is equipped, a transmission folding | returning part, and the extraction | drawer part. It is the 2nd process drawing. It is a schematic diagram of the cross section of the location in which the transmission folding | turning part and extraction part of the stator with which the encoder which concerns on 3rd Embodiment is equipped are provided. It is a perspective view of the electroconductive part (transmission folding | returning part, drawer | drawing-out part, etc.) appearing in FIG. It is a top view of the stator of the encoder which concerns on 4th Embodiment. It is a top view near the reception folding | turning part of the reception winding arrange | positioned at the stator of 4th Embodiment. It is a figure which shows the model of the transmission winding used by the simulation for demonstrating the effect of 4th Embodiment, and a reception winding. It is a graph which shows the signal strength ratio of the receiving winding of the models 1-3 of FIG. It is a perspective view of the transmission coil | winding of the encoder which concerns on 5th Embodiment. It is a top view of the sensor head of the encoder which concerns on 6th Embodiment. It is a top view of the scale of the encoder which concerns on 6th Embodiment. It is a perspective view of the transmission coil | winding of the encoder which concerns on 6th Embodiment. It is a figure which shows the model of the transmission winding used in the simulation for demonstrating the effect of 5th and 6th embodiment. It is a graph which shows the value of the transmission current which can be sent through the models 1-6 of FIG. FIG. 27 is a plan view of a magnetic flux coupling winding and a transmission winding for explaining a simulation with respect to an alignment variation for models 1 to 6 in FIG. 26. It is a graph which shows the result of the simulation with respect to the alignment fluctuation | variation about the models 1-6 of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Stator, 3 ... Rotor, 5 ... Through-hole, 7 ... Insulating substrate, 9, 11, 13 ... Reception winding, 15 ... Upper layer conductor, 17 ... Lower layer Conductor, 19 ... buried conductor, 21 ... receiving loop, 22 ... receiving folded portion, 23 ... transmitting winding, 25 ... transmitting folded portion, 27 ... ring portion (first Ring part (an example of the second ring part), 31 ... an extraction part, 33 ... a through hole, 35 ... an insulating substrate, 37 ... magnetic flux coupling Winding, 39 ... IC circuit, 51 ... micrometer, 53 ... frame, 55 ... thimble, 59 ... transmission signal generation circuit for transmission, 61 ... reception signal processing circuit, 63 ... Operation control circuit, 65 ... Spindle, 71, 73 ... Stator, 75 ... Shield layer, 77 ... Transmitting winding, 79 ... surface, 81 ... through hole, 83 ... pad electrode, 85 ... insulating layer, 87,89 ... end, 91 ... protective layer, 93 ... -Back surface, 95 ... Pad electrode, 97 ... Insulating layer, 99 ... Protective layer, 101 ... Via hole, 103 ... Stator, 105 ... Transmission winding, 107 ... Sensor head , 109 ... scale, 111 ... transmission winding, 113 ... insulating substrate, 115 ... linear part (first linear part), 117 ... linear part (second linear part), 119, 121, 123 ... receiving winding, 125 ... insulating substrate, 127 ... magnetic flux coupling winding, 129 ... receiving conductor, 131 ... transmitting conductor, 133 ... stator, 135 ... ..Front end side, 137... End side, 139... Transmission winding, 141 ..Receiving windings, T1 to T8... Terminal, U... Set of upper layer conductor and lower layer conductor, A... Circumferential direction, i, i1, i2. Measuring axis

Claims (15)

A stator and a rotor arranged to face each other;
A reception winding disposed in the stator and including a plurality of reception loops configured to extend in a wave shape and be folded back and waved again at the reception folded portion;
A first ring portion extending in a ring shape from one end and reaching a transmission folded portion; and a second ring portion extending from the transmission folded portion in a ring shape with a radius different from that of the first ring portion and reaching the other end A transmission winding disposed on the stator;
A magnetic flux coupling winding disposed on the rotor so as to be capable of magnetic flux coupling to the reception winding and the transmission winding;
An inductive displacement detection device comprising: The transmission loopback unit and the reception loopback unit are separated by one or more reception loops,
The inductive displacement detection device according to claim 1. The transmission folded portion is at a position overlapping the receiving winding.
The inductive displacement detection device according to claim 1 or 2, characterized in that The reception folded portion is at a position where it can overlap with a region defined by the magnetic flux coupling winding,
The inductive displacement detection device according to any one of claims 1 to 3, wherein The receiving winding has a circumferential shape;
The inductive displacement detection device according to any one of claims 1 to 4, wherein The receiving winding has an arc shape;
The inductive displacement detection device according to any one of claims 1 to 4, wherein A stator and a rotor arranged to face each other;
A receiving winding constituted by arranging a plurality of receiving loops in an arc shape on the stator;
A first ring portion extending in a ring shape so as to be attached to and overtaken from the receiving winding from one end and reaching the transmission folding portion, and the first ring to be attached to and overtaken from the transmission folding portion to the receiving winding Including a second ring portion extending in a ring shape with a different radius from the portion and reaching the other end, and being disposed on the stator,
A magnetic flux coupling winding disposed on the rotor so as to be capable of magnetic flux coupling to the reception winding and the transmission winding;
An inductive displacement detection device comprising: The space between the transmission folded portion and the reception winding is equal to or more than one reception loop.
The inductive displacement detection device according to claim 7. The transmission winding includes a lead portion extending from the second ring portion to the other end,
The stator includes a substrate serving as a core layer,
The first ring portion, the second ring portion, and the reception winding are disposed on one surface side of the substrate,
The transmission folded portion and the lead-out portion are disposed substantially parallel to each other on the same layer on the other surface side of the substrate,
A shield layer electrically separated from the transmission folded portion and the leading portion is disposed between the layer where the transmitting folded portion and the leading portion are disposed and the other surface of the substrate.
The inductive displacement detection device according to any one of claims 1 to 8, wherein The transmission winding includes a lead portion extending from the second ring portion to the other end,
The stator includes a substrate serving as a core layer,
The first ring portion, the second ring portion, and the reception winding are disposed on one surface side of the substrate,
The transmission folded part and the lead-out part are arranged so as to overlap different layers on the other surface side of the substrate,
The inductive displacement detection device according to any one of claims 1 to 8, wherein One and the other winding holding members arranged to face each other;
A transmission winding including an upper layer conductor and a lower layer conductor spaced apart from each other in the vertical direction and disposed on the one winding holding member;
A receiving winding configured by arranging a plurality of receiving loops on the one winding holding member along the transmitting winding;
A magnetic flux coupling winding that is disposed on the other winding holding member so as to be capable of magnetic flux coupling to the transmission winding and the reception winding, and is movable relative to the transmission winding and the reception winding;
An inductive displacement detection device comprising: The one winding holding member is a stator,
The other winding holding member is a rotor,
The transmission winding extends in a ring shape from one end and reaches a transmission folded portion, and a second ring extends from the transmission folded portion in a ring shape with a radius different from that of the first ring portion and reaches the other end. Including the ring part of
The inductive displacement detection device according to claim 11. The one winding holding member is a sensor head,
The other winding holding member is a scale that can move relative to the sensor head in a linear direction,
The transmission winding includes a first linear portion extending linearly from one end and reaching a transmission folded portion, and a second linear portion extending linearly from the transmission folded portion and reaching the other end,
The inductive displacement detection device according to claim 11. The receiving winding is located between the first ring portion and the second ring portion;
The inductive displacement detector according to any one of claims 1 to 10 and 12.   A micrometer equipped with the inductive displacement detection device according to any one of claims 1 to 10, 12, and 14.

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