Position detection device

Abstract

A position detection device for detecting the position of a displaceable object to be detected (10) is provided with a substrate (20), a transmission coil (30), and a reception coil (40), the substrate (20) is disposed so as to face the object to be detected (10), the transmission coil (30) extends in the plane direction of the substrate (20), and the reception coil (40) has a plurality of spiral parts (41) in which wires are formed in a spiral shape and arranged in the displacement direction of the object to be detected (10). Inductively coupling by electromagnetic induction caused by energizing the transmission coil (30); a connecting line (42) that electrically connects the plurality of spiral sections (41) to each other; and a parallel line (43) electrically connected to the vortex part (41) and the connecting line (42) and parallel to the connecting line (42).

Description

[0001] Cross-references of related applications

[0002] This application is based on Japanese Patent Application No. 2022-193691 filed on December 2, 2022, the contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a position detection device. Background Art

[0004] In the past, a position detection device for detecting the position of a detected object has been proposed. For example, the position detection device described in Patent Document 1 includes: a transmitting coil and a receiving coil mounted on a substrate; and a target arranged opposite to the substrate. The receiving coil has a plurality of vortex portions with wiring formed in a spiral shape and a connecting wire electrically connecting the plurality of vortex portions to each other. The position detection device applies an alternating current to the transmitting coil and detects the position of the target based on a characteristic value (e.g., output voltage) of the receiving coil that changes in accordance with the displacement of the target.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: U.S. Patent Application Publication No. 2022 / 0011138A1 Summary of the invention

[0008] However, in the position detection device described in Patent Document 1, if an alternating current is applied to the transmitting coil, an induced current is generated in the vortex portion and the connecting wire at the portion of the receiving coil corresponding to the opening of the target. The inventors of the present disclosure have found that the induced current generated in the connecting wire is the main reason for the output voltage offset of the receiving coil that changes in accordance with the displacement of the detected object. If the offset value of the output voltage of the receiving coil deviates from the signal adjustment range of the signal processing unit (such as IC), there is a problem that the accuracy of position detection deteriorates. In addition, the offset refers to the deviation of the average value of the waveform of the output voltage that changes in accordance with the displacement of the detected object from the ideal waveform to the positive side or the negative side.

[0009] An object of the present disclosure is to improve the detection accuracy of a position detection device.

[0010] According to one viewpoint of the present disclosure, a position detection device detects the position of a displaceable detected object, comprising: a substrate arranged opposite to the detected object; a transmitting coil extending in the surface direction of the substrate; and a receiving coil having a plurality of vortex portions, connecting wires and parallel wires, wherein the wiring of the plurality of vortex portions is formed in a spiral shape and arranged in the displacement direction of the detected object, and is inductively coupled by electromagnetic induction caused by energizing the transmitting coil, the connecting wire electrically connects the plurality of vortex portions to each other, and the parallel wire is electrically connected to the vortex portions and the connecting wire and is parallel to the connecting wire.

[0011] Thus, when an alternating current is applied to the transmitting coil, at least a portion of the magnetic field generated by the current flowing in the connecting wire and at least a portion of the magnetic field generated by the current flowing in the parallel wire cancel each other out. Therefore, the waveform of the characteristic value (e.g., output voltage) of the receiving coil that changes in accordance with the displacement of the detected object is suppressed from deviating from the ideal waveform. Therefore, the position detection device prevents the characteristic value of the receiving coil from deviating from the adjustment range of the signal processing unit, so that the detection accuracy can be improved.

[0012] Furthermore, at least a portion of the magnetic field generated by the current flowing in the connecting line and at least a portion of the magnetic field generated by the current flowing in the parallel line cancel each other out, which means that all of the magnetic fields may be canceled out, or only a portion of the magnetic fields may be canceled out.

[0013] In addition, since the position detection device has a structure in which the receiving coil has a plurality of swirls, the occupancy rate of the receiving coil wiring per unit area of ​​the substrate (hereinafter referred to as "occupancy rate") can be increased. Therefore, the position detection device can increase the amplitude of the output voltage of the receiving coil and improve the detection accuracy.

[0014] In addition, the reference numerals in parentheses given to each component etc. represent an example of the correspondence relationship between the component etc. and the specific component etc. described in the embodiment described later. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a plan view showing the position detection device according to the first embodiment.

[0016] Figure 2 yes Figure 1 Cross-sectional view of line II-II.

[0017] Figure 3 It is a perspective view showing the first receiving coil according to the first embodiment.

[0018] Figure 4 It is a perspective view showing the second receiving coil according to the first embodiment.

[0019] Figure 5A FIG. 1 is a diagram showing a portion of the first receiving coil mounted on the first layer of the multi-layer substrate.

[0020] Figure 5B This is a diagram showing a portion of the first receiving coil that is mounted on the second layer of the multi-layer substrate.

[0021] Figure 5C This is a diagram showing a portion of the first receiving coil mounted on the third layer of the multi-layer substrate.

[0022] Fig. 6A This is a diagram showing a portion of the second receiving coil that is mounted on the first layer of the multi-layer substrate.

[0023] Figure 6B FIG. 1 is a diagram showing a portion of the second receiving coil mounted on the second layer of the multi-layer substrate.

[0024] Figure 6C This is a diagram showing a portion of the second receiving coil mounted on the third layer of the multi-layer substrate.

[0025] Figure 7 is a graph showing the output voltage of the first receiving coil and the output voltage of the second receiving coil.

[0026] Figure 8 This is a block diagram of the position detection device according to the first embodiment.

[0027] Fig. 9 This is a graph comparing the amplitude of the output voltage of the first receiving coil included in the position detection device according to the first embodiment and the amplitude of the output voltage of the first receiving coil included in the position detection device of the first comparative example (ie, a device without a swirl portion).

[0028] Fig.10 This is a graph comparing the output voltage of the first receiving coil included in the position detection device according to the first embodiment and the output voltage of the first receiving coil included in the position detection device of the second comparative example (ie, a device without parallel wires).

[0029] Fig.11 It is a plan view showing a position detection device according to a second embodiment.

[0030] Fig.12 It is a perspective view showing a first receiving coil according to the second embodiment.

[0031] Fig.13 It is a perspective view showing a second receiving coil according to the second embodiment.

[0032] Fig.14 It is a plan view showing a position detection device according to a first comparative example.

[0033] Fig.15 It is a perspective view showing a first receiving coil according to a second comparative example.

[0034] Fig.16 1 is a perspective view showing a second receiving coil according to a second comparative example. DETAILED DESCRIPTION

[0035] Hereinafter, the embodiments of the present disclosure will be described with reference to the accompanying drawings. In addition, in each of the following embodiments and comparative examples, the same reference numerals are given to the parts that are identical or equivalent to each other, and their descriptions are omitted. In addition, the arrows indicating one side and the other side shown in each figure are recorded for the convenience of description, and one side and the other side may also be replaced.

[0036] (First Embodiment)

[0037] A first embodiment will be described with reference to the drawings.

[0038] like Figure 1 and Figure 2 As shown in FIG. 1 , the position detection device includes a substrate 20, a transmitting coil 30, a receiving coil 40, and a signal processing unit 50, and is an inductive sensor for detecting the position of a target 10 as a detected object. Figure 1 20. In FIG. 2, wirings arranged in a plurality of layers of the substrate 20 are shown overlapping. Figure 3 to Figure 6C As shown, in this embodiment, a configuration in which wirings constituting the receiving coil 40 and the like are provided on three layers of the substrate 20 will be described as an example.

[0039] like Figure 2 As shown in the figure, the target 10 is formed of a conductor such as metal and is fixed to the rotating shaft 60. The target 10 is rotated and displaced together with the rotating shaft 60 with the axis CL of the rotating shaft 60 as the center. In addition, the target 10 can also be rotated and displaced by more than 360 degrees, or can be rotated and displaced within a range of 360 degrees. In the following description, the direction in which the axis CL of the rotating shaft 60 extends is referred to as the "axial direction", the radial direction of the imaginary circle perpendicular to the axis CL of the rotating shaft 60 is referred to as the "radial direction", and the circumferential direction of the imaginary circle is referred to as the "circumferential direction".

[0040] exist Figure 1 , the outer edges of the target 10 and the rotating shaft 60 are indicated by single-dot chain lines. The target 10 is formed in a substantially annular shape. The target 10 has one or more (for example, four) teeth 11 formed in the circumferential direction, and one or more (for example, four) openings 12 formed between the teeth 11. The teeth 11 and the openings 12 are arranged in the displacement direction (i.e., circumferential direction) of the target 10. In addition, the shape and size of the teeth 11 and the openings 12 of the target 10 are not limited to Figure 1As shown, it is appropriately set according to the magnitude of the output voltage of the receiving coil 40 required for the signal processing of the signal processing unit 50, for example.

[0041] like Figure 2 As shown, the substrate 20 is composed of, for example, a multilayer substrate, and is arranged opposite to the target 10. A predetermined gap AG is provided between the substrate 20 and the target 10. The substrate 20 is fixed to a fixed body (for example, a vehicle body or a component fixed to the vehicle body, etc.) not shown. Therefore, the rotating shaft 60 and the target 10 rotate relative to the substrate 20.

[0042] like Figure 1 As shown, the transmitting coil 30 is provided in an arbitrary layer of the substrate 20 and extends in the surface direction of the substrate 20. In the present embodiment, the transmitting coil 30 is wound a plurality of times so as to surround the radially outer side of the receiving coil 40. One end and the other end of the wiring of the transmitting coil 30 are connected to the signal processing unit 50, respectively.

[0043] like Figure 3 to Figure 6C As shown, the receiving coil 40 has a plurality of vortex portions 41, a connecting wire 42, a parallel wire 43, and the like. The plurality of vortex portions 41 are portions where the wiring is formed into a spiral shape. The plurality of vortex portions 41 are arranged at positions where the inductive coupling is caused by electromagnetic induction caused by energizing the transmitting coil 30. The plurality of vortex portions 41 are arranged in the displacement direction of the target 10. The direction in which the plurality of vortex portions 41 are arranged is substantially the same as the direction in which the transmitting coil 30 extends. Therefore, the plurality of vortex portions 41 are arranged in the direction in which the transmitting coil 30 extends. In addition, the plurality of vortex portions 41 are arranged on the radially inner side of the transmitting coil 30 wound into a ring shape. The wiring constituting the plurality of vortex portions 41 is preferably arranged at the maximum occupancy ratio on the basis of ensuring the clearance required for insulation.

[0044] The connection wire 42 is a portion that electrically connects the plurality of vortex portions 41. Therefore, the connection wire 42 is provided at a plurality of locations between the plurality of vortex portions 41.

[0045] The parallel line 43 is electrically connected to the swirl portion 41 and the connection line 42, and is a portion parallel to the connection line 42. The parallel line 43 is parallel to at least a part or all of the connection lines 42 at a plurality of locations.

[0046] In this embodiment, the receiving coil 40 includes a first receiving coil 410 and a second receiving coil 420 .

[0047] like Figure 1 , Figure 3 and Figure 5A to Figure 5C As shown, the first receiving coil 410 has a plurality of first vortex portions 411, a first connecting line 412 and a first parallel line 413. In addition, Figure 5A to Figure 5CThe circle in the figure represents a via hole. That is, the plurality of first spiral portions 411 , the first connection wires 412 , the first parallel wires 413 and the like constituting the first receiving coil 410 are electrically connected in one stroke via the via hole.

[0048] For the sake of convenience, the following Figure 1 As shown in FIG. 1 and FIG. 2 , one of the first vortex portions 411 disposed with a predetermined second vortex portion 421 (for example, a Cos+ coil) interposed therebetween is referred to as a Sin+ coil, and the other first vortex portion 411 is referred to as a Sin− coil.

[0049] exist Figure 5A and Figure 5B In FIG. 1 , the arrows recorded on the outside of each first vortex portion 411 indicate the direction in which the current flows in the wiring of each first vortex portion 411 at a predetermined instantaneous value of the alternating current applied to the transmitting coil 30. Figure 5A and Figure 5B As shown, at a predetermined instantaneous value of the AC current, the current flows counterclockwise in one first vortex portion 411 (eg, Sin+ coil), and the current flows clockwise in the other first vortex portion 411 (eg, Sin- coil).

[0050] like Figure 7 As shown by the solid line A, the first receiving coil 410 is a receiving coil 40 that outputs a sinusoidal signal as the target 10 is displaced. The first receiving coil 410 outputs a voltage value corresponding to the magnitude of the induced current generated by the Sin+ coil and the Sin- coil at the position corresponding to the opening 12 of the target 10. For the Sin+ coil and the Sin- coil, the distance between the center of the Sin+ coil and the center of the Sin- coil is set so that the phase of the waveform of the output voltage corresponding to the displacement of the target 10 differs by 180 degrees in electrical angle.

[0051] like Figure 5A and Figure 5B As shown, the first connection line 412 electrically connects the plurality of first vortex portions 411. In the present embodiment, the first connection line 412 connects the radially outer portions of the plurality of first vortex portions 411.

[0052] like Figure 5C As shown, the first parallel line 413 is electrically connected to the plurality of first vortex portions 411 and the first connecting line 412, and is parallel to the first connecting line 412. The first parallel line 413 and the first connecting line 412 are arranged in different layers at overlapping positions in the thickness direction of the substrate 20. Therefore, in the present embodiment, the first parallel line 413 is arranged at a position radially outside the plurality of first vortex portions 411.

[0053] The first connection line 412 and the first parallel line 413 are electrically connected via the first folding portion 414. In the present embodiment, the first folding portion 414 is formed by a via hole that electrically connects the first connection line 412 and the first parallel line 413, which are respectively provided in two different layers of the substrate 20. The first connection line 412 and the first parallel line 413 are arranged in two different layers of the substrate 20 in such a manner as to be folded back via the via hole serving as the first folding portion 414. Therefore, the first connection line 412 and the first parallel line 413 are arranged as follows: in a specified instantaneous value of the alternating current applied to the transmitting coil 30, the direction of the current flowing through a specified portion of the first connection line 412 and the direction of the current flowing through a specified portion of the first parallel line 413 adjacent to the portion are opposite directions.

[0054] In addition, as described above, the first connecting wire 412 and the first parallel wire 413 are arranged at positions overlapping in the thickness direction of the substrate 20 in two different layers of the substrate 20. Therefore, the first connecting wire 412 and the first parallel wire 413 are arranged adjacent to each other. Specifically, the adjacent arrangement refers to being arranged at a distance such that at least a portion of the magnetic field generated by the current flowing in the first connecting wire 412 due to the alternating current applied to the transmitting coil 30 and at least a portion of the magnetic field generated by the current flowing in the first parallel wire 413 cancel each other out.

[0055] like Figure 1 , Figure 4 and Figure 6A to Figure 6C As shown, the second receiving coil 420 has a plurality of second vortex portions 421, second connecting lines 422 and second parallel lines 423. In addition, Figure 6A to Figure 6C The circle in the figure also represents a via hole. That is, the plurality of second spiral portions 421 , the second connection wires 422 , the second parallel wires 423 and the like constituting the second receiving coil 420 are electrically connected in one stroke through the via hole.

[0056] For the sake of convenience, the following Figure 1 As shown in FIG. 1 and the like, one of the second vortex portions 421 disposed across a predetermined first vortex portion 411 (eg, Sin-coil) is sometimes referred to as a Cos+coil, and the other second vortex portion 421 is sometimes referred to as a Cos-coil.

[0057] exist Fig. 6A and Figure 6B In FIG. 4 , the arrows recorded on the outside of each second vortex portion 421 indicate the direction in which the current flows in the wiring of each second vortex portion 421 at another instantaneous value of the alternating current applied to the transmitting coil 30. Fig. 6A and Figure 6BAs shown, in another instantaneous value of the AC current, the current flows counterclockwise in one second vortex portion 421 (eg, Cos+ coil), and the current flows clockwise in the other second vortex portion 421 (eg, Cos- coil).

[0058] like Figure 7 As shown by the dotted line B, the second receiving coil 420 is a receiving coil 40 that outputs a sinusoidal voltage signal with a phase different from the waveform of the voltage signal of the first receiving coil 410 as the target 10 is displaced. The waveform of the output voltage of the first receiving coil 410 and the waveform of the output voltage of the second receiving coil 420 differ by 90 degrees in electrical angle. Therefore, the waveform of the output voltage of the second receiving coil 420 can also be called a cosine wave. The second receiving coil 420 outputs a voltage value corresponding to the magnitude of the induced current generated from the Cos+ coil and the Cos- coil at the position corresponding to the opening 12 of the target 10.

[0059] For the Cos+ coil and the Cos- coil, the distance between the center of the Cos+ coil and the center of the Cos- coil is set so that the phase of the waveform of the output voltage corresponding to the displacement of the target 10 is different by 180 degrees in electrical angle. In addition, for the Sin+ coil and the Cos+ coil, the distance between the center of the Sin+ coil and the center of the Cos+ coil is set so that the phase of the waveform of the output voltage corresponding to the displacement of the target 10 is different by 90 degrees in electrical angle. In addition, for the Sin- coil and the Cos- coil, the distance between the center of the Sin- coil and the center of the Cos- coil is set so that the phase of the waveform of the output voltage corresponding to the displacement of the target 10 is different by 90 degrees in electrical angle.

[0060] like Fig. 6A and Figure 6B As shown, the second connection line 422 electrically connects the plurality of second vortex portions 421. In the present embodiment, the second connection line 422 connects the radially inner portions of the plurality of second vortex portions 421.

[0061] like Figure 6C As shown, the second parallel line 423 is electrically connected to the plurality of second vortex portions 421 and the second connecting line 422, and is parallel to the second connecting line 422. The second parallel line 423 and the second connecting line 422 are provided in different layers at positions overlapping in the thickness direction of the substrate 20. Therefore, in the present embodiment, the second parallel line 423 is provided at a position radially inward of the plurality of second vortex portions 421.

[0062] The second connection line 422 and the second parallel line 423 are electrically connected via the second folding portion 424. In the present embodiment, the second folding portion 424 is formed by a via hole that electrically connects the second connection line 422 and the second parallel line 423 that are respectively provided on two different layers of the substrate 20. The second connection line 422 and the second parallel line 423 are configured in a manner of folding back via the via hole that serves as the second folding portion 424 in two different layers of the substrate 20. Therefore, the second connection line 422 and the second parallel line 423 are configured as follows: in a specified instantaneous value of the alternating current applied to the transmitting coil 30, the direction of the current flowing through a specified portion of the second connection line 422 and the direction of the current flowing through a specified portion of the second parallel line 423 adjacent to the portion are opposite directions.

[0063] In addition, as described above, the second connecting wire 422 and the second parallel wire 423 are provided in two different layers of the substrate 20 at positions overlapping in the thickness direction of the substrate 20. Therefore, the second connecting wire 422 and the second parallel wire 423 are arranged adjacent to each other. Specifically, the adjacent arrangement refers to being arranged at a distance such that at least a portion of the magnetic field generated by the current flowing in the second connecting wire 422 due to the alternating current applied to the transmitting coil 30 and at least a portion of the magnetic field generated by the current flowing in the second parallel wire 423 cancel each other out.

[0064] like Figure 8 As shown, an electronic control circuit 21 is provided on the substrate 20, and the electronic control circuit 21 includes a microcomputer having a processor and a memory. The electronic control circuit 21 reads a program from the memory through the processor and executes it, thereby performing various control operations. In addition, various data used when executing the program are stored in advance in the memory.

[0065] Specifically, the electronic control circuit 21 includes a signal processing unit 50 connected to the transmitting coil 30, the first receiving coil 410, and the second receiving coil 420 to perform a predetermined process. The signal processing unit 50 includes, for example, an oscillating unit 51, a demodulating unit 52, an AD converter 53, an offset and gain correction unit 54, an angle calculating unit 55, an output unit 56, etc., and is composed of an integrated circuit (IC). In addition, the following description is made using an example of converting to a digital signal and processing as a representative example, but in the case of using an analog signal for processing, the signal processing unit 50 may not include the AD converter 53, etc.

[0066] The oscillator 51 is electrically connected to the transmission coil 30 and applies an alternating current of a predetermined frequency to the transmission coil 30. At this time, the magnetic field generated by the transmission coil 30 causes an induced current to flow through the first reception coil 410 and the second reception coil 420.

[0067] The demodulator 52 is connected to the first receiving coil 410 and the second receiving coil 420 , respectively. The demodulator 52 generates a first demodulated signal by demodulating the first voltage value V1 output from the first receiving coil 410 , and generates a second demodulated signal by demodulating the second voltage value V2 output from the second receiving coil 420 .

[0068] The AD converter 53 generates a first converted signal by performing AD conversion on the first demodulated signal, and generates a second converted signal by performing AD conversion on the second demodulated signal.

[0069] The offset and gain correction unit 54 performs offset correction and gain correction on the first conversion signal and the second conversion signal. In addition, generally, in the signal processing unit 50 (for example, IC), an adjustment range specification in which offset correction and gain correction can be performed is preset. In other words, it is a specification as follows: if the first voltage value V1 and the second voltage value V2 deviate from the adjustment range specification, the signal processing unit 50 cannot correctly perform offset correction and gain correction.

[0070] The angle calculation unit 55 calculates the position (i.e., mechanical angle) of the target 10 based on the signals after the offset correction and gain correction of the first conversion signal and the second conversion signal, for example, by calculating the arc tangent function. The output unit outputs the mechanical angle of the target 10 calculated by the angle calculation unit 55 to the output terminal 57.

[0071] Next, the first voltage value V1 of the first receiving coil 410 and the second voltage value V2 of the second receiving coil 420 when the target 10 is rotationally displaced (specifically, rotationally moved around the axis CL) will be described.

[0072] When an alternating current of a predetermined frequency is applied to the transmitting coil 30, a magnetic field is generated that passes through the first receiving coil 410 and the second receiving coil 420. Since the magnetic field changes according to the alternating current, an induced electromotive force is generated in the first receiving coil 410 and the second receiving coil 420 by electromagnetic induction.

[0073] At this time, an eddy current is generated in the teeth 11 of the target 10 at a position opposite to the transmitting coil 30, the first receiving coil 410, and the second receiving coil 420, and a magnetic field caused by the eddy current is generated. Therefore, the magnetic field of the portion opposite to the teeth 11 of the target 10 among the magnetic fields passing through the first receiving coil 410 and the second receiving coil 420 is offset by the magnetic field caused by the eddy current.

[0074] Furthermore, as the target 10 is rotated and displaced, the positions of the first receiving coil 410 and the second receiving coil 420 that are opposite to the teeth 11 and the opening 12 of the target 10 change. Therefore, the first voltage value V1 generated in the first receiving coil 410 and the second voltage value V2 generated in the second receiving coil 420 change periodically as the target 10 is rotated and displaced. In this embodiment, for example, Figure 7 As shown, the first voltage value V1 generated in the first receiving coil 410 becomes a sine wave, and the second voltage value V2 generated in the second receiving coil 420 becomes a cosine wave with the same wavelength as the first voltage value V1.

[0075] Here, for comparison with the position detection device of the first embodiment described above, two position detection devices of comparative examples will be described.

[0076] (First Comparative Example)

[0077] First, a position detection device according to a first comparative example will be described.

[0078] like Fig.14 As shown, the receiving coil 40 provided in the position detection device of the first comparative example has a first receiving coil 410 formed into a sine wave shape, and a second receiving coil 420 formed into a cosine wave shape. In addition, the first receiving coil 410 is wired in one stroke, and the second receiving coil 420 is also wired in one stroke. In the first comparative example, as the mechanical angle of the target 10 is displaced, the first receiving coil 410 outputs a sine wave voltage signal, and the second receiving coil 420 outputs a cosine wave voltage signal.

[0079] However, the amplitude of each of the output voltages of the first receiving coil 410 and the second receiving coil 420 of the first comparative example is much smaller than the amplitude of each of the output voltages of the first receiving coil 410 and the second receiving coil 420 of the first embodiment.

[0080] Fig. 9 This is a graph comparing the amplitude of the output voltage of the receiving coil 40 according to the first embodiment and the amplitude of the output voltage of the receiving coil 40 according to the first comparative example. Fig. 9 The horizontal axis represents the gap between the substrate 20 and the target 10 , and the vertical axis represents the average value of the amplitude.

[0081] like Fig. 9 As shown, in any case of the gap of 2 to 6 (mm), the amplitude of the output voltage of the receiving coil 40 of the first embodiment is larger than the amplitude of the output voltage of the receiving coil 40 of the first comparative example. This is based on the following two reasons.

[0082] The first reason is that when the receiving coil 40 is formed into a sine wave shape and a cosine wave shape as in the first comparative example, the occupancy rate of the wiring of the receiving coil 40 relative to the substrate 20 becomes small. In contrast, in the first embodiment, since the receiving coil 40 has a shape having a plurality of spiral portions 41, the occupancy rate of the wiring of the receiving coil 40 relative to the substrate 20 can be increased.

[0083] The second reason is that, when the receiving coil 40 is made into a sine wave shape or a cosine wave shape as in the first comparative example, if the wiring of the same shape is provided in each layer of the substrate 20, the number of vias used to connect the wiring of each phase increases. Since the wiring of each layer is arranged to avoid the via, the occupancy rate of the wiring of the receiving coil 40 relative to the substrate 20 becomes smaller. In contrast, in the first embodiment, the receiving coil 40 has a shape having a plurality of vortex portions 41. Therefore, when the wiring of the same shape is provided in each layer of the substrate 20, the vias used to connect the wiring of each phase only need to be arranged in the center and the periphery of the vortex portion 41. Therefore, in the first embodiment, it is possible to prevent the occupancy rate of the wiring of the receiving coil 40 relative to the substrate 20 from becoming smaller due to the via.

[0084] For the above reasons, the position detection device of the first embodiment can increase the amplitude of the output voltage of the receiving coil 40 by increasing the occupancy rate of the wiring of the receiving coil 40 with respect to the substrate 20 as compared with the position detection device of the comparative example.

[0085] (Second Comparative Example)

[0086] Next, a position detection device according to a second comparative example will be described. Fig.15 4 is a diagram showing a first receiving coil 410 provided in a position detection device according to a second comparative example. Fig.16 2 is a diagram showing a second receiving coil 420 provided in the position detection device of the second comparative example. In the second comparative example, the first receiving coil 410 and the second receiving coil 420 are also arranged on the same substrate 20 so that the first vortex portions 411 and the second vortex portions 421 are alternately arranged in the circumferential direction.

[0087] like Fig.15 As shown, the first receiving coil 410 of the second comparative example has a plurality of first vortex portions 411 and a first connecting line 412 electrically connecting the plurality of first vortex portions 411 to each other, but does not have the first parallel line 413 described in the first embodiment. Fig.16 As shown, the second receiving coil 420 of the second comparative example has a plurality of second vortex portions 421 and a second connection line 422 electrically connecting the plurality of second vortex portions 421 to each other, but does not have the second parallel line 423 described in the first embodiment.

[0088] In the second comparative example, if an alternating current is applied to the transmitting coil 30, an induced current is also generated in the vortex portion 41 and the connecting wire 42 at the portion of the receiving coil 40 corresponding to the opening portion 12 of the target 10. At this time, the induced current generated in the connecting wire 42 becomes a major factor causing the output voltage of the receiving coil 40 to shift, which changes in accordance with the displacement of the target 10. In the second comparative example, if the offset value of the output voltage of the receiving coil 40 deviates from the signal adjustment range of the signal processing unit 50 (for example, IC), the offset correction and gain correction are not correctly performed, and there is a problem that the accuracy of position detection is deteriorated.

[0089] Fig.10 This is a graph comparing the output voltage of the receiving coil 40 according to the first embodiment and the output voltage of the receiving coil 40 according to the first comparative example.

[0090] like Fig.10 As shown in FIG. 1 , the offset value of the output voltage of the receiving coil 40 of the first embodiment is improved by 1 / 24 times compared with the offset value of the output voltage of the receiving coil 40 of the first comparative example. As a result, the position detection device of the first embodiment can make the offset value of the output voltage of the receiving coil 40 fall within the signal adjustment range of the signal processing unit 50 (e.g., IC). Therefore, for the position detection device of the first embodiment, since the signal adjustment function (e.g., offset correction and gain correction) based on the signal processing unit 50 operates normally, the accuracy of position detection can be improved.

[0091] As described above, the position detection device according to the first embodiment has the following effects compared to the position detection devices of the first comparative example and the second comparative example.

[0092] (1) In the position detection device of the first embodiment, the receiving coil 40 includes a plurality of vortex portions 41 , a connecting wire 42 electrically connecting the plurality of vortex portions 41 to each other, and a parallel wire 43 parallel to the connecting wire 42 .

[0093] Thus, when an alternating current is applied to the transmitting coil 30, at least a portion of the magnetic field generated by the current flowing through the connecting wire 42 and at least a portion of the magnetic field generated by the current flowing through the parallel wire 43 cancel each other out. Therefore, the waveform of the output voltage of the receiving coil 40 that changes in accordance with the displacement of the target 10 is suppressed from deviating from the ideal waveform. Therefore, the position detection device can improve the detection accuracy because it can prevent the output voltage of the receiving coil 40 from deviating from the adjustment range of the signal processing unit 50.

[0094] In addition, since the receiving coil 40 of the position detection device has a plurality of spiral portions 41, the area occupied by the wiring of the receiving coil 40 relative to the substrate 20 can be increased. Therefore, the amplitude of the output voltage of the receiving coil 40 is increased, and the detection accuracy can be improved.

[0095] (2) In the first embodiment, the connecting wire 42 and the parallel wire 43 are configured as follows: in a specified instantaneous value of the alternating current applied to the transmitting coil 30, the direction of the current flowing through a specified portion of the connecting wire 42 and the direction of the current flowing through a specified portion of the parallel wire 43 adjacent to the specified portion of the connecting wire 42 are opposite directions.

[0096] Thus, when an alternating current is applied to the transmission coil 30 , at least a portion of the magnetic field generated by the current flowing through the connection wire 42 and at least a portion of the magnetic field generated by the current flowing through the parallel wire 43 can cancel each other out.

[0097] (3) In the first embodiment, the connecting wire 42 and the parallel wire 43 are arranged adjacent to each other. Specifically, the adjacent arrangement means that they are arranged at a distance such that at least a portion of the magnetic field generated by the current flowing in the connecting wire 42 due to the alternating current applied to the transmitting coil 30 and at least a portion of the magnetic field generated by the current flowing in the parallel wire 43 cancel each other out.

[0098] As a result, since the generation of the induced current from the connection line 42 is suppressed, it is possible to prevent the average value of the output voltage of the receiving coil 40 from greatly deviating from 0 mV.

[0099] (4) In the first embodiment, the connection lines 42 are provided at a plurality of locations between the plurality of vortex portions 41. The parallel lines 43 are provided corresponding to at least a part or all of the plurality of connection lines 42.

[0100] This cancels out magnetic fields generated by currents flowing through at least a portion or all of the connection wires 42 , suppressing the generation of induced currents from the connection wires 42 , thereby preventing the average value of the output voltage of the receiving coil 40 from greatly deviating from 0 mV.

[0101] (5) In the first embodiment, the connection lines 42 and the parallel lines 43 are provided on different layers of the substrate 20 .

[0102] Thus, the connection line 42 and the parallel line 43 can be arranged adjacent to each other in different layers of the substrate 20 .

[0103] (6) In the first embodiment, the receiving coil 40 includes a first receiving coil 410 and a second receiving coil 420. The first receiving coil 410 includes a first vortex portion 411 on one side, a first vortex portion 411 on the other side, a first connecting wire 412 electrically connecting the first vortex portion 411 on one side with the first vortex portion 411 on the other side, and a first parallel wire 413 parallel to the first connecting wire 412. In addition, the first vortex portion 411 on one side is, for example, a Sin+ coil, and the first vortex portion 411 on the other side is, for example, a Sin- coil. The second receiving coil 420 includes a second vortex portion 421 on one side, a second vortex portion 421 on the other side, a second connecting wire 422 electrically connecting the second vortex portion 421 on one side with the second vortex portion 421 on the other side, and a second parallel wire 423 parallel to the second connecting wire 422. In addition, the second vortex portion 421 on one side is, for example, a Cos+ coil, and the second vortex portion 421 on the other side is, for example, a Cos- coil. Furthermore, one first vortex portion (eg, Sin+ coil), one second vortex portion (eg, Cos+ coil), another first vortex portion (eg, Sin- coil), and another second vortex portion (eg, Cos- coil) are arranged in this order.

[0104] Thus, the specific configurations of the first receiving coil 410 and the second receiving coil 420 included in the receiving coil 40 are exemplified.

[0105] (7) In the first embodiment, the distance between the center of the first vortex portion 411 on one side and the center of the first vortex portion 411 on the other side arranged with the predetermined second vortex portion 421 sandwiched therebetween is set so that the phase of the waveform of the output voltage corresponding to the displacement of the target 10 differs by 180 degrees in electrical angle. In addition, the distance between the center of the second vortex portion 421 on one side and the center of the second vortex portion 421 on the other side arranged with the predetermined first vortex portion 411 sandwiched therebetween is set so that the phase of the output voltage differs by 180 degrees in electrical angle.

[0106] Thus, one of the output voltage of the first receiving coil 410 and the output voltage of the second receiving coil 420 corresponding to the displacement of the target 10 can be made into a sine wave shape, and the other can be made into a sine wave shape (ie, a cosine wave shape) with a phase shifted from the sine wave shape.

[0107] (Second Embodiment)

[0108] Since the second embodiment has a partially changed structure compared to the first embodiment, only the parts different from the first embodiment will be described.

[0109] like Fig.11 and Fig.12As shown, in the position detection device of the second embodiment, the first receiving coil 410 has a first vortex portion 411 on one side, a first vortex portion 411 on the other side, a first connecting line 412, and a first parallel line 413. In addition, the first connecting line 412 electrically connects the first vortex portion 411 on one side with the first vortex portion 411 on the other side. The first parallel line 413 is electrically connected to the first vortex portion 411 and the first connecting line 412, and is parallel to the first connecting line 412.

[0110] In addition, if Fig.11 and Fig.13 As shown, the second receiving coil 420 has a second vortex portion 421 on one side, a second vortex portion 421 on the other side, a second connecting line 422, and a second parallel line 423. In addition, the second connecting line 422 electrically connects the second vortex portion 421 on one side with the second vortex portion 421 on the other side. The second parallel line 423 is electrically connected to the second vortex portion 421 and the second connecting line 422, and is parallel to the second connecting line 422. Fig.11 As shown, the first swirl portions 411 and the second swirl portions 421 are arranged in an alternating manner.

[0111] In the second embodiment, when an alternating current is applied to the transmitting coil 30, at least a portion of the magnetic field generated by the current flowing through the connecting wire 42 and at least a portion of the magnetic field generated by the current flowing through the parallel wire 43 also cancel each other. Therefore, the waveform of the output voltage of the receiving coil 40 that changes according to the displacement of the target 10 is suppressed from deviating from the ideal waveform. Therefore, the position detection device of the second embodiment can also achieve the same effect as the first embodiment.

[0112] (Other embodiments)

[0113] (1) In the above-mentioned embodiments, the receiving coil 40 is provided on three layers of the substrate 20, but the present invention is not limited thereto. For example, the receiving coil 40 may be provided on one layer of the substrate 20, or may be provided on two layers, or may be provided on four or more layers of the substrate 20. Therefore, each vortex portion 41 may be provided on one layer of the substrate 20, or may be provided on three or more layers.

[0114] (2) In the above-mentioned embodiments, the parallel wires 43 and the connecting wires 42 are arranged in different layers of the substrate 20 at positions overlapping in the thickness direction of the substrate 20, but the present invention is not limited thereto. For example, the parallel wires 43 and the connecting wires 42 may be arranged adjacent to each other in the same layer of the substrate 20 at a distance such that at least a portion of the magnetic field generated by the current flowing in the connecting wires 42 and at least a portion of the magnetic field generated by the current flowing in the parallel wires 43 cancel each other out.

[0115] (3) In the above-mentioned embodiments, the target 10 as the object to be detected is described as being rotationally displaced, but the present invention is not limited thereto. For example, the target 10 may be displaced in a linear or curved shape.

[0116] (4) In the above embodiments, the characteristic value of the receiving coil 40 is described as a voltage value, but the present invention is not limited thereto. For example, the characteristic value of the receiving coil 40 may be a current value or an inductance.

[0117] The present disclosure is not limited to the embodiments described, but can be appropriately changed. In addition, the above-mentioned embodiments and a part thereof are not unrelated to each other, and can be appropriately combined except for the case that they are obviously not combined. In addition, in the above-mentioned embodiments, the elements constituting the embodiments are not necessarily necessary, except for the cases that are specifically indicated as necessary and the cases that are obviously considered to be necessary in principle. In addition, in the above-mentioned embodiments, when referring to the numerical values ​​of the number, value, amount, range, etc. of the constituent elements of the embodiments, except for the cases that are specifically indicated as necessary and the cases that are obviously limited to a specific number in principle, it is not limited to the specific number. In addition, in the above-mentioned embodiments, when referring to the shape, positional relationship, etc. of the constituent elements, etc., except for the cases that are specifically indicated and the cases that are limited to a specific shape, positional relationship, etc. in principle, it is not limited to its shape, positional relationship, etc.

[0118] The control unit and method described in the present disclosure may also be implemented by a special-purpose computer as follows: the special-purpose computer is provided by a processor and a memory programmed to execute one or more functions embodied by a computer program. Alternatively, the control unit and method described in the present disclosure may also be implemented by a special-purpose computer as follows: the special-purpose computer is provided by a processor composed of one or more special-purpose hardware logic circuits. Alternatively, the control unit and method described in the present disclosure may also be implemented by one or more special-purpose computers as follows: the one or more special-purpose computers are composed of a processor and a memory programmed to execute one or more functions and a processor composed of one or more hardware logic circuits. In addition, the computer program may also be stored in a computer-readable non-transitory tangible recording medium as an instruction executed by a computer. The above-mentioned memory is a non-transitory physical storage medium,

[0119] (Viewpoints of this publication)

[0120] The present disclosure described above can be understood as, for example, the following viewpoints.

[0121] [First point of view]

[0122] A position detection device for detecting the position of a displaceable detected object (10), comprising: a substrate (20) arranged opposite to the detected object; a transmitting coil (30) extending in the surface direction of the substrate; and a receiving coil (40) having a plurality of vortex parts (41), a connecting line (42), and a parallel line (43), wherein the wiring of the plurality of vortex parts is formed into a vortex shape and arranged in the displacement direction of the detected object, the plurality of vortex parts are inductively coupled by electromagnetic induction caused by the passage of electricity to the transmitting coil, the connecting line electrically connects the plurality of vortex parts to each other, and the parallel line is electrically connected to the vortex parts and the connecting line and is parallel to the connecting line.

[0123] [Second point of view]

[0124] In the position detection device as described in the first viewpoint, the connecting line and the parallel line are configured so that, in a specified instantaneous value of the alternating current applied to the transmitting coil, the direction of the current flowing through a specified portion of the connecting line and the direction of the current flowing through a specified portion of the parallel line adjacent to the specified portion of the connecting line are in opposite directions.

[0125] [Third point of view]

[0126] In the position detection device described in the first aspect, the connecting line and the parallel line are arranged adjacent to each other at a distance such that at least a portion of the magnetic field generated by the current flowing in the connecting line by the alternating current applied to the transmitting coil and at least a portion of the magnetic field generated by the current flowing in the parallel line cancel each other out.

[0127] [Fourth Viewpoint]

[0128] In the position detection device as described in the first viewpoint, the connecting line and the parallel line are configured so that, in a specified instantaneous value of the alternating current applied to the transmitting coil, the direction of the current flowing through a specified portion of the connecting line and the direction of the current flowing through a specified portion of the parallel line adjacent to the specified portion of the connecting line are opposite directions; further, the connecting line and the parallel line are configured adjacent to each other at a distance such that at least a portion of the magnetic field generated by the current flowing in the connecting line due to the alternating current applied to the transmitting coil and at least a portion of the magnetic field generated by the current flowing in the parallel line cancel each other out.

[0129] [Fifth Viewpoint]

[0130] In the position detection device described in any one of the first to fourth aspects, the connecting lines are provided at a plurality of locations between the plurality of vortex portions; and the parallel lines are provided corresponding to at least a portion or all of the plurality of connecting lines.

[0131] [Sixth Viewpoint]

[0132] In the position detection device according to any one of the first to fifth aspects, the connection lines and the parallel lines are provided on different layers of the substrate.

[0133] [Seventh Viewpoint]

[0134] In the position detection device according to any one of the first to fifth aspects, the connection lines and the parallel lines are provided on the same layer of the substrate.

[0135] [Eighth Viewpoint]

[0136] A position detection device as described in any one of the first to seventh viewpoints, wherein the receiving coil comprises: a first receiving coil (410) having a first vortex portion (411) on one side, a first vortex portion on the other side, a first connecting line (412), and a first parallel line (413), wherein the first vortex portion (411) on one side flows in a counterclockwise direction at a specified instantaneous value of an alternating current applied to the transmitting coil, and the first vortex portion on the other side flows in a clockwise direction at the specified instantaneous value, the first connecting line electrically connects the first vortex portion on one side with the first vortex portion on the other side, the parallel line is electrically connected to the first vortex portion on one side, the first vortex portion on the other side, and the first connecting line, and is parallel to the first connecting line; and a second receiving coil (420) has a second vortex portion (421) on one side, a second vortex portion on the other side, a second connecting line (422), and a second parallel line (423), wherein the second vortex portion on one side flows in a counterclockwise direction at another instantaneous value of the alternating current applied to the transmitting coil, and the second vortex portion on the other side flows in a clockwise direction at this other instantaneous value, the second connecting line electrically connects the second vortex portion on one side with the second vortex portion on the other side, the second parallel line is electrically connected to the second vortex portion on one side, the second vortex portion on the other side, and the second connecting line, and is parallel to the second connecting line. The first vortex portion on one side, the second vortex portion on one side, the first vortex portion on the other side, and the second vortex portion on the other side are arranged in this order.

[0137] [Ninth Viewpoint]

[0138] As in the position detection device described in the eighth viewpoint, for the first vortex portion of one side and the first vortex portion of the other side arranged to sandwich the second vortex portion of one side or the second vortex portion of the other side, the distance between the center of the first vortex portion of one side and the center of the first vortex portion of the other side is set so that the phases of the characteristic values ​​corresponding to the displacement of the detected body differ by 180 degrees in electrical angle; for the second vortex portion of one side and the second vortex portion of the other side arranged to sandwich the first vortex portion of one side or the first vortex portion of the other side, the distance between the center of the second vortex portion of one side and the center of the second vortex portion of the other side is set so that the phases of the characteristic values ​​corresponding to the displacement of the detected body differ by 180 degrees in electrical angle.

Claims

1. A position detection device for detecting the position of a displaceable object (10) to be detected, The position detection device comprises: A substrate (20) is arranged opposite to the object to be detected; a transmitting coil (30) extending in the surface direction of the substrate; and The receiving coil (40) has a plurality of vortex parts (41), a connecting line (42), and a parallel line (43). The wiring is formed into a spiral shape, and the plurality of vortex parts arranged in the displacement direction of the detected object are inductively coupled through electromagnetic induction caused by energizing the transmitting coil. The connecting line electrically connects the plurality of vortex parts to each other, and the parallel line is electrically connected to the vortex parts and the connecting line and is parallel to the connecting line.

2. The position detection device according to claim 1, The connecting wire and the parallel wire are configured so that, in a specified instantaneous value of the alternating current applied to the transmitting coil, the direction of the current flowing through a specified portion of the connecting wire and the direction of the current flowing through a specified portion of the parallel wire adjacent to the specified portion of the connecting wire are opposite directions.

3. The position detection device according to claim 1, The connecting wire and the parallel wire are arranged adjacent to each other at a distance such that at least a portion of a magnetic field generated by a current flowing in the connecting wire due to an alternating current applied to the transmitting coil and at least a portion of a magnetic field generated by a current flowing in the parallel wire cancel each other.

4. The position detection device according to claim 1, The connecting wire and the parallel wire are configured so that, in a specified instantaneous value of the alternating current applied to the transmitting coil, the direction of the current flowing through a specified portion of the connecting wire and the direction of the current flowing through a specified portion of the parallel wire adjacent to the specified portion of the connecting wire are opposite directions. Furthermore, the connecting wire and the parallel wire are arranged adjacent to each other at a distance such that at least a portion of a magnetic field generated by a current flowing in the connecting wire due to an alternating current applied to the transmitting coil and at least a portion of a magnetic field generated by a current flowing in the parallel wire cancel each other out.

5. The position detection device according to any one of claims 1 to 4, The connecting line is provided at a plurality of locations between the plurality of vortex portions. The parallel lines are arranged corresponding to at least a part or all of the plurality of connection lines.

6. The position detection device according to any one of claims 1 to 4, The connecting lines and the parallel lines are disposed on different layers of the substrate.

7. The position detection device according to any one of claims 1 to 4, The connecting lines and the parallel lines are arranged on the same layer of the substrate.

8. The position detection device according to any one of claims 1 to 4, The receiving coil comprises: A first receiving coil (410) comprises a first vortex portion (411) on one side, a first vortex portion on the other side, a first connecting line (412), and a first parallel line (413), wherein the first vortex portion (411) on one side flows in a counterclockwise direction at a predetermined instantaneous value of an alternating current applied to the transmitting coil, and the first vortex portion on the other side flows in a clockwise direction at a predetermined instantaneous value, the first connecting line electrically connects the first vortex portion on one side with the first vortex portion on the other side, the first parallel line electrically connects the first vortex portion on one side, the first vortex portion on the other side, and the first connecting line, and is parallel to the first connecting line; and The second receiving coil (420) comprises a second vortex portion (421) on one side, a second vortex portion on the other side, a second connecting line (422), and a second parallel line (423), wherein the current of the second vortex portion (421) on one side flows in a counterclockwise direction at another instantaneous value of the alternating current applied to the transmitting coil, and the current of the second vortex portion on the other side flows in a clockwise direction at another instantaneous value, the second connecting line electrically connects the second vortex portion on one side with the second vortex portion on the other side, the second parallel line is electrically connected to the second vortex portion on one side, the second vortex portion on the other side, and the second connecting line, and is parallel to the second connecting line, The one first vortex portion, the one second vortex portion, the other first vortex portion, and the other second vortex portion are arranged in this order.

9. The position detection device according to claim 8, For the first vortex portion of one side and the first vortex portion of the other side arranged to sandwich the second vortex portion of one side or the second vortex portion of the other side, a distance between the center of the first vortex portion of one side and the center of the first vortex portion of the other side is set so that the phase of the characteristic value corresponding to the displacement of the detected body differs by 180 degrees in electrical angle, For the second vortex portion of one side and the second vortex portion of the other side, which are arranged to sandwich the first vortex portion of one side or the first vortex portion of the other side, the distance between the center of the second vortex portion of one side and the center of the second vortex portion of the other side is set so that the phase of the characteristic value corresponding to the displacement of the detected body differs by 180 degrees in electrical angle.

Images