Displacement detection device of the electromagnetic induction type and measuring instrument using the same

Abstract

Displacement detection device (1) of the electromagnetic induction type, comprising: a scale (2) which includes a scale coil (22, 22a, 22b, 22c) arranged at a predetermined period along a measuring direction; and a head (3) which is oriented to the scale (2) and moves relative to the scale (2) in the measuring direction, the head (3) comprising: a transmitting device (4) comprising a transmitting coil (41) which generates a magnetic flux in the scale coil (22, 22a, 22b, 22c); and a receiving device (5) comprising a first receiving unit (51) and a second receiving unit (52), each receiving a change in magnetic flux from the scale coil (22, 22a, 22b, 22c), wherein the first receiving unit (51) and the second receiving unit (52) are arranged to overlap each other, and the first receiving unit (51) and the second receiving unit (52) are arranged offset from each other along the measuring direction, and Each of the first receiving unit (51) and second receiving unit (52) includes: several coil lines (511, 511a, 511b, 511c, 512, 512a, 512b, 512c) which include several receiving coils (500) arranged along a series direction parallel to the measuring direction, and wherein the multiple coil lines (511, 511a, 511b, 511c, 512, 512a, 512b, 512c) are arranged in at least three rows along a column direction in each of the first receiving unit (51) and the second receiving unit (52), wherein the multiple receiving coils (500) are arranged in the same period as a period in which the scale coils (22, 22a, 22b, 22c) are arranged along the series direction, and the receiving device (5) includes: an end section (10a) and another end section (10b) with a thinner arrangement of receiving coils (500) in at least one of the several coil lines (511, 511a, 511b, 511c, 512, 512a, 512b, 512c), each positioned on one end side and another end side respectively in the measuring direction; and a central section (11) which is positioned between one end section (10a) and the other end section (10b) and in which the density of the multiple receiving coils (500) is more densely designed.

Description

Background Technical field

[0001] The present invention relates to a displacement detection device of the electromagnetic induction type, which uses an induced current to detect the extent of movement between elements. State of the art

[0002] A displacement detection device of the electromagnetic induction type is generally known, comprising: a scale which includes a scale coil, and a head which is oriented to the scale and moves relatively along a measuring direction.

[0003] The head includes a transmitting device, which contains a transmitting coil that generates a magnetic flux in the scale coil, and a receiving device, which contains a receiving coil that receives a change in magnetic flux from the scale coil.

[0004] In such electromagnetic induction-type displacement detection devices, for example, the induction-type displacement detection device described in publication JP 2009-186348 A includes a scale comprising several magnetic flux-coupled elements (scale coils) arranged along the measurement direction, and a sensor head (head) oriented to the scale and moving relative to the measurement direction. The sensor head includes a transmitting winding (transmitting coil) that directs the magnetic flux to the several magnetic flux-coupled elements, and a receiving winding (receiving coil) capable of magnetic flux coupling with the several magnetic flux-coupled elements.

[0005] The receiving winding comprises a first wiring layer containing several wires, essentially in the shape of an S, arranged in series parallel to the measuring direction, and a second wiring layer containing several wires, essentially in the shape of an inverted S, arranged in series in a similar manner to the first wiring layer. In the receiving winding, the first and second wiring layers are stacked, forming several rectangular windings.The receiving winding comprises a winding group containing multiple windings arranged in series. Two rows of winding groups are arranged along a column perpendicular to the series direction on a surface upon which the first and second wiring layers are also arranged. The receiving winding includes the two rows of winding groups arranged along the column direction, thereby improving the received signal strength.

[0006] Publication JP 2003-121206A describes a configuration in which a first and a second scale winding, arranged in different periods, are connected by a connecting wire. The connecting wire comprises two conductive lines arranged parallel to each other. The connecting wire is set to the same length at each position, thus compensating for the received signal level, which is attenuated by the current flowing in opposite directions in the two conductive lines.

[0007] Publication JP 2006-017533A describes an electromagnetic induction position sensor. This sensor is equipped with an alternating current magnetic flux generator for producing an alternating current magnetic flux with a wavelength of essentially λ and a plurality of coils for receiving the magnetic flux to output electromagnetically induced voltages. One of the coils comprises eight conductor tracks with sinusoidal waveforms of different wavelengths, each arranged on an even number of layers, with insulating material between them. The plurality of conductor tracks on the same layer are spaced apart in the amplitude direction of the sinusoidal waveforms, while being located at the same position as the plurality of conductor tracks on another adjacent layer.The amplitude is out of phase with the numerous conductor patterns formed on the other adjacent layer. The eight conductor patterns are connected in series, so that the conductor patterns on the adjacent layers and the direction of an electric current appear opposite to each other when viewed from the front of a sensor substrate.

[0008] Publication JP 2004 - 354 303 A describes a configuration in which the cross-sectional areas of paired coil elements arranged at equal distances from the center of a receiving coil are adjusted so that the centers of gravity of the coil cross-sections of the two coil elements coincide with the center position of a central receiving coil. The sums of the coil cross-sectional areas of the paired coil elements are equalized in the receiving coils.

[0009] Publication JP 2005 - 077 150 A describes a configuration in which the direction of movement (measuring axis) of a sensor head is inclined relative to the direction of extension of tracks running parallel to a scale. The intensity of the signal received by a receiving coil thus changes with the movement of the sensor head. The signal intensity is correlated with the position of the sensor head to measure the position.

[0010] Document US 7,015,687 B2 describes an inductive position sensor. The position sensor comprises a scale with a series of conductor loops spaced [missing information] and a cursor equipped with conductors, each forming a series of alternating hairpin turns. The inducing and induced cursor conductors are arranged in two separate, interlocking groups of conductors, with the coupling between the inducing and induced conductors of the second group occurring solely through the scale loops. Summary of the invention; Problems to be solved by the invention

[0011] There are cases where the head is tilted in a roll direction, a pitch direction and a yaw direction with respect to the scale, which causes a problem in that the change in the magnetic flux received by the receiving device is affected.

[0012] Here, the roll direction is a direction in which the head rotates around the row direction; the pitch direction is a direction in which the head rotates around the column direction; and the yaw direction is a direction in which the head rotates around a direction perpendicular to the row direction and the column direction.

[0013] For example, if the head rotates in the direction of pitch relative to the scale and one end approaches the scale along the row direction, the other end moves away from the scale. In this case, the influence of the change in the received magnetic flux increases at one end of the receiving device, while at the other end of the receiving device, the influence of the change in the received magnetic flux decreases.

[0014] Conversely, if the head rotates, for example, in the direction of pitching relative to the scale, and one end moves away from the scale along the row direction, the other end moves closer to the scale. In this case, the influence of the change in the received magnetic flux decreases at one end of the receiving device, while the influence of the change in the received magnetic flux increases at the other end of the receiving device.

[0015] One object of the present invention is to provide a displacement detection device of the electromagnetic induction type, in which the influence of the change in the magnetic flux received by the receiving device can be counteracted. Means of solving the problems

[0016] According to the present invention, a displacement detection device of the electromagnetic induction type comprises: a scale including a scale coil; and a head oriented to the scale and moving relative to the scale in a measuring direction, the head comprising: a transmitting device including a transmitting coil which generates a magnetic flux in the scale coil;and a receiving device comprising a first receiving unit and a second receiving unit, each receiving a change in magnetic flux from the scale coil, and in which the first receiving unit and the second receiving unit are arranged offset from each other along the measuring direction, and wherein the first receiving unit and the second receiving unit comprise: several coil lines arranged parallel along a column direction, wherein the several coil lines comprise several receiving coils arranged parallel to the measuring direction along a series direction, and the receiving device comprises: an end section and another end section positioned on one end side and another end side respectively in the measuring direction, and in which the density of the several receiving coils is designed to be thinner;and a central section positioned between one end section and the other end section, in which the density of the multiple receiving coils is denser.

[0017] Here, a condition in which the density of the multiple receiving coils is reduced, for example, a condition in which the number of turns of the receiving coils is decreased, wherein a section not acting as a receiving coil is not provided for generating the magnetic flux, or in which the area of ​​the receiving coils is reduced, thereby making the device less sensitive to the influence of the magnetic flux received from the receiving device. Additionally, a condition in which the density of the multiple receiving coils is reduced, for example, a condition in which the number of turns is increased by overlapping the receiving coils or in which the area of ​​the receiving coils is increased, thereby making the device more sensitive to the influence of the magnetic flux received from the receiving device.

[0018] According to the present invention as described above, even when the head rotates in the direction of pitching and moves close to or further away from the scale, the change in the generated magnetic flux in one end section and the other end section, in which the density of the multiple receiving coils is thinner, is smaller compared to the central section, in which the density of the multiple receiving coils is denser, thereby making it possible to make the device less sensitive to the influence of changes in the magnetic flux received by the receiving device.

[0019] Furthermore, even when the head rotates in the direction of pitch and moves closer to or further away from the scale, the magnitude of the generated magnetic flux in the central section, where the density of the multiple receiving coils is higher, is greater compared to the two end sections, where the density of the multiple receiving coils is lower. This makes it possible to make the device more sensitive to changes in the magnetic flux received by the receiving device. As a result, the change in the magnetic flux received by the receiving device can be stabilized in the electromagnetic displacement detection device.

[0020] Therefore, in the displacement detection device of the electromagnetic induction type, the influence of the change in the magnetic flux received by the receiving device can be counteracted.

[0021] In the present case, it is preferred if the density of the multiple receiving coils in one end section and the other end section is made thinner by removing some of the receiving coils from the multiple coil lines in at least one coil line.

[0022] In this case, the receiving coils are designed in such a way that several wiring layers, in which several wiring lines are formed, are stacked on a substrate.

[0023] By a method for stacking at least three wiring layers, it is possible, for example, to achieve a state in which the receiving coils are in a lower density. In particular, a method can be used in which, in addition to the two wiring layers forming the receiving coils, a new wiring layer is added, which includes a wiring line for neutralizing the functions of the receiving coils. In this case, a problem arises in that the receiving coils must be formed by stacking at least three wiring layers.

[0024] Furthermore, the method of stacking at least three wiring layers can, for example, result in the receiving coils being in a state where the density of the multiple coils is increased. In particular, a method can be used in which, in addition to the two wiring layers forming the receiving coils, a third wiring layer is stacked, which includes a wiring line for connecting the two wiring layers to increase the number of turns. In this case, a problem arises in that the receiving coils must be formed by stacking at least three wiring layers.

[0025] According to the present invention, however, one end section and the other end section are each in a state in which the density of the multiple receiving coils is reduced by removing some of the receiving coils from at least one coil line. Therefore, without having to stack the wiring layer to neutralize the functions of the receiving coils or the wiring layer to connect the two wiring layers to increase the number of turns, the receiving coils can be formed by stacking the two wiring layers in a state in which the density of the multiple receiving coils is reduced and in a state in which the density is increased.

[0026] Since the receiving coils are formed by stacking the two wiring layers, the number of wiring layers used is also smaller than in a case where three wiring layers are stacked to form the receiving coil. Therefore, the manufacturing process of the receiving coils can be simplified, and a cost reduction can be achieved in an electromagnetic induction displacement detection device.

[0027] In a case where several receiving units, such as the first and second receiving units, are arranged offset from one another, the receiving coils can be configured in a state where the density of the multiple receiving coils is reduced by using two wiring layers instead of three. Specifically, the multiple effective receiving coils are spaced apart along the measuring direction and are configured in a state where the density of the multiple receiving coils is reduced. Furthermore, a method can be employed in which the wiring is arranged to extend into a region outside the area where the effective receiving coils are located, and the multiple receiving coils, which are spaced apart from one another, are interconnected.Since the receiving coils in this case are arranged such that the wiring extends outside the area where the effective receiving coils are located, a problem arises in that the area required to form the receiving coils increases. Furthermore, a problem arises in that a wiring line, which does not act as one of the receiving coils, must be used to connect the several spaced-apart receiving coils.

[0028] According to the present invention, one end section and the other end section are each in a state in which the density of the multiple receiving coils is reduced by removing some of the receiving coils. Therefore, the receiving coils can be in a state with a reduced density without the wiring line extending outside the area where the effective receiving coils are located. Additionally, without using the wiring line that does not act as one of the receiving coils to connect the multiple spaced-apart receiving coils, all wiring lines can be effectively configured as receiving coils.Therefore, the efficiency of the receiving coils can be improved in the electromagnetic type displacement detection device.

[0029] In the present case, it is preferred if the first receiving unit and the second receiving unit include three or more rows of coil lines, wherein in one end section and the other end section the density of the multiple receiving coils is made thinner by removing some of the receiving coils of each of the coil lines, which are arranged on both sides in the column direction, from the multiple coil lines in an axially symmetrical manner with respect to an axis of symmetry along the measuring direction.

[0030] In the present embodiment, in one end section and the other end section, some of the receiving coils of each of the multiple coil lines, arranged on both sides in the direction of the column, are axially symmetrical along the measuring direction with respect to the axis of symmetry. As a result, when the head rotates in the rolling direction with respect to the scale, the number of multiple receiving coils close to the scale and the number of receiving coils farther from the scale are mutually equal in both end sections, thus neutralizing and reducing the influence of changes in magnetic flux.

[0031] In the present case, it is preferred if the density of the multiple receiving coils in one end section and the other end section is made thinner by removing an identical number of receiving coils.

[0032] In the present embodiment, the multiple receiving coils of the receiving device are arranged along the measuring direction in a substantially hexagonal shape. In particular, in a state where the density of the multiple receiving coils is denser, sections are arranged in a substantially rectangular shape. In a state where the density of the multiple receiving coils is less dense, sections are arranged in a substantially triangular shape, with each side forming the base of the substantially rectangular shape on the side corresponding to one end section and the side corresponding to the other end section. As a result, when the head rotates in the yaw direction with respect to the scale, the receiving coils in one end section and the other end section do not protrude beyond the scale, thus reducing the influence of changes in magnetic flux.

[0033] A measuring instrument of the present invention includes a displacement detection device of the electromagnetic induction type according to the present invention, wherein a measurement result is output based on the extent of a movement occurring between a scale and a head, which is detected by the displacement detection device of the electromagnetic induction type.

[0034] According to the present invention as described above, the measuring instrument includes the displacement detection device of the electromagnetic induction type according to the present invention, wherein the influence of the change in the magnetic flux received by the receiving device is counteracted and the stability of the measurement result can be improved. Brief description of the drawing Fig. Figure 1 is a perspective view illustrating a displacement detection device of the electromagnetic induction type according to a first embodiment of the present invention. Fig. Figure 2 is a top view showing a scale according to the first embodiment of the present invention. Fig. Figure 3 is a top view illustrating a head according to the first embodiment of the present invention. Fig. Figures 4A to 4C are diagrams illustrating a receiving unit according to the first embodiment of the present invention. Fig. 5A and Fig. Figure 5B are diagrams illustrating wiring lines forming receiving coils according to the first embodiment of the present invention. Fig. Figure 6 is a top view illustrating a head according to a second embodiment of the present invention. Fig. Figure 7 is a diagram illustrating a receiving unit according to a modification. Detailed description of the embodiments: First embodiment

[0035] A first embodiment of the present invention is described below with reference to the drawing.

[0036] Fig. Figure 1 is a perspective view illustrating a displacement detection device of the electromagnetic induction type according to the first embodiment of the present invention.

[0037] As in Fig. As shown in Figure 1, a displacement detection device 1 of the electromagnetic induction type includes a scale 2 which includes a scale coil and a head 3 which is oriented to the scale 2 and moves relatively along a measuring direction, and is used as a measuring instrument for an electromagnetic induction type caliper.

[0038] The electromagnetic induction displacement detection device 1 is provided within the electromagnetic induction caliper. Within the electromagnetic induction caliper, the scale 2 and the head 3 are moved relative to each other along the X-direction, which is the measuring direction. The extent of the movement between the elements is detected by the electromagnetic induction displacement detection device 1 based on an induced current, and the measurement result is displayed on a display unit (not shown) or the like, based on the extent of the detected movement.

[0039] In the following description and in the drawing figures, cases are dealt with in which the direction of movement (measuring direction) of the head 3, which is the longitudinal direction of the scale 2, is referred to as the X-direction, while the width direction of the scale 2 perpendicular to the X-direction is referred to as the Y-direction.

[0040] Fig. Figure 2 is a top view showing the scale according to the first embodiment of the present invention.

[0041] As in Fig. As shown in Figure 2, the scale 2 includes an insulating substrate 21 consisting of an elongated glass epoxy resin and a scale coil 22 which is oriented towards the head 3.

[0042] The insulating substrate 21 can also consist of a material such as glass or silicon instead of the glass epoxy resin.

[0043] The scale coil 22 is made of a material with low electrical resistance, such as aluminium, copper or gold, and is formed by an essentially rectangular linear conductor having a width W in the X direction.

[0044] The scale coil 22 is provided with the same grid width (pitch) W as the width W of the scale coil 22 along the X-direction on the scale 2, with three rows provided along the Y-direction. Consequently, the scale coil 22 comprises a scale coil 22a of the first row, a scale coil 22b of the second row, and a scale coil 22c of the third row. Additionally, the scale coil 22 can be a metal plate with a periodic arrangement or the like, instead of being configured as a linear conductor.

[0045] Fig. Figure 3 is a top view illustrating the head according to the first embodiment of the present invention.

[0046] As in Fig. As shown in Figure 3, the head 3 on an insulating substrate 31 made of glass epoxy resin includes a transmitter 4 which generates a magnetic flux in the scale coil 22 (see Figure 3). Fig. 2) generated, and a receiving device 5 that receives a change in magnetic flux from the scale coil 22. The insulating substrate 31 can be made of a material such as glass or silicon instead of glass epoxy resin.

[0047] The transmitting device 4 is designed to be oriented towards the scale 2 and includes a transmitting coil 41 which generates the magnetic flux in the scale coil 22.

[0048] The transmitting coil 41 is made of a material with low electrical resistance, such as aluminium, copper or gold, and is arranged in a rectangular shape so that it surrounds the receiving device 5.

[0049] However, the transmitting coil 41 does not have to be arranged in a rectangular shape so that it surrounds the receiving device 5, but can have any configuration as long as the magnetic flux can be generated in the scale coil 22.

[0050] The receiving device 5 is positioned inside the transmitting coil 41 and includes receiving units 51 to 53, which contain several receiving coils 500. Receiving unit 51 acts as the first receiving unit, while receiving unit 52 acts as the second receiving unit. The receiving units 51 to 53 are arranged such that the phases of the three units are shifted by 120° relative to each other.

[0051] In a case where any two of the receiving units 51 to 53 are arranged such that the phases of the two units are shifted relative to each other, the receiving device 5 can detect the direction of movement (signal direction) of the head 3 with respect to the scale 2. In a case where the receiving units 51 to 53 are arranged such that the phases of the three units are shifted relative to each other, the receiving device 5 can extract a two-phase signal from a three-phase signal and neutralize the distortion of a signal that is generated when the head 3 is moved relative to the scale 2.

[0052] To improve the accuracy of the signal to be detected, for the same reason, the three receiving units 51 to 53 of the receiving device 5, i.e., the receiving unit 51 as the first receiving unit, the receiving unit 52 as the second receiving unit and the additional receiving unit 52, are arranged offset from each other along the X-direction, which is the measuring direction.

[0053] The receiving device 5 comprises an end section 10a and another end section 10b, which are positioned on one end side (side facing left of the sheet) and on the other end side (side facing right of the sheet) respectively in the X-direction, which is the measuring direction, wherein the density of the multiple receiving coils 500 is designed to be lower. Additionally, the receiving device 5 comprises a central area 11, which is positioned between one end section 10a and the other end section 10b and in which the density of the multiple receiving coils 500 is designed to be higher.

[0054] One end section 10a and the other end section 10b are thinner sections in which the receiving units 51 to 53 are arranged offset from one another and in which the overlap of the multiple receiving coils 500 is smaller than that in the central section 11, wherein the multiple receiving coils 500 are arranged in a substantially triangular shape.

[0055] The central section 11 is a more densely designed section in which the receiving units 51 to 53 are arranged offset from one another and in which the overlap of the multiple receiving coils 500 is greater than in one end section 10a and the other end section 10b, wherein the multiple receiving coils 500 are arranged in a substantially rectangular shape.

[0056] Therefore, the multiple receiving coils 500 of the receiving device 5 are arranged in an elongated, essentially hexagonal shape along the X-direction, which is a series direction.

[0057] Fig. Figures 4A to 4C are diagrams illustrating the receiving unit according to the first embodiment of the present invention.

[0058] In particular, Fig. 4A a diagram to illustrate the receiving unit 51, which is the first receiving unit. Fig. 4B is a diagram illustrating the receiver unit 52, which is the second receiver unit. Fig. 4C is a diagram illustrating the receiver unit 53.

[0059] The receiving units 51 to 53 each include coil lines 511 to 513 in which the several receiving coils 500 are arranged parallel to the measuring device along the X-direction, which is the series direction.

[0060] Three rows of each of the coil lines 511 to 513 in the receiving units 51 to 53 are arranged parallel along the Y direction, which is the column direction.

[0061] As in Fig. As shown in Figure 4A, the receiving unit 51 includes the coil line 511, in which the several receiving coils 500 are arranged along the X direction.

[0062] The coil line 511 includes a coil line 511a positioned in the top row (direction upwards on the sheet), a coil line 511b positioned in the middle row, and a coil line 511c positioned in the bottom row (direction downwards on the sheet), with the coil lines arranged parallel along the Y direction.

[0063] In one end section 10a of the receiving unit 51, two of the receiving coils 500, which are arranged on both sides in the Y-direction, are removed axially symmetrically with respect to an axis of symmetry L1 along the X-direction, which is the measuring direction, from the coil lines 511a and 511c.

[0064] As in Fig. As shown in Figure 4B, the receiving unit 52 includes a coil line 512 in which the several receiving coils 500 are arranged along the X direction.

[0065] The coil line 512 includes a coil line 512a positioned in the top row, a coil line 512b positioned in the middle row, and a coil line 512c positioned in the bottom row, with the coil lines arranged parallel along the Y direction.

[0066] In the other end section 10b of the receiving unit 52, two of the receiving coils 500, which are arranged on both sides in the Y direction, are axially symmetrical with respect to the axis of symmetry L1 along the X direction from each of the coil lines 512a and 512c.

[0067] Consequently, in the receiving unit 52 the receiving coils 500 are arranged at positions in which the receiving unit 51 is inverted axially symmetrically with respect to an axis of symmetry L2 along the Y-direction, which is the column direction.

[0068] As in Fig. As shown in Figure 4C, the receiving unit 53 includes a coil line 513 in which the several receiving coils 500 are arranged along the X direction.

[0069] The coil line 513 includes a coil line 513a positioned in the top row, a coil line 513b positioned in the middle row, and a coil line 513c positioned in the bottom row, with the coil lines arranged parallel along the Y direction.

[0070] In one end section 10a and the other end section 10b of the receiving unit 53, one of the receiving coils 500, which are arranged on both sides in the Y direction, which is the column direction, is removed from the coil lines 513a and 513c in an axially symmetrical manner with respect to the axis of symmetry L1 along the X direction, which is the measuring direction.

[0071] Consequently, in the receiving unit 53 the receiving coils 500 are arranged at positions which are axially symmetrical with respect to the axes of symmetry L1 and L2 along the X and Y directions.

[0072] Fig. 5A and Fig. Figure 5B are diagrams illustrating wiring lines forming receiving coils according to the first embodiment of the present invention.

[0073] In particular, Fig. 5A and Fig. 5B Diagrams each for the representation of several wiring lines 6, which connect the receiving coils 500 in the receiving unit 51 of Fig. 4A form. In addition, the multiple wiring layers 6 include a first wiring layer 61 and a second wiring layer 62, each containing several arranged wiring leads. Fig. 5A is a diagram illustrating the first wiring layer 61. Fig. 5B is a diagram illustrating the second wiring layer 62.

[0074] The receiving coils 500 are formed by stacking the first wiring layer 61 and the second wiring layer 62.

[0075] As in Fig. As shown in Figure 5A, the first wiring layer 61 essentially comprises S-shaped wiring lines 611, which form the receiving coils 500 of the central section 11, which is a denser section of the receiving unit 51, and wiring lines 612, which form the receiving coils 500 of one end section 10a, which is a thinner section of the receiving unit 51, along the X-direction, which is the measuring direction.

[0076] As in Fig. As shown in Figure 5B, the second wiring layer 62 essentially comprises wiring lines 621 having the shape of an inverted S, which form the receiving coils 500 of the central section 11, which is the denser section of the receiving unit 51, and wiring lines 622, which form the receiving coils 500 of one end section 10a, which is the thinner section of the receiving unit 51, along the X-direction, which is the measuring direction.

[0077] The multiple wiring layers 6 include connecting sections 7, which form the receiving coils 500 by stacking and connecting the first wiring layer 61 and the second wiring layer 62. The connecting sections 7 continuously connect the first wiring layer 61 and the second wiring layer 62.

[0078] In particular, they include, as in Fig. 5A and Fig. As shown in Figure 5B, the connecting sections 7 comprise a first connecting section 7a up to an eighteenth connecting section 7r. The first connecting section 7a up to the third connecting section 7c, the seventeenth connecting section 7q, and the eighteenth connecting section 7r form the wiring lines 611 and the wiring lines 621 for forming the receiving coils 500 of one end section 10a, which is the thinner section of the receiving unit 51. The fourth connecting section 7d up to the sixteenth connecting section 7p connect the wiring lines 611 and the wiring lines 621 to form the receiving coils 500 of the central section 11, which is the denser section of the receiving unit 51.

[0079] The several wiring layers 6 are continuously connected to each other through the first connection section 7a to the eighteenth connection section 7r, so that a current flows, for example, from the first connection section 7a as the starting point to the first connection section 7a as the endpoint, with the wiring layers 6 acting as a whole as a receiving unit 51, which represents a coil.

[0080] The starting point and the end point of the current flow are not limited to the first connecting section 7a, but any of the connecting sections 7 from the first connecting section 7a to the eighteenth connecting section 7r can be the starting point and end point.

[0081] The wiring layers 6 of the receiving unit 52 have an arrangement that is identical to that in which the wiring layers 6 of the receiving unit 51 are inversely axially symmetric with respect to the axis of symmetry L2.

[0082] In addition, the receiving unit 53 (not shown) is formed throughout by stacking the first wiring layer and the second wiring layer and connecting the layers to each other through the connecting sections 7 similar to the receiving units 51 and 52.

[0083] The connecting sections 7 are each a through hole, a via hole or the like and can have any configuration, as long as the receiving coils 500 can be formed by connecting the wiring lines 611, 612, 621 and 622.

[0084] According to the present embodiment as described above, the following functions and effects can be achieved.

[0085] (1) Even when the head 3 rotates in the direction of pitching and comes close to or away from the scale 2, the change in the generated magnetic flux in one end section 10a and the other end section 10b, where the density of the multiple receiving coils 500 is thinner, is smaller than in the central section 11, where the density of the multiple receiving coils 500 is denser, making it possible to make the device less sensitive to the influence of a change in the magnetic flux received by the receiving device 5.Furthermore, even when the head 3 rotates in the tilting direction and approaches and moves away from the scale 2, the magnitude of the generated magnetic flux in the central section 11, where the density of the multiple receiving coils 500 is higher, is greater than in one end section 10a and the other end section 10b, where the density of the multiple receiving coils 500 is lower. This makes it possible to make the device more sensitive to changes in the magnetic flux received by the receiving device 5. As a result, the change in the magnetic flux received by the receiving device 5 can be stabilized in the electromagnetic induction displacement detection device 1.Therefore, in the displacement detection device 1 of the electromagnetic induction type, the influence of a change in the magnetic flux received by the receiving device 5 can be counteracted.

[0086] (2) One end section 10a and the other end section 10b are each in a state in which the density of the multiple receiving coils 500 is reduced by the fact that some of the receiving coils 500 are located away from the multiple coil lines 511 to 513 in at least one coil line. Therefore, without the wiring layer for neutralizing the function of the receiving coils 500 or the wiring layer for connecting the two wiring layers 61 and 62 to increase the number of turns being added, the receiving coils 500 can be formed by stacking the two wiring layers 61 and 62 in a state in which the density of the multiple receiving coils 500 is reduced and in a state in which the density is increased.

[0087] (3) Since the receiving coils 500 are formed by stacking the two wiring layers 61 and 62, the number of wiring layers used is smaller than in a case where three wiring layers are stacked to form the receiving coils 500. Therefore, the manufacturing process of the receiving coils 500 is simpler, and a cost reduction can be achieved in electromagnetic displacement detection devices 1. (4) The receiving coils 500 may be in a state in which the density of the multiple receiving coils 512 is designed to be thinner, without the need for the wiring line extending outside the area in which the effectively operating receiving coils 500 are formed. (5) In the case of the receiving coils 500, it is possible to ensure that all wiring lines effectively act as receiving coils 500. Therefore, the efficiency of the receiving coils 500 in the electromagnetic induction displacement detection device 1 can be improved. (6) In one end section 10a and the other end section 10b, some of the receiving coils 500 of each of the multiple coil lines 511 to 513, which are arranged on both sides in the column direction, are axially symmetrical with respect to the axis of symmetry L1 along the measuring direction. As a result, in a case where the head 3 rotates in the rolling direction with respect to the scale 2, in one end section 10a and the other end section 10b, the number of multiple receiving coils 500 close to the scale 2 and the number of receiving coils 500 farther from the scale 2 are mutually equal, so that the influence of a change in magnetic flux can be neutralized and reduced. (7) The multiple receiving coils 500 of the receiving device 5 are arranged in a substantially hexagonal shape along the measuring direction. In particular, sections in a state where the density of the multiple receiving coils 500 is denser are arranged in a substantially rectangular shape. Sections in a state where the density of the multiple receiving coils 500 is less dense are arranged in a substantially triangular shape, with each side on the side of the substantially rectangular shape adjacent to one end section 10a and the other end section 10b as their base. As a result, when the head 3 rotates in the yaw direction with respect to the scale 2, the receiving coils 500 in one end section 10a and the other end section 10b do not readily protrude beyond the scale, thus reducing the influence of a change in magnetic flux. (8) The measuring instrument includes the displacement detection device 1 of the electromagnetic induction type according to the present invention, which counteracts the influence of a change in the magnetic flux received by the receiving device 5 and improves the stability of the measurement result. Second embodiment

[0088] A second embodiment of the present invention is described below with reference to the drawing. In the following description, parts already described are designated with the same reference numerals, and a further description of them is omitted.

[0089] Fig. Figure 6 is a top view illustrating the head according to the second embodiment of the present invention.

[0090] Apart from a receiving device 5A, the head 3A of the present embodiment has essentially the same design as the head 3 of the first embodiment.

[0091] As in Fig. As shown in Figure 3, the receiving device 5 of the first embodiment comprises three receiving units 51 to 53, namely receiving unit 51 as the first receiving unit, receiving unit 52 as the second receiving unit, and the additional receiving unit 53, which are arranged offset from one another along the X-direction, which is the measuring direction. As shown in Fig. As shown in Figure 6, the receiving unit 5A of the present embodiment differs from that of the first embodiment in that the receiving unit 5A includes two receiving units 51 and 52, namely the receiving unit 51 as the first receiving unit and the receiving unit 52 as the second receiving unit, which are arranged offset from each other along the X-direction, which is the measuring direction.

[0092] The receiving device 5A can detect a direction of movement (signal direction) of the head 3 with respect to the scale 2 by arranging the two receiving units 51 and 52 such that the phases of the two units are shifted relative to each other.

[0093] In the present embodiment as described above, the functions and effects according to (1) to (8) can also be achieved in accordance with the first embodiment. Furthermore, the following function and effect can be achieved.

[0094] (9) In the receiving device 5a, the two receiving units 51 and 52, namely receiving unit 51 as the first receiving unit and receiving unit 52 as the second receiving unit, are arranged offset from each other along the X-direction, so that the number of receiving units used is smaller than in a case where three receiving units 51 to 53 are arranged offset from each other along the X-direction. Therefore, the manufacturing process of the receiving device 5a is simpler, and a cost reduction can be achieved. Modification of the embodiment

[0095] The present invention is not limited to the embodiments described above. Modifications and improvements within the scope of the problem to be solved by the present invention are included in the present invention.

[0096] In the embodiments described above, the electromagnetic induction displacement detection device 1 is used as a measuring instrument, for example, in a caliper. However, the device can also be used in other measuring instruments, such as a dial gauge (test indicator) and a micrometer. Consequently, the electromagnetic induction displacement detection device 1 is not subject to any specific limitations with regard to the type and method of the measuring instrument to be used and can also be used with other measuring instruments and the like, wherein the instrument in which the electromagnetic induction displacement detection device of the present invention is implemented is not subject to any specific limitations.

[0097] In addition, the displacement detection device 1 of the electromagnetic induction type can also be used for a device beyond a measuring instrument, for example in the case of a sensor.

[0098] In the first embodiment, receiver 51 acts as the first receiver, while receiver 52 acts as the second receiver. However, receiver 53 can also be the first receiver, or receiver 51 can be the second receiver. Consequently, for the first and second receivers, it is sufficient if any of the receivers 51 to 53 act as the first and second receivers, respectively.

[0099] Fig. Figure 7 is a diagram illustrating a receiving unit according to a modification.

[0100] As in Fig.As shown in Figure 7, a receiving unit 54 is designed such that the receiving coils 500 are not removed.

[0101] In the embodiments described above, the receiving units 51 to 53 are arranged offset from one another along the X-direction, which is the measuring direction. Receiving units having arrangements of the receiving coils 500 that differ from those of the receiving coils 500 of receiving units 51 to 53 can also be arranged offset from one another. Furthermore, the receiving unit 54, which is configured such that the receiving coils 500 are not removed, and the receiving units 51 to 53 can be combined and arranged offset from one another along the X-direction, which is the measuring direction. Therefore, it is sufficient if a state in which the density of the multiple receiving coils 500 is lower and a state in which the density is higher can be achieved by offsetting the multiple receiving units from one another in the X-direction.

[0102] In the embodiments described above, one end section 10a and the other end section 10b are arranged axially symmetrically with respect to both the X-direction, which is the measuring direction, and the Y-direction, which is the direction perpendicular to the measuring direction. However, one end section 10a and the other end section 10b can also be asymmetrical. Consequently, it is sufficient if one end section 10a and the other end section 10b are in a state in which the density of the multiple receiving coils 500 is lower compared to the central section 11.

[0103] In the embodiments described above, the density of the multiple receiving coils 500 in one end section 10a and the other end section 10b is reduced by removing an identical number of receiving coils 500. However, the density of the multiple receiving coils 500 in one end section 10a and the other end section 10b can also be reduced by removing different numbers of receiving coils 500. Therefore, it is sufficient if the density of the multiple receiving coils 500 in one end section 10a and the other end section 10b can be reduced by removing the receiving coils 500. Commercial applicability

[0104] As described above, the present invention can be used appropriately for a displacement detection device of the electromagnetic induction type, which uses an induced current to detect the extent of a movement between elements.

Claims

[1] Displacement detection device (1) of the electromagnetic induction type, comprising: a scale (2) comprising a scale coil (22, 22a, 22b, 22c) arranged at a predetermined period along a measurement direction; and a head (3) oriented to the scale (2) and moving relative to the scale (2) in the measurement direction, the head (3) comprising: a transmitting device (4) comprising a transmitting coil (41) which generates a magnetic flux in the scale coil (22, 22a, 22b, 22c); and a receiving device (5) comprising a first receiving unit (51) and a second receiving unit (52), each receiving a change in magnetic flux from the scale coil (22, 22a, 22b, 22c), wherein the first receiving unit (51) and the second receiving unit (52) are arranged to overlap each other, and the first receiving unit (51) and the second receiving unit (52) are arranged offset from each other along the measuring direction, and Each of the first receiving unit (51) and second receiving unit (52) includes: several coil lines (511, 511a, 511b, 511c, 512, 512a, 512b, 512c) which include several receiving coils (500) arranged along a series direction parallel to the measuring direction, and wherein the multiple coil lines (511, 511a, 511b, 511c, 512, 512a, 512b, 512c) are arranged in at least three rows along a column direction in each of the first receiving unit (51) and the second receiving unit (52), wherein the multiple receiving coils (500) are arranged in the same period as a period in which the scale coils (22, 22a, 22b, 22c) are arranged along the series direction, and the receiving device (5) includes: an end section (10a) and another end section (10b) with a thinner arrangement of receiving coils (500) in at least one of the several coil lines (511, 511a, 511b, 511c, 512, 512a, 512b, 512c), each positioned on one end side and another end side respectively in the measuring direction; and a central section (11) which is positioned between one end section (10a) and the other end section (10b) and in which the density of the multiple receiving coils (500) is more densely designed. [2] Displacement detection device (1) of the electromagnetic induction type according to claim 1, wherein in one end section (10a) and the other end section (10b) the density of the multiple receiving coils (500) is made thinner by removing some of the receiving coils (500) in at least one coil line from the multiple coil lines (511, 511a, 511b, 511c, 512, 512a, 512b, 512c). [3] Displacement detection device (1) of the electromagnetic induction type according to claim 2, wherein the first receiving unit (51) and the second receiving unit (52) include three or more rows of coil lines (511, 511a, 511b, 511c, 512, 512a, 512b, 512c), and In one end section (10a) and the other end section (10b), the density of the multiple receiving coils (500) is made thinner by removing some of the receiving coils (500) of each of the coil lines (511, 511a, 511b, 511c, 512, 512a, 512b, 512c), which are arranged on both sides in the column direction, from the multiple coil lines (511, 511a, 511b, 511c, 512, 512a, 512b, 512c) in an axially symmetric manner with respect to an axis of symmetry (L1, L2) along the measuring direction. [4] Displacement detection device (1) of the electromagnetic induction type according to claim 3, wherein in one end section (10a) and the other end section (10b) the density of the multiple receiving coils (500) is made thinner by removing an identical number of receiving coils (500). [5] Measuring instrument comprising a displacement detection device (1) of the electromagnetic induction type according to any one of claims 1 to 4, wherein a measurement result is output based on the extent of a movement occurring between the scale (2) and the head (3) which is detected by the displacement detection device (1) of the electromagnetic induction type.

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