JP2016217754A - Position detection device and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To highly accurately position magnetic sensors with respect to magnetic scales of position detection devices.SOLUTION: A position detection device 1 is a magnet-type linear encoder, and a sensor holder 30 holding a magnetic sensor 40 is anchored to a slide member 20 slidably assembled to a magnetic scale 10. The magnetic sensor 40 has a positioning mark 43 provided on a base plate 41 having a magnetic resistance element 42 formed. In manufacturing of the position detection device 1, as visually checking the positioning mark 43 using an optical system 60, the positioning mark 43 is positioned with respect to a positioning reference 63 appearing in a field of view 61 of the optical system 60. Thus, with respect to the magnetic scale 10, the magnetic sensor 40 can be highly accurately positioned.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a position detection device that relatively moves a magnetic sensor along a surface of a magnetic scale.

  A magnetic linear encoder (position detection device) has a slide member on which a magnetic sensor is mounted so as to be relatively movable along a magnetic scale on which tracks in which N poles and S poles are alternately arranged in a straight line are formed. The slide member is connected directly or indirectly to the position detection target object, and the position of the position detection target object is detected based on the detection signal from the magnetic sensor. In this type of magnetic linear encoder, the magnetic sensor is opposed to the track forming surface of the magnetic scale with a slight gap. The target detection accuracy can be obtained by accurately positioning the magnetic sensor with respect to the track of the magnetic scale.

  Patent Document 1 discloses a position detection device having this type of structure. The position detection device of Patent Document 1 includes a scale portion on which a position signal is recorded and a substrate that can move relative to the scale portion. A sensor holder is mounted on the substrate, and the sensor is held by the sensor holder. An adjustment member (screw) that presses the sensor holder toward the scale portion is provided on the substrate. The sensor is positioned with respect to the scale portion via the adjustment member and the sensor holder.

Japanese Patent No. 4005472

  In a position detection device such as a magnetic linear encoder, it is difficult to accurately position a sensor with respect to a position signal such as a track formed on a scale. For example, when the sensor is held by the sensor holder and the sensor holder is positioned with respect to the scale via the adjustment member or the like, the error increases due to accumulation of dimensional errors of a plurality of members. Further, when a pressing jig is used, a positional shift occurs due to release from the pressing state by the pressing jig after positioning. Therefore, it is difficult to finally perform precise positioning.

  In view of these points, an object of the present invention is to propose a position detection device that can accurately position a magnetic sensor with respect to a magnetic scale, and a manufacturing method thereof.

  In order to solve the above-described problems, a position detection device according to the present invention includes a magnetic scale including tracks in which N poles and S poles are alternately arranged in a straight line, a substrate having a positioning mark, and the substrate. It has a magnetic sensor provided with the formed magnetoresistive element, a sensor holder holding the magnetic sensor, and a slide member to which the sensor holder is fixed and movable along the magnetic scale.

  According to the present invention, since the positioning mark is attached to the substrate itself on which the magnetoresistive element is formed, the positioning accuracy of the positioning mark with respect to the magnetoresistive element is high. Accordingly, the magnetic sensor can be positioned with respect to a positioning reference that is visible in the same field of view as the positioning mark while visually recognizing the positioning mark. Therefore, the magnetic sensor can be accurately positioned with respect to the magnetic scale.

  In the present invention, the substrate is preferably a transparent substrate. In this way, the positioning mark can be surely visually recognized regardless of which surface of the substrate is provided with the positioning mark. Further, when the positioning reference is provided at a position overlapping with the transparent substrate, the positioning reference can be visually recognized through the transparent substrate. Therefore, the positioning mark can be easily aligned with the positioning reference.

  In the present invention, the magnetoresistive element is a magnetoresistive pattern formed of a thin film formed on the surface of the substrate, and the positioning mark is formed of a magnetic material in the same process as the process of forming the magnetoresistive pattern. It is desirable. Thus, when the magnetoresistive pattern and the positioning mark are formed in the same patterning process, the positional accuracy of both is high. Therefore, the magnetic sensor can be accurately positioned with respect to the magnetic scale.

  In the present invention, it is preferable that the positioning mark includes a first mark disposed on one edge of the substrate and a second mark disposed on the other edge. In this way, the magnetic sensor can be accurately positioned with respect to the magnetic scale without using a large positioning mark.

  In the present invention, it is preferable that the sensor holder includes a first through portion formed at a position overlapping the positioning mark. In this way, the positioning mark is not hidden by the sensor holder in a state where the sensor holder is disposed with the surface on which the magnetic sensor is disposed facing the magnetic scale. Therefore, the magnetic sensor can be positioned using the positioning mark.

  In the present invention, it is desirable that the slide member includes a second penetration part that overlaps the first penetration part of the sensor holder. In this way, the positioning mark is not hidden by the sensor holder and the slide member in a state where the slide member is arranged with the surface on which the sensor holder is arranged facing the magnetic scale. Therefore, the position of the magnetic sensor can be adjusted while visually recognizing the positioning mark through the first and second penetrating parts in a state where the sensor holder and the slide member are assembled to the magnetic scale.

  In the present invention, the sensor holder includes a plate-like portion to which the substrate is fixed, and a protruding portion that protrudes from the plate-like portion to the opposite side of the substrate, and the slide member includes the plate-like portion. The protrusion is disposed in the second penetrating portion that opens to the bottom surface of the recess, and the first penetrating portion includes an outer peripheral surface of the protruding portion and an inner periphery of the second penetrating portion. It is desirable to overlap the gap with the surface. By doing so, the magnetic sensor is roughly aligned by arranging the protruding portion in the second penetrating portion, and then, through the first penetrating portion from the gap between the inner peripheral surface of the second penetrating portion and the protruding portion. Precise position adjustment can be performed while visually recognizing the positioning marks.

  In the present invention, it is desirable that the protruding portion includes a cylindrical portion in which a part in the circumferential direction is cut out. If it does in this way, when pouring adhesive etc. in the crevice between the inner skin of the 2nd penetration part and a projection part, it will go to the outer circumference side of a projection part from the inner side of a cylindrical part via a notch part. Can be injected. Therefore, the fixing work of the sensor holder is easy.

Next, in order to solve the above-described problems, the manufacturing method of the position detecting device of the present invention includes a magnetic scale including tracks in which N poles and S poles are alternately arranged in a straight line, and a magnetoresistive element formed on the substrate. And a magnetic sensor, wherein the slide member is slidably assembled to the magnetic scale and is held by the sensor holder disposed in the holder fixing portion of the slide member. A first step of causing the magnetic sensor to face the track, a second step of adjusting a facing distance between the track and the magnetic sensor, and visually observing a positioning mark attached to the substrate using an optical system; A third step of adjusting the position of the sensor holder and a fourth step of fixing the sensor holder to the slide member are performed.

  According to the present invention, since the positioning mark is attached to the substrate itself on which the magnetoresistive element is formed, the positioning accuracy of the positioning mark with respect to the magnetoresistive element is high. Therefore, the magnetic sensor can be positioned with respect to the positioning reference visible in the visual field of the optical system while visually confirming the positioning mark with the optical system. Therefore, the magnetic sensor can be accurately positioned with respect to the magnetic scale.

  In the present invention, a gap that overlaps the positioning mark is provided between the holder fixing portion and the sensor holder, and in the fourth step, an adhesive is injected into the gap to slide the sensor holder into the slide. It is desirable to fix to the member. In this case, the gap between the holder fixing portion and the sensor holder is used to see the positioning mark, and when the position adjustment is completed, this gap can be used as a gap for injecting the fixing adhesive. Therefore, it is not necessary to provide a gap for injecting the fixing adhesive. Further, since the fixing adhesive can be injected from the side where the optical system for viewing the positioning marks is arranged, the fixing work of the sensor holder is easy.

  In the present invention, the gap is annular, and as the adhesive, a first adhesive that is injected into the gap first, and a second adhesive that is injected into the gap after the injection of the first adhesive. In the fourth step, it is preferable that the first adhesive is injected into a part of the gap in the circumferential direction, and then the second adhesive is injected into a part of the gap in the circumferential direction. Alternatively, in the fourth step, the second adhesive may be injected all around the gap. If it does in this way, adhesive strength can be secured.

  In the present invention, in the second step, it is desirable that the sensor holder is brought close to the magnetic scale to bring the magnetic sensor into contact with the track, and then the sensor holder is retracted from the magnetic scale. In this way, since the tilt of the substrate with respect to the track forming surface of the magnetic scale can be eliminated, the position of the magnetic sensor can be adjusted in two rotation directions with the two orthogonal directions parallel to the track forming surface as the rotation center line. Can do. Further, the position of the magnetic sensor can be adjusted in a direction perpendicular to the track forming surface.

  In the present invention, the extending direction of the track is a first direction, the direction perpendicular to the track forming surface of the magnetic scale is a second direction, and the first direction and the direction perpendicular to the second direction are the first direction. When three directions are set, in the third step, a first position adjustment for moving the sensor holder in the third direction, and a second position for rotating the sensor holder about a rotation center line extending in the second direction. It is desirable to make adjustments. In this way, the first position adjustment enables the position adjustment in the direction along the track forming surface and in the direction intersecting with the track extending direction (third direction). Further, the inclination of the magnetic sensor with respect to the track extending direction (first direction) can be eliminated by the second position adjustment.

  In the present invention, in the third step, the position of the sensor holder is adjusted by visually observing the positioning reference and the positioning mark attached to the optical member constituting the optical system within the visual field of the optical system. Is desirable. In this way, there is no need to separately perform an operation for setting the positioning reference. Therefore, the positioning of the magnetic sensor is easy.

According to the present invention, since the positioning mark is attached to the substrate itself on which the magnetoresistive element is formed, the positioning accuracy of the positioning mark with respect to the magnetoresistive element is high. Accordingly, the sensor can be positioned with respect to a positioning reference that is visible in the same field of view as the positioning mark while visually recognizing the positioning mark. Therefore, the magnetic sensor can be accurately positioned with respect to the magnetic scale.

It is a perspective view of the position detection apparatus of this invention. It is a perspective view of the state which assembled | attached the sensor holder and the magnetic sensor to the slide member. It is a disassembled perspective view of a slide member, a sensor holder, and a magnetic sensor. It is explanatory drawing of a sensor holder and a magnetic sensor. It is explanatory drawing of the 1st step and 2nd step of the manufacturing method of a position detection apparatus. It is explanatory drawing of the adjustment operation | work of the opposing distance of the magnetic sensor and track | truck performed at a 2nd step. It is explanatory drawing of the optical system used at the 3rd step of the manufacturing method of a position detection apparatus. It is explanatory drawing of the 3rd step of the manufacturing method of a position detection apparatus. It is explanatory drawing of the 4th step of the manufacturing method of a position detection apparatus.

  Embodiments of a position detection apparatus to which the present invention is applied will be described below with reference to the drawings.

(Configuration of position detection device)
FIG. 1 is a perspective view of a position detection apparatus to which the present invention is applied. The position detection device 1 is a magnetic linear encoder, and includes a magnetic scale 10, a slide member 20, a sensor holder 30, and a magnetic sensor 40 (see FIGS. 3 and 4). The magnetic scale 10 is a long member, and includes a track forming surface 12 provided with tracks 11 in which N poles and S poles are alternately arranged in a straight line at a predetermined pitch. The track 11 extends in the longitudinal direction of the magnetic scale 10. The three directions of XYZ shown in FIG. 1 are directions orthogonal to each other, the X direction is the extending direction of the track 11 (first direction), the Y direction is the direction perpendicular to the track forming surface 12 (second direction), The Z direction indicates a direction (third direction) orthogonal to the extending direction (first direction) of the track 11 in the track forming surface 12. In this specification, one side of the first direction X is the + X direction, the other side is the -X direction, one side of the second direction Y is the + Y direction, and the other side is the -Y direction. The third direction Z is a vertical direction, and one side (upward) of the third direction Z is defined as + Z direction and the other side (downward) is defined as −Z direction.

  As shown in FIG. 1, the magnetic scale 10 includes a track forming surface 12 facing the + Y direction and a guide surface 13 facing the + Z direction. The track 11 extends in the first direction X on the track forming surface 12, and the guide surface 13 extends in parallel with the track 11. The slide member 20 is a substantially rectangular parallelepiped member, and includes a first surface 20a facing the + Y direction, a second surface 20b facing the −Y direction, a third surface 20c facing the + Z direction, and a fourth surface facing the −Z direction. A surface 20d is provided. Two upper guide rollers 21 are attached to the corners located at both ends of the edge on the + Z direction side of the second surface 20b. The two upper guide rollers 21 can rotate around the rotation axis that faces the second direction Y. The slide member 20 is assembled to the magnetic scale 10 so that the two upper guide rollers 21 can travel on the guide surface 13. As a result, the slide member 20 can move relative to the magnetic scale 10 in the first direction X.

The slide member 20 is provided with two through portions 22 that open to the first surface 20a and the second surface 20b. One penetrating portion 22 is located at the + X direction end of the slide member 20, and the other penetrating portion 22 is located at the + X direction end of the slide member 20. A lateral guide roller 23 is attached to each of the two penetrating portions 22 so as to be rotatable around a rotation axis that faces the third direction Z. In addition, one lateral guide roller 23 that is rotatable around a rotation axis that faces the third direction Z is also attached to the center of the fourth surface 20d. These three lateral guide rollers 23 abut on the track forming surface 12 of the magnetic scale 10. Thereby, when the slide member 20 moves relative to the magnetic scale 10 in the first direction X, the distance between the slide member 20 and the track 11 can be kept constant.

  2 is a perspective view of a state in which the sensor holder 30 and the magnetic sensor 40 are assembled to the slide member 20, FIG. 2 (a) is a perspective view seen from the + Y direction side, and FIG. 2 (b) is a view from the −Y direction side. FIG. FIG. 3 is an exploded perspective view of the slide member 20, the sensor holder 30, and the magnetic sensor 40, and shows a state viewed from the −Y direction side. The three directions XYZ shown in FIGS. 2 and 3 indicate directions in a state where the slide member 20, the sensor holder 30, and the magnetic sensor 40 are assembled to the magnetic scale 10. 4 is an explanatory view of the sensor holder 30 and the magnetic sensor 40. FIG. 4 (a) is a front view seen from the -Y direction, FIG. 4 (b) is a side view seen from the -X direction, and FIG. (C) is the rear view seen from + Y direction.

  As shown in FIGS. 2 and 3, the slide member 20 has a holder fixing portion 24 for fixing the sensor holder 30. The holder fixing portion 24 is formed at a position closer to the −X direction side than the center in the first direction X of the slide member 20. The holder fixing portion 24 includes a groove-like concave portion 25 formed on the second surface 20 b and a circular second through portion 26 that opens at the center of the bottom surface of the concave portion 25. The recess 25 extends in the third direction Z in the range from the third surface 20c to the fourth surface 20d.

  The sensor holder 30 includes a substantially rectangular plate-shaped portion 31 disposed in the recess 25 of the holder fixing portion 24 and a protrusion 32 disposed in the second through portion 26 of the holder fixing portion 24. As shown in FIG. 3 and the like, the plate-like portion 31 includes a first surface 31a to which the substrate 41 of the magnetic sensor 40 is fixed, and a second surface 31b facing the opposite side to the first surface 31a. The first surface 31a faces the -Y direction, and a substantially rectangular recess 33 for arranging the magnetic sensor 40 is formed on the first surface 31a. As shown in FIG. 4B and the like, the protruding portion 32 includes a cylindrical portion 34 protruding from the second surface 31b of the plate-like portion 31 to the opposite side (+ Y direction) to the substrate 41, and an upper end surface of the cylindrical portion 34. Is further provided with a cylindrical cylindrical portion 35 protruding in the + Y direction. The cylindrical part 34 and the cylindrical part 35 have the same outer diameter. The cylindrical part 35 is formed with four notches 36 at equal angular pitches by notching a part in the circumferential direction.

  As shown by a broken line in FIG. 4C, the second penetrating portion 26 formed in the slide member 20 is slightly larger in diameter than the protruding portion 32 of the sensor holder 30. Specifically, the inner diameter of the second through portion 26 of the slide member 20 is larger than the outer diameter of the protruding portion 32 of the holder 30. For this reason, when the sensor holder 30 is arranged in the holder fixing portion 24, an annular gap D1 (FIG. 4 (c), FIG. 4) is formed between the inner peripheral surface of the second through portion 26 and the outer peripheral surface of the protruding portion 32. 5, FIG. 7 (b), FIG. 8, and FIG. 9) are formed. Therefore, it is possible to adjust the position of the sensor holder 30 in the third direction Z in a state where the sensor holder 30 is disposed on the holder fixing portion 24. In the sensor holder 30, the width dimension D <b> 2 (see FIG. 3) of the plate-like portion 31 in the first direction X is smaller than the inner width D <b> 3 (see FIG. 3) of the concave portion 25 in the first direction X. Accordingly, the sensor holder 30 is rotated around the rotation center line P1 (see FIGS. 2B and 4C) facing the second direction Y in a state where the sensor holder 30 is disposed on the holder fixing portion 24 and tilted. Adjustments can be made.

As shown in FIGS. 3 and 4, the plate-like portion 31 of the sensor holder 30 has first through portions 37 formed at two locations. As shown in FIG. 3, the 1st penetration part 37 is located in the recessed part 33 in the 1st surface 31a. Moreover, as shown in FIG.4 (c), the 1st penetration part 37 is located in the outer peripheral side of the protrusion part 32 in the 2nd surface 31b. The two first penetrating portions 37 have the same shape and are disposed on both sides of the protruding portion 32 in the first direction X. The two first penetrating portions 37 are located on a reference line L1 (see FIG. 4C) passing through the center of the protruding portion 32. Since the center of the protrusion 32 overlaps with the rotation center line P1 when performing the tilt adjustment (second position adjustment described later) of the sensor holder 30 described above, the reference line L1 intersects with the rotation center line P1. In a state where the sensor holder 30 is disposed in the holder fixing portion 24, the first through portion 37 of the sensor holder 30 overlaps with the circular second through portion 26 formed in the slide member 20 in the second direction Y. That is, the first penetrating portion 37 formed in the plate-like portion 31 of the sensor holder 30 is located on the inner peripheral side of the second penetrating portion 26 formed in the slide member 20. A gap D <b> 1 between the inner peripheral surface and the outer peripheral surface of the protruding portion 32 overlaps the first through portion 37.

  As shown in FIG. 2B, the sensor holder 30 has a shape that can hold the plate-like portion 31 with a jig 50 from both sides in the third direction Z. The jig 50 used in this embodiment includes three support bars 51 extending in parallel with the second direction Y. On the end face on the + Z direction side of the plate-like part 31, groove parts 38 in which the support bars 51 can be arranged are formed at two places on both ends in the first direction X. Further, on the end surface on the −Z direction side of the plate-like portion 31, a groove portion 38 in which the support rod 51 can be arranged is formed at one central position in the first direction X. These three groove portions 38 have an upper end edge of the plate-like portion 31 protruding from the concave portion 25 above the third surface 20c (+ Z direction) and the concave portion 25 in a state where the sensor holder 30 is disposed in the holder fixing portion 24. To the lower end edge of the plate-like portion 31 projecting downward (−Z direction) of the fourth surface 20d. Accordingly, with the sensor holder 30 disposed on the holder fixing portion 24, the two support bars 51 are brought into contact with the groove 38 from above (+ Z direction) and one support bar from below (−Z direction). 51 can be brought into contact with the groove 38. Thereby, the sensor holder 30 can be held by the jig 50.

  The support bar 51 that holds the sensor holder 30 does not interfere with the slide member 20 and the magnetic scale 10. Therefore, the sensor holder 30 can be moved relative to the slide member 20 and the magnetic scale 10 via the support bar 51. The jig 50 includes a mechanism (not shown) that translates the three support rods 51 in the third direction Z and the second direction Y. The jig 50 includes a mechanism (not shown) that rotates the three support rods 51 around a rotation center line P1 (see FIG. 2B) extending in the second direction Y. Position adjustment of the magnetic sensor 40 to be described later with respect to the magnetic scale 10 (third step of the manufacturing method of the position detection device 1) is performed using these mechanisms.

  As shown in FIGS. 3 and 4, the magnetic sensor 40 includes a rectangular substrate 41 and a magnetoresistive element 42 formed on the substrate 41. The magnetoresistive element 42 is a magnetoresistive pattern formed on the surface of the substrate 41 by a thin film forming process for forming a magnetic thin film and a patterning process such as photolithography. The substrate 41 is provided with positioning marks 43. In this embodiment, as the positioning mark 43, a mark made of a magnetic material formed on the substrate 41 in the same process as the process of forming the magnetoresistive element 42 (thin film forming process and patterning process) is used. For example, a mark obtained by patterning a magnetic thin film using the same mask as that used for forming the magnetoresistive pattern is used. The positioning mark 43 includes at least two marks, a first mark 43A and a second mark 43B. The first mark 43A is located on the outer edge of the substrate 41 in the + X direction, and the second mark 43B is located on the outer edge of the substrate 41 in the −X direction. The first mark 43 </ b> A and the second mark 43 </ b> B in this embodiment are both cross-shaped marks, and the center of the cross-shape is located on the reference line L <b> 1 passing through the center of the substrate 41. When the magnetic sensor 40 is held by the sensor holder 30, the reference line L <b> 1 passes through the rotation center line P <b> 1 of the sensor holder 30.

The substrate 41 of the magnetic sensor 40 is a transparent substrate, and is formed using a transparent material such as transparent resin or glass, for example. Therefore, the first mark 43A and the second mark 43B on the substrate 41 can be viewed from either one side (+ Y direction side) or the other side (−Y direction side) of the second direction Y. Visible. The first mark 43 </ b> A and the second mark 43 </ b> B overlap with the first through portion 37 that opens in the recess 33 when the magnetic sensor 40 is disposed in the recess 33 of the sensor holder 30. Therefore, as shown in FIG. 4C, when the sensor holder 30 that holds the magnetic sensor 40 is viewed from the second surface 31 b side, it is formed on the substrate 41 of the magnetic sensor 40 through the first through portion 37. The first mark 43A and the second mark 43B can be visually recognized. Further, as described above, the first through portion 37 overlaps the second through portion 26 of the holder fixing portion 24 in the second direction Y when the sensor holder 30 is disposed in the holder fixing portion 24 of the slide member 20. Therefore, as will be described later, when the sensor holder 30 that holds the magnetic sensor 40 is disposed on the holder fixing portion 24 of the slide member 20 when viewed from the first surface 20a side of the slide member 20, the first through portion The first mark 43A and the second mark 43B formed on the substrate 41 of the magnetic sensor 40 can be visually recognized through 37 and the second through portion 26 (see FIG. 7B).

(Method for manufacturing position detecting device)
A method for manufacturing the position detection apparatus 1 of the present embodiment will be described with reference to FIGS. In the manufacturing method of the position detection apparatus 1 of the present embodiment, the first to fourth steps described below are performed. In the first to fourth steps, the slide member 20 is assembled to the magnetic scale 10, and the magnetic sensor 40 mounted on the slide member 20 is positioned and fixed with respect to the magnetic scale 10. The magnetic sensor 40 is positioned by using the jig 50 and the optical system 60 (see FIG. 7A). Prior to the first step, the magnetic scale 10, the slide member 20, the sensor holder 30, and the magnetic sensor 40 are prepared, and the magnetic sensor 40 is assembled to the sensor holder 30 as shown in FIG.

  FIG. 5A is an explanatory diagram illustrating a first step of the method for manufacturing the position detection device 1, and FIG. 5B is an explanatory diagram illustrating a second step. FIG. 6 is an explanatory view of the adjustment operation of the facing distance between the magnetic sensor 40 and the track 11 performed in the second step. FIG. 6A shows the track 11 of the magnetic scale 10 and the magnetic sensor 40 in contact with each other. FIG. 6B shows a state where a predetermined gap is formed between the track 11 and the magnetic sensor 40. In addition, illustration of the slide member 20 is abbreviate | omitted in FIG. 6 (a), (b).

  In the first step, as shown in FIG. 2, the sensor holder 30 that holds the magnetic sensor 40 is disposed on the holder fixing portion 24 of the slide member 20. Then, as shown in FIG. 5A, the slide member 20 is assembled to the magnetic scale 10 so as to be relatively movable in the first direction X. Specifically, the two upper guide rollers 21 are placed on the guide surface 13 of the magnetic scale 10, and the three lateral guide rollers 23 are brought into contact with the track forming surface 12 of the magnetic scale 10. Thereby, the sensor holder 30 arranged in the holder fixing part 24 faces the track forming surface 12 of the magnetic scale 10. Since the magnetic sensor 40 is attached to the first surface 31 a of the sensor holder 30 facing the track forming surface 12, the magnetic sensor 40 faces the track forming surface 12. As a result, the magnetoresistive element 42 provided in the magnetic sensor 40 faces the track 11 formed on the track forming surface 12.

  In the second step, the sensor holder 30 is held by the jig 50 as shown in FIG. As a result, the sensor holder 30 can be moved in the second direction Y using the jig 50. In the second step, a portion (not shown) of the jig 50 is operated to move the three support rods 51 holding the sensor holder 30 in the −Y direction. As a result, the magnetic sensor 40 approaches the track 11 of the magnetic scale 10. As shown in FIG. 6A, the magnetic sensor 40 (substrate 41) is brought into contact with the track 11 (track forming surface 12) of the magnetic scale 10, and then the moving direction of the sensor holder 30 is switched to the + Y direction. As a result, the magnetic sensor 40 moves backward from the track 11. The amount of movement of the sensor holder 30 in the + Y direction is controlled, and the position of the sensor holder 30 is adjusted so that the facing distance D4 between the track 11 and the magnetic sensor 40 becomes a predetermined appropriate value.

FIG. 7 is an explanatory diagram of the optical system 60 used in the third step of the manufacturing method of the position detection device 1, and FIG. 7A is a side view schematically showing the position detection device 1 and the optical system 60. (B) is an explanatory view showing the field of view of the optical system 60. The third step is performed with the position detection device 1 and the optical system 60 installed so that the second penetrating portion 26 of the slide member 20 assembled to the magnetic scale 10 enters the field of view 61 of the optical system 60 (FIG. 7 (b)). In the visual field 61 of the optical system 60, a positioning reference 63 attached to the optical member 62 (see FIG. 7A) constituting the optical system 60 is displayed. The positioning reference 63 of this embodiment is a straight line that intersects the optical axis 64 of the optical system 60 and extends in the first direction X. The positioning reference 63 is, for example, a linear mark formed by performing hairline processing on the optical member 62 such as a lens. In this embodiment, as shown in FIG. 7A, the optical system 60 is installed to face the track forming surface 12 of the magnetic scale 10. Then, as shown in FIG. 7B, the position detection device is arranged so that the optical axis 64 of the optical system 60 coincides with the center of the second penetrating portion 26 and the track 11 and the positioning reference 63 are parallel. The positional relationship between 1 and the optical system 60 is determined.

  FIG. 8 is an explanatory diagram of a third step of the manufacturing method of the position detection device 1, FIG. 8A is an explanatory diagram of the first position adjustment, FIG. 8B is an explanatory diagram of the second position adjustment, FIG. (C) is a figure which shows the state which 2nd position adjustment was completed. As shown in FIGS. 8A to 8C, the second penetrating portion 26 of the slide member 20 is visible in the visual field 61 of the optical system 60, and the sensor holder 30 is in the second penetrating portion 26. The protrusion 32 and the two first through portions 37 provided on the outer periphery thereof are visible. In the two first through portions 37, the first mark 43A and the second mark 43B are visible, respectively. In the third step, the sensor holder 30 is positioned so that the positioning mark 43 (first mark 43A and second mark 43B) visible in the field of view 61 of the optical system 60 and the positioning reference 63 have a predetermined positional relationship. Adjust the position. Specifically, the position of the sensor holder 30 is adjusted by the jig 50 so that the first mark 43A and the second mark 43B overlap the positioning reference 63.

  As shown in FIG. 8A, the arrangement direction (reference line L1) of the first mark 43A and the second mark 43B is inclined with respect to the positioning reference 63, and the first mark 43A and the second mark 43B are aligned. When the intermediate point (rotation center line P1) is shifted in the third direction Z with respect to the positioning reference 63, in the third step, first, the sensor holder 30 is moved in the third direction Z using the jig 50. 1 position adjustment is performed. An arrow A1 shown in FIG. 8A indicates the moving direction of the sensor holder 30 by the first position adjustment. In the example of FIG. 8A, the sensor holder 30 is moved in the + Z direction until the intermediate point (rotation center line P1) between the first mark 43A and the second mark 43B overlaps the positioning reference 63 (see FIG. 8B). ).

  In the third step, subsequently, a second position adjustment for rotating the sensor holder 30 around the rotation center line P1 using the jig 50 is performed. An arrow A2 shown in FIG. 8B indicates the rotation direction of the sensor holder 30 by the second position adjustment. By the second position adjustment, the inclination of the sensor holder 30 around the rotation center line P1 is adjusted, and the cross-shaped centers of the first mark 43A and the second mark 43B are superimposed on the positioning reference 63. Thereby, as shown in FIG. 8C, the second position adjustment is completed, and the alignment of the first mark 43A and the second mark 43B with respect to the positioning reference 63 is completed. As described above, the positioning reference 63 is accurately positioned in advance with respect to the track 11 of the magnetic scale 10. Therefore, in the third step, the position adjustment between the magnetic sensor 40 fixed to the sensor holder 30 and the track 11 on the magnetic scale 10 is completed.

FIG. 9 is an explanatory diagram of the fourth step of the method for manufacturing the position detecting device 1, FIG. 9 (a) is an explanatory diagram of temporary fixing, and FIG. 9 (b) is an explanatory diagram of permanent fixing. In the fourth step, the sensor holder 30 is fixed to the slide member 20 with an adhesive. As the adhesive, a first adhesive 70 and a second adhesive 71 are used. The first adhesive 70 and the second adhesive 71 may be the same component or different. For example, as shown in FIG. 9A, the first adhesive 70 is first injected into the gap D1 between the inner peripheral surface of the second penetrating portion 26 and the outer peripheral surface of the protruding portion 32 to perform temporary fixing. After that, as shown in FIG. 9B, the second adhesive 71 is further injected from above the first adhesive 70, and the sensor holder 30 is permanently fixed to the slide member 20. The gap D1 is annular, and the position where the first adhesive 70 is injected is a part of the circumferential direction of the gap D1. Since the position where the first adhesive 70 is injected is a position that does not overlap the first mark 43A and the second mark 43B, temporary fixing can be performed while confirming the positioning state of the sensor holder 30. As the 1st adhesive agent 70, what hardens | cures in a short time is used. The range in which the second adhesive 71 is injected is desirably the entire circumference of the gap D1, but may be a part of the circumferential direction of the gap D. In this embodiment, a cylindrical portion 35 is provided at the tip of the protruding portion 32, and a notch portion 36 is formed here. Therefore, in the fourth step, the first adhesive 70 is inserted into the gap D1 between the inner peripheral surface of the second through portion 26 and the outer peripheral surface of the protruding portion 32 from the inside of the cylindrical portion 35 via the notch portion 36. And the second adhesive 71 can be injected. By fixing the first adhesive 70 and the second adhesive 71, the fixing of the sensor holder 30 to the slide member 20 is completed. Therefore, the magnetic sensor 40 is fixed to the slide member 20 via the sensor holder 30.

(Function and effect)
As described above, in the position detection device 1 of this embodiment, the positioning mark 43 is attached to the substrate 41 itself on which the magnetoresistive element 42 is formed. At the time of manufacturing the position detecting device 1, the positioning mark 43 is positioned with respect to the positioning reference 63 visible in the field of view 61 of the optical system 60 while visually observing the positioning mark 43 using the optical system 60. The magnetic sensor 40 is positioned with respect to the scale 10. Thus, when the magnetoresistive element 42 and the positioning mark 43 are provided on the same substrate 41, the positional accuracy of the positioning mark 43 with respect to the magnetoresistive element 42 can be improved. Therefore, the magnetic sensor 40 can be accurately positioned with respect to the magnetic scale 10 by using the positioning mark 43. Thereby, since the track 11 of the magnetic scale 10 and the magnetoresistive element 42 of the magnetic sensor 40 can be aligned in a good positional relationship, the position detection device 1 with good position detection accuracy can be obtained.

  In the manufacturing method of the position detection device 1 according to the present embodiment, as described above, the optical system 60 and the magnetic scale 10 are used to perform the position adjustment operation while visually observing the positioning mark 43 and the positioning reference 63 within the optical field of view. Is set and set in advance accurately. As described above, by using the optical system 60 installed in advance, it is possible to perform the position adjusting operation and the fixing operation of the magnetic sensor 40 under a fixed optical field of view. Therefore, the position adjustment work and fixing work of the magnetic sensor 40 are easy. Further, even during the fixing operation, the operation can be performed while visually recognizing the alignment state of the magnetic sensor 40 and the magnetic scale 10 (the positional relationship between the positioning reference 63 and the positioning mark 43). Therefore, the positional deviation of the magnetic sensor 40 can be easily found.

  In this embodiment, since the position of the magnetic sensor 40 is adjusted while observing the positioning mark 43 in the optical field of view, the position can be adjusted with high precision while using simple equipment. Further, it is possible to perform image processing by photographing the inside of the optical field of view, and it is also possible to automatically adjust the position of the magnetic sensor 40 based on the result of the image processing.

  In this embodiment, the magnetoresistive pattern that is the magnetoresistive element 42 and the positioning mark 43 are formed in the same process (a thin film forming process and a patterning process), for example, using a photolithography technique. Therefore, both positional accuracy is high. Therefore, the magnetic sensor 40 can be accurately positioned with respect to the magnetic scale 10 by using the positioning marks 43.

In this embodiment, since the substrate 41 is a transparent substrate, the positioning mark 43 can be reliably visually recognized regardless of which surface of the substrate 41 is attached. For example, in this embodiment, since the positioning reference 63 provided on the surface facing the track 11 can be viewed from the opposite side (+ Y direction side) of the track 11, the positioning mark is placed with the magnetic sensor 40 facing the track 11. 43 can be used to position the magnetic sensor 40. Further, when the positioning reference 63 is provided at a position overlapping the substrate 41, the positioning reference 63 can be visually recognized through the transparent substrate. For example, the track 11 itself can be used as a positioning reference. In this case, the state in which the track 11 and the positioning mark 43 overlap can be visually recognized through the transparent substrate. Therefore, positioning of the magnetic sensor 40 is easy.

  In this embodiment, two marks of the first mark 43A and the second mark 43B are used as the positioning marks 43, and these marks are arranged at two locations on the reference line L1 at the outer edge of the substrate 41. Therefore, the tilt adjustment of the magnetic sensor 40 with respect to the positioning reference 63 can be performed precisely. In addition, since precise positioning can be performed without using a large positioning mark, it is not necessary to secure a space for attaching the large positioning mark on the substrate 41.

  In this embodiment, the sensor holder 30 is provided with a first through part 37 that overlaps with the positioning mark 43, and the slide member 20 is provided with a second through part 26 that overlaps with the positioning mark 43 and the first through part 37. Therefore, the positioning mark 43 on the magnetic sensor 40 is not hidden by the sensor holder 30 and the slide member 20 in a state where the slide member 20 is arranged with the surface on which the sensor holder 30 is arranged facing the magnetic scale 10. Therefore, while the sensor holder 30 holding the magnetic sensor 40 and the slide member 20 are assembled to the magnetic scale 10, while visually confirming the positioning mark 43 through the first through portion 37 and the second through portion 26, The position of the magnetic sensor 40 can be adjusted.

  In this embodiment, the positioning of the sensor holder 30 that holds the magnetic sensor 40 can be performed by arranging the protruding portion 32 of the sensor holder 30 in the second through portion 26 of the slide member 20. Then, it is possible to perform precise position adjustment while visually recognizing the positioning mark 43 through the first through portion 37 from the gap D1 between the inner peripheral surface of the second through portion 26 and the outer peripheral surface of the protruding portion 32.

  In this embodiment, the gap D1 between the inner peripheral surface of the second penetrating portion 26 and the outer peripheral surface of the protruding portion 32 is annular, and this gap D1 is fixed to the fixing adhesive (after the position adjustment of the sensor holder 30 is completed) The first adhesive 70 and the second adhesive 71) are used as gaps for injection. Therefore, it is not necessary to provide a gap for injecting the fixing adhesive. In addition, since the fixing adhesive can be injected from the side where the positioning mark 43 is viewed, after the position adjustment of the sensor holder 30 is completed, the fixing adhesive from the side where the optical system 60 is disposed. Can be injected. Therefore, it is easy to fix the sensor holder 30 to the slide member 20. In this embodiment, the first adhesive 70 and the second adhesive 71 are used for fixing in two stages, and the first adhesive 70 is used for a short time while confirming the positioning state of the sensor holder 30. Can be temporarily fixed. Thereafter, the second adhesive 71 is injected into the entire circumference of the gap D1 or a part in the circumferential direction to perform the main fixing, so that the adhesive strength can be ensured.

  In this embodiment, in the second step of the manufacturing method of the position detection device 1, the sensor holder 30 holding the magnetic sensor 40 is brought close to the magnetic scale 10 to bring the substrate 41 into contact with the track 11. The distance between the magnetic sensor 40 and the track 11 is adjusted by retracting from the magnetic scale 10. In this way, since the inclination of the substrate 41 with respect to the track forming surface 12 can be eliminated, two rotations with the two orthogonal directions (the first direction X and the third direction Z) parallel to the track forming surface 12 as the rotation center line are performed. The position of the magnetic sensor 40 can be adjusted in the direction. Further, the position of the magnetic sensor 40 can be adjusted in a direction perpendicular to the track forming surface 12 (second direction Y). That is, the position adjustment with three degrees of freedom can be performed in the second step.

  In this embodiment, in the third step of the manufacturing method of the position detection device 1, the first position adjustment for moving the sensor holder 30 in the third direction Z while visually confirming the positioning mark 43 with the optical system 60, and the sensor holder 30. Is adjusted around the rotation center line P1 extending in the second direction Y. That is, in the third step, the position adjustment with two degrees of freedom can be completed. As described above, in the present embodiment, the position adjustment with 5 degrees of freedom is completed in the second step and the third step for the magnetic sensor 40 that can move in a total of 6 degrees of freedom in the XYZ three-axis directions and the rotation directions of the respective axes. Can do. The remaining one-degree-of-freedom moving direction is the extending direction of the track 11 (first direction X). Since the positional deviation in this direction corresponds to the deviation of the origin position, it is possible to omit precise positional adjustment when the position detecting device 1 is manufactured.

(Modification)
(1) The positioning mark 43 in the above form is a cross-shaped mark, but may be a mark of another shape such as a dot-shaped mark or an arrow-shaped mark. Further, the positioning mark 43 includes two marks (first mark 43A and second mark 43B) arranged in the first direction X with the rotation center line P1 interposed therebetween, but may be formed at other positions. . Also, one mark may be used instead of two marks. For example, a single linear mark extending in the first direction X may be used. Alternatively, three or more marks may be provided.

  (2) In the fourth step of the above embodiment, the two-stage fixing operation is performed using the first adhesive 70 and the second adhesive 71, but the fixing operation using the first adhesive 70 is omitted, and the second step The sensor holder 30 may be fixed to the slide member 20 using only the adhesive 71. Further, the injection region of the second adhesive 71 may not be the entire circumference of the gap D1. For example, the second adhesive 71 does not have to be injected into a position overlapping the first mark 43A and the second mark 43B. Moreover, you may inject | pour into the position where the 1st adhesive agent 70 and the 2nd adhesive agent 71 do not mutually overlap.

DESCRIPTION OF SYMBOLS 1 ... Position detection apparatus 10 ... Magnetic scale 11 ... Track 12 ... Track formation surface 13 ... Guide surface 20 ... Slide member 20a ... First surface 20b ... Second surface 20c ... Third surface 20d ... Fourth surface 21 ... Upper guide roller 22 ... penetrating portion 23 ... lateral guide roller 24 ... holder fixing portion 25 ... concave portion 26 ... second penetrating portion 30 ... sensor holder 31 ... plate-like portion 31a ... first surface 31b ... second surface 32 ... projecting portion 33 ... concave portion 34 ... Cylindrical part 35 ... Cylindrical part 36 ... Notch part 37 ... First through part 38 ... Groove part 40 ... Magnetic sensor 41 ... Substrate 42 ... Magnetic resistance element 43 ... Marking mark 43A ... First mark 43B ... Second mark 50 ... Jig 51 ... Support rod 60 ... Optical system 61 ... Field of view 62 ... Optical member 63 ... Positioning reference 64 ... Optical axis 70 ... First adhesive 71 ... Second adhesive D1 ... Gap D2 ... Width dimension D3 ... Internal width D4 ... Opposite Septum L1 ... reference line P1 ... rotational center line X ... first direction Y ... second direction Z ... third direction

Claims (15)

A magnetic scale having tracks in which N poles and S poles are alternately arranged in a straight line;
A substrate provided with a positioning mark, and a magnetic sensor comprising a magnetoresistive element formed on the substrate;
A sensor holder for holding the magnetic sensor;
A position detection device comprising: a slide member to which the sensor holder is fixed and movable along the magnetic scale.   The position detection device according to claim 1, wherein the substrate is a transparent substrate. The magnetoresistive element is a magnetoresistive pattern formed on the surface of the substrate,
The position detecting device according to claim 1, wherein the positioning mark is formed of a magnetic material in the same process as the process of forming the magnetoresistive pattern.   4. The positioning mark according to claim 1, wherein the positioning mark includes at least a first mark disposed on an edge on one side of the substrate and a second mark disposed on an edge on the other side. 5. The position detection device according to item.   5. The position detection device according to claim 1, wherein the sensor holder includes a first penetrating portion formed at a position overlapping with the positioning mark. 6.   The position detecting device according to claim 5, wherein the slide member includes a second penetrating portion that overlaps the first penetrating portion of the sensor holder. The sensor holder includes a plate-like portion to which the substrate is fixed, and a protruding portion that protrudes from the plate-like portion to the opposite side of the substrate,
The slide member includes a concave portion in which the plate-like portion is disposed, and the protruding portion is disposed in the second through portion that opens to a bottom surface of the concave portion,
The position detection device according to claim 6, wherein the first through portion overlaps a gap between an outer peripheral surface of the protruding portion and an inner peripheral surface of the second through portion.   The position detecting device according to claim 7, wherein the protruding portion includes a cylindrical portion in which a part in the circumferential direction is cut out. A method of manufacturing a position detecting device comprising: a magnetic scale having tracks in which N poles and S poles are alternately arranged in a straight line; and a magnetic sensor having a magnetoresistive element formed on a substrate,
A first step in which a slide member is slidably assembled to the magnetic scale, and the magnetic sensor held by a sensor holder disposed in a holder fixing portion of the slide member is opposed to the track;
A second step of adjusting a facing distance between the track and the magnetic sensor;
A third step of visually adjusting a positioning mark attached to the substrate using an optical system and adjusting the position of the sensor holder;
And a fourth step of fixing the sensor holder to the slide member. A gap that overlaps the positioning mark is provided between the holder fixing portion and the sensor holder,
The method according to claim 9, wherein in the fourth step, an adhesive is injected into the gap to fix the sensor holder to the slide member. The gap is annular;
As the adhesive, comprising a first adhesive that is injected into the gap first, and a second adhesive that is injected into the gap after the injection of the first adhesive,
In the fourth step, the first adhesive is injected into a part of the gap in the circumferential direction, and then the second adhesive is injected into a part of the gap in the circumferential direction. Item 11. A method for manufacturing the position detection device according to Item 10.   12. The method of manufacturing a position detecting device according to claim 11, wherein in the fourth step, the second adhesive is injected all around the gap.   13. In the second step, the sensor holder is brought close to the magnetic scale, the magnetic sensor is brought into contact with the track, and then the sensor holder is retracted from the magnetic scale. A method for manufacturing the position detection device according to any one of the above. The direction in which the track extends is the first direction, the direction perpendicular to the track forming surface of the magnetic scale is the second direction, and the direction perpendicular to the first direction and the second direction is the third direction. When
In the third step,
A first position adjustment for moving the sensor holder in the third direction;
The method for manufacturing a position detection device according to claim 9, wherein the second position adjustment is performed by rotating the sensor holder about a rotation center line extending in the second direction. . In the third step,
15. The position of the sensor holder is adjusted by visually observing a positioning reference and a positioning mark attached to an optical member constituting the optical system in a visual field of the optical system. A method for manufacturing the position detection device according to any one of the items.

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