WO2008053926A1

WO2008053926A1 - Motion sensor

Info

Publication number: WO2008053926A1
Application number: PCT/JP2007/071241
Authority: WO
Inventors: Koji Kurata; Ichiro Tokunaga; Masao Kasashima
Original assignee: Alps Electric Co., Ltd.
Priority date: 2006-11-02
Filing date: 2007-10-31
Publication date: 2008-05-08
Also published as: JP2010019552A

Abstract

[PROBLEMS] A contactless motion sensor using a magnetoresistive effect element and especially a motion sensor having an improved linearity of position detection. [MEANS FOR SOLVING PROBLEMS] A first magnet (4) and a second magnet (5) are crossed, and a magnetoresistive effect element (GMR element) (15) is linearly moved in the space between the magnets (4, 5). Between the magnets (4, 5), a rotating magnetic field region where an external magnetic field is rotation-displaced is formed from the left-side ends (4b, 5b) and right-side ends (4c, 5c). The magnetoresistive effect element (15) is supported movably within the rotating magnetic field region. Therefore, while the magnetoresistive effect element (15) is moving, the direction of magnetization in the free magnetic layer of the magnetoresistive effect element (15) gradually varies. Consequently, the linearity of the position detection is improved.

Description

Specification

Technical field of movement sensor

The present invention relates to a non-contact type movement sensor using a magnetoresistive effect element, and more particularly to a movement sensor that can improve the linearity of position detection.

Background art

[0002] MR elements using the magnetoresistive effect are used in a mobile sensor described in Patent Document 1 below. The MR element can detect the change in the direction of the external magnetic field with high accuracy based on the change in electrical resistance that accompanies the change in direction. Higher performance and longer life can be expected compared to an element that reads changes in the magnetic field strength of an external magnetic field.

[0003] In the invention described in Patent Document 1, for example, as shown in FIG. 5 and FIG. 7 of Patent Document 1, the permanent magnet and the magnetic detection element are arranged to face each other, and the permanent magnet is supported to move in the linear direction. Has been.

In such an arrangement, when the magnetic detection element is arranged near the magnetic pole of the permanent magnet, the magnetic detection element is opposed to the permanent magnet of the magnetic detection element from the permanent magnet. When an external magnetic field in a direction perpendicular to the surface penetrates and the magnetic detection element is between the magnetic poles as shown in FIG. 7 of Patent Document 1, the magnetic field is parallel to the opposite surface of the magnetic detection element. An external magnetic field enters.

Thus, in Patent Document 1, since the direction of the external magnetic field that enters the magnetic detection element changes by moving the permanent magnet, the magnetic detection element uses an MR element that uses the magnetoresistive effect. If so, the electric resistance value of the magnetic sensing element changes due to the change in direction of the external magnetic field.

Patent Document 1: JP-A-5-280916

Disclosure of the invention

Problems to be solved by the invention

However, in the invention described in Patent Document 1, the opposite of the magnetic detection element It is considered that the external magnetic field area that penetrates in the direction parallel to the surface is too long, and the linearity of position detection cannot be improved appropriately.

As shown in FIG. 5 of Patent Document 1, etc., in the invention described in Patent Document 1, the permanent magnet has a rod shape, and the relative movement direction of the magnetic detection element and the width direction of the permanent magnet are It coincides with the direction of the center line passing through the center. For this reason, in the region between the magnetic poles of the permanent magnet shown in FIG. 7 of Patent Document 1, the vector component of the external magnetic field from almost one direction dominates into the magnetic detection element, and the magnetic field in the region between the magnetic poles is dominant. It is considered that the change in electrical resistance of the detection element (MR element) becomes small (or no change in electrical resistance), and therefore the linearity (linearity) of position detection cannot be improved appropriately.

[0008] Therefore, the present invention is to solve the above-described conventional problems, and relates to a non-contact type movement sensor using a magnetoresistive effect element, and in particular, to improve the linearity (linearity) of position detection. The purpose is to provide a movement sensor that can!

Means for solving the problem

[0009] The movement sensor according to the present invention includes a magnetoresistive element having a laminated structure using a magnetoresistive effect in which an electric resistance changes with a change in direction of an external magnetic field, and a magnet for generating the external magnetic field. Have

One of the magnetoresistive effect element and the magnet is movably supported, and the magnetoresistive effect element and the magnet are spaced apart in a height direction, and when viewed from directly above the height direction, A center line passing through the center of the width dimension of the magnet and the relative movement path of the magnetoresistive element intersect in the middle, and from the intersection to the starting point of relative movement of the magnetoresistive element and the end point of relative movement. The center line and the magnetoresistive effect element are arranged so as to face each other so that the distance between the relative movement paths of the magnetoresistive effect element gradually increases in the width direction.

With the relative movement of the magnetoresistive effect element, the penetration direction of the external magnetic field from a plane direction parallel to the laminated interface entering the laminated structure is rotationally displaced, and the electric resistance value of the magnetoresistive effect element The moving position is detected by changing.

In the present invention, with the above-described configuration, the position detection linearity (linearity) can be improved in a non-contact type movement sensor using a magnetoresistive effect element as compared with the conventional case. That is, in the present invention, as described above, the center line of the magnet and the relative movement path of the magnetoresistive element intersect each other along the way, and the starting point of the relative movement of the magnetoresistive element from the intersection , And the magnetoresistive element and the magnet are opposed to each other so that the distance between the center line and the relative movement path of the magnetoresistive element gradually increases in the width direction toward the end point of the relative movement! The

[0012] As in the prior art, when the center line of the magnet and the relative movement path of the magnetoresistive element are aligned, the direction of the external magnetic field that enters the magnetoresistive element near the center of the magnet As a result, the linearity of position detection could not be improved.

On the other hand, in the present invention, since the center line of the magnet and the relative movement path of the magnetoresistive effect element do not coincide with each other, but intersect with each other from an oblique direction, if the magnetoresistive effect element is relatively moved, The magnetoresistive effect element is always in a position that is moved with respect to the center line of the magnet, and accordingly, with the relative movement of the magnetoresistive effect element, the magnetoresistive effect element is parallel to the laminated interface of the magnetoresistive effect element. The direction of penetration of the external magnetic field from the surface direction can be gradually rotationally displaced.

[0014] Therefore, the linearity (linearity) of position detection can be improved as compared with the conventional case.

[0015] In the present invention, the magnet has a center line length passing through the center in the width direction longer than a dimension in the width direction, and both side surfaces located on both sides of the center line are the center line. It is formed in a shape extending in a parallel direction so that the invasion direction of the external magnetic field from the plane direction parallel to the laminated interface of the magnetoresistive effect element is appropriately adjusted with the relative movement of the magnetoresistive effect element. It can be rotated and displaced, which is preferable.

[0016] The magnetoresistive element can be used as a linear movement sensor when it is relatively moved linearly.

In the present invention, when the magnetoresistive effect element is supported so as to be movable and the magnet is fixedly arranged, it is possible to realize downsizing with a simple configuration.

[0018] In the present invention, the magnetoresistive effect element has a laminated interface of the laminated structure oriented in a direction perpendicular to a surface of the magnet facing the magnetoresistive effect element. It is preferable that the facing surface is a single magnetic pole surface. With such a configuration, the relative movement of the magnetoresistive element from the starting point of the relative movement of the magnetoresistive element to the intersection and the end point is parallel to the stacked interface of the magnetoresistive element. It is possible to rotate and displace the penetration direction of the external magnetic field from the proper plane direction more appropriately.

In the present invention, the first magnetic member and the second magnetic member are opposed to each other with a gap in the height direction, and the first magnetic member and the second magnetic member are A first center line passing through the center of the width dimension of the first magnetic member and a second center line passing through the center of the width dimension of the second magnetic member when viewed from directly above the vertical direction. And the first center line and the second center line are formed so as to be separated from each other in the width direction from the intersection to the one end direction and from the intersection to the other end direction. And at least one of the first magnetic member and the second magnetic member is formed of the magnet,

In the space between the first magnetic member and the second magnetic member, the directional force of the external magnetic field generated from the facing surface of one magnetic member toward the facing surface of the other magnetic member. A rotating magnetic field region that gradually rotates is formed from one end side to the other end side of the magnetic member and the second magnetic member, and the magnetoresistive effect element has a laminated interface force of the laminated structure and the magnetic force. The member is directed in a direction orthogonal to the surface of the member facing the magnetoresistive effect element, and is relatively moved so as to pass through the rotating magnetic field region from the one end side toward the other end side. preferable.

[0020] In the configuration described above, two magnetic members are opposed to each other in the height direction, and the force and crossing from the oblique direction when the center line of each magnetic member is viewed from directly above the height direction. Therefore, it is possible to easily and appropriately form a rotating magnetic field region in which an external magnetic field gradually rotates and displaces from the one end side to the other end side between the magnetic members.

[0021] Then, by restricting the magnetoresistive effect element to move relatively between the magnetic members and within the rotating magnetic field region, the magnetoresistive effect is increased with the relative movement of the magnetoresistive effect element. The electric resistance value of the element can be continuously changed, and the linearity (direct spring) of position detection can be improved more effectively.

In the present invention, the opposing surfaces of the first magnetic member and the second magnetic member are band-shaped. The magnetoresistive element intersects the first magnetic member when viewed from directly above the height direction. The force of moving the center in the width direction between the first center line and the second center line of the second magnetic member in a straight line more effectively improves the linearity of the position detection. It can also be used as a linear movement sensor.

In the present invention, the first magnetic member and the second magnetic member are both formed of magnets, and the facing surface of the first magnetic member and the facing surface of the second magnetic member are different. It is possible to form a rotating magnetic field region that is appropriately rotated and displaced with little disturbance of the external magnetic field between the magnetic members, and that the linearity (linearity) of position detection can be improved. Is possible.

The invention's effect

[0024] According to the movement sensor of the present invention, the linearity (linearity) of position detection can be improved as compared with the conventional case.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a partial perspective view for showing the internal structure of the movement sensor in the present embodiment, and FIG. 2 is a movement direction of the magnetoresistive effect element constituting the movement sensor shown in FIG. 1, and a magnet and a magnetoresistance effect. 3 (a) to 3 (e) are partial plan views for showing the positional relationship with the element. When the magnetoresistive effect element moves from position A to E shown in FIG. Fig. 4 is a partial cross-sectional view of the resistive element and magnet cut in the height direction and viewed from the direction of the arrow. Fig. 4 is a cross-sectional view of the laminated structure of the magneto-resistance element in the film thickness direction. FIG. 4 is an enlarged cross-sectional view of FIG.

As shown in FIG. 1, the movement sensor 1 in the present embodiment includes a housing 2, a magnetic detection unit 3 including a magnetoresistive element provided in the housing 2, a first magnet 4, and And a second magnet 5.

[0027] Here, in each figure, the illustrated X direction is the width direction, the illustrated Y direction is the length direction, and the illustrated Z direction is the height direction. Each direction is orthogonal to the other two directions. The height direction indicates a direction in which the magnet and the magnetoresistive effect element face each other with a predetermined interval.

[0028] As shown in FIG. 1, the side surface 2a of the housing 2 has a linear opening along the Y direction in the figure. Part 6 is formed. As shown in FIG. 1, the magnetic detection unit 3 is provided on the substrate 7, and the lever 8 connected to the substrate 7 is exposed to the outside through the opening 6.

[0029] The substrate 7 is supported by two rail portions 9 and 10 extending in parallel in the length direction (Y direction in the figure) with a predetermined interval in the width direction (X direction in the figure), and the lever By moving 8 in the Y direction in the figure, the substrate 7 moves in the Y direction in the figure along the rail portions 9 and 10. As a result, the magnetic detection unit 3 can be moved along the Y direction in the figure.

The magnetic detection unit 3 includes at least one magnetoresistive element 15. The magnetic detection unit 3 is also provided with a fixed resistance element (not shown), and a series circuit is configured via the magnetoresistance effect element 15 and an output extraction unit. Alternatively, the magnetoresistive effect element 15 and the fixed resistance element constitute a bridge circuit. Although not shown, a detection circuit for detecting the movement position from the voltage change based on the electric resistance change of the magnetoresistive effect element 15 is provided inside or outside the housing 2.

As shown in FIGS. 1 to 3, the magnets 4 and 5 are disposed to face each other with a predetermined gap in the height direction (Z direction in the drawing). The facing surface (lower surface) 4a of the first magnet 4 to the second magnet 5 is magnetized to the S pole, and the opposite surface (upper surface) of the first magnet 4 to the facing surface 4a is N. The pole is magnetized. On the other hand, the facing surface (upper surface) 5a of the second magnet 5 with respect to the first magnet 4 is magnetized in the N pole, and is opposite to the facing surface 5a of the second magnet 5 (lower surface). Is magnetized on the S pole.

As shown in FIG. 2, the first magnet 4 has a width dimension T1, and a first center line Ol passing through the center of the width dimension T1 has a length L1 longer than the width dimension T1. It is formed with. Further, both side surfaces 4d and 4e located on both sides of the width dimension T1 are formed in parallel with the center line Ol, and the facing surface 4a of the first magnet 4 is formed in an elongated band shape. The second magnet 5 has a width dimension T2 and a second center line 02 passing through the center of the width dimension T2 is formed with a dimension L2 longer than the width dimension T2. Further, both side surfaces 5d and 5e positioned on both sides of the width dimension T2 are formed in parallel with the center line 02, and the facing surface 5a of the second magnet 5 is formed in an elongated strip shape. The width dimension T1 and the width dimension T2 have the same size, and the length dimension L1 and the length dimension L2 have the same length.

[0033] As shown in FIG. 2, the first magnet 4 has a left end 4b (—end) at the right end 4c (the other end). The second magnet 5 is inclined in the lower direction of the drawing (the opposite direction to the X direction in the drawing) than the right end portion 5c of the second magnet 5 in the upper direction (the X direction in the drawing). As shown in FIG. 2, when viewed from directly above in the height direction (Z direction in the figure), the first center line Ol and the second center line 02 have length dimensions LI and L2. It intersects at the center position. Therefore, the first center line Ol and the second center line 02 are gradually widened from the intersection 20 toward the left end 4b, 5b, and from the intersection 20 toward the right end 4c, 5c. It is separated in the direction (X direction in the figure). As shown in FIG. 2, the first magnet 4 and the second magnet 5 intersect in an X shape.

[0034] As described above, the facing surface (lower surface) 4a of the first magnet 4 is magnetized to the S pole, and the facing surface (upper surface) 5a of the second magnet 5 is magnetized to the N pole. An external magnetic field H is generated toward the facing surface 4a of the first magnet 4 from the force of the facing surface 5a of the second magnet 5.

[0035] Fig. 3 (a) is a cross-sectional view cut along line A shown in Fig. 2, Fig. 3 (b) is a cross-sectional view cut along line B shown in Fig. 2, and Fig. 3 (c) is 2 is a cross-sectional view taken along line C shown in FIG. 2, FIG. 3 (d) is a cross-sectional view taken along line D shown in FIG. 2, and FIG. 3 (e) is taken along line E shown in FIG. A cross-sectional view is shown.

[0036] The cross-sectional portion of Fig. 3 (a) is a place where the first magnet 5 and the second magnet 5 are relatively displaced in the width direction (X direction in the drawing). The first magnet 4 is displaced from the second magnet 5 in the direction opposite to the X direction shown in the figure. Therefore, the direction of the external magnetic field HI from the facing surface 5a of the second magnet 5 to the facing surface 4a of the first magnet 4 is greatly inclined from the Z direction shown in the drawing to the opposite direction to the X direction shown in the drawing. ing. The cross section of FIG. 3 (b) shows that the first magnet 4 and the second magnet 5 are opposed to the second magnet 5 in which the amount of displacement in the X direction is small compared to FIG. 3 (a). The direction of the external magnetic field H2 from the surface 5a toward the opposing surface 4a of the first magnet 4 has a smaller inclination angle from the Z direction in the figure than in FIG. 3 (a). In the cross section of FIG. 3 (c), the first magnet 4 and the second magnet 5 coincide with the height direction (Z direction in the drawing). Therefore, the direction of the external magnetic field H3 from the facing surface 5a of the second magnet 5 to the facing surface 4a of the first magnet 4 coincides with the Z direction shown in the figure. The cross-section of Fig. 3 (d) is the same as Fig. 3 (b), but the amount of displacement of the first magnet 4 and the second magnet 5 in the X direction is small, but is different from Fig. 3 (b). Thus, the first magnet 4 is displaced from the second magnet 5 in the X direction. Therefore, as shown in FIG. 3 (d), the opposing surface 5 of the second magnet 5 The direction of the external magnetic field H4 from the a toward the facing surface 4a of the first magnet 4 is slightly inclined from the Z direction in the figure to the X direction in the figure. The cross-sectional part of Fig. 3 (e) is the same as Fig. 3 (a), but the displacement of the first magnet 4 and the second magnet 5 in the X direction is large, but is different from Fig. 3 (a). Thus, the first magnet 4 is displaced in the X direction in the drawing with respect to the second magnet 5. Therefore, as shown in FIG. 3 (e), the direction of the external magnetic field H5 from the facing surface 5a of the second magnet 5 to the facing surface 4a of the first magnet 4 is changed from the Z direction in the drawing to the X in the drawing. A big tilt in the direction! /, Te! /, Ru.

Thus, the external magnetic field H generated between the first magnet 4 and the second magnet 5 is directed from the left end 4b, 5b toward the right end 4c, 5c, as shown in FIG. As shown in the external magnetic fields H1 to H5 in (a) to (e), the rotational displacement is gradually made.

As shown in FIG. 1, a magnetic detection unit 3 is provided between the first magnet 4 and the second magnet 5, but in FIG. 2 and FIG. 3, the magnetic detection unit 3 is configured. The magnetoresistive effect element 15 is illustrated. As shown in FIG. 3, the magnetoresistive element 15 is not in contact with the first magnet 4 and the second magnet 5 at a predetermined interval in the height direction (Z direction in the drawing). . As shown in FIG. 3, the center of the magnetoresistive effect element 15 in the height direction is located at the center of the height direction (Z direction in the drawing) between the first magnet 4 and the second magnet 5.

As shown in FIG. 2, the magnetoresistive element 15 moves between the first magnet 4 and the second magnet 5 along the Y direction shown in the figure. Here, the moving path 21 of the magnetoresistive element 15 is defined as a moving path at the center position of the magnetoresistive element 15 in the width direction (X direction in the drawing). As shown in FIG. 2, when viewed from directly above in the height direction (Z direction in the figure), the movement path 21 of the magnetoresistive effect element 15 is connected to the first center line Ol of the first magnet 4 and the first center line Ol. It intersects at the intersection 20 of the second centerline 02 of the magnet 2 of 2.

As shown in FIG. 2, the center lines Ol, 02 and the magnetoresistive effect element 15 gradually move from the intersection 20 toward the movement start point 22 and the movement end point 23 of the magnetoresistive effect element 15. The distance between the paths 21 widens in the width direction (X direction in the figure)!

By setting the positional relationship between the moving path 21 of the magnetoresistive effect element 15 and the magnets 4 and 5 as shown in FIG. 2, the magnetoresistive effect element 15 includes the magnets 4 and 4 as shown in FIG. Appropriately move in the rotating magnetic field region where the direction of the external magnetic field H between 5 is rotationally displaced.

[0042] The magnetoresistive element 15 is a GMR element using the giant magnetoresistive effect (GMR effect). is there.

As shown in FIG. 4, the magnetoresistive effect element 15 includes an insulating layer 30, an underlayer 31, an antiferromagnetic layer 32, a fixed magnetic layer 33, a nonmagnetic intermediate layer 34, a free layer on a substrate 7 from below. The magnetic layer 35 and the protective layer 36 are formed in this order using a thin film process such as sputtering. The antiferromagnetic layer 32 / pinned magnetic layer 33 / nonmagnetic intermediate layer 34 / free magnetic layer 35 may be reversely stacked.

[0044] The antiferromagnetic layer 32 is formed of an antiferromagnetic material such as IrMn or PtMn. The pinned magnetic layer 33 is made of a magnetic material such as CoFe or NiFe. The nonmagnetic intermediate layer 34 is formed of a nonmagnetic conductive material such as Cu. The protective layer 36 is made of Ta or the like. The fixed magnetic layer 33 or the free magnetic layer 35 may have, for example, a laminated ferrimagnetic structure.

[0045] Since the antiferromagnetic layer 32 and the pinned magnetic layer 33 are formed in contact with each other, exchange coupling is formed at the interface between the antiferromagnetic layer 32 and the pinned magnetic layer 33 by performing heat treatment in a magnetic field. A magnetic field (Hex) is generated, and the magnetization direction 33a of the fixed magnetic layer 33 is fixed in one direction. In FIG. 4, the magnetization direction 33a is fixed in the Z direction shown.

On the other hand, the magnetization direction 35a of the free magnetic layer 35 receives a bias magnetic field from the pinned magnetic layer 33 in the absence of a magnetic field, and is parallel or antiparallel. Unlike the pinned magnetic layer 33, the free magnetic layer 35 is not pinned in the magnetization direction, and changes in magnetization due to a change in the penetration direction of an external magnetic field. Further, for example, as shown in FIG. 4, it is necessary to provide a hard bias layer (not shown) in order to make the magnetization direction 35a of the free magnetic layer 35 perpendicular to the magnetization direction 33a of the pinned magnetic layer 33. . However, such a hard bias layer is not provided, and the magnetization direction 35a of the free magnetic layer 35 may not be controlled.

As shown in FIG. 4, the magnetoresistive effect element 15 is formed of a laminated structure having a pinned magnetic layer 33 / a nonmagnetic intermediate layer 34 / a free magnetic layer 35, and a laminated interface 37 of each layer is shown in FIG. It is formed in a direction parallel to the Z plane. FIG. 5 is a partially enlarged cross-sectional view showing an enlarged view of FIG. 3 (c). The magnetoresistive effect element 15 is cut from the film thickness center of the free magnetic layer 35. The cut surface of the free magnetic layer 35 shown in FIG. 5 is not the laminated interface 37 shown in FIG. 4, but the cut surface of the free magnetic layer 35 and the laminated interface 37 are in a parallel relationship. In the cross-sectional view of FIG. The same applies to Fig. 7 described later. [0048] The laminated interface 37 is oriented in a direction perpendicular to the facing surfaces 4a, 5a of the first magnet 4 and the second magnet 5. The facing surfaces 15a and 15b of the magnetoresistive element 15 facing the magnets 4 and 5 are oriented in parallel to the facing surfaces 4a and 5a of the magnets 4 and 5, respectively. Therefore, the magnetoresistive effect element 15 has an external magnetic field H1 to H5 that rotates and displaces between the first magnet 4 and the second magnet 5 in a plane direction parallel to the laminated interface 37 (X-Z plane direction in the figure). It becomes the positional relationship that can enter.

The magnetoresistive effect element 15 is excellent in the ability to read the external magnetic field H from a direction parallel to the laminated interface 37 entering the free magnetic layer 35. Since the external magnetic fields H1 to H5 described with reference to FIG. 3 are rotationally displaced in the X-Z plane shown in FIG. 3, the magnetoresistive effect element 15 is obtained by matching the laminated interface 37 with the rotationally displaced surface of the external magnetic field H. The external magnetic field HI to H5, which is rotationally displaced from the plane direction parallel to the laminated interface, appropriately enters.

As shown in FIG. 5, when the film thickness center (the center in the Y direction in the figure) of the free magnetic layer 35 constituting the magnetoresistive effect element 15 moves to the position of the intersection 20 shown in FIG. Magnetization direction of the free magnetic layer 35 under the influence of an external magnetic field H3 generated in the height direction (Z direction in the figure) from the facing surface 5a of the magnet 5 to the facing surface 4a of the first magnet 4 35a varies in the Z direction.

Similarly, when the magnetoresistive effect element 15 is moved to the positions shown in FIGS. 3A, 3B, 3D, and 3E, the free magnetic layer 35 is illustrated in the Z direction. An external magnetic field inclined in the X direction or in the direction opposite to the X direction shown in the figure enters, and the magnetization direction 35a of the free magnetic layer 35 changes as shown by the dotted line in FIG. The electric resistance value changes depending on the relationship between the variable magnetization direction 35 a of the free magnetic layer 35 and the fixed magnetization direction 33 a of the fixed magnetic layer 33.

In the embodiment shown in FIGS. 1 to 5, a magnetoresistive effect element 15 is provided between the first magnet 4 and the second magnet 5, and the laminated interface of the laminated structure of the magnetoresistive effect element 15 37 is directed in a direction orthogonal to the facing surfaces 4a and 5a of the first magnet 4 and the second magnet 5.

The first magnet 4 and the second magnet 5 are arranged in the space between the magnets 4 and 5 from the left end portions 4b and 5b of the magnets 4 and 5 toward the right end portions 4c and 5c. The shape and arrangement are determined so that an external magnetic field region that rotates and displaces in a plane parallel to the laminated interface 37 is formed. The magnetoresistive effect element 15 is the center in the width direction between the center lines Ol and 02 of the magnets 4 and 5 so as to move linearly in the rotating magnetic field region, and is in the height direction between the magnets 4 and 5. It is moved and supported at the center.

As a result, when the magnetoresistive effect element 15 linearly moves in the Y direction shown in the figure from the starting point 22 to the end point 23 shown in FIG. 2, the magnetoresistive effect element 15 enters the free magnetic layer 35 constituting the magnetoresistive effect element 15. As the direction of the external magnetic field H changes gradually, the electric resistance value changes gradually, and the moving position is detected by the output change based on the change in the electric resistance value. According to the present embodiment, when the magnetoresistive effect element 15 is moved from the starting point 22 to the ending point 23 as compared with the conventional case, the electric resistance value can be gradually changed, and the position detection linearity (Naozumi) Property) can be improved.

In the embodiment shown in FIG. 1 to FIG. 5, one of the first magnet 4 and the second magnet 5 may be a yoke. However, if one of them is a yoke, a disturbance magnetic field extending from the outside to the inside of the movement sensor 1 affects the external magnetic field H that is rotationally displaced between the magnets 4 and 5, and the direction of the external magnetic field H is disturbed. It is preferable to use magnets 4 and 5 for both because the position detection linearity is easily reduced.

[0056] The movement sensor can also be configured using only one magnet. FIG. 6 is a partial plan view showing the positional relationship between the magnetoresistive element and the magnet constituting the movement sensor of the second embodiment, and FIG. 7 shows the magnetoresistive effect along the F line, G line, and H line shown in FIG. It is the fragmentary sectional view which cut | disconnected the element and the magnet along the height direction (illustrated Z direction), and was seen from the arrow direction.

As shown in FIG. 6, the magnet 40 is formed with a width dimension of T3, and the length dimension L3 of the center line 03 passing through the center of the width dimension T3 is longer than the width dimension T3. Yes. Further, both side surfaces 40b and 40c located on both sides of the width dimension T3 extend in parallel to the center line 03, and the opposing surface 40a of the magnet 40 to the magnetoresistive element 41 is formed in a rectangular shape.

In this embodiment, as shown in FIG. 7, the surface (opposing surface) 40a of the magnet 40 is magnetized to the N pole and the back surface is magnetized to the S pole.

The magnetoresistive effect element 41 shown in FIGS. 6 and 7 is formed with the same laminated structure as the magnetoresistive effect element 15 shown in FIG. In the magnetoresistive effect element 41, as in FIG. 5, the laminated interface 42 of the laminated structure is in a direction (height direction) orthogonal to the facing surface 40a of the magnet 40 facing the magnetoresistive effect element 41. In addition, it is oriented in the width direction (X direction in the figure). As a result, the external magnetic field H from the magnet 40 enters the magnetoresistive element 41 from a plane direction (X-Z plane direction in the drawing) parallel to the laminated interface 42.

As shown in FIG. 6, the center line 03 of the magnet 40 is formed along the Y direction in the figure. On the other hand, as shown in FIG. 6, the moving path 43 of the magnetoresistive effect element 41 is a linear path diagonally extending in the lower left direction from the force on the upper left direction of the paper with respect to the center line 03. The moving path 43 of the effect element 41 and the center line 03 of the magnet 40 intersect at the center of the magnet 40 in the length direction (Y direction in the drawing).

In this way, from the intersection 44 toward the starting point 45 and the end point 46 of the magnetoresistive effect element 41, the width direction between the center line 03 and the moving path 43 of the magnetoresistive effect element 41 (illustrated) The magnetoresistive effect element 41 and the magnet 40 are arranged so that the interval in the (X direction) is widened.

FIG. 7 (a) shows a magnetoresistive element and a magnet cut in the height direction from the line FF in FIG.

Fig. 7 (b) is a partial cross-sectional view of the magnetoresistive effect element 40 and the magnet 40 cut from the G-G line in Fig. 6 in the height direction. Fig. 7 (c) is a H- A partial sectional view of the magnetoresistive element and the magnet 40 cut in the height direction from the H line is shown.

[0064] As shown in FIG. 7 (a), when the center of the free magnetic layer 47 of the magnetoresistive element 41 in the film thickness direction (Y direction in the figure) is positioned on the leftmost magnet 40 in FIG. The external magnetic field H6 dominates into the magnetic layer 47 almost from the X direction shown in the figure.

[0065] When the magnetoresistive element 41 moves on the moving path 43 from the starting point 45 toward the intersection 44, the external magnetic field from the magnet 40 entering from the plane direction parallel to the laminated interface 42 is illustrated as X As shown in FIG. 7B, the center of the free magnetic layer of the magnetoresistive effect element 41 in the film thickness direction (Y direction in the figure) is gradually increased. When the position on the intersection 44 is reached, an external magnetic field H7 in the Z direction shown in FIG.

Next, the magnetoresistive element 41 moves from the position of the intersection 44 toward the end point 46. When moving, the external magnetic field from the magnet 40 entering from the plane direction parallel to the laminated interface 42 begins to increase in vector components gradually moving from the Z direction shown in the figure to the direction opposite to the X direction shown in FIG. ), When the film thickness center of the free magnetic layer of the magnetoresistive effect element 41 is located on the rightmost magnet 40 in the figure, the free magnetic layer has an external magnetic field H8 in a direction almost opposite to the X direction in the figure. Invades dominantly.

As shown in FIG. 6 and FIG. 7, even if there are a single magnet 40, the movement path of the magnetoresistive effect element 41

43 and a center line 03 passing through the center in the width direction of the magnet 40 are crossed from the oblique direction so that the movement of the magnetoresistive effect element 41 leads to a parallel to the laminated interface 42 of the magnetoresistive effect element 41. The external magnetic field H from the magnet 40 that also penetrates the surface force is rotationally displaced. As the magnetoresistive effect element 41 moves, the magnetization direction of the free magnetic layer 47 fluctuates in the direction of the external magnetic field H that is rotationally displaced, and as a result, the electric resistance value of the magnetoresistive effect element 41 is fluctuate. At this time, since the magnetization direction of the free magnetic layer 47 gradually changes as the magnetoresistive element 41 moves, the electric resistance value of the magnetoresistive element 41 also gradually changes, and linearity Position detection with high (linearity) can be performed.

[0068] However, as shown in FIGS. 6 and 7, the number of magnets 40 is less than one, and two magnets 4 and 5 are prepared and rotated between magnets 4 and 5 as in the embodiment shown in FIGS. Artificial creation of magnetic field area The external magnetic field can be rotated and displaced gradually and in a linear direction from 1S, and the position detection linearity (linearity) can be further improved. It is.

If the above-described embodiment is used, as shown in FIG. 8, two sets of magnets 50 and 51 are prepared in the orthogonal direction so that the magnetoresistance supported by the X-axis 60 and the Y-axis 61 is obtained. It is also possible to detect the movement of the effect element 53 in two directions, the X direction and the Y direction.

[0070] In any of the movement sensors described above, the magnetoresistive element is moved and supported, and the magnet is fixedly supported. However, if the magnetoresistive effect element is fixedly supported and the magnet is moved, for example, in order to secure the relative movement distance from the start point 22 to the end point 23 of the magnetoresistive effect element 15 in FIG. Therefore, it is necessary to move and support the magnetoresistive effect element and to fix and support the magnet in a simple configuration. This is suitable because it can be realized. In the above embodiment, the movement path of the magnetoresistive effect element is! / And the deviation is linear, but it may be other than linear. However, a straight line is preferable because high linearity (linearity) of position detection can be secured.

[0072] In addition to the GMR element using the giant magnetoresistive effect (GMR effect), the magnetoresistive element is an AMR element using the anisotropic magnetoresistive effect (AMR effect), and the tunnel magnetoresistive effect (TMR effect). Even a TMR element using

[0073] The movement sensor in this embodiment can be used, for example, as a mixer fader or a slide volume for a control console.

Brief Description of Drawings

[0074] FIG. 1 is a partial perspective view for showing an internal structure of a movement sensor in the present embodiment;

FIG. 2 is a partial plan view for showing the positional relationship between the moving direction of the magnetoresistive effect element constituting the movement sensor shown in FIG. 1 and the magnet and the magnetoresistive effect element;

[FIG. 3] (a) to (e) show the height direction of the magnetoresistive element and the magnet along each line when the magnetoresistive element moves from the position on the A line to the position on the E line shown in FIG. A partial cross-sectional view as seen from the direction of the arrow,

FIG. 4 is a cross-sectional view from the film thickness direction of the laminated structure of magnetoresistive elements,

[Fig. 5] Enlarged sectional view of Fig. 3 (c),

FIG. 6 is a partial plan view showing the positional relationship between a magnetoresistive element and a magnet constituting the movement sensor of the second embodiment,

[FIG. 7] When the magnetoresistive effect element moves to the position on the F line, G line, and H line shown in FIG. 6, the magnetoresistive effect element and the magnet are cut in the height direction along each line, and from the arrow direction. A partial cross-sectional view,

FIG. 8 is a partial plan view showing the positional relationship between a magnetoresistive element and a magnet constituting the movement sensor of the third embodiment,

Explanation of symbols

[0075] 1 Movement sensor

2 Enclosure

3 Magnetic detector 4, 5, 40, 50, 51 Magnet

15, 41, 53 Magnetoresistive element

20, 44 intersection

21, 43 Route

22, 45 Starting point

23, 46 End point

32 Antiferromagnetic layer

33 Fixed magnetic layer

34 Nonmagnetic interlayer

35, 47 Free magnetic layer

35a Magnetization direction (of free magnetic layer)

37, 42 Laminated interface

H, H1 ~ H8 External magnetic field

〇 1 to 03 (pass through the center in the width direction of the magnet)

Claims

The scope of the claims

[1] A magnetoresistive element having a laminated structure using a magnetoresistive effect in which an electric resistance changes in response to a change in direction of an external magnetic field, and a magnet for generating the external magnetic field, and the magnetoresistive element And one of the magnets is movably supported, and the magnetoresistive element and the magnet are spaced apart from each other in the height direction, and when viewed from directly above the height direction, A center line passing through the center and the relative movement path of the magnetoresistive element intersect in the middle, and gradually the center from the intersection toward the starting point of relative movement of the magnetoresistive element and the end point of relative movement. The line and the magnetoresistive effect element are arranged to face each other so that the distance between the relative movement paths of the magnetoresistive effect element is widened in the width direction,

With the relative movement of the magnetoresistive effect element, the penetration direction of the external magnetic field from a plane direction parallel to the laminated interface entering the laminated structure is rotationally displaced, and the electric resistance value of the magnetoresistive effect element A movement sensor, characterized in that the movement position is detected by changing.

[2] The magnet has a centerline length passing through the center of the width dimension longer than the dimension in the width direction, and both side surfaces located on both sides of the width dimension extend in a direction parallel to the centerline. The movement sensor according to claim 1, wherein the movement sensor is formed in a shape!

[3] The movement sensor according to claim 1, wherein the magnetoresistive effect element relatively moves linearly.

4. The movement sensor according to claim 1, wherein the magnetoresistive element is movably supported and the magnet is fixedly arranged.

[5] In the magnetoresistive effect element, the laminated interface of the laminated structure is oriented in a direction perpendicular to the facing surface of the magnet facing the magnetoresistive effect element, and the facing surface of the magnet is single. The movement sensor according to claim 1, wherein the movement sensor is! /.

[6] The first magnetic member and the second magnetic member are opposed to each other with a gap in the height direction, and the first magnetic member and the second magnetic member are When viewed from above, the first center line passing through the center of the width dimension of the first magnetic member and the second center line passing through the center of the width dimension of the second magnetic member intersect in the middle. And the first center line and the second center line are directed from the intersection toward one end and from the intersection toward the other end. And at least one of the first magnetic member and the second magnetic member is formed of the magnet.

In the space between the first magnetic member and the second magnetic member, the directional force of the external magnetic field generated from the facing surface of one magnetic member toward the facing surface of the other magnetic member. A rotating magnetic field region that gradually rotates is formed from one end side to the other end side of the magnetic member and the second magnetic member, and the magnetoresistive effect element has a laminated interface force of the laminated structure and the magnetic force. A movement sensor that is directed in a direction orthogonal to the surface of the member facing the magnetoresistive effect element, and that relatively moves so as to pass through the rotating magnetic field region from the one end side toward the other end side. .

[7] The opposing surfaces of the first magnetic member and the second magnetic member are band-shaped, intersecting in an X shape when viewed from directly above the height direction, and the magnetoresistive effect When viewed from directly above the height direction, the element has a straight line in the center in the width direction between the first center line of the first magnetic member and the second center line of the second magnetic member. The movement sensor according to claim 6, wherein the movement sensor is relatively moved.

[8] The first magnetic member and the second magnetic member are both formed of magnets, and the opposing surface of the first magnetic member and the opposing surface of the second magnetic member are magnetized to have different polarities. The movement sensor according to claim 6.