JP2010019552A - Motion sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a contactless motion sensor using a magnetoresistive effect element, and especially a motion sensor having an improved linearity of position detection. <P>SOLUTION: A first magnet 4 and a second magnet 5 are crossed into the shape of X, 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 rotated and displaced is formed from their left-side ends 4b, 5b over to right-side ends 4c, 5c, and the megnetoresistive element 15 is movably supported so as to pass the rotating magnetic field region. Therefore, with its movement the direction of magnetization of the free magnetic layer of the magnetoresitive element 15 gradually varies. Consequently, the linearity of the position detection can be improved. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

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

  The MR element using the magnetoresistive effect is used for a movement sensor described in Patent Document 1 below. The MR element can detect a change in the direction of an external magnetic field with high accuracy based on a change in electrical resistance accompanying the change in direction, and can detect the change regardless of environmental changes or a decrease in magnetic force of a magnet. Higher performance and longer life can be expected compared to an element that reads changes in magnetic field strength of an external magnetic field.

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

  In such an arrangement, when the magnetic detection element is arranged near the magnetic pole of the permanent magnet, the magnetic detection element is orthogonal to the surface of the magnetic detection element facing the permanent magnet from the permanent magnet. When the magnetic detection element is located between the magnetic poles as shown in FIG. 7 of Patent Document 1, an external magnetic field in a direction parallel to the facing surface of the magnetic detection element enters. To do.

Thus, in Patent Document 1, since the direction of the external magnetic field penetrating into the magnetic detection element is changed by moving the permanent magnet, the magnetic detection element is an MR element using a magnetoresistive effect. A change in the direction of the external magnetic field changes the electric resistance value of the magnetic detection element.
JP-A-5-280916

  However, in the invention described in Patent Document 1, the external magnetic field region that penetrates in the direction parallel to the facing surface of the magnetic detection element is too long, and the position detection linearity (linearity) cannot be improved appropriately. it is conceivable that.

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

  Accordingly, 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, it is possible to improve the linearity (linearity) of position detection. The object is to provide a movement sensor.

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 respect to a change in direction of an external magnetic field, and a magnet for generating the external magnetic field,
One of the magnetoresistive effect element and the magnet is movably supported,
The magnetoresistive element and the magnet are spaced apart in the 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 magnetoresistive element The relative movement path intersects in the middle, and the distance between the center line and the relative movement path of the magnetoresistive element gradually increases from the intersection toward the starting point of relative movement of the magnetoresistive element and the end point of relative movement. Opposed to spread in the width direction,
With the relative movement of the magnetoresistive effect element, the penetration direction of the external magnetic field from the plane direction parallel to the laminated interface penetrating into the laminated structure is rotationally displaced, and the electric resistance value of the magnetoresistive effect element changes. Thus, the movement position is detected.

  In the present invention, with the above-described configuration, position detection linearity (linearity) can be improved in a non-contact type movement sensor using a magnetoresistive effect element as compared with the related art.

  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, and the starting point of the relative movement of the magnetoresistive element from the intersection and the relative movement The magnetoresistive effect element and the magnet are arranged to face each other so that the distance between the center line and the relative movement path of the magnetoresistive effect element gradually increases in the width direction.

  When the center line of the magnet and the relative movement path of the magnetoresistive effect element coincide with each other as in the prior art, the direction of the external magnetic field entering the magnetoresistive effect element is substantially constant near the center of the magnet. As a result, the linearity (linearity) of position detection could not be improved.

  On the other hand, in the present invention, 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. The resistance effect element is always in a position that fluctuates with respect to the center line of the magnet, and accordingly, with the relative movement of the magnetoresistance effect element, the resistance effect element is externally viewed from a plane direction parallel to the laminated interface of the magnetoresistance effect element. The intrusion direction of the magnetic field can be gradually displaced.

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

  In the present invention, the magnet has a center line length passing through the center in the width direction being longer than the dimension in the width direction, and both side surfaces located on both sides of the center line are in a direction parallel to the center line. As the magnetoresistive effect element is formed in an extending shape, the penetration direction of the external magnetic field from the plane direction parallel to the laminated interface of the magnetoresistive effect element can be appropriately rotationally displaced with the relative movement of the magnetoresistive effect element. It is possible and suitable.

  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 movably supported and the magnet is fixedly arranged, it is possible to reduce the size with a simple configuration.

  In the present invention, the magnetoresistive effect element is such that a laminated interface of the laminated structure is oriented in a direction orthogonal to a face of the magnet facing the magnetoresistive effect element, and the face of the magnet is single. It is preferable that the magnetic pole face be With such a configuration, the relative movement of the magnetoresistive element from the starting point of the relative movement of the magnetoresistive effect element toward the intersection and the end point is parallel to the stacked interface of the magnetoresistive effect element. The penetration direction of the external magnetic field from the surface direction can be more appropriately rotationally displaced.

In the present invention, the first magnetic member and the second magnetic member are opposed to each other at an interval in the height direction, and the first magnetic member and the second magnetic member are arranged in the height direction. When viewed from directly above, 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 are in the middle. 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 toward the one end direction and from the intersection toward the other end direction. 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 direction of the external magnetic field generated from the facing surface of one magnetic member toward the facing surface of the other magnetic member is the first magnetic member. A rotating magnetic field region that is gradually rotated and displaced from one end side to the other end side of the magnetic member and the second magnetic member is formed, and the magnetoresistive element has a layered interface of the layered structure in which the layered interface is magnetic. 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.

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

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

  In the present invention, the opposing surfaces of the first magnetic member and the second magnetic member are band-shaped and intersect in an X shape when viewed from directly above the height direction, When the effect element is viewed from directly above in the height direction, 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 is a straight line. It is possible to use a linear movement sensor that improves the linearity (linearity) of position detection more effectively.

  In the present invention, 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. Therefore, 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 it is possible to improve the linearity of position detection.

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

  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 positions of the magnet and the magnetoresistive effect element. 3 (a) to 3 (e) are partial plan views for showing the relationship, and the magnetoresistive effect element and the magnet along each line when the magnetoresistive effect element moves from the position A to the position E shown in FIG. FIG. 4 is a sectional view from the film thickness direction of the laminated structure of the magnetoresistive effect element, FIG. 5 is an enlarged sectional view of FIG. It is.

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

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

  As shown in FIG. 1, a linear opening 6 is formed in the upper surface 2a of the housing 2 along the Y direction in the figure. 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.

  The substrate 7 is supported by two rail portions 9 and 10 extending in parallel in the length direction (Y direction shown in the drawing) with a predetermined interval in the width direction (X direction shown in the drawing), and the lever 8 is shown in the drawing. By moving in the Y direction, the substrate 7 moves in the Y direction in the drawing 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 through 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 a movement position from a voltage change based on a change in electric resistance 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 arranged to face each other at a predetermined interval in the height direction (Z direction in the drawing). The opposing surface (lower surface) 4a of the first magnet 4 with the second magnet 5 is magnetized to the S pole, and the opposite surface (upper surface) of the first magnet 4 with respect to the opposing 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 to the N pole, and the opposite surface (lower surface) of the facing surface 5a of the second magnet 5 is formed. S pole is magnetized.

  As shown in FIG. 2, the first magnet 4 is formed with a width dimension T1, and a first center line O1 passing through the center of the width dimension T1 is formed with a length dimension L1 rather than the width dimension T1. ing. Further, both side surfaces 4d and 4e positioned on both sides of the width dimension T1 are formed in parallel with the center line O1, 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 of T2, and a second center line O2 passing through the center of the width dimension T2 is formed with a length dimension L2 that is greater than the width dimension T2. Further, both side surfaces 5d and 5e located on both sides of the width dimension T2 are formed in parallel with the center line O2, 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 are the same, and the length dimension L1 and the length dimension L2 are the same length.

  As shown in FIG. 2, the first magnet 4 has a left end 4b (one end) inclined more upward in the drawing (X direction in the drawing) than the right end 4c (the other end), and the second magnet 4 The left end 5b of the magnet 5 is inclined to the lower side of the drawing (the direction opposite to the X direction in the drawing) than the right end 5c. As shown in FIG. 2, when viewed from directly above in the height direction (Z direction in the drawing), the first center line O1 and the second center line O2 are the centers of the length dimensions L1 and L2. Cross at the position. Therefore, the first center line O1 and the second center line O2 are gradually widened from the intersection 20 toward the left end portions 4b and 5b and from the intersection 20 toward the right end portions 4c and 5c. It is away 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.

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

  3A is a cross-sectional view taken along the line A shown in FIG. 2, FIG. 3B is a cross-sectional view taken along the line B shown in FIG. 2, and FIG. FIG. 3D is a cross-sectional view cut along line D shown in FIG. 2, and FIG. 3E is a cross-sectional view cut along line E shown in FIG. Show.

  The cross-sectional portion of FIG. 3A is a place where the first magnet and the second magnet 5 are relatively large and 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 illustrated X direction. Therefore, the direction of the external magnetic field H1 from the facing surface 5a of the second magnet 5 toward the facing surface 4a of the first magnet 4 is greatly inclined from the Z direction to the opposite direction to the X direction. The cross section of FIG. 3B shows that the first magnet 4 and the second magnet 5 have a smaller amount of displacement in the X direction shown in FIG. The direction of the external magnetic field H2 from 5a toward the facing surface 4a of the first magnet 4 has a smaller inclination angle from the Z direction shown in the figure than in FIG. 3C, 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 toward the facing surface 4a of the first magnet 4 coincides with the Z direction shown in the figure. The cross-sectional portion 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 shifted in the X direction in the drawing with respect to the second magnet 5. Therefore, as shown in FIG. 3D, the direction of the external magnetic field H4 from the facing surface 5a of the second magnet 5 toward the facing surface 4a of the first magnet 4 is smaller from the Z direction shown in the drawing to the X direction shown in the drawing. Tilted. The cross-sectional portion of FIG. 3 (e) is similar to FIG. 3 (a), but the amount of displacement of the first magnet 4 and the second magnet 5 in the illustrated X direction is large, but is different from FIG. 3 (a). Thus, the first magnet 4 is shifted 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 toward the facing surface 4a of the first magnet 4 is greatly increased from the Z direction to the X direction. Tilted.

  As described above, the external magnetic field H generated between the first magnet 4 and the second magnet 5 is directed from the left end portions 4b and 5b toward the right end portions 4c and 5c, as shown in FIG. As shown in the external magnetic fields H1 to H5 in (e) 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. In FIGS. 2 and 3, the magnetic elements constituting the magnetic detection unit 3 are provided. A resistance effect element 15 is illustrated. As shown in FIG. 3, the magnetoresistive effect element 15 is not in contact with the first magnet 4 and the second magnet 5 with a predetermined distance 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 effect 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 effect element 15 is defined as a moving path at the center position in the width direction (X direction in the drawing) of the magnetoresistive effect element 15. As shown in FIG. 2, when viewed from directly above in the height direction (Z direction in the drawing), the movement path 21 of the magnetoresistive effect element 15 is connected to the first center line O <b> 1 of the first magnet 4 and the first center line O <b> 1. The second magnet 5 intersects at the intersection 20 with the second center line O2.

  As shown in FIG. 2, gradually from the intersection 20 toward the movement start point 22 and the movement end point 23 of the magnetoresistive effect element 15 between the center lines O1 and O2 and the movement path 21 of the magnetoresistive effect element 15. Is widened 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 is placed between the magnets 4 and 5 as shown in FIG. The rotating magnetic field region in which the direction of the external magnetic field H is rotationally displaced is appropriately moved.

  The magnetoresistive effect element 15 is a GMR element using a giant magnetoresistive effect (GMR effect).

  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, and a free magnetic layer 35 on the substrate 7 from below. The protective layer 36 is 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.

  The antiferromagnetic layer 32 is formed of an antiferromagnetic material such as IrMn or PtMn. The pinned magnetic layer 33 and the free magnetic layer 35 are formed 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 pinned magnetic layer 33 and the free magnetic layer 35 may have a laminated ferrimagnetic structure, for example.

  Since the antiferromagnetic layer 32 and the pinned magnetic layer 33 are formed in contact with each other, an exchange coupling magnetic field (Hex) is formed at the interface between the antiferromagnetic layer 32 and the pinned magnetic layer 33 by performing a heat treatment in a magnetic field. The magnetization direction 33a of the pinned magnetic layer 33 is pinned 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 is parallel or anti-parallel when the magnetization direction 33a of the pinned magnetic layer 33 is subjected to a bias magnetic field by the pinned magnetic layer 33 when there is no magnetic field. Unlike the pinned magnetic layer 33, the magnetization direction of the free magnetic layer 35 is not fixed, and the magnetization of the free magnetic layer 35 is changed by a change in the penetration direction of the 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 orthogonal 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 by a laminated structure having a pinned magnetic layer 33 / non-magnetic intermediate layer 34 / free magnetic layer 35, and a laminated interface 37 of each layer has an XZ plane shown in the figure. They are formed in parallel directions. FIG. 5 is a partially enlarged sectional view showing FIG. 3C in an enlarged manner, and 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 stacked interface 37 shown in FIG. 4, but the cut surface of the free magnetic layer 35 and the stacked interface 37 are in a parallel relationship. In the cross-sectional view of FIG. The same applies to FIG. 7 described later.

  The laminated interface 37 is oriented in a direction perpendicular to the facing surfaces 4 a and 5 a of the first magnet 4 and the second magnet 5. Further, the opposing surfaces 15a and 15b of the magnetoresistive element 15 facing the magnets 4 and 5 are oriented in a direction parallel to the opposing surfaces 4a and 5a of the magnets 4 and 5, respectively. Therefore, external magnetic fields H1 to H5 that are rotationally displaced between the first magnet 4 and the second magnet 5 in the plane direction (XZ plane direction in the drawing) parallel to the laminated interface 37 enter the magnetoresistive effect element 15. The positional relationship is possible.

  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 XZ plane shown in the figure, 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 fields H1 to H5 that are rotationally displaced from the plane direction parallel to the laminated interface appropriately enter.

  As shown in FIG. 5, when the film thickness center (center in the Y direction in the figure) of the free magnetic layer 35 constituting the magnetoresistive element 15 moves to the position of the intersection 20 shown in FIG. 5, the magnetization direction 35a of the free magnetic layer 35 is illustrated under the influence of an external magnetic field H3 generated in the height direction (Z direction in the drawing) from the facing surface 5a to the facing surface 4a of the first magnet 4. Fluctuates 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 moved from the illustrated Z direction to the illustrated X direction, Alternatively, external magnetic fields inclined in the direction opposite to the X direction shown in the figure enter, 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 element 15 is provided between the first magnet 4 and the second magnet 5, and the laminated interface 37 of the laminated structure of the magnetoresistive element 15 is The first magnet 4 and the second magnet 5 are oriented in a direction orthogonal to the facing surfaces 4a and 5a.

  The first magnet 4 and the second magnet 5 are stacked 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 as to form a region of an external magnetic field that is rotationally displaced in a plane parallel to the interface 37, and the magnetoresistive effect element 15 moves linearly in the rotational magnetic field region. 4 and 5 is centered in the width direction between the center lines O1 and O2, and is supported by movement at the center in the height direction between the magnets 4 and 5.

  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 external magnetic field H entering the free magnetic layer 35 constituting the magnetoresistive effect element 15 is increased. As the direction changes gradually, the electric resistance value changes gradually, and the movement position is detected by the output change based on the change in the electric resistance value. According to this 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 linearity (linearity) of position detection is achieved. It is possible to improve.

  In the embodiment shown in FIGS. 1 to 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. Since it becomes easy and the linearity of a position detection tends to fall, it is suitable to use the magnets 4 and 5 for both.

  Moreover, a movement sensor can also be comprised 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 is a 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 (Z direction of illustration), and was seen from the arrow direction.

  As shown in FIG. 6, the magnet 40 is formed with a width dimension T3, and the length L3 of the center line O3 passing through the center of the width dimension T3 is longer than the width dimension T3. Further, both side surfaces 40b and 40c located on both sides of the width dimension T3 extend in parallel with the center line O3, and a surface 40a of the magnet 40 facing 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 has the same laminated structure as the magnetoresistive effect element 15 shown in FIG.

  As in FIG. 5, the magnetoresistive element 41 has a width in the direction (height direction) in which the laminated interface 42 of the laminated structure is orthogonal to the facing surface 40a of the magnet 40 with the magnetoresistive element 41. It is directed in the 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 (XZ plane direction in the drawing) parallel to the laminated interface 42.

  As shown in FIG. 6, the center line O3 of the magnet 40 is formed along the Y direction in the drawing. On the other hand, as shown in FIG. 6, the moving path 43 of the magnetoresistive effect element 41 is a linear path in an oblique direction from the upper left direction to the lower right direction with respect to the center line O3. The movement path 43 and the center line O3 of the magnet 40 intersect at the center of the magnet 40 in the length direction (Y direction in the drawing).

  In this way, gradually from the intersection 44 toward the start point 45 and the end point 46 of the magnetoresistive effect element 41 in the width direction (X direction in the drawing) between the center line O3 and the moving path 43 of the magnetoresistive effect element 41. The magnetoresistive effect element 41 and the magnet 40 are arranged so that the interval is widened.

  7A is a partial cross-sectional view of the magnetoresistive element and the magnet 40 cut in the height direction from the line FF in FIG. 6, and FIG. 7B is the height from the line GG in FIG. FIG. 7C is a partial cross-sectional view of the magnetoresistive effect element and the magnet 40 cut in the height direction from the line HH in FIG. 6. Yes.

  As shown in FIG. 7A, when the center in the film thickness direction (Y direction in the figure) of the free magnetic layer 47 of the magnetoresistive element 41 is positioned on the leftmost magnet 40 in FIG. The external magnetic field H6 invades predominantly from the X direction shown in the figure.

  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 stacked interface 42 gradually increases from the X direction in the figure. The vector component toward the Z direction shown in the figure starts to increase, and eventually the center in the film thickness direction (Y direction shown in the figure) of the free magnetic layer of the magnetoresistive element 41 is on the intersection 44 as shown in FIG. When the position is reached, an external magnetic field H7 in the Z direction shown in FIG.

  Next, when the magnetoresistive effect element 41 moves from the position of the intersection 44 toward the end point 46, the external magnetic field from the magnet 40 entering from the plane direction parallel to the laminated interface 42 gradually increases from the Z direction in the figure. When the vector component directed in the direction opposite to the X direction in the figure starts to increase, and the film thickness center of the free magnetic layer of the magnetoresistive effect element 41 is positioned on the rightmost magnet 40 in the figure, as shown in FIG. In the free magnetic layer, an external magnetic field H8 in a direction almost opposite to the X direction shown in FIG.

  As shown in FIGS. 6 and 7, even if there is only one magnet 40, the moving path 43 of the magnetoresistive effect element 41 and the center line O3 passing through the center in the width direction of the magnet 40 are intersected from an oblique direction, thereby As the magnetoresistive effect element 41 moves, the external magnetic field H from the magnet 40 entering from a plane direction parallel to the laminated interface 42 of the magnetoresistive effect element 41 is rotationally displaced. As the magnetoresistive effect element 41 is moved, the magnetization direction of the free magnetic layer 47 changes in the direction of the external magnetic field H that is rotationally displaced, whereby the electric resistance value of the magnetoresistive effect element 41 changes. At this time, the magnetization direction of the free magnetic layer 47 gradually changes with the movement of the magnetoresistive effect element 41, so that the electric resistance value of the magnetoresistive effect element 41 also gradually changes and linearity (linear Position detection can be performed.

  However, as shown in FIG. 6 and FIG. 7, the number of magnets 40 is one, and two magnets 4 and 5 are prepared as in the embodiment shown in FIG. 1 to FIG. It is preferable to produce artificially because the external magnetic field can be rotated and displaced gradually and with a linear direction, and the linearity (linearity) of position detection can be improved. .

  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 magnetoresistive effect element 53 supported by the X axis 60 and the Y axis 61 It is also possible to detect the movement in the biaxial direction of the X direction and the Y direction.

  In any of the above-described movement sensors, the magnetoresistive effect 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. Since a movement space approximately twice the relative movement distance is required to ensure the movement, the movement sensor can be downsized with a simple structure by supporting the magnetoresistive element and supporting the magnet fixedly. It can be realized and is preferable.

  In the above embodiment, the movement path of the magnetoresistive element is linear, but may be other than linear. However, the straight line shape is preferable because it can ensure high position detection linearity.

  In addition to the GMR element using the giant magnetoresistive effect (GMR effect), the magnetoresistive effect element is an AMR element using an anisotropic magnetoresistive effect (AMR effect), and a TMR using the tunnel magnetoresistive effect (TMR effect). It may be an element.

  The movement sensor in the present embodiment can be used, for example, as a mixer fader or a slide volume for control.

The partial perspective view for showing the internal structure of the movement sensor in this embodiment, FIG. 2 is a partial plan view for showing a positional relationship between a moving direction of the magnetoresistive effect element constituting the movement sensor shown in FIG. 1 and a magnet and the magnetoresistive effect element; (A)-(e), when a magnetoresistive effect element moves from the position on the A line to the position on the E line shown in FIG. 2, the magnetoresistive effect element and the magnet are cut in the height direction along each line, and the arrows Partial sectional view seen from the direction, Sectional drawing from the film thickness direction of the laminated structure of the magnetoresistive effect element, FIG. 3 (c) is an enlarged sectional view, The partial top view which shows the positional relationship of the magnetoresistive effect element and magnet which comprise the movement sensor of 2nd Embodiment, When the magnetoresistive effect element moves to the position on the F line, the G line, and the H line shown in FIG. 6, the magnetoresistive effect element and the magnet are cut in the height direction along each line, and a partial cross section seen from the arrow direction Figure, The fragmentary top view which shows the positional relationship of the magnetoresistive effect element and magnet which comprise the movement sensor of 3rd Embodiment,

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Movement sensor 2 Housing | casing 3 Magnetic detection part 4, 5, 40, 50, 51 Magnet 15,41,53 Magnetoresistive element 20,44 Intersection 21,43 Movement path 22,45 Starting point 23,46 End point 32 Anti-strong Magnetic layer 33 Pinned magnetic layer 34 Nonmagnetic intermediate layer 35, 47 Free magnetic layer 35a (Free magnetic layer) Magnetization direction 37, 42 Stack interface H, H1-H8 External magnetic field O1-O3 (passes the center in the width direction of the magnet) ) Center line

Claims (8)

A magnetoresistive element having a laminated structure using a magnetoresistive effect in which an electric resistance changes with respect to a change in direction of an external magnetic field, and a magnet for generating the external magnetic field,
One of the magnetoresistive effect element and the magnet is movably supported,
The magnetoresistive element and the magnet are spaced apart in the 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 magnetoresistive element The relative movement path intersects in the middle, and the distance between the center line and the relative movement path of the magnetoresistive element gradually increases from the intersection toward the starting point of relative movement of the magnetoresistive element and the end point of relative movement. Opposed to spread in the width direction,
With the relative movement of the magnetoresistive effect element, the penetration direction of the external magnetic field from the plane direction parallel to the laminated interface penetrating into the laminated structure is rotationally displaced, and the electric resistance value of the magnetoresistive effect element changes. A movement sensor, wherein a movement position is detected.   The magnet is formed in such a shape that a center line length passing through a center of a width dimension is longer than a dimension in the width direction, and both side surfaces located on both sides of the width dimension extend in a direction parallel to the center line. The movement sensor according to claim 1.   The movement sensor according to claim 1, wherein the magnetoresistive effect element relatively moves linearly.   The movement sensor according to claim 1, wherein the magnetoresistive element is movably supported and the magnet is fixedly disposed.   In the magnetoresistive effect element, a laminated interface of the laminated structure is oriented in a direction orthogonal to a facing surface of the magnet facing the magnetoresistive effect element, and the facing surface of the magnet is a single magnetic pole surface. The movement sensor according to any one of claims 1 to 4. The first magnetic member and the second magnetic member are opposed to each other at an interval in the height direction, and the first magnetic member and the second magnetic member are viewed from directly above in the height direction. 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, The first magnetic member is formed in a shape in which the first center line and the second center line are separated from each other in the width direction from the intersection toward the one end direction and from the intersection toward the other end direction. And at least one of the second magnetic members is formed of the magnet,
In the space between the first magnetic member and the second magnetic member, the direction of the external magnetic field generated from the facing surface of one magnetic member toward the facing surface of the other magnetic member is the first magnetic member. A rotating magnetic field region that is gradually rotated and displaced from one end side to the other end side of the magnetic member and the second magnetic member is formed, and the magnetoresistive element has a layered interface of the layered structure in which the layered interface is magnetic. The member is directed in a direction orthogonal to a surface facing the magnetoresistive effect element of the member, and relatively moves so as to pass through the rotating magnetic field region from the one end side toward the other end side. The movement sensor according to any one of 1 to 4.   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 element is When viewed from directly above in the height direction, 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 is relatively moved linearly. The movement sensor according to claim 6.   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. Item 8. The movement sensor according to Item 6 or 7.

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