Magnetic sensor device, magnetic sensor system, and motion detection device

Abstract

To provide a magnetic sensor device capable of detecting both direction and intensity of a target magnetic field with a simple configuration.SOLUTION: A magnetic sensor device 2 comprises a magnetic sensor 1 and a processor 40. Each of first to third detection circuits 10a-10c of the magnetic sensor 1 includes MR elements 11, 12. Each of a plurality of laminate films 50 composing the MR elements 11, 12 includes a free layer 53c having a magnetic vortex structure and configured to move a centre 53c of the magnetic vortex structure according to a target magnetic field MF. The first to third detection circuits 10a-10c generate first to third detection signals S1-S3 which periodically change according to periodic change in a direction of the target magnetic field MF and the amplitude of which changes according to change in intensity of the target magnetic field MF. The processor 40 generates an angle detection value θs and an intensity detection value Va based on the first to third detection signals S1-S3.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a magnetic sensor device including a magnetoresistive effect element using a free layer with a magnetic vortex structure, and to a magnetic sensor system and a motion detection device each including the magnetic sensor device. [Background technology]

[0002] In recent years, angle sensors that generate angle detection values ​​corresponding to the angle of a detection target have been widely used in various applications, such as detecting the rotational position of a steering wheel or power steering motor in an automobile. An example of an angle sensor is an angle sensor using a magnetic detection element. An angle sensor system using a magnetic detection element generally includes a magnetic field generator that generates a detection target magnetic field whose direction rotates in conjunction with the rotation or linear movement of the target. The magnetic field generator is, for example, a magnet. The detection target angle corresponds to the angle between the direction of the detection target magnetic field at a reference position and a reference direction.

[0003] The magnetic detection element may be, for example, a spin-valve magnetoresistive element, which includes a pinned layer having a magnetization whose direction is fixed, a free layer having a magnetization whose direction can be changed depending on the direction of an applied magnetic field, and a gap layer disposed between the pinned layer and the free layer.

[0004] As an angle sensor using a spin-valve magnetoresistive effect element, as disclosed in Patent Document 1, there is known an angle sensor including two detection circuits each including a bridge circuit using a magnetoresistive effect element, the two detection circuits having output characteristics with different phases. In addition to the angle sensor, Patent Document 1 also discloses a magnetic field intensity sensor using a magnetoresistive effect element including a free layer with a magnetic vortex structure (also called a vortex structure). The angle sensor and the magnetic field intensity sensor are provided on the same substrate to constitute a single magnetic sensor. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2020 / 250489 Summary of the Invention [Problem to be solved by the invention]

[0006] An angle sensor system may be required to detect both the rotation and linear movement of an object. In such cases, it is conceivable to use a magnetic sensor such as that disclosed in Patent Document 1 to detect both the direction and strength of the magnetic field to be detected. However, the magnetic sensor disclosed in Patent Document 1 has a problem in that it is difficult to miniaturize the magnetic sensor because the angle sensor and the magnetic field strength sensor are provided separately.

[0007] The present invention has been made in consideration of such problems, and its purpose is to provide a magnetic sensor device that is capable of detecting both the direction and strength of a target magnetic field with a simple configuration, and a magnetic sensor system and a motion detection device that each include this magnetic sensor device. [Means for solving the problem]

[0008] The magnetic sensor device of the present invention includes a magnetic sensor configured to detect a target magnetic field and a processor. The magnetic sensor includes multiple detection circuits, each including a magnetoresistive element. The magnetoresistive element includes a magnetization fixed layer having a magnetization with a fixed direction and a free layer having a magnetic vortex structure and configured so that the center of the magnetic vortex structure moves in response to the target magnetic field. The multiple detection circuits are configured to generate multiple detection signals, each of which changes periodically in response to periodic changes in the direction of the target magnetic field and whose amplitude changes in response to changes in the strength of the target magnetic field. The processor is configured to generate, based on the multiple detection signals, an angle detection value corresponding to the angle that the direction of the target magnetic field makes with respect to a reference direction and an intensity detection value corresponding to the strength of the target magnetic field.

[0009] A magnetic sensor system of the present invention comprises the magnetic sensor device of the present invention and a magnetic field generator configured to generate a target magnetic field.

[0010] The motion detection device of the present invention comprises a component configured to be able to rotate around a reference axis and move in a direction parallel to the reference axis, the magnetic sensor device of the present invention, and a magnetic field generator configured to generate a target magnetic field and to operate in conjunction with the component. [Effects of the Invention]

[0011] In the magnetic sensor device of the present invention, each of the plurality of detection circuits includes a magnetoresistive element, and the magnetoresistive element includes a free layer having a magnetic vortex structure and configured such that the center of the magnetic vortex structure moves in response to a target magnetic field. The processor is configured to generate an angle detection value and an intensity detection value based on a plurality of detection signals generated by the plurality of detection circuits of the magnetic sensor. This makes it possible to detect both the direction and intensity of a target magnetic field with a simple configuration. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a perspective view showing a magnetic sensor system according to a first embodiment of the present invention. [Figure 2] FIG. 1 is a plan view showing a magnetic sensor system according to a first embodiment of the present invention. [Figure 3] FIG. 2 is an explanatory diagram for explaining a target magnetic field in the first embodiment of the present invention. [Figure 4] 1 is a circuit diagram showing a configuration of a magnetic sensor device according to a first embodiment of the present invention. [Figure 5] 1 is a perspective view showing a part of a magnetoresistive effect element according to a first embodiment of the present invention. [Figure 6] 1 is a perspective view showing a laminated film of a magnetoresistive effect element according to a first embodiment of the present invention. [Figure 7]1 is a plan view showing a free layer of a laminated film of a magnetoresistive effect element according to a first embodiment of the present invention. [Figure 8] 2 is a plan view showing a free layer when a target magnetic field is applied to the magnetoresistive element according to the first embodiment of the present invention. FIG. [Figure 9] 2 is a plan view showing a free layer when a target magnetic field is applied to the magnetoresistive element according to the first embodiment of the present invention. FIG. [Figure 10] FIG. 3 is a characteristic diagram showing the relationship between the intensity of a magnetic field component and the magnitude of magnetization of the entire free layer in the first embodiment of the present invention. [Figure 11] FIG. 3 is a waveform diagram showing waveforms of first to third detection signals of a first example in the first embodiment of the present invention. [Figure 12] FIG. 3 is a waveform diagram showing waveforms of first and second angle calculation signals of a first example in the first embodiment of the present invention. [Figure 13] FIG. 4 is a characteristic diagram showing a first example of detected intensity values ​​in the first embodiment of the present invention. [Figure 14] FIG. 4 is a waveform diagram showing waveforms of first to third detection signals in a second example according to the first embodiment of the present invention. [Figure 15] FIG. 10 is a waveform diagram showing waveforms of first and second angle calculation signals in a second example according to the first embodiment of the present invention. [Figure 16] FIG. 10 is a characteristic diagram showing a second example of detected intensity values ​​in the first embodiment of the present invention. [Figure 17] FIG. 10 is a perspective view showing a magnetic sensor system according to a second embodiment of the present invention. [Figure 18] FIG. 10 is a circuit diagram showing a configuration of a magnetic sensor device according to a third embodiment of the present invention. [Figure 19] FIG. 10 is a circuit diagram showing a configuration of a magnetic sensor device according to a fourth embodiment of the present invention. [Figure 20] FIG. 10 is a perspective view showing a motion detection device according to a fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013] [First embodiment] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, the configuration of a magnetic sensor system according to a first embodiment of the present invention will be described with reference to Figs. 1 and 2. Fig. 1 is a perspective view showing a magnetic sensor system 100 according to this embodiment. Fig. 2 is a plan view showing the magnetic sensor system 100 according to this embodiment. The magnetic sensor system 100 according to this embodiment is a magnetic angle sensor system, and includes a magnetic sensor 1 and a magnetic field generator 5.

[0014] The magnetic field generator 5 generates a magnetic field of the detection target related to the angle of the detection target. Hereinafter, the magnetic field of the detection target of the magnetic sensor 1 will be referred to as the target magnetic field MF. The magnetic field generator 5 in this embodiment is a cylindrical magnet. The magnetic field generator 5 has a north pole and a south pole arranged symmetrically about an imaginary plane including the central axis of the cylinder. The magnetic field generator 5 is configured to rotate in a direction D1 around the central axis of the cylinder. As a result, the direction of the target magnetic field MF rotates about a reference axis C including the central axis of the cylinder. The magnetic field generator 5 is further configured to move in a direction D2 parallel to the reference axis C.

[0015] Here, the angle to be detected is called the target angle and is represented by the symbol .theta.. The target angle .theta. in this embodiment is an angle corresponding to the rotation angle .theta.M of the magnetic field generator 5.

[0016] FIG. 3 is an explanatory diagram for explaining the target magnetic field MF. In FIG. 3, the symbol P indicates a reference plane, which is a virtual plane perpendicular to the reference axis C. Within this reference plane P, the direction of the target magnetic field MF rotates around a reference position PR, which is a position on the reference axis C. A reference direction DR is located within the reference plane P and intersects with the reference position PR. In the following description, the direction of the target magnetic field MF refers to a direction located within the reference plane P. The target angle θ is the angle that the direction of the target magnetic field MF makes with respect to the reference direction DR. For convenience, in FIG. 3, the angle that the direction of the target magnetic field MF makes with respect to the reference direction DR is represented by the symbol θ.

[0017] The direction of the target magnetic field MF is assumed to rotate counterclockwise in Fig. 3. The target angle θ is expressed as a positive value when viewed counterclockwise from the reference direction DR, and as a negative value when viewed clockwise from the reference direction DR.

[0018] The magnetic sensor 1 is configured to detect a target magnetic field MF and generate at least one detection signal corresponding to a target angle θ. In this embodiment, particularly, the magnetic sensor 1 is configured to detect the target magnetic field MF at each of a plurality of specific positions each spaced apart from the reference axis C.

[0019] The magnetic sensor 1 includes a first detection circuit 10a, a second detection circuit 10b, and a third detection circuit 10c. The first to third detection circuits 10a to 10c are arranged to face one end face of the magnetic field generator 5, i.e., the cylindrical magnet.

[0020] The first to third detection circuits 10a to 10c may each be in the form of a chip, or may be in the form of a package sealed with sealing resin. When the first to third detection circuits 10a to 10c are each in the form of a chip, the magnetic sensor 1 may be in the form of a single package in which the first to third detection circuits 10a to 10c are sealed with sealing resin.

[0021] The first detection circuit 10a is configured to detect the target magnetic field MF at a first position P1 away from the reference axis C and generate a first detection signal S1 that changes periodically in response to the periodic changes in the target magnetic field MF and whose amplitude changes in response to changes in the intensity of the target magnetic field MF. The second detection circuit 10b is configured to detect the target magnetic field MF at a second position P2 away from the reference axis C and generate a second detection signal S2 that changes periodically in response to the periodic changes in the target magnetic field MF and whose amplitude changes in response to changes in the intensity of the target magnetic field MF. The third detection circuit 10c is configured to detect the target magnetic field MF at a third position P3 away from the reference axis C and generate a third detection signal S3 that changes periodically in response to the periodic changes in the target magnetic field MF and whose amplitude changes in response to changes in the intensity of the target magnetic field MF. The direction and intensity of the target magnetic field MF at each of the first to third positions P1 to P3 are assumed to be the same as the direction and intensity of the target magnetic field MF at the reference position PR.

[0022] The first to third detection signals S1 to S3 each contain a periodic component that changes at an equal period. In this embodiment in particular, the periodic component changes periodically at a predetermined signal period so as to trace an ideal sinusoidal curve (including a sine waveform and a cosine waveform). When the magnetic field generator 5 rotates once, that is, when the rotation angle θM changes by 360°, the period of the periodic component changes by one period. The amplitude of the periodic component of the first detection signal S1, the amplitude of the periodic component of the second detection signal S2, and the amplitude of the periodic component of the third detection signal S3 may be equal to one another.

[0023] The first to third positions P1 to P3 will be described in detail below. Each of the first to third positions P1 to P3 may be a position on the reference plane P. Alternatively, at least one of the first to third positions P1 to P3 may be located away from the reference plane P. In the following description, the first to third positions P1 to P3 are assumed to be located on the reference plane P. The first to third positions P1 to P3 may also be located on an imaginary circle centered at the reference position PR.

[0024] 2, the second position P2 is a position rotated from the first position P1 by an angle θ1 in the axial direction around the reference axis C. The third position P3 is a position rotated from the first position P1 by an angle θ2 in the axial direction around the reference axis C.

[0025] Here, the period of the periodic component is assumed to be 360° electrical angle. Angle θ1 corresponds to 120° electrical angle. Angle θ2 corresponds to 240° electrical angle. In this embodiment in particular, an angle equivalent to 120° electrical angle is also physically 120°, and an angle equivalent to 240° electrical angle is also physically 240°.

[0026] Here, the U direction, V direction, W direction, and Z direction are defined as shown in FIGS. 1 to 3. In this embodiment, the Z direction is parallel to the reference axis C shown in FIG. 1 and extends from bottom to top in FIG. 1. In FIGS. 2 and 3, the Z direction is represented as a direction extending from the back to the front in FIGS. 2 and 3. The U direction is a direction perpendicular to the Z direction and extending from the reference axis C toward a first position P1. The V direction is a direction perpendicular to the Z direction and extending from the reference axis C toward a second position P2. The W direction is a direction perpendicular to the Z direction and extending from the reference axis C toward a third position P3. In this embodiment, the V direction is a direction rotated 120° counterclockwise from the U direction in FIGS. 2 and 3. The W direction is a direction rotated 120° counterclockwise from the V direction in FIGS. 2 and 3 and also rotated 120° clockwise from the U direction in FIGS. 2 and 3. In addition, the direction opposite to the U direction is the -U direction, the direction opposite to the V direction is the -V direction, the direction opposite to the W direction is the -W direction, and the direction opposite to the Z direction is the -Z direction. Hereinafter, the coordinate system based on the reference axis C will be referred to as the reference coordinate system.

[0027] Hereinafter, in the reference coordinate system and the Cartesian coordinate system described later, a position at the end of the Z direction relative to the reference position will be referred to as "above," and a position on the opposite side of "above" relative to the reference position will be referred to as "below." In addition, in this embodiment, the reference direction DR is the U direction.

[0028] The magnetic sensor 1 further includes a support 7 that supports the first to third detection circuits 10a to 10c. The support 7 is disposed at a predetermined distance from the magnetic field generator 5 in a direction parallel to the reference axis C. The support 7 has an upper surface 7a facing the magnetic field generator 5. The upper surface 7a may be perpendicular to the reference axis C, i.e., the Z direction. In this case, the reference plane P may be the upper surface 7a or a plane parallel to the upper surface 7a. In the example shown in FIG. 2, the first to third detection circuits 10a to 10c are disposed on the upper surface 7a of the support 7.

[0029] The configuration of the magnetic sensor system 100 according to this embodiment is not limited to the example shown in Fig. 1. The configuration of the magnetic sensor system 100 according to this embodiment may be any configuration in which the relative positional relationship between the magnetic field generator 5 and the magnetic sensor 1 changes so that the direction of the target magnetic field MF at the reference position PR rotates as seen from the magnetic sensor 1. For example, in the magnetic field generator 5 and the magnetic sensor 1 arranged as shown in Fig. 1, the magnetic field generator 5 may be fixed and the magnetic sensor 1 may rotate in the direction D1 around the axis, or the magnetic field generator 5 and the magnetic sensor 1 may rotate in opposite directions around the axis D1, or the magnetic field generator 5 and the magnetic sensor 1 may rotate in the same direction around the axis D1 at different angular velocities.

[0030] Furthermore, the magnetic sensor system 100 according to this embodiment may be configured such that the relative positional relationship between the magnetic field generator 5 and the magnetic sensor 1 changes so that the intensity of the target magnetic field MF at the reference position PR changes. For example, in the magnetic field generator 5 and the magnetic sensor 1 arranged as shown in Fig. 1, the magnetic field generator 5 may be fixed and the magnetic sensor 1 may move in direction D2, or the magnetic field generator 5 and the magnetic sensor 1 may move in opposite directions in direction D2, or the magnetic field generator 5 and the magnetic sensor 1 may move in the same direction in direction D2 by different distances. Note that the reference position PR moves as the magnetic sensor 1 moves.

[0031] Next, the configuration of the magnetic sensor 1 will be described in detail with reference to Fig. 4. Fig. 4 is a circuit diagram showing the configuration of the magnetic sensor device according to this embodiment.

[0032] The magnetic sensor device 2 according to this embodiment includes a magnetic sensor 1 and a processor 40. The processor 40 is configured to generate, based on the first to third detection signals S1 to S3, an angle detection value θs corresponding to the angle that the direction of the target magnetic field MF makes with respect to a reference direction DR, i.e., a target angle θ, and an intensity detection value Va corresponding to the intensity of the target magnetic field MF at a predetermined position. The predetermined position may be a reference position PR.

[0033] The processor 40 can be realized by, for example, an application specific integrated circuit (ASIC) or a microcomputer. The processor 40 may be included in the support 7 shown in FIG. 2, or may be located at a position remote from the first to third detection circuits 10a to 10c and the magnetic field generator 5.

[0034] The first detection circuit 10a includes a first magnetic detection element. The characteristics of the first magnetic detection element change depending on the target magnetic field MF at the first position P1, i.e., the target magnetic field MF applied to the first detection circuit 10a. In this embodiment, the first detection circuit 10a includes two magnetoresistive effect elements (hereinafter referred to as MR elements) 11a and 12a as the first magnetic detection elements. The first detection circuit 10a further includes a power supply port V1, a ground port G1, and an output port E1. In terms of the circuit configuration, the MR element 11a is provided between the power supply port V1 and the output port E1. In terms of the circuit configuration, the MR element 12a is provided between the ground port G1 and the output port E1. A voltage or current of a predetermined magnitude is applied to the power supply port V1. The ground port G1 is connected to ground. Note that in this application, the expression "in terms of the circuit configuration" refers to the arrangement on a circuit diagram, not the arrangement in a physical configuration.

[0035] The second detection circuit 10b includes a second magnetic detection element. The characteristics of the second magnetic detection element change depending on the target magnetic field MF at the second position P2, i.e., the target magnetic field MF applied to the second detection circuit 10b. In this embodiment, the second detection circuit 10b includes two MR elements 11b and 12b as the second magnetic detection element. The second detection circuit 10b further includes a power supply port V2, a ground port G2, and an output port E2. In terms of the circuit configuration, the MR element 11b is provided between the power supply port V2 and the output port E2. In terms of the circuit configuration, the MR element 12b is provided between the ground port G2 and the output port E2. A voltage or current of a predetermined magnitude is applied to the power supply port V2. The ground port G2 is connected to ground.

[0036] The third detection circuit 10c includes a third magnetic detection element. The characteristics of the third magnetic detection element change depending on the target magnetic field MF at the third position P3, i.e., the target magnetic field MF applied to the third detection circuit 10c. In this embodiment, the third detection circuit 10c particularly includes two MR elements 11c and 12c as the third magnetic detection element. The third detection circuit 10c further includes a power supply port V3, a ground port G3, and an output port E3. In terms of the circuit configuration, the MR element 11c is provided between the power supply port V3 and the output port E3. In terms of the circuit configuration, the MR element 12c is provided between the ground port G3 and the output port E3. A predetermined voltage or current is applied to the power supply port V3. The ground port G3 is connected to ground.

[0037] The magnetic sensor device 2 further includes differential detectors 31, 32, and 33. The differential detector 31 outputs a signal corresponding to the potential difference between the output ports E1 and E2 as a first signal Sa. The differential detector 32 outputs a signal corresponding to the potential difference between the output ports E2 and E3 as a second signal Sb. The differential detector 33 outputs a signal corresponding to the potential difference between the output ports E3 and E1 as a third signal Sc.

[0038] The first to third signals Sa to Sc may be generated by digital signal processing. That is, each of the difference detectors 31, 32, and 33 may be configured by a differential analog-to-digital converter such as an ASIC or a microcomputer. In this case, the difference detectors 31, 32, and 33 may be integrated with the processor 40. Alternatively, the first to third signals Sa to Sc may be generated by analog signal processing. That is, each of the difference detectors 31, 32, and 33 may be configured by a circuit using an operational amplifier. In this case, the difference detectors 31, 32, and 33 may be integrated with the processor 40 or may be separate from the processor 40.

[0039] Here, any one of the first to third detection circuits 10a to 10c will be represented by the reference numeral 10. Furthermore, among the MR elements included in the detection circuit 10, the MR elements corresponding to the MR elements 11a, 11b, and 11c will be represented by the reference numeral 11, and the MR elements corresponding to the MR elements 12a, 12b, and 12c will be represented by the reference numeral 12.

[0040] The configuration of the MR elements 11 and 12 will be described in detail below with reference to Fig. 5. Fig. 5 is a perspective view showing a part of the MR elements 11 and 12.

[0041] Each of the MR elements 11 and 12 includes at least one laminated film. In particular, in this embodiment, each of the MR elements 11 and 12 includes a plurality of laminated films 50 connected in series as at least one laminated film. Each of the MR elements 11 and 12 further includes a plurality of lower electrodes 61 and a plurality of upper electrodes 62. Each of the plurality of lower electrodes 61 has an elongated shape. A gap is formed between two lower electrodes 61 adjacent in the longitudinal direction of the lower electrodes 61. A laminated film 50 is disposed on the upper surface of each lower electrode 61 near both ends in the longitudinal direction of the lower electrode 61. Each of the plurality of upper electrodes 62 has an elongated shape and is disposed on two lower electrodes 61 adjacent in the longitudinal direction of the lower electrode 61 to electrically connect the two adjacent laminated films 50.

[0042] Although not shown, one stacked film 50 located at an end of a row of a plurality of stacked films 50 is connected to another stacked film 50 located at an end of another row of a plurality of adjacent stacked films 50 in a direction intersecting the longitudinal direction of the lower electrode 61. These two stacked films 50 are connected to each other by an electrode not shown. The electrode not shown may be an electrode connecting the lower surfaces or upper surfaces of the two stacked films 50 to each other.

[0043] The magnetic sensor 1 further includes a substrate (not shown) and an insulating layer (not shown). The detection circuit 10 is disposed on the substrate and is integrated by the insulating layer.

[0044] The magnetic sensor 1 further includes a plurality of electrode pads (not shown). The plurality of electrode pads include a power supply port electrode pad corresponding to the power supply port V1, V2, or V3, a ground port electrode pad corresponding to the ground port G1, G2, or G3, and an output port electrode pad corresponding to the output port E1, E2, or E3. These electrode pads and the MR elements 11 and 12 are electrically connected.

[0045] Next, the configuration of the laminated film 50 of each of the MR elements 11 and 12 will be described with reference to Fig. 6 and Fig. 7. Fig. 6 is a perspective view showing the laminated film of the MR elements 11 and 12. Fig. 7 is a plan view showing the free layer of the laminated film of the MR elements 11 and 12.

[0046] Here, the X, Y, and Z directions are defined as shown in FIGS. 6 and 7. The X, Y, and Z directions are perpendicular to one another. The direction opposite the X direction is defined as the -X direction, and the direction opposite the Y direction is defined as the -Y direction. The Cartesian coordinate system defined by the X, Y, and Z directions shown in FIGS. 6 and 7 is a coordinate system defined with the detection circuit 10 as the reference. The Z direction of this Cartesian coordinate system coincides with the Z direction of the reference coordinate system defined by the reference axis C shown in FIG. 1.

[0047] The stacked film 50 includes a magnetization fixed layer 51 having a magnetization 51m with a fixed direction, a free layer 53, and a gap layer 52 disposed between the magnetization fixed layer 51 and the free layer 53. The material and shape of the free layer 53 are selected so as to have a magnetic vortex structure (also called a vortex structure). The gap layer 52 is a tunnel barrier layer or a non-magnetic conductive layer.

[0048] The free layer 53 has a cylindrical or nearly cylindrical shape. The free layer 53 has a vortex magnetization 53m centered around a center 53c of the magnetic vortex structure. When no magnetic field is applied to the stacked film 50, the center 53c of the magnetic vortex structure coincides with or nearly coincides with the axis of the cylinder. The center 53c of the magnetic vortex structure moves in response to the target magnetic field MF. In the examples shown in FIGS. 6 and 7, the entire stacked film 50 has a cylindrical shape.

[0049] The center 53c of the magnetic vortex structure moves when a component of the target magnetic field MF perpendicular to the Z direction is applied to the free layer 53. It is preferable that the free layer 53 does not saturate within the range of change in the intensity of this component.

[0050] The magnetization 51m of the magnetization fixed layer 51 includes a component parallel to the X direction. The magnetization 51m of the magnetization fixed layer 51 in the MR element 11 and the magnetization 51m of the magnetization fixed layer 51 in the MR element 12 include components in opposite directions.

[0051] When the magnetization 51m of the magnetization fixed layer 51 includes a component in a specific direction, the component in the specific direction may be the main component of the magnetization 51m of the magnetization fixed layer 51. Alternatively, the magnetization 51m of the magnetization fixed layer 51 may not include a component in a direction perpendicular to the specific direction. In this embodiment, when the magnetization 51m of the magnetization fixed layer 51 includes a component in a specific direction, the direction of the magnetization 51m of the magnetization fixed layer 51 becomes a specific direction or approximately a specific direction.

[0052] The laminated film 50 may further include an antiferromagnetic layer. The antiferromagnetic layer is made of an antiferromagnetic material and generates exchange coupling with the magnetization fixed layer 51 to fix the magnetization of the magnetization fixed layer 51. 51m Alternatively, the magnetization fixed layer 51 may be a so-called self-pinned type fixed layer (synthetic ferri-pinned layer, SFP layer). The self-pinned type fixed layer has a synthetic ferri-structure in which a ferromagnetic layer, a non-magnetic intermediate layer, and a ferromagnetic layer are stacked, and the two ferromagnetic layers are antiferromagnetically coupled.

[0053] Here, the resistance value of the laminated film 50 will be described taking as an example the case where the direction of the magnetization 51m of the magnetization fixed layer 51 is the −X direction. Figures 8 and 9 show the free layer 53 when a magnetic field component MFx in a direction parallel to the X direction of the target magnetic field MF is applied to the free layer 53.

[0054] 8 shows the free layer 53 when the direction of the magnetic field component MFx is the X direction. In this case, the magnetic field component MFx moves the center 53c of the magnetic vortex structure, and the amount of magnetization 53m oriented in the X direction becomes greater than the amount of magnetization 53m oriented in the −X direction. In this case, the resistance value of the stacked film 50 increases.

[0055] 9 shows the free layer 53 when the direction of the magnetic field component MFx is the −X direction. In this case, the magnetic field component MFx moves the center 53c of the magnetic vortex structure, and the amount of magnetization 53m oriented in the −X direction becomes greater than the amount of magnetization 53m oriented in the X direction. In this case, the resistance value of the stacked film 50 decreases.

[0056] The amount of change in the resistance value of the laminated film 50 depends on the strength of the magnetic field component MFx. When the direction of the magnetic field component MFx is the X direction, as the strength of the magnetic field component MFx increases, the amount of magnetization 53m oriented in the X direction increases. The resistance value of the laminated film 50 increases as the amount of magnetization 53m oriented in the X direction increases. Also, when the direction of the magnetic field component MFx is the −X direction, as the strength of the magnetic field component MFx increases, the amount of magnetization 53m oriented in the −X direction increases. The resistance value of the laminated film 50 decreases as the amount of magnetization 53m oriented in the −X direction increases. As the strength of the magnetic field component MFx increases, the resistance value of the laminated film 50 changes in a direction in which its increase or decrease increases. As the strength of the magnetic field component MFx decreases, the resistance value of the laminated film 50 changes in a direction in which its increase or decrease decreases.

[0057] The amount of change in the resistance value of each of the MR elements 11 and 12 depends on the strength of the magnetic field component MFx that each of the multiple laminated films 50 receives. As the strength of the magnetic field component MFx increases, the resistance value of each of the MR elements 11 and 12 changes in a direction in which the increase or decrease in the resistance value increases. As the strength of the magnetic field component MFx decreases, the resistance value of each of the MR elements 11 and 12 changes in a direction in which the increase or decrease in the resistance value decreases. The strength of the magnetic field component MFx depends on the strength of the component of the target magnetic field MF applied to each of the MR elements 11 and 12 in a direction parallel to the X direction.

[0058] As described above, the magnetization of the magnetization fixed layer 51 in the MR element 11 and the magnetization of the magnetization fixed layer 51 in the MR element 12 contain components in opposite directions. Therefore, when the direction and strength of the target magnetic field MF applied to the detection circuit 10 change, the resistance values ​​of the MR elements 11 and 12 change such that the resistance value of the MR element 11 increases while the resistance value of the MR element 12 decreases, or the resistance value of the MR element 11 decreases while the resistance value of the MR element 12 increases. This causes a change in the potential at the connection point between the MR elements 11 and 12.

[0059] The first detection circuit 10a generates a signal corresponding to the potential of output port E1 connected to the connection point between MR element 11a and MR element 12a as a first detection signal S1. The second detection circuit 10b generates a signal corresponding to the potential of output port E2 connected to the connection point between MR element 11b and MR element 12b as a second detection signal S2. The third detection circuit 10c generates a signal corresponding to the potential of output port E3 connected to the connection point between MR element 11c and MR element 12c as a third detection signal S3.

[0060] Here, the relationship between the strength of the magnetic field component MFx and the magnitude of magnetization of the entire free layer 53 will be described with reference to FIG. 10. FIG. 10 is a characteristic diagram schematically showing the relationship between the strength of the magnetic field component MFx and the magnitude of magnetization of the entire free layer 53. In FIG. 10, the horizontal axis represents the strength Hx of the magnetic field component MFx, and the vertical axis represents the magnitude of magnetization Mx of the entire free layer 53. In FIG. 10, the strength Hx when the direction of the magnetic field component MFx is the X direction is represented by a positive value, and the strength Hx when the direction of the magnetic field component MFx is the −X direction is represented by a negative value. When the direction of the magnetic field component MFx is the X direction, as the amount of magnetization 53m oriented in the X direction increases, the magnitude of magnetization Mx of the entire free layer 53 increases. When the direction of the magnetic field component MFx is the −X direction, as the amount of magnetization 53m oriented in the −X direction increases, the magnitude of magnetization Mx of the entire free layer 53 decreases.

[0061] First, we will explain the case where the intensity Hx is increased from 0. As the intensity Hx is gradually increased from 0, the magnitude of magnetization Mx gradually increases. When the intensity Hx reaches a value Hx1 or greater, the magnitude of magnetization Mx becomes constant and the free layer 53 is saturated.

[0062] Next, a description will be given of the case where the intensity Hx is decreased from 0. When the intensity Hx is gradually decreased from 0, the magnitude of magnetization Mx also gradually decreases. When the intensity Hx becomes equal to or less than a value Hx2, the magnitude of magnetization Mx becomes constant and the free layer 53 is saturated.

[0063] 10, within a predetermined range where the intensity Hx is greater than value Hx2 and less than value Hx1, the magnitude of magnetization Mx changes linearly with respect to the change in intensity Hx. Note that "changing linearly" means that the magnitude of magnetization Mx changes linearly or almost linearly with respect to the change in intensity Hx in a characteristic diagram showing the relationship between the intensity Hx and the magnitude of magnetization Mx.

[0064] In this embodiment, it is preferable that the free layer 53 does not saturate within the range of change in the intensity Hx, and it is more preferable that the magnitude of magnetization Mx changes linearly with change in the intensity Hx.

[0065] When the intensity Hx is reduced from a value Hx3 greater than Hx1 after the free layer 53 has saturated and the intensity Hx is reduced from this value Hx3, the magnitude of magnetization Mx remains almost constant until the intensity Hx reaches a value Hx4 less than Hx1. When the intensity Hx is reduced below Hx4, the magnitude of magnetization Mx changes linearly with the intensity Hx, as in the case where the intensity Hx is varied within a predetermined range greater than Hx2 and less than Hx1.

[0066] Similarly, when the intensity Hx becomes smaller than the value Hx2 and the free layer 53 becomes saturated, if the intensity Hx is decreased from a value Hx5 smaller than the value Hx2, the magnitude of magnetization Mx changes little until it reaches a value Hx6 larger than the value Hx2. When the intensity Hx becomes larger than the value Hx6, the magnitude of magnetization Mx changes linearly with the change in the intensity Hx, just as when the intensity Hx is changed within a predetermined range larger than the value Hx2 and smaller than the value Hx1.

[0067] Next, the relationship between the reference coordinate system shown in FIGS. 1 to 4 and the orthogonal coordinate system shown in FIGS. 6 to 9 will be described. The orthogonal coordinate systems shown in FIGS. 6 to 9 are defined for the first to third detection circuits 10a to 10c. In the first detection circuit 10a, the X direction in the orthogonal coordinate system coincides with the U direction in the reference coordinate system, and the Y direction in the orthogonal coordinate system coincides with a direction rotated by 90° from the U direction in the reference coordinate system toward the V direction in the reference coordinate system. In the second detection circuit 10b, the X direction in the orthogonal coordinate system coincides with the V direction in the reference coordinate system, and the Y direction in the orthogonal coordinate system coincides with a direction rotated by 90° from the V direction in the reference coordinate system toward the W direction in the reference coordinate system. In the third detection circuit 10c, the X direction in the orthogonal coordinate system coincides with the W direction in the reference coordinate system, and the Y direction in the orthogonal coordinate system coincides with a direction rotated by 90° from the W direction in the reference coordinate system toward the U direction in the reference coordinate system.

[0068] 4, one laminated film 50 is schematically shown as a diagram representing each of the MR elements 11a, 11b, 11c, 12a, 12b, and 12c. Arrows drawn in the laminated film 50 indicate the direction of the magnetization 51m of the magnetization fixed layer 51 of that laminated film 50. In the first detection circuit 10a, the magnetization 51m of the magnetization fixed layer 51 in the MR element 11a includes a component in the −U direction, and the magnetization 51m of the magnetization fixed layer 51 in the MR element 12a includes a component in the U direction. In the second detection circuit 10b, the magnetization 51m of the magnetization fixed layer 51 in the MR element 11b includes a component in the −V direction, and the magnetization 51m of the magnetization fixed layer 51 in the MR element 12b includes a component in the V direction. In the third detection circuit 10c, the magnetization 51m of the magnetization fixed layer 51 in the MR element 11c includes a component in the −W direction, and the magnetization 51m of the magnetization fixed layer 51 in the MR element 12c includes a component in the W direction.

[0069] Next, a method for generating the detected angle value θs and the detected intensity value Va will be described with reference to FIG. 4. The following description includes a description of the operation of the processor 40. In this embodiment, the phase difference between the periodic component of the first detection signal S1 and the periodic component of the second detection signal S2 and the phase difference between the periodic component of the second detection signal S2 and the periodic component of the third detection signal S3 are both ⅓ of the period of the periodic component. The phase of the periodic component of the second detection signal S2 differs from the phase of the periodic component of the first detection signal S1 by ⅓ of the period of the periodic component, i.e., 120°. The phase of the periodic component of the third detection signal S3 differs from the phase of the periodic component of the second detection signal S2 by ⅓ of the period of the periodic component, i.e., 120°. Furthermore, the phase difference between the periodic component of the first detection signal S1 and the periodic component of the third detection signal S3 is ⅔ of the period of the periodic component. The phase of the periodic component of the third detection signal S3 differs from the phase of the periodic component of the first detection signal S1 by ⅔ of the period of the periodic component, that is, 240°.

[0070] The first signal Sa output from the differential detector 31, the second signal Sb output from the differential detector 32, and the third signal Sc output from the differential detector 33 are expressed by the following equations (1), (2), and (3), respectively.

[0071] Sa = S1 - S2 ... (1) Sb = S2 - S3 … (2) Sc = S3 - S1 ... (3)

[0072] The first signal Sa corresponds to the difference between the first detection signal S1 and the second detection signal S2. The second signal Sb corresponds to the difference between the second detection signal S2 and the third detection signal S3. The third signal Sc corresponds to the difference between the third detection signal S3 and the first detection signal S1. The processor 40 is configured to generate an angle detection value θs using the first to third signals Sa to Sc. The processor 40 calculates θs within the range of 0° or more and less than 360°, for example, using the following equation (4). Note that "atan" represents arc tangent.

[0073]

number

[0074] Here, the signal obtained by multiplying the first signal Sa by the square root of 3 is called the first angle calculation signal Sd1, and the signal obtained by subtracting the second signal Sb from the third signal Sc is called the second angle calculation signal Sd2. As can be seen from equation (4), the detected angle value θs can be calculated by finding the arctangent of the ratio of the first angle calculation signal Sd1 to the second angle calculation signal Sd2.

[0075] The processor 40 is also configured to generate the intensity detection value Va by using the sum of squares of the first to third signals Sa to Sc. The processor 40 may use the sum of squares of the first to third signals Sa to Sc as the intensity detection value Va. Alternatively, the processor 40 may calculate Va using the following equation (5):

[0076]

number

[0077] The processor 40 may be configured to detect the rotational position of the magnetic field generator 5 using the detected angle value θs, and to detect the position of the magnetic field generator 5 in a direction D2 parallel to the reference axis C using the detected intensity value Va. The rotational position of the magnetic field generator 5 can be calculated, for example, using the detected angle value θs and the number of rotations of the magnetic field generator 5 counted from the detected angle value θs. The position of the magnetic field generator 5 in the direction D2 parallel to the reference axis C can be calculated, for example, by multiplying the detected intensity value Va by a predetermined coefficient.

[0078] Next, a brief description will be given of a method for manufacturing the magnetic sensor 1 according to this embodiment. The method for manufacturing the magnetic sensor 1 includes a step of forming the detection circuit 10. The step of forming the detection circuit 10 includes a step of forming MR elements 11 and 12. The step of forming the MR elements 11 and 12 includes a step of forming a plurality of stacked films 50.

[0079] In the process of forming the plurality of stacked films 50, first, a plurality of initial stacked films are formed, which will later become the plurality of stacked films 50. Each of the plurality of initial stacked films includes at least an initial magnetization fixed layer, which will later become the magnetization fixed layer 51, a free layer 53, and a gap layer 52.

[0080] Next, the magnetization direction of the initial magnetization fixed layer is fixed in the predetermined direction using laser light and an external magnetic field in a predetermined direction. For example, the initial stacked films that will later become the stacked films 50 of the MR element 11 are irradiated with laser light while applying an external magnetic field in the −X direction. When the irradiation of the laser light is completed, the magnetization direction of the initial magnetization fixed layer is fixed in the −X direction. As a result, the initial magnetization fixed layer becomes the magnetization fixed layer 51, and the initial stacked films become the stacked films 50 of the MR element 11.

[0081] Furthermore, in the other initial laminated films that will later become the laminated films 50 of the MR element 12, the direction of the external magnetic field is set to the X direction, so that the magnetization direction of each initial magnetization pinned layer of the other initial laminated films can be fixed in the X direction. In this way, the laminated films 50 of the MR element 12 are formed.

[0082] Next, the operation and effects of the magnetic sensor device 2 and the magnetic sensor system 100 according to this embodiment will be described. In this embodiment, both the detected angle value θs and the detected intensity value Va can be generated based on the first to third detection signals S1 to S3. This can be achieved by using a free layer 53 having a magnetic vortex structure. As shown in FIG. 10 , within a predetermined range in which the intensity Hx of the magnetic field component MFx is greater than value Hx2 and less than value Hx1, the intensity Hx of the magnetic field component MFx can be uniquely determined from the magnitude Mx of the magnetization of the entire free layer 53. The magnitude Mx of the magnetization of the entire free layer 53 corresponds to the amount of magnetization 53m of the free layer 53 oriented in a specific direction, and the amount of magnetization 53m corresponds to the resistance value of the stacked film 50.

[0083] Furthermore, the resistance value of the laminated film 50 in the MR elements 11a and 12a corresponds to the first detection signal S1. The resistance value of the laminated film 50 in the MR elements 11b and 12b corresponds to the second detection signal S2. The resistance value of the laminated film 50 in the MR elements 11c and 12c corresponds to the third detection signal S3. Therefore, according to this embodiment, the intensity Hx of the magnetic field component MFx can be uniquely determined based on the first to third detection signals S1 to S3.

[0084] Furthermore, when the intensity Hx of the magnetic field component MFx varies periodically, the magnitude Mx of the magnetization of the entire free layer 53 varies periodically within a predetermined range where the intensity Hx of the magnetic field component MFx is greater than value Hx2 and less than value Hx1. Therefore, when the intensity Hx of the magnetic field component MFx varies periodically, the first to third detection signals S1 to S3 also vary periodically. Furthermore, in this embodiment, the phases of the periodic components of the first detection signal S1, the second detection signal S2, and the third detection signal S3 are different from each other. Therefore, according to this embodiment, the angle detection value θs can be generated based on the first to third detection signals S1 to S3.

[0085] Next, first and second examples of the first to third detection signals S1 to S3 and the intensity detection value Va in this embodiment will be described. First, the first example will be described. FIG. 11 is a waveform diagram showing the waveforms of the first to third detection signals S1 to S3 in the first example. In FIG. 11, the horizontal axis represents the rotation angle θM, and the vertical axis represents the values ​​of the first to third detection signals S1 to S3. Also, in FIG. 11, the curve labeled 71 represents the first detection signal S1, the curve labeled 72 represents the second detection signal S2, and the curve labeled 73 represents the third detection signal S3. FIG. 11 shows the first to third detection signals S1 to S3 when the magnetic flux density value corresponding to the target magnetic field MF is 20 mT.

[0086] FIG. 12 is a waveform diagram showing the waveforms of the first and second angle calculation signals Sd1 and Sd2 in the first example. In FIG. 12, the horizontal axis represents the rotation angle θM, and the vertical axis represents the values ​​of the first and second angle calculation signals Sd1 and Sd2. Also in FIG. 12, the curve labeled 74 represents the first angle calculation signal Sd1, and the curve labeled 75 represents the second angle calculation signal Sd2. FIG. 12 shows the first to third signals Sa to Sc generated using the first to third detection signals S1 to S3 shown in FIG. 11 and equations (1) to (3), and the first and second angle calculation signals Sd1 and Sd2 generated using these first to third signals Sa to Sc. As shown in FIG. 12, the phase difference between the first angle calculation signal Sd1 and the second angle calculation signal Sd2 is 90°. Therefore, as described above, the detected angle value θs can be generated by using the first and second angle calculation signals Sd1, Sd2 and equation (4).

[0087] FIG. 13 is a characteristic diagram showing the intensity detection value Va of the first example. In FIG. 13, the horizontal axis represents the rotation angle θM, and the vertical axis represents the value of the intensity detection value Va. FIG. 13 shows the intensity detection value Va generated using the first to third detection signals S1 to S3 shown in FIG. 11 and equation (4). As shown in FIG. 13, in an environment where the intensity of the target magnetic field MF is constant, the value of the intensity detection value Va is constant. The unit of the intensity detection value Va shown in FIG. 13 is mV. The processor 40 may multiply the intensity detection value Va shown in FIG. 13 by a predetermined coefficient so that the value of the intensity detection value Va becomes the value of the magnetic flux density corresponding to the target magnetic field MF.

[0088] Next, a second example will be described. FIG. 14 is a waveform diagram showing the waveforms of the first to third detection signals S1 to S3 of the second example. The horizontal and vertical axes in FIG. 14 are the same as those in FIG. 11. In FIG. 14, the curve labeled 81 indicates the first detection signal S1, the curve labeled 82 indicates the second detection signal S2, and the curve labeled 83 indicates the third detection signal S3. FIG. 14 shows the first to third detection signals S1 to S3 when the magnetic flux density value corresponding to the target magnetic field MF is 40 mT. As can be seen from FIGS. 11 and 14, the amplitude of each of the first to third detection signals S1 to S3 changes in accordance with changes in the strength of the target magnetic field MF.

[0089] FIG. 15 is a waveform diagram showing the waveforms of the first and second angle calculation signals Sd1 and Sd2 in the second example. The horizontal and vertical axes in FIG. 15 are the same as those in FIG. 12. In FIG. 15, the curve labeled 84 indicates the first angle calculation signal Sd1, and the curve labeled 85 indicates the second angle calculation signal Sd2. FIG. 15 shows the first to third signals Sa to Sc generated using the first to third detection signals S1 to S3 shown in FIG. 14 and equations (1) to (3), and the first and second angle calculation signals Sd1 and Sd2 generated using these first to third signals Sa to Sc. As shown in FIG. 15, in the second example, the amplitude of each of the first and second angle calculation signals Sd1 and Sd2 is larger than in the first example. 15, the phase difference between the first angle calculation signal Sd1 and the second angle calculation signal Sd2 is 90°. Therefore, similar to the first example, the detected angle value θs can be generated by using the first and second angle calculation signals Sd1 and Sd2 and equation (4).

[0090] Fig. 16 is a characteristic diagram showing the intensity detection value Va of the second example. The horizontal and vertical axes in Fig. 16 are the same as those in Fig. 13. Fig. 16 shows the intensity detection value Va generated using the first to third detection signals S1 to S3 shown in Fig. 14 and equation (4). As can be seen from Figs. 13 and 16, the value of the intensity detection value Va changes according to changes in the intensity of the target magnetic field MF.

[0091] [Second embodiment] Next, a configuration of a magnetic sensor system according to a second embodiment of the present invention will be described with reference to Fig. 17. Fig. 17 is a perspective view showing the magnetic sensor system according to this embodiment.

[0092] In this embodiment, the magnetic sensor 1 is configured to detect a target magnetic field MF at a reference position PR on a reference axis C. The first detection circuit 10a of the magnetic sensor 1 is configured to detect the target magnetic field MF at the reference position PR and generate a first detection signal S1. The second detection circuit 10b of the magnetic sensor 1 is configured to detect the target magnetic field MF at the reference position PR and generate a second detection signal S2. The third detection circuit 10c of the magnetic sensor 1 is configured to detect the target magnetic field MF at the reference position PR and generate a third detection signal S3.

[0093] Each of the first to third detection circuits 10a to 10c is disposed at a position where it can detect the target magnetic field MF at the reference position PR. For example, the first to third detection circuits 10a to 10c may all be disposed on the reference axis C. That is, the first to third detection circuits 10a to 10c may each be disposed at a position on the reference axis C. In this case, the first to third detection circuits 10a to 10c may be stacked in any order. Alternatively, the first to third detection circuits 10a to 10c may be disposed on the upper surface of a support perpendicular to the reference axis C, as long as the requirement of detecting the target magnetic field MF at the reference position PR is met.

[0094] The configuration of each of the first to third detection circuits 10a to 10c is the same as that of the first embodiment. In particular, the direction of the magnetization 51m of the magnetization fixed layer 51 in each of the MR elements 11a to 11c and 12a to 12c is the same as that described with reference to FIG. 4 in the first embodiment.

[0095] Other configurations, actions, and effects of this embodiment are the same as those of the first embodiment.

[0096] [Third embodiment] Next, a magnetic sensor device according to a third embodiment of the present invention will be described with reference to Fig. 18. Fig. 18 is a circuit diagram showing the configuration of the magnetic sensor device according to this embodiment.

[0097] The magnetic sensor device 2 according to this embodiment does not include the differential detectors 31, 32, and 33 of the first embodiment. Moreover, the magnetic sensor device 2 includes a magnetic sensor 101 instead of the magnetic sensor 1 of the first embodiment. The magnetic sensor 101 includes a first detection circuit 110a and a second detection circuit 110b. Like the first to third detection circuits 10a to 10c, the first and second detection circuits 110a and 110b may each be in the form of a chip or in the form of a package sealed with sealing resin.

[0098] The first detection circuit 110a is configured to detect the target magnetic field MF at a first position and generate a first detection signal S11 that changes periodically in response to the periodic changes in the target magnetic field MF and whose amplitude changes in response to changes in the intensity of the target magnetic field MF. The second detection circuit 110b is configured to detect the target magnetic field MF at a second position and generate a second detection signal S12 that changes periodically in response to the periodic changes in the target magnetic field MF and whose amplitude changes in response to changes in the intensity of the target magnetic field MF. The first and second positions may be positions away from the reference axis C (see FIG. 1), similar to the positions where the first to third detection circuits 10a to 10c are arranged in the first embodiment, or may be positions on the reference axis C (see FIG. 17), similar to the positions where the first to third detection circuits 10a to 10c are arranged in the second embodiment.

[0099] When the first and second positions are positions away from the reference axis C, the second position is a position rotated from the first position by a predetermined angle in the axial direction around the reference axis C. The predetermined angle corresponds to an odd multiple of 90° electrical angle. In this embodiment in particular, the angle corresponding to an odd multiple of 90° electrical angle is also physically an odd multiple of 90° electrical angle.

[0100] The first detection circuit 110a includes two MR elements 111a and 112a, a power supply port V11, a ground port G11, and an output port E11. The MR element 111a is provided between the power supply port V11 and the output port E11 in terms of the circuit configuration. The MR element 112a is provided between the ground port G11 and the output port E11 in terms of the circuit configuration. A voltage or current of a predetermined magnitude is applied to the power supply port V11. The ground port G11 is connected to ground.

[0101] The second detection circuit 110b includes two MR elements 111b and 112b, a power supply port V12, a ground port G12, and an output port E12. In terms of the circuit configuration, the MR element 111b is provided between the power supply port V12 and the output port E12. In terms of the circuit configuration, the MR element 112b is provided between the ground port G12 and the output port E12. A voltage or current of a predetermined magnitude is applied to the power supply port V12. The ground port G12 is connected to ground.

[0102] The configuration of the MR elements 111a and 111b is the same as the configuration of the MR element 11 in the first embodiment. The configuration of the MR elements 112a and 112b is the same as the configuration of the MR element 12 in the first embodiment.

[0103] Here, as shown in FIG. 18, the DR1 direction, the DR2 direction, and the Z direction are defined. The DR1 direction, the DR2 direction, and the Z direction are perpendicular to one another. The direction opposite to the DR1 direction is defined as the -DR1 direction, the direction opposite to the DR2 direction is defined as the -DR2 direction, and the direction opposite to the Z direction is defined as the -Z direction. The Cartesian coordinate system defined by the DR1 direction, the DR2 direction, and the Z direction shown in FIG. 18 is the reference coordinate system in this embodiment. The Z direction of this Cartesian coordinate system coincides with the Z direction of the reference coordinate system defined by the reference axis C shown in FIGS. 1, 2, and 17.

[0104] 18, one laminated film 50 is shown as a schematic diagram representing each of the MR elements 111a, 111b, 112a, and 112b. Arrows drawn in the laminated film 50 indicate the direction of the magnetization 51m of the magnetization fixed layer 51 of the laminated film 50. In the first detection circuit 110a, the magnetization 51m of the magnetization fixed layer 51 in the MR element 111a is -DR 2 The magnetization 51m of the magnetization fixed layer 51 in the MR element 112a includes a component in the DR direction. 2 In the second detection circuit 110b, the magnetization 51m of the magnetization fixed layer 51 in the MR element 111b includes a component in the DR1 direction, and the magnetization 51m of the magnetization fixed layer 51 in the MR element 112b includes a component in the -DR1 direction.

[0105] In this embodiment, the first detection circuit 110a and the second detection circuit 110b are configured with circuits having substantially the same configuration. The second detection circuit 110b corresponds to the first detection circuit 110a rotated by 90° around an axis (reference axis C) extending in a direction parallel to the Z direction.

[0106] The first detection circuit 110a generates a signal corresponding to the potential of the output port E11 connected to the connection point between the MR elements 111a and 112a as a first detection signal S11. The second detection circuit 110b generates a signal corresponding to the potential of the output port E12 connected to the connection point between the MR elements 111b and 112b as a second detection signal S12.

[0107] Next, a method for generating the detected angle value θs and the detected intensity value Va in this embodiment will be described with reference to Fig. 18. In this embodiment, the phase difference between the periodic component of the first detection signal S11 and the periodic component of the second detection signal S12 is an odd multiple of ¼ of the period of the periodic component. In this embodiment, in particular, the phase of the periodic component of the second detection signal S12 differs from the phase of the periodic component of the first detection signal S11 by 90°.

[0108] The processor 40 is configured to generate the angle detection value θs using the ratio of the second detection signal S12 to the first detection signal S11. The processor 40 calculates θs within the range of 0° or more and less than 360°, for example, using the following equation (6):

[0109] θs=atan(S12 / S11) …(6)

[0110] The processor 40 is also configured to generate the intensity detection value Va by using the sum of squares of the first and second detection signals S11, S12. The processor 40 may use the sum of squares of the first and second detection signals S11, S12 as the intensity detection value Va. Alternatively, the processor 40 may calculate Va using the following equation (7):

[0111]

number

[0112] Other configurations, actions, and effects of this embodiment are the same as those of the first or second embodiment.

[0113] [Fourth embodiment] Next, a magnetic sensor device according to a fourth embodiment of the present invention will be described with reference to Fig. 19. Fig. 19 is a circuit diagram showing the configuration of the magnetic sensor device according to this embodiment.

[0114] In this embodiment, the first detection circuit 110a and the second detection circuit 110b are configured with circuits having different configurations. The configuration of the first detection circuit 110a is the same as that of the third embodiment. The second detection circuit 110b is arranged to have the same posture as the first detection circuit 110a. In the second detection circuit 110b, the magnetization 51m of the magnetization fixed layer 51 in the MR element 111b includes a component in the -DR1 direction, and the magnetization 51m of the magnetization fixed layer 51 in the MR element 112b includes a component in the DR1 direction.

[0115] Other configurations, actions, and effects of this embodiment are the same as those of the third embodiment.

[0116] [Fifth embodiment] Next, a motion detection device according to a fifth embodiment of the present invention will be described with reference to Fig. 20. Fig. 20 is a perspective view showing the motion detection device according to this embodiment.

[0117] The motion detection device 200 according to this embodiment includes a component 201 and a main body 202 that houses at least a portion of the component 201. The component 201 is configured to be able to rotate in a direction D1 around a reference axis C and move in a direction D2 parallel to the reference axis C. The component 201 may be a component such as a knob that is operated by a human operation. Examples of the motion detection device 200 that includes such a component 201 include operating devices for an air conditioner or a car navigation system in an automobile, operating devices for a digital camera or a radio, and a crown for a smart watch. Alternatively, the component 201 may be a component that operates in conjunction with an arbitrary driving device.

[0118] The motion detection device 200 further includes a magnetic sensor device (not shown) and a magnetic field generator (not shown). The configuration of the magnetic sensor device is the same as the configuration of the magnetic sensor device 2 according to any one of the first to fourth embodiments. The configuration of the magnetic field generator is the same as the configuration of the magnetic field generator 5 according to any one of the first to fourth embodiments.

[0119] The magnetic field generator is configured to operate in conjunction with the part 201. The rotational position of the magnetic field generator in the direction D1 about the axis corresponds to the rotational position of the part 201 in the direction D1 about the axis. Also, the position of the magnetic field generator in the direction D2 corresponds to the position of the part 201 in the direction D2.

[0120] As explained in the first embodiment, the angle detection value generated by the magnetic sensor device corresponds to the rotational position of the magnetic field generator. The intensity detection value generated by the magnetic sensor device corresponds to the position of the magnetic field generator in direction D2. Therefore, according to this embodiment, magnetic sensor device Both the rotational position of the part 201 and the position of the part 201 in direction D2 can be detected by the angle detection value and intensity detection value generated by the above. The rotational position of the part 201 can be calculated, for example, using the angle detection value and the number of rotations of the part 201 (number of rotations of the magnetic field generator) counted from the angle detection value. The position of the part 201 in direction D2 can be calculated, for example, by multiplying the intensity detection value by a predetermined coefficient.

[0121] Other configurations, actions, and effects of this embodiment are the same as those of any of the first to fourth embodiments.

[0122] The present invention is not limited to the above-described embodiments and may be modified in various ways. For example, each of the first to third detection circuits 10a to 10c may include a full-bridge circuit formed of four MR elements.

[0123] As described above, the magnetic sensor device of the present invention includes a magnetic sensor configured to detect a target magnetic field and a processor. The magnetic sensor includes multiple detection circuits, each including a magnetoresistive element. The magnetoresistive element includes a magnetization fixed layer having a magnetization with a fixed direction and a free layer having a magnetic vortex structure and configured so that the center of the magnetic vortex structure moves in response to the target magnetic field. The multiple detection circuits are configured to generate multiple detection signals, each of which changes periodically in response to periodic changes in the direction of the target magnetic field and whose amplitude changes in response to changes in the strength of the target magnetic field. The processor is configured to generate, based on the multiple detection signals, an angle detection value corresponding to the angle that the direction of the target magnetic field makes with respect to a reference direction and an intensity detection value corresponding to the strength of the target magnetic field.

[0124] In the magnetic sensor device of the present invention, the multiple detection circuits may be a first detection circuit and a second detection circuit. The multiple detection signals may be a first detection signal generated by the first detection circuit and a second detection signal generated by the second detection circuit. The processor may be configured to generate an angle detection value using a ratio of the second detection signal to the first detection signal. The first detection signal and the second detection signal may each include periodic components that change with the same period. The phase difference between the periodic component of the first detection signal and the periodic component of the second detection signal may be an odd multiple of ¼ of the period. The processor may be configured to generate an intensity detection value using a sum of squares of the first detection signal and the second detection signal.

[0125] In the magnetic sensor device of the present invention, the multiple detection circuits may be a first detection circuit, a second detection circuit, and a third detection circuit. The multiple detection signals may be a first detection signal generated by the first detection circuit, a second detection signal generated by the second detection circuit, and a third detection signal generated by the third detection circuit. The processor may be configured to generate an angle detection value using a first signal corresponding to a difference between the first detection signal and the second detection signal, a second signal corresponding to a difference between the second detection signal and the third detection signal, and a third signal corresponding to a difference between the third detection signal and the first detection signal. The first detection signal, the second detection signal, and the third detection signal may each include periodic components that change with equal periods. The phase difference between the periodic component of the first detection signal and the periodic component of the second detection signal and the periodic component of the second detection signal and the periodic component of the third detection signal may each be 1 / 3 of the period. The phase difference between the periodic component of the first detection signal and the periodic component of the third detection signal may be 2 / 3 of the period. In the magnetic sensor device of the present invention, the processor may be configured to generate the detected intensity value using a sum of squares of the first signal, the second signal, and the third signal.

[0126] In the magnetic sensor device of the present invention, the free layer does not need to be saturated within the range of change in the intensity of the target magnetic field applied to the magnetoresistive element.

[0127] A magnetic sensor system of the present invention comprises the magnetic sensor device of the present invention and a magnetic field generator configured to generate a target magnetic field.

[0128] In the magnetic sensor system of the present invention, the magnetic sensor and the magnetic field generator may be configured such that the direction of the target magnetic field changes when at least one of the magnetic sensor and the magnetic field generator rotates in an axial direction centered on a reference axis, and the strength of the target magnetic field changes when at least one of the magnetic sensor and the magnetic field generator moves in a direction parallel to the reference axis. The magnetic field generator may be configured to rotate about the reference axis and move in a direction parallel to the reference axis. The processor may be configured to detect the rotational position of the magnetic field generator using the angle detection value and to detect the position of the magnetic field generator in a direction parallel to the reference axis using the intensity detection value. The magnetic sensor may be positioned ahead of the movement direction of the magnetic field generator in the direction parallel to the reference axis. The target magnetic field may include a component in a direction perpendicular to the reference axis.

[0129] The motion detection device of the present invention comprises a component configured to be able to rotate around a reference axis and move in a direction parallel to the reference axis, the magnetic sensor device of the present invention, and a magnetic field generator configured to generate a target magnetic field and to operate in conjunction with the component. [Explanation of symbols]

[0130] 1...magnetic sensor, 2...magnetic sensor device, 5...magnetic field generator, 7...support, 10...detection circuit, 10a...first detection circuit, 10b...second detection circuit, 10c...third detection circuit, 11, 11a, 11b, 11c, 12, 12a, 12b, 12c...MR element, 31, 32, 33...differential detector, 40...processor, 50...laminated film, 51...magnetization fixed layer, 51m...magnetization, 52...gap layer, 53...free layer, 53m...magnetization, 61...lower electrode, 62...upper electrode , 100...magnetic sensor system, C...reference axis, E1, E2, E3...output port, G1, G2, G3...ground port, MF...target magnetic field, P1...first position, P2...second position, P3...third position, PR...reference position, S1...first detection signal, S2...second detection signal, S3...third detection signal, Sa...first signal, Sb...second signal, Sc...third signal, V1, V2, V3...power supply port, Va...intensity detection value, θM...rotation angle, θs...angle detection value.

Claims

1. 1. A magnetic sensor device comprising: a magnetic sensor configured to detect a target magnetic field; and a processor, the magnetic sensor includes a plurality of detection circuits each including a magnetoresistive element; the magnetoresistive element includes a magnetization fixed layer having a magnetization whose direction is fixed, and a free layer having a magnetic vortex structure and configured such that the center of the magnetic vortex structure moves in response to the target magnetic field; the plurality of detection circuits are configured to generate a plurality of detection signals, each of which periodically changes in response to a periodic change in the direction of the target magnetic field and whose amplitude changes in response to a change in the strength of the target magnetic field; the processor is configured to generate, based on the plurality of detection signals, an angle detection value corresponding to an angle that a direction of the target magnetic field makes with respect to a reference direction and an intensity detection value corresponding to an intensity of the target magnetic field; 10. A magnetic sensor device according to claim 9, wherein the free layer does not saturate within a range of change in the intensity of the target magnetic field applied to the magnetoresistive element.

2. the plurality of detection circuits are a first detection circuit and a second detection circuit; the plurality of detection signals are a first detection signal generated by the first detection circuit and a second detection signal generated by the second detection circuit; 2. The magnetic sensor device according to claim 1, wherein the processor is configured to generate the angle detection value using a ratio of the second detection signal to the first detection signal.

3. the first detection signal and the second detection signal each include a periodic component that changes at a period equal to each other; 3. The magnetic sensor device according to claim 2, wherein the phase difference between the periodic component of the first detection signal and the periodic component of the second detection signal is an odd multiple of 1 / 4 of the period.

4. 4. The magnetic sensor device according to claim 3, wherein the processor is configured to generate the intensity detection value using a sum of squares of the first detection signal and the second detection signal.

5. the plurality of detection circuits are a first detection circuit, a second detection circuit, and a third detection circuit; the plurality of detection signals are a first detection signal generated by the first detection circuit, a second detection signal generated by the second detection circuit, and a third detection signal generated by the third detection circuit; The magnetic sensor device according to claim 1, characterized in that the processor is configured to generate the angle detection value using a first signal corresponding to a difference between the first detection signal and the second detection signal, a second signal corresponding to a difference between the second detection signal and the third detection signal, and a third signal corresponding to a difference between the third detection signal and the first detection signal.

6. the first detection signal, the second detection signal, and the third detection signal each include a periodic component that changes at a period equal to one another; a phase difference between the periodic component of the first detection signal and the periodic component of the second detection signal, and a phase difference between the periodic component of the second detection signal and the periodic component of the third detection signal are both ⅓ of the period; 6. The magnetic sensor device according to claim 5, wherein the phase difference between the periodic component of the first detection signal and the periodic component of the third detection signal is 2 / 3 of the period.

7. 6. The magnetic sensor device according to claim 5, wherein the processor is configured to generate the intensity detection value using a sum of squares of the first signal, the second signal, and the third signal.

8. The magnetic sensor device according to any one of claims 1 to 7, a magnetic field generator configured to generate the target magnetic field.

9. 9. The magnetic sensor system of claim 8, wherein the magnetic sensor and the magnetic field generator are configured such that when at least one of the magnetic sensor and the magnetic field generator rotates in an axial direction centered on a reference axis, the direction of the target magnetic field changes, and when at least one of the magnetic sensor and the magnetic field generator moves in a direction parallel to the reference axis, the strength of the target magnetic field changes.

10. the magnetic field generator is configured to rotate about the reference axis and move in a direction parallel to the reference axis; 10. The magnetic sensor system of claim 9, wherein the processor is configured to use the angle detection values ​​to detect a rotational position of the magnetic field generator and to use the intensity detection values ​​to detect a position of the magnetic field generator in a direction parallel to the reference axis.

11. The magnetic sensor system according to claim 9 , wherein the magnetic sensor is disposed ahead of the magnetic field generator in a direction parallel to the reference axis.

12. 10. The magnetic sensor system according to claim 9, wherein the target magnetic field includes a component in a direction perpendicular to the reference axis.

13. A component configured to be able to rotate around a reference axis and move in a direction parallel to the reference axis; The magnetic sensor device according to any one of claims 1 to 7, a magnetic field generator configured to generate the target magnetic field and configured to operate in conjunction with the component.

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