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

Abstract

The invention relates to a magnetic sensor device, a magnetic sensor system and a motion detection device. The magnetic sensor device includes a magnetic sensor and a processor. Each of a plurality of detection circuits of the magnetic sensor includes an MR element. The MR element includes a free layer having a magnetic eddy current structure and configured such that the center of the magnetic eddy current structure moves in accordance with a target magnetic field. The plurality of detection circuits are configured so as to generate a plurality of detection signals that periodically change in accordance with a periodic change in the direction of the target magnetic field and that have amplitudes that change in accordance with a change in the intensity of the target magnetic field. The processor is configured to generate an angle detection value and an intensity detection value based on the plurality of detection signals.

Description

Technical Field

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

[0002] In recent years, angle sensors that generate angle detection values ​​that correspond to the angle of a detection object have been widely used in various applications such as detecting the rotational position of a steering wheel or a power steering motor of a car. As an angle sensor, for example, there is an angle sensor using a magnetic detection element. In an angle sensor system using a magnetic detection element, a magnetic field generator is usually provided, which generates a magnetic field of the detection object that rotates in a direction linked to the rotation or linear motion of the object. The magnetic field generator is, for example, a magnet. The angle of the detection object corresponds to the angle formed by the direction of the detection object magnetic field at the reference position relative to the reference direction.

[0003] As the magnetic detection element, for example, a spin valve type magnetoresistive effect element can be used. The spin valve type magnetoresistive effect element has: a magnetization fixed layer having magnetization whose direction is fixed; a free layer having magnetization whose direction can be changed according to the direction of the applied magnetic field; and a gap layer arranged between the magnetization fixed layer and the free layer.

[0004] As an angle sensor using a spin valve type magnetoresistive effect element, as disclosed in Chinese Patent Application Publication No. 113811738A, there is known an angle sensor comprising two detection circuits, each of which comprises a bridge circuit using a magnetoresistive effect element, and the phases of the output characteristics of the two detection circuits are different from each other. In Chinese Patent Application Publication No. 113811738A, in addition to the angle sensor, a magnetic field intensity sensor using a magnetoresistive effect element is also disclosed, and the magnetoresistive effect element comprises a free layer having a magnetic eddy current structure (also called a vortex structure). The angle sensor and the magnetic field intensity sensor are arranged on the same substrate to constitute a magnetic sensor.

[0005] In an angle sensor system, it is sometimes required to detect both the rotation and linear motion of an object. In this case, it is considered to use a magnetic sensor such as that disclosed in Chinese Patent Application Publication No. 113811738A to detect both the direction and intensity of the magnetic field of the detection object. However, in the magnetic sensor disclosed in Chinese Patent Application Publication No. 113811738A, there is a problem that it is difficult to miniaturize the magnetic sensor because the angle sensor and the magnetic field intensity sensor are separately provided. Summary of the invention

[0006] An object of the present invention is to provide a magnetic sensor device capable of detecting both the direction and the intensity of a target magnetic field with a simple structure, and a magnetic sensor system and a motion detection device each including the magnetic sensor device.

[0007] The magnetic sensor device of the present invention comprises: a magnetic sensor configured to detect an object magnetic field, and a processor. The magnetic sensor includes a plurality of detection circuits each including a magnetoresistive effect element. The magnetoresistive effect element includes: a magnetization fixed layer having magnetization whose direction is fixed, and a free layer having a magnetic eddy current structure and configured such that the center of the magnetic eddy current structure moves according to the object magnetic field. The plurality of detection circuits are configured to generate a plurality of detection signals that periodically change according to the periodic change of the direction of the object magnetic field and whose amplitude changes according to the change of the intensity of the object magnetic field. The processor is configured to generate an angle detection value corresponding to the angle formed by the direction of the object magnetic field relative to the reference direction, and an intensity detection value corresponding to the intensity of the object magnetic field based on the plurality of detection signals.

[0008] A magnetic sensor system according to the present invention includes the magnetic sensor device according to the present invention and a magnetic field generator configured to generate a target magnetic field.

[0009] The motion detection device of the present invention comprises: a component, which is configured 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, which is configured to generate a target magnetic field and is configured to operate in conjunction with the component.

[0010] In the magnetic sensor device of the present invention, the plurality of detection circuits respectively include a magnetoresistive effect element, and the magnetoresistive effect element includes a free layer having a magnetic eddy current structure and configured so that the center of the magnetic eddy current structure moves according to the 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. Thus, according to the present invention, both the direction and the intensity of the target magnetic field can be detected by a simple structure.

[0011] Other objects, features and advantages of the present invention will become more apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a perspective view showing the magnetic sensor system according to the first embodiment of the present invention.

[0013] Figure 2 It is a top view showing the magnetic sensor system according to the first embodiment of the present invention.

[0014] Figure 3 It is an explanatory diagram for explaining the target magnetic field according to the first embodiment of the present invention.

[0015] Figure 4 : is a circuit diagram showing the structure of the magnetic sensor device according to the first embodiment of the present invention.

[0016] Figure 5 It is a perspective view showing a part of the magnetoresistive effect element according to the first embodiment of the present invention.

[0017] Figure 6 It is a perspective view showing a stacked film of the magnetoresistive effect element according to the first embodiment of the present invention.

[0018] Figure 7 It is a plan view showing a free layer of a stacked film of the magnetoresistive element according to the first embodiment of the present invention.

[0019] Figure 8 This is a plan view showing the free layer when a target magnetic field is applied to the magnetoresistive element according to the first embodiment of the present invention.

[0020] Fig. 9 This is a plan view showing the free layer when a target magnetic field is applied to the magnetoresistive element according to the first embodiment of the present invention.

[0021] Fig.10 This is a characteristic diagram showing the relationship between the intensity of the magnetic field component and the magnitude of magnetization of the entire free layer according to the first embodiment of the present invention.

[0022] Fig.11 : is a waveform diagram showing the waveforms of the first to third detection signals of the first example in the first embodiment of the present invention.

[0023] Fig.12 : is a waveform diagram showing the waveforms of the first and second angle calculation signals of the first example in the first embodiment of the present invention.

[0024] Fig.13 : is a characteristic diagram showing the intensity detection value of the first example in the first embodiment of the present invention.

[0025] Fig.14 : is a waveform diagram showing the waveforms of the first to third detection signals of the second example in the first embodiment of the present invention.

[0026] Fig.15 : is a waveform diagram showing the waveforms of the first and second angle calculation signals of the second example in the first embodiment of the present invention.

[0027] Fig.16 : is a characteristic diagram showing the intensity detection value of the second example in the first embodiment of the present invention.

[0028] Fig.17It is a perspective view showing a magnetic sensor system according to a second embodiment of the present invention.

[0029] Fig.18 : is a circuit diagram showing the structure of a magnetic sensor device according to a third embodiment of the present invention.

[0030] Fig.19 : is a circuit diagram showing the structure of a magnetic sensor device according to a fourth embodiment of the present invention.

[0031] Fig. 20 It is a perspective view showing a motion detection device according to a fifth embodiment of the present invention. DETAILED DESCRIPTION

[0032] [First embodiment]

[0033] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Figure 1 and Figure 2 The configuration of the magnetic sensor system according to the first embodiment of the present invention will be described. Figure 1 1 is a perspective view showing the magnetic sensor system 100 according to the present embodiment. Figure 2 1 is a plan view showing a magnetic sensor system 100 according to the present embodiment. The magnetic sensor system 100 according to the present embodiment is a magnetic angle sensor system, and includes a magnetic sensor 1 and a magnetic field generator 5 .

[0034] The magnetic field generator 5 generates a magnetic field of the detection object related to the angle of the detection object. Hereinafter, the magnetic field of the detection object of the magnetic sensor 1 is referred to as the target magnetic field MF. The magnetic field generator 5 of the present embodiment is a cylindrical magnet. The magnetic field generator 5 has an N pole and an S pole symmetrically arranged around an imaginary plane containing the central axis of the cylinder. The magnetic field generator 5 is configured to rotate in an axial direction D1 around the central axis of the cylinder. As a result, the direction of the target magnetic field MF rotates around the reference axis C containing the central axis of the cylinder. The magnetic field generator 5 is also configured to move in a direction D2 parallel to the reference axis C.

[0035] Here, the angle of the detection target is referred to as a target angle and is represented by symbol θ. The target angle θ in the present embodiment is an angle corresponding to the rotation angle θM of the magnetic field generator 5 .

[0036] Figure 3 is an explanatory diagram for explaining the target magnetic field MF. Figure 3In the figure, the symbol P represents an imaginary plane perpendicular to the reference axis C, namely the reference plane. In the reference plane P, the direction of the object magnetic field MF rotates around the position on the reference axis C, namely the reference position PR. The reference direction DR is located in the reference plane P and intersects with the reference position PR. In the following description, the direction of the object magnetic field MF refers to the direction located in the reference plane P. The object angle θ is the angle between the direction of the object magnetic field MF and the reference direction DR. Figure 3 In FIG. 5 , for convenience, the symbol θ is used to represent the angle between the direction of the target magnetic field MF and the reference direction DR.

[0037] exist Figure 3 In FIG. 1 , the direction of the target magnetic field MF rotates counterclockwise. When viewed from the reference direction DR in the counterclockwise direction, the target angle θ is represented by a positive value, and when viewed from the reference direction DR in the clockwise direction, the target angle θ is represented by a negative value.

[0038] The magnetic sensor 1 is configured to detect the target magnetic field MF and generate at least one detection signal corresponding to the target angle θ. In the present embodiment, the magnetic sensor 1 is configured to detect the target magnetic field MF at each of a plurality of specific positions away from the reference axis C.

[0039] 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 surface of the magnetic field generator 5, that is, a cylindrical magnet.

[0040] The first to third detection circuits 10a to 10c may each have a chip form or a package form sealed by a 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 also have a package form in which the first to third detection circuits 10a to 10c are sealed by a sealing resin.

[0041] The first detection circuit 10a is configured to detect the target magnetic field MF at a first position P1 separated from the reference axis C, and to generate a first detection signal S1 that periodically changes according to the periodic change of the target magnetic field MF and whose amplitude changes according to the change 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 separated from the reference axis C, and to generate a second detection signal S2 that periodically changes according to the periodic change of the target magnetic field MF and whose amplitude changes according to the change 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 separated from the reference axis C, and to generate a third detection signal S3 that periodically changes according to the periodic change of the target magnetic field MF and whose amplitude changes according to the change 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 consistent with the direction and intensity of the target magnetic field MF at the reference position PR.

[0042] The first to third detection signals S1 to S3 may also respectively include periodic components that change with equal periods. In the present embodiment, in particular, the periodic component changes periodically with a predetermined signal period to depict an ideal sinusoidal curve (including a sine waveform and a cosine waveform). When the magnetic field generator 5 rotates one circle, that is, 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 also be equal to each other.

[0043] The first to third positions P1 to P3 are described in detail below. The first to third positions P1 to P3 may be positions on the reference plane P, respectively. 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 located on the reference plane P. The first to third positions P1 to P3 may be located on an imaginary circle centered on the reference position PR.

[0044] like Figure 2 As shown, the second position P2 is a position rotated from the first position P1 by an angle θ1 about the reference axis C. The third position P3 is a position rotated from the first position P1 by an angle θ2 about the reference axis C.

[0045] Here, the period of the periodic component is set to 360° in electrical angle. Angle θ1 is equivalent to 120° in electrical angle. Angle θ2 is equivalent to 240° in electrical angle. In this embodiment, in particular, the angle equivalent to 120° in electrical angle is also physically 120°, and the angle equivalent to 240° in electrical angle is also physically 240°.

[0046] Here, if Figure 1 to Figure 3 As shown in FIG. 1 , the U direction, V direction, W direction and Z direction are defined. Figure 1 The reference axis C shown is parallel to and extends from Figure 1 The direction from the bottom to the top is set as Z direction. Figure 2 and Figure 3 In the example, the Z direction is represented as Figure 2 and Figure 3 In addition, the direction perpendicular to the Z direction and from the reference axis C toward the first position P1 is defined as the U direction, the direction perpendicular to the Z direction and from the reference axis C toward the second position P2 is defined as the V direction, and the direction perpendicular to the Z direction and from the reference axis C toward the third position P3 is defined as the W direction. In this embodiment, the V direction is a direction perpendicular to the U direction. Figure 2 and Figure 3 The direction after rotating 120° counterclockwise in the direction of rotation. In addition, the W direction is the direction from the V direction Figure 2 and Figure 3 The counterclockwise direction in the image is rotated 120° and the direction from the U direction is Figure 2 and Figure 3 The direction after rotating 120° from the clockwise direction in . In addition, the direction opposite to the U direction is set as the -U direction, the direction opposite to the V direction is set as the -V direction, the direction opposite to the W direction is set as the -W direction, and the direction opposite to the Z direction is set as the -Z direction. Hereinafter, the coordinate system based on the reference axis C is referred to as the reference coordinate system.

[0047] Hereinafter, in the reference coordinate system and the orthogonal coordinate system described later, the position at the front end in the Z direction relative to the reference position is referred to as "upper", and the position on the opposite side of the "upper" relative to the reference position is referred to as "lower". In addition, in the present embodiment, the reference direction DR is set to the U direction.

[0048] The magnetic sensor 1 further includes a support body 7 that supports the first to third detection circuits 10a to 10c. The support body 7 is arranged at a predetermined interval relative to the magnetic field generator 5 in a direction parallel to the reference axis C. The support body 7 has an upper surface 7a opposite to the magnetic field generator 5. The upper surface 7a may also 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. Figure 2 In the illustrated example, the first to third detection circuits 10 a to 10 c are arranged on the upper surface 7 a of the support body 7 .

[0049] In addition, the structure of the magnetic sensor system 100 of this embodiment is not limited to Figure 1The magnetic sensor system 100 of this embodiment can be configured such that 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 when viewed from the magnetic sensor 1. Figure 1 In the magnetic field generator 5 and the magnetic sensor 1 configured as shown, the magnetic field generator 5 can be fixed and the magnetic sensor 1 can be rotated in the axial direction D1, the magnetic field generator 5 and the magnetic sensor 1 can be rotated in opposite directions in the axial direction D1, or the magnetic field generator 5 and the magnetic sensor 1 can be rotated in the same direction in the axial direction D1 at different angular velocities.

[0050] In addition, the structure of the magnetic sensor system 100 of this embodiment can be any structure as long as 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. Figure 1 In the magnetic field generator 5 and the magnetic sensor 1 configured as shown, the magnetic field generator 5 can be fixed and the magnetic sensor 1 can be moved along the direction D2, the magnetic field generator 5 and the magnetic sensor 1 can be moved in opposite directions in the direction D2, or the magnetic field generator 5 and the magnetic sensor 1 can be moved in the same direction in the direction D2 by different distances. In addition, the reference position PR moves with the movement of the magnetic sensor 1.

[0051] Next, refer to Figure 4 The structure of the magnetic sensor 1 will be described in detail. Figure 4 : is a circuit diagram showing the structure of the magnetic sensor device according to this embodiment.

[0052] The magnetic sensor device 2 of the present embodiment includes a magnetic sensor 1 and a processor 40. The processor 40 is configured to generate an angle detection value θs corresponding to the angle θ formed by the direction of the target magnetic field MF relative to the reference direction DR, and an intensity detection value Va corresponding to the intensity of the target magnetic field MF at a predetermined position based on the first to third detection signals S1 to S3. The predetermined position may also be a reference position PR.

[0053] The processor 40 can be implemented, for example, by an application specific integrated circuit (ASIC) or a microcomputer. The processor 40 may be included in Figure 2 The support body 7 shown may be arranged at a position away from the first to third detection circuits 10 a to 10 c and the magnetic field generator 5 .

[0054] The first detection circuit 10a includes a first magnetic detection element. The characteristics of the first magnetic detection element change according to the object magnetic field MF at the first position P1, that is, the object magnetic field MF applied to the first detection circuit 10a. In the present embodiment, in particular, the first detection circuit 10a includes two magnetoresistive effect elements (hereinafter referred to as MR elements) 11a and 12a as the first magnetic detection element. The first detection circuit 10a also includes a power supply port V1, a ground port G1, and an output port E1. The MR element 11a is arranged between the power supply port V1 and the output port E1 in terms of circuit structure. The MR element 12a is arranged between the ground port G1 and the output port E1 in terms of circuit structure. A voltage or current of a specified magnitude is applied to the power supply port V1. The ground port G1 is grounded. In addition, in the present application, the expression "circuit structure" is used to indicate the configuration on the circuit diagram, rather than the configuration on the physical structure.

[0055] The second detection circuit 10b includes a second magnetic detection element. The characteristics of the second magnetic detection element vary according to the object magnetic field MF at the second position P2, that is, the object magnetic field MF applied to the second detection circuit 10b. In the present embodiment, in particular, the second detection circuit 10b includes two MR elements 11b and 12b as second magnetic detection elements. The second detection circuit 10b also includes a power supply port V2, a ground port G2, and an output port E2. The MR element 11b is arranged between the power supply port V2 and the output port E2 in terms of circuit structure. The MR element 12b is arranged between the ground port G2 and the output port E2 in terms of circuit structure. A voltage or current of a specified size is applied to the power supply port V2. The ground port G2 is grounded.

[0056] The third detection circuit 10c includes a third magnetic detection element. The characteristics of the third magnetic detection element vary according to the object magnetic field MF at the third position P3, that is, the object magnetic field MF applied to the third detection circuit 10c. In the present embodiment, in particular, the third detection circuit 10c includes two MR elements 11c and 12c as third magnetic detection elements. The third detection circuit 10c also includes a power supply port V3, a ground port G3, and an output port E3. The MR element 11c is arranged between the power supply port V3 and the output port E3 in terms of circuit structure. The MR element 12c is arranged between the ground port G3 and the output port E3 in terms of circuit structure. A voltage or current of a specified size is applied to the power supply port V3. The ground port G3 is grounded.

[0057] 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.

[0058] The first to third signals Sa to Sc may also be generated by digital signal processing. That is, the differential detectors 31, 32, and 33 may also be respectively formed by differential analog-to-digital converters such as ASICs or microcomputers. In this case, the differential detectors 31, 32, and 33 may also be integrated with the processor 40. Alternatively, the first to third signals Sa to Sc may also be generated by analog signal processing. That is, the differential detectors 31, 32, and 33 may also be respectively formed by circuits using operational amplifiers. In this case, the differential detectors 31, 32, and 33 may be integrated with the processor 40 or may be separated from the processor 40.

[0059] Here, any detection circuit among the first to third detection circuits 10a to 10c is denoted by reference numeral 10. In addition, among the MR elements included in the detection circuit 10, reference numeral 11 is used for MR elements corresponding to the MR elements 11a, 11b, and 11c, and reference numeral 12 is used for MR elements corresponding to the MR elements 12a, 12b, and 12c.

[0060] Below, refer to Figure 5 The structure of the MR elements 11 and 12 will be described in detail. Figure 5 It is a perspective view showing a part of the MR elements 11 and 12 .

[0061] The MR elements 11 and 12 each include at least one stacked film. In particular, in the present embodiment, the MR elements 11 and 12 each include a plurality of stacked films 50 connected in series as at least one stacked film. The MR elements 11 and 12 each further include a plurality of lower electrodes 61 and a plurality of upper electrodes 62. The plurality of lower electrodes 61 each have an elongated shape. A gap is formed between two lower electrodes 61 adjacent in the long side direction of the lower electrode 61. On the upper surface of each lower electrode 61, a stacked film 50 is disposed near both ends in the long side direction of the lower electrode 61. The plurality of upper electrodes 62 each have an elongated shape, and electrically connect two adjacent stacked films 50 disposed on two lower electrodes 61 adjacent in the long side direction of the lower electrode 61.

[0062] Although not shown in the figure, one stacked film 50 located at one end of a row of a plurality of stacked films 50 arranged in a row is connected to another stacked film 50 located at one end of another row of a plurality of stacked films 50 adjacent in a direction intersecting the long side direction of the lower electrode 61. The two stacked films 50 are connected to each other by an electrode not shown in the figure. The electrode not shown in the figure may also be an electrode that connects the lower surfaces or upper surfaces of the two stacked films 50.

[0063] 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 with the insulating layer.

[0064] The magnetic sensor 1 further includes a plurality of electrode pads not shown. The plurality of electrode pads include a power port electrode pad corresponding to the power 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 are electrically connected to the MR elements 11 and 12.

[0065] Next, refer to Figure 6 and Figure 7 The structure of the stacked film 50 of each of the MR elements 11 and 12 will be described. Figure 6 It is a perspective view showing the stacked films of the MR elements 11 and 12 . Figure 7 It is a plan view showing the free layer of the stacked film of the MR elements 11 and 12 .

[0066] Here, if Figure 6 and Figure 7 As shown in FIG. 1 , the X direction, Y direction, and Z direction are defined. The X direction, Y direction, and Z direction are orthogonal to each other. In addition, the direction opposite to the X direction is defined as the −X direction, and the direction opposite to the Y direction is defined as the −Y direction. Figure 6 and Figure 7 The orthogonal coordinate system defined by the X direction, Y direction, and Z direction shown in FIG. 1 is a coordinate system defined based on the detection circuit 10. The Z direction of the orthogonal coordinate system is Figure 1 The Z direction of the reference coordinate system defined by the reference axis C shown is consistent.

[0067] The laminated film 50 includes a magnetization-fixed layer 51 having magnetization 51m whose direction is fixed, a free layer 53, and a gap layer 52 disposed between the magnetization-fixed layer 51 and the free layer 53. The free layer 53 is selected in material and shape 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.

[0068] The free layer 53 has a cylindrical or substantially cylindrical shape. In addition, the free layer 53 has a magnetization 53m that is swirled around the center 53c of the magnetic vortex structure. In a state where there is no magnetic field applied to the stacked film 50, the center 53c of the magnetic vortex structure is consistent with or substantially consistent with the axis of the cylinder. The center 53c of the magnetic vortex structure moves according to the target magnetic field MF. In addition, in Figure 6 and Figure 7 In the example shown, the entire laminate film 50 has a cylindrical shape.

[0069] The center 53c of the magnetic eddy current structure moves when a component in the direction perpendicular to the Z direction in the target magnetic field MF is applied to the free layer 53. It is preferable that the free layer 53 is not saturated within a range in which the intensity of this component changes.

[0070] The magnetization 51m of the magnetization fixed layer 51 includes a component in a direction 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 directions opposite to each other.

[0071] In addition, 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 orthogonal to the specific direction. In the present 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 is a specific direction or a substantially specific direction.

[0072] The laminated film 50 may also include an antiferromagnetic layer. The antiferromagnetic layer is made of an antiferromagnetic material, generates exchange coupling with the magnetization fixed layer 51, and fixes the direction of the magnetization 51m of the magnetization fixed layer 51. Alternatively, the magnetization fixed layer 51 may be a so-called self-pinned fixed layer (synthetic ferri pinned layer, SFP layer). The self-pinned fixed layer has a laminated ferrite structure in which a ferromagnetic layer, a non-magnetic intermediate layer, and a ferromagnetic layer are laminated, and is formed by antiferromagnetically coupling two ferromagnetic layers.

[0073] Here, the resistance value of the stacked film 50 will be described by taking the case where the direction of the magnetization 51 m of the magnetization fixed layer 51 is the −X direction as an example. Figure 8 and Fig. 9 The free layer 53 is shown 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 .

[0074] Figure 8The free layer 53 is shown when the direction of the magnetic field component MFx is the X direction. In this case, the center 53c of the magnetic vortex structure moves due to the magnetic field component MFx, and the amount of magnetization 53m in the X direction is greater than the amount of magnetization 53m in the -X direction. In this case, the resistance value of the stacked film 50 increases.

[0075] Fig. 9 The free layer 53 is shown when the direction of the magnetic field component MFx is the -X direction. In this case, the center 53c of the magnetic vortex structure moves due to the magnetic field component MFx, and the amount of magnetization 53m in the -X direction is greater than the amount of magnetization 53m in the X direction. In this case, the resistance value of the stacked film 50 decreases.

[0076] The amount of change in the resistance value of the stacked 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, when the strength of the magnetic field component MFx increases, the amount of magnetization 53m in the X direction increases. The resistance value of the stacked film 50 increases as the amount of magnetization 53m in the X direction increases. In addition, when the direction of the magnetic field component MFx is the -X direction, when the strength of the magnetic field component MFx increases, the amount of magnetization 53m in the -X direction increases. The resistance value of the stacked film 50 decreases as the amount of magnetization 53m in the -X direction increases. When the strength of the magnetic field component MFx increases, the resistance value of the stacked film 50 changes in a direction in which the increase or decrease increases. When the strength of the magnetic field component MFx decreases, the resistance value of the stacked film 50 changes in a direction in which the increase or decrease decreases.

[0077] 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 to which each of the plurality of stacked films 50 is subjected. When 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 thereof increases. When 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 thereof 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.

[0078] 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 include components in opposite directions. Therefore, when the direction and intensity of the target magnetic field MF applied to the detection circuit 10 change, the resistance values ​​of the MR elements 11 and 12 change so that the resistance value of the MR element 12 decreases as the resistance value of the MR element 11 increases, or the resistance value of the MR element 12 increases as the resistance value of the MR element 11 decreases. As a result, the potential of the connection point between the MR element 11 and the MR element 12 changes.

[0079] The first detection circuit 10a generates a signal corresponding to the potential of the output port E1 connected to the connection point of the MR element 11a and the MR element 12a as the first detection signal S1. The second detection circuit 10b generates a signal corresponding to the potential of the output port E2 connected to the connection point of the MR element 11b and the MR element 12b as the second detection signal S2. The third detection circuit 10c generates a signal corresponding to the potential of the output port E3 connected to the connection point of the MR element 11c and the MR element 12c as the third detection signal S3.

[0080] Here, refer to Fig.10 The relationship between the intensity of the magnetic field component MFx and the magnitude of magnetization of the entire free layer 53 will be described. Fig.10 : is a characteristic diagram schematically showing the relationship between the intensity of the magnetic field component MFx and the magnitude of the magnetization of the free layer 53 as a whole. Fig.10 In FIG. 5 , the horizontal axis represents the intensity Hx of the magnetic field component MFx, and the vertical axis represents the magnitude Mx of the magnetization of the free layer 53 as a whole. Fig.10 In the figure, the intensity Hx when the direction of the magnetic field component MFx is the X direction is represented by a positive value, and the intensity 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, when the amount of magnetization 53m toward the X direction increases, the magnitude Mx of the magnetization of the free layer 53 as a whole becomes larger. When the direction of the magnetic field component MFx is the -X direction, when the amount of magnetization 53m toward the -X direction increases, the magnitude Mx of the magnetization of the free layer 53 as a whole becomes smaller.

[0081] First, the case where the intensity Hx is increased from 0 will be described. When the intensity Hx is gradually increased from 0, the magnitude Mx of magnetization gradually increases. When the intensity Hx reaches a value Hx1 or more, the magnitude Mx of magnetization becomes constant, and the free layer 53 is saturated.

[0082] Next, the case where the intensity Hx is reduced from 0 will be described. When the intensity Hx is gradually reduced from 0, the magnitude Mx of magnetization is also gradually reduced. When the intensity Hx becomes equal to or less than the value Hx2, the magnitude Mx of magnetization becomes constant, and the free layer 53 is saturated.

[0083] like Fig.10 As shown, within a specified range where the intensity Hx is greater than the value Hx2 and less than the value Hx1, the magnitude Mx of the magnetization changes linearly with respect to the change in the intensity Hx. In addition, "linearly changes" means that in the characteristic diagram showing the relationship between the intensity Hx and the magnitude Mx of the magnetization, the magnitude Mx of the magnetization changes linearly or approximately linearly with respect to the change in the intensity Hx.

[0084] In the present embodiment, it is preferred that the free layer 53 is not saturated within the range of change in the intensity Hx, and it is more preferred that the magnitude Mx of magnetization changes linearly with respect to the change in the intensity Hx.

[0085] Furthermore, when the intensity Hx is greater than the value Hx1 and the free layer 53 is saturated, the magnitude Mx of magnetization hardly changes until the intensity Hx is reduced from the value Hx3 greater than the value Hx1 to the value Hx4 less than the value Hx1. When the intensity Hx is smaller than the value Hx4, the magnitude Mx of magnetization changes linearly with respect to the change in the intensity Hx, similarly to the case where the intensity Hx is changed within a prescribed range greater than the value Hx2 and less than the value Hx1.

[0086] Similarly, when the intensity Hx is reduced from a value Hx5 smaller than the ratio Hx2 after the intensity Hx is smaller than the ratio Hx2 and the free layer 53 is saturated, the magnitude Mx of the magnetization hardly changes until the intensity Hx reaches a value Hx6 larger than the ratio Hx2. When the intensity Hx is larger than the ratio Hx6, the magnitude Mx of the magnetization changes linearly with respect to the change in the intensity Hx, similarly to the case where the intensity Hx is changed within a prescribed range larger than the ratio Hx2 and smaller than the ratio Hx1.

[0087] Next, Figure 1 to Figure 4 The reference coordinate system shown is the same as Figure 6 to Figure 9 The relationship between the orthogonal coordinate systems shown is explained. Figure 6 to Figure 9 The orthogonal coordinate system shown is defined for each of 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 the direction after rotating 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 the direction after rotating 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 the direction after rotating 90° from the W direction in the reference coordinate system toward the U direction in the reference coordinate system.

[0088] In addition, Figure 4In the figure, each of the stacked films 50 is schematically shown as a figure representing the MR elements 11a, 11b, 11c, 12a, 12b, and 12c. The arrows drawn in the stacked film 50 indicate the direction of the magnetization 51m of the magnetization fixed layer 51 of the stacked 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 10 c , the magnetization 51 m of the magnetization fixed layer 51 in the MR element 11 c includes a component in the −W direction, and the magnetization 51 m of the magnetization fixed layer 51 in the MR element 12 c includes a component in the W direction.

[0089] Next, refer to Figure 4 The method for generating the angle detection value θs and the intensity detection value Va is described. The following description includes a description of the operation of the processor 40. In the present 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 can be 1 / 3 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 1 / 3 of the period of the periodic component, that is, 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 1 / 3 of the period of the periodic component, that is, 120°. In addition, the phase difference between the periodic component of the first detection signal S1 and the periodic component of the third detection signal S3 can also be 2 / 3 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 2 / 3 of the period of the periodic component, that is, 240°.

[0090] The first signal Sa output from the difference detector 31 , the second signal Sb output from the difference detector 32 , and the third signal Sc output from the difference detector 33 are respectively expressed by the following equations (1), (2), and (3).

[0091] Sa=S1-S2…(1)

[0092] Sb=S2-S3…(2)

[0093] Sc=S3-S1…(3)

[0094] The first signal Sa is equivalent to the difference between the first detection signal S1 and the second detection signal S2. The second signal Sb is equivalent to the difference between the second detection signal S2 and the third detection signal S3. The third signal Sc is equivalent to the difference between the third detection signal S3 and the first detection signal S1. The processor 40 can also be configured to generate an angle detection value θs using the first to third signals Sa to Sc. The processor 40 calculates θs within a range of 0° to less than 360°, for example, by the following formula (4).

[0095] Also, "atan" means inverse tangent.

[0096]

[0097] Here, the signal obtained by multiplying the first signal Sa by the square root of 3 is referred to as the first angle calculation signal Sd1, and the signal obtained by subtracting the second signal Sb from the third signal Sc is referred to as the second angle calculation signal Sd2. As can be understood from formula (4), the angle detection value θs can be calculated by obtaining the arc tangent of the ratio of the first angle calculation signal Sd1 to the second angle calculation signal Sd2.

[0098] In addition, the processor 40 may be configured to use the square sum of the first to third signals Sa to Sc to generate the intensity detection value Va. The processor 40 may also set the square sum 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 formula (5).

[0099]

[0100] In addition, the processor 40 may be configured to detect the rotational position of the magnetic field generator 5 using the angle detection value θs, and to detect the position of the magnetic field generator 5 in the direction D2 parallel to the reference axis C using the intensity detection value Va. The rotational position of the magnetic field generator 5 can be calculated, for example, using the angle detection value θs and the number of revolutions of the magnetic field generator 5 counted by the angle detection 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 intensity detection value Va by a predetermined coefficient.

[0101] Next, a method for manufacturing the magnetic sensor 1 of the present embodiment is briefly described. 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 the 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.

[0102] In the step 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 pinned layer which will later become the magnetization pinned layer 51, a free layer 53, and a gap layer 52.

[0103] Next, the magnetization direction of the initial magnetization fixed layer is fixed to the above-mentioned predetermined direction using laser light and an external magnetic field in a predetermined direction. For example, laser light is irradiated while applying an external magnetic field in the -X direction to the plurality of initial stacked films that will later become the plurality of stacked films 50 of the MR element 11. When the laser light irradiation is completed, the magnetization direction of the initial magnetization fixed layer is fixed to the -X direction. As a result, the initial magnetization fixed layer becomes the magnetization fixed layer 51, and the plurality of initial stacked films become the plurality of stacked films 50 of the MR element 11.

[0104] Furthermore, by setting the direction of the external magnetic field to the X direction, the magnetization direction of the initial magnetization fixed layer of each of the other plurality of initial stacked films that will later become the plurality of stacked films 50 of the MR element 12 can be fixed to the X direction. In this way, the plurality of stacked films 50 of the MR element 12 are formed.

[0105] Next, the functions and effects of the magnetic sensor device 2 and the magnetic sensor system 100 of this embodiment are described. In this embodiment, both the angle detection value θs and the intensity detection 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. Fig.10 As shown, within a specified range where the intensity Hx of the magnetic field component MFx is greater than the value Hx2 and less than the value Hx1, the intensity Hx of the magnetic field component MFx can be uniquely determined based on the magnitude Mx of the magnetization of the free layer 53 as a whole. The magnitude Mx of the magnetization of the free layer 53 as a whole 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.

[0106] In addition, the resistance value of the stacked film 50 in the MR elements 11a and 12a corresponds to the first detection signal S1. The resistance value of the stacked film 50 in the MR elements 11b and 12b corresponds to the second detection signal S2. The resistance value of the stacked 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 identified based on the first to third detection signals S1 to S3.

[0107] In addition, when the intensity Hx of the magnetic field component MFx changes periodically, within a specified range where the intensity Hx of the magnetic field component MFx is greater than the value Hx2 and smaller than the value Hx1, the magnitude Mx of the magnetization of the free layer 53 as a whole changes periodically. Therefore, when the intensity Hx of the magnetic field component MFx changes periodically, the first to third detection signals S1 to S3 also change periodically. In addition, in the present embodiment, the phase of the periodic component of the first detection signal S1, the phase of the periodic component of the second detection signal S2, and the phase of the periodic component of the third detection signal S3 are different from each other. Therefore, according to the present embodiment, the angle detection value θs can be generated based on the first to third detection signals S1 to S3.

[0108] Next, the first and second examples of the first to third detection signals S1 to S3 and the intensity detection value Va in the present 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 of the first example. Fig.11 In FIG. 1 , 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. Fig.11 In the figure, the curve marked with a symbol 71 represents the first detection signal S1, the curve marked with a symbol 72 represents the second detection signal S2, and the curve marked with a symbol 73 represents the third detection signal S3. Fig.11 The first to third detection signals S1 to S3 are shown when the value of the magnetic flux density corresponding to the target magnetic field MF is 20 mT.

[0109] Fig.12 : is a waveform diagram showing the waveforms of the first and second angle calculation signals Sd1 and Sd2, respectively, of the first example. Fig.12 In FIG. 1 , 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. Fig.12 In FIG. 1 , the curve denoted by the symbol 74 represents the first angle calculation signal Sd1 , and the curve denoted by the symbol 75 represents the second angle calculation signal Sd2 . Fig.12 Indicates the use Fig.11 The first to third detection signals S1 to S3 and equations (1) to (3) are used to generate first to third signals Sa to Sc, and the first and second angle calculation signals Sd1 and Sd2 are generated using the first to third signals Sa to Sc. Fig.12 As shown, the phase difference between the first angle calculation signal Sd1 and the second angle calculation signal Sd2 is 90°. Therefore, as described above, the angle detection value θs can be generated by using the first and second angle calculation signals Sd1 and Sd2 and equation (4).

[0110] Fig.13: is a characteristic diagram showing the intensity detection value Va of the first example. Fig.13 In FIG. 5 , the horizontal axis represents the rotation angle θM, and the vertical axis represents the intensity detection value Va. Fig.13 Indicates the use Fig.11 The first to third detection signals S1 to S3 shown in FIG. 4 and the intensity detection value Va generated by equation (4) are as follows. Fig.13 As shown, in an environment where the intensity of the target magnetic field MF is constant, the value of the intensity detection value Va is constant. Fig.13 The unit of the intensity detection value Va is mV. The processor 40 can also Fig.13 The intensity detection value Va shown is multiplied 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.

[0111] Next, the 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. Fig.14 The horizontal and vertical axes in Fig.11 The same. In addition, Fig.14 , the curve marked with a symbol 81 represents the first detection signal S1, the curve marked with a symbol 82 represents the second detection signal S2, and the curve marked with a symbol 83 represents the third detection signal S3. Fig.14 The first to third detection signals S1 to S3 are shown when the value of the magnetic flux density corresponding to the target magnetic field MF is 40 mT. Fig.11 and Fig.14 It can be understood that the amplitude of each of the first to third detection signals S1 to S3 changes according to the change in the intensity of the target magnetic field MF.

[0112] Fig.15 : is a waveform diagram showing the waveforms of the first and second angle calculation signals Sd1 and Sd2, respectively, in the second example. Fig.15 The horizontal and vertical axes in Fig.12 The same. In addition, Fig.15 In FIG. 8 , the curve marked with a symbol 84 represents the first angle calculation signal Sd1 , and the curve marked with a symbol 85 represents the second angle calculation signal Sd2 . Fig.15 Indicates the use Fig.14 The first to third detection signals S1 to S3 and equations (1) to (3) are used to generate first to third signals Sa to Sc, and the first and second angle calculation signals Sd1 and Sd2 are generated using the first to third signals Sa to Sc. Fig.15 As shown in FIG. 1 , in the second example, the amplitudes of the first and second angle calculation signals Sd1 and Sd2 are larger than those in the first example. Fig.15As shown, the phase difference between the first angle calculation signal Sd1 and the second angle calculation signal Sd2 is 90°. Therefore, similarly to the first example, the angle detection value θs can be generated by using the first and second angle calculation signals Sd1 and Sd2 and equation (4).

[0113] Fig.16 3 is a characteristic diagram showing the intensity detection value Va of the second example. Fig.16 The horizontal and vertical axes in Fig.13 same. Fig.16 Indicates the use Fig.14 The first to third detection signals S1 to S3 shown in FIG. 4 and the intensity detection value Va generated by equation (4) are as follows. Fig.13 and Fig.16 It can be understood that the value of the intensity detection value Va changes according to the change in the intensity of the target magnetic field MF.

[0114] [Second Embodiment]

[0115] Next, refer to Fig.17 The configuration of a magnetic sensor system according to a second embodiment of the present invention will be described. Fig.17 It is a perspective view showing the magnetic sensor system according to the present embodiment.

[0116] In the present embodiment, the magnetic sensor 1 is configured to detect the object magnetic field MF at the reference position PR on the reference axis C. The first detection circuit 10a of the magnetic sensor 1 is configured to detect the object 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 object 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 object magnetic field MF at the reference position PR and generate a third detection signal S3.

[0117] The first to third detection circuits 10a to 10c are respectively arranged at positions capable of detecting the object magnetic field MF at the reference position PR. For example, the first to third detection circuits 10a to 10c can all be arranged on the reference axis C. That is, the positions at which the first to third detection circuits 10a to 10c are respectively arranged can also be positions on the reference axis C. In this case, the first to third detection circuits 10a to 10c can also be stacked in any order. Alternatively, as long as the condition of detecting the object magnetic field MF at the reference position PR is met, the first to third detection circuits 10a to 10c can also be arranged on the upper surface of the support body perpendicular to the reference axis C.

[0118] The configurations of the first to third detection circuits 10a to 10c are the same as those of the first embodiment. In particular, the directions of the magnetization 51m of the magnetization fixed layers 51 of the MR elements 11a to 11c and 12a to 12c are the same as those of the first embodiment. Figure 4 The directions are the same.

[0119] The other structures, functions and effects of this embodiment are the same as those of the first embodiment.

[0120] [Third Embodiment]

[0121] Next, refer to Fig.18 A magnetic sensor device according to a third embodiment of the present invention will be described. Fig.18 : is a circuit diagram showing the structure of the magnetic sensor device according to this embodiment.

[0122] The magnetic sensor device 2 of this embodiment does not include the differential detectors 31, 32, and 33 of the first embodiment. In addition, 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. The first and second detection circuits 110a and 110b can each have a chip form or a package form sealed by a sealing resin, similarly to the first to third detection circuits 10a to 10c.

[0123] The first detection circuit 110a is configured to detect the target magnetic field MF at a first position, and to generate a first detection signal S11 that periodically changes in accordance with the periodic changes of the target magnetic field MF and whose amplitude changes according to the 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 to generate a second detection signal S12 that periodically changes in accordance with the periodic changes of the target magnetic field MF and whose amplitude changes according to the changes in the intensity of the target magnetic field MF. The first and second positions may be separated from the reference axis C (refer to the positions where the first to third detection circuits 10a to 10c are arranged in the first embodiment) in the same manner. Figure 1 ) may be located at the reference axis C (see Fig.17 ) on the .

[0124] 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 with the reference axis C as the center. The predetermined angle is equivalent to an odd multiple of 90° in electrical angle. In the present embodiment, the angle equivalent to an odd multiple of 90° in electrical angle is also physically an odd multiple of 90° in electrical angle.

[0125] The first detection circuit 110a includes two MR elements 111a and 112a, a power port V11, a ground port G11, and an output port E11. The MR element 111a is arranged between the power port V11 and the output port E11 in terms of circuit structure. The MR element 112a is arranged between the ground port G11 and the output port E11 in terms of circuit structure. A voltage or current of a predetermined magnitude is applied to the power port V11. The ground port G11 is grounded.

[0126] The second detection circuit 110b includes two MR elements 111b and 112b, a power port V12, a ground port G12, and an output port E12. The MR element 111b is arranged between the power port V12 and the output port E12 in terms of circuit structure. The MR element 112b is arranged between the ground port G12 and the output port E12 in terms of circuit structure. A voltage or current of a predetermined magnitude is applied to the power port V12. The ground port G12 is grounded.

[0127] The structure of the MR elements 111a and 111b is the same as that of the MR element 11 of the first embodiment. The structure of the MR elements 112a and 112b is the same as that of the MR element 12 of the first embodiment.

[0128] Here, if Fig.18 As shown, the DR1 direction, DR2 direction, and Z direction are defined. The DR1 direction, DR2 direction, and Z direction are orthogonal to each other. In addition, the direction opposite to the DR1 direction is referred to as the -DR1 direction, the direction opposite to the DR2 direction is referred to as the -DR2 direction, and the direction opposite to the Z direction is referred to as the -Z direction. Fig.18 The orthogonal coordinate system defined by the DR1 direction, the DR2 direction, and the Z direction is the reference coordinate system of this embodiment. Figure 1 , Figure 2 and Fig.17 The Z direction of the reference coordinate system defined by the reference axis C shown is consistent.

[0129] exist Fig.18 In the figure, each of the stacked films 50 is schematically shown as a figure representing the MR elements 111a, 111b, 112a, and 112b. The arrows drawn in the stacked film 50 indicate the direction of the magnetization 51m of the magnetization fixed layer 51 of the stacked film 50. In the first detection circuit 110a, the magnetization 51m of the magnetization fixed layer 51 in the MR element 111a includes a component in the -DR2 direction, and the magnetization 51m of the magnetization fixed layer 51 in the MR element 112a includes a component in the DR2 direction. 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.

[0130] In this embodiment, the first detection circuit 110a and the second detection circuit 110b are formed by substantially the same circuit structure. The second detection circuit 110b is equivalent to the first detection circuit 110a rotated 90 degrees around an axis (reference axis C) extending in a direction parallel to the Z direction.

[0131] 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 element 111a and the MR element 112a as the 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 element 111b and the MR element 112b as the second detection signal S12.

[0132] Next, refer to Fig.18 The method for generating the angle detection value θs and the intensity detection value Va of the present embodiment is described. In the present embodiment, the phase difference between the periodic component of the first detection signal S11 and the periodic component of the second detection signal S12 may also be an odd multiple of 1 / 4 of the period of the periodic component. In the present embodiment, in particular, the phase of the periodic component of the second detection signal S12 differs by 90° relative to the phase of the periodic component of the first detection signal S11.

[0133] The processor 40 may be 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 a range of 0° to 360° using, for example, the following equation (6).

[0134] θs=atan(S12 / S11)…(6)

[0135] In addition, the processor 40 may be configured to use the square sum of the first and second detection signals S11 and S12 to generate the intensity detection value Va. The processor 40 may also set the square sum of the first and second detection signals S11 and S12 as the intensity detection value Va. Alternatively, the processor 40 may calculate Va using the following formula (7).

[0136]

[0137] The other structures, functions and effects of this embodiment are the same as those of the first or second embodiment.

[0138] [Fourth Embodiment]

[0139] Next, refer to Fig.19 A magnetic sensor device according to a fourth embodiment of the present invention will be described. Fig.19: is a circuit diagram showing the structure of the magnetic sensor device according to this embodiment.

[0140] In this embodiment, the first detection circuit 110a and the second detection circuit 110b are composed of circuits with different structures. The structure of the first detection circuit 110a is the same as that of the third embodiment. The second detection circuit 110b is configured in 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.

[0141] The other structures, functions and effects of this embodiment are the same as those of the third embodiment.

[0142] [Fifth Embodiment]

[0143] Next, refer to Fig. 20 A motion detection device according to a fifth embodiment of the present invention will be described. Fig. 20 It is a perspective view showing the motion detection device according to this embodiment.

[0144] The motion detection device 200 of this embodiment includes a component 201 and a main body 202 that stores at least a part of the component 201. The component 201 is configured to rotate in an axial direction D1 around a reference axis C as a center, and to move in a direction D2 parallel to the reference axis C. The component 201 may also be a component such as a knob that is operated by a person. As the motion detection device 200 having such a component 201, for example, there are operating devices for automobile air conditioning or car navigation, operating devices for digital cameras or radios, and handles for smart watches. Alternatively, the component 201 may also be a component that operates in conjunction with an arbitrary driving device.

[0145] The motion detection device 200 further includes a magnetic sensor device (not shown) and a magnetic field generator (not shown). The structure of the magnetic sensor device is the same as the structure of the magnetic sensor device 2 in any one of the first to fourth embodiments. In addition, the structure of the magnetic field generator is the same as the structure of the magnetic field generator 5 in any one of the first to fourth embodiments.

[0146] The magnetic field generator is configured to operate in conjunction with the component 201. The rotational position of the magnetic field generator in the axial direction D1 corresponds to the rotational position of the component 201 in the axial direction D1. In addition, the position of the magnetic field generator in the direction D2 corresponds to the position of the component 201 in the direction D2.

[0147] As described in the first embodiment, the angle detection value generated by the magnetic sensor device has a corresponding relationship with the rotational position of the magnetic field generator. The intensity detection value generated by the magnetic sensor device has a corresponding relationship with the position in the direction D2 of the magnetic field generator. Therefore, according to the present embodiment, it is possible to detect both the rotational position of the component 201 and the position in the direction D2 of the component 201 based on the angle detection value and the intensity detection value generated by the magnetic sensor device. The rotational position of the component 201 can be calculated, for example, using the angle detection value and the number of revolutions of the component 201 counted from the angle detection value (the number of revolutions of the magnetic field generator). The position in the direction D2 of the component 201 can be calculated, for example, by multiplying the intensity detection value by a prescribed coefficient.

[0148] The other structures, functions and effects of this embodiment are the same as those of any one of the first to fourth embodiments.

[0149] In addition, the present invention is not limited to the above-described embodiments, and various modifications are possible. For example, each of the first to third detection circuits 10a to 10c may include a full-bridge circuit composed of four MR elements.

[0150] As described above, the magnetic sensor device of the present invention comprises: a magnetic sensor configured to detect an object magnetic field, and a processor. The magnetic sensor includes a plurality of detection circuits each including a magnetoresistive effect element. The magnetoresistive effect element includes: a magnetization fixed layer having magnetization whose direction is fixed, and a free layer having a magnetic eddy current structure and configured such that the center of the magnetic eddy current structure moves according to the object magnetic field. The plurality of detection circuits are configured to respectively generate a plurality of detection signals that periodically change according to the periodic change of the direction of the object magnetic field and whose amplitude changes according to the change of the intensity of the object magnetic field. The processor is configured to generate an angle detection value corresponding to the angle formed by the direction of the object magnetic field relative to the reference direction, and an intensity detection value corresponding to the intensity of the object magnetic field based on the plurality of detection signals.

[0151] In the magnetic sensor device of the present invention, the multiple detection circuits may also be a first detection circuit and a second detection circuit. The multiple detection signals may also be a first detection signal generated by a first detection circuit and a second detection signal generated by a second detection circuit. The processor may also be configured to generate an angle detection value using the ratio of the second detection signal to the first detection signal. The first detection signal and the second detection signal may also respectively include periodic components that vary with equal periods. The phase difference between the periodic component of the first detection signal and the periodic component of the second detection signal may also be an odd multiple of 1 / 4 of the period. The processor may also be configured to generate an intensity detection value using the sum of the squares of the first detection signal and the second detection signal.

[0152] In addition, in the magnetic sensor device of the present invention, the plurality of detection circuits may also be a first detection circuit, a second detection circuit, and a third detection circuit. The plurality of detection signals may also 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 also be configured to generate an angle detection value using a first signal equivalent to the difference between the first detection signal and the second detection signal, a second signal equivalent to the difference between the second detection signal and the third detection signal, and a third signal equivalent to the 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 also respectively include periodic components that vary in 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 phase difference between the periodic component of the second detection signal and the periodic component of the third detection signal may both 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 also be 2 / 3 of the period. In addition, in the magnetic sensor device of the present invention, the processor may also be configured to generate an intensity detection value using the sum of the squares of the first signal, the second signal, and the third signal.

[0153] Furthermore, in the magnetic sensor device of the present invention, the free layer may not be saturated within a range in which the intensity of the target magnetic field applied to the magnetoresistive element varies.

[0154] The magnetic sensor system of the present invention includes the magnetic sensor device of the present invention and a magnetic field generator configured to generate a target magnetic field.

[0155] In the magnetic sensor system of the present invention, the magnetic sensor and the magnetic field generator may also be configured such that when at least one of the magnetic sensor and the magnetic field generator rotates in an axial direction around 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 intensity of the target magnetic field changes. The magnetic field generator may also be configured to rotate around the reference axis and move in a direction parallel to the reference axis. The processor may also be configured to detect the rotational position of the magnetic field generator using an angle detection value, and to detect the position of the magnetic field generator in a direction parallel to the reference axis using an intensity detection value. The magnetic sensor may also be arranged in front of the moving direction of the magnetic field generator in a direction parallel to the reference axis. The target magnetic field may also include a component in a direction orthogonal to the reference axis.

[0156] The motion detection device of the present invention comprises: a component, which is configured 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, which is configured to generate a target magnetic field and is configured to operate in conjunction with the component.

[0157] It is clear from the above description that the present invention can be implemented in various forms and modifications. Therefore, within the scope of the claims and equivalents, the present invention can be implemented even in forms other than the best form described above.

Claims

1. A magnetic sensor device, characterized in that: The magnetic sensor device includes: a magnetic sensor configured to detect a magnetic field of an object, and a processor. The magnetic sensor includes a plurality of detection circuits each including a magnetoresistive effect element. The magnetoresistive element includes a fixed magnetization layer having magnetization with a fixed direction, and a free layer having a magnetic eddy current structure and configured so that the center of the magnetic eddy current structure moves according to the target magnetic field. The plurality of detection circuits are configured to respectively generate a plurality of detection signals that periodically change in accordance with periodic changes in the direction of the target magnetic field and whose amplitudes change in accordance with changes in the intensity 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 formed by the direction of the target magnetic field with respect to a reference direction and an intensity detection value corresponding to the intensity of the target magnetic field.

2. The magnetic sensor device according to claim 1, characterized in that The multiple 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, 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 magnetic sensor device according to claim 2, characterized in that The first detection signal and the second detection signal each include a periodic component that changes with a period equal to each other. A 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. The magnetic sensor device according to claim 3, characterized in that The processor is configured to generate the intensity detection value using a square sum of the first detection signal and the second detection signal.

5. The magnetic sensor device according to claim 1, characterized in that 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 processor is configured to generate the angle detection value using a first signal corresponding to the difference between the first detection signal and the second detection signal, a second signal corresponding to the difference between the second detection signal and the third detection signal, and a third signal corresponding to the difference between the third detection signal and the first detection signal.

6. The magnetic sensor device according to claim 5, characterized in that The first detection signal, the second detection signal, and the third detection signal each include a periodic component that changes with a period equal to each other. The phase difference between the periodic component of the first detection signal and the periodic component of the second detection signal, and the phase difference between the periodic component of the second detection signal and the periodic component of the third detection signal are both 1 / 3 of the period, A 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. The magnetic sensor device according to claim 5, characterized in that 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 claim 1, characterized in that The free layer is not saturated within a range in which the intensity of the target magnetic field applied to the magnetoresistive effect element varies.

9. A magnetic sensor system, characterized in that: have: The magnetic sensor device according to any one of claims 1 to 8; and The magnetic field generator is configured to generate the target magnetic field.

10. The magnetic sensor system according to claim 9, characterized in that 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 around a reference axis, the direction of the object 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 intensity of the object magnetic field changes.

11. The magnetic sensor system according to claim 10, characterized in that The magnetic field generator is configured to rotate about the reference axis and to move in a direction parallel to the reference axis. The processor is configured to detect a rotational position of the magnetic field generator using the angle detection value, and to detect a position of the magnetic field generator in a direction parallel to the reference axis using the intensity detection value.

12. The magnetic sensor system according to claim 10, characterized in that The magnetic sensor is arranged in front of the moving direction of the magnetic field generator in a direction parallel to the reference axis.

13. The magnetic sensor system according to claim 10, characterized in that The target magnetic field includes a component in a direction orthogonal to the reference axis.

14. A motion detection device, characterized in that: have: A component configured to rotate about 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 8; and The magnetic field generator is configured to generate the target magnetic field and is configured to operate in conjunction with the component.

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