Magnetic sensor, magnetic encoder, lens position detection device, and distance measuring device, and method for manufacturing magnetic sensor

Abstract

A magnetic sensor, a magnetic encoder, a lens position detection device, a distance measuring device, and a manufacturing method of a magnetic sensor are provided. In the magnetic sensor, first and second resistors are provided on a path connecting a power supply port and a first output port, and third and fourth resistors are provided on a path connecting a ground port and the first output port. In a direction parallel to an X direction, a distance between the first resistor and the second resistor and a distance between the third resistor and the fourth resistor are each λ / 2, and a distance between the first resistor and the third resistor is zero. Magnetization of a magnetization fixed layer in the first and fourth resistors includes a component in a -X direction. Magnetization of a magnetization fixed layer in the second and third resistors includes a component in an X direction.

Description

Technical Field

[0001] This invention relates to magnetic sensors, magnetic encoders, lens position detection devices, and ranging devices, as well as a method for manufacturing magnetic sensors. Background Technology

[0002] Magnetic encoders using magnetic sensors can be used to detect the position of a movable object whose position changes in a specified direction. The specified direction can be a linear direction or a rotational direction. A magnetic encoder for detecting the position of a movable object is configured such that, corresponding to the change in the position of the movable object, the relative position of a magnetic field generator, such as a magnetic scale, relative to the magnetic sensor changes within a specified range.

[0003] When the relative position of the magnetic field generator to the magnetic sensor changes, the intensity of one component of the object's magnetic field generated by the magnetic field generator and applied to the magnetic sensor changes. The magnetic sensor, for example, detects the intensity of one component of the object's magnetic field and generates two detection signals that correspond to the intensity of that component but are out of phase. Based on these two detection signals, the magnetic encoder generates a detection value that corresponds to the relative position of the magnetic field generator to the magnetic sensor.

[0004] As a magnetic sensor for use in magnetic encoders, a magnetic sensor composed of multiple magnetoresistive elements can be used. For example, International Publication No. 2009 / 031558 and International Publication No. 2009 / 119471 disclose a magnetic sensor in which multiple GMR (giant magnetoresistive) elements are arranged as magnetoresistive elements in the direction of relative movement between the magnet and the magnetic sensor and in a direction orthogonal to the direction of relative movement.

[0005] In particular, in the magnetic sensor disclosed in International Publication No. 2009 / 119471, multiple GMR elements constitute a bridge circuit for phase A and a bridge circuit for phase B. Furthermore, in this magnetic sensor, when the center-to-center distance (pitch) between the N and S poles of the magnet is λ, the multiple GMR elements are arranged with a center-to-center distance of λ, λ / 2, or λ / 4 in the relative movement direction. Output waveforms with a phase shift of λ / 2 are obtained from the bridge circuits for phase A and phase B.

[0006] Here, we consider the case where a voice coil motor is used as the driving device for a movable object. A voice coil motor consists of a magnet and a coil. When a magnetic encoder is used to detect the position of a movable object, the magnetic sensor is subjected not only to the object magnetic field (generated from a magnetic field generator for position detection) but also to a stray magnetic field generated by the magnet of the voice coil motor. During the inventors' research, it was learned that the error of a magnetic encoder depends on the strength of the component of the stray magnetic field in the same direction as the magnetic field component of the object magnetic field. Summary of the Invention

[0007] The purpose of this invention is to provide a magnetic sensor that can reduce errors caused by stray magnetic fields, as well as a magnetic encoder, a lens position detection device, and a ranging device that respectively use the magnetic sensor.

[0008] The magnetic sensor of the present invention is configured to detect the magnetic field of an object containing a magnetic field component in a first direction. The magnetic sensor of the present invention includes a first resistive element, a second resistive element, a third resistive element, and a fourth resistive element, a power supply port, a ground port, and a first output port. The first to fourth resistive elements are configured such that their resistance values ​​change with the intensity of the magnetic field component. The first and second resistive elements are sequentially arranged from the power supply port side along a first path connecting the power supply port and the first output port. The third and fourth resistive elements are sequentially arranged from the ground port side along a second path connecting the ground port and the first output port.

[0009] The interval between the first position in the first resistor and the second position in the second resistor in the first direction is an odd multiple of half the predetermined pitch. The interval between the third position in the third resistor and the fourth position in the fourth resistor in the first direction is an odd multiple of half the predetermined pitch. The interval between the first and third positions in the first direction is zero or an integer multiple of the predetermined pitch. The predetermined pitch is the length corresponding to one period of the change in the intensity of the magnetic field component, assuming that the intensity of the magnetic field component changes periodically along the first direction according to a predetermined period.

[0010] The magnetic sensor of the present invention further includes multiple magnetoresistive elements. Each magnetoresistive element includes a magnetized fixed layer, a free layer, and a gap layer disposed between the magnetized fixed layer and the free layer. The magnetized fixed layer has a first magnetization with a fixed orientation. The free layer has a second magnetization, the direction of which can vary in a plane parallel to both the first direction and a second direction orthogonal to the first direction. The magnetized fixed layer, the free layer, and the gap layer are stacked in a third direction orthogonal to the first and second directions. The first to fourth resistive elements are constructed using multiple magnetoresistive elements.

[0011] The first magnetization of the magnetization fixing layer in the first and fourth resistive elements includes a component of a first magnetization direction, wherein the first magnetization direction is a direction parallel to a first direction. The first magnetization of the magnetization fixing layer in the second and third resistive elements includes a component of a second magnetization direction opposite to the first magnetization direction.

[0012] In the magnetic sensor of the present invention, the first position can be the center of gravity of the first resistive element when viewed from a direction parallel to a third party. The second position can be the center of gravity of the second resistive element when viewed from a direction parallel to a third party. The third position can be the center of gravity of the third resistive element when viewed from a direction parallel to a third party. The fourth position can be the center of gravity of the fourth resistive element when viewed from a direction parallel to a third party.

[0013] Furthermore, in the magnetic sensor of the present invention, the first resistive element and the third resistive element can be adjacent to each other in the second direction. The second resistive element and the fourth resistive element can also be adjacent to each other in the second direction.

[0014] Furthermore, the magnetic sensor of the present invention may also include: a fifth resistor, a sixth resistor, a seventh resistor, and an eighth resistor, as well as a second output port, wherein the fifth to eighth resistors are configured such that their resistance values ​​change with the intensity of the magnetic field component. The fifth and sixth resistors may be sequentially arranged from the ground port side along a third path connecting the ground port and the second output port. The seventh and eighth resistors may be sequentially arranged from the power port side along a fourth path connecting the power supply port and the second output port.

[0015] The interval between the fifth position in the fifth resistor body and the sixth position in the sixth resistor body in the first direction can be an odd multiple of half the specified pitch. The interval between the seventh position in the seventh resistor body and the eighth position in the eighth resistor body in the first direction can be an odd multiple of half the specified pitch. The interval between the fifth and seventh positions in the first direction is zero or an integer multiple of the specified pitch. When n is an integer greater than or equal to 1, the interval between the first and fifth positions in the first direction can be (4n-3) / 4 of the specified pitch.

[0016] The fifth to eighth resistive elements can be constructed using multiple magnetoresistive elements. The first magnetization of the magnetization fixing layer in the fifth and eighth resistive elements can include a component of the second magnetization direction. The first magnetization of the magnetization fixing layer in the sixth and seventh resistive elements can include a component of the first magnetization direction.

[0017] In the case where the magnetic sensor of the present invention includes a fifth to an eighth resistive element, the fifth position can be the center of gravity of the fifth resistive element when viewed from a direction parallel to a third party. The sixth position can be the center of gravity of the sixth resistive element when viewed from a direction parallel to a third party. The seventh position can be the center of gravity of the seventh resistive element when viewed from a direction parallel to a third party. The eighth position can be the center of gravity of the eighth resistive element when viewed from a direction parallel to a third party.

[0018] Furthermore, in the case where the magnetic sensor of the present invention includes a fifth to an eighth resistive element, the fifth resistive element and the seventh resistive element may be adjacent to each other in the second direction. The sixth resistive element and the eighth resistive element may also be adjacent to each other in the second direction.

[0019] Furthermore, in the case where the magnetic sensor of the present invention includes fifth to eighth resistive elements, the first resistive element may be adjacent to the seventh resistive element but not adjacent to the eighth resistive element. The eighth resistive element may be adjacent to the second resistive element but not adjacent to the first resistive element. In this case, the third resistive element may be positioned at a location spaced apart from the seventh resistive element by the first resistive element. Additionally, the fourth resistive element may be positioned at a location spaced apart from the eighth resistive element by the second resistive element. Furthermore, the fifth resistive element may be positioned at a location spaced apart from the first resistive element by the seventh resistive element. Additionally, the sixth resistive element may be positioned at a location spaced apart from the second resistive element by the eighth resistive element.

[0020] Furthermore, in the magnetic sensor of the present invention, each of the plurality of magnetoresistive effect elements can be configured such that a bias magnetic field is applied to the free layer in a direction intersecting the first direction and the third direction.

[0021] In addition, in the magnetic sensor of the present invention, the gap layer can be a tunneling barrier layer.

[0022] The magnetic encoder of the present invention includes a magnetic sensor and a magnetic field generator for generating a magnetic field for a target. 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 is activated, the intensity of the magnetic field component at a reference position changes.

[0023] The lens position detection device of the present invention is used to detect the position of a lens whose position is variable. The lens position detection device of the present invention includes a magnetic sensor and a magnetic field generator for generating a magnetic field of the target object. The lens is configured to be movable in a first direction. The magnetic sensor and the magnetic field generator are configured such that the intensity of the magnetic field component changes when the position of the lens changes.

[0024] In the lens position detection device of the present invention, the magnetic field generator can be a magnetic ruler, wherein multiple sets of N poles and S poles are alternately arranged in the first direction.

[0025] The ranging device of the present invention measures the distance to an object by detecting the incident light. The ranging device of the present invention includes: an optical element configured to change and rotate the direction of light travel; a magnetic sensor of the present invention; and a magnetic field generator for generating a magnetic field around the object. The magnetic field generator is configured to rotate about a rotation axis in conjunction with the optical element. The intensity of the magnetic field component at a reference position changes with the rotation of the magnetic field generator.

[0026] In the ranging device of the present invention, the magnetic field generator can be a magnetic scale, wherein multiple sets of N poles and S poles are alternately arranged around a rotation axis. In this case, the magnetic field generator can have an end face located at an end in a direction parallel to the rotation axis. Multiple sets of N poles and S poles can be disposed on the end face. The magnetic sensor can be configured to face the end face. Alternatively, the magnetic field generator can also have an outer peripheral surface facing away from the rotation axis. Multiple sets of N poles and S poles can also be disposed on the outer peripheral surface. The magnetic sensor can also be configured to face the outer peripheral surface.

[0027] The method for manufacturing the magnetic sensor of the present invention includes a step of forming a plurality of magnetoresistive effect elements. The step of forming a plurality of magnetoresistive effect elements includes: a step of forming a plurality of initial magnetoresistive effect elements, wherein each initial magnetoresistive effect element comprises an initial magnetization fixing layer, a free layer and a gap layer, which will later become a magnetization fixing layer; and a step of fixing the first magnetization direction of the initial magnetization fixing layer using a laser and an external magnetic field.

[0028] In the magnetic sensor, magnetic encoder, lens position detection device, and ranging device of the present invention, the first to fourth resistive elements satisfy, as described above, the necessary conditions regarding the circuit structure configuration, the necessary conditions regarding the physical configuration, and the necessary conditions regarding the magnetization of the magnetized fixing layer. Therefore, according to the present invention, errors caused by stray magnetic fields can be reduced.

[0029] Other objects, features and benefits of the present invention will become sufficiently clear from the following description. Attached Figure Description

[0030] Figure 1 This is a perspective view of a magnetic encoder according to a first embodiment of the present invention.

[0031] Figure 2 This is a front view of the magnetic encoder according to the first embodiment of the present invention.

[0032] Figure 3 This is a plan view showing the magnetic sensor according to the first embodiment of the present invention.

[0033] Figure 4 This is a circuit diagram showing the structure of the magnetic sensor according to the first embodiment of the present invention.

[0034] Figure 5This is an explanatory diagram illustrating the configuration of the first to eighth resistors in the first embodiment of the present invention.

[0035] Figure 6 This is a plan view showing the first resistor in the first embodiment of the present invention.

[0036] Figure 7 This is a perspective view showing a first example of a magnetoresistive effect element in the first embodiment of the present invention.

[0037] Figure 8 This is a perspective view showing a second example of a magnetoresistive effect element in the first embodiment of the present invention.

[0038] Figure 9 This is a plan view showing the magnetic sensor of the comparative example.

[0039] Figure 10 This is a circuit diagram showing the structure of the magnetic sensor in the comparative example.

[0040] Figure 11 This is a characteristic plot showing the Vpp and error of the comparative example model obtained through the first simulation.

[0041] Figure 12 This is a characteristic plot showing the Vpp and error of the model of the embodiment obtained through the first simulation.

[0042] Figure 13 This is a characteristic plot showing the Vpp and error of the comparative example model obtained through the second simulation.

[0043] Figure 14 This is a characteristic graph showing the Vpp and error of the model of the embodiment obtained through the second simulation.

[0044] Figure 15 This is a perspective view showing a lens module including the position detection device according to the second embodiment of the present invention.

[0045] Figure 16 This is a perspective view showing the position detection device according to the second embodiment of the present invention.

[0046] Figure 17 This is a perspective view showing the distance measuring device according to the third embodiment of the present invention.

[0047] Figure 18 This is a perspective view showing a first example of a magnetic field generator for a ranging device according to the third embodiment of the present invention.

[0048] Figure 19 This is a plan view showing a first example of a magnetic field generator for a ranging device according to the third embodiment of the present invention.

[0049] Figure 20 This is a perspective view showing a second example of a magnetic field generator for a ranging device according to the third embodiment of the present invention.

[0050] Figure 21 This is a plan view showing the magnetic sensor according to the fourth embodiment of the present invention.

[0051] Figure 22 This is a circuit diagram showing the structure of the magnetic sensor according to the fourth embodiment of the present invention. Detailed Implementation

[0052] [First Implementation Method]

[0053] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. First, referring to... Figure 1 and Figure 2 The general structure of the magnetic encoder according to the first embodiment of the present invention will be described. Figure 1 This is a three-dimensional view of magnetic encoder 1. Figure 2 This is a front view showing the magnetic encoder 1. The magnetic encoder 1 of this embodiment includes a magnetic sensor 2 and a magnetic field generator 3.

[0054] The magnetic field generator 3 is a magnetic field used for position detection, generating the magnetic field to be detected by the magnetic sensor 2 (the detection target magnetic field), i.e., the target magnetic field MF. The target magnetic field MF includes a magnetic field component in a direction parallel to a virtual straight line. The magnetic sensor 2 and the magnetic field generator 3 are configured such that when at least one of the magnetic sensor 2 and the magnetic field generator 3 is activated, the intensity of the magnetic field component at the reference position changes. The reference position can be the location where the magnetic sensor 2 is installed. The magnetic sensor 2 detects the target magnetic field MF containing the aforementioned magnetic field component and generates at least one detection signal corresponding to the intensity of the magnetic field component.

[0055] As for the operation modes of the magnetic sensor 2 and the magnetic field generator 3, there is a first mode in which at least one of the magnetic sensor 2 and the magnetic field generator 3 moves, and a second mode in which at least one of the magnetic sensor 2 and the magnetic field generator 3 rotates. In the first mode, the relative position of the magnetic field generator 3 with respect to the magnetic sensor 2 changes, while in the second mode, the relative position of the magnetic field generator 3 with respect to the magnetic sensor 2 may remain unchanged.

[0056] The magnetic field generator 3 can be a magnetic scale with multiple sets of N poles and S poles alternately arranged in a specified direction. The magnetic scale can be obtained by alternately magnetizing multiple sets of N poles and S poles on a magnetic medium such as magnetic tape, or by arranging multiple magnets along the specified direction. The specified direction can be a linear direction or a rotational direction. When the specified direction is a linear direction, the magnetic sensor 2 or the magnetic field generator 3 can move within a specified range along the linear direction. When the specified direction is a rotational direction, the magnetic sensor 2 or the magnetic field generator 3 can rotate within a specified range along the rotational direction.

[0057] In this embodiment, the magnetic field generator 3 is a linear magnetic ruler obtained by magnetizing multiple sets of N and S poles in a straight direction. The magnetic sensor 2 or the magnetic field generator 3 can move along the length of the magnetic field generator 3. Figure 2 As shown, the interval between two adjacent N poles along the length of the magnetic field generator 3, that is, the interval between two adjacent N poles separated by one S pole, is called the magnetic pole interval, and the size of the magnetic pole interval is represented by the symbol Lp.

[0058] Here, as Figure 1 and Figure 2 The diagram defines the X, Y, and Z directions. In this embodiment, the direction parallel to the long side of the magnetic field generator 3 is designated as the X direction. Additionally, the two directions perpendicular to and orthogonal to the X direction are designated as the Y and Z directions. Figure 2 In the diagram, the Y direction is represented as from... Figure 2 The direction from outside the paper to inside the paper. Additionally, the direction opposite to the X direction is defined as the -X direction, the direction opposite to the Y direction as the -Y direction, and the direction opposite to the Z direction as the -Z direction.

[0059] The magnetic sensor 2 is positioned relative to the magnetic field generator 3 in the Z direction. The magnetic sensor 2 is configured to detect the strength of the magnetic field component MFx of the object's magnetic field MF at a predetermined location, in a direction parallel to the X direction. The strength of the magnetic field component MFx is represented by a positive value when its direction is the X direction, and by a negative value when its direction is the -X direction. The strength of the magnetic field component MFx changes periodically as the magnetic sensor 2 or the magnetic field generator 3 moves along a direction parallel to the X direction. The direction parallel to the X direction corresponds to the "first direction" in this invention.

[0060] Next, refer to Figure 3 and Figure 4 Detailed description of magnetic sensor 2. Figure 3 This is a plan view representing magnetic sensor 2. Figure 4 This is a circuit diagram showing the structure of magnetic sensor 2. (For example...) Figure 4As shown, the magnetic encoder 1 also includes a detection value generation circuit 4. The detection value generation circuit 4 generates a detection value Vs corresponding to the position of the magnetic sensor 2 or the magnetic field generator 3, based on at least one detection signal generated by the magnetic sensor 2 that corresponds to the strength of the magnetic field component MFx. The detection value generation circuit 4 can be implemented, for example, by an application-specific integrated circuit (ASIC) or a microcomputer.

[0061] The magnetic sensor 2 includes a first resistive element R11, a second resistive element R12, a third resistive element R13, a fourth resistive element R14, a fifth resistive element R21, a sixth resistive element R22, a seventh resistive element R23, and an eighth resistive element R24, each configured such that its resistance value varies according to the strength of the magnetic field component MFx. Furthermore, the magnetic sensor 2 includes multiple magnetoresistive elements (hereinafter referred to as MR elements) 50. Each of the first to eighth resistive elements R11–R14 and R21–R24 is constructed using multiple MR elements 50.

[0062] The magnetic sensor 2 also includes a power supply port V1, a ground port G1, a first output port E1, and a second output port E2. The ground port G1 is grounded. The first and second output ports E1 and E2 are connected to the detection value generation circuit 4. The magnetic sensor 2 can be driven by a constant voltage or a constant current. When the magnetic sensor 2 is driven by a constant voltage, a predetermined voltage is applied to the power supply port V1. When the magnetic sensor 2 is driven by a constant current, a predetermined current is supplied to the power supply port V1.

[0063] The magnetic sensor 2 generates a signal corresponding to the potential of the first output port E1 as a first detection signal S1, and generates a signal corresponding to the potential of the second output port E2 as a second detection signal S2. The detection value generation circuit 4 generates a detection value Vs based on the first and second detection signals S1 and S2. Furthermore, at least one of the magnetic sensor 2 and the detection value generation circuit 4 can be configured to correct the amplitude, phase, and offset of the first and second detection signals S1 and S2 respectively.

[0064] The first to eighth resistors R11-R14 and R21-R24 satisfy the following necessary conditions regarding the circuit structure configuration. The first resistor R11 and the second resistor R12 are sequentially arranged on the first path 5 connecting the power supply port V1 and the first output port E1, starting from the power supply port V1 side. The third resistor R13 and the fourth resistor R14 are sequentially arranged on the second path 6 connecting the ground port G1 and the first output port E1, starting from the ground port G1 side. The fifth resistor R21 and the sixth resistor R22 are sequentially arranged on the third path 7 connecting the ground port G1 and the second output port E2, starting from the ground port G1 side. The seventh resistor R23 and the eighth resistor R24 ​​are sequentially arranged on the fourth path 8 connecting the power supply port V1 and the second output port E2, starting from the power supply port V1 side.

[0065] like Figure 3 As shown, the magnetic sensor 2 also includes a substrate 10, a power supply terminal 11, a ground terminal 12, a first output terminal 13, and a second output terminal 14 disposed on the substrate 10. The power supply terminal 11 constitutes a power supply port V1. The ground terminal 12 constitutes a ground port G1. The first and second output terminals 13 and 14 constitute the first and second output ports E1 and E2, respectively.

[0066] Next, refer to Figure 5 The configuration of the first to eighth resistors R11 to R14 and R21 to R24 is explained. Figure 5 This is an explanatory diagram illustrating the arrangement of the first to eighth resistors R11-R14 and R21-R24. Here, the specified pitch λ is defined as follows: Pitch λ is the length corresponding to one period of the change in the intensity of the magnetic field component MFx, assuming that the intensity of the magnetic field component MFx changes periodically along a direction parallel to the X direction according to a specified period.

[0067] When using a specific magnetic field generator containing multiple sets of N and S poles, the pitch λ is essentially equal to the interval between two adjacent N poles separated by one S pole. A specific magnetic field generator can be... Figure 2 The magnetic field generator 3 is shown. In this case, the pitch λ is equal to... Figure 2 The magnetic pole spacing Lp is shown. Alternatively, a specific magnetic field generator can also be a magnetic field generator with a magnetic pole spacing different from that of magnetic field generator 3. In this case, the pitch λ is a different size from the magnetic pole spacing Lp. The following explanation will take the case where the specific magnetic field generator is magnetic field generator 3, that is, the case where the pitch λ is equal to the magnetic pole spacing Lp, as an example.

[0068] exist Figure 5In the attached figures, reference numeral C11 indicates the first position within the first resistor R11, reference numeral C12 indicates the second position within the second resistor R12, reference numeral C13 indicates the third position within the third resistor R13, and reference numeral C14 indicates the fourth position within the fourth resistor R14. The first to fourth positions C11 to C14 are used to determine the physical positions of the first to fourth resistors R11 to R14. In this embodiment, in particular, the first position C11 is the center of gravity of the first resistor R11 when viewed from the Z direction, the second position C12 is the center of gravity of the second resistor R12 when viewed from the Z direction, the third position C13 is the center of gravity of the third resistor R13 when viewed from the Z direction, and the fourth position C14 is the center of gravity of the fourth resistor R14 when viewed from the Z direction.

[0069] In addition, Figure 5 In the attached figures, reference numeral C21 indicates the fifth position within the fifth resistor R21, reference numeral C22 indicates the sixth position within the sixth resistor R22, reference numeral C23 indicates the seventh position within the seventh resistor R23, and reference numeral C24 indicates the eighth position within the eighth resistor R24. The fifth to eighth positions C21 to C24 are used to determine the physical positions of the fifth to eighth resistors R21 to R24. In this embodiment, in particular, the fifth position C21 is the center of gravity of the fifth resistor R21 when viewed from the Z direction, the sixth position C22 is the center of gravity of the sixth resistor R22 when viewed from the Z direction, the seventh position C23 is the center of gravity of the seventh resistor R23 when viewed from the Z direction, and the eighth position C24 is the center of gravity of the eighth resistor R24 ​​when viewed from the Z direction.

[0070] The first to eighth resistors R11–R14 and R21–R24 satisfy the following necessary conditions regarding their physical configuration: The distance between the first position C11 and the second position C12 in a direction parallel to the X-direction is an odd multiple of half the pitch λ. The distance between the third position C13 and the fourth position C14 in a direction parallel to the X-direction is an odd multiple of half the pitch λ. The distance between the first position C11 and the third position C13 in a direction parallel to the X-direction is zero or an integer multiple of the pitch λ.

[0071] The interval between the fifth position C21 and the sixth position C22 in a direction parallel to the X direction is an odd multiple of half the pitch λ. The interval between the seventh position C23 and the eighth position C24 in a direction parallel to the X direction is an odd multiple of half the pitch λ. The interval between the fifth position C21 and the seventh position C23 in a direction parallel to the X direction is zero or an integer multiple of the pitch λ. The interval between the first position C11 and the fifth position C21 in a direction parallel to the X direction is (4n-3) / 4 of the pitch λ. Here, n is an integer greater than or equal to 1.

[0072] In this embodiment, the second position C12 is located λ / 2 away from the first position C11 in the X direction, and the fourth position C14 is located λ / 2 away from the third position C13 in the X direction. Furthermore, the interval between the first position C11 and the third position C13 in a direction parallel to the X direction is zero. That is, the third position C13 in a direction parallel to the X direction is the same as the first position C11 in that direction. The third position C13 is located ahead of the first position C11 in the -Y direction. Similarly, the fourth position C14 in a direction parallel to the X direction is the same as the second position C12 in that direction. The fourth position C14 is located ahead of the second position C12 in the -Y direction.

[0073] The fifth to eighth resistors R21 to R24 are positioned in front of the first to fourth resistors R11 to R14 in the Y direction. The physical configuration of the fifth to eighth resistors R21 to R24 is the same as that of the first to fourth resistors R11 to R14. By replacing the first to fourth resistors R11 to R14 and the first to fourth positions C11 to C14 in the description of the physical configuration of the first to fourth resistors R11 to R14 with the fifth to eighth resistors R21 to R24 and the fifth to eighth positions C21 to C24, respectively, we obtain the description of the physical configuration of the fifth to eighth resistors R21 to R24.

[0074] Furthermore, in this embodiment, the fifth position C21 (seventh position C23) is located λ / 4 ahead of the first position C11 (third position C13) in the X direction. The sixth position C22 (eighth position C24) is located λ / 4 ahead of the second position C12 (fourth position C14) in the X direction.

[0075] The first resistor R11 is adjacent to the seventh resistor R23 but not adjacent to the eighth resistor R24. The eighth resistor R24 ​​is adjacent to the second resistor R12 but not adjacent to the first resistor R11.

[0076] The third resistor R13 is positioned between the seventh resistor R23 and the first resistor R11. The fourth resistor R14 is positioned between the eighth resistor R24 ​​and the second resistor R12. The fifth resistor R21 is positioned between the first resistor R11 and the seventh resistor R23. The sixth resistor R22 is positioned between the second resistor R12 and the eighth resistor R24.

[0077] Next, the structure of the first to eighth resistors R11-R14 and R21-R24 will be described. The first and second detection signals S1 and S2 each contain an ideal component that changes periodically according to a predetermined signal period in a manner that depicts an ideal sine curve (including a sine waveform and a cosine waveform). In this embodiment, the first to eighth resistors R11-R14 and R21-R24 are configured such that the phase of the ideal component of the first detection signal S1 is different from the phase of the ideal component of the second detection signal S2. Figure 2 The magnetic pole spacing Lp and shown Figure 5 The pitch λ shown corresponds to one period in the ideal composition, which is 360° of electrical angle.

[0078] In addition to the ideal component, the first and second detection signals S1 and S2 each contain multiple higher harmonic components that are equivalent to the higher harmonics of the ideal component. In this embodiment, the first to eighth resistors R11 to R14 and R21 to R24 are configured to reduce the multiple higher harmonic components.

[0079] The structures of the first to eighth resistors R11-R14 and R21-R24 will be described in detail below. First, the structure of the MR element 50 will be described. In this embodiment, the MR element 50 is a spin valve type MR element. This spin valve type MR element includes a magnetized fixed layer, a free layer, and a gap layer disposed between the magnetized fixed layer and the free layer. The magnetized fixed layer has a first magnetization with a fixed direction. The free layer has a second magnetization with a direction that can vary in a plane (in the XY plane), wherein the plane is parallel to both the direction parallel to the X direction and the direction parallel to the Y direction. The magnetized fixed layer, the free layer, and the gap layer are stacked in a direction parallel to the Z direction. The direction parallel to the Y direction corresponds to the "second direction" in this invention. The direction parallel to the Z direction corresponds to the "third direction" in this invention.

[0080] The spin-valve type MR element can be either a TMR (tunneling magnetoresistance) element or a GMR (giant magnetoresistance) element. In this embodiment, especially to reduce the size of the magnetic sensor 2, the MR element 50 is preferably a TMR element. In a TMR element, the gap layer is a tunneling barrier layer. In a GMR element, the gap layer is a non-magnetic conductive layer. In the spin-valve type MR element, the resistance value varies depending on the angle between the magnetization direction of the free layer and the magnetization direction of the magnetized fixed layer, with the resistance value being the minimum at 0° and the resistance value being the maximum at 180°.

[0081] exist Figure 3 and Figure 4In the diagram, the arrows depicted within the first to eighth resistors R11~R14 and R21~R24 indicate the direction of the first magnetization of the magnetization fixation layer of each of the multiple MR elements 50 contained in the resistor.

[0082] The first to eighth resistors R11-R14 and R21-R24 satisfy the following necessary conditions regarding the magnetization of the magnetization fixing layer. The first magnetization of the magnetization fixing layer in the first and fourth resistors R11 and R14 includes a component of a first magnetization direction, which is a direction parallel to the aforementioned first direction (parallel to the X direction). The first magnetization of the magnetization fixing layer in the second and third resistors R12 and R13 includes a component of a second magnetization direction opposite to the first magnetization direction. The first magnetization of the magnetization fixing layer in the fifth and eighth resistors R21 and R24 includes a component of the second magnetization direction. The first magnetization of the magnetization fixing layer in the sixth and seventh resistors R22 and R23 includes a component of the first magnetization direction. In this embodiment, in particular, the first magnetization direction is the -X direction, and the second magnetization direction is the X direction.

[0083] Furthermore, when the first magnetization includes a component with a specific magnetization direction, this component with a specific magnetization direction may be a principal component of the first magnetization. Alternatively, the first magnetization may not include a component with a direction orthogonal to the specific magnetization direction. In this embodiment, when the first magnetization includes a component with a specific magnetization direction, the direction of the first magnetization is either the specific magnetization direction or a substantially specific magnetization direction.

[0084] The direction of the second magnetization of the free layer of each of the multiple MR elements 50 varies in the XY plane according to the strength of the magnetic field component MFx. Consequently, the potentials of the first and second output ports E1 and E2 vary according to the strength of the magnetic field component MFx.

[0085] Next, the arrangement of the plurality of MR elements 50 in each of the first to eighth resistors R11-R14 and R21-R24 will be described. Here, a collection of one or more MR elements 50 is referred to as an element group. Each of the first to eighth resistors R11-R14 and R21-R24 includes a plurality of element groups. The plurality of element groups are arranged at predetermined intervals based on the pitch λ in a manner that reduces error components. Furthermore, in the following description, when describing the arrangement of the plurality of element groups, the description is based on a predetermined position of the element group. The predetermined position is, for example, the center of gravity of the element group when viewed from the Z direction.

[0086] Figure 6 This is a planar diagram representing the first resistive element R11. (Example) Figure 6As shown, the first resistor R11 includes eight element groups 31, 32, 33, 34, 35, 36, 37, and 38. Each element group 31 to 38 is divided into four partitions. Each partition contains one or more MR elements 50. Therefore, each element group includes four or more MR elements 50. Multiple MR elements 50 can be connected in series within each element group. In this case, multiple element groups can also be connected in series. Alternatively, multiple MR elements 50 can be connected in series independently of element groups.

[0087] exist Figure 6 In this configuration, element groups 31-38 are configured to reduce high-order harmonic components equivalent to the third higher harmonic (3rd order higher harmonic) of the ideal component, the fifth higher harmonic (5th order higher harmonic) of the ideal component, and the seventh higher harmonic (7th order higher harmonic) of the ideal component. For example... Figure 6 As shown, component groups 31 to 34 are arranged along the X direction. Component group 32 is arranged at a position relative to component group 31 in the X direction, away from λ / 10. Component group 33 is arranged at a position relative to component group 31 in the X direction, away from λ / 6. Component group 34 is arranged at a position relative to component group 31 in the X direction, away from λ / 10 + λ / 6 (relative to component group 32 in the X direction, away from λ / 6).

[0088] In addition, such as Figure 6 As shown, component groups 35-38 are arranged in front of component groups 31-34 in the -Y direction along the X direction. Component group 35 is arranged at a position relative to component group 31 in the X direction away from λ / 14. Component group 36 is arranged at a position relative to component group 31 in the X direction away from λ / 14+λ / 10 (relative to component group 32 in the X direction away from λ / 14). Component group 37 is arranged at a position relative to component group 31 in the X direction away from λ / 14+λ / 6 (relative to component group 33 in the X direction away from λ / 14). Component group 38 is arranged at a position relative to component group 31 in the X direction away from λ / 14+λ / 10+λ / 6 (relative to component group 34 in the X direction away from λ / 14).

[0089] The configuration of multiple component groups for reducing multiple higher harmonic components is not limited to Figure 6The example shown is illustrated here. Let k and m be integers greater than 1 and distinct from each other. For instance, to reduce a higher harmonic component corresponding to the 2k+1th order harmonic, the first element group is positioned at a position λ / (4k+2) away from the second element group in the X direction. Furthermore, to reduce a higher harmonic component corresponding to the 2m+1st order harmonic, the third element group is positioned at a position λ / (4m+2) away from the first element group in the X direction, and the fourth element group is positioned at a position λ / (4m+2) away from the second element group in the X direction. In this way, to reduce higher harmonic components corresponding to multiple higher harmonics, each of the multiple element groups used to reduce a higher harmonic component corresponding to one higher harmonic is positioned at a position, relative to the corresponding element group among the multiple element groups used to reduce higher harmonic components corresponding to other higher harmonics, at a predetermined interval in the X direction based on the pitch λ.

[0090] In this embodiment, the structure and arrangement of the plurality of element groups in each of the second to eighth resistors R12-R14 and R21-R24 are the same as the structure and arrangement of the plurality of element groups in the first resistor R11. That is, each of the second to eighth resistors R12-R14 and R21-R24 includes Figure 6 The structure and positional relationship of the eight component groups 31 to 38 are shown. Furthermore, component group 31 of the third resistor R13 is positioned in the X direction at the same location as component group 31 of the first resistor R11. Component group 31 of the fourth resistor R14 is positioned in the X direction at the same location as component group 31 of the second resistor R12. Component group 31 of the second resistor R12 is positioned at a position λ / 2 away from component group 31 of the first resistor R11 in the X direction. Component group 31 of the fourth resistor R14 is positioned at a position λ / 2 away from component group 31 of the third resistor R13 in the X direction.

[0091] The element group 31 of the seventh resistor R23 is positioned in the X direction at the same location as the element group 31 of the fifth resistor R21. The element group 31 of the eighth resistor R24 ​​is positioned in the X direction at the same location as the element group 31 of the sixth resistor R22. The element group 31 of the fifth resistor R21 is positioned at a distance of λ / 4 in the X direction relative to the element group 31 of the first resistor R11. The element group 31 of the sixth resistor R22 is positioned at a distance of λ / 2 in the X direction relative to the element group 31 of the fifth resistor R21. The element group 31 of the eighth resistor R24 ​​is positioned at a distance of λ / 2 in the X direction relative to the element group 31 of the seventh resistor R23.

[0092] With the structure of the first to eighth resistors R11 to R14 and R21 to R24 described above, the phase difference between the ideal component of the second detection signal S2 and the ideal component of the first detection signal S1 becomes an odd multiple of 1 / 4 of the specified signal period (the signal period of the ideal component), and the multiple higher harmonic components of the first and second detection signals S1 and S2 are reduced respectively.

[0093] Furthermore, from the perspective of manufacturing precision of MR element 50, the positions of the first to eighth resistors R11~R14, R21~R24 and the positions of element groups 31~38 can be slightly deviated from the above positions.

[0094] Next, refer to Figure 7 and Figure 8 The first and second examples of MR element 50 will be described. Figure 7 This is a perspective view showing a first example of an MR element 50. In this first example, the MR element 50 includes a laminated film 50A, which includes a magnetized fixing layer 51, a gap layer 52, and a free layer 53 sequentially stacked in the Z direction. The planar shape of the laminated film 50A viewed from the Z direction can be circular, or it can be... Figure 7 The image shown is a square or approximately a square.

[0095] The lower surface of the laminated film 50A of the MR element 50 is electrically connected to the lower surface of the laminated film 50A of other MR elements 50 via a lower electrode (not shown), and the upper surface of the laminated film 50A of the MR element 50 is electrically connected to the upper surface of the laminated film 50A of another MR element 50 via an upper electrode (not shown). Thus, multiple MR elements 50 are connected in series. Furthermore, the arrangement of layers 51 to 53 in the laminated film 50A can also be... Figure 7 The configuration shown is upside down.

[0096] The MR element 50 also includes a bias magnetic field generator 50B for generating a bias magnetic field applied to the free layer 53. The direction of the bias magnetic field is a direction intersecting a direction parallel to the X-direction. In the first example, the bias magnetic field generator 50B includes two magnets 54 and 55. Magnet 54 is positioned in front of the laminated film 50A in the -Y direction. Magnet 55 is positioned in front of the laminated film 50A in the Y direction. In the first example, in particular, the laminated film 50A and magnets 54 and 55 are positioned at a location intersecting a virtual plane parallel to the XY plane. Furthermore, in Figure 7 In the diagram, the arrows inside magnets 54 and 55 indicate the magnetization directions of magnets 54 and 55. In the first example, the direction of the bias magnetic field is the Y direction.

[0097] Figure 8This is a perspective view showing a second example of the MR element 50. The structure of the second example of the MR element 50 is the same as that of the first example, except for the planar shape of the laminated film 50A and the positions of the magnets 54 and 55. In the second example, the magnets 54 and 55 are arranged in a different position in the Z direction than those in the laminated film 50A. Figure 8 In the example shown, magnets 54 and 55 are specifically positioned in front of the laminated film 50A in the Z direction. Furthermore, the planar shape of the laminated film 50A, when viewed from the Z direction, is a rectangle that is longer in the Y direction. When viewed from the Z direction, magnets 54 and 55 are positioned at a point overlapping with the laminated film 50A.

[0098] Furthermore, the direction of the bias magnetic field and the configuration of magnets 54 and 55 are not limited to... Figure 7 and Figure 8 The example shown illustrates this. For instance, the direction of the bias magnetic field can be any direction that intersects both the direction parallel to the X direction and the direction parallel to the Z direction, and it can be a direction tilted relative to the Y direction. Additionally, magnets 54 and 55 can also be offset from each other in a direction parallel to the X direction.

[0099] Alternatively, it can replace the bias magnetic field generator 50B and apply a bias magnetic field to the free layer 53 by utilizing uniaxial magnetic anisotropy such as shape magnetic anisotropy and crystal magnetic anisotropy.

[0100] Next, the method for generating the detection value Vs in this embodiment will be described. The detection value generation circuit 4 generates the detection value Vs, for example, as follows: The detection value generation circuit 4 calculates the arctangent of the ratio of the second detection signal S2 to the first detection signal S1, i.e., atan(S2 / S1), to obtain an initial detection value within a range of 0° to less than 360°. The initial detection value can be the arctangent value itself, or it can be a value obtained by adding a predetermined angle to the arctangent value.

[0101] When the arctangent value is 0°, in the X direction, the position of the S pole of the magnetic field generator 3 coincides with the position of the element group 31 of the first and third resistors R11 and R13 respectively. Furthermore, when the arctangent value is 180°, in the X direction, the position of the N pole of the magnetic field generator 3 coincides with the position of the element group 31 of the first and third resistors R11 and R13 respectively. Therefore, the initial detection value corresponds to the relative position (hereinafter also referred to as the relative position) of the magnetic field generator 3 relative to the magnetic sensor 2 within the magnetic pole spacing Lp.

[0102] In addition, the detection value generation circuit 4 sets one cycle of the initial detection value to 360° of the electrical angle and counts the number of electrical angle rotations from the reference position. One rotation of the electrical angle corresponds to a movement of the magnetic pole spacing Lp in the relative position. Based on the initial detection value and the number of electrical angle rotations, the detection value generation circuit 4 generates a detection value Vs that corresponds to the relative position.

[0103] Next, a brief description of the manufacturing method of the magnetic sensor 2 according to this embodiment will be given. The manufacturing method of the magnetic sensor 2 includes: a process of forming a plurality of MR elements 50 on a substrate 10; a process of forming terminals 11 to 14 on the substrate 10; and a process of forming a plurality of wirings that are connected to the plurality of MR elements 50 and the terminals 11 to 14.

[0104] In the process of forming multiple MR elements 50, firstly, multiple initial MR elements that will later become multiple MR elements 50 are formed. Each of the multiple initial MR elements includes an initial magnetization fixation layer that will later become a magnetization fixation layer 51, a free layer 53, and a gap layer 52.

[0105] Next, using a laser and an external magnetic field in a predetermined direction, the magnetization direction of the initial magnetization fixing layer is fixed to the predetermined direction. For example, among the multiple initial MR elements that will later become the multiple MR elements 50 constituting the first, fourth, sixth, and seventh resistive elements R11, R14, R22, and R23, a laser is applied to the multiple initial MR elements while an external magnetic field in the first magnetization direction (-X direction) is applied. When the laser irradiation is completed, the magnetization direction of the initial magnetization fixing layer is fixed to the first magnetization direction. Thus, the initial magnetization fixing layer becomes the magnetization fixing layer 51, and the multiple initial MR elements become the multiple MR elements 50 constituting the first, fourth, sixth, and seventh resistive elements R11, R14, R22, and R23.

[0106] Furthermore, in the other initial MR elements 50 that will subsequently constitute the second, third, fifth, and eighth resistive elements R12, R13, R21, and R24, by making the direction of the external magnetic field the second magnetization direction (X direction), the magnetization direction of the initial magnetization fixing layer of each of the other initial MR elements can be fixed to the second magnetization direction. In this way, a plurality of MR elements 50 are formed.

[0107] Next, the function and effects of the magnetic encoder 1 and magnetic sensor 2 in this embodiment will be explained. In this embodiment, the first to fourth resistors R11 to R14, as described above, satisfy the necessary conditions regarding the circuit structure configuration, the necessary conditions regarding the physical configuration, and the necessary conditions regarding the magnetization of the magnetization fixing layer. Therefore, according to this embodiment, errors caused by stray magnetic fields in the direction parallel to the X direction can be reduced.

[0108] Here, we envision the case where the magnetic sensor 2 is only subjected to a stray magnetic field. For example, if the direction of the stray magnetic field is in the X direction, the free layers of the first to fourth resistors R11 to R14 are tilted from the Y direction toward the X direction due to the stray magnetic field. In this case, the resistance values ​​of the first and fourth resistors R11 and R14 increase, while the resistance values ​​of the second and third resistors R12 and R13 decrease. Therefore, the resistance values ​​of the first path 5, where the first and second resistors R11 and R12 are provided, and the resistance values ​​of the second path 6, where the third and fourth resistors R13 and R14 are provided, do not change or change almost no.

[0109] When the direction of the stray magnetic field is -X, the resistance values ​​of the first to fourth resistors R11 to R14 change in the opposite direction to the case where the direction of the stray magnetic field is X.

[0110] Based on the above, according to this embodiment, the error of the first detection signal S1 caused by stray magnetic field can be reduced.

[0111] Similarly, in this embodiment, the fifth to eighth resistors R21 to R24, as described above, satisfy the necessary conditions regarding the circuit structure configuration, the necessary conditions regarding the physical configuration, and the necessary conditions regarding the magnetization of the magnetization fixing layer. Therefore, according to this embodiment, the error in the second detection signal S2 caused by stray magnetic fields can be reduced.

[0112] Based on the above, according to this embodiment, the error of the detection value Vs caused by stray magnetic field can be reduced.

[0113] Next, referring to the results of the first and second simulations, the effects of this embodiment will be explained in further detail. First, the models of the embodiments and the comparative examples used in the first and second simulations will be described. The model of the embodiment is the model of the magnetic sensor 2 of this embodiment. The model of the comparative example is the model of the magnetic sensor 102 of the comparative example.

[0114] Figure 9 This is a plan view showing the magnetic sensor 102 of the comparative example. Figure 10 This is a circuit diagram showing the structure of the comparative example magnetic sensor 102. The magnetic sensor 102 includes a first resistive element R1, a second resistive element R2, a third resistive element R3, and a fourth resistive element R4, each configured such that its resistance value varies according to the strength of the magnetic field component MFx. Furthermore, the magnetic sensor 102 includes multiple MR elements 50. Each of the first to fourth resistive elements R1 to R4 is constructed using multiple MR elements 50.

[0115] The magnetic sensor 102 also includes a power supply port V101, a ground port G101, a first output port E101, and a second output port E102. The ground port G101 is grounded. The first and second output ports E101 and E102 are connected to the detection value generation circuit 4.

[0116] The magnetic sensor 102 generates a signal corresponding to the potential of the first output port E101 as a first detection signal S101, and generates a signal corresponding to the potential of the second output port E102 as a second detection signal S102. The detection value generation circuit 4 connected to the magnetic sensor 102 generates a detection value Vs based on the first and second detection signals S101 and S102.

[0117] The first resistor R1 is located on the path connecting the power supply port V101 and the first output port E101. The second resistor R2 is located on the path connecting the ground port G101 and the first output port E101. The third resistor R3 is located on the path connecting the ground port G101 and the second output port E102. The fourth resistor R4 is located on the path connecting the power supply port V101 and the second output port E102.

[0118] The center of gravity of the second resistor R2, viewed from the Z direction, is located at a position λ / 2 away from the center of gravity of the first resistor R1, viewed from the Z direction. The center of gravity of the third resistor R3, viewed from the Z direction, is located at a position λ / 2 away from the center of gravity of the fourth resistor R4, viewed from the Z direction. The center of gravity of the fourth resistor R4, viewed from the Z direction, is located at a position λ / 4 away from the center of gravity of the first resistor R1, viewed from the Z direction.

[0119] exist Figure 9 and Figure 10 In the diagram, the arrows depicted within the first to fourth resistors R1 to R4 indicate the direction of the first magnetization of the magnetization fixation layer of each of the plurality of MR elements 50 contained in the resistor. In the comparative example, the direction of the first magnetization is the -X direction in all of the first to fourth resistors R1 to R4.

[0120] The first to fourth resistors R1 to R4 each include multiple element groups. The structure and arrangement of the multiple element groups in each of the first to fourth resistors R1 to R4 are the same as the structure and arrangement of the multiple element groups in the first resistor R11 of the magnetic sensor 2 in this embodiment.

[0121] Next, the conditions for the first simulation will be explained. In the first simulation, the pitch λ and the pole spacing Lp are both set to 800 μm. Furthermore, the spacing between the magnetic sensor 2 and the magnetic field generator 3 in the direction parallel to the Z direction, and the spacing between the magnetic sensor 102 and the magnetic field generator 3 in the direction parallel to the Z direction, are both set to 0.15 mm. Additionally, the voltage applied to power port V1 and the voltage applied to power port V101 are both set to 1 V.

[0122] In the first simulation, while applying a stray magnetic field (parallel to the X-direction) of constant direction and intensity to magnetic sensor 2 or 102, the relative position of magnetic field generator 3 with respect to magnetic sensor 2 or 102 is varied in a direction parallel to the X-direction. Then, the maximum peak-to-peak value Vpp of the first detection signal S1 or S101 and the maximum error (hereinafter referred to as error) of the detection value Vs are determined when the relative position is varied. In the first simulation, the relative position is varied by 3200 μm.

[0123] In the following, the intensity of the stray magnetic field is represented by a positive value when the direction of the stray magnetic field is X-axis, and by a negative value when the direction of the stray magnetic field is -X-axis. Furthermore, the intensity of the stray magnetic field is represented by the magnitude of the magnetic flux density corresponding to the intensity of the stray magnetic field. In the first simulation, the stray magnetic field was varied within the range of -14 to 14 mT.

[0124] Next, the results of the first simulation will be explained. Figure 11 This is a characteristic plot showing the Vpp and error of the comparative example model obtained through the first simulation. Figure 12 This is a characteristic plot showing the Vpp and error of the model of the embodiment obtained through the first simulation. Figure 11 and Figure 12 In the diagram, the horizontal axis represents the stray magnetic field, the left vertical axis represents Vpp, and the right vertical axis represents the error. Additionally, in... Figure 11 In the figure, the curve labeled 91 represents Vpp, and the curve labeled 92 represents the error. Additionally, in... Figure 12 In the figure, the curve labeled with reference numeral 93 represents Vpp, and the curve labeled with reference numeral 94 represents the error.

[0125] According to Figure 11 and Figure 12 As can be understood from the results of the first simulation, according to this embodiment, the error can be reduced compared to the magnetic sensor 102 of the comparative example. In the first simulation, the error of the model in particular of the embodiment is approximately zero.

[0126] Next, the conditions for the second simulation will be explained. The conditions for the second simulation are the same as those for the first simulation, except for the stray magnetic field. In the second simulation, a stray magnetic field (a magnetic field parallel to the X-direction) with varying intensity depending on the relative position is applied to the magnetic sensor 2 or 102, instead of a stray magnetic field with constant direction and intensity. Furthermore, in the second simulation, the intensity of the stray magnetic field varies with the relative position within the range of -5 to 5 mT / mm. Additionally, the intensity of the stray magnetic field at a relative position of 0 μm is 0 mT. Therefore, for example, when the intensity of the stray magnetic field varies with the relative position by -3 mT / mm, the intensity of the stray magnetic field at a relative position of 3200 μm is -9.6 mT.

[0127] Next, the results of the second simulation will be explained. Figure 13 This is a characteristic plot showing the Vpp and error of the comparative example model obtained through the second simulation. Figure 14 This is a characteristic plot showing the Vpp and error of the model of the embodiment obtained through the second simulation. Figure 13 and Figure 14 In the diagram, the horizontal axis represents the stray magnetic field, the left vertical axis represents Vpp, and the right vertical axis represents the error. Additionally, in... Figure 13 In the figure, the curve labeled 95 represents Vpp, and the curve labeled 96 represents the error. Additionally, in... Figure 14 In the figure, the curve labeled with reference numeral 97 represents Vpp, and the curve labeled with reference numeral 98 represents the error.

[0128] According to Figure 13 and Figure 14 As can be understood from the results of the second simulation shown, according to this embodiment, compared with the magnetic sensor 102 of the comparative example, it is particularly able to reduce the error when the intensity of the stray magnetic field changes in a negative proportion with respect to relative position.

[0129] [Second Implementation]

[0130] Next, refer to Figure 15 and Figure 16 The lens position detection device (hereinafter referred to as the position detection device) according to the second embodiment of the present invention will be described. Figure 15 This is a perspective view showing the lens module including the position detection device of this embodiment. Figure 16 This is a perspective view showing the position detection device of this embodiment.

[0131] Figure 15 The lens module 300 shown constitutes part of, for example, a camera used in a smartphone, and is used in combination with an image sensor 310 constructed using a CMOS sensor or the like. Figure 15In the example shown, the lens module 300 includes a triangular prism-shaped prism 302 and three lenses 303A, 303B, and 303C disposed between the image sensor 310 and the prism 302. At least one of the lenses 303A, 303B, and 303C is configured to be movable by a drive device (not shown) to enable at least one of focusing and zooming.

[0132] Figure 16 This indicates any one of lenses 303A, 303B, and 303C. The lens module 300 also includes a lens holder 304 and an axis 305 to hold the lens 303. In the lens module 300, the position of the lens 303 can be changed along the optical axis direction using the lens holder 304, the axis 305, and a drive device (not shown). Figure 16 In the diagram, the arrow marked with the symbol D indicates the direction of movement of lens 303.

[0133] The lens module 300 also includes a position detection device 301 for detecting the position of the variable-position lens 303. The position detection device 301 is used to detect the position of the lens 303 during focusing or zooming.

[0134] Position detection device 301 is a magnetic position detection device, including the magnetic sensor 2 and magnetic field generator 3 described in the first embodiment. In lens module 300, magnetic sensor 2 and magnetic field generator 3 are configured such that when the position of lens 303 changes in the direction of movement D, the magnetic field component MFx (refer to...) Figure 2 The intensity of the magnetic field changes. Specifically, the magnetic sensor 2 is fixed, and the magnetic field generator 3 is configured to move together with the lens 303 in the direction of movement D. The direction of movement D is... Figure 1 and Figure 2 The X-direction shown is parallel. Therefore, when the position of lens 303 changes, the relative position of magnetic field generator 3 with respect to magnetic sensor 2 changes, resulting in a change in the intensity of the magnetic field component MFx.

[0135] The position detection device 301 also includes the detection value generation circuit 4 described in the first embodiment (see reference). Figure 4 In the position detection device 301, based on the first and second detection signals S1 and S2 generated by the magnetic sensor 2, a detection value Vs corresponding to the position of the lens 303 is generated. Furthermore, the position of the lens 303 corresponds to the relative position of the magnetic field generator 3 with respect to the magnetic sensor 2. The method for generating the detection value Vs in the position detection device 301 is the same as the method for generating the detection value Vs in the first embodiment.

[0136] The other structures, functions, and effects of this embodiment are the same as those of the first embodiment.

[0137] [Third Implementation Method]

[0138] Next, refer to Figure 17 The ranging device according to the third embodiment of the present invention will be described. Figure 17 This is a perspective view showing the ranging device of this embodiment.

[0139] Figure 17 The distance measuring device 401 shown is a device that measures the distance to an object by detecting the illuminated light, for example, as part of a vehicle-mounted LIDAR (Light Detection and Ranging) system. Figure 17 In the example shown, the ranging device 401 includes a photoelectric unit 411, an optical element 412, and a driving device (not shown).

[0140] The photoelectric unit 411 includes an optical element for illuminating light 411a and a detection element for detecting reflected light 411b from an object. The optical element 412 may be, for example, a mirror supported by a support 413. The optical element 412 is tilted relative to its exit surface in a manner that changes the respective travel directions of the light 411a and the reflected light 411b. Furthermore, the optical element 412 is configured to rotate about a predetermined rotation axis via a drive device (not shown).

[0141] The ranging device 401 also includes a position detection device for detecting the rotational position of the optical element 412. The position detection device is a magnetic position detection device, including the magnetic sensor 2 described in the first embodiment and the magnetic field generator of this embodiment. In this embodiment, the magnetic field generator is configured to rotate around a predetermined rotation axis in conjunction with the optical element 412. The magnetic field generator can rotate around the same rotation axis as the optical element 412, or it can rotate around a different rotation axis. In this embodiment, for convenience, the optical element 412 and the magnetic field generator rotate around the same rotation axis C.

[0142] The magnetic field generator is a rotating magnetic scale (N-pole and S-pole alternating around a rotation axis C). Here, the first and second examples of the magnetic field generator will be explained. First, refer to... Figure 18 and Figure 19 Let's explain the first example. Figure 18 This is a three-dimensional diagram representing the first example of a magnetic field generator. Figure 19 This is a plan view showing the first example of a magnetic field generator.

[0143] The first example of a magnetic field generator 403 has an end face 403a located at an end in a direction parallel to the rotation axis C. Multiple sets of N and S poles are disposed on the end face 403a. Figure 18 and Figure 19 In the diagram, the N pole is shaded for ease of understanding. Magnetic sensor 2 is positioned opposite end face 403a. The magnetic field component MFx at the reference position—for example, the position where magnetic sensor 2 is located (see reference...) Figure 2 The intensity of the magnetic field changes as the magnetic field generator 403 rotates.

[0144] In the first example, the two directions orthogonal to the rotation axis C can be designated as the X and Y directions, and the direction parallel to the rotation axis C and leading from the magnetic sensor 2 to the magnetic field generator 403 can be designated as the Z direction. The Y direction can be the direction from the rotation axis C to the magnetic sensor 2.

[0145] Next, refer to Figure 20 Let's explain the second example. Figure 20 This is a perspective view showing a second example of a magnetic field generator. The magnetic field generator 404 of this second example has outer peripheral surfaces 404a and 404b, respectively facing away from the rotation axis C. The outer peripheral surfaces 404a and 404b are arranged at different positions in a direction parallel to the rotation axis C. Outer peripheral surface 404a is arranged further away from the rotation axis C than outer peripheral surface 404b.

[0146] Multiple sets of N-pole and S-pole are disposed on the outer peripheral surface 404a. Figure 20 In the diagram, the N pole is shaded for ease of understanding. Magnetic sensor 2 is positioned opposite the outer peripheral surface 404a. The magnetic field component MFx at the reference position—for example, the position where magnetic sensor 2 is located (see reference...) Figure 2 The intensity of the magnetic field changes as the magnetic field generator 404 rotates.

[0147] In the second example, the direction parallel to the rotation axis C can be set as the Y direction, and the direction orthogonal to the rotation axis C and from the magnetic sensor 2 to the rotation axis C can be set as the Z direction.

[0148] The ranging device 401 also includes the detection value generation circuit 4 described in the first embodiment (see reference). Figure 4 In the ranging device 401, based on the first and second detection signals S1 and S2 generated by the magnetic sensor 2, a detection value Vs corresponding to the rotational position of the optical element 412 is generated. Furthermore, the rotational position of the optical element 412 corresponds to the rotational position of the magnetic field generator 403 or 404.

[0149] The other structures, functions, and effects of this embodiment are the same as those of the first embodiment.

[0150] [Fourth Implementation Method]

[0151] Next, refer to Figure 21 and Figure 22 The fourth embodiment of the present invention will be described. Figure 21 This is a plan view showing the magnetic sensor of this embodiment. Figure 22 This is a circuit diagram showing the structure of the magnetic sensor in this embodiment.

[0152] The magnetic sensor 202 of this embodiment has all the constituent elements of the magnetic sensor 2 of the first embodiment except for the substrate 10 and terminals 11-14. That is, the magnetic sensor 202 includes first to eighth resistors R11-R14, R21-R24, a power supply port V1, a ground port G1, a first output port E1, and a second output port E2. The structure of the first to eighth resistors R11-R14, R21-R24 and the circuit configuration of the first to eighth resistors R11-R14, R21-R24 are the same as those in the first embodiment.

[0153] The magnetic sensor 202 also includes a ninth resistor R15, a tenth resistor R16, an eleventh resistor R17, a twelfth resistor R18, a thirteenth resistor R25, a fourteenth resistor R26, a fifteenth resistor R27, and a sixteenth resistor R28. Each of the ninth to sixteenth resistors R15 to R18 and R25 to R28 is constructed using multiple MR elements 50.

[0154] The magnetic sensor 202 also includes a power supply port V2, a ground port G2, a third output port E3, and a fourth output port E4. Ground ports G1 and G2 are grounded. The magnetic sensor 202 can be driven by either a constant voltage or a constant current. When the magnetic sensor 202 is driven by a constant voltage, a specified voltage is applied to each of the power supply ports V1 and V2. When the magnetic sensor 202 is driven by a constant current, a specified current is supplied to each of the power supply ports V1 and V2.

[0155] The magnetic sensor 202 also includes two differential detectors 21 and 22. Differential detector 21 outputs the signal corresponding to the potential difference between the first and third output ports E1 and E3 as the first detection signal S11. Differential detector 22 outputs the signal corresponding to the potential difference between the second and fourth output ports E2 and E4 as the second detection signal S12.

[0156] Differential detectors 21 and 22 are connected to the detection value generation circuit 4. In this embodiment, the detection value generation circuit 4 generates a detection value Vs based on the first and second detection signals S11 and S12. Furthermore, at least one of the magnetic sensor 202 and the detection value generation circuit 4 can be configured to correct the amplitude, phase, and offset of the first and second detection signals S11 and S12 respectively. The method for generating the detection value Vs is the same as in the first embodiment, except that the first and second detection signals S11 and S12 are used instead of the first and second detection signals S1 and S2.

[0157] The ninth resistor R15 and the tenth resistor R16 are sequentially arranged from the power port V2 side on the path connecting the power port V2 and the third output port E3. The eleventh resistor R17 and the twelfth resistor R18 are sequentially arranged from the ground port G2 side on the path connecting the ground port G2 and the third output port E3. The thirteenth resistor R25 and the fourteenth resistor R26 are sequentially arranged from the ground port G2 side on the path connecting the ground port G2 and the fourth output port E4. The fifteenth resistor R27 and the sixteenth resistor R28 are sequentially arranged from the power port V2 side on the path connecting the power port V2 and the fourth output port E4.

[0158] The first magnetization of the magnetization fixing layer in the ninth, twelfth, fourteenth, and fifteenth resistors R15, R18, R26, and R27 includes a component in the second magnetization direction (X direction). The first magnetization of the magnetization fixing layer in the tenth, eleventh, thirteenth, and sixteenth resistors R16, R17, R25, and R28 includes a component in the first magnetization direction (-X direction).

[0159] The ninth to sixteenth resistors R15-R18 and R25-R28 each include multiple element groups. The structure and arrangement of the multiple element groups in each of the ninth to sixteenth resistors R15-R18 and R25-R28 are the same as the structure and arrangement of the multiple element groups in the first resistor R11 of the magnetic sensor 2 in the first embodiment.

[0160] like Figure 21 As shown, the magnetic sensor 202 also includes a substrate 210, power terminals 211 and 215, ground terminals 212 and 216, a first output terminal 213, a second output terminal 214, a third output terminal 217, and a fourth output terminal 218 disposed on the substrate 210. Power terminal 211 constitutes power port V1. Power terminal 215 constitutes power port V2. Ground terminal 212 constitutes ground port G1. Ground terminal 216 constitutes ground port G2. The first to fourth output terminals 213, 214, 217, and 218 respectively constitute the first to fourth output ports E1, E2, E3, and E4.

[0161] Here, as Figure 21 As shown, the magnetic sensor 202 is divided into a first part 202A and a second part 202B. In Figure 21In the diagram, the boundary between the first part 202A and the second part 202B is indicated by a dashed line. The second part 202B is positioned in front of the first part 202A in the Y direction. The first part 202A includes first to eighth resistors R11-R14, R21-R24, a power supply terminal 211, a ground terminal 212, and first and second output terminals 213 and 214. The second part 202B includes ninth to sixteenth resistors R15-R18, R25-R28, a power supply terminal 215, a ground terminal 216, and third and fourth output terminals 217 and 218.

[0162] The physical configurations of the first to eighth resistors R11-R14 and R21-R24 in Part 1 202A are the same as those in the first embodiment. Furthermore, the physical configurations of the ninth to sixteenth resistors R15-R18 and R25-R28 in Part 2 202B are the same as those in the first embodiment.

[0163] The ninth and eleventh resistors R15 and R17 are positioned in the X direction at the same location as the first and third resistors R11 and R13. The tenth and twelfth resistors R16 and R18 are positioned in the X direction at the same location as the second and fourth resistors R12 and R14. The thirteenth and fifteenth resistors R25 and R27 are positioned in the X direction at the same location as the fifth and seventh resistors R21 and R23. The fourteenth and sixteenth resistors R26 and R28 are positioned in the X direction at the same location as the sixth and eighth resistors R22 and R24.

[0164] Based on the structure of the first to eighth resistors R11~R14, R21~R24 and the ninth to sixteenth resistors R15~R18, R25~R28 described above, the phase difference between the ideal component of the second detection signal S12 and the ideal component of the first detection signal S11 is an odd multiple of 1 / 4 of the specified signal period (the signal period of the ideal component).

[0165] The other structures, functions, and effects of this embodiment are the same as those of the first embodiment.

[0166] Furthermore, the present invention is not limited to the embodiments described above, and various modifications are possible. For example, the number and arrangement of the MR elements 50 are arbitrary, provided that the necessary conditions of the claimed technical solution are met.

[0167] In addition, the first to eighth positions C11~C14 and C21~C24 can also be positions other than the center of gravity, such as the ends of the corresponding resistors in the -X direction.

[0168] In addition, in the first to third embodiments, the third, fourth, seventh and eighth resistors R13, R14, R23 and R24 may also be configured at positions that are integer multiples of the pitch λ in the X direction or -X direction relative to the first, second, fifth and sixth resistors R11, R12, R21 and R22, respectively.

[0169] In addition, in the fourth embodiment, the ninth to sixteenth resistors R15 to R18 and R25 to R28 may also be arranged at positions that are integer multiples of the pitch λ in the X direction or -X direction relative to the first to eighth resistors R11 to R14 and R21 to R24.

[0170] Alternatively, in the fourth embodiment, the first part 202A and the second part 202B can also be separated. Furthermore, in the fourth embodiment, resistors R11 to R18 may form a first Wheatstone bridge circuit, and resistors R21 to R28 may form a second Wheatstone bridge circuit.

[0171] Based on the above description, it can be seen that various methods and modifications of the present invention can be implemented. Therefore, within the equivalent scope of the claimed technical solutions, the present invention can be implemented in ways other than the above-described preferred methods.

Claims

1. A magnetic sensor, characterized in that, It is a magnetic sensor configured to detect the magnetic field of an object containing a magnetic field component in a first direction. The magnetic sensor includes: A first resistive element, a second resistive element, a third resistive element, and a fourth resistive element are respectively constructed in such a way that their resistance values ​​change with the intensity of the magnetic field components; Power port; Grounding port; and First output port The first resistor and the second resistor are sequentially arranged from the power port side along the first path connecting the power port and the first output port. The third resistor and the fourth resistor are sequentially arranged starting from the ground port side on the second path connecting the ground port and the first output port. The interval between the first position within the first resistor and the second position within the second resistor in the first direction is an odd multiple of half the predetermined pitch. The interval between the third position within the third resistor body and the fourth position within the fourth resistor body in the first direction is equal to an odd multiple of half the predetermined pitch. The interval between the first position and the third position in the first direction is equal to zero or an integer multiple of the specified pitch. The specified pitch is the length corresponding to one period of the change in the intensity of the magnetic field component, assuming that the intensity of the magnetic field component changes periodically along the first direction at a specified period. The magnetic sensor also includes multiple magnetoresistive elements. Each of the plurality of magnetoresistive effect elements includes a magnetized fixed layer, a free layer, and a gap layer disposed between the magnetized fixed layer and the free layer. The magnetization fixing layer has a first magnetization with a fixed direction. The free layer has a second magnetization, the direction of which can vary in a plane parallel to both the first direction and the second direction orthogonal to the first direction. The magnetized fixing layer, the free layer, and the gap layer are stacked in a third direction orthogonal to the first and second directions. The first to the fourth resistors are constructed using multiple magnetoresistive elements. The first magnetization of the magnetization fixing layer in the first resistive element and the fourth resistive element includes a component of a first magnetization direction, wherein the first magnetization direction is a direction parallel to the first direction. The first magnetization of the magnetization fixing layer in the second and third resistive elements includes a component of a second magnetization direction opposite to the first magnetization direction.

2. The magnetic sensor as described in claim 1, characterized in that, The first position is the center of gravity of the first resistive element when viewed from a direction parallel to the third party. The second position is the center of gravity of the second resistive element when viewed from a direction parallel to the third party. The third position is the center of gravity of the third resistive element when viewed from a direction parallel to the third party. The fourth position is the center of gravity of the fourth resistor when viewed from a direction parallel to the third party.

3. The magnetic sensor as described in claim 1, characterized in that, The first resistive element and the third resistive element are adjacent in the second direction. The second resistor and the fourth resistor are adjacent to each other in the second direction.

4. The magnetic sensor as described in claim 1, characterized in that, Also includes: The fifth, sixth, seventh, and eighth resistive elements are respectively constructed in such a way that their resistance values ​​change with the intensity of the magnetic field components. and Second output port The fifth resistor and the sixth resistor are sequentially arranged from the ground port side on the third path connecting the ground port and the second output port. The seventh resistor and the eighth resistor are sequentially arranged from the power port side on the fourth path connecting the power port and the second output port. The interval between the fifth position in the fifth resistor body and the sixth position in the sixth resistor body in the first direction is equal to an odd multiple of half of the predetermined pitch. The interval between the seventh position in the seventh resistor body and the eighth position in the eighth resistor body in the first direction is equal to an odd multiple of half of the predetermined pitch. The interval between the fifth position and the seventh position in the first direction is equal to zero or an integer multiple of the specified pitch. When n is an integer greater than or equal to 1, the interval between the first position and the fifth position in the first direction is equal to (4n-3) / 4 of the specified pitch. The fifth to eighth resistors are constructed using the plurality of magnetoresistive effect elements. The first magnetization of the magnetization fixing layer in the fifth and eighth resistive elements includes a component of the second magnetization direction. The first magnetization of the magnetization fixing layer in the sixth and seventh resistors includes a component of the first magnetization direction.

5. The magnetic sensor as described in claim 4, characterized in that, The fifth position is the center of gravity of the fifth resistive element when viewed from a direction parallel to the third party. The sixth position is the center of gravity of the sixth resistor when viewed from a direction parallel to the third party. The seventh position is the center of gravity of the seventh resistive element when viewed from a direction parallel to the third party. The eighth position is the center of gravity of the eighth resistor when viewed from a direction parallel to the third party.

6. The magnetic sensor as described in claim 4, characterized in that, The fifth resistor and the seventh resistor are adjacent in the second direction. The sixth resistor and the eighth resistor are adjacent to each other in the second direction.

7. The magnetic sensor as described in claim 4, characterized in that, The first resistor is adjacent to the seventh resistor but not adjacent to the eighth resistor. The eighth resistor is adjacent to the second resistor but not adjacent to the first resistor.

8. The magnetic sensor as described in claim 7, characterized in that, The third resistor is positioned at a point spaced apart from the seventh resistor by the first resistor. The fourth resistor is positioned at a point spaced apart from the eighth resistor by the second resistor. The fifth resistor is positioned at a location that is spaced from the first resistor by the seventh resistor. The sixth resistor is positioned at a location that is spaced from the second resistor by the eighth resistor.

9. The magnetic sensor as described in claim 1, characterized in that, Each of the plurality of magnetoresistive effect elements is configured such that the free layer is subjected to a bias magnetic field in a direction intersecting the first direction and the third direction.

10. The magnetic sensor as claimed in claim 1, characterized in that, The gap layer is a tunneling barrier layer.

11. A magnetic encoder, characterized in that, include: The magnetic sensor according to claim 1; and A magnetic field generator that generates the magnetic field of the object. 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 is activated, the intensity of the magnetic field component at the reference position changes.

12. A lens position detection device, characterized in that, It is a lens position detection device used to detect the position of a lens whose position can be changed. The lens position detection device includes: The magnetic sensor according to claim 1; and A magnetic field generator that generates the magnetic field of the object. The lens is configured to be movable in the first direction. The magnetic sensor and the magnetic field generator are configured such that the intensity of the magnetic field component changes when the position of the lens changes.

13. The lens position detection device as described in claim 12, characterized in that, The magnetic field generator is a magnetic ruler, wherein multiple sets of N poles and S poles are alternately arranged in the first direction.

14. A ranging device, characterized in that, It is a distance measuring device that measures the distance to an object by detecting the light it is irradiated. The ranging device includes: An optical element configured to change the direction of light travel and to rotate it; The magnetic sensor according to claim 1; and A magnetic field generator that generates the magnetic field of the object. The magnetic field generator is configured to rotate about a rotation axis in conjunction with the optical element. The intensity of the magnetic field component at the reference position changes as the magnetic field generator rotates.

15. The ranging device as described in claim 14, characterized in that, The magnetic field generator is a magnetic ruler in which multiple sets of N poles and S poles are arranged alternately around the rotation axis.

16. The ranging device as described in claim 15, characterized in that, The magnetic field generator has an end face located at one end in a direction parallel to the rotation axis. The multiple sets of N and S electrodes are disposed on the end face. The magnetic sensor is configured to face the end face.

17. The ranging device as described in claim 15, characterized in that, The magnetic field generator has an outer peripheral surface facing away from the rotation axis. The multiple sets of N and S electrodes are disposed on the outer peripheral surface. The magnetic sensor is configured to face the outer peripheral surface.

18. A manufacturing method, characterized in that, The method for manufacturing the magnetic sensor according to claim 1 is as follows. The manufacturing method includes the step of forming multiple magnetoresistive effect elements. The process of forming multiple magnetoresistive effect elements includes: The process of forming multiple initial magnetoresistive effect elements, wherein each initial magnetoresistive effect element comprises an initial magnetization fixing layer that will subsequently become the magnetization fixing layer, the free layer, and the gap layer; and The process of using a laser and an external magnetic field to fix the direction of the first magnetization of the initial magnetization fixing layer.

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