Magnetic sensor

Abstract

To provide a magnetic sensor capable of improving detection accuracy. [Solution] The magnetic sensor 1 comprises a substrate 2 and a plurality of magnetoresistive elements 4. The element width W of each of the plurality of magnetoresistive elements 4 in a first direction D1 is greater than the value obtained by multiplying the length of adjacent N poles 81 and S poles 82 of the magnetic scale 8 in the first direction D1 by 1 / 8. The first region 441 of the first magnetoresistive element 41 faces the second region 432 of the third magnetoresistive element 43 across a virtual axis C1. The first region 421 of the second magnetoresistive element 42 faces the second region 442 of the fourth magnetoresistive element 44 across a virtual axis C1. When viewed along the normal direction of the main surface 3, the centroids G1 of the element regions of the first magnetoresistive element 41 and the second magnetoresistive element 42, and the centroids G2 of the element regions of the third magnetoresistive element 43 and the fourth magnetoresistive element 44 are arranged on the main surface 3 of the substrate 2 such that they lie on the virtual axis C1.

Description

Technical Field

[0006] ,

[0001] The present disclosure relates to a magnetic sensor. More specifically, the present disclosure relates to a magnetic sensor that can move relative to a magnetic scale in which N poles and S poles are alternately magnetized.

Background Art

[0002] The magnetic position detection device disclosed in Patent Document 1 includes a magnetic scale and first to fourth magnetoresistive elements (magnetic sensors) that can move relative to the magnetic scale. When the length between the center of the N pole and the center of the S pole in the magnetized direction of the magnetic scale is λ / 2, the first to fourth magnetoresistive elements are arranged at intervals of λ / 8 in order with respect to the magnetized direction of the magnetic scale.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, the demand for higher accuracy of magnetic sensors has been increasing. In the above conventional magnetic sensor, when the width of each magnetoresistive element is made larger than before, since a plurality of magnetoresistive elements are arranged in a row along the magnetized direction of the magnetic scale, adjacent magnetoresistive elements interfere with each other. As a result, there has been a problem that the detection accuracy of the magnetic sensor decreases.

[0005] An object of the present disclosure is to provide a magnetic sensor capable of improving detection accuracy.

Means for Solving the Problems

[0006] A magnetic sensor according to one aspect of the present disclosure is a sensor that is relatively movable in a first direction, facing a magnetic scale in which north poles and south poles are alternately magnetized along the first direction. The magnetic sensor comprises a substrate, a power terminal, a ground terminal, a first output terminal, a second output terminal, and a plurality of magnetoresistive elements. The power terminal is connected to a power supply. The ground terminal is connected to ground. The first output terminal outputs a first detection signal. The second output terminal outputs a second detection signal that is 90 degrees out of phase with respect to the first detection signal. The plurality of magnetoresistive elements include a first magnetoresistive element, a second magnetoresistive element including a third magnetoresistive element and a fourth magnetoresistive element. The plurality of magnetoresistive elements are arranged on the main surface of the substrate along the first direction. The first magnetoresistive element has its first end connected to the power terminal and its second end connected to the first output terminal. The second magnetoresistive element has its first end connected to the first output terminal and its second end connected to the ground terminal. The third magnetoresistive element has its first end connected to the power terminal and its second end connected to the second output terminal. The fourth magnetoresistive element has its first end connected to the second output terminal and its second end connected to the ground terminal. Each of the plurality of magnetoresistive elements comprises a first region and a second region. The first region is located on the first side of a virtual axis set along the first direction on the main surface of the substrate. The second region is located on the second side of the virtual axis. The first region and the second region are offset in the first direction. The element width of each of the plurality of magnetoresistive elements in the first direction is greater than the length of the adjacent N pole and S pole of the magnetic scale in the first direction multiplied by 1 / 8. The first region of the first magnetoresistive element faces the second region of the third magnetoresistive element across the virtual axis. The first region of the second magnetoresistive element faces the second region of the fourth magnetoresistive element across the virtual axis. When viewed along the normal direction of the main surface, the center of gravity of the element region formed by the first magnetoresistive element and the second magnetoresistive element is located on the virtual axis, and the elements are positioned on the main surface of the substrate.When viewed along the direction normal to the main surface, the center of gravity of the element region formed by the third magnetoresistive element and the fourth magnetoresistive element is located on the virtual axis, and the elements are positioned on the main surface of the substrate.

[0007] A magnetic sensor in another aspect of the present disclosure is a sensor that is relatively movable in a first direction, facing a magnetic scale in which north poles and south poles are alternately magnetized along the first direction. The magnetic sensor comprises a substrate, a power terminal, a ground terminal, a first output terminal, a second output terminal, and a plurality of magnetoresistive elements. The power terminal is connected to a power supply. The ground terminal is connected to ground. The first output terminal outputs a first detection signal. The second output terminal outputs a second detection signal that is 90 degrees out of phase with respect to the first detection signal. The plurality of magnetoresistive elements include a first magnetoresistive element, a second magnetoresistive element, a third magnetoresistive element, a fourth magnetoresistive element, a fifth magnetoresistive element, a sixth magnetoresistive element, a seventh magnetoresistive element, and an eighth magnetoresistive element. The plurality of magnetoresistive elements are arranged on the main surface of the substrate along the first direction. The first magnetoresistive element has its first end connected to the power terminal and its second end connected to the first end of the second magnetoresistive element. The second magnetoresistive element has its second end connected to the first output terminal. The third magnetoresistive element has its first end connected to the first output terminal and its second end connected to the first end of the fourth magnetoresistive element. The fourth magnetoresistive element has its second end connected to the ground terminal. The fifth magnetoresistive element has its first end connected to the power terminal and its second end connected to the first end of the sixth magnetoresistive element. The sixth magnetoresistive element has its second end connected to the second output terminal. The seventh magnetoresistive element has its first end connected to the second output terminal and its second end connected to the first end of the eighth magnetoresistive element. The eighth magnetoresistive element has its second end connected to the ground terminal. The third magnetoresistive element or the fourth magnetoresistive element is positioned between the first magnetoresistive element and the second magnetoresistive element. The seventh magnetoresistive element or the eighth magnetoresistive element is positioned between the fifth magnetoresistive element and the sixth magnetoresistive element. Each of the plurality of magnetoresistive elements comprises a first region and a second region. The first region is located on the first side of a virtual axis set along the first direction on the main surface of the substrate. The second region is located on the second side of the virtual axis. The first region and the second region are offset in the first direction.The element width of each of the plurality of magnetoresistive elements in the first direction is greater than the length of the adjacent N pole and S pole of the magnetic scale in the first direction multiplied by 1 / 8. The first region and the second region face each other across the virtual axis. The first region is the first region of at least one magnetoresistive element among the first magnetoresistive element, the second magnetoresistive element, the third magnetoresistive element and the fourth magnetoresistive element. The second region is the second region of at least one magnetoresistive element among the fifth magnetoresistive element, the sixth magnetoresistive element, the seventh magnetoresistive element and the eighth magnetoresistive element. When viewed along the direction normal to the main surface, the centroid of the element region formed by the first magnetoresistive element, the second magnetoresistive element, the third magnetoresistive element and the fourth magnetoresistive element is located on the virtual axis, and the elements are positioned on the main surface of the substrate. When viewed along the direction normal to the main surface, the center of gravity of the element region formed by the fifth magnetoresistive element, the sixth magnetoresistive element, the seventh magnetoresistive element, and the eighth magnetoresistive element is positioned on the main surface of the substrate such that it lies on the virtual axis. [Effects of the Invention]

[0008] According to this disclosure, the detection accuracy of magnetic sensors can be improved. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic diagram of a position detection system equipped with a magnetic sensor according to Embodiment 1. [Figure 2] Figure 2 is the equivalent circuit diagram of the magnetic sensor described above. [Figure 3] Figure 3 is a conceptual diagram of the magnetic sensor mentioned above. [Figure 4] Figure 4 is an explanatory diagram illustrating the arrangement of the multiple magnetoresistive elements shown above. [Figure 5] Figure 5 is a graph showing the simulation results of the phase shift of the magnetic sensor mentioned above. [Figure 6] Figure 6 is an equivalent circuit diagram of the magnetic sensor of Embodiment 2. [Figure 7]Figure 7 is a conceptual diagram of the magnetic sensor mentioned above. [Figure 8] Figure 8 is an explanatory diagram illustrating the arrangement of the multiple magnetoresistive elements shown above. [Figure 9] Figure 9 is a plan view showing the shapes of multiple magnetoresistive elements as described above. [Figure 10] Figure 10 is a magnified view of a portion of Figure 9. [Figure 11] Figure 11 is an explanatory diagram illustrating the arrangement of multiple magnetoresistive elements in the magnetic sensor of Modified Example 1. [Figure 12] Figure 12 is an explanatory diagram illustrating the arrangement of multiple magnetoresistive elements in the magnetic sensor of Modified Example 2. [Modes for carrying out the invention]

[0010] The magnetic sensor according to the embodiment will be described in detail below with reference to the drawings. However, the figures described in the following embodiments are schematic diagrams, and the dimensional ratios of the size of each component do not necessarily reflect the actual dimensional ratios. Furthermore, the configuration described in the following embodiments is merely one example of the disclosure. The disclosure is not limited to the following embodiments, and various modifications are possible depending on the design, etc., as long as the effects of the disclosure can be achieved.

[0011] (Embodiment 1) (1) Overview Figure 1 is a schematic diagram of a position detection system 9 equipped with a magnetic sensor 1 according to Embodiment 1. As shown in Figure 1, the position detection device 9 comprises a magnetic scale 8 and a magnetic sensor 1.

[0012] The magnetic scale 8 has N poles 81 and S poles 82 magnetized alternately along the first direction D1. The first direction D1 is the magnetization direction of the magnetic scale 8. In the present embodiment, the first direction D1 is a linear direction. The magnetic scale 8 is a linear scale magnetized linearly. In the present embodiment, in the first direction D1, the width of each of the N poles 81 and S poles 82 is λ / 2. λ corresponds to the length in the first direction D1 of adjacent N poles 81 and S poles 82 of the magnetic scale 8. In the present embodiment, λ may be referred to as the magnetization pitch of the magnetic scale 8. Also, λ corresponds to the length of one period of the change in the intensity of the magnetic field component when it is assumed that the intensity of the magnetic field component of the magnetic scale 8 changes periodically at a predetermined period along the direction parallel to the first direction D1.

[0013] (Magnetic sensor) The magnetic sensor 1 is disposed to face the magnetic scale 8. The magnetic sensor 1 is movable relative to the magnetic scale 8 in the first direction D1 (see FIG. 1). "The magnetic sensor 1 is disposed to face the magnetic scale 8" means that the surface (main surface 3) of the substrate 2 of the magnetic sensor 1 is disposed to face the magnetic scale 8 with a predetermined gap therebetween. Also, "the magnetic sensor 1 moves relative to the magnetic scale 8" includes that the magnetic sensor 1 moves with respect to the fixed magnetic scale 8, that the magnetic scale 8 moves with respect to the fixed magnetic sensor 1, and that both the magnetic sensor 1 and the magnetic scale 8 move. The position detection system 9 detects the relative position of how much the magnetic sensor 1 has moved with respect to the magnetic scale 8.

[0014] In the present embodiment, in a state where the surface (main surface 3) of the substrate 2 of the magnetic sensor 1 is arranged to face the magnetic scale 8, the direction perpendicular (orthogonal) to the main surface 3 of the substrate 2 is described as the "vertical direction" (Z-axis direction in FIG. 1 etc.). Also, the side of the magnetic scale 8 (positive direction in the Z-axis direction) with respect to the main surface 3 of the substrate 2 of the magnetic sensor 1 is described as "upward". Further, a direction orthogonal to the vertical direction and parallel to the surface (main surface 3) of the substrate 2 of the magnetic sensor 1 (X-axis direction in FIG. 1 etc.) is described as the "left-right direction", and when viewing the magnetic sensor 1 from the front, the right side (positive direction in the X-axis direction) is described as "right", and the left side is described as "left". Furthermore, a direction orthogonal to both the vertical direction and the left-right direction, that is, a direction parallel to the surface (main surface 3) of the substrate 2, may be described as the "front-back direction" (Y-axis direction in FIG. 1 etc.). Also, in the following description, the left-right direction may be referred to as the first direction D1. Note that the arrows indicating the respective directions in the drawings are merely for explanation and do not accompany an entity.

[0015] FIG. 2 is an equivalent circuit diagram of the magnetic sensor 1. As shown in FIG. 2, the magnetic sensor 1 includes a plurality of magnetoresistive elements 4, a power supply terminal 51, a ground terminal 52, a first output terminal 53, and a second output terminal 54.

[0016] The plurality of magnetoresistive elements 4 includes a first magnetoresistive element 41, a second magnetoresistive element 42, a third magnetoresistive element 43, and a fourth magnetoresistive element 44. Hereinafter, the first magnetoresistive element 41, the second magnetoresistive element 42, the third magnetoresistive element 43, and the fourth magnetoresistive element 44 may be collectively referred to as the plurality of magnetoresistive elements 4. Also, any one of the first magnetoresistive element 41, the second magnetoresistive element 42, the third magnetoresistive element 43, and the fourth magnetoresistive element 44 may be simply referred to as the "magnetoresistive element 4".

[0017] The power terminal 51 is connected to a power supply. For example, a predetermined voltage is applied to the power terminal 51. The ground terminal 52 is connected to ground. In this embodiment, the multiple magnetoresistive elements 4 are electrically connected to form a full-bridge circuit. Note that the resistance of the wiring between each of the multiple magnetoresistive elements 4 and the terminals is small compared to the magnetoresistive elements and can be ignored, so the resistance of the wiring is not considered when forming the full-bridge circuit.

[0018] The first magnetoresistive element 41 has its first end connected to the power terminal 51 and its second end connected to the first output terminal 53. The second magnetoresistive element 42 has its first end connected to the first output terminal 53 and its second end connected to the ground terminal 52. The third magnetoresistive element 43 has its first end connected to the power terminal 51 and its second end connected to the second output terminal 54. The fourth magnetoresistive element 44 has its first end connected to the second output terminal 54 and its second end connected to the ground terminal 52.

[0019] In this embodiment, the first magnetoresistive element 41 and the second magnetoresistive element 42 constitute the first half-bridge circuit BR1. The third magnetoresistive element 43 and the fourth magnetoresistive element 44 constitute the second half-bridge circuit BR2. As the magnetic sensor 1 moves relative to the magnetic scale 8, a first detection signal is output from the first output terminal 53 of the first half-bridge circuit BR1. A second detection signal, which is 90 degrees out of phase with respect to the first detection signal, is output from the second output terminal 54 of the second half-bridge circuit BR2. Therefore, the first detection signal is sometimes called a sine signal, and the second detection signal is sometimes called a cosine signal.

[0020] The first output terminal 53 of the first half-bridge circuit BR1 and the second output terminal 54 of the second half-bridge circuit BR2 are connected to a signal processing circuit (not shown). The first detection signal and the second detection signal are processed in the signal processing circuit, and based on the two output signals, the relative position of the magnetic sensor 1 with respect to the magnetic scale 8 in the first direction D1 can be detected.

[0021] Figure 3 is a conceptual diagram of the magnetic sensor 1. As shown in Figure 3, the magnetic sensor 1 comprises a substrate 2 and a plurality of magnetoresistive elements 4. Note that in Figure 3, the wiring connecting the plurality of magnetoresistive elements 4 to each terminal (see Figure 2) is omitted.

[0022] The substrate 2 has two main surfaces facing each other in the thickness direction. Hereinafter, the surface facing the magnetic scale 8 will be referred to as the main surface 3. The substrate 2 is an insulating substrate. In this embodiment, the substrate 2 is formed in a rectangular shape when viewed from above.

[0023] Multiple magnetoresistive elements 4 are arranged on the main surface 3 of the substrate 2 along a first direction D1. The multiple magnetoresistive elements 4 are fixed on the main surface 3 of the substrate 2 so that the relative positions between each element do not change. In other words, the multiple magnetoresistive elements 4 fixed on the main surface 3 of the substrate 2 move integrally with the substrate 2 along the first direction D1. In this embodiment, each element of the multiple magnetoresistive elements 4 is an element that utilizes the magnetoresistance effect (MRS), a phenomenon in which the resistance value changes due to an external magnetic field. Each of the multiple magnetoresistive elements 4 has anisotropy in the direction of magnetic field detection, i.e., the direction of magnetization, and the magnetization direction (first direction D1) of the magnetic scale 8 is the direction of magnetization.

[0024] Each of the multiple magnetoresistive elements 4 is formed as a thin film on the main surface 3 of the substrate 2. Each of the multiple magnetoresistive elements 4 has a zigzag pattern of equally spaced wiring of a constant width to ensure a predetermined resistance value (see, for example, Figures 9 and 10). In this embodiment, the shape, center position, and size of the element region formed by the magnetoresistive elements 4 can be approximated by the outer shape of the magnetoresistive element 4. The outer shape of the magnetoresistive element 4 is, for example, the shape of the smallest rectangular region surrounding the magnetoresistive element.

[0025] In this embodiment, as shown in Figure 3, each of the multiple magnetoresistive elements 4 has two rectangular element regions formed in a stepped manner when viewed along the direction normal to the main surface 3 of the substrate 2. All element regions of the multiple magnetoresistive elements 4 are the same shape and size. The direction of the short side (first direction D1) of each of the multiple magnetoresistive elements 4 is the direction of magnetic field detection. In Figure 3, the length in the longitudinal direction of each of the multiple magnetoresistive elements 4 is shown as L, and the width in the short side direction is shown as W.

[0026] Figure 4 is an explanatory diagram illustrating the arrangement of multiple magnetoresistive elements 4 of the magnetic sensor 1. As shown in Figure 4, multiple magnetoresistive elements 4 are arranged on the main surface 3 of the substrate 2. Note that in Figure 4, the wiring connecting the multiple magnetoresistive elements 4 arranged on the main surface 3 of the substrate 2 to each terminal (see Figure 2) is omitted from the illustration. Also, in Figure 4, dot hatching is applied to the first magnetoresistive element 41 and the second magnetoresistive element 42 to distinguish them from the first magnetoresistive element 41 and the second magnetoresistive element 42 which constitute the first half-bridge circuit BR1 and the third magnetoresistive element 43 and the fourth magnetoresistive element 44 which constitute the second half-bridge circuit BR2. As shown in Figure 4, when arranging multiple magnetoresistive elements 4 on the main surface 3 of the substrate 2, a reference virtual axis C1 is set in a direction along the first direction D1 on the main surface 3 of the substrate 2. In this embodiment, the virtual axis C1 is a straight line set along the first direction D1 on the main surface 3 of the substrate 2. Note that the direction along the first direction D1 refers to the direction parallel to the first direction D1 (the X-axis direction in the diagram). The direction parallel to the first direction D1 is not limited to being perfectly parallel to the first direction D1, but may be shifted by a few degrees (for example, 2 degrees or less) from being parallel to the first direction D1.

[0027] In general, a straight line is defined as a type of curve that is a geometric object without thickness, extending infinitely straight without endpoints. The virtual axis C1 may be set or identified as a line segment on the main surface 3 of the substrate 2 that has a finite thickness (width) in the front-to-back direction (Y-axis direction in the figure) and a finite length (i.e., two ends) in the left-to-right direction (X-axis direction in the figure).

[0028] Multiple magnetoresistive elements 4 are located on a virtual axis C1 set along a first direction D1 on the main surface 3 of the substrate 2. Along the first direction D1, the first magnetoresistive element 41, the third magnetoresistive element 43, the second magnetoresistive element 42, and the fourth magnetoresistive element 44 are arranged on the main surface 3 of the substrate 2 in order from the left end (X-axis in the figure). In other words, in this embodiment, the first magnetoresistive element 41 and the third magnetoresistive element 43 are arranged adjacent to each other in the first direction D1. The third magnetoresistive element 43 and the second magnetoresistive element 42 are arranged adjacent to each other in the first direction D1. The second magnetoresistive element 42 and the fourth magnetoresistive element 44 are arranged adjacent to each other in the first direction D1.

[0029] Furthermore, each of the multiple magnetoresistive elements 4 comprises a first region and a second region (see Figures 3 and 4). The first region is located on the first side (positive side of the Y-axis in Figures 3 and 4) of a virtual axis C1 set along a first direction D1 on the main surface 3 of the substrate 2. The second region is located on the second side (negative side of the Y-axis in Figures 3 and 4). The first and second regions are offset in the first direction D1.

[0030] The first region 411 of the first magnetoresistive element 41 faces the second region 432 of the third magnetoresistive element 43 across the virtual axis C1. The first region 421 of the second magnetoresistive element 42 faces the second region 442 of the fourth magnetoresistive element 44 across the virtual axis C1.

[0031] The element width W of each of the multiple magnetoresistive elements 4 in the direction along the first direction D1 is greater than λ / 8 (see Figure 3). In other words, the element width W of each of the multiple magnetoresistive elements 4 in the first direction D1 is greater than the length (magnetization pitch) of adjacent N poles 81 and S poles 82 of the magnetic scale 8 in the first direction D1 multiplied by 1 / 8. Furthermore, an upper limit is set for the element width W of each of the multiple magnetoresistive elements 4 in the first direction D1 so that adjacent elements in the first direction D1 do not interfere with each other. That is, the width W of each of the multiple magnetoresistive elements 4 is set to satisfy equation (1).

[0032] λ / 8 <W<λ / 4···(1) Furthermore, as shown in Figure 4, when viewed along the normal direction (Z direction in the figure) of the main surface 3 of the substrate 2, the centroid G1 of the element region formed by the first magnetoresistive element 41 and the second magnetoresistive element 42 is positioned on the virtual axis C1 on the main surface 3 of the substrate 2.

[0033] Furthermore, when viewed along the normal direction (Z direction in the figure) of the main surface 3 of the substrate 2, the centroid G2 of the element region formed by the third magnetoresistive element 43 and the fourth magnetoresistive element 44 is positioned on the virtual axis C1 on the main surface 3 of the substrate 2.

[0034] In this disclosure, the "centroid of the element region of a magnetoresistive element" refers to the geometric centroid of the element region formed by the magnetoresistive element on a two-dimensional plane (more specifically, the main surface 3 of the substrate 2). In other words, the centroid G1 of the element region formed by the first magnetoresistive element 41 and the second magnetoresistive element 42, and the centroid G2 of the element region formed by the third magnetoresistive element 43 and the fourth magnetoresistive element 44 are calculated to lie on a virtual axis C1, assuming that the mass distribution of the materials constituting each of the multiple magnetoresistive elements 4 (for example, the laminated films constituting ferromagnetic materials, non-magnetic metals, etc.) is uniform.

[0035] Furthermore, the geometric centroid is a point, and a point is generally defined as a concept used to define a precise location in space, and is defined as having no volume, area, or length whatsoever. Each of the centroids G1 and G2 may have an extent (area) in the front-to-back direction (Y-axis direction in Figures 3 and 4) and the left-to-right direction (X-axis direction in Figures 3 and 4) on a two-dimensional plane (main surface 3 of the substrate 2). Each of the centroids G1 and G2 may be defined or identified by a shape (e.g., a circle or an ellipse) having a certain area (diameter) on the main surface 3 of the substrate 2.

[0036] Incidentally, in recent years, there has been a growing demand for higher precision in magnetic sensors 1. To reduce the error of magnetic sensors 1, if the width of each magnetoresistive element is made larger than λ / 8 relative to a magnetic scale 8 with a magnetization pitch of λ / 2, then if multiple magnetoresistive elements are arranged in a line along the magnetization direction of the magnetic scale, adjacent magnetoresistive elements will interfere with each other. As a result, there was a problem in that the detection accuracy of the magnetic sensor decreased.

[0037] Therefore, in this embodiment, as described above, the width W of each of the multiple magnetoresistive elements 4 in the first direction D1 of the main surface 3 of the substrate 2 is made larger than in the conventional design (see equation (1) above). Furthermore, as shown in Figure 4, the first region 411 of the first magnetoresistive element 41 faces the second region 432 of the third magnetoresistive element 43 across the virtual axis C1, and the first region 421 of the second magnetoresistive element 42 faces the second region 442 of the fourth magnetoresistive element 44 across the virtual axis C1. As a result, adjacent magnetoresistive elements do not interfere with each other in the first direction D1. Also, when viewed along the normal direction of the main surface 3 of the substrate 2 (Z direction in the figure), the centroids G1 of the element regions of the first magnetoresistive element 41 and the second magnetoresistive element 42, and the centroids G2 of the element regions of the third magnetoresistive element 43 and the fourth magnetoresistive element 44 are located on the virtual axis C1. This makes it possible to suppress the phase difference between the first detection signal and the second detection signal caused by misalignment during the mounting of the magnetic sensor 1, thereby improving the detection accuracy of the magnetic sensor 1.

[0038] Phase shift will be explained in more detail in "(2.3) Phase Shift".

[0039] (2) Details The magnetic sensor 1 according to Embodiment 1 will be described in detail below with reference to the drawings.

[0040] (2.1) Configuration As shown in Figure 4, in the first direction D1, the third magnetoresistive element 43 is positioned between the first magnetoresistive element 41 and the second magnetoresistive element 42. In the first direction D1, the second magnetoresistive element 42 is positioned between the third magnetoresistive element 43 and the fourth magnetoresistive element 44. In other words, along the first direction D1, the first magnetoresistive element 41, the third magnetoresistive element 43, the second magnetoresistive element 42, and the fourth magnetoresistive element 44 are positioned on the main surface 3 of the substrate 2 in order from the left end (the negative side of the X-axis in Figure 4).

[0041] The first magnetoresistive element 41 is located at the left edge of the main surface 3 of the substrate 2. The first magnetoresistive element 41 is adjacent to the third magnetoresistive element 43, which is located on the right side (the positive side of the X-axis in Figure 4), in the first direction D1. The first magnetoresistive element 41 comprises a first region 411 and a second region 412. The first region 411 is located on the first side of the virtual axis C1 (the positive side of the Y-axis in Figure 4). The second region 412 is located on the second side of the virtual axis C1 (the negative side of the Y-axis in Figure 4). In this embodiment, the first region 411 is rectangular when viewed along the normal direction of the main surface 3 of the substrate 2 (the Z-axis direction in Figure 4). The second region 412 is rectangular when viewed along the normal direction of the main surface 3 of the substrate 2. The first region 411 and the second region 412 are the same shape and size. The first region 411 is shifted to the right (the positive side of the X-axis in Figure 4) in the first direction D1 relative to the second region 412. As a result, the first region 411 of the first magnetoresistive element 41 faces the second region 432 of the third magnetoresistive element 43 across the virtual axis C1. The first magnetoresistive element 41 does not interfere with the adjacent third magnetoresistive element 43 in the first direction D1.

[0042] Furthermore, in this embodiment, as shown in Figure 3, the second region 412 of the adjacent first magnetoresistive element 41 and the second region 432 of the third magnetoresistive element 43 are positioned at a distance of λ / 8 in the first direction D1. The statement that "the second region 412 of the first magnetoresistive element 41 and the second region 432 of the third magnetoresistive element 43 are shifted by λ / 8 in the first direction D1" means that the distance between the centers in the short-side direction of the rectangular second region 412 of the first magnetoresistive element 41 and the second region 432 of the third magnetoresistive element 43 corresponds to a length of λ / 8. Similarly, the first region 411 of the adjacent first magnetoresistive element 41 and the first region 431 of the third magnetoresistive element 43 are positioned at a distance of λ / 8 in the first direction D1.

[0043] The third magnetoresistive element 43 is adjacent to the first magnetoresistive element 41, which is located on the left side (negative side of the X-axis in the figure), in the first direction D1. The third magnetoresistive element 43 comprises a first region 431 and a second region 432. The first region 431 is located on the first side of the virtual axis C1 (positive side of the Y-axis in the figure). The second region 432 is located on the second side of the virtual axis C1 (negative side of the Y-axis in the figure). In this embodiment, the first region 431 is rectangular when viewed along the normal direction of the main surface 3 of the substrate 2 (Z-axis direction in the figure). The second region 432 is rectangular when viewed along the normal direction of the main surface 3 of the substrate 2. The second region 432 is shifted to the left (negative side of the X-axis in the figure) in the first direction D1 relative to the first region 431. As a result, the second region 432 of the third magnetoresistive element 43 faces the first region 411 of the first magnetoresistive element 41 across the virtual axis C1. The third magnetoresistive element 43 does not interfere with the adjacent first magnetoresistive element 41 in the first direction D1.

[0044] The second magnetoresistive element 42 is adjacent to the fourth magnetoresistive element 44, which is located to the right (positive side of the X-axis in the figure), in the first direction D1. The second magnetoresistive element 42 comprises a first region 421 and a second region 422. The first region 421 is located on the first side of the virtual axis C1 (positive side of the Y-axis in the figure). The second region 422 is located on the second side of the virtual axis C1 (negative side of the Y-axis in the figure). The first region 421 is offset to the right (positive side of the X-axis in the figure) in the first direction D1 relative to the second region 422. As a result, the first region 421 of the second magnetoresistive element 42 faces the second region 442 of the fourth magnetoresistive element 44 across the virtual axis C1. The second magnetoresistive element 42 does not interfere with the adjacent fourth magnetoresistive element 44 in the first direction D1.

[0045] Furthermore, in this embodiment, as shown in Figure 3, the first region 421 of the adjacent second magnetoresistive element 42 and the first region 441 of the fourth magnetoresistive element 44 are positioned at a distance of λ / 8 in the first direction D1. "The first region 421 of the second magnetoresistive element 42 and the first region 441 of the fourth magnetoresistive element 44 are shifted by λ / 8 in the first direction D1" means that the distance between the centers in the short-side direction of the rectangular first region 421 of the second magnetoresistive element 42 and the first region 441 of the fourth magnetoresistive element 44 corresponds to a length of λ / 8. Similarly, the second region 422 of the adjacent second magnetoresistive element 42 and the second region 442 of the fourth magnetoresistive element 44 are positioned at a distance of λ / 8 in the first direction D1.

[0046] The fourth magnetoresistive element 44 is adjacent to the second magnetoresistive element 42, which is located on the left side (negative side of the X-axis in the figure), in the first direction D1. The fourth magnetoresistive element 44 comprises a first region 441 and a second region 442. The first region 441 is located on the first side of the virtual axis C1 (positive side of the Y-axis in the figure). The second region 442 is located on the second side of the virtual axis C1 (negative side of the Y-axis in the figure). The second region 442 is shifted to the left of the first region 441 in the first direction D1 (negative side of the X-axis in the figure). As a result, the second region 442 of the fourth magnetoresistive element 44 faces the first region 421 of the second magnetoresistive element 42 across the virtual axis C1. The fourth magnetoresistive element 44 does not interfere with the adjacent second magnetoresistive element 42 in the first direction D1.

[0047] (2.2) Operation Instructions Next, the operating principle of the magnetic sensor 1 of this embodiment will be explained using Figure 3.

[0048] In the following section, we will focus on the first magnetoresistive element 41 in the magnetic sensor 1 and describe the operation of the magnetic sensor 1 when it moves relative to the magnetic scale 8 along the first direction D1.

[0049] First, assume that the magnetic sensor 1 moves from its position in Figure 3 to the left (negative side of the X-axis in the figure) relative to the magnetic scale 8, and that the first magnetoresistive element 41 is positioned at the boundary between the north pole 81 and the south pole 82 of the magnetic scale 8. In this case, the magnetic field line component passing through the first magnetoresistive element 41 increases, and the resistance value of the first magnetoresistive element 41 decreases.

[0050] Next, assume that the magnetic sensor 1 moves further to the left (towards the negative side of the X-axis in the figure) relative to the magnetic scale 8, and that the first magnetoresistive element 41 is positioned in the center of the N pole 81. In this case, the magnetic field line component passing through the first magnetoresistive element 41 decreases, and the resistance value of the first magnetoresistive element 41 increases.

[0051] Next, let's assume that the magnetic sensor 1 moves further to the left (negative side of the X-axis in the figure) relative to the magnetic scale 8, and the first magnetoresistive element 41 is positioned at the next boundary between the north pole 81 and the south pole 82. In this case, although the direction of the magnetic field is reversed compared to when it was positioned at the previous boundary between the north pole 81 and the south pole 82, the resistance value of the first magnetoresistive element 41 is the same for both the forward and reverse directions of the magnetic field. In other words, the resistance value when the first magnetoresistive element 41 is positioned at the boundary between the north pole 81 and the south pole 82 is the same as when it was positioned at the previous boundary between the north pole 81 and the south pole 82.

[0052] As described above, when the magnetic sensor 1 moves from the position shown in Figure 3 to the left (negative side of the X-axis in the figure) relative to the magnetic scale 8, the resistance value of the third magnetoresistive element 43 shows a roughly sinusoidal change in resistance value, and the change in the resistance value of the third magnetoresistive element 43 completes one period with a length of λ / 2, which corresponds to one period of the intensity of the magnetic field component of the magnetic scale 8. Therefore, the first output terminal 53 of the first half-bridge circuit BR1, which includes the first magnetoresistive element 41, outputs a roughly sinusoidal output voltage with the same period as the change in resistance value of the first magnetoresistive element 41, in accordance with the change in resistance values ​​of the first magnetoresistive element 41 and the second magnetoresistive element 42.

[0053] On the other hand, the second output terminal 54 of the second half-bridge circuit BR2, which is composed of the third magnetoresistive element 43 and the fourth magnetoresistive element 44, outputs an output voltage that is approximately sinusoidal with a period similar to that of the first magnetoresistive element 41 and the second magnetoresistive element 42. In this embodiment, as shown in Figure 3, the adjacent first magnetoresistive element 41 and the third magnetoresistive element 43 are positioned λ / 8 apart in the first direction D1. Also, the adjacent second magnetoresistive element 42 and the fourth magnetoresistive element 44 are positioned λ / 8 apart in the first direction D1. A distance of λ / 4 corresponds to a phase difference of 180 degrees in terms of resistance change. Therefore, in the magnetic sensor 1, the output from the first output terminal 53 of the first half-bridge circuit BR1 and the output from the second output terminal 54 of the second half-bridge circuit BR2 have a phase difference of 90 degrees.

[0054] The first output terminal 53 of the first half-bridge circuit BR1 and the second output terminal 54 of the second half-bridge circuit BR2 are connected to a signal processing circuit (not shown). The first detection signal and the second detection signal are processed in the signal processing circuit, and based on the two output signals, the relative position of the magnetic sensor 1 with respect to the magnetic scale 8 in the first direction D1 can be detected.

[0055] (2.3) Phase shift Next, the phase shift of the magnetic sensor 1 in this embodiment will be described.

[0056] During the manufacturing of the magnetic sensor 1, when mounting the magnetic sensor 1 facing the magnetic scale 8 (see Figure 1), the position of the main surface 3 of the substrate 2 of the magnetic sensor 1 may be misaligned with respect to the magnetic scale 8. When the center of the main surface 3 of the substrate 2 is taken as the origin O of the XYZ axis coordinate system (see Figure 4), the rotational misalignment on the main surface 3 of the substrate 2 around the Z axis is more significant than the vertical misalignment (Z axis direction) between the main surface 3 of the substrate 2 and the magnetic scale 8. Hereafter, the rotational misalignment on the main surface 3 of the substrate 2 around the Z axis with respect to the magnetic scale 8 may be referred to as mounting misalignment. Due to such mounting misalignment, a phase shift between the first detection signal and the second detection signal may occur in the magnetic sensor 1. The phase shift can be considered as the difference (phase difference) between the position of the centroid G1 of the element regions of the first magnetoresistive element 41 and the second magnetoresistive element 42, which constitute the first half-bridge circuit BR1 that outputs the first detection signal, and the position of the centroid G2 of the element regions of the third magnetoresistive element 43 and the fourth magnetoresistive element 44, which constitute the second half-bridge circuit BR2 that outputs the second detection signal.

[0057] Figure 5 is a graph showing the simulation results of the phase shift of the magnetic sensor 1 in this embodiment. In this embodiment, when the rotation angle is zero, i.e., there is no positional shift, the centers of gravity G1 and G2 are positioned on the virtual axis C1 (see Figure 4). Therefore, as shown in Figure 4, the phase shift peaks at zero when the centers of gravity G1 and G2 are aligned parallel to the first direction D1, which is the direction of movement of the magnetic sensor 100, and the phase shift when the centers of gravity G1 and G2 are rotated 20 degrees in the negative direction is approximately -30 degrees. The phase shift when the centers of gravity G1 and G2 are rotated 20 degrees in the positive direction is approximately -30 degrees.

[0058] Thus, the magnetic sensor 1 of this embodiment minimizes the effects of rotational misalignment and suppresses phase misalignment caused by mounting misalignment, thereby improving the detection accuracy of the magnetic sensor 1.

[0059] (Embodiment 2) Next, the magnetic sensor 1A of Embodiment 2 will be described using Figures 6 to 10. Components similar to those in Embodiment 1 described above are denoted by the same reference numerals and their description is omitted.

[0060] The magnetic sensor 1A of Embodiment 2 is the same as the magnetic sensor 1 of Embodiment 1 in that it comprises a substrate 2, a power terminal 51, a ground terminal 52, a first output terminal 53, a second output terminal 54, and a plurality of magnetoresistive elements 4.

[0061] While the magnetic sensor 1 of Embodiment 1 above forms a full bridge circuit with four first magnetoresistive elements 41 to 4th magnetoresistive elements 44 (see Figure 2), the magnetic sensor 1A of Embodiment 2 differs in that it forms a full bridge circuit with eight first magnetoresistive elements 41 to 8th magnetoresistive elements 48.

[0062] Figure 6 is an equivalent circuit diagram of the magnetic sensor 1A of Embodiment 2. As shown in Figure 6, the first magnetoresistive element 41 has its first end connected to the power terminal 51 and its second end connected to the first end of the second magnetoresistive element 42. The second end of the second magnetoresistive element 42 is connected to the first output terminal 53. The third magnetoresistive element 43 has its first end connected to the first output terminal 53 and its second end connected to the first end of the fourth magnetoresistive element 44. The second end of the fourth magnetoresistive element 44 is connected to the ground terminal 52. The fifth magnetoresistive element 45 has its first end connected to the power terminal 51 and its second end connected to the first end of the sixth magnetoresistive element 46. The second end of the sixth magnetoresistive element 46 is connected to the second output terminal 54. The seventh magnetoresistive element 47 has its first end connected to the second output terminal 54 and its second end connected to the first end of the eighth magnetoresistive element 48. The second end of the eighth magnetoresistive element 48 is connected to the ground terminal 52.

[0063] In this embodiment, the first magnetoresistive elements 41 to the fourth magnetoresistive elements 44 constitute a first half-bridge circuit BR1. A first detection signal (sine signal) is output from the first output terminal 53 of the first half-bridge circuit BR1. The fifth magnetoresistive elements 45 to the eighth magnetoresistive elements 48 constitute a second half-bridge circuit BR2. A second detection signal (cosine signal) with a phase shift of 90 degrees from the first detection signal is output from the second output terminal 54 of the second half-bridge circuit BR2.

[0064] Figure 7 is a conceptual diagram of the magnetic sensor 1A of Embodiment 2. As shown in Figure 7, in the magnetic sensor 1A of Embodiment 2, similar to the magnetic sensor 1 of Embodiment 1, each of the multiple magnetoresistive elements 4 has two rectangular element regions formed in a stepped manner when viewed along the direction normal to the main surface 3 of the substrate 2. All element regions of the multiple magnetoresistive elements 4 are the same shape and size. The direction of detection of the magnetic field is the direction of the short side (first direction D1) of each of the multiple magnetoresistive elements 4. Here again, the length in the longitudinal direction of each of the multiple magnetoresistive elements 4 is indicated by L, and the width in the short side direction is indicated by W.

[0065] Figure 8 is an explanatory diagram illustrating the arrangement of multiple magnetoresistive elements 4 of the magnetic sensor 1A. As shown in Figure 8, multiple magnetoresistive elements 4 are arranged on the main surface 3 of the substrate 2. In Figure 8, dot hatching is applied to the first magnetoresistive elements 41 to 4th magnetoresistive elements 44, which constitute the first half-bridge circuit BR1, and the fifth magnetoresistive elements 45 to 8th magnetoresistive elements 48, which constitute the second half-bridge circuit BR2.

[0066] As shown in Figure 8, the first magnetoresistive elements 41 to the eighth magnetoresistive elements 48 are located on a virtual axis C1 set along the first direction D1 on the main surface 3 of the substrate 2. Along the first direction D1, the second magnetoresistive element 42, the third magnetoresistive element 43, the first magnetoresistive element 41, the fifth magnetoresistive element 45, the fourth magnetoresistive element 44, the eighth magnetoresistive element 48, the sixth magnetoresistive element 46, and the seventh magnetoresistive element 47 are arranged on the main surface 3 of the substrate 2 in order from the left end (the X-axis in the figure).

[0067] In the first direction D1, among the first to fourth magnetoresistance elements 41 to 44, the third magnetoresistance element 43 is positioned between the second magnetoresistance element 42 and the first magnetoresistance element 41. In the first direction D1, among the first to fourth magnetoresistance elements 41 to 44, the first magnetoresistance element 41 is positioned between the third magnetoresistance element 43 and the fourth magnetoresistance element 44.

[0068] In the first direction D1, among the fifth magnetoresistance elements 45 to the eighth magnetoresistance elements 48, the eighth magnetoresistance element 48 is positioned between the fifth magnetoresistance element 45 and the sixth magnetoresistance element 46. In the first direction D1, among the fifth magnetoresistance elements 45 to the eighth magnetoresistance elements 48, the sixth magnetoresistance element 46 is positioned between the eighth magnetoresistance element 48 and the seventh magnetoresistance element 47.

[0069] Furthermore, each of the multiple magnetoresistive elements 4 comprises a first region and a second region (see Figures 7 and 8). The first region is located on the first side (positive side of the Y-axis in the figure) of a virtual axis C1 set along a first direction D1 on the main surface 3 of the substrate 2. The second region is located on the second side (positive side of the Y-axis in the figure) of the virtual axis C1. The first and second regions are offset in the first direction D1.

[0070] The element width W of each of the multiple magnetoresistive elements 4 in the direction along the first direction D1 is greater than λ / 8. In other words, the element width W of each of the multiple magnetoresistive elements 4 in the first direction D1 is greater than the value obtained by multiplying the length (magnetization pitch) of adjacent N poles 81 and S poles of the magnetic scale 8 in the first direction D1 by 1 / 8. Furthermore, an upper limit is set for the element width W of each of the multiple magnetoresistive elements 4 in the first direction D1 so that adjacent elements do not interfere with each other in the first direction D1. That is, the element width W of each of the multiple magnetoresistive elements 4 is set to satisfy equation (2).

[0071] λ / 8 <W<λ / 4···(2) The first magnetoresistive element 41 faces the fifth magnetoresistive element 45 across the virtual axis C1. The fourth magnetoresistive element 44 faces the eighth magnetoresistive element 48 across the virtual axis C1.

[0072] The first region 411 of the first magnetoresistive element 41 and the second region 452 of the fifth magnetoresistive element 45 face each other across the virtual axis C1. The first region 441 of the fourth magnetoresistive element 44 and the second region 482 of the eighth magnetoresistive element 48 face each other across the virtual axis C1.

[0073] When viewed along the normal direction (Z direction in the figure) of the main surface 3 of the substrate 2, the centroid G1 of the element region formed by the first magnetoresistive element 41, the second magnetoresistive element 42, the third magnetoresistive element 43, and the fourth magnetoresistive element 44 is positioned on the main surface 3 of the substrate 2 such that it lies on the virtual axis C1.

[0074] Furthermore, when viewed along the normal direction (Z direction in the figure) of the main surface 3 of the substrate 2, the centroid G2 of the element region formed by the fifth magnetoresistive element 45, the sixth magnetoresistive element 46, the seventh magnetoresistive element 47, and the eighth magnetoresistive element 48 is positioned on the main surface 3 of the substrate 2 such that it lies on the virtual axis C1.

[0075] In this embodiment, as described above, the width W of each of the multiple magnetoresistive elements 4 in the first direction D1 of the main surface 3 of the substrate 2 is made larger than in the conventional (see equation (2) above). Furthermore, since the first region 411 of the first magnetoresistive element 41 and the second region 452 of the fifth magnetoresistive element 45 face each other across the virtual axis C1, adjacent first magnetoresistive elements 41 and 5 magnetoresistive elements 45 do not interfere with each other in the first direction D1. Also, since the first region 441 of the fourth magnetoresistive element 44 and the second region 482 of the eighth magnetoresistive element 48 face each other across the virtual axis C1, adjacent fourth magnetoresistive elements 44 and 8 magnetoresistive elements 48 do not interfere with each other in the first direction D1. Furthermore, when viewed along the normal direction (Z direction in the figure) of the main surface 3 of the substrate 2, the centroid G1 of the element regions of the first magnetoresistive element 41 to the fourth magnetoresistive element 44 and the centroid G2 of the element regions of the fifth magnetoresistive element 45 to the eighth magnetoresistive element 48 are located on the virtual axis C1. This makes it possible to suppress the phase shift of the second detection signal relative to the first detection signal caused by the positional misalignment during mounting of the magnetic sensor 1A, thereby improving the detection accuracy of the magnetic sensor 1.

[0076] Figure 9 is a plan view showing the shapes of the first magnetoresistance elements 41 to the eighth magnetoresistance elements 48 shown in Figure 8. As shown in Figure 9, the first magnetoresistance element 41, the second magnetoresistance element 42, the third magnetoresistance element 43, the fourth magnetoresistance element 44, the fifth magnetoresistance element 45, the sixth magnetoresistance element 46, the seventh magnetoresistance element 47, and the eighth magnetoresistance element 48 are arranged on the main surface 3 of the substrate 2.

[0077] Figure 10 is a magnified view of a portion of Figure 9. As shown in Figure 10, the first region 411 of the first magnetoresistive element 41 faces the second region 452 of the fifth magnetoresistive element 45 across a virtual axis C1 (not shown). The first region 441 of the fourth magnetoresistive element 44 faces the second region 482 of the eighth magnetoresistive element 48 across a virtual axis C1 (not shown). Here, wiring sections are arranged on the main surface 3 of the substrate 2 around each of the first magnetoresistive elements 41 to the eighth magnetoresistive elements 48. The wiring patterns connect each of the first magnetoresistive elements 41 to the eighth magnetoresistive elements 48 to their terminals (see Figure 6).

[0078] Thus, with the magnetic sensor 1A of this embodiment, the wiring patterns of the first magnetoresistive element 41 to the eighth magnetoresistive element 48 can be laid out on the main surface 3 of the substrate 2 without overlapping. In other words, there is no need to increase the steps such as forming the wiring pattern by laminating it into two layers or forming a protective film. As a result, pattern design is easy and the wiring can be formed in only one layer, thus simplifying the manufacturing process.

[0079] (Determination of the arrangement of magnetoresistive elements) From images of the main surface 3 of the substrate 2, as shown in Figures 9 and 10, it is possible to determine whether the multiple magnetoresistive elements 4 in the magnetic sensor 1A are arranged as shown in Figure 8. Below, an example of the procedure for determining the arrangement of magnetoresistive elements will be described.

[0080] (A1) Extraction of the outer shape of the element region For example, based on an image of the main surface 3 of the substrate 2 captured by a camera, eight rectangular patterns formed in a step-like manner (more specifically, including the first and second regions of the rectangles) are extracted, and the element regions of the first magnetoresistive element 41 to the eighth magnetoresistive element 48 on the main surface 3 of the substrate 2 are identified. At this time, it can be determined that the width W of each element region of the first magnetoresistive element 41 to the eighth magnetoresistive element 48 in the first direction D1 satisfies equation (2).

[0081] (A2) Determination of the layout of the element region Based on the information from the eight extracted rectangular patterns and the wiring patterns connected to them, it is determined how the element regions of the first magnetoresistive element 41 to the eighth magnetoresistive element 48 are arranged on the main surface 3 of the substrate 2. This allows it to be determined that the first magnetoresistive element 41 to the eighth magnetoresistive element 48 are arranged along the first direction D1 on the main surface 3 of the substrate 2, as shown in Figure 8. Furthermore, it can be determined that the second magnetoresistive element 42, the third magnetoresistive element 43, the first magnetoresistive element 41, the fifth magnetoresistive element 45, the fourth magnetoresistive element 44, the eighth magnetoresistive element 48, the sixth magnetoresistive element 46, and the seventh magnetoresistive element 47 are arranged along the first direction D1, starting from the left end (the negative side of the X-axis in the figure).

[0082] (A3) Extraction of the centroid of the element region The centroid G1 of the element region of the first magnetoresistance element 41 to the fourth magnetoresistance element 44 and the centroid G2 of the element region of the fifth magnetoresistance element 45 to the eighth magnetoresistance element 48 are extracted.

[0083] (A4) Imaginary line passing through the centroid A straight line (virtual axis C1) is drawn passing through the extracted centroids G1 and G2, and it is determined whether it aligns with the first direction. This allows us to determine, as shown in Figure 8, that the first region 411 of the first magnetoresistive element 41 faces the second region 452 of the fifth magnetoresistive element 45 across the virtual axis C1, and that the first region 441 of the fourth magnetoresistive element 44 faces the second region 482 of the eighth magnetoresistive element 48 across the virtual axis C1.

[0084] By following the procedures described in (A1) to (A4) above, it is possible to determine whether the multiple magnetoresistive elements 4 in the magnetic sensor 1A are arranged as shown in Figure 8.

[0085] The entity executing the above procedure may be a computer system having one or more processors and memory.

[0086] (3) Variant The above embodiments are merely one of many embodiments of this disclosure. These embodiments can be modified in various ways depending on the design, etc., as long as they achieve the objectives of this disclosure. The modifications described below can be combined and applied as appropriate.

[0087] (3.1) Variation 1 A modified example 1 of the magnetic sensor 1A of Embodiment 2, specifically a magnetic sensor 1B, will be described using Figure 11. As shown in Figure 11, the magnetic sensor 1B of Modified Example 1 is similar to the magnetic sensor 1A of Embodiment 2 in that it includes first magnetoresistive elements 41 to eighth magnetoresistive elements 48. In the magnetic sensor 1B of Modified Example 1, the first region 431 of the third magnetoresistive element 43 and the second region 452 of the fifth magnetoresistive element 45 face each other across a virtual axis C1. The first region 411 of the first magnetoresistive element 41 and the second region 482 of the eighth magnetoresistive element 48 face each other across a virtual axis C1. The first region 441 of the fourth magnetoresistive element 44 and the second region 462 of the sixth magnetoresistive element 46 face each other across a virtual axis C1.

[0088] In the magnetic sensor 1A of Embodiment 2 described above, two sets of magnetoresistive elements 4 face each other across the virtual axis C1, whereas in the magnetic sensor 1B of Modification 1, three sets of magnetoresistive elements 4 face each other across the virtual axis C1. Therefore, the magnetic sensor 1B of Modification 1 can be further miniaturized in the first direction D1 compared to the magnetic sensor 1A of Embodiment 2 described above.

[0089] (3.2) Variation 2 A modified version 2 of the magnetic sensor 1A of Embodiment 2, the magnetic sensor 1C, will be described with reference to Figure 12. As shown in Figure 12, the magnetic sensor 1C of Modified Version 2 is the same as the magnetic sensor 1B of Modified Version 1 in that it includes the first magnetoresistive elements 41 to the eighth magnetoresistive elements 48. In the magnetic sensor 1C of Modified Version 2, the first region 421 of the second magnetoresistive element 42 and the second region 482 of the eighth magnetoresistive element 48 face each other across the virtual axis C1. The first region 431 of the third magnetoresistive element 43 and the second region 452 of the fifth magnetoresistive element 45 face each other across the virtual axis C1. The first region 411 of the first magnetoresistive element 41 and the second region 462 of the sixth magnetoresistive element 46 face each other across the virtual axis C1. The first region 441 of the fourth magnetoresistive element 44 and the second region 472 of the seventh magnetoresistive element 47 face each other across the virtual axis C1.

[0090] In the magnetic sensor 1B of the modified example 1 described above, three sets of magnetoresistive elements face each other across the virtual axis C1, whereas in the magnetic sensor 1C of the modified example 2, four sets of magnetoresistive elements face each other across the virtual axis C1. Therefore, the magnetic sensor 1C of the modified example 2 can be further miniaturized in the first direction D1 compared to the magnetic sensor 1B of the embodiment 2 described above.

[0091] Thus, it is sufficient that the first region of at least one magnetoresistive element 4 from the first magnetoresistive element 41 to the fourth magnetoresistive element 44 and the second region of at least one magnetoresistive element 4 from the fifth magnetoresistive element 45 to the eighth magnetoresistive element 48 face each other across the virtual axis C1.

[0092] (3.3) Modification example 3 Furthermore, as another modification of the magnetic sensor 1A of Embodiment 2, the first magnetoresistive elements 41 to 4th magnetoresistive elements 44 constituting the first half-bridge circuit BR1 and the fifth magnetoresistive elements 45 to 8th magnetoresistive elements 48 constituting the second half-bridge circuit BR2 can be combined in the ways shown in Tables 1 to 4 below. Each row in Tables 1 and 3 shows the arrangement order of the first magnetoresistive elements 41 to 4th magnetoresistive elements 44 in the first direction D1. Each row in Tables 2 and 4 shows the arrangement order of the fifth magnetoresistive elements 45 to 8th magnetoresistive elements 48 in the first direction D1. In other words, R1 to R4 in Tables 1 and 3 correspond to the first magnetoresistive elements 41 to 4th magnetoresistive elements 44, and R5 to R8 in Tables 2 and 4 correspond to the fifth magnetoresistive elements 45 to 8th magnetoresistive elements 48.

[0093] For example, the arrangement of the first magnetoresistive elements 41 to the fourth magnetoresistive elements 44 (dot hatching in Figure 8) in the above embodiment corresponds to the combinations in the first row of Table 1, and the arrangement of the fifth magnetoresistive elements 45 to the eighth magnetoresistive elements 48 (see Figure 8) corresponds to the combinations in the first row of Table 2.

[0094] Furthermore, in the above embodiment, a third magnetoresistance element 43 is positioned between the second magnetoresistance element 42 and the first magnetoresistance element 41 in the first direction D1, but a fourth magnetoresistance element 44 may be positioned between the second magnetoresistance element 42 and the first magnetoresistance element 41. Also, in the first direction D1, an eighth magnetoresistance element 48 is positioned between the fifth magnetoresistance element 45 and the sixth magnetoresistance element 46, but a seventh magnetoresistance element 47 may be positioned between the fifth magnetoresistance element 45 and the sixth magnetoresistance element 46.

[0095] As described above, the four combinations in Table 1 can be applied to the four combinations in Table 2 (16 combinations). Also, the four combinations in Table 3 can be applied to the four combinations in Table 4 (16 combinations). In other words, the first magnetoresistive elements 41 to 4th magnetoresistive elements 44 that constitute the first half-bridge circuit BR1 of the magnetic sensor 1 in the above embodiment, and the fifth magnetoresistive elements 45 to 8th magnetoresistive elements 48 that constitute the second half-bridge circuit BR2, can be combined in a total of 32 ways.

[0096] [Table 1]

[0097] [Table 2]

[0098] [Table 3]

[0099] [Table 4]

[0100] In the above combination, the first magnetoresistive elements 41 to 4th magnetoresistive elements 44 constituting the first half-bridge circuit BR1 in Tables 1 and 3 are located on the left side of the main surface 3 of the substrate 2 (for example, the negative side of the X-axis in Figure 8). Also, the fifth magnetoresistive elements 45 to 8th magnetoresistive elements 48 constituting the second half-bridge circuit BR2 in Tables 2 and 4 are located on the right side (for example, the positive side of the X-axis in Figure 8). The first magnetoresistive elements 41 to 4th magnetoresistive elements 44 and the fifth magnetoresistive elements 45 to 8th magnetoresistive elements 48 may be swapped. In other words, the first magnetoresistive elements 41 to 4th magnetoresistive elements 44 constituting the first half-bridge circuit BR1 in Tables 1 and 3 may be located on the right side (for example, the positive side of the X-axis in Figure 8). Also, the fifth magnetoresistive elements 45 to 8th magnetoresistive elements 48 constituting the second half-bridge circuit BR2 in Tables 2 and 4 may be located on the left side (for example, the negative side of the X-axis in Figure 8).

[0101] (3.4) Other variations In the magnetic sensor 1 of Embodiment 1 and the magnetic sensor 1A of Embodiment 2 described above, each of the multiple magnetoresistive elements 4 has two rectangular element regions (first region and second region) formed in a stepped shape in a plan view, but they may also be formed in an elliptical shape. In short, it is sufficient that the centroids G1 and G2 of the element regions of the multiple magnetoresistive elements 4 are arranged on the main surface 3 of the substrate 2 so that they lie on the virtual axis C1.

[0102] (summary) Based on the embodiments described above, the following aspects are disclosed.

[0103] The magnetic sensor (1) of the first embodiment is a sensor that is relatively movable in a first direction (D1) opposite a magnetic scale (8) which has alternating N poles (81) and S poles (82) magnetized along a first direction (D1). The magnetic sensor (1) comprises a substrate (2), a power terminal (51), a ground terminal (52), a first output terminal (53), a second output terminal (54), and a plurality of magnetoresistive elements (4). The power terminal (51) is connected to a power supply. The ground terminal (52) is connected to ground. The first output terminal (53) outputs a first detection signal. The second output terminal (54) outputs a second detection signal which is 90 degrees out of phase with respect to the first detection signal. The plurality of magnetoresistive elements (4) include a first magnetoresistive element (41), a second magnetoresistive element (42), a third magnetoresistive element (43), and a fourth magnetoresistive element (44). Multiple magnetoresistive elements (4) are arranged on the main surface (3) of the substrate (2) along a first direction (D1). The first magnetoresistive element (41) has its first end connected to a power terminal (51) and its second end connected to a first output terminal (53). The second magnetoresistive element (42) has its first end connected to a first output terminal (53) and its second end connected to a ground terminal (52). The third magnetoresistive element (43) has its first end connected to a power terminal (51) and its second end connected to a second output terminal (54). The fourth magnetoresistive element (44) has its first end connected to a second output terminal (54) and its second end connected to a ground terminal (52). Each of the multiple magnetoresistive elements (4) comprises a first region (411, 421, 431, 441) and a second region (412, 422, 432, 442). The first region (411, 421, 431, 441) is located on the first side of a virtual axis (C1) set along a first direction (D1) on the main surface (3) of the substrate (2). The second region (412, 422, 432, 442) is located on the second side of the virtual axis (C1). The first region (411, 421, 431, 441) and the second region (412, 422, 432, 442) are offset in the first direction (D1). The element width (W) of each of the multiple magnetoresistive elements (4) in the first direction (D1) is greater than the length (λ) of adjacent N poles (81) and S poles (82) of the magnetic scale (8) in the first direction (D1) multiplied by 1 / 8.The first region (411) of the first magnetoresistive element (41) faces the second region (432) of the third magnetoresistive element (43) across the virtual axis (C1). The first region (421) of the second magnetoresistive element (42) faces the second region (442) of the fourth magnetoresistive element (44) across the virtual axis (C1). When viewed along the normal direction of the main surface (3), the centroid (G1) of the element region formed by the first magnetoresistive element (41) and the second magnetoresistive element (42) is positioned on the main surface (3) of the substrate (2) such that it lies on the virtual axis (C1). When viewed along the normal direction of the main surface (3), the centroid (G2) of the element region formed by the third magnetoresistive element (43) and the fourth magnetoresistive element (44) is positioned on the main surface (3) of the substrate (2) such that it lies on the virtual axis (C1).

[0104] In this embodiment, the width (W) of each of the first magnetoresistive elements (41) to the fourth magnetoresistive elements (44) in the first direction (D1) of the main surface (3) of the substrate (2) is made larger than in the conventional embodiment. Furthermore, the first region (411) of the first magnetoresistive element (41) faces the second region (432) of the third magnetoresistive element (43) across the virtual axis (C1). And the first region (421) of the second magnetoresistive element (42) faces the second region (442) of the fourth magnetoresistive element (44) across the virtual axis (C1). As a result, adjacent magnetoresistive elements (4) do not interfere with each other in the first direction (D1). Furthermore, the centroids (G1) of the element regions of the first magnetoresistive element (41) and the second magnetoresistive element (42), and the centroids (G2) of the element regions of the third magnetoresistive element (43) and the fourth magnetoresistive element (44) are positioned on the virtual axis (C1). This makes it possible to suppress the phase shift of the second detection signal relative to the first detection signal caused by mounting misalignment of the magnetic sensor (1), thereby improving the detection accuracy of the magnetic sensor (1).

[0105] The magnetic sensor (1A) of the second embodiment is a sensor that is relatively movable in the first direction (D1) opposite a magnetic scale (8) which has alternating N poles (81) and S poles (82) magnetized along the first direction (D1). The magnetic sensor (1) comprises a substrate (2), a power terminal (51), a ground terminal (52), a first output terminal (53), a second output terminal (54), and a plurality of magnetoresistive elements (4). The power terminal (51) is connected to a power supply. The ground terminal (52) is connected to ground. The first output terminal (53) outputs a first detection signal. The second output terminal (54) outputs a second detection signal which is 90 degrees out of phase with respect to the first detection signal. The multiple magnetoresistive elements (4) include a first magnetoresistive element (41), a second magnetoresistive element (42), a third magnetoresistive element (43), a fourth magnetoresistive element (44), a fifth magnetoresistive element (45), a sixth magnetoresistive element (46), a seventh magnetoresistive element (47), and an eighth magnetoresistive element (48). The multiple magnetoresistive elements (4) are arranged on the main surface (3) of the substrate (2) along a first direction (D1). The first end of the first magnetoresistive element (41) is connected to a power terminal (51), and its second end is connected to the first end of the second magnetoresistive element (42). The second end of the second magnetoresistive element (42) is connected to a first output terminal (53). The first end of the third magnetoresistive element (43) is connected to a first output terminal (53), and its second end is connected to the first end of the fourth magnetoresistive element (44). The fourth magnetoresistive element (44) has its second end connected to the ground terminal (52). The fifth magnetoresistive element (45) has its first end connected to the power terminal (51) and its second end connected to the first end of the sixth magnetoresistive element (46). The sixth magnetoresistive element (46) has its second end connected to the second output terminal (54). The seventh magnetoresistive element (47) has its first end connected to the second output terminal (54) and its second end connected to the first end of the eighth magnetoresistive element (48). The eighth magnetoresistive element (48) has its second end connected to the ground terminal (52). The third magnetoresistive element (43) or the fourth magnetoresistive element (44) is positioned between the first magnetoresistive element (41) and the second magnetoresistive element (42). The seventh magnetoresistive element (47) or the eighth magnetoresistive element (48) is positioned between the fifth magnetoresistive element (45) and the sixth magnetoresistive element (46).Each of the multiple magnetoresistive elements (4) comprises a first region (411, 421, 431, 441, 451, 461, 471, 481) and a second region (412, 422, 432, 442, 452, 462, 472, 482). The first region (411, 421, 431, 441, 451, 461, 471, 481) is located on the first side of a virtual axis (C1) set along a first direction (D1) on the main surface (3) of the substrate (2). The second region (412, 422, 432, 442, 452, 462, 472, 482) is located on the second side of the virtual axis (C1). The first region (411, 421, 431, 441, 451, 461, 471, 481) and the second region (412, 422, 432, 442, 452, 462, 472, 482) are offset in the first direction (D1). The element width (W) of each of the multiple magnetoresistive elements (4) in the first direction (D1) is greater than the length (λ) of adjacent N poles (81) and S poles (82) of the magnetic scale (8) in the first direction (D1) multiplied by 1 / 8. The first region (411, 421, 431, 441) and the second region (452, 462, 472, 482) face each other across a virtual axis (C1). The first region (411, 421, 431, 441) is the first region of at least one magnetoresistive element from among the first magnetoresistive element (41), the second magnetoresistive element (42), the third magnetoresistive element (43), and the fourth magnetoresistive element (44). The second region (452, 462, 472, 482) is the second region of at least one magnetoresistive element from among the fifth magnetoresistive element (45), the sixth magnetoresistive element (46), the seventh magnetoresistive element (47), and the eighth magnetoresistive element (48). The elements are arranged on the main surface (3) of the substrate (2) such that, when viewed along the direction normal to the main surface (3), the centroid (G1) of the element region formed by the first magnetoresistive element (41), the second magnetoresistive element (42), the third magnetoresistive element (43), and the fourth magnetoresistive element (44) lies on the virtual axis (C1). When viewed along the normal direction of the main surface (3), the centroid (G2) of the element region formed by the fifth magnetoresistive element (45), the sixth magnetoresistive element (46), the seventh magnetoresistive element (47), and the eighth magnetoresistive element (48) is positioned on the main surface (3) of the substrate (2) such that it lies on the virtual axis (C1).

[0106] In this embodiment, the width (W) of each of the first magnetoresistive elements (41) to the eighth magnetoresistive elements (48) in the first direction (D1) of the main surface (3) of the substrate (2) is made larger than in the conventional embodiment. Furthermore, since the first region (411, 421, 431, 441) and the second region (452, 462, 472, 482) face each other across a virtual axis (C1), adjacent magnetoresistive elements (4) in the first direction (D1) do not interfere with each other. In addition, the centroid (G1) of the element region of the first magnetoresistive elements (41) to the fourth magnetoresistive elements (44) and the centroid (G2) of the element region of the fifth magnetoresistive elements (45) to the eighth magnetoresistive elements (48) are located on the virtual axis (C1). This makes it possible to suppress the phase difference between the second detection signal and the first detection signal caused by misalignment during the mounting of the magnetic sensors (1A, 1B, 1C), thereby improving the detection accuracy of the magnetic sensors (1A, 1B, 1C).

[0107] In the third embodiment of the magnetic sensor (1A), in the second embodiment, the first magnetoresistive element (41) faces the fifth magnetoresistive element (45) across the virtual axis (C1). The fourth magnetoresistive element (44) faces the eighth magnetoresistive element (48) across the virtual axis (C1).

[0108] According to this embodiment, the wiring portions of the first magnetoresistive element (41) to the eighth magnetoresistive element (48) can be laid out on the main surface (3) of the substrate (2) so as not to overlap, making pattern design easier, and the wiring portion can be formed in only one layer, thus simplifying the manufacturing process.

[0109] The configuration relating to the third embodiment is not essential to the magnetic sensor (1A) and can be omitted as appropriate. [Explanation of symbols]

[0110] 1, 1A, 1B, 1C Magnetic Sensors 2 circuit boards 3 Main surface 4 Multiple magnetoresistive elements 8 Magnetic scale 9. Position detection system 41 First magnetoresistive element 42 Second magnetoresistance element 43 Third magnetoresistance element 44. Fourth magnetoresistive element 45 Fifth magnetoresistive element 46. ​​Sixth magnetoresistive element 47. Seventh magnetoresistance element 48. Eighth magnetoresistive element 51 Power terminal 52 Ground terminal 53. First output terminal 54 Second output terminal 411 First region (first magnetoresistive element) 412 Second region (first magnetoresistive element) 421 First region (second magnetoresistive element) 422 Second region (second magnetoresistive element) 431 First region (third magnetoresistive element) 432 Second region (third magnetoresistive element) 441 First region (fourth magnetoresistive element) 442 Second region (fourth magnetoresistive element) 451 First region (5th magnetoresistive element) 452 Second region (5th magnetoresistive element) 461 First region (sixth magnetoresistive element) 462 Second region (sixth magnetoresistive element) 471 First region (7th magnetoresistive element) 472 Second region (7th magnetoresistive element) 481 First region (8th magnetoresistive element) 482 Second region (8th magnetoresistive element) 81 N pole 82 S pole D1 1st direction C1 Virtual Axis Centroid of the G1 and G2 element regions W is the width of the magnetoresistive element. L is the element length of the magnetoresistive element. λ Magnetization pitch

Claims

1. A magnetic sensor that is movable relative to a magnetic scale in a first direction, with the scale having alternating N poles and S poles magnetized along the first direction, circuit board and Power terminals connected to the power supply, The ground terminal connected to the ground, A first output terminal from which the first detection signal is output, A second output terminal outputs a second detection signal that is 90 degrees out of phase with respect to the first detection signal, The device comprises a plurality of magnetoresistive elements, including a first magnetoresistive element, a second magnetoresistive element, a third magnetoresistive element, and a fourth magnetoresistive element. The plurality of magnetoresistive elements are arranged on the main surface of the substrate along the first direction, The first magnetoresistive element has its first end connected to the power supply terminal and its second end connected to the first output terminal. The second magnetoresistive element has its first end connected to the first output terminal and its second end connected to the ground terminal. The third magnetoresistive element has its first end connected to the power supply terminal and its second end connected to the second output terminal. The fourth magnetoresistive element has its first end connected to the second output terminal and its second end connected to the ground terminal. Each of the plurality of magnetoresistive elements is A first region is located on the main surface of the substrate on the first side of a virtual axis set along the first direction, A second region is located on the second side of the virtual axis, The first region and the second region are offset in the first direction. The element width of each of the plurality of magnetoresistive elements in the first direction is greater than the value obtained by multiplying the length of the adjacent N pole and S pole of the magnetic scale in the first direction by 1 / 8. The first region of the first magnetoresistive element is opposite the second region of the third magnetoresistive element, with the virtual axis in between. The first region of the second magnetoresistive element is opposite the second region of the fourth magnetoresistive element, with the virtual axis in between. When viewed along the normal direction of the main surface, the center of gravity of the element region formed by the first magnetoresistive element and the second magnetoresistive element is located on the virtual axis, and the main surface of the substrate is positioned accordingly. When viewed along the normal direction of the main surface, the center of gravity of the element region formed by the third magnetoresistive element and the fourth magnetoresistive element is located on the virtual axis, as the elements are arranged on the main surface of the substrate. Magnetic sensor.

2. A magnetic sensor that is movable relative to a magnetic scale in a first direction, with the scale having alternating N poles and S poles magnetized along the first direction, circuit board and Power terminals connected to the power supply, The ground terminal connected to the ground, A first output terminal from which the first detection signal is output, A second output terminal outputs a second detection signal that is 90 degrees out of phase with respect to the first detection signal, The system comprises a plurality of magnetoresistive elements, including a first magnetoresistive element, a second magnetoresistive element, a third magnetoresistive element, a fourth magnetoresistive element, a fifth magnetoresistive element, a sixth magnetoresistive element, a seventh magnetoresistive element, and an eighth magnetoresistive element. The plurality of magnetoresistive elements are arranged on the main surface of the substrate along the first direction, The first magnetoresistive element has its first end connected to the power terminal and its second end connected to the first end of the second magnetoresistive element. The second magnetoresistive element has its second end connected to the first output terminal. The third magnetoresistive element has its first end connected to the first output terminal and its second end connected to the first end of the fourth magnetoresistive element. The fourth magnetoresistive element has its second end connected to the ground terminal. The fifth magnetoresistive element has its first end connected to the power terminal and its second end connected to the first end of the sixth magnetoresistive element. The sixth magnetoresistive element has its second end connected to the second output terminal. The seventh magnetoresistive element has its first end connected to the second output terminal and its second end connected to the first end of the eighth magnetoresistive element. The eighth magnetoresistive element has its second end connected to the ground terminal. The third magnetoresistive element or the fourth magnetoresistive element is positioned between the first magnetoresistive element and the second magnetoresistive element. The seventh magnetoresistive element or the eighth magnetoresistive element is positioned between the fifth magnetoresistive element and the sixth magnetoresistive element. Each of the plurality of magnetoresistive elements is A first region is located on the main surface of the substrate on the first side of a virtual axis set along the first direction, A second region is located on the second side of the virtual axis, The first region and the second region are offset in the first direction. The element width of each of the plurality of magnetoresistive elements in the first direction is greater than the value obtained by multiplying the length of the adjacent N pole and S pole of the magnetic scale in the first direction by 1 / 8. The first region of at least one of the first, second, third, and fourth magnetoresistive elements and the second region of at least one of the fifth, sixth, seventh, and eighth magnetoresistive elements are opposite each other across the virtual axis. When viewed along the direction normal to the main surface, the center of gravity of the element region formed by the first magnetoresistive element, the second magnetoresistive element, the third magnetoresistive element, and the fourth magnetoresistive element is located on the virtual axis, and the elements are positioned on the main surface of the substrate. When viewed along the direction normal to the main surface, the element region formed by the fifth magnetoresistive element, the sixth magnetoresistive element, the seventh magnetoresistive element, and the eighth magnetoresistive element is positioned on the main surface of the substrate such that the center of gravity of the element region is on the virtual axis. Magnetic sensor.

3. The first magnetoresistive element faces the fifth magnetoresistive element across the virtual axis, The fourth magnetoresistive element is facing the eighth magnetoresistive element across the virtual axis. The magnetic sensor according to claim 2.

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