Position detection device, lens module, imaging device, and distance measuring device

Abstract

To provide a position detection device capable of exhibiting high position detection accuracy.SOLUTION: A position detection device includes a magnetic sensor, and a first magnetic field generation part. The first magnetic field generation part is arranged to be opposite to and spaced apart from the magnetic sensor in a first axis direction, has a first multipolar magnet which includes a plurality of N poles and S poles adjacent to each other in the first axis direction, and generates a first magnetic field which reaches the magnetic sensor. The magnetic sensor and the first magnetic field generation part are provided so as to be relatively movable in a second axis direction orthogonal to the first axis direction. A center position of the magnetic sensor in a third axis direction orthogonal to both the first axis direction and the second axis direction is different from the center position of the first multipolar magnet in the third axis direction.SELECTED DRAWING: Figure 4A

Description

[Technical field]

[0001] The present invention relates to a position detection device, a lens module, an imaging device, and a distance measuring device that are equipped with a magnetic sensor. [Background technology]

[0002] Position detection devices using magnetic sensors have been proposed so far. The applicant has proposed, for example, a camera module equipped with a position detection device (see, for example, Patent Document 1). In this camera module, the position detection device detects the position of a lens that moves when adjusting the focus. Patent Document 2 also proposes a lens driving device having a position detection magnet and a magnetic detection member that detect the moving position of a lens holding member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-082445 A [Patent Document 2] International Publication No. 2018 / 051729 Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for higher position detection accuracy for position detection devices using magnetic sensors.

[0005] It is desirable to provide a position detection device, a lens module, an imaging device, and a distance measuring device that are capable of achieving high position detection accuracy. [Means for solving the problem]

[0006] A position detection device according to an embodiment of the present technology includes a magnetic sensor and a first magnetic field generating unit. The first magnetic field generating unit is disposed so as to face the magnetic sensor at a distance in a first axial direction, has a first multi-pole magnet including a plurality of N poles and a plurality of S poles adjacent to each other in the first axial direction, and generates a first magnetic field that reaches the magnetic sensor. The magnetic sensor and the first magnetic field generating unit are provided so as to be relatively movable in a second axial direction perpendicular to the first axial direction. A center position of the magnetic sensor in a third axial direction perpendicular to both the first axial direction and the second axial direction is different from a center position of the first multi-pole magnet in the third axial direction.

[0007] A lens module according to an embodiment of the present technology includes a magnetic sensor, a first magnetic field generating unit, a second magnetic field generating unit, and a lens. The first magnetic field generating unit is disposed to face the magnetic sensor at a distance in a first axial direction, has a first multi-pole magnet including a plurality of N poles and S poles adjacent to each other along the first axial direction, and generates a first magnetic field that reaches the magnetic sensor. The second magnetic field generating unit generates a second magnetic field. The magnetic sensor and the second magnetic field generating unit, the first magnetic field generating unit, and the lens are provided so as to be relatively movable along a second axial direction perpendicular to the first axial direction. The center position of the magnetic sensor in a third axial direction perpendicular to both the first axial direction and the second axial direction is different from the center position of the first multi-pole magnet in the third axial direction.

[0008] An imaging device according to an embodiment of the present technology includes an imaging element and a lens module. The lens module includes a magnetic sensor, a first magnetic field generating unit, a second magnetic field generating unit, and a lens. The first magnetic field generating unit is disposed to face the magnetic sensor at a distance in a first axial direction, has a first multi-pole magnet including a plurality of N poles and S poles adjacent to each other along the first axial direction, and generates a first magnetic field that reaches the magnetic sensor. The second magnetic field generating unit generates a second magnetic field. The magnetic sensor and the second magnetic field generating unit, the first magnetic field generating unit, and the lens are provided so as to be relatively movable along a second axial direction perpendicular to the first axial direction. The center position of the magnetic sensor in a third axial direction perpendicular to both the first axial direction and the second axial direction is different from the center position of the first multi-pole magnet in the third axial direction.

[0009] A distance measuring device according to an embodiment of the present technology measures a distance to an object by detecting irradiated light. The distance measuring device includes an optical element, a magnetic sensor, and a magnetic field generating unit. The optical element is configured to rotate while changing the traveling direction of light. The magnetic field generating unit is disposed to face the magnetic sensor at a distance in a first axis direction, has a multi-pole magnet including a plurality of N poles and S poles adjacent to each other along the first axis direction, and generates a magnetic field that reaches the magnetic sensor. The magnetic sensor and the magnetic field generating unit are provided so as to be relatively movable in a second axis direction perpendicular to the first axis direction. The magnetic field generating unit is configured to rotate in the second axis direction around the rotation axis in conjunction with the optical element. A center position of the magnetic sensor in a third axis direction perpendicular to both the first axis direction and the second axis direction is different from a center position of the first multi-pole magnet in the third axis direction. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic perspective view illustrating an example of the overall configuration of an imaging device equipped with a lens module including a position detection device according to an embodiment of the present technology. [Diagram 2] FIG. 2 is a side view that typically illustrates the inside of the imaging device shown in FIG. [Diagram 3] FIG. 3 is a front view that typically illustrates the inside of the imaging device shown in FIG. [Figure 4A] FIG. 4A is an enlarged perspective view illustrating an example of the configuration of the position detection device illustrated in FIG. [Figure 4B] FIG. 4B is a schematic diagram for explaining the positional relationship between the first magnet and the magnetic sensor shown in FIG. [Figure 5A] FIG. 5A is an enlarged perspective view of a portion of the drive device shown in FIG. [Figure 5B] 1. FIG. 5B is an enlarged perspective view of another part of the drive device shown in FIG. [Figure 6A] FIG. 6A is an enlarged side view of a portion of the drive device shown in FIG. [Figure 6B]1. FIG. 6B is an enlarged side view of another part of the drive device shown in FIG. [Figure 7] FIG. 7 is a perspective view that typically illustrates the first magnetic field and the second magnetic field applied to the magnetic sensor illustrated in FIG. [Figure 8] FIG. 8 is a circuit diagram showing a circuit configuration of the magnetic sensor in the position detection device shown in FIG. [Figure 9] FIG. 9 is a characteristic diagram showing an output voltage characteristic obtained from the magnetic sensor shown in FIG. [Figure 10] FIG. 10 is a perspective view showing a part of one resistor portion in FIG. [Figure 11A] FIG. 11A is a characteristic diagram showing a change in the strength of the magnetic field applied to the magnetic sensor accompanying the movement of the first magnet in the imaging device shown in FIG. [Figure 11B] FIG. 11B is a characteristic diagram showing a change in output voltage obtained from the magnetic sensor accompanying the movement of the first magnet in the imaging device shown in FIG. [Figure 11C] FIG. 11C is a characteristic diagram showing the change in angle of the composite magnetic field of the first magnet and second magnet relative to the stroke amount of the first magnet. [Figure 12A] FIG. 12A is an enlarged perspective view showing an example of the configuration of a position detector having a magnet as a reference example. [Figure 12B] FIG. 12B is a schematic diagram for explaining the positional relationship between the magnet and the magnetic sensor in the position detection device as the reference example shown in FIG. 12A. [Figure 13] FIG. 13 is an explanatory diagram for explaining linearity error in the position detection device shown in FIG. [Figure 14] FIG. 14 is a perspective view illustrating an overall configuration of a distance measuring device according to an embodiment of the present technology. [Figure 15] FIG. 15 is a perspective view showing the overall configuration of a position detection device mounted on the distance measuring device shown in FIG. [Figure 16A] FIG. 16A is an enlarged perspective view illustrating a portion of the position detection device illustrated in FIG. [Figure 16B]FIG. 16B is a plan view showing the positional relationship between the magnet and the magnetic sensor shown in FIG. 16A. [Figure 17A] FIG. 17A is an enlarged perspective view showing a part of a position detection device as a reference example. [Figure 17B] FIG. 17B is a plan view showing the positional relationship between the magnet and the magnetic sensor shown in FIG. 17A. [Figure 18] FIG. 18 is an enlarged perspective view showing a part of a position detection device as a modified example mounted on the distance measuring device shown in FIG. [Figure 19] FIG. 19 is an enlarged perspective view showing a part of a position detection device as a reference example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The description will be given in the following order. 1. First embodiment 1 is an example of an imaging device including a lens module having a position detection device having a multi-pole magnet and a magnetic sensor. 2. Second embodiment Example of a distance measuring device equipped with a position detection device 3. Variations

[0012] <1. First embodiment> [Configuration of imaging device 100] First, the configuration of an imaging device 100 according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG.

[0013] FIG. 1 is a perspective view showing an example of the overall configuration of an imaging device 100. FIG. 2 is an explanatory diagram showing a schematic view of the inside of the imaging device 100 as viewed from the side. FIG. 3 is an explanatory diagram showing a schematic view of the inside of the imaging device 100 as viewed from the subject side. Note that the dimensions and arrangement positions of the components of the imaging device 100 do not necessarily match in FIGS. 1 to 3. Also, the imaging device 100 shown in FIGS. 1 to 3 is merely an example, and in this embodiment, the components constituting the imaging device 100 and their dimensions, shapes and arrangement positions are not limited to those shown in FIGS. 1 to 3.

[0014] The imaging device 100 constitutes, for example, a part of a camera for a smartphone equipped with an optical image stabilization mechanism and an autofocus mechanism. The imaging device 100 includes, for example, an image sensor 200 as an imaging element that acquires an image using a CMOS or the like, and a lens module 300 that guides light from a subject to the image sensor 200.

[0015] [Configuration of lens module 300] The lens module 300 includes a position detection device 1 according to an embodiment of the present technology, a driving device 3, a lens 5, a housing 6, and a substrate 7. The position detection device 1 is a magnetic position detection device, and is a mechanism for detecting the position of the lens 5 when automatically focusing incident light so that light incident from a subject (hereinafter simply referred to as incident light) is imaged on the imaging surface of the image sensor 200. The driving device 3 is a mechanism for driving the lens 5 to focus the incident light. The housing 6 houses the position detection device 1, the driving device 3, and the like, and protects them. The substrate 7 has an upper surface 7A. Note that the housing 6 is omitted in FIG. 2.

[0016] Here, the X-axis, the Y-axis, and the Z-axis are defined as shown in FIG. 1 to FIG. 3, respectively. The X-axis, the Y-axis, and the Z-axis are mutually orthogonal. In this embodiment, the X-axis is perpendicular to the upper surface 7A of the substrate 7, and the Y-axis and the Z-axis are both parallel to the upper surface 7A of the substrate 7. Furthermore, in this embodiment, the +X direction is the upward direction, and the -X direction is the downward direction. Moreover, the +Z direction and the -Z direction in this embodiment, that is, the direction parallel to the Z-axis, are specific examples corresponding to the "first axis direction" in one embodiment of the present technology. The +X direction and the -X direction in this embodiment, that is, the direction parallel to the X-axis, are specific examples corresponding to the "second axis direction" in one embodiment of the present technology. Furthermore, the +Y direction and the -Y direction in this embodiment, that is, the direction parallel to the Y-axis, are specific examples corresponding to the "third axis direction" in one embodiment of the present technology.

[0017] (Lens 5) The lens 5 is disposed above the upper surface 7A of the substrate 7 in such a position that the optical axis direction of the lens 5 coincides with the X-axis. As shown in Fig. 2, the substrate 7 has an opening 7K that passes light that has passed through the lens 5. As shown in Fig. 2, the lens module 300 is aligned with the image sensor 200 so that light from a subject that has passed through the lens 5 and the opening 7K of the substrate 7 in that order is incident on the image sensor 200.

[0018] (Position detection device 1) Next, the position detection device 1 according to the present embodiment will be described in detail.

[0019] The position detection device 1 has a first holding member 14 (see FIG. 2), a second holding member 15, a plurality of wires 16, and a plurality of springs 17. The first holding member 14 holds a first magnet 10 (described later) and a lens 5. The first holding member 14 has, for example, a cylindrical shape configured so that the lens 5 can be attached thereto. It is noted that the position detection device 1 does not necessarily have to have the wires 16 and the springs 17.

[0020] The first holding member 14 is provided so as to be movable relative to the second holding member 15 along the optical axis direction of the lens 5, i.e., along the X-axis direction. In this embodiment, the second holding member 15 has, for example, a box-like shape configured so as to be able to accommodate the lens 5 and the first holding member 14 therein. A plurality of springs 17 connect the first holding member 14 and the second holding member 15, and support the first holding member 14 so that the first holding member 14 can move relative to the second holding member 15 in the X-axis direction.

[0021] The second holding member 15 is provided above the upper surface 7A of the substrate 7 so as to be movable in both the Y-axis direction and the Z-axis direction relative to the substrate 7. A plurality of wires 16 connect the substrate 7 and the second holding member 15 and support the second holding member 15 so that the second holding member 15 can move in the Y-axis direction and the Z-axis direction relative to the substrate 7. When the relative position of the second holding member 15 with respect to the substrate 7 changes, the relative position of the first holding member 14 with respect to the substrate 7 also changes.

[0022] The position detection device 1 further includes a first magnet 10 as a first magnetic field generating unit that generates a first magnetic field MF1, and a magnetic sensor 20. Therefore, the first magnetic field MF1 is a magnetic field formed by the first magnet 10. The first magnetic field MF1 includes a magnetic field component Hsx along the X-axis direction and a magnetic field component Hsy along the Y-axis direction. The first magnet 10 is held by a first holding member 14, and is provided so that its relative position with respect to the second magnets 31, 32 as a second magnetic field generating unit that generates a second magnetic field MF2 can be changed. In addition, the magnetic sensor 20 and the first magnet 10 are provided so as to be relatively movable along the X-axis direction while maintaining a state in which they overlap each other in the Z-axis direction. The first magnet 10 has an exterior appearance of a substantially rectangular parallelepiped shape with the X-axis direction as a longitudinal direction, for example. The first magnet 10 is mainly composed of a first magnetic material. For example, a neodymium-based magnetic material such as NdFeB can be used as the first magnetic material. In one embodiment, the first magnetic material may be NdFeB of grade N48SH. Alternatively, the first magnetic material may be SmCo. The first magnet 10 is a position detection magnet that generates a first magnetic field MF1 for detecting the position of the first holding member 14 that holds the lens 5.

[0023] Moreover, the first magnet 10 is fixed to the first holding member 14 so as to be located between the second magnets 31 and 32 in the Y-axis direction. That is, the first magnet 10 is held by the first holding member 14. When the relative position of the second holding member 15 with respect to the first holding member 14 changes along the X-axis direction, the relative positions of the second magnets 31, 32 with respect to the first magnet 10 also change along the X-axis direction.

[0024] The magnetic sensor 20 detects a resultant magnetic field MF as a magnetic field to be detected at a predetermined detection position where the magnetic sensor 20 is disposed, and generates a detection signal corresponding to the direction of the resultant magnetic field MF. The magnetic sensor 20 is located between the second magnets 31 and 32 in the Y-axis direction, and is located on the opposite side of the lens 5 in the Z-axis direction, sandwiching the first magnet 10 therebetween. The magnetic sensor 20 is fixed to the second holding member 15 together with the second magnets 31 and 32. Therefore, the first magnet 10 is configured to be movable in the X-axis direction relative to the magnetic sensor 20.

[0025] In this embodiment, the predetermined detection position is the position where the magnetic sensor 20 is disposed. As described above, when the position of the first magnet 10 as the first magnetic field generating unit in the X-axis direction changes relative to the positions of the second magnets 31 and 32 as the second magnetic field generating unit, the distance between the predetermined detection position and the first magnet 10 changes. The magnetic field to be detected is the synthetic magnetic field MF of the first magnetic field MF1 and the second magnetic field MF2 at the detection position. Since the magnetic sensor is close to the first magnetic field generating unit, the synthetic magnetic field MF is mainly derived from the first magnetic field MF1. Depending on the arrangement, there may be cases where the second magnetic field MF2 becomes almost 0. The magnetic sensor 20 generates a detection signal corresponding to the direction of the synthetic magnetic field MF, and can detect the change in the position of the first magnet 10, that is, the change in the position of the lens 5.

[0026] FIG. 4A is an enlarged perspective view of the first magnet 10 and the magnetic sensor 20 in the position detection device 1. FIG. 4B is a schematic diagram showing an example of the state in which the magnetic sensor 20 and the first magnet 10 are viewed in the -X direction. As described above, the first magnet 10 is provided so as to be movable in the X-axis direction relative to the magnetic sensor 20. As shown in FIG. 4A and FIG. 4B, the first magnet 10 is disposed so as to face the magnetic sensor 20 at a distance in the Z-axis direction, for example. The first magnet 10 is a multi-pole magnet including a plurality of N poles 11N, 12N and a plurality of S poles 11S, 12S. Here, the N pole 11N and the S pole 11S are adjacent to each other in the Z-axis direction. The N pole 12N and the S pole 12S are adjacent to each other in the Z-axis direction. The first magnet 10 includes, for example, a first region portion 11, a second region portion 12, and a neutral zone 13. The first region portion 11 is magnetized in, for example, the -Z direction, and the second region portion 12 is magnetized in the +Z direction opposite to the -Z direction. The neutral zone 13 is sandwiched between the first region portion 11 and the second region portion 12 in the X-axis direction. In FIG. 4A, the arrows drawn on the first region portion 11 and the second region portion 12 respectively represent the directions of the magnetic fields of the first region portion 11 and the second region portion 12. The first region portion 11 and the second region portion 12 are adjacent to each other across the neutral zone 13 in the X-axis direction, which is the movement direction of the first magnet 10. The first region portion 11 includes an N pole 11N and an S pole 11S adjacent to each other along the Z-axis direction. The second region portion 12 includes an N pole 12N and an S pole 12S adjacent to each other along the Z-axis direction. Here, the north pole 11N and the south pole 12S are arranged adjacent to each other in the X-axis direction with the neutral zone 13 in between, and the north pole 12N and the south pole 11S are arranged adjacent to each other in the X-axis direction with the neutral zone 13 in between.

[0027] The neutral zone 13 extends, for example, along the YZ plane. The neutral zone 13 is a non-magnetized portion of the first magnet 10 that is not magnetized.

[0028] 4A and 4B, a boundary 11K between an N pole 11N and an S pole 11S adjacent in the Z-axis direction, and a boundary 12K between an N pole 12N and an S pole 12S adjacent in the Z-axis direction, both extend along, for example, an XY plane. Here, a center position P20 of the magnetic sensor 20 in the Y-axis direction is different from a center position P10 of the first magnet 10 in the Y-axis direction. Although FIG. 4B illustrates an example in which the center position P20 is shifted in the +Y direction from the center position P10, the center position P20 may be shifted in the -Y direction from the center position P10.

[0029] In one embodiment, the length 10Z of the first magnet 10 in the Z-axis direction may be smaller than the length 10Y of the first magnet 10 in the Y-axis direction. Also, at least a part of the magnetic sensor 20 and at least a part of the first magnet 10 may overlap in the Z-axis direction. By selecting such a configuration, the position detection device 1 can be made smaller and lighter, while the first magnetic field MF1 can be effectively applied to the magnetic sensor 20.

[0030] (Driver 3) Next, the driving device 3 according to this embodiment will be described in detail.

[0031] The driving device 3 has two second magnets 31, 32 arranged at different positions spaced apart from each other as a second magnetic field generating unit that generates a second magnetic field MF2. The second magnets 31, 32 are fixed to a second holding member 15. Therefore, the second magnets 31, 32 are configured not to move relative to the magnetic sensor 20. The first magnet 10 as a first magnetic field generating unit is provided so as to be movable along the X-axis direction relative to the magnetic sensor 20 and the second magnets 31, 32 as a second magnetic field generating unit.

[0032] 1 to 3, the second magnet 31 is located in the +Y direction as seen from the lens 5. The second magnet 32 ​​is located in the -Y direction as seen from the lens 5. That is, in the driving device 3, the second magnets 31 and 32 are each disposed on two opposing sides of four sides that form a square or rectangular area along the upper surface 7A of the substrate 7, for example.

[0033] The second magnet 31 and the second magnet 32 ​​have, for example, a substantially rectangular parallelepiped shape with the Z-axis direction as the longitudinal direction. The second magnet 31 and the second magnet 32 ​​are arranged to face each other with the lens 5 in between in the Y-axis direction perpendicular to the Z-axis direction. The second magnetic field MF2 is a magnetic field in which the magnetic fields generated by the second magnet 31 and the second magnet 32 ​​are synthesized, and includes a magnetic field component Hdx along the X-axis direction and a magnetic field component Hdy along the Y-axis direction. The second magnet 31 and the second magnet 32 ​​are mainly composed of a second magnetic material. As the second magnetic material, for example, a neodymium-based magnetic material such as NdFeB can be mentioned. In one embodiment, the second magnetic material can be NdFeB of grade N48H. The second magnet 31 and the second magnet 32 ​​are fixed to the second holding member 15. That is, the second magnetic field generating unit is held by the second holding member 15. The second magnets 31 and 32 are driving magnets that generate a driving force for moving the first holding member 14 that holds the lens 5 along the Z axis. Furthermore, the second magnets 31 and 32 may be bias magnets for applying a bias magnetic field to the magnetic sensor 20.

[0034] Fig. 5A is an enlarged perspective view showing the vicinity of the second magnet 31 of the driving device 3. Fig. 5B is an enlarged perspective view showing the vicinity of the second magnet 32 ​​of the driving device 3. As shown in Figs. 5A and 5B, both the second magnet 31 and the second magnet 32 ​​may be, for example, multi-pole magnets.

[0035] As shown in FIG. 5A, the second magnet 31 includes a first region 311 magnetized in, for example, the +Y direction, a second region 312 magnetized in, for example, the -Y direction, and a neutral zone 313 sandwiched between the first region 311 and the second region 312. In FIG. 5A, the arrows drawn on the first region 311 and the second region 312 respectively indicate the magnetization directions of the first region 311 and the second region 312. The first region 311 and the second region 312 each have, for example, a substantially rectangular parallelepiped shape with the Z-axis direction as the longitudinal direction. The first region 311 and the second region 312 are adjacent to each other in the X-axis direction with the neutral zone 313 sandwiched therebetween. The first region 311 includes an N pole 311N and an S pole 311S adjacent to each other along the Y-axis direction. The second region portion 312 includes an N pole 312N and an S pole 312S adjacent to each other along the Y-axis direction. Here, the N pole 311N and the S pole 312S are arranged adjacent to each other in the X-axis direction with the neutral zone 313 in between, and the N pole 312N and the S pole 311S are arranged adjacent to each other in the X-axis direction with the neutral zone 313 in between.

[0036] As shown in FIG. 5B, the second magnet 32 ​​includes a first region 321 magnetized in, for example, the -Y direction, a second region 322 magnetized in the +Y direction, and a neutral zone 323 sandwiched between the first region 321 and the second region 322. In FIG. 5B, the arrows drawn on the first region 321 and the second region 322 respectively indicate the magnetization directions of the first region 321 and the second region 322. The first region 321 and the second region 322 each have, for example, a substantially rectangular parallelepiped shape with the Z-axis direction as the longitudinal direction. The first region 321 and the second region 322 are adjacent to each other in the X-axis direction with the neutral zone 323 sandwiched therebetween. The first region 321 includes an N pole 321N and an S pole 321S adjacent to each other along the Y-axis direction. The second region portion 322 includes an N pole 322N and an S pole 322S adjacent to each other along the Y-axis direction. Here, the N pole 321N and the S pole 322S are arranged adjacent to each other in the X-axis direction with the neutral zone 323 in between, and the N pole 322N and the S pole 321S are arranged adjacent to each other in the X-axis direction with the neutral zone 323 in between.

[0037] In addition to the second magnets 31 and 32, the drive device 3 further includes coils 41, 42, 45, and .

[0038] 1 and 2, coil 41 is disposed between second magnet 31 and substrate 7, and coil 42 is disposed between second magnet 32 ​​and substrate 7. Furthermore, coil 45 is disposed between second magnet 31 and lens 5, and coil 46 is disposed between second magnet 32 ​​and lens 5. Coils 41 and 42 are each fixed to substrate 7. Coils 45 and 46 are each fixed to first holding member 14.

[0039] The magnetic field generated mainly from the second magnet 31 is applied to the coil 41. The magnetic field generated mainly from the second magnet 32 ​​is applied to the coil .

[0040] 2, the coil 45 includes a first conductor portion 45A extending along the first region 311 of the second magnet 31, and a second conductor portion 45B extending along the second region 312 of the second magnet 31. The coil 46 includes a first conductor portion 46A extending along the first region 321 of the second magnet 32, and a second conductor portion 46B extending along the second region 322 of the second magnet 32, as shown in FIG.

[0041] FIG. 6A is an enlarged side view of the second magnet 31 and the coil 45 of the driving device 3. FIG. 6B is an enlarged side view of the second magnet 32 ​​and the coil 46 of the driving device 3. As shown in FIG. 6A, the first conductor 45A of the coil 45 is mainly applied with the +Y-direction component of the magnetic field generated from the first region 311 of the second magnet 31. The second conductor 45B of the coil 45 is mainly applied with the -Y-direction component of the magnetic field generated from the second region 312 of the second magnet 31. As shown in FIG. 6B, the first conductor 46A of the coil 46 is mainly applied with the -Y-direction component of the magnetic field generated from the first region 321 of the second magnet 32. The second conductor 46B of the coil 46 is mainly applied with the +Y-direction component of the magnetic field generated from the second region 322 of the second magnet 32.

[0042] 6A and 6B, the driving device 3 further includes a magnetic sensor 30A and a magnetic sensor 30B. The magnetic sensors 30A and 30B are used when changing the position of the lens 5 to reduce the effect of camera shake.

[0043] The magnetic sensor 30A located inside the coil 41 detects the magnetic field generated from the second magnet 31 and generates a signal corresponding to the position of the second magnet 31. The magnetic sensor 30B located inside the coil 42 detects the magnetic field generated from the second magnet 32 ​​and generates a signal corresponding to the position of the second magnet 32. The magnetic sensors 30A and 30B can be configured by elements that detect magnetic fields, such as magnetoresistance effect elements and Hall elements. The driving device 3 may have only one of the magnetic sensor 30A located inside the coil 41 or the magnetic sensor 30B located inside the coil 42.

[0044] Fig. 7 is a partial perspective view showing the position detection device 1. In Fig. 7, an arrow labeled MF1 represents the first magnetic field MF1 that reaches the magnetic sensor 20. As described above, the first magnetic field MF1 includes a magnetic field component Hsx along the X-axis direction and a magnetic field component Hsy along the Y-axis direction.

[0045] Next, the configuration of the magnetic sensor 20 will be described with reference to Fig. 8. Fig. 8 is a circuit diagram showing the configuration of the magnetic sensor 20. In this embodiment, the magnetic sensor 20 is configured to generate a detection signal corresponding to the direction of the synthetic magnetic field MF, which is the magnetic field to be detected, corresponding to the angle that the direction of the synthetic magnetic field MF makes with respect to a reference direction.

[0046] As shown in FIG. 8, the magnetic sensor 20 has a Wheatstone bridge circuit 21. The Wheatstone bridge circuit 21 includes a power supply port V, a ground port G, two output ports E1 and E2, a first resistor unit R1 and a second resistor unit R2 connected in series, and a third resistor unit R3 and a fourth resistor unit R4 connected in series. A first end of the first resistor unit R1 and a first end of the third resistor unit R3 are each connected to the power supply port V. A second end of the first resistor unit R1 is each connected to a first end of the second resistor unit R2 and the output port E1. A second end of the third resistor unit R3 is each connected to a first end of the fourth resistor unit R4 and the output port E2. A second end of the second resistor unit R2 and a second end of the fourth resistor unit R4 are each connected to the ground port G. A power supply voltage of a predetermined magnitude is applied to the power supply port V. The ground port G is connected to ground. The output ports E1 and E2 are each connected to the control unit 4 (FIG. 1).

[0047] In this embodiment, each of the first to fourth resistance parts R1 to R4 includes a plurality of magnetoresistance effect elements (MR elements) connected in series. Each of the plurality of MR elements may be, for example, a spin-valve type MR element. This spin-valve type MR element has a magnetization pinned layer whose magnetization direction is fixed, a free layer which is a magnetic layer whose magnetization direction changes according to the direction of the magnetic field to be detected, and a non-magnetic layer disposed between the magnetization pinned layer and the free layer. The spin-valve type MR element may be a tunnel magnetoresistance effect element (TMR element) or a giant magnetoresistance effect element (GMR element). In the TMR element, the non-magnetic layer is a tunnel barrier layer. In the GMR element, the non-magnetic layer is a non-magnetic conductive layer. In the spin-valve type MR element, the resistance value changes according to the angle that the magnetization direction of the free layer makes with respect to the magnetization direction of the magnetization pinned layer, and the resistance value is minimum when this angle is 0°, and maximum when the angle is 180°. In FIG. 8, the solid arrows represent the magnetization direction of the magnetization pinned layer in the MR element, and the hollow arrows represent the magnetization direction of the free layer in the MR element.

[0048] As shown in FIG. 8, the magnetization direction of the magnetization pinned layer in the MR elements included in the first resistor R1 (hereinafter simply referred to as the pin direction of the first resistor R1) is opposite to the magnetization direction of the magnetization pinned layer in the MR elements included in the second resistor R2 (hereinafter simply referred to as the pin direction of the second resistor R2). In addition, the magnetization direction of the magnetization pinned layer in the MR elements included in the third resistor R3 (hereinafter simply referred to as the pin direction of the third resistor R3) is opposite to the magnetization direction of the magnetization pinned layer in the MR elements included in the fourth resistor R4 (hereinafter simply referred to as the pin direction of the fourth resistor R4). Furthermore, the pin direction of the first resistor R1 and the pin direction of the second resistor R2 are perpendicular to the pin direction of the third resistor R3 and the pin direction of the fourth resistor R4. Therefore, for example, as shown in FIG. 9, when the voltage Vout1 output to the output port E1 describes a cosine curve that changes according to the angle θ of the direction of the composite magnetic field MF relative to the reference direction, the voltage Vout2 output to the output port E2 describes a sine curve that changes according to the angle θ. That is, the voltages Vout1 and Vout2 have a phase difference of 90° with respect to the angle θ. A signal corresponding to the potential difference between the output ports E1 and E2 is output from the differential detector as a detection signal. The detection signal depends on the potential of the output port E1, the potential of the output port E2, and the potential difference between the output ports E1 and E2. The detection signal changes according to the direction of the composite magnetic field MF, which is the magnetic field to be detected.

[0049] The magnetization directions of the magnetization fixed layers in the multiple MR elements may be slightly deviated from the above-mentioned directions in terms of the manufacturing accuracy of the MR elements, etc.

[0050] Here, an example of the configuration of the first to fourth resistance sections R1 to R4 will be described with reference to FIG. 10. FIG. 10 is a perspective view showing a part of one resistance section in the magnetic sensor 20 shown in FIG. 8. In this example, one resistance section has a plurality of lower electrodes 162, a plurality of magnetoresistance effect (MR) elements 150, and a plurality of upper electrodes 163. The plurality of lower electrodes 162 are arranged on a substrate not shown. Each of the lower electrodes 162 has an elongated shape. A gap is formed between two lower electrodes 162 adjacent to each other in the longitudinal direction of the lower electrode 162. As shown in FIG. 10, the MR elements 150 are arranged on the upper surface of the lower electrode 162 near both ends in the longitudinal direction. The MR elements 150 include, for example, a magnetization free layer 151, a nonmagnetic layer 152, a magnetization fixed layer 153, and an antiferromagnetic layer 154, which are stacked in this order from the lower electrode 162 side. The magnetization free layer 151 is electrically connected to the lower electrode 162. The antiferromagnetic layer 154 is configured to include an antiferromagnetic material, and generates exchange coupling between the magnetization fixed layer 153 and the magnetization fixed layer 153 to fix the magnetization direction of the magnetization fixed layer 153. The multiple upper electrodes 163 are arranged on the multiple MR elements 150. Each upper electrode 163 has an elongated shape, and is arranged on two lower electrodes 162 adjacent to each other in the longitudinal direction of the lower electrode 162 to electrically connect the antiferromagnetic layers 154 of the two adjacent MR elements 150 to each other. With this configuration, the resistance unit shown in FIG. 10 has multiple MR elements 150 connected in series by the multiple lower electrodes 162 and the multiple upper electrodes 163. Note that the arrangement of the magnetization free layer 151, the nonmagnetic layer 152, the magnetization fixed layer 153, and the antiferromagnetic layer 154 in the MR element 150 may be upside down from the arrangement shown in FIG. 10.

[0051] Next, the operation of the driving device 3 will be described with reference to Fig. 1 to Fig. 6B. First, the optical image stabilization mechanism and the autofocus mechanism will be briefly described. The driving device 3 constitutes a part of the optical image stabilization mechanism and the autofocus mechanism. The driving device 3, the optical image stabilization mechanism, and the autofocus mechanism are controlled by a control unit 4 (see Fig. 1) provided outside the imaging device 100. The control unit 4 has a circuit composed of, for example, a CPU (Central Processing Unit) which is an arithmetic processing device, a ROM (Read Only Memory) which is a storage element for storing programs and arithmetic parameters used by the CPU, and a RAM (Random Access Memory) which is a storage element for temporarily storing parameters that change appropriately during execution of the CPU.

[0052] The optical image stabilization mechanism is configured to detect camera shake, for example, by a gyro sensor or the like external to the imaging device 100. When the optical image stabilization mechanism detects camera shake, the control unit 4 controls the drive device 3 so that the relative position of the lens 5 with respect to the substrate 7 changes according to the type of camera shake. This makes it possible to stabilize the absolute position of the lens 5 and reduce the effects of camera shake. Note that the relative position of the lens 5 with respect to the substrate 7 changes in a direction parallel to the Y axis or a direction parallel to the Z axis according to the type of camera shake.

[0053] The autofocus mechanism is configured to detect a state in which a subject is in focus by, for example, the image sensor 200 or an autofocus sensor. The control unit 4 changes the relative position of the lens 5 with respect to the substrate 7 along the X-axis by the drive device 3 so that the subject is in focus. This allows automatic focusing on the subject.

[0054] Next, the operation of the driving device 3 related to the optical image stabilization mechanism will be described. When the control unit 4 applies a current to the coils 41, 42, the second holding member 15 to which the second magnets 31, 32 are fixed moves along the Y axis due to the interaction between the magnetic field generated by the second magnets 31, 32 and the magnetic field generated by the coils 41, 42. As a result, the lens 5 also moves along the Y axis. The control unit 4 detects the position of the lens 5 by measuring signals corresponding to the positions of the second magnets 31, 32 generated by the magnetic sensors 30A, 30B.

[0055] Next, the operation of the driving device 3 related to the autofocus mechanism will be described. When the relative position of the lens 5 with respect to the substrate 7 is moved along the X-axis, the control unit 4 passes a current through the coil 45 so that a current flows in the +Y direction through the first conductor portion 45A and a current flows in the -Y direction through the second conductor portion 45B. The control unit 4 further passes a current through the coil 46 so that a current flows in the -Y direction through the first conductor portion 46A and a current flows in the +Y direction through the second conductor portion 46B. These currents and the magnetic field generated by the second magnets 31 and 32 cause a Lorentz force in the +X direction to act on the first conductor portion 45A and the second conductor portion 45B of the coil 45 and the first conductor portion 46A and the second conductor portion 46B of the coil 46. As a result, the first holding member 14 to which the coils 45 and 46 are fixed moves in the +X direction. As a result, the lens 5 also moves in the +X direction.

[0056] When the relative position of the lens 5 with respect to the substrate 7 is moved in the -X direction, the control unit 4 causes a current to flow through the coils 45 and 46 in the opposite direction to that when the lens 5 is moved in the +X direction.

[0057] [Functions and Effects of the Imaging Device 100] Next, the operation and effect of the position detection device 1 according to the present embodiment and the imaging device 100 including the same will be described. The position detection device 1 according to the present embodiment is used to detect the position of the lens 5. In this embodiment, when the relative position of the lens 5 to the substrate 7 changes, the relative position of the first holding member 14 to the substrate 7 and the second holding member 15 also changes. As described above, the first holding member 14 holds the first magnet 10 as the first magnetic field generating unit and the lens 5, and the second holding member 15 holds the second magnets 31 and 32 as the second magnetic field generating unit and the magnetic sensor 20. Therefore, when the relative position of the lens 5 changes as described above, the relative position of the first magnet 10 to the second magnets 31 and 32 and the magnetic sensor 20 changes. In this embodiment, the direction of change in the relative position of the first magnet 10 to the second magnets 31 and 32 and the magnetic sensor 20 is the optical axis direction of the lens 5, that is, the direction parallel to the X-axis.

[0058] While the relative position of the first magnet 10 to the second magnets 31, 32 and the magnetic sensor 20 changes, the relative position of the second magnets 31, 32 to the magnetic sensor 20 does not change. Therefore, when the relative position of the first magnet 10 to the second magnets 31, 32 and the magnetic sensor 20 changes, the strength and direction of the second magnetic field MF2 does not change, but the strength and direction of the first magnetic field MF1 changes. When the strength and direction of the first magnetic field MF1 change, the direction and strength of the composite magnetic field MF also change, and the value of the detection signal generated by the magnetic sensor 20 changes accordingly. That is, the value of the detection signal generated by the magnetic sensor 20 changes depending on the relative position of the first magnet 10 to the substrate 7. The control unit 4 is configured to obtain the angle θ of the direction of the composite magnetic field MF by performing arithmetic processing from the detection signal of the magnetic sensor 20 that changes with the magnetic field component Hsx along the X-axis direction and the magnetic field component Hsy along the Y-axis direction. The relative position of the first magnet 10 with respect to the substrate 7 represents the relative position of the lens 5 with respect to the substrate 7 .

[0059] As described above, the magnetic sensor 20 has a Wheatstone bridge circuit 21 including, for example, the first to fourth resistor parts R1 to R4, and the pin directions of the first to fourth resistor parts R1 to R4 are anti-parallel to each other or perpendicular to each other. Therefore, the magnetic sensor 20 can detect, for example, the magnetic field Hx in the X-axis direction and the magnetic field Hy in the Y-axis direction of the composite magnetic field MF.

[0060] The angle θ of the direction of the resultant magnetic field MF is defined by the following equation (1). θ=arctan2(Hsx+Hdx,Hsy+Hdy) …(1) Here, Hsx is the magnetic field component of the first magnetic field MF1 along the X-axis direction, Hdx is the magnetic field component of the second magnetic field MF2 along the X-axis direction, Hsy is the magnetic field component of the first magnetic field MF1 along the Y-axis direction, and Hdy is the magnetic field component of the second magnetic field MF2 along the Y-axis direction.

[0061] Here, the magnetic field components Hdx and Hdy reaching the magnetic sensor 20 are extremely weak compared to the magnetic field components Hsx and Hsy reaching the magnetic sensor 20. Therefore, the magnetic field components Hdx and Hdy can be substantially ignored when determining the angle θ of the direction of the synthetic magnetic field MF, and therefore the angle θ of the direction of the synthetic magnetic field MF reaching the magnetic sensor 20 can be expressed by equation (2). θ ≒ arctan2(Hsx, Hsy) … (2)

[0062] That is, the angle θ varies depending on the magnetic field component Hsx and the magnetic field component Hsy.

[0063] In the imaging device 100, as the first magnet 10 moves along the X-axis direction relative to the magnetic sensor 20, a first magnetic field MF1 including a magnetic field component Hsx along the X-axis direction and a magnetic field component Hsy along the Y-axis direction that change as shown in FIG. 11A is applied to the magnetic sensor 20. At this time, the magnetic sensor 20 detects voltages Vout1 and Vout2 that change as shown in FIG. 11B. In FIG. 11A, the horizontal axis represents the position (stroke amount) [μm] of the first magnet 10 relative to the reference position, and the vertical axis represents the magnetic field strength [mT] detected by the magnetic sensor 20. In FIG. 11B, the horizontal axis represents the position (stroke amount) [μm] of the first magnet 10 relative to the reference position, and the vertical axis represents the voltage [mV / V] output from the magnetic sensor 20. The control unit 4 treats the voltages Vout1 and Vout2 as a cosine curve (V×cosθ+V / 2) and a sine curve (V×sinθ+V / 2) for the angle θ of the direction of the composite magnetic field MF, respectively, and calculates the angle θ that changes according to the position of the first magnet 10 in the X-axis direction according to θ[deg.]=arctan(T×(V×sinθ) / (V×cosθ)) (see FIG. 11C). In FIG. 11C, the horizontal axis represents the position (stroke amount) [μm] of the first magnet 10 relative to the reference position in the X-axis direction, and the vertical axis represents the angle θ [deg.]. As shown in FIG. 11C, the angle θ changes almost linearly with respect to the stroke amount of the first magnet 10. Therefore, by determining the angle θ, the position (stroke amount) of the first magnet 10 in the X-axis direction is uniquely determined. Note that the constant T in the above formula is a correction factor for improving linearity.

[0064] In this way, according to the position detection device 1 of the present embodiment, the first magnet 10, which is movable in the X-axis direction while facing the magnetic sensor 20 at a distance in the Z-axis direction, is a multi-pole magnet. Therefore, the magnetic field component Hsx in the X-axis direction and the magnetic field component Hsy in the Y-axis direction having a phase difference (for example, a phase difference of 90°) can be applied to the magnetic sensor 20. Furthermore, in the position detection device 1, the center position P20 of the magnetic sensor 20 in the Y-axis direction is made different from the center position P10 of the first magnet 10 in the Y-axis direction. Therefore, the magnetic field component Hsx is sufficiently applied to the magnetic sensor 20. Therefore, according to the position detection device 1 of the present embodiment, the angle θ of the composite magnetic field MF according to the stroke amount of the first magnet 10 can be detected with high accuracy using the magnetic field component Hsx and the magnetic field component Hsy detected by the magnetic sensor 20.

[0065] Here, the strength of the magnetic field component Hsx and the strength of the magnetic field component Hsy vary depending on the distance between the first magnet 10 and the magnetic sensor 20. However, by calculating the angle θ by the angle calculation using the ratio between the voltage Vout1 corresponding to the strength of the magnetic field component Hsx and the voltage Vout2 corresponding to the strength of the magnetic field component Hsy, the influence of the variation in the distance between the first magnet 10 and the magnetic sensor 20 on the angle θ can be reduced. In addition, in the position detection device 1, the angle θ of the composite magnetic field MF is calculated by the angle calculation using the ratio between the voltage Vout1 corresponding to the strength of the magnetic field component Hsx and the voltage Vout2 corresponding to the strength of the magnetic field component Hsy, so that the deterioration of the detection accuracy of the stroke amount of the first magnet 10 due to the change in the environmental temperature can be suppressed. In general, the strength of the magnetic field formed by the magnet also varies with the rise and fall of the temperature, but the temperature dependency of the strength of the magnetic field component Hsx in the first magnet 10 and the temperature dependency of the strength of the magnetic field component Hsy in the first magnet 10 coincide with each other. For this reason, by using the ratio between the intensity of the magnetic field component Hsx and the intensity of the magnetic field component Hsy, the calculated angle θ becomes almost constant regardless of the environmental temperature. Therefore, according to the position detection device 1, the stroke amount of the first magnet 10 can be accurately calculated from the angle θ calculated from the magnetic field component Hsx and the magnetic field component Hsy.

[0066] Next, in order to clarify the technical significance of the present technology, a position detection device 101 will be described as a reference example in which a magnet 110 having a plurality of regions magnetized in the Y-axis direction as shown in FIG. 12A and FIG. 12B is used instead of the first magnet 10, and the stroke amount of the magnet 110 is calculated. The configuration of the position detection device 101 of this reference example is the same as that of the position detection device 1 of this embodiment, except that the magnet 110 is used instead of the first magnet 10. FIG. 12A is a perspective view that typically shows the position detection device 101 as a reference example, and corresponds to FIG. 4A that shows the position detection device 1 of this embodiment. FIG. 12B is a top view that typically shows the position detection device 101 as a reference example, and corresponds to FIG. 4B that shows the position detection device 1 of this embodiment. The magnet 110 includes a first region portion 111, a second region portion 112, and a neutral zone 113. The first region portion 111 is magnetized in the +Y direction and includes an N pole 111N and an S pole 111S adjacent to each other in the Y-axis direction. The second region portion 112 is magnetized in the -Y direction and includes an N pole 112N and an S pole 112S adjacent to each other in the Y-axis direction. The neutral zone 113 is sandwiched between the first region portion 111 and the second region portion 112 in the X-axis direction. In the magnet 110, the N pole 111N and the S pole 112S are arranged adjacent to each other in the X-axis direction with the neutral zone 113 in between, and the N pole 112N and the S pole 111S are arranged adjacent to each other in the X-axis direction with the neutral zone 113 in between. Furthermore, the magnet 110 has a length 110Y in the Y-axis direction and a length 110Z in the Z-axis direction. The length 110Y is equal to the length 10Y of the first magnet 10, and the length 110Z is equal to the length 10Z of the first magnet 10. The magnet 110 faces the magnetic sensor 20 in the Z-axis direction. The distance between the magnet 110 and the magnetic sensor 20 is equal to the distance between the first magnet 10 and the magnetic sensor 20. Furthermore, the amount of deviation of the center position P20 from the center position P110 in the Y-axis direction is equal to the amount of deviation of the center position P20 from the center position P10 in the Y-axis direction.

[0067] Table 1 shows the results of simulating the linearity error (Linearity Error) [%] associated with the misalignment between the first magnet 10 and the magnetic sensor 20 in the position detection device 1 shown in FIG. 1 and the like. In Table 1, the offset amount [mm] in the Y-axis direction being +0.1 or +0.2 means that, when a predetermined reference position of the magnetic sensor 20 relative to the first magnet 10 is set to 0 [mm], the magnetic sensor 20 is at a position shifted by 0.1 mm or 0.2 mm in the +Y direction from the reference position relative to the first magnet 10. In addition, the offset amount [mm] in the Y-axis direction being -0.1 or -0.2 means that, when a predetermined reference position of the magnetic sensor 20 relative to the first magnet 10 is set to 0 [mm], the magnetic sensor 20 is at a position shifted by 0.1 mm or 0.2 mm in the -Y direction from the reference position relative to the first magnet 10. Similarly, in Table 1, an offset amount [mm] in the Z-axis direction of +0.1 or +0.2 means that, when a predetermined reference position of the magnetic sensor 20 relative to the first magnet 10 is 0 [mm], the magnetic sensor 20 is located at a position moved by 0.1 mm or 0.2 mm in the +Z direction from the reference position relative to the first magnet 10. An offset amount [mm] in the Z-axis direction of -0.1 or -0.2 means that, when a predetermined reference position of the magnetic sensor 20 relative to the first magnet 10 is 0 [mm], the magnetic sensor 20 is located at a position moved by 0.1 mm or 0.2 mm in the -Z direction from the reference position relative to the first magnet 10.

[0068] The linearity error [%] is calculated using the following formula (3). Linearity error [%]=(ΔV / Vrange)×100 ……(3) 13, within the movement range of the first magnet 10 in the X-axis direction relative to the magnetic sensor 20, ΔV is the difference between a change curve C of the output V of the magnetic sensor 20 from position P1 where the output V of the magnetic sensor 20 is at its minimum value Vmin to position P2 where the output V of the magnetic sensor 20 is at its maximum value Vmax, and a straight line L which is a linear approximation of the change curve C. Also, Vrange is the difference between the maximum value Vmax and the minimum value Vmin. The linearity error [%] calculated in this way indicates that the lower the numerical value, the smaller the measurement error.

[0069] [Table 1]

[0070] Table 2 shows the results of a simulation of the linearity error [%] associated with the positional deviation between magnet 110 and magnetic sensor 20 in position detection device 101 shown in Figures 12A and 12B. Table 2 has the same meaning as Table 1.

[0071] [Table 2]

[0072] Comparing Table 1 and Table 2, it can be seen that the linearity error of the position detection device 1 is smaller than that of the position detection device 101. In particular, there is a tendency for the linearity error of the position detection device 101 to increase as the absolute value of the offset amount [mm] in the Y-axis direction increases.

[0073] Thus, in this embodiment, the first magnet 10, which faces the magnetic sensor 20 at a distance in the Z-axis direction, is a multi-pole magnet that includes multiple N poles and multiple S poles adjacent to each other in the Z-axis direction, thereby achieving higher position detection accuracy.

[0074] <2. Second embodiment> [Configuration of distance measuring device 401] Next, a configuration of a distance measuring device 401 according to a second embodiment of the present technology will be described with reference to Fig. 14 to Fig. 16B. In the above first embodiment, an example in which the position detection device is applied to an imaging device equipped with a lens module has been described, but the position detection device according to an embodiment of the present technology can also be applied to a distance measuring device described below.

[0075] FIG. 14 is a perspective view showing a distance measuring device 401 according to this embodiment.

[0076] 14 is a device that measures the distance to an object by detecting irradiated light, and constitutes, for example, a part of an in-vehicle LIDAR (Light Detection And Ranging). The distance measuring device 401 includes, for example, a photoelectric unit 411 and an optical element 412.

[0077] The photoelectric unit 411 includes an optical element 411A that irradiates light 411LA and a detection element 411B that detects reflected light 411LB from an object. The optical element 412 is, for example, a mirror supported by a support 413. The optical element 412 is inclined with respect to the emission surface of the optical element 411A so as to change the traveling directions of the light 411LA and the reflected light 411LB. The optical element 412 is configured to rotate around a predetermined rotation axis 401J by a driving device.

[0078] [Configuration of position detection device 1A] The distance measuring device 401 further includes a position detection device 1A for detecting the rotational position of the optical element 412. FIG. 15 is a schematic perspective view showing the appearance of the position detection device 1A. The position detection device 1A is a magnetic position detection device, and includes the magnetic sensor 20 described in the first embodiment and a magnetic field generator 403. The magnetic field generator 403 is configured to rotate around a predetermined rotation axis in conjunction with the optical element 412. The magnetic field generator 403 may rotate around the same rotation axis 401J as the optical element 412, or may rotate around a rotation axis different from that of the optical element 412. In this embodiment, for convenience, the optical element 412 and the magnetic field generator 403 are assumed to rotate around the same rotation axis 401J.

[0079] The magnetic field generator 403 is a magnetic scale (rotating scale) in which multiple pairs of north poles and south poles are alternately arranged around a rotating shaft 401J.

[0080] The magnetic field generator 403 has an end surface 403A located at one end in a direction parallel to the rotation axis 401J. Multiple pairs of north and south poles are provided along the end surface 403A. In FIG. 15, for example, the north pole is hatched to facilitate understanding. The magnetic sensor 20 is disposed so as to face the end surface 403A. The strength of the magnetic field component at a reference position, for example, the position where the magnetic sensor 20 is disposed, changes with the rotation of the magnetic field generator 403.

[0081] FIG. 16A is a perspective view showing the positional relationship between the magnet 10A mounted on the magnetic field generator 403 and the magnetic sensor 20 arranged in the vicinity thereof. FIG. 16B is a plan view showing the positional relationship between the magnet 10A and the magnetic sensor 20 in the r-θ plane. The magnet 10A is provided in an annular shape along the end face 403A of the magnetic field generator 403. Note that FIGS. 16A and 16B show an enlarged view of a part of the magnet 10A. Also, in FIGS. 16A and 16B, the Z-axis direction is the extension direction of the rotation axis 401J, the θ direction is the rotation direction of the magnetic field generator 403, and the r direction is the radial direction of the annular magnet 10A. Note that in the r direction, the center position CP20 of the magnetic sensor 20 is located outside (farther from the rotation axis 401J) than the center position CP10 of the magnet 10A.

[0082] The magnet 10A is provided so as to be rotatable in the θ direction relative to the magnetic sensor 20. As shown in FIG. 16A, the magnet 10A is disposed so as to face the magnetic sensor 20 at a distance in the Z-axis direction. The magnet 10A has a curved shape in an r-θ plane perpendicular to the Z-axis direction. The magnet 10A is a multi-pole magnet including a plurality of N poles 11N, 12N and a plurality of S poles 11S, 12S. Here, the N pole 11N and the S pole 11S are adjacent to each other in the Z-axis direction. The N pole 12N and the S pole 12S are adjacent to each other in the Z-axis direction. The magnet 10A includes a first region portion 11, a second region portion 12, and a neutral zone 13. The first region portion 11 is magnetized, for example, in the -Z direction, and the second region portion 12 is magnetized in the +Z direction opposite to the -Z direction. The neutral zone 13 is sandwiched between the first region portion 11 and the second region portion 12 in the θ direction. The first region 11 and the second region 12 are adjacent to each other in the θ direction, which is the rotational movement direction of the magnet 10A, with the neutral zone 13 in between. The first region 11 includes an N pole 11N and an S pole 11S adjacent to each other along the Z axis direction. The second region 12 includes an N pole 12N and an S pole 12S adjacent to each other along the Z axis direction. Here, the N pole 11N and the S pole 12S are arranged adjacent to each other in the θ direction with the neutral zone 13 in between, and the N pole 12N and the S pole 11S are arranged adjacent to each other in the θ direction with the neutral zone 13 in between.

[0083] In the distance measuring device 401 configured as above, an output corresponding to the rotational position of the optical element 412 is generated based on the detection signal generated by the magnetic sensor 20. The rotational position of the optical element 412 corresponds to the rotational position of the magnetic field generator 403.

[0084] Table 3 shows the results of simulation of the linearity error [%] associated with the positional deviation between the magnet 10A and the magnetic sensor 20 in the position detection device 1A shown in FIGS. 16A and 16B.

[0085] [Table 3]

[0086] Table 4 shows the results of simulating the linearity error [%] associated with the positional deviation between the magnet 110A and the magnetic sensor 20 in the position detection device 101A shown in Figs. 17A and 17B as a reference example. Fig. 17A is a perspective view showing the positional relationship between the magnet 110A as a reference example and the magnetic sensor 20 arranged in the vicinity of the magnet 110A. Fig. 17B is a plan view showing the positional relationship between the magnet 110A and the magnetic sensor 20 in the r-θ plane. In the position detection device 101A shown in Figs. 17A and 17B, the magnet 110A is configured to rotate in the θ direction around a rotation axis extending in the Z-axis direction with respect to the magnetic sensor 20, similar to the position detection device 1A. Also, similar to the position detection device 1A, the magnet 110A and the magnetic sensor 20 face each other in the Z-axis direction. However, the N poles 111N, 112N and the S poles 111S, 112S of the magnet 110A are adjacent to each other in the r direction, which is the radial direction of the magnet 110A. That is, the magnetization direction of magnet 110A is the r direction, while the opposing direction of magnet 110A and magnetic sensor 20 is the Z axis direction, and they do not coincide with each other. In position detection device 101A, center position CP20 of magnetic sensor 20 is outside (farther from rotation axis 401J) than center position CP110 of magnet 110A in the r direction.

[0087] [Table 4]

[0088] Comparing Table 3 and Table 4, it can be seen that the linearity error of the position detection device 1A is smaller than that of the position detection device 101A. In particular, there is a tendency for the linearity error of the position detection device 101A to increase as the absolute value of the offset amount [mm] in the Y-axis direction increases.

[0089] [Configuration Example of Position Detection Device 1B as a Modified Example] In the position detection device 1A shown in FIG. 15 and the like, the magnet 10A and the magnetic sensor 20 are arranged to face each other along the rotation axis 401J about which the magnet 10A rotates, but the present technology is not limited to this. For example, as in the position detection device 1B having the magnet 10B as a modified example shown in FIG. 18, the magnet 10B and the magnetic sensor 20 may be arranged to face each other in the r direction, which is the radial direction of the ring-shaped magnet 10B. However, in this case, the magnetization direction of the magnet 10B is also the r direction. That is, in the first region portion 11, the N pole 11N and the S pole 11S are adjacent to each other in the r direction, and in the second region portion 12, the N pole 12N and the S pole 12S are adjacent to each other in the r direction. The magnet 10B has a curved shape in the r-θ plane perpendicular to the Z-axis direction.

[0090] Table 5 shows the results of a simulation of the linearity error (Linearity Error) [%] associated with the positional deviation between the magnet 10B and the magnetic sensor 20 in the position detection device 1B shown in FIG.

[0091] [Table 5]

[0092] Table 6 shows the results of simulating the linearity error [%] associated with the misalignment between the magnet 110B and the magnetic sensor 20 in the position detection device 101B shown in FIG. 19. In the position detection device 101B in FIG. 19, similar to the position detection device 1B, the magnet 110B is configured to rotate in the θ direction around a rotation axis extending in the Z-axis direction with respect to the magnetic sensor 20. Similarly to the position detection device 1B, the magnet 110B and the magnetic sensor 20 face each other in the r-axis direction. However, in the magnet 110B, the N poles 111N and 112N and the S poles 111S and 112S are adjacent to each other in the Z-axis direction, which is the rotation axis direction of the magnet 110B. That is, the magnetization direction of the magnet 110B is the Z-axis direction, while the facing direction of the magnet 110B and the magnetic sensor 20 is the r-direction, and the two do not match.

[0093] [Table 6]

[0094] Comparing Table 5 and Table 6, it can be seen that the linearity error of the position detection device 1B is smaller than that of the position detection device 101B. In particular, there is a tendency for the linearity error of the position detection device 101B to increase as the absolute value of the offset amount [mm] in the Y-axis direction increases.

[0095] <2. Modifications> Although the present technology has been described above by way of the embodiments, the present technology is not limited to the above embodiments and various modifications are possible. For example, in the above embodiments, a full bridge circuit is formed using four resistance parts in the magnetic sensor, but in the present invention, for example, a half bridge circuit may be formed using two resistance parts. In addition, the shapes and dimensions of the multiple magnetoresistance effect elements may be the same as each other or may be different. In addition, the resistance part may include, for example, a magnetic detection element. The magnetic detection element may be an element having a function of detecting a magnetic field, and is not limited to a spin-valve type MR element, but also includes an anisotropic magnetoresistance effect element (AMR element) and a Hall element (for example, a planar Hall element or a vertical Hall element). In general, a planar Hall element tends to have a sensitivity axis perpendicular to the substrate, and a magnetoresistance effect element and a vertical Hall element tend to have a sensitivity axis parallel to the substrate, but in one embodiment of the present technology, it is preferable to use a magnetic detection element having a sensitivity axis parallel to the substrate or a plane perpendicular to the Z axis. In addition, the dimensions of each component and the layout of each component are examples and are not limited to these.

[0096] Furthermore, the position detection device according to an embodiment of the present technology is not limited to a device for detecting the position of a lens, but may be a device for detecting the spatial position of an object other than a lens.

[0097] In addition, in the above first embodiment, the first magnet 10 includes two region portions (the first region portion 11 and the second region portion 12), but the first multi-pole magnet of one embodiment of the present technology is not limited to this and may include, for example, three or more region portions.

[0098] Note that orthogonal is not only a concept of being geometrically strictly 90°, but also a concept including an error of about a manufacturing error from 90°, for example about ±5°.

[0099] According to a position detection device, a lens module, an imaging device, and a distance measuring device as an embodiment of the present technology, high position detection accuracy can be achieved.

[0100] The correspondence between the reference numerals and the components in this embodiment is summarized below. [Explanation of symbols]

[0101] 100...imaging device, 200...image sensor, 300...lens module, 401...range measuring device, 1, 1A, 1B...position detection device, 3...drive device, 4...control unit, 5...lens, 6...housing, 7...substrate, 7a...upper surface, 7K...opening, 11...first region, 12...second region, 13...neutral zone, 31...first magnet, 32...second magnet, 14...first holding member, 15...second holding member, 16...wire, 17...spring, 20, 30...magnetic sensor, 41-46...coil, 150...MR element, 162...lower electrode, 163...upper electrode, 151...magnetization free layer, 152...nonmagnetic layer, 153...magnetization fixed layer, 154...antiferromagnetic layer, MF1...first magnetic field, MF2...second magnetic field, MF...composite magnetic field.

Claims

1. A magnetic sensor; a first magnetic field generating unit that is disposed so as to face the magnetic sensor at a distance in a first axial direction, has a first multi-pole magnet including a plurality of N poles and a plurality of S poles adjacent to each other in the first axial direction, and generates a first magnetic field that reaches the magnetic sensor; Equipped with the magnetic sensor and the first magnetic field generating unit are provided so as to be relatively movable in a second axis direction perpendicular to the first axis direction, a center position of the magnetic sensor in a third axis direction perpendicular to both the first axis direction and the second axis direction is different from a center position of the first multi-pole magnet in the third axis direction; at least a portion of the magnetic sensor and at least a portion of the first multi-pole magnet overlap each other so as to face each other in the first axial direction; a boundary between the N pole and the S pole adjacent to each other in the first axial direction extends along a first plane perpendicular to the first axial direction, The magnetic sensor extends along the first plane and generates a detection signal corresponding to a direction of a target magnetic field including a second axial magnetic field component along the second axis and a third axial magnetic field component along the third axis. Position detection device.

2. The magnetic sensor has a first opposing surface facing the first multi-pole magnet, the first multi-pole magnet has a second facing surface facing the magnetic sensor; The first opposing surface and the second opposing surface are both parallel to the first plane.

2. The position detection device according to claim 1.

3. The dimension of the first multi-pole magnet in the first axial direction is smaller than the dimension of the first multi-pole magnet in the third axial direction.

2. The position detection device according to claim 1.

4. The second axis direction is a direction of rotation about a central axis of rotation along the third axis direction. The position detection device according to any one of claims 1 to 3.

5. The second axis direction is a direction of rotation about a central axis of rotation along the first axis direction. The position detection device according to any one of claims 1 to 3.

6. The first multi-pole magnet has a curved shape in a first plane perpendicular to the third axis direction.

5. The position detection device according to claim 4.

7. The first multi-pole magnet has an overall shape of a substantially rectangular parallelepiped. The position detection device according to any one of claims 1 to 3.

8. The first multi-pole magnet has a curved shape in a second plane perpendicular to the first axial direction.

6. The position detection device according to claim 5.

9. the first multi-pole magnet includes a first N pole and a second N pole as the plurality of N poles and includes a first S pole and a second S pole as the plurality of S poles; The first N pole and the first S pole are disposed adjacent to each other in the first axial direction, The second N pole and the second S pole are disposed adjacent to each other in the first axial direction, The first N pole and the second S pole are disposed adjacent to each other in the second axial direction, The second N pole and the first S pole are disposed adjacent to each other in the second axial direction.

2. The position detection device according to claim 1.

10. The first multi-pole magnet comprises: a first region portion magnetized in a first direction along the first axial direction; a second region portion magnetized in a second direction opposite to the first direction along the first axial direction; Includes 2. The position detection device according to claim 1.

11. The first multi-pole magnet further includes a neutral zone between the first region and the second region. The position detection device according to claim 10.

12. The neutral zone extends along a third plane perpendicular to the second axial direction. The position detection device according to claim 11.

13. The first multi-pole magnet has a longitudinal direction along the second axial direction.

2. The position detection device according to claim 1.

14. The magnetic sensor and the first multi-pole magnet are provided so as to be relatively movable along the second axial direction while maintaining a mutually overlapping state in the first axial direction.

2. The position detection device according to claim 1.

15. Further comprising a second magnetic field generating unit that generates a second magnetic field, The first magnetic field generating unit is provided so as to be movable along the second axial direction relative to the magnetic sensor and the second magnetic field generating unit by the second magnetic field.

2. The position detection device according to claim 1.

16. A magnetic sensor; a first magnetic field generating unit that is disposed so as to face the magnetic sensor at a distance in a first axial direction, has a first multi-pole magnet including a plurality of N poles and a plurality of S poles adjacent to each other along the first axial direction, and generates a first magnetic field that reaches the magnetic sensor; a second magnetic field generating unit that generates a second magnetic field; Lens and Equipped with the magnetic sensor and the second magnetic field generating unit, the first magnetic field generating unit and the lens are provided so as to be relatively movable along a second axis direction perpendicular to the first axis direction, a center position of the magnetic sensor in a third axis direction perpendicular to both the first axis direction and the second axis direction is different from a center position of the first multi-pole magnet in the third axis direction; at least a portion of the magnetic sensor and at least a portion of the first multi-pole magnet overlap each other so as to face each other in the first axial direction; a boundary between the N pole and the S pole adjacent to each other in the first axial direction extends along a first plane perpendicular to the first axial direction, The magnetic sensor extends along the first plane and generates a detection signal corresponding to a direction of a target magnetic field including a second axial magnetic field component along the second axis and a third axial magnetic field component along the third axis. Lens module.

17. An imaging element; Lens module and Equipped with The lens module includes: A magnetic sensor; a first magnetic field generating unit that is disposed so as to face the magnetic sensor at a distance in a first axial direction, has a first multi-pole magnet including a plurality of N poles and a plurality of S poles adjacent to each other along the first axial direction, and generates a first magnetic field that reaches the magnetic sensor; a second magnetic field generating unit that generates a second magnetic field; Lens and Equipped with the magnetic sensor and the second magnetic field generating unit, the first magnetic field generating unit and the lens are provided so as to be relatively movable along a second axis direction perpendicular to the first axis direction, a center position of the magnetic sensor in a third axis direction perpendicular to both the first axis direction and the second axis direction is different from a center position of the first multi-pole magnet in the third axis direction; at least a portion of the magnetic sensor and at least a portion of the first multi-pole magnet overlap each other so as to face each other in the first axial direction; a boundary between the N pole and the S pole adjacent to each other in the first axial direction extends along a first plane perpendicular to the first axial direction, The magnetic sensor extends along the first plane and generates a detection signal corresponding to a direction of a target magnetic field including a second axial magnetic field component along the second axis and a third axial magnetic field component along the third axis. Imaging device.

18. A distance measuring device that measures the distance to an object by detecting irradiated light, An optical element configured to change the direction of travel of the light and to rotate; A magnetic sensor; a magnetic field generating unit that is disposed so as to face the magnetic sensor at a distance in a first axial direction, has a first multi-pole magnet including a plurality of N poles and a plurality of S poles adjacent to each other along the first axial direction, and generates a magnetic field that reaches the magnetic sensor; Equipped with the magnetic sensor and the magnetic field generating unit are provided so as to be relatively movable in a second axis direction perpendicular to the first axis direction, The magnetic field generating unit is configured to rotate in the second axis direction around a rotation axis in conjunction with the optical element, The magnetic sensor in a third axis direction perpendicular to both the first axis direction and the second axis direction a center position of the sensor is different from a center position of the first multi-pole magnet in the third axial direction, at least a portion of the magnetic sensor and at least a portion of the first multi-pole magnet overlap each other so as to face each other in the first axial direction; a boundary between the N pole and the S pole adjacent to each other in the first axial direction extends along a first plane perpendicular to the first axial direction, The magnetic sensor extends along the first plane and generates a detection signal corresponding to a direction of a target magnetic field including a second axial magnetic field component along the second axis and a third axial magnetic field component along the third axis. Ranging device.

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