Position detection device, camera module and rotary actuator

Abstract

The position detection device of the present invention comprises a magnetic field generator and a magnetic sensor. The magnetic field generator is configured such that the direction of the target magnetic field changes nonlinearly with respect to the change in the position of the lens. The magnetic sensor is configured such that the direction of the detection signal changes nonlinearly with respect to the change in the direction of the target magnetic field.

Description

Technical Field

[0001] The present invention relates to a position detection device using a magnetic sensor, a camera module using the position detection device, and a rotary actuator using the position detection device. Background Art

[0002] In recent years, position detection devices using magnetic sensors have been used in various applications. Hereinafter, position detection devices using magnetic sensors are referred to as magnetic position detection devices. Magnetic position detection devices are used, for example, in camera modules with autofocus mechanisms built into smartphones to detect the position of lenses.

[0003] The following technology is described in U.S. Patent Application Publication No. 2016 / 0231528A1: In an autofocus mechanism in which a lens is configured to be movable relative to a substrate, a position sensor is used to detect a composite vector generated by the interaction of a first magnetic field of a certain magnitude in a first direction and a second magnetic field in a second direction generated by a magnet that moves with the lens. The second direction is orthogonal to the first direction. In this technology, the magnitude of the second magnetic field changes according to the position of the lens, and as a result, the angle formed by the composite vector relative to the second direction (hereinafter referred to as the angle of the composite vector) also changes. According to this technology, the position of the lens can be detected by detecting the angle of the composite vector.

[0004] The specification of Chinese patent application publication No. 109725269A describes a position detection device, which uses a magnetoresistive effect element of a spin valve structure and has: a first magnetic field generating unit; a second magnetic field generating unit, whose position relative to the first magnetic field generating unit can be changed; a magnetic sensor, which generates a detection signal corresponding to the direction of the magnetic field of the detection object, and the magnetic field of the detection object is a composite magnetic field of the magnetic field generated by the first magnetic field generating unit and the magnetic field generated by the second magnetic field generating unit. In this position detection device, when the relative position of the second magnetic field generating unit relative to the first magnetic field generating unit changes, the direction and intensity of the magnetic field of the detection object also change. According to this position detection device, by measuring the detection signal, the relative position of the second magnetic field generating unit relative to the first magnetic field generating unit can be detected.

[0005] As described in the specifications of U.S. Patent Application Publication No. 2016 / 0231528A1 and China Patent Application Publication No. 109725269A, in a magnetic position detection device, when the position of the detection object of the position detection device (hereinafter referred to as the object) changes, the direction of the magnetic field of the detection object of the magnetic sensor (hereinafter referred to as the object magnetic field) also changes. In addition, when the direction of the object magnetic field changes, the detection signal also changes. Preferably, the detection signal changes linearly with respect to the change in the position of the object. In addition, the detection signal "linearly changes" means that in the characteristic diagram showing the relationship between the position of the object and the detection signal, the detection signal changes linearly or approximately linearly with respect to the change in the position of the object. In addition, the detection signal "nonlinearly changes" means that in the above-mentioned characteristic diagram, the detection signal changes in a curve relative to the change in the position of the object, etc., and does not change linearly or approximately linearly.

[0006] In order to make the detection signal change linearly with respect to the change of the position of the object, it is preferred that the direction of the object magnetic field changes linearly with respect to the change of the position of the object, and the detection signal changes linearly with respect to the change of the direction of the object magnetic field. Fig.10 It is disclosed that the angle formed by the direction of the target magnetic field with respect to the reference direction changes linearly with respect to the change in the relative position of the second magnetic field generating unit with respect to the first magnetic field generating unit.

[0007] However, in reality, due to mechanical limitations, the direction of the target magnetic field may have to change in a nonlinear manner relative to the position of the target object. Figure 8 B discloses that the angle of the synthetic vector changes linearly, that is, nonlinearly, with respect to the change in the position of the magnet moving together with the lens. In this case, the detection signal changes nonlinearly with respect to the change in the position of the object, and therefore processing is required to correct the detection signal. Summary of the invention

[0008] Problems to be solved by the invention

[0009] The object of the present invention is to provide a position detection device, a camera module using the position detection device, and a rotation actuator using the position detection device. The position detection device is a position detection device using a magnetic sensor, which can make the detection signal change linearly relative to the change of the position of the object even when the direction of the object magnetic field changes nonlinearly relative to the change of the position of the object.

[0010] Technical solutions to solve problems

[0011] The position detection device of the present invention is a position detection device for detecting the position of an object whose position can be changed. The position detection device of the present invention comprises: a magnetic field generator, which generates an object magnetic field and is configured so that when the position of the object changes, the direction of the object magnetic field at the detection position in the reference plane changes; and a magnetic sensor, which detects the object magnetic field and generates a detection signal corresponding to the direction of the object magnetic field.

[0012] The magnetic field generator is configured such that the direction of the target magnetic field changes nonlinearly with respect to the position of the target object. The magnetic sensor is configured such that the detection signal changes nonlinearly with respect to the direction of the target magnetic field.

[0013] In the position detection device of the present invention, it is also possible that the object angle formed by the direction of the object magnetic field relative to the reference direction in the reference plane changes within a first variable range corresponding to the movable range of the position of the object. In this case, it is also possible that the detection signal changes within a second variable range corresponding to the first variable range. In addition, in this case, it is also possible that the magnetic sensor includes at least one magnetoresistance effect element. It is also possible that each of the at least one magnetoresistance effect elements includes a magnetization fixed layer parallel to the reference plane and having a first magnetization with a fixed direction, and a free layer parallel to the reference plane and having a second magnetization whose direction can change according to the direction of the object magnetic field, and when the object is located at the center of the movable range, the angle formed by the direction of the second magnetization relative to the direction of the first magnetization is within a range of 0° to 70°, within a range of 110° to 250°, or within a range of 290° to less than 360°.

[0014] In addition, in the position detection device of the present invention, when the magnetic sensor includes at least one magnetoresistance effect element, each of the at least one magnetoresistance effect elements is constructed in such a manner that when the object is located at the center of the movable range, the angle formed by the direction of the second magnetization with respect to the direction of the first magnetization is within a range of not less than 10° and not more than 60°, within a range of not less than 120° and not more than 170°, within a range of not less than 190° and not more than 240°, or within a range of not less than 300° and not more than 350°.

[0015] In addition, in the position detection device of the present invention, it is also possible that, when the magnetic sensor includes at least one magnetoresistance effect element, the at least one magnetoresistance effect element is at least one first magnetoresistance effect element and at least one second magnetoresistance effect element. In addition, it is also possible that the magnetic sensor further includes a resistor having a specified resistance value, a power supply port to which a specified voltage is applied, a ground port connected to a ground line, and an output port. In this case, at least one first magnetoresistance effect element is arranged between the power supply port and the output port. At least one second magnetoresistance effect element is arranged between the output port and the ground port.

[0016] Alternatively, the resistor may be connected in series with at least one first magnetoresistance effect element in a manner of being arranged between the power supply port and the output port, or may be connected in series with at least one second magnetoresistance effect element in a manner of being arranged between the output port and the ground port. The direction of the first magnetization of each magnetization fixed layer of at least one first magnetoresistance effect element is the first direction. The direction of the first magnetization of each magnetization fixed layer of at least one second magnetoresistance effect element is the second direction opposite to the first direction. The detection signal depends on the potential of the output port.

[0017] In addition, in the position detection device of the present invention, it is also possible that, when the magnetic sensor includes at least one magnetoresistance effect element, the at least one magnetoresistance effect element is at least one first magnetoresistance effect element, at least one second magnetoresistance effect element, at least one third magnetoresistance effect element, and at least one fourth magnetoresistance effect element. In addition, it is also possible that the magnetic sensor further includes a first resistor and a second resistor each having a specified resistance value, a power supply port to which a specified voltage is applied, a ground port connected to a ground wire, a first output port, and a second output port. In this case, at least one first magnetoresistance effect element is arranged between the power supply port and the first output port. At least one second magnetoresistance effect element is arranged between the first output port and the ground port. At least one third magnetoresistance effect element is arranged between the power supply port and the second output port. At least one fourth magnetoresistance effect element is arranged between the second output port and the ground port.

[0018] It is also possible that, of the first resistor and the second resistor, the first resistor is connected in series with at least one first magnetoresistance effect element in a manner of being arranged between the power supply port and the first output port, and the second resistor is connected in series with at least one fourth magnetoresistance effect element in a manner of being arranged between the second output port and the ground port, or the first resistor is connected in series with at least one second magnetoresistance effect element in a manner of being arranged between the first output port and the ground port, and the second resistor is connected in series with at least one third magnetoresistance effect element in a manner of being arranged between the power supply port and the second output port. The direction of the first magnetization of each magnetization fixed layer of the at least one first magnetoresistance effect element and the direction of the first magnetization fixed layer of each magnetization fixed layer of the at least one fourth magnetoresistance effect element are the first direction. The direction of the first magnetization of each magnetization fixed layer of the at least one second magnetoresistance effect element and the direction of the first magnetization fixed layer of each magnetization fixed layer of the at least one third magnetoresistance effect element are the second direction opposite to the first direction. The detection signal depends on the potential difference between the first output port and the second output port.

[0019] In addition, in the position detection device of the present invention, the position of the object may change in the direction of a straight line. In this case, the magnetic field generator may include a first magnetic field generating unit that generates a first magnetic field and a second magnetic field generating unit that generates a second magnetic field. It is also possible that the relative position of the second magnetic field generating unit relative to the first magnetic field generating unit changes with the change of the position of the object. It is also possible that when the component of the first magnetic field parallel to the reference plane at the detection position is set as the first magnetic field component, and the component of the second magnetic field parallel to the reference plane at the detection position is set as the second magnetic field component, the first magnetic field generating unit and the second magnetic field generating unit are configured in such a way that when the relative position of the second magnetic field generating unit relative to the first magnetic field generating unit changes, the intensity of the first magnetic field component and the direction of the first magnetic field component and the direction of the second magnetic field component do not change, but the intensity of the second magnetic field component changes. It is also possible that the object magnetic field is a composite magnetic field of the first magnetic field component and the second magnetic field component.

[0020] Alternatively, when the magnetic field generator includes the first and second magnetic field generating units, the first magnetic field generating unit may include two magnets disposed at different positions. Alternatively, the first magnetic field may be a magnetic field synthesized from two magnetic fields generated by the two magnets. In addition, in this case, the position detection device of the present invention may further include: a first holding member that holds the first magnetic field generating unit; and a second holding member that is configured to be positionally changeable in one direction relative to the first holding member and holds the second magnetic field generating unit.

[0021] When the position detection device of the present invention includes first and second holding members, the object may be a lens. Alternatively, the second holding member is a member that holds the lens and is provided so as to be positionally changeable in the optical axis direction of the lens relative to the first holding member.

[0022] In the position detection device of the present invention, the object may be a rotating body whose position changes along a rotation direction around a central axis. In this case, the magnetic field generator may be connected to the rotating body.

[0023] The camera module of the present invention comprises: a lens whose position can be changed in the direction of a straight line; a position detection device for detecting the position of the lens; a holding component for holding the lens; and a driving device for moving the holding component. The position detection device includes: a magnetic field generator, which generates an object magnetic field and is configured in such a way that the direction of the object magnetic field at the detection position in the reference plane changes when the position of the lens changes; and a magnetic sensor, which detects the object magnetic field and generates a detection signal corresponding to the direction of the object magnetic field. The magnetic field generator is configured such that the direction of the object magnetic field changes nonlinearly with respect to the change in the position of the lens. The magnetic sensor is configured such that the detection signal changes nonlinearly with respect to the change in the direction of the object magnetic field.

[0024] The rotary actuator of the present invention comprises: a rotating body whose position can be changed along the rotation direction centered on the central axis; a position detection device for detecting the position of the rotating body; and a driving device for rotating the rotating body. The position detection device includes: a magnetic field generator, which generates an object magnetic field and is configured in such a way that the direction of the object magnetic field at the detection position in the reference plane changes when the position of the rotating body changes; and a magnetic sensor, which detects the object magnetic field and generates a detection signal corresponding to the direction of the object magnetic field. The magnetic field generator is configured so that the direction of the object magnetic field changes nonlinearly with respect to the change in the position of the rotating body. The magnetic sensor is configured so that the detection signal changes nonlinearly with respect to the change in the direction of the object magnetic field.

[0025] Effects of the Invention

[0026] In the position detection device, camera module and rotary actuator of the present invention, the magnetic field generator is configured such that the direction of the target magnetic field changes nonlinearly relative to the change in the position of the object, and the magnetic sensor is configured such that the detection signal changes nonlinearly relative to the change in the direction of the target magnetic field. Thus, according to the position detection device of the present invention, even when the direction of the target magnetic field changes nonlinearly relative to the change in the position of the object, the detection signal can be changed linearly relative to the change in the position of the object. Similarly, according to the camera module of the present invention, even when the direction of the target magnetic field changes nonlinearly relative to the change in the position of the lens, the detection signal can be changed linearly relative to the change in the position of the lens. Similarly, according to the rotary actuator of the present invention, even when the direction of the target magnetic field changes nonlinearly relative to the change in the position of the rotating body, the detection signal can be changed linearly relative to the change in the position of the rotating body.

[0027] Other objects, features and advantages of the present invention will become apparent from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a perspective view showing a camera module according to a first embodiment of the present invention.

[0029] Figure 2 It is an explanatory diagram schematically showing the interior of the camera module according to the first embodiment of the present invention.

[0030] Figure 3 It is a perspective view showing a position detection device and a driving device according to a first embodiment of the present invention.

[0031] Figure 4 Yes means Figure 1 A three-dimensional diagram of multiple coils of a driving device in FIG.

[0032] Figure 5 Yes means Figure 1 A side view of the main parts of the drive device.

[0033] Figure 6 It is a perspective view showing the main part of the position detection device according to the first embodiment of the present invention.

[0034] Figure 7 This is a circuit diagram showing the structure of a magnetic sensor according to a first embodiment of the present invention.

[0035] Figure 8 Yes means Figure 7 A perspective view of a portion of a resistor portion.

[0036] Fig. 9 It is a characteristic diagram showing the relationship between the relative position and the first and second magnetic field components according to the first embodiment of the present invention.

[0037] Fig.10 It is a characteristic diagram showing the relationship between the relative position and the target angle according to the first embodiment of the present invention.

[0038] Fig.11 It is a characteristic diagram showing the relationship between the relative angle and the detection signal according to the first embodiment of the present invention.

[0039] Fig.12 Schematic diagram showing the relationship between the target angle and the detection signal according to the first embodiment of the present invention.

[0040] Fig.13 It is an explanatory diagram showing the directions of the first and second magnetizations in the position detection device according to the first comparative example.

[0041] Fig.14 It is an explanatory diagram showing the directions of the first and second magnetizations in the position detection device according to the first embodiment.

[0042] Fig.15 It is a characteristic diagram showing the relationship between the relative positions and relative angles of the position detection device of the first comparative example and the position detection device of the first embodiment.

[0043] Fig.16 It is a characteristic diagram showing the relationship between the relative position, the detection signal, and the third linear parameter in the position detection device of the first comparative example.

[0044] Fig.17 It is a characteristic diagram showing the relationship between the relative position, the detection signal, and the third linear parameter in the position detection device of the first embodiment.

[0045] Fig.18 : is a circuit diagram showing the structure of a magnetic sensor in a position detection device according to a second comparative example.

[0046] Fig.19 It is a characteristic diagram showing the relationship between the relative position and the detection signal in the position detection device of the second comparative example.

[0047] Fig. 20 It is a plan view showing a rotary actuator according to a second embodiment of the present invention.

[0048] Fig.21 It is a characteristic diagram showing the relationship between the rotation position and the target angle according to the second embodiment of the present invention.

[0049] Fig. 22It is a characteristic diagram showing the relationship between the relative position and the detection signal in the position detection device of the third comparative example.

[0050] Fig.23 It is a characteristic diagram showing the relationship between the relative position and the detection signal in the position detection device according to the second embodiment.

[0051] Fig.24 1 is a characteristic diagram showing the relationship between the rotational position and the third linear parameter of the position detection device of the third comparative example and the position detection device of the second embodiment. DETAILED DESCRIPTION

[0052] [First embodiment]

[0053] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Figure 1 and Figure 2 The structure of the camera module according to the first embodiment of the present invention will be described. Figure 1 2 is a perspective view showing the camera module 100 . Figure 2 1 is an explanatory diagram schematically showing the interior of the camera module 100. Figure 2 In order to make it easier to understand, Figure 1 The camera module 100 is described with different sizes and configurations of the corresponding parts. The camera module 100 of this embodiment constitutes a part of a camera for a smartphone having an optical hand shake correction mechanism and an autofocus mechanism, and is used in combination with an image sensor 110 using a CMOS or the like.

[0054] The camera module 100 according to the present embodiment comprises a position detection device 1, a drive device 3, a lens 5, a frame 6, and a substrate 7 according to the present embodiment. The position detection device 1 according to the present embodiment is a magnetic position detection device for detecting the position of the lens 5 when performing automatic focusing. The drive device 3 is a device for moving the lens 5. The frame 6 is a component for protecting the position detection device 1 and the drive device 3. The substrate 7 has an upper surface 7a. In addition, Figure 1 The substrate 7 is omitted. Figure 2 Frame 6 is omitted.

[0055] Here, if Figure 1 and Figure 2 As shown in FIG. 1 , a U direction, a V direction, and a Z direction are defined. The U direction, the V direction, and the Z direction are orthogonal to each other. In this embodiment, a direction ( Figure 2The direction toward the upper side in the reference position is referred to as the Z direction. The U direction and the V direction are both directions parallel to the upper surface 7a of the substrate 7. In addition, the direction opposite to the U direction is referred to as the -U direction, the direction opposite to the V direction is referred to as the -V direction, and the direction opposite to the Z direction is referred to as the -Z direction. In addition, hereinafter, the position at the front end in the Z direction relative to the reference position is referred to as "above", and the position on the opposite side of the "above" relative to the reference position is referred to as "below".

[0056] The lens 5 is disposed above the upper surface 7a of the substrate 7 in a posture in which the optical axis direction thereof coincides with the direction parallel to the Z direction. In addition, the substrate 7 has an opening (not shown) through which the light passing through the lens 5 passes. Figure 2 As shown, the camera module 100 is aligned with respect to the image sensor 110 so that light having passed through the lens 5 and an opening (not shown) is incident on the image sensor 110 .

[0057] Next, refer to Figures 2 to 5 The position detection device 1 and the drive device 3 according to the present embodiment will be described in detail. Figure 3 It is a perspective view showing the position detection device 1 and the driving device 3 . Figure 4 It is a perspective view showing a plurality of coils of the driving device 3 . Figure 5 It is a side view showing the main part of the driving device 3.

[0058] The position detection device 1 includes a first holding member 14, a second holding member 15, a plurality of first conductive wires 16, and a plurality of second conductive wires 17. The second holding member 15 is a member for holding the lens 5. Although not shown, the second holding member 15 has a cylindrical shape, for example, configured so that the lens 5 can be mounted therein.

[0059] The second holding member 15 is provided so as to be positionally changeable in one direction, specifically, in the direction of the optical axis of the lens 5, i.e., in a direction parallel to the Z direction, relative to the first holding member 14. In the present embodiment, the first holding member 14 has a box-like shape configured so as to accommodate the lens 5 and the second holding member 15 therein. A plurality of second conductive wires 17 connect the first holding member 14 and the second holding member 15, and support the second holding member 15 so as to be movable relative to the first holding member 14 in a direction parallel to the Z direction.

[0060] The first holding member 14 is provided above the upper surface 7a of the substrate 7, and is capable of changing its position relative to the substrate 7 in a direction parallel to the U direction and a direction parallel to the V direction. A plurality of first wires 16 connect the substrate 7 and the first holding member 14, and support the first holding member 14 in a manner that the first holding member 14 can move relative to the substrate 7 in a direction parallel to the U direction and a direction parallel to the V direction. When the relative position of the first holding member 14 relative to the substrate 7 changes, the relative position of the second holding member 15 relative to the substrate 7 also changes.

[0061] The drive device 3 includes magnets 31A, 31B, 32A, 32B, 33A, 33B, 34A, 34B and coils 41, 42, 43, 44, 45, 46. The magnet 31A is arranged at one end of the lens 5 in the -V direction. The magnet 32A is arranged at one end of the lens 5 in the V direction. The magnet 33A is arranged at one end of the lens 5 in the -U direction. The magnet 34A is arranged at one end of the lens 5 in the U direction. The magnets 31B, 32B, 33B, 34B are arranged above the magnets 31A, 32A, 33A, 34A, respectively. In addition, the magnets 31A, 31B, 32A, 32B, 33A, 33B, 34A, 34B are fixed to the first holding member 14.

[0062] like Figure 3 As shown, magnets 31A, 31B, 32A, and 32B each have a rectangular parallelepiped shape that is long in the U direction. Magnets 33A, 33B, 34A, and 34B each have a rectangular parallelepiped shape that is long in the V direction. The magnetization direction of magnets 31A and 32B is the V direction. The magnetization direction of magnets 31B and 32A is the -V direction. The magnetization direction of magnets 33A and 34B is the U direction. The magnetization direction of magnets 33B and 34A is the -U direction. Figure 5 , arrows drawn within the magnets 31A and 31B indicate the directions of magnetization of the magnets 31A and 31B.

[0063] The coil 41 is arranged between the magnet 31A and the substrate 7. The coil 42 is arranged between the magnet 32A and the substrate 7. The coil 43 is arranged between the magnet 33A and the substrate 7. The coil 44 is arranged between the magnet 34A and the substrate 7. The coil 45 is arranged between the magnets 31A and 31B and the lens 5. The coil 46 is arranged between the magnets 32A and 32B and the lens 5. In addition, the coils 41, 42, 43, and 44 are fixed to the substrate 7. The coils 45 and 46 are fixed to the second holding member 15.

[0064] The magnetic field generated by the magnet 31A is mainly applied to the coil 41. The magnetic field generated by the magnet 32A is mainly applied to the coil 42. The magnetic field generated by the magnet 33A is mainly applied to the coil 43. The magnetic field generated by the magnet 34A is mainly applied to the coil 44.

[0065] In addition, if Figure 2 , Figure 4 and Figure 5 As shown, the coil 45 includes a first conductor portion 45A extending in the U direction along the magnet 31A, a second conductor portion 45B extending in the U direction along the magnet 31B, and two third conductor portions connecting the first and second conductor portions 45A and 45B. Figure 2 and Figure 4 As shown, the coil 46 includes a first conductor portion 46A extending in the U direction along the magnet 32A, a second conductor portion 46B extending in the U direction along the magnet 32B, and two third conductor portions connecting the first and second conductor portions 46A and 46B.

[0066] The V-direction component of the magnetic field generated by the magnet 31A is mainly applied to the first conductor portion 45A of the coil 45. The -V-direction component of the magnetic field generated by the magnet 31B is mainly applied to the second conductor portion 45B of the coil 45. The -V-direction component of the magnetic field generated by the magnet 32A is mainly applied to the first conductor portion 46A of the coil 46. The V-direction component of the magnetic field generated by the magnet 32B is mainly applied to the second conductor portion 46B of the coil 46.

[0067] The position detection device 1 also includes a magnetic field generator 10 and a magnetic sensor 20. The magnetic field generator 10 generates a magnetic field (detection target magnetic field) to be detected by the magnetic sensor 20, that is, a target magnetic field MF. In the present embodiment, the magnetic field generator 10 includes a first magnetic field generating unit 11 that generates a first magnetic field and a second magnetic field generating unit 12 that generates a second magnetic field. The first magnetic field generating unit 11 has two magnets arranged at different positions. In the present embodiment, in particular, the first magnetic field generating unit 11 has magnets 31A and 34A as the above-mentioned two magnets. The first magnetic field is a magnetic field synthesized by the magnetic fields respectively generated by the magnets 31A and 34A. As described above, the magnets 31A and 34A are fixed to the first holding member 14. Therefore, the first magnetic field generating unit 11 is held by the first holding member 14.

[0068] like Figure 3 As shown, the magnet 31A has an end surface 31A1 located at one end of the magnet 31A in the U direction. The magnet 34A has an end surface 34A1 located at one end of the magnet 34A in the -V direction.

[0069] The second magnetic field generating unit 12 is provided in a manner that its relative position relative to the first magnetic field generating unit 11 can be changed. In the present embodiment, the second magnetic field generating unit 12 has a magnet 13. The second magnetic field is a magnetic field generated by the magnet 13. The magnet 13 has a rectangular parallelepiped shape. In addition, the magnet 13 is fixed to the second holding member 15 in a space near the end face 31A1 of the magnet 31A and the end face 34A1 of the magnet 34A. Thus, the second magnetic field generating unit 12 is held by the second holding member 15. When the relative position of the second holding member 15 relative to the first holding member 14 changes in a direction parallel to the Z direction, the relative position of the second magnetic field generating unit 12 relative to the first magnetic field generating unit 11 also changes in a direction parallel to the Z direction.

[0070] The magnetic sensor 20 includes at least one magnetoresistance effect element. Hereinafter, the magnetoresistance effect element is referred to as an MR element. The magnetic sensor 20 detects the object magnetic field MF at the detection position in the reference plane and generates a detection signal corresponding to the direction of the object magnetic field MF. The magnetic sensor 20 is fixed to the substrate 7 near the end face 31A1 of the magnet 31A and the end face 34A1 of the magnet 34A. The distance from the magnet 31A to the magnetic sensor 20 and the distance from the magnet 34A to the magnetic sensor 20 are equal to each other. The magnet 13 is arranged above the magnetic sensor 20.

[0071] The detection position is the position where the magnetic sensor 20 detects the first magnetic field and the second magnetic field. In the present embodiment, the reference plane is a plane that includes the detection position and is perpendicular to the Z direction. When the relative position of the second magnetic field generating unit 12 relative to the first magnetic field generating unit 11 changes, the distance between the detection position and the second magnetic field generating unit 12 also changes.

[0072] Here, the component of the first magnetic field parallel to the reference plane at the detection position is assumed to be the first magnetic field component MF1, and the component of the second magnetic field parallel to the reference plane at the detection position is assumed to be the second magnetic field component MF2. The object magnetic field MF is a composite magnetic field of the first magnetic field component MF1 and the second magnetic field component MF2. In addition, the first and second magnetic field components MF1, MF2 and the object magnetic field MF are described later. Figure 6 Shown in.

[0073] Hereinafter, the positional relationship among the first magnetic field generating unit 11 , the second magnetic field generating unit 12 , and the magnetic sensor 20 , and the structure of the magnetic sensor 20 will be described in further detail.

[0074] The driving device 3 further includes a magnetic sensor 30 fixed to the substrate 7 on the inner side of one of the coils 41 and 42 and a magnetic sensor 30 fixed to the substrate 7 on the inner side of one of the coils 43 and 44. Here, the two magnetic sensors 30 are respectively arranged on the inner side of the coil 41 and the inner side of the coil 44. As described later, the two magnetic sensors 30 are used when changing the position of the lens 5 in order to reduce the influence of hand shaking.

[0075] The magnetic sensor 30 disposed inside the coil 41 detects the magnetic field generated by the magnet 31A and generates a signal corresponding to the position of the magnet 31A. The magnetic sensor 30 disposed inside the coil 44 detects the magnetic field generated by the magnet 34A and generates a signal corresponding to the position of the magnet 34A. The magnetic sensor 30 is composed of an element for detecting a magnetic field, such as a Hall element.

[0076] Next, refer to Figure 3 and Figure 6 , the positional relationship among the first magnetic field generating unit 11, the second magnetic field generating unit 12 and the magnetic sensor 20 will be described in detail. Figure 6 1 is a perspective view showing the main parts of the position detection device 1. Figure 6 As shown in FIG. 1 , the X direction and the Y direction are defined. The X direction and the Y direction are both relative to the upper surface 7a of the substrate 7 (refer to Figure 2 ). The X direction is a direction rotated 45° from the U direction toward the V direction. The Y direction is a direction rotated 45° from the V direction toward the -U direction. In addition, the direction opposite to the X direction is referred to as the -X direction, and the direction opposite to the Y direction is referred to as the -Y direction.

[0077] Figure 6 , the arrow with symbol MF1 represents the first magnetic field component MF1. In the present embodiment, the first magnetic field generating unit 11 and the magnetic sensor 20 are arranged in such a way that the direction of the first magnetic field component MF1 becomes the -Y direction. The direction of the first magnetic field component MF1 can be adjusted, for example, according to the positional relationship of the magnets 31A and 34A relative to the magnetic sensor 20 and the posture of the magnets 31A and 34A. The magnets 31A and 34A are preferably arranged symmetrically with respect to the YZ plane including the detection position.

[0078] Figure 6, the arrow with the symbol MF2 represents the second magnetic field component MF2. In addition, the arrow drawn in the magnet 13 represents the direction of magnetization of the magnet 13. The direction of the second magnetic field component MF2 is different from the direction of the first magnetic field component MF1. The direction of the object magnetic field MF is also different from any of the directions of the first magnetic field component MF1 and the second magnetic field component MF2, and is a direction between them. The variable range of the direction of the object magnetic field MF is less than 180°. In the present embodiment, in particular, the direction of the second magnetic field component MF2 is the -X direction orthogonal to the direction of the first magnetic field component MF1. The variable range of the direction of the object magnetic field MF in this case is less than 90°.

[0079] Next, refer to Figure 7 , an example of the structure of the magnetic sensor 20 is described. Figure 7 : is a circuit diagram showing the structure of the magnetic sensor 20. In the present embodiment, the magnetic sensor 20 is configured to generate a detection signal corresponding to the angle formed by the direction of the target magnetic field MF with respect to the reference direction as a detection signal corresponding to the direction of the target magnetic field MF. In the present embodiment, the reference direction is the X direction.

[0080] like Figure 7 As shown, the magnetic sensor 20 includes a power port V to which a specified voltage is applied, a ground port G connected to a ground line, a first output port E1, a second output port E2, a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4. The first resistor R1 is arranged between the power port V and the first output port E1. The second resistor R2 is arranged between the first output port E1 and the ground port G. The third resistor R3 is arranged between the power port V and the second output port E2. The fourth resistor R4 is arranged between the second output port E2 and the ground port G.

[0081] The first resistor section R1 includes at least one first MR element. The second resistor section R2 includes at least one second MR element. The third resistor section R3 includes at least one third MR element. The fourth resistor section R4 includes at least one fourth MR element.

[0082] In this embodiment, in particular, the first resistor section R1 includes multiple first MR elements connected in series, the second resistor section R2 includes multiple second MR elements connected in series, the third resistor section R3 includes multiple third MR elements connected in series, and the fourth resistor section R4 includes multiple fourth MR elements connected in series.

[0083] The magnetic sensor 20 further includes a first resistor Ro1 and a second resistor Ro2 each having a predetermined resistance value. The first resistor Ro1 is connected in series with at least one first MR element in such a manner that the first resistor Ro1 is disposed between the power supply port V and the first output port E1. The second resistor Ro2 is connected in series with at least one fourth MR element in such a manner that the second resistor Ro2 is disposed between the second output port E2 and the ground port G. Figure 7 In the example shown, the first resistor Ro1 is provided between the first resistor section R1 and the first output port E1. In addition, the second resistor Ro2 is provided between the fourth resistor section R4 and the ground port G.

[0084] Each of the multiple MR elements included in the magnetic sensor 20 is a spin valve type MR element. The spin valve type MR element has a magnetization fixed layer that is parallel to a reference plane and has a first magnetization whose direction is fixed, a free layer that is parallel to the reference plane and has a second magnetization whose direction can change according to the direction of the target magnetic field MF, and a gap layer arranged between the magnetization fixed layer and the free layer. The spin valve type MR element can be a TMR (tunnel magnetoresistance effect) element or a GMR (giant magnetoresistance effect) element. In a TMR element, the gap layer is a tunnel barrier layer. In a GMR element, the gap layer is a non-magnetic conductive layer. In a spin valve type MR element, the resistance value changes according to the angle formed by the direction of the second magnetization of the free layer relative to the direction of the first magnetization of the magnetization fixed layer. When the angle is 0°, the resistance value becomes the minimum value, and when the angle is 180°, the resistance value becomes the maximum value. Figure 7 In FIG. 1 , a solid arrow indicates the direction of magnetization of a fixed magnetization layer in the MR element, and a hollow arrow indicates the direction of magnetization of a free layer in the MR element.

[0085] The first magnetization direction of the magnetization fixed layers in the plurality of MR elements included in the first and fourth resistor sections R1 and R4 is a first direction. The first magnetization direction of the magnetization fixed layers in the plurality of MR elements included in the second and third resistor sections R2 and R3 is a second direction opposite to the first direction.

[0086] From the viewpoint of the manufacturing accuracy of the MR element, etc., the directions of the first magnetization of the fixed magnetization layers in the plurality of MR elements in the first to fourth resistor portions R1 to R4 may be slightly deviated from the above directions.

[0087] 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 change according to the cosine of the angle formed by the direction of the target magnetic field MF relative to the first direction. The magnetic sensor 20 outputs a signal corresponding to the potential difference between the output ports E1 and E2 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. In addition, since the detection signal changes according to the direction of the target magnetic field MF, it is a signal corresponding to the direction of the target magnetic field MF.

[0088] The magnetic sensor 20 may further include a differential detector (not shown). The differential detector (not shown) outputs a signal corresponding to the potential difference between the output ports E1 and E2 as a detection signal.

[0089] Here, refer to Figure 8 An example of the structure of the resistors R1 , R2 , R3 , and R4 will be described. Figure 8 1 is a perspective view showing a portion of one of the resistors R1, R2, R3, and R4. In this example, one resistor has a plurality of lower electrodes 62, a plurality of MR elements 50, and a plurality of upper electrodes 63. The plurality of lower electrodes 62 are arranged on a substrate (not shown). Each lower electrode 62 has an elongated shape. A gap is formed between two adjacent lower electrodes 62 in the long side direction of the lower electrode 62. Figure 8 As shown, MR elements 50 are respectively arranged on the upper surface of the lower electrode 62 near both ends in the long side direction. The MR element 50 includes a free layer 51, a gap layer 52, a magnetization fixed layer 53 and an antiferromagnetic layer 54 stacked in sequence from the lower electrode 62 side. The free layer 51 is electrically connected to the lower electrode 62. The antiferromagnetic layer 54 is made of an antiferromagnetic material so that exchange coupling occurs with the magnetization fixed layer 53 to fix the magnetization direction of the magnetization fixed layer 53. Multiple upper electrodes 63 are arranged on multiple MR elements 50. Each upper electrode 63 has an elongated shape and is arranged on two lower electrodes 62 adjacent to each other in the long side direction of the lower electrode 62 and electrically connects the antiferromagnetic layers 54 of the two adjacent MR elements 50. Through this structure, Figure 8 The resistor section shown has a plurality of MR elements 50 connected in series via a plurality of lower electrodes 62 and a plurality of upper electrodes 63 .

[0090] In addition, the configuration of the layers 51 to 54 in the MR element 50 may be different from Figure 8 The configuration shown is reversed up and down. In addition, the MR element 50 may be a structure that does not include the antiferromagnetic layer 54. This structure may be, for example, a structure that includes a magnetization pinned layer having an artificial antiferromagnetic structure, including two ferromagnetic layers and a nonmagnetic metal layer disposed between the two ferromagnetic layers, as a substitute for the antiferromagnetic layer 54 and the magnetization pinned layer 53.

[0091] Next, refer to Figure 2 to Figure 5 The operation of the drive device 3 is described. First, the optical hand-shake correction mechanism and the autofocus mechanism are briefly described. The drive device 3 constitutes a part of the optical hand-shake correction mechanism and the autofocus mechanism. The drive device 3, the optical hand-shake correction mechanism, and the autofocus mechanism are controlled by a control unit (not shown) outside the camera module 100.

[0092] The optical hand-shake correction mechanism is configured to detect hand-shake by, for example, a gyro sensor or the like outside the camera module 100. When the optical hand-shake correction mechanism detects hand-shake, the control unit (not shown) controls the drive device 3 in such a way that the relative position of the lens 5 relative to the substrate 7 changes according to the hand-shake mode. Thus, the absolute position of the lens 5 can be stabilized, thereby reducing the influence of hand-shake. In addition, the relative position of the lens 5 relative to the substrate 7 changes in a direction parallel to the U direction or a direction parallel to the V direction according to the hand-shake mode.

[0093] The autofocus mechanism is configured to detect a state in which the subject is in focus by, for example, the image sensor 110 or an autofocus sensor. The control unit (not shown) changes the relative position of the lens 5 with respect to the substrate 7 in a direction parallel to the Z direction through the drive device 3 so that the subject is in focus. Thus, the subject can be automatically focused.

[0094] Next, the operation of the drive device 3 related to the optical hand shake correction mechanism will be described. When a current flows through the coils 41 and 42 by a control unit (not shown), the first holding member 14 to which the magnets 31A and 32A are fixed moves in a direction parallel to the V direction due to the interaction between the magnetic field generated by the magnets 31A and 32A and the magnetic field generated by the coils 41 and 42. As a result, the lens 5 also moves in a direction parallel to the V direction. In addition, when a current flows through the coils 43 and 44 by a control unit (not shown), the first holding member 14 to which the magnets 33A and 34A are fixed moves in a direction parallel to the U direction due to the interaction between the magnetic field generated by the magnets 33A and 34A and the magnetic field generated by the coils 43 and 44. As a result, the lens 5 also moves in a direction parallel to the U direction. The control unit (not shown) detects the position of the lens 5 by measuring the signal corresponding to the position of the magnets 31A and 34A generated by the two magnetic sensors 30.

[0095] Next, the operation of the drive 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 in the Z direction, the control unit (not shown) causes the current to flow through the coil 45 so that the current flows through the first conductor portion 45A in the U direction and the current flows through the second conductor portion 45B in the -U direction, and causes the current to flow through the coil 46 so that the current flows through the first conductor portion 46A in the -U direction and the current flows through the second conductor portion 46B in the U direction. The Lorentz force in the Z direction acts on the first and second conductor portions 45A, 45B of the coil 45 and the first and second conductor portions 46A, 46B of the coil 46 by these currents and the magnetic field generated by the magnets 31A, 31B, 32A, 32B. As a result, the second holding member 15 to which the coils 45 and 46 are fixed moves in the Z direction. As a result, the lens 5 also moves in the Z direction.

[0096] When the relative position of the lens 5 with respect to the substrate 7 is moved in the −Z direction, a control unit (not shown) passes a current through the coils 45 and 46 in a direction opposite to that in the case of moving in the Z direction.

[0097] Next, the function and effect of the position detection device 1 of this embodiment are described. The position detection device 1 is used to detect the position of an object whose position can be changed. In this embodiment, the object is a lens 5 whose position changes in a straight line direction. The position detection device 1 involved in this embodiment is used to detect the position of the lens 5.

[0098] The magnetic field generator 10 is configured in such a way that when the position of the object, i.e., the lens 5, changes, the direction of the object magnetic field MF at the detection position in the reference plane also changes. In the present embodiment, the magnetic field generator 10 includes a first magnetic field generating unit 11 and a second magnetic field generating unit 12. When the relative position of the lens 5 relative to the substrate 7 changes, the relative position of the second holding member 15 relative to the substrate 7 and the first holding member 14 also changes. As described above, the first holding member 14 holds the first magnetic field generating unit 11, and the second holding member 15 holds the second magnetic field generating unit 12. Therefore, as described above, when the relative position of the lens 5 changes, the relative position of the second magnetic field generating unit 12 relative to the first magnetic field generating unit 11 also changes. Hereinafter, the relative position of the second magnetic field generating unit 12 relative to the first magnetic field generating unit 11 is referred to as a relative position, and is represented by a symbol PR. In the present embodiment, the direction of the change in the relative position is the optical axis direction of the lens 5, i.e., the direction parallel to the Z direction.

[0099] When the relative position changes, the relative position of the first magnetic field generating unit 11 relative to the substrate 7 does not change, but the relative position of the second magnetic field generating unit 12 relative to the substrate 7 changes. Therefore, when the relative position changes, the intensity and direction of the first magnetic field component MF1 and the direction of the second magnetic field component MF2 do not change, but the intensity of the second magnetic field component MF2 changes. When the intensity of the second magnetic field component MF2 changes, the direction and intensity of the target magnetic field MF also change, and along with this, the value of the detection signal generated by the magnetic sensor 20 also changes. The value of the detection signal changes depending on the relative position. The control unit not shown detects the relative position by measuring the detection signal. The direction and magnitude of the change in the relative position of the lens 5 relative to the substrate 7 are the same as the direction and magnitude of the change in the relative position. Therefore, it can also be said that the relative position represents the position of the lens 5, specifically the relative position of the lens 5 relative to the substrate 7.

[0100] In this embodiment, the distance between the detection position when the second magnetic field generating unit 12 is closest to the detection position and the second magnetic field generating unit 12 is set as the shortest distance, and the relative position is represented by the value obtained by subtracting the shortest distance from the distance between the second magnetic field generating unit 12 at any position and the detection position. In addition, the angle formed by the direction of the object magnetic field MF with respect to the reference direction, that is, the X direction, is called the object angle, which is represented by the symbol θ. Figure 6 The object angle θ is shown in Figure 6 In FIG. 1 , the arrow with the symbol DR indicates the reference direction. The target angle θ indicates the direction of the target magnetic field MF. In the present embodiment, the magnetic sensor 20 generates a detection signal corresponding to the target angle θ.

[0101] Next, the relationship between the relative position and the object angle θ will be described. Fig. 9 is a characteristic diagram showing the relationship between the relative position and the first and second magnetic field components MF1 and MF2. Fig. 9 In FIG. 1 , the horizontal axis represents the relative position, and the vertical axis represents the magnitude of the magnetic flux density corresponding to the strength of the first and second magnetic field components MF1 and MF2. Fig. 9 In FIG. 7 , symbol 71 represents the magnetic flux density corresponding to the intensity of the first magnetic field component MF1, and symbol 72 represents the magnetic flux density corresponding to the intensity of the second magnetic field component MF2. Fig. 9 As shown, when the relative position changes, the magnetic flux density 71 corresponding to the intensity of the first magnetic field component MF1 does not change, but the magnetic flux density 72 corresponding to the intensity of the second magnetic field component MF2 changes.

[0102] Fig.10 is a characteristic diagram showing the relationship between the relative position and the object angle θ. Fig.10 In , the horizontal axis represents the relative position and the vertical axis represents the object angle θ. Fig.10In FIG. 7 , reference numeral 73 denotes a curve showing the relationship between the relative position and the object angle θ, and reference numeral 74 denotes a line segment connecting both ends of the curve shown by reference numeral 73 .

[0103] Here, we focus on how the change in the object angle θ corresponds to the change in the relative position. Fig.10 In a characteristic diagram showing the relationship between two parameters, a method in which the other parameter changes linearly or approximately linearly with respect to a change in one parameter is called "linear change". In addition, in a characteristic diagram showing the relationship between two parameters, a method in which the other parameter changes not linearly or approximately linearly with respect to a change in one parameter, such as changing in a curve, is called "nonlinear change".

[0104] exist Fig.10 In , the object angle θ changes with respect to the relative position in a curve. Fig.10 In the embodiment, the target angle θ changes nonlinearly with respect to the change in the relative position. The target angle θ changes within a first variable range corresponding to the movable range of the relative position.

[0105] In the present embodiment, the magnetic field generator 10 is configured such that the direction of the target magnetic field MF changes nonlinearly with respect to the change in the relative position. In other words, the magnetic field generator 10 is configured such that the direction of the target angle θ changes nonlinearly with respect to the change in the relative position. Whether the target angle θ changes linearly or nonlinearly depends on, for example, the strength of the first and second magnetic field components MF1 and MF2 within the movable range of the relative position. The strength of the first and second magnetic field components MF1 and MF2 can be adjusted according to the position or characteristics of the magnets 13, 31A, and 34A.

[0106] The magnetic field generator 10 can be configured to, for example, change the object angle θ nonlinearly based on the first linear parameter described below. Here, in an orthogonal coordinate system in which the position of the lens 5 and the object angle θ are represented by two orthogonal axes, a curve representing the relationship between the position of the lens 5 and the object angle θ within the movable range of the lens 5 is referred to as a first curve, and a line segment connecting the two ends of the first curve is referred to as a first line segment. As described above, the relative position represents the position of the lens 5. When the movable range of the relative position is 0 to 700 μm, Fig.10 The curve with symbol 73 corresponds to the first curve, Fig.10 The line segment with reference numeral 74 corresponds to the first line segment. In addition, the value of the target angle θ corresponding to an arbitrary relative position is assumed to be a first value θ1, and the value on the first line segment corresponding to the arbitrary relative position is assumed to be a second value θ2. Fig.10 An example of the first and second values ​​θ1 and θ2 is shown in FIG.

[0107] Furthermore, let the difference between the maximum value and the minimum value of the target angle θ within the first variable range of the target angle θ be a third value Δθ. Fig.10 ] shows the third value Δθ when the movable range of the relative position is 0 to 700 μm. In addition, the ratio of the difference between the first value θ1 and the second value θ2 to the third value Δθ is defined as the first linear parameter L1. The first linear parameter L1 (unit: %) is represented by the following formula (1).

[0108] L1=(θ1-θ2) / Δθ×100…(1)

[0109] The smaller the absolute value of the first linear parameter L1, the more linearly the object angle θ changes with respect to the relative position. It can be said that if the absolute value of the first linear parameter L1 is less than 3%, the object angle θ changes linearly or approximately linearly with respect to the relative position. Therefore, in the present embodiment, the magnetic field generator 10, i.e., the first and second magnetic field generating units 11 and 12, is preferably configured such that the absolute value of the first linear parameter L1 is greater than 3%, and more preferably such that the absolute value of the first linear parameter L1 is greater than 10%, in order to make the object angle θ change nonlinearly. Fig.10 In the example shown, the absolute value of the first linear parameter L1 is 11%.

[0110] On the other hand, when the absolute value of the first linear parameter L1 is too large, the change in the object angle θ becomes larger or smaller than the change in the relative position, and it is impossible to accurately detect the position of the lens 5. In order to prevent this from happening, the magnetic field generator 10, i.e., the first and second magnetic field generating units 11 and 12, is preferably configured so that the absolute value of the first linear parameter L1 is 100% or less.

[0111] Next, the relationship between the relative position, the object angle θ, and the detection signal is described. As described above, the resistance value of the MR element 50 becomes the minimum value when the angle formed by the direction of the second magnetization of the free layer 51 relative to the direction of the first magnetization of the magnetization fixed layer 53 is 0°, and becomes the maximum value when the angle is 180°. Hereinafter, in each of the plurality of MR elements 50 included in the first resistor section R1, the angle formed by the direction of the second magnetization of the free layer 51 relative to the direction of the first magnetization of the magnetization fixed layer 53, i.e., the first direction, is referred to as the relative angle. The direction of the second magnetization of the free layer 51 changes according to the direction of the object magnetic field MF. Therefore, the relative angle changes according to the direction of the object magnetic field MF and the object angle θ.

[0112] The direction of the first magnetization of the magnetization fixed layer 53 of each of the plurality of MR elements 50 included in the fourth resistor section R4 is the same direction (first direction) as the direction of the first magnetization of the magnetization fixed layer 53 of each of the plurality of MR elements 50 included in the first resistor section R1. Therefore, in each of the plurality of MR elements 50 included in the fourth resistor section R4, the angle formed by the direction of the second magnetization of the free layer 51 with respect to the direction of the first magnetization of the magnetization fixed layer 53 is equal to or substantially equal to the relative angle.

[0113] In addition, the direction of the first magnetization of the magnetization fixed layer 53 of each of the plurality of MR elements 50 included in the second resistor section R2 is the direction (second direction) opposite to the direction of the first magnetization of the magnetization fixed layer 53 of each of the plurality of MR elements 50 included in the first resistor section R1. Therefore, in each of the plurality of MR elements 50 included in the second resistor section R2, the angle formed by the direction of the second magnetization of the free layer 51 with respect to the direction of the first magnetization of the magnetization fixed layer 53 is different from the relative angle by about 180°.

[0114] In addition, the direction of the first magnetization of the magnetization fixed layer 53 of each of the plurality of MR elements 50 included in the third resistor section R3 is the same direction (second direction) as the direction of the first magnetization of the magnetization fixed layer 53 of each of the plurality of MR elements 50 included in the second resistor section R2. Therefore, in each of the plurality of MR elements 50 included in the third resistor section R3, the angle formed by the direction of the second magnetization of the free layer 51 with respect to the direction of the first magnetization of the magnetization fixed layer 53 is different from the relative angle by about 180°.

[0115] In this embodiment, the direction of the second magnetization of the free layer 51 is set to coincide with the direction of the target magnetic field MF. Here, the angle formed by the first direction with respect to the X direction is referred to as the first angle. The relative angle is obtained by subtracting the first angle from the target angle θ.

[0116] The magnetic sensor 20 is configured such that, for example, the detection signal becomes a minimum value when the relative angle is 0°, and the detection signal becomes a maximum value when the relative angle is 180°. Fig.11 is a characteristic diagram showing the relationship between the relative angle and the detection signal. Fig.11 In , the horizontal axis represents the relative angle and the vertical axis represents the detection signal. Fig.11 In the above example, the detection signal is normalized in such a way that the maximum value of the detection signal is 1 and the minimum value of the detection signal is -1.

[0117] In the present embodiment, the detection signal changes within a second variable range corresponding to the first variable range of the object angle θ. The magnetic sensor 20 is configured so that the change in the detection signal relative to the change in the relative angle changes nonlinearly with respect to the change in the direction of the object magnetic field MF. In the present embodiment, in particular, the magnetic sensor 20 is configured so that the change in the detection signal relative to the change in the direction of the object magnetic field MF changes nonlinearly with respect to the change in the direction of the object magnetic field MF. In other words, the magnetic sensor 20 is configured so that the change in the detection signal relative to the change in the object angle θ changes nonlinearly with respect to the change in the object angle θ.

[0118] according to Fig.11 It can be understood that whether the detection signal changes linearly or nonlinearly depends on the range of the relative angle. The range of the relative angle depends on the first variable range of the object angle θ and the first angle formed by the first direction relative to the X direction. Therefore, the range of the relative angle can be adjusted according to the direction of the first magnetization of the magnetization fixed layer 53.

[0119] The magnetic sensor 20 can be configured to make the detection signal change nonlinearly based on the second linear parameter described below, for example. Here, in an orthogonal coordinate system in which the object angle θ and the detection signal are represented by two orthogonal axes, a curve representing the relationship between the object angle θ and the detection signal within the first variable range of the object angle θ is set as a second curve, and a line segment connecting the two ends of the second curve is set as a second line segment. Fig.12 is a schematic diagram showing the relationship between the object angle θ and the detection signal. Fig.12 In , the horizontal axis represents the object angle θ, and the vertical axis represents the detection signal. Fig.12 , the curve with symbol 75 represents the second curve, and the line segment with symbol 76 represents the second line segment. In addition, the value of the detection signal corresponding to the arbitrary object angle θ is set to a fourth value S1, and the value on the second line segment corresponding to the arbitrary object angle θ is set to a fifth value S2. Fig.12 An example of the fourth and fifth values ​​S1 and S2 is shown in FIG.

[0120] In addition, the difference between the maximum value and the minimum value of the detection signal within the second variable range of the detection signal is set as the sixth value ΔS. In addition, the ratio of the difference between the fourth value S1 and the fifth value S2 to the sixth value ΔS is set as the second linear parameter L2. The second linear parameter L2 (unit %) is represented by the following formula (2).

[0121] L2=(S1-S2) / ΔS×100…(2)

[0122] The smaller the absolute value of the second linear parameter L2 is, the more linearly the detection signal changes with respect to the change of the object angle θ. It can be said that if the absolute value of the second linear parameter L2 is less than 3%, the detection signal changes linearly or substantially linearly with respect to the change of the object angle θ. Therefore, in the present embodiment, the direction of the first magnetization of the magnetic sensor 20, i.e., the magnetization fixed layer 53, is preferably configured such that the absolute value of the second linear parameter L2 is 3% or more, and more preferably such that the absolute value of the second linear parameter L2 is 10% or more, so that the detection signal changes nonlinearly.

[0123] On the other hand, when the absolute value of the second linear parameter L2 is too large, the amount of change in the detection signal becomes larger or smaller than the amount of change in the object angle θ, and it is impossible to accurately detect the position of the lens 5. In order to prevent this from happening, the direction of the first magnetization of the magnetic sensor 20, i.e., the magnetization pinned layer 53 is preferably configured so that the absolute value of the second linear parameter L2 is 100% or less.

[0124] In addition, in this embodiment, the magnetic sensor 20 includes a plurality of MR elements 50. In this case, the magnetic sensor 20 can be configured so that the detection signal changes nonlinearly based on the relative angle. The relative angle can also be used together with the second linear parameter L2 as a substitute for the second linear parameter L2.

[0125] Specifically, the magnetic sensor 20, i.e., each of the plurality of MR elements 50, is configured such that the relative angle when the lens 5 is located at the center of the movable range is within a range of 0° to 70°, within a range of 110° to 250°, or within a range of 290° to less than 360°. More preferably, the relative angle when the lens 5 is located at the center of the movable range is within a range of 10° to 60°, within a range of 120° to 170°, within a range of 190° to 240°, or within a range of 300° to 350°. Fig.12 It can be understood that these ranges are ranges in which the detection signal changes nonlinearly with respect to changes in the relative angle.

[0126] As described above, the relative angle is an angle formed by the direction of the second magnetization of the free layer 51 of each of the plurality of MR elements 50 included in the first and fourth resistors R1 and R4 relative to the direction of the first magnetization of the magnetization fixed layer 53, that is, the first direction. Here, the angle formed by the direction of the second magnetization of the free layer 51 of each of the plurality of MR elements 50 included in the second and third resistors R2 and R3 relative to the direction of the first magnetization of the magnetization fixed layer 53, that is, the second direction, is referred to as the second angle. For example, when the relative angle when the lens 5 is located at the center of the movable range is in the range of 180° to 250°, the second angle when the lens 5 is located at the center of the movable range is in the range of 0° to 70°. In addition, when the relative angle when the lens 5 is located at the center of the movable range is in the range of 290° to less than 360°, the second angle when the lens 5 is located at the center of the movable range is in the range of 110° to 180°.

[0127] As described above, in the present embodiment, the magnetic field generator 10 is configured such that the direction of the target magnetic field MF changes nonlinearly with respect to the change in the position of the lens 5, and the magnetic sensor 20 is configured such that the detection signal changes nonlinearly with respect to the change in the direction of the target magnetic field MF. Thus, according to the present embodiment, the detection signal can be changed linearly with respect to the change in the position of the lens 5. That is, according to the present embodiment, even when the direction of the target magnetic field MF changes nonlinearly with respect to the change in the position of the lens 5, the detection signal can be changed linearly with respect to the change in the position of the lens 5.

[0128] Next, the effect of the position detection device 1 of the present embodiment will be described while comparing it with the position detection device of the first comparative example. First, the structure of the position detection device of the first comparative example will be described. The structure of the position detection device of the first comparative example is basically the same as the structure of the position detection device 1 of the present embodiment. However, in the first comparative example, the relative angle when the lens 5 is located at the center of the movable range is 90°.

[0129] Next, the structure of the position detection device of the first embodiment corresponding to the position detection device 1 of the present embodiment is described. The structure of the position detection device of the first embodiment is basically the same as the structure of the position detection device 1 of the present embodiment. However, in the first embodiment, the relative angle when the lens 5 is located at the center position of the movable range is 127°.

[0130] Fig.13 It is an explanatory diagram showing the directions of the first and second magnetizations in the position detection device according to the first comparative example. Fig.14It is an explanatory diagram showing the directions of the first and second magnetizations in the position detection device according to the first embodiment. Fig.13 and Fig.14 , the first and second magnetization directions of each of the plurality of MR elements 50 included in the first and fourth resistor sections R1 and R4 are shown. Fig.13 and Fig.14 In FIG. 5 , the arrow with the symbol Mp indicates the direction of the first magnetization of the magnetization fixed layer 53 (first direction), and the arrow with the symbol Mf indicates the direction of the second magnetization of the free layer 51. Fig.13 and Fig.14 In FIG. 1 , the arrow with symbol θr indicates the variable range of the direction of the first magnetization corresponding to the movable range of the lens 5 , and the dotted arrow with symbol Mf indicates the direction of the first magnetization when the lens 5 is located at the center of the movable range.

[0131] Fig.15 It is a characteristic diagram showing the relationship between relative position and relative angle. Fig.15 In the figure, the horizontal axis represents the relative position and the vertical axis represents the relative angle. Fig.15 In FIG. 7 , reference numeral 77 indicates the relative angle of the first embodiment, and reference numeral 78 indicates the relative angle of the first comparative example. In the first comparative example and the first embodiment, the movable range of the relative position is set to be in the range of 0 to 700 μm.

[0132] Here, a third linear parameter L3 is defined as a parameter indicating how the change in the detection signal corresponds to the change in the position of the lens 5, that is, the change in the relative position. The definition of the third linear parameter L3 is basically the same as that of the reference Fig.12 The definition of the second linear parameter L2 is the same as that of the second linear parameter L2. When the object angle θ and the first variable range in the description of the definition of the second linear parameter L2 are replaced with the relative position and the movable range, respectively, the description of the definition of the third linear parameter L3 is obtained. The smaller the absolute value of the third linear parameter L3 is, the more linearly the detection signal changes with respect to the change in the relative position.

[0133] Fig.16 1 is a characteristic diagram showing the relationship between the relative position, the detection signal, and the third linear parameter L3 in the position detection device of the first comparative example. Fig.17 1 is a characteristic diagram showing the relationship between the relative position, the detection signal, and the third linear parameter L3 in the position detection device of the first embodiment. Fig.16 and Fig.17 In FIG. 1 , the horizontal axis represents the relative position, the vertical axis on the left represents the detection signal, and the vertical axis on the right represents the third linear parameter L3. Fig.16 and Fig.17 In FIG. 8 , the solid line curve represents the detection signal, and the dotted line curve represents the third linear parameter L3.

[0134] like Fig.16 As shown in FIG. 1 , in the first comparative example, the maximum absolute value of the third linear parameter L3 is 11%. Fig.17 As shown, in the first embodiment, the maximum value of the absolute value of the third linear parameter L3 is 3%. Fig.16 and Fig.17 It can be understood that, compared with the first comparative example, according to the present embodiment, the detection signal can be changed linearly with respect to the change in relative position, that is, the change in the position of the lens 5 .

[0135] Next, other effects of the present embodiment are described. In the present embodiment, the relative angle when the lens 5 is located at the center of the movable range is within a range of 0° to 70°, within a range of 110° to 250°, or within a range of 290° to less than 360°. In addition, in the range of the relative angle of 0° and its vicinity, or in the range of 180° and its vicinity, the change in the detection signal becomes smaller than the change in the relative angle. In contrast, by setting the relative angle to any one of the above-mentioned preferred ranges and excluding the range of the relative angle of 0° and its vicinity, or the range of 180° and its vicinity, the change in the detection signal becomes smaller than the change in the relative angle.

[0136] In addition, in the present embodiment, the magnetic sensor 20 includes a first resistor Ro1 and a second resistor Ro2. Thus, according to the present embodiment, the offset of the detection signal can be reduced. Below, this effect is described while comparing with the position detection device of the second comparative example. First, the structure of the position detection device of the second comparative example is described. The position detection device of the second comparative example includes a magnetic sensor 120 as a substitute for the magnetic sensor 20 of the present embodiment. Fig.18 : is a circuit diagram showing the structure of the magnetic sensor 120. The first and second resistors Ro1 and Ro2 of the present embodiment are not provided in the magnetic sensor 120. The other structure of the position detection device of the second comparative example is the same as that of the position detection device 1 of the present embodiment.

[0137] Fig.19 is a characteristic diagram showing the relationship between the relative position and the detection signal in the position detection device of the second comparative example. Fig.19 In the figure, the horizontal axis represents the relative position and the vertical axis represents the detection signal. Fig.19 As shown, in the second comparative example, Fig.17 The detection signal becomes smaller than the detection signal of the first embodiment shown. Hereinafter, the deviation of the detection signal when the lens 5 is located at the center of the movable range from the predetermined reference value is referred to as the deviation of the detection signal or simply as the deviation. The predetermined reference value is, for example, 0. Fig.19 It is shown in FIG. 2 that the offset of the detection signal in the second comparative example is larger than the offset of the detection signal in the first embodiment.

[0138] The detection signal is input to a processor (not shown) and a predetermined process is performed. The processor (not shown) is composed of, for example, an application-specific integrated circuit (ASIC) or a microcomputer, and has an analog-to-digital converter (hereinafter referred to as A / D converter) for converting the detection signal into a digital signal. In the processor (not shown), the use range of the detection signal is predetermined. The use range is, for example, the range of normal input signals in the A / D converter. Fig.19 As shown in FIG. 1 , when the deviation of the detection signal is large, the value of the detection signal is not related to the second variable range and may be outside the use range. In this case, the position of the lens 5 cannot be detected.

[0139] like Fig.11 As shown in FIG. 1 , when the relative angle is 90° or 270°, the detection signal is 0. As described above, the reason why the offset of the detection signal becomes larger is that the relative angle when the lens 5 is located at the center of the movable range is an angle other than 90° and 270°. In contrast, in this embodiment, the potentials of the output ports E1 and E2 are adjusted by the first and second resistors Ro1 and Ro2, respectively, so that the offset of the detection signal becomes smaller. Therefore, according to this embodiment, it is possible to prevent the value of the detection signal from becoming outside the range of use.

[0140] [Second embodiment]

[0141] Next, a second embodiment of the present invention will be described. Fig. 20 The structure of a rotary actuator according to a second embodiment of the present invention will be described. Fig. 20 1 is a plan view showing the rotary actuator 200 .

[0142] The rotary actuator 200 of the present embodiment includes a position detection device 201 of the present embodiment, a main body 241, and a rotating body 242. The position detection device 201 of the present embodiment is a magnetic position detection device, and is used to detect the rotation position of the rotating body 242. The main body 241 includes a driving device (not shown) composed of, for example, a servo motor. The driving device (not shown) rotates the rotating body 242 in a rotation direction R around a predetermined rotation axis C. The driving device (not shown) is controlled by a control unit (not shown) outside the rotary actuator 200.

[0143] Compared with the first embodiment Figure 6 and Figure 7 same, Fig. 20 The X direction, Y direction, and Z direction are shown in FIG. In this embodiment, a direction parallel to the rotation axis C and extending from Fig. 20 The direction from the depth to the front is the Z direction. Fig. 20 , the X direction is represented as a direction toward the right, and the Y direction is represented as a direction toward the upper side.

[0144] The position detection device 201 includes a magnetic field generator 210, a magnetic sensor 220, and a connecting member 230. The connecting member 230 connects the magnetic field generator 210 and the rotating body 242. The position of the magnetic field generator 210 changes along the rotation direction R with the rotation axis C as the center as the rotating body 242 rotates. The magnetic field generator 210 generates a magnetic field (detection target magnetic field) to be detected by the magnetic sensor 220, that is, a target magnetic field. In this embodiment, the magnetic field generator 210 includes a magnet 211 that generates a target magnetic field.

[0145] The magnetic sensor 220 detects the magnetic field of the object at the detection position in the reference plane and generates a detection signal corresponding to the direction of the magnetic field of the object. The magnetic sensor 220 is fixed near the magnetic field generator 210 by a fixing member not shown. The detection position is the position where the magnetic sensor 220 detects the magnetic field of the object. The reference plane is a plane that includes the detection position and is perpendicular to the Z direction. The structure of the magnetic sensor 220 is the same as that of the magnetic sensor 20 of the first embodiment.

[0146] The magnetic field generator 210 is configured so that when the rotational position of the rotating body 242 changes, the direction and intensity of the target magnetic field at the detection position in the reference plane also change. When the position of the magnetic field generator 210 changes along with the change in the rotational position of the rotating body 242, the direction and intensity of the target magnetic field at the detection position also change, and accordingly, the value of the detection signal generated by the magnetic sensor 220 also changes. The value of the detection signal changes depending on the rotational position of the rotating body 242. The control unit (not shown) detects the rotational position of the rotating body 242 by measuring the detection signal. Similar to the magnetic sensor 20 of the first embodiment, the magnetic sensor 220 generates a detection signal corresponding to the target angle formed by the direction of the target magnetic field relative to the reference direction.

[0147] Hereinafter, the rotation position of the rotating body 242 is referred to as the rotation position. In the present embodiment, the rotation position is represented by the rotation angle of the rotating body 242, and the rotation position (rotation angle) when the rotating body 242 is located at the center of the movable range is assumed to be 0°. In addition, the rotation position is represented by a positive angle when the rotating body 242 rotates from the state where the rotation position is 0° to one direction along the rotation direction R, and is represented by a negative angle when the rotating body 242 rotates from the state where the rotation position is 0° to the direction opposite to the one direction along the rotation direction R. The movable range of the rotation position is, for example, less than 90°.

[0148] Fig.21 This is a characteristic diagram showing the relationship between the rotation position and the object angle. Fig.21 In , the horizontal axis represents the rotation position and the vertical axis represents the object angle. Fig.21In , the object angle changes with respect to the rotational position in a curve. Fig.21 In the embodiment, the object angle changes nonlinearly with respect to the change of the rotational position. The object angle changes within a first variable range corresponding to the movable range of the rotational position.

[0149] In the present embodiment, the magnetic field generator 210 is configured such that the direction of the target magnetic field changes nonlinearly with respect to the change in the rotational position. In other words, the magnetic field generator 210 is configured such that the direction of the target angle changes nonlinearly with respect to the change in the rotational position. Whether the target angle changes linearly or nonlinearly depends on, for example, the direction of magnetization of the magnet 211 of the magnetic field generator 210 or the position of the magnetic field generator 210 relative to the magnetic sensor 220.

[0150] The magnetic field generator 210 can be configured, for example, to make the object angle change nonlinearly based on the first linear parameter L1 described in the first embodiment. The first linear parameter L1 of the present embodiment is defined as follows. First, in an orthogonal coordinate system in which the rotation position and the object angle are represented by two orthogonal axes, a curve representing the relationship between the rotation position and the object angle within the movable range of the rotation position is set as a first curve, and a line segment connecting the two ends of the first curve is set as a first line segment. In addition, the value of the object angle corresponding to an arbitrary rotation position is set as a first value θ1, and the value on the first line segment corresponding to the arbitrary rotation position is set as a second value θ2. In addition, the difference between the maximum value and the minimum value of the object angle within the first variable range of the object angle is set as a third value Δθ. In addition, the ratio of the difference between the first value θ1 and the second value θ2 to the third value Δθ is set as the first linear parameter L1 corresponding to the first value θ1. The first linear parameter L1 is represented by equation (1) of the first embodiment.

[0151] In this embodiment, the magnetic field generator 210 is configured such that the absolute value of the first linear parameter L1 is 3% or more and 100% or less. Also, similar to the first embodiment, the magnetic field generator 210 is preferably configured such that the absolute value of the first linear parameter L1 is 10% or more.

[0152] In addition, as described in the first embodiment, the first and fourth resistors R1 and R4 (see Figure 7 ) includes a plurality of MR elements 50 (refer to Figure 8 ) The angle formed by the direction of the second magnetization of each free layer 51 with respect to the direction of the first magnetization of the magnetization fixed layer 53, that is, the first direction, is called a relative angle. As in the first embodiment, in this embodiment, the direction of the second magnetization of the free layer 51 is set to be consistent with the direction of the target magnetic field MF.

[0153] The magnetic sensor 220 is configured such that the change of the detection signal relative to the change of the relative angle changes nonlinearly with respect to the change of the direction of the object magnetic field. In the present embodiment, in particular, the magnetic sensor 220 is configured such that the change of the detection signal relative to the change of the direction of the object magnetic field changes nonlinearly with respect to the change of the direction of the object magnetic field. In other words, the magnetic sensor 220 is configured such that the change of the detection signal relative to the change of the object angle changes nonlinearly with respect to the change of the object angle.

[0154] As described in the first embodiment, whether the detection signal changes linearly or nonlinearly depends on the range of the relative angle. The range of the relative angle can be adjusted according to the direction of the first magnetization of the magnetization fixed layer 53.

[0155] The magnetic sensor 220 can be configured, for example, so that the detection signal changes nonlinearly based on the second linear parameter L2 described in the first embodiment. The definition of the second linear parameter L2 of this embodiment is the same as that of the first embodiment. In this embodiment, the direction of the first magnetization of the magnetic sensor 220, i.e., the magnetization fixing layer 53, is configured so that the absolute value of the second linear parameter L2 is greater than 3% and less than 100%. In addition, as in the first embodiment, the direction of the first magnetization of the magnetic sensor 220, i.e., the magnetization fixing layer 53, is preferably configured so that the absolute value of the second linear parameter L2 is greater than 10%.

[0156] In this embodiment, the magnetic sensor 220 includes a plurality of MR elements 50. In this case, the magnetic sensor 220 can be configured so that the detection signal changes nonlinearly based on the relative angle. The relative angle can also be used together with the second linear parameter L2 as a substitute for the second linear parameter L2.

[0157] Specifically, the magnetic sensor 220, i.e., each of the plurality of MR elements 50, is configured so that the relative angle when the rotating body 242 is located at the center of the movable range of the rotational position is within a range of 0° to 70°, within a range of 110° to 250°, or within a range of 290° to less than 360°. The relative angle when the rotating body 242 is located at the center of the movable range of the rotational position is more preferably within a range of 10° to 60°, within a range of 120° to 170°, within a range of 190° to 240°, or within a range of 300° to 350°.

[0158] As described above, in the present embodiment, the magnetic field generator 210 is configured such that the direction of the target magnetic field changes nonlinearly with respect to the change in the rotational position of the rotating body 242, and the magnetic sensor 220 is configured such that the detection signal changes nonlinearly with respect to the change in the direction of the target magnetic field. Thus, according to the present embodiment, the detection signal can be changed linearly with respect to the change in the position of the rotating body 242. That is, according to the present embodiment, even when the direction of the target magnetic field changes nonlinearly with respect to the change in the rotational position of the rotating body 242, the detection signal can be changed linearly with respect to the change in the rotational position of the rotating body 242.

[0159] Next, the effect of the position detection device 201 of the present embodiment will be described while comparing it with the position detection device of the third comparative example. First, the structure of the position detection device of the third comparative example will be described. The structure of the position detection device of the third comparative example is basically the same as the structure of the position detection device 201 of the present embodiment. However, in the third comparative example, the relative angle when the rotating body 242 is located at the center of the movable range is 90°. In addition, in the third comparative example, the first and second resistors Ro1 and Ro2 (see Figure 7 ).

[0160] Next, the structure of the position detection device of the second embodiment is described. The structure of the position detection device of the second embodiment is basically the same as the structure of the position detection device 201 of this embodiment. However, in the second embodiment, the relative angle when the rotating body 242 is located at the center of the movable range is 153°. In addition, in the second embodiment, the first and second resistors Ro1 and Ro2 (see Figure 7 ).

[0161] In the present embodiment, the third linear parameter L3 described in the first embodiment is used as a parameter indicating the manner in which the detection signal changes with respect to the change in the rotational position. The definition of the third linear parameter L3 is basically the same as the definition of the second linear parameter L2 described in the first embodiment. If the object angle θ and the first variable range in the description of the definition of the second linear parameter L2 are replaced with the rotational position and the movable range, respectively, the description of the definition of the third linear parameter L3 in the present embodiment becomes. The smaller the absolute value of the third linear parameter L3 is, the more linearly the detection signal changes with respect to the change in the rotational position.

[0162] Fig. 22 : is a characteristic diagram showing the relationship between the rotation position and the detection signal in the position detection device of the third comparative example. Fig.23FIG. 2 is a characteristic diagram showing the relationship between the rotation position and the detection signal in the position detection device of the second embodiment. Fig. 22 and Fig.23 In the figure, the horizontal axis represents the rotational position, and the vertical axis represents the detection signal. In the third comparative example and the second embodiment, the movable range of the rotational position is set to a range of -5° to 5°.

[0163] Fig.24 is a characteristic diagram showing the relationship between the rotation position and the third linear parameter L3. Fig.24 In , the horizontal axis represents the rotation position, and the vertical axis represents the third linear parameter L3. Fig.24 In FIG. 8 , the curve with symbol 81 represents the third linear parameter L3 of the third comparative example, and the curve with symbol 82 represents the third linear parameter L3 of the second embodiment. Fig.24 As shown, in the third comparative example, the maximum absolute value of the third linear parameter L3 is 13%, and in the second embodiment, the maximum absolute value of the third linear parameter L3 is 3%. Fig.24 It can be understood that, compared with the third comparative example, according to the present embodiment, the detection signal can be changed linearly with respect to the change in the rotational position.

[0164] The other structures, functions, and effects of this embodiment are the same as those of the first embodiment.

[0165] In addition, the present invention is not limited to the above-mentioned embodiments, and various changes can be made. As long as the requirements of the claims are met, the structures of the magnetic field generator 10, 210 and the magnetic sensors 20, 220 are not limited to the examples shown in the embodiments, and can be any structure. For example, the magnetic sensor 20, 220 includes a power port V, a ground port G, a first output port E1, a first resistor R1, a second resistor R2, and a first resistor Ro1, but can also be a structure that does not include the second output port E2, the third resistor R3, the fourth resistor R4, and the second resistor Ro2. In this case, the detection signal is a signal that depends on the potential of the first output port E1.

[0166] Alternatively, the first resistor Ro1 may be connected in series with at least one second MR element so as to be disposed between the first output port E1 and the ground port G. In this case, the second resistor Ro2 is connected in series with at least one third MR element so as to be disposed between the power supply port V and the second output port E2.

[0167] It is clear from the above description that the present invention can be implemented in various forms or variations. Therefore, within the scope of equivalents of the claims, the present invention can also be implemented in forms other than the best form described above.

Claims

1. A position detection device, It is characterized in that A position detection device for detecting the position of an object whose position can be changed. It has: a magnetic field generator that generates a target magnetic field and is configured to change the direction of the target magnetic field at a detection position within a reference plane when the position of the object changes; and a magnetic sensor that detects the magnetic field of the object and generates a detection signal corresponding to the direction of the magnetic field of the object, The magnetic field generator is configured such that the direction of the target magnetic field changes nonlinearly with respect to the position of the target object. The magnetic sensor is configured such that the detection signal changes in a manner that is nonlinear with respect to changes in the direction of the target magnetic field. The target angle formed by the direction of the target magnetic field relative to the reference direction in the reference plane changes within a first variable range corresponding to the movable range of the position of the object, The detection signal changes within a second variable range corresponding to the first variable range, In a first orthogonal coordinate system in which two orthogonal axes represent the position of the object and the object angle, when a curve representing the relationship between the position of the object within the movable range and the object angle is set as a first curve, a line segment connecting both ends of the first curve is set as a first line segment, a value of the object angle corresponding to an arbitrary position of the object is set as a first value, a value of the object angle corresponding to a point on the first line segment corresponding to the arbitrary position is set as a second value, a difference between a maximum value and a minimum value of the object angle within the first variable range is set as a third value, and a ratio of the difference between the first value and the second value to the third value is set as a first linear parameter, the magnetic field generator is configured so that the maximum value of the absolute value of the first linear parameter is greater than or equal to 3% and less than or equal to 100%, In a second orthogonal coordinate system in which the object angle and the detection signal are represented by two orthogonal axes, when a curve representing the relationship between the object angle and the detection signal within the first variable range is set as a second curve, a line segment connecting the two ends of the second curve is set as a second line segment, a value of the detection signal corresponding to an arbitrary value of the object angle is set as a fourth value, a value of the detection signal corresponding to a point on the second line segment corresponding to the arbitrary position is set as a fifth value, a difference between a maximum value and a minimum value of the detection signal within the second variable range is set as a sixth value, and a ratio of the difference between the fourth value and the fifth value to the sixth value is set as a second linear parameter, the magnetic sensor is configured so that the maximum value of the absolute value of the second linear parameter is greater than 3% and less than 100%.

2. The position detection device according to claim 1, It is characterized in that The magnetic sensor comprises at least one magnetoresistive effect element. Each of the at least one magnetoresistance effect elements includes a magnetization fixed layer having a first magnetization parallel to the reference plane and having a fixed direction, and a free layer having a second magnetization parallel to the reference plane and having a direction that can change according to the direction of the object magnetic field, and when the object is located at the center of the movable range, the angle formed by the direction of the second magnetization with respect to the direction of the first magnetization is within a range of not less than 0° and not more than 70°, within a range of not less than 110° and not more than 250°, or within a range of not less than 290° and less than 360°.

3. The position detection device according to claim 2, It is characterized in that Each of the at least one magnetoresistive effect elements is constructed in such a way that when the object is located at the center of the movable range, the angle formed by the direction of the second magnetization with respect to the direction of the first magnetization is within a range of not less than 10° and not more than 60°, within a range of not less than 120° and not more than 170°, within a range of not less than 190° and not more than 240°, or within a range of not less than 300° and not more than 350°.

4. The position detection device according to claim 2, It is characterized in that The at least one magnetoresistance effect element is at least one first magnetoresistance effect element and at least one second magnetoresistance effect element. The magnetic sensor further includes a resistor having a predetermined resistance value, a power supply port to which a predetermined voltage is applied, a ground port connected to a ground line, and an output port. The at least one first magnetoresistance effect element is arranged between the power port and the output port, The at least one second magnetoresistance effect element is arranged between the output port and the ground port, The resistor is connected in series with the at least one first magnetoresistance effect element in a manner of being arranged between the power supply port and the output port, or is connected in series with the at least one second magnetoresistance effect element in a manner of being arranged between the output port and the ground port, The direction of the first magnetization of the magnetization fixed layer of each of the at least one first magnetoresistance effect elements is a first direction, The direction of the first magnetization of the magnetization fixed layer of each of the at least one second magnetoresistance effect elements is a second direction opposite to the first direction, The detection signal depends on the potential of the output port.

5. The position detection device according to claim 2, It is characterized in that The at least one magnetoresistance effect element is at least one first magnetoresistance effect element, at least one second magnetoresistance effect element, at least one third magnetoresistance effect element and at least one fourth magnetoresistance effect element. The magnetic sensor further includes a first resistor and a second resistor each having a predetermined resistance value, a power supply port to which a predetermined voltage is applied, a ground port connected to a ground line, a first output port, and a second output port. The at least one first magnetoresistance effect element is arranged between the power port and the first output port, The at least one second magnetoresistance effect element is arranged between the first output port and the ground port, The at least one third magnetoresistance effect element is arranged between the power port and the second output port, The at least one fourth magnetoresistance effect element is arranged between the second output port and the ground port, Of the first resistor and the second resistor, the first resistor is connected in series with the at least one first magnetoresistance effect element in a manner of being arranged between the power supply port and the first output port, and the second resistor is connected in series with the at least one fourth magnetoresistance effect element in a manner of being arranged between the second output port and the ground port, or the first resistor is connected in series with the at least one second magnetoresistance effect element in a manner of being arranged between the first output port and the ground port, and the second resistor is connected in series with the at least one third magnetoresistance effect element in a manner of being arranged between the power supply port and the second output port, the first magnetization direction of the respective magnetization fixed layers of the at least one first magnetoresistance effect element and the first magnetization direction of the respective magnetization fixed layers of the at least one fourth magnetoresistance effect element are the first direction, The first magnetization direction of the magnetization fixed layer of each of the at least one second magnetoresistance effect elements and the first magnetization direction of the magnetization fixed layer of each of the at least one third magnetoresistance effect elements are a second direction opposite to the first direction, The detection signal depends on a potential difference between the first output port and the second output port.

6. The position detection device according to claim 1, It is characterized in that The position of the object changes in the direction of the straight line.

7. The position detection device according to claim 6, It is characterized in that The magnetic field generator includes a first magnetic field generating unit that generates a first magnetic field and a second magnetic field generating unit that generates a second magnetic field. The relative position of the second magnetic field generating unit with respect to the first magnetic field generating unit changes as the position of the object changes. When the component of the first magnetic field at the detection position parallel to the reference plane is assumed to be the first magnetic field component, and the component of the second magnetic field at the detection position parallel to the reference plane is assumed to be the second magnetic field component, the first magnetic field generating unit and the second magnetic field generating unit are configured in such a way that when the relative position of the second magnetic field generating unit with respect to the first magnetic field generating unit changes, the intensity of the first magnetic field component and the direction of the first magnetic field component and the direction of the second magnetic field component do not change, but the intensity of the second magnetic field component changes, The target magnetic field is a composite magnetic field of the first magnetic field component and the second magnetic field component.

8. The position detection device according to claim 7, It is characterized in that The first magnetic field generating unit includes two magnets arranged at different positions from each other. The first magnetic field is a magnetic field obtained by synthesizing two magnetic fields respectively generated by the two magnets.

9. The position detection device according to claim 8, It is characterized in that Also available: a first holding member that holds the first magnetic field generating unit; and The second holding member is provided so as to be positionally changeable in one direction relative to the first holding member and holds the second magnetic field generating unit.

10. The position detection device according to claim 9, It is characterized in that The object is a lens, The second holding member is a member that holds the lens, and is provided so as to be positionally changeable in the optical axis direction of the lens relative to the first holding member.

11. The position detection device according to claim 1, It is characterized in that The object is a rotating body whose position changes along a rotation direction around a central axis.

12. The position detection device according to claim 11, It is characterized in that The magnetic field generator is connected to the rotating body.

13. A camera module, It is characterized in that have: A lens, the position of which can be varied in the direction of the line; A position detection device, used to detect the position of the lens; a holding member that holds the lens; and a drive device that moves the holding member, The position detection device comprises: a magnetic field generator that generates a target magnetic field and is configured to change the direction of the target magnetic field at a detection position in a reference plane when the position of the lens changes; and a magnetic sensor that detects the magnetic field of the object and generates a detection signal corresponding to the direction of the magnetic field of the object, The magnetic field generator is configured such that the direction of the target magnetic field changes nonlinearly with respect to the position of the lens. The magnetic sensor is configured such that the detection signal changes in a manner that is nonlinear with respect to changes in the direction of the target magnetic field. The target angle formed by the direction of the target magnetic field relative to the reference direction in the reference plane changes within a first variable range corresponding to the movable range of the position of the lens, The detection signal changes within a second variable range corresponding to the first variable range, In a first orthogonal coordinate system in which two orthogonal axes represent the position of the lens and the object angle, when a curve representing the relationship between the position of the lens within the movable range and the object angle is set as a first curve, a line segment connecting both ends of the first curve is set as a first line segment, a value of the object angle corresponding to an arbitrary position of the lens is set as a first value, a value of the object angle corresponding to a point on the first line segment corresponding to the arbitrary position is set as a second value, a difference between a maximum value and a minimum value of the object angle within the first variable range is set as a third value, and a ratio of the difference between the first value and the second value to the third value is set as a first linear parameter, the magnetic field generator is configured so that the maximum value of the absolute value of the first linear parameter is greater than or equal to 3% and less than or equal to 100%, In a second orthogonal coordinate system in which the object angle and the detection signal are represented by two orthogonal axes, when a curve representing the relationship between the object angle and the detection signal within the first variable range is set as a second curve, a line segment connecting the two ends of the second curve is set as a second line segment, a value of the detection signal corresponding to an arbitrary value of the object angle is set as a fourth value, a value of the detection signal corresponding to a point on the second line segment corresponding to the arbitrary position is set as a fifth value, a difference between a maximum value and a minimum value of the detection signal within the second variable range is set as a sixth value, and a ratio of the difference between the fourth value and the fifth value to the sixth value is set as a second linear parameter, the magnetic sensor is configured so that the maximum value of the absolute value of the second linear parameter is greater than 3% and less than 100%.

14. A rotary actuator comprising: A rotating body, the position of which can be changed along the direction of rotation around the central axis; a position detection device for detecting the position of the rotating body; and a driving device that causes the rotating body to rotate, The position detection device comprises: a magnetic field generator that generates a target magnetic field and is configured to change the direction of the target magnetic field at a detection position within a reference plane when the position of the rotating body changes; and a magnetic sensor that detects the magnetic field of the object and generates a detection signal corresponding to the direction of the magnetic field of the object, The magnetic field generator is configured such that the direction of the target magnetic field changes nonlinearly with respect to the position of the rotating body. The magnetic sensor is configured such that the detection signal changes in a manner that is nonlinear with respect to changes in the direction of the target magnetic field. The target angle formed by the direction of the target magnetic field relative to the reference direction in the reference plane changes within a first variable range corresponding to the movable range of the position of the rotating body. The detection signal changes within a second variable range corresponding to the first variable range, In a first orthogonal coordinate system in which two orthogonal axes represent the position of the rotating body and the object angle, when a curve representing the relationship between the position of the rotating body within the movable range and the object angle is set as a first curve, a line segment connecting both ends of the first curve is set as a first line segment, a value of the object angle corresponding to an arbitrary position of the rotating body is set as a first value, a value of the object angle corresponding to a point on the first line segment corresponding to the arbitrary position is set as a second value, a difference between a maximum value and a minimum value of the object angle within the first variable range is set as a third value, and a ratio of the difference between the first value and the second value to the third value is set as a first linear parameter, the magnetic field generator is configured so that the maximum value of the absolute value of the first linear parameter is greater than 3% and less than 100%, In a second orthogonal coordinate system in which the object angle and the detection signal are represented by two orthogonal axes, when a curve representing the relationship between the object angle and the detection signal within the first variable range is set as a second curve, a line segment connecting the two ends of the second curve is set as a second line segment, a value of the detection signal corresponding to an arbitrary value of the object angle is set as a fourth value, a value of the detection signal corresponding to a point on the second line segment corresponding to the arbitrary position is set as a fifth value, a difference between a maximum value and a minimum value of the detection signal within the second variable range is set as a sixth value, and a ratio of the difference between the fourth value and the fifth value to the sixth value is set as a second linear parameter, the magnetic sensor is configured so that the maximum value of the absolute value of the second linear parameter is greater than 3% and less than 100%.

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