Driving device, camera module, and camera mounting device

Abstract

A driving device comprising: a lens holder; a magnet holder; a coil part; and an imaging element holding part. An OIS magnet includes a first magnet and at least two second magnets arranged so as to be adjacent to an AF magnet, with the second magnets being disposed so as to sandwich each magnetic pole of the first magnet.

Description

Drive device, camera module, and camera-mounted device

[0001] The present invention relates to a driving device, a camera module, and a camera-mounted device.

[0002] Generally, mobile terminals such as smartphones are equipped with a small camera module. Such a camera module is equipped with a lens driving device having an autofocus function (hereinafter referred to as the “AF function”) that automatically performs autofocus when photographing a subject, and an image stabilization function (hereinafter referred to as the “OIS function”) that optically corrects shake (vibration) that occurs during photographing to reduce image distortion.

[0003] The lens driving device having an AF function and an OIS function includes an autofocus driving unit (hereinafter referred to as an "AF driving unit") for moving the lens unit in the optical axis direction, and an image stabilization driving unit (hereinafter referred to as an "OIS driving unit") for oscillating the lens unit in a plane perpendicular to the optical axis direction. In Patent Document 1, a voice coil motor (VCM) is used for the AF driving unit and the OIS driving unit.

[0004] An autofocus movable part (hereinafter referred to as "AF movable part") that can move in the optical axis direction during autofocusing is disposed, for example, spaced apart in the radial direction from an autofocus fixed part (hereinafter referred to as "AF fixed part"). An image stabilization movable part (hereinafter referred to as "OIS movable part") that swings in a plane perpendicular to the optical axis during image stabilization is composed of an AF unit including an AF movable part, an AF fixed part, and an AF drive part, and is disposed, for example, spaced apart in the optical axis direction from the image stabilization fixed part (hereinafter referred to as "OIS fixed part"). The OIS movable part is connected to the OIS fixed part by an OIS support part such as a suspension wire, and is capable of swinging in a plane perpendicular to the optical axis.

[0005] In addition, the AF drive unit and the OIS drive unit are each provided with a coil and a magnet. The magnet serves both as a magnet for AF drive and a magnet for OIS drive, and is positioned so as to face both the AF coil and the OIS coil. Specifically, one of the AF coil and the OIS coil faces the magnet in a direction along which the south and north poles are aligned (for example, the horizontal direction). The other of the AF coil and the OIS coil faces the magnet in a direction different from the horizontal direction (for example, the vertical direction).

[0006] JP 2013-210550 A

[0007] Since magnetic flux flows in the horizontal direction of the magnet, a sufficient amount of magnetic flux flows through the coils facing each other in the horizontal direction, allowing the drive units corresponding to those coils to be driven with sufficient thrust.

[0008] However, for a coil facing the magnet in a vertical direction different from the horizontal direction, magnetic flux flows from the north pole to the south pole located on the opposite side, resulting in more magnetic flux flowing horizontally rather than vertically through the coil. In other words, the amount of magnetic flux flowing in a direction different from the direction of facing the magnet is greater in the coil. Since such magnetic flux is difficult to utilize for the operation of the drive unit (e.g., OIS operation), it may be impossible to drive the drive unit corresponding to the coil with sufficient thrust. In other words, the configuration described in Patent Document 1 leaves room for improvement in terms of improving the thrust of the drive operations of both the AF drive unit and the OIS drive unit.

[0009] An object of the present invention is to provide a drive device, a camera module, and a camera-mounted device that can improve the thrust of the drive operations of both the AF drive unit and the OIS drive unit.

[0010] a drive unit having the magnet portion and a coil portion; and an image sensor holding unit that holds an image sensor facing the lens in the optical axis direction, wherein the magnet portion has an autofocus magnet for driving the lens holder in the optical axis direction, and a shake correction magnet for driving the lens holder or the image sensor holding unit in a direction orthogonal to the optical axis direction, the coil portion has an autofocus coil facing the autofocus magnet, and a shake correction coil facing the shake correction magnet, the shake correction magnet has a first magnet and a second magnet that are arranged adjacent to the autofocus magnet in the optical axis direction, the first magnet is arranged so that its magnetic poles are aligned in the same direction as the magnetic poles of the autofocus magnet, and the second magnet is arranged so that its magnetic poles are aligned in a direction orthogonal to the magnetic poles of the autofocus magnet, At least two of the first magnets are provided so as to sandwich each magnetic pole of the first magnet.

[0011] A camera module according to the present invention includes: the driving device; an element section including the lens; and an imaging section including the imaging element that captures a subject image formed by the element section.

[0012] A camera-equipped device according to the present invention is an information device or transportation device, and includes the camera module described above, and an imaging control unit that processes image information obtained by the camera module.

[0013] According to the present invention, it is possible to improve the thrust force of the drive operations of both the AF drive unit and the OIS drive unit.

[0014] 1 is a diagram showing a smartphone equipped with a camera module. FIG. 2 is a diagram showing a smartphone equipped with a camera module. FIG. 3 is an external perspective view of the camera module. FIG. 4 is a perspective view showing a state in which the cover of the lens driving device is removed. FIG. 5 is an exploded perspective view showing a schematic configuration of the lens driving device. FIG. 6 is an exploded perspective view showing a detailed configuration of the lens driving device. FIG. 7 is an exploded perspective view showing a detailed configuration of the lens driving device. FIG. 8 is a diagram showing the lens driving device as viewed from the optical axis direction. FIG. 9 is a perspective view of a driving magnet. FIG. 10 is an exploded perspective view of a driving magnet. FIG. 11 is a simplified cross-sectional view of a driving magnet portion of the lens driving device. FIG. 12 is a diagram for explaining the positional relationship between the driving magnet and a coil portion. FIG. 13 is a diagram for explaining the flow of magnetic flux in a driving magnet in a conventional example. FIG. 14 is a diagram for explaining the flow of magnetic flux in a driving magnet in the present embodiment. FIG. 15 is a simplified cross-sectional view of a driving magnet portion of a lens driving device according to a sensor shift type configuration. FIG. 16 is a diagram showing a car equipped with a camera module. FIG. 17 is a diagram showing a car equipped with a camera module.

[0015] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0016] 1A and 1B are diagrams showing a smartphone M (an example of a camera-equipped device) equipped with a camera module A according to an embodiment of the present invention, in which Fig. 1A is a front view of the smartphone M and Fig. 1B is a rear view of the smartphone M.

[0017] In this embodiment, the camera module A is applied to the rear camera OC1 of the smartphone M. The camera module A has an AF function and an OIS function, and can automatically perform autofocus when photographing a subject, and can optically correct shake (vibration) that occurs during photography to capture images without image blur.

[0018] Fig. 2 is a perspective view of the appearance of the camera module A. As shown in Fig. 2, the embodiment will be described using a Cartesian coordinate system (X, Y, Z). The same Cartesian coordinate system (X, Y, Z) is also used in the figures described below. Furthermore, the intermediate directions that form 45° with the X direction and the Y direction, i.e., the diagonal directions in the planar view of the camera module A when viewed from the optical axis direction, will be described as the U direction and the V direction.

[0019] When actually taking a photograph with the smartphone M, the camera module A is mounted so that the X direction is the up-down direction (or left-right direction), the Y direction is the left-right direction (or up-down direction), and the Z direction is the front-to-back direction. That is, the Z direction is the optical axis direction, and the upper side in the drawing is the optical axis direction light receiving side (also referred to as the "macro position side"), and the lower side is the optical axis direction image forming side (also referred to as the "infinity position side"). Furthermore, the X direction and Y direction perpendicular to the Z axis are referred to as the "optical axis perpendicular direction."

[0020] The camera module A includes a lens driving device 1 that realizes AF and OIS functions, a lens unit 2 in which a lens is housed in a cylindrical lens barrel, and an imaging unit 3 that captures the subject image formed by the lens unit 2.

[0021] The imaging unit 3 is disposed on the imaging side of the lens driving device 1 in the optical axis direction. The imaging unit 3 includes, for example, an image sensor board 41, an imaging element 42, and a control unit 43 that controls the driving of the lens driving device 1. The lens driving device 1 is mounted on the image sensor board 41 and mechanically and electrically connected thereto. The imaging element 42 is configured, for example, by a charge-coupled device (CCD) image sensor or a complementary metal oxide semiconductor (CMOS) image sensor. The imaging element 42 is mounted on the image sensor board 41 and captures an image of a subject formed by the lens unit 2. The control unit 43 controls the driving of the lens driving device 1. The control unit 43 may be mounted on the image sensor board 41 or may be provided in a camera-equipped device (in this embodiment, a smartphone M) in which the camera module A is mounted.

[0022] As shown in FIG. 3 , the lens driving device 1 has a driving device main body (reference numeral omitted) that is covered on the outside with a cover 25. The cover 25 is a covered square cylinder that is rectangular in plan view from the optical axis direction, and has an opening 251 on its top surface. The lens unit 2 faces the outside through this opening 251. The cover 25 is fixed to the base 21 of the lens driving device 1, for example, by adhesive. That is, the lens driving device 1 has a rectangular shape that extends in the X and Y directions in plan view from the optical axis direction. In the following description, "plan view" means a plan view from the optical axis direction.

[0023] Fig. 4 is an exploded perspective view showing the schematic configuration of the lens driving device 1. Figs. 5 and 6 are exploded perspective views showing the detailed configuration of the lens driving device 1. Note that the cover 25 is omitted in Figs. 4 to 6.

[0024] Functionally, as shown in FIG. 4, the lens driving device 1 includes an OIS movable part M1, an OIS fixed part F1, an OIS driving part D1, an OIS support part S1, an AF movable part M2, an AF fixed part F2, an AF driving part D2, and an AF support part S2.

[0025] The OIS movable part M1 is a part that receives the driving force of the OIS driving part D1 and oscillates in a plane perpendicular to the optical axis during shake correction, and in this embodiment is composed of an AF unit including an AF movable part M2, an AF fixed part F2, an AF driving part D2, and an AF support part S2.

[0026] The OIS fixed portion F1 is a portion that supports the OIS movable portion M1, and in this embodiment is formed by a base 21. The OIS fixed portion F1 is disposed, for example, at a distance from the OIS movable portion M1 on the imaging side in the optical axis direction.

[0027] The OIS support portion S1 is a portion that connects the OIS movable portion M1 and the OIS fixed portion F1, and supports the OIS movable portion M1 so that it can swing within a plane perpendicular to the optical axis. In this embodiment, the OIS support portion S1 is made up of suspension wires 24 that are arranged at the four corners.

[0028] OIS driving unit D1 is composed of OIS coils 23A-23D arranged on OIS fixed unit F1 and driving magnets 14A-14D (OIS magnets) arranged on OIS movable unit M1. In other words, a moving magnet type voice coil motor is applied to OIS driving unit D1. Note that OIS driving unit D1 may also be composed of a moving coil type voice coil motor.

[0029] The AF movable portion M2 is a portion that receives the driving force of the AF driving portion D2 and moves in the optical axis direction during autofocusing, and is formed by the lens holder 11 in this embodiment.

[0030] The AF fixed portion F2 is a portion that supports the AF movable portion M2, and in this embodiment, is configured by a magnet holder 12. The AF fixed portion F2 is disposed, for example, radially outwardly and spaced apart from the AF movable portion M2.

[0031] The AF support part S2 is a part that connects the AF movable part M2 and the AF fixed part F2, and in this embodiment, it is composed of an upper elastic support member 15 that is arranged on the light receiving side (upper side) in the optical axis direction, and a lower elastic support member 16 that is arranged on the imaging side (lower side) in the optical axis direction.

[0032] The AF drive unit D2 is a part that drives the AF movable unit M2 during autofocusing, and in this embodiment is composed of an AF coil 13 arranged in the AF movable unit M2 and drive magnets 14A to 14D (AF magnets) arranged in the AF fixed unit F2. That is, a moving coil type voice coil motor is applied to the AF drive unit D2 in this embodiment. Note that the AF drive unit D2 may also be composed of a moving magnet type voice coil motor.

[0033] A guaranteed stroke, which indicates the degree to which shake correction can be performed appropriately, is defined for the lens driving device 1. That is, the shapes, sizes, strengths, etc. of the constituent members of the OIS movable part M1, OIS fixed part F1, OIS driving part D1, and OIS support part S1 are set so as to realize the guaranteed stroke.

[0034] Structurally, as shown in Figures 5 and 6, the lens driving device 1 has a lens holder 11, a magnet holder 12, an AF coil 13, driving magnets 14A to 14D, an upper elastic support member 15, a lower elastic support member 16, a base 21, a coil substrate 22, OIS coils 23A to 23D, and a suspension wire 24.

[0035] The lens holder 11 is a member that functions as the AF movable portion M2, and holds the lens portion 2 (see FIG. 2) in a cylindrical lens housing portion 111. The lens portion 2 is fixed to the lens housing portion 111 by adhesive or screwing. In this embodiment, the lens holder 11 has a roughly octagonal outer shape in a plan view. An AF coil 13 is attached to the peripheral surface of the lens holder 11.

[0036] The lens holder 11 has, on its top surface (the upper end surface of the lens housing portion 111), an upper spring fixing portion 112 to which the upper elastic support member 15 is fixed. The upper spring fixing portion 112 is provided with, for example, a positioning boss (reference number omitted) that protrudes toward the light receiving side in the optical axis direction, and the upper elastic support member 15 is positioned by this positioning boss.

[0037] The lens holder 11 has, on its lower surface, a lower spring fixing portion 113 to which the lower elastic support member 16 is fixed. The lower spring fixing portion 113 is provided with, for example, a positioning boss (reference number omitted) that protrudes toward the imaging side in the optical axis direction, and the lower elastic support member 16 is positioned by this positioning boss.

[0038] The lens holder 11 also has, on its upper surface, a tethering portion 114 to which an end of the AF coil 13 is connected. The lens holder 11 also has a protrusion 115 that protrudes radially outward on the upper outer circumferential surface of the lens housing portion 111. In this embodiment, the protrusions 115 are provided at four locations that face each other in the X and Y directions.

[0039] The magnet holder 12 is a holding member having a generally rectangular cylindrical shape in plan view, with four connected side walls 122. The magnet holder 12 has an opening 121 cut out in a portion corresponding to the generally octagonal outer shape of the lens holder 11 in plan view.

[0040] The magnet holder 12 has magnet holding portions 123 inside the connecting portions (four corners of the magnet holder 12) of the four side wall bodies 122. The drive magnets 14A to 14D are fixed to the magnet holding portions 123. For example, the magnet holding portions 123 are provided with openings (reference numeral omitted) that communicate with the outside, so that adhesive can be injected onto the contact surfaces between the magnet holding portions 123 and the drive magnets 14A to 14D.

[0041] The magnet holder 12 has a wire insertion portion 124 that is recessed in an arc shape radially inward, above the connecting portion, on the outer circumferential surface of the side wall body 122. The suspension wire 24 is disposed in the wire insertion portion 124. By providing the wire insertion portion 124, it is possible to avoid interference between the suspension wire 24 and the magnet holder 12 when the OIS movable part M1 swings.

[0042] The magnet holder 12 has an upper spring fixing portion 126 for fixing the upper elastic support member 15 on the upper surface of the side wall body 122. In the upper spring fixing portion 126, the peripheral edge of the wire insertion portion 124 is recessed below the mounting surface of the upper elastic support member 15, so that a gap is formed when the upper elastic support member 15 is mounted.

[0043] The magnet holder 12 also has a lower spring fixing portion 127 on the lower surface of the side wall 122 for fixing the lower elastic support member 16 .

[0044] The magnet holder 12 has a recess 125 recessed from the light receiving side toward the imaging side in the optical axis direction at a position corresponding to the protrusion 115 of the lens holder 11 on the upper part of the side wall 122. When the lens holder 11 moves toward the imaging side in the optical axis direction, the protrusion 115 of the lens holder 11 engages with the recess 125 of the magnet holder 12, thereby restricting the movement of the lens holder 11 toward the imaging side in the optical axis direction.

[0045] Furthermore, a plurality of protrusions 128 that protrude toward the light receiving side in the optical axis direction are provided on the top surface of the magnet holder 12. Providing the protrusions 128 makes it possible to prevent direct collision between the cover 25 and the main parts of the lens driving device 1 when an external force in the optical axis direction is applied due to a fall or the like, thereby suppressing failure of the lens driving device 1.

[0046] Furthermore, the magnet holder 12 has a movable-side restricting portion 129 that restricts the movement of the OIS movable portion M1 in the U and V directions.

[0047] The AF coil 13 is an air-core coil that is energized during autofocusing, and is wound around the outer circumferential surface of the coil winding portion of the lens holder 11. The AF coil 13, together with the drive magnets 14A to 14D, constitutes a voice coil motor that functions as the AF drive unit D2. Both ends of the AF coil 13 are respectively wound around the winding portion 114 of the lens holder 11. Electricity is supplied to the AF coil 13, for example, via the suspension wire 24 and the upper elastic support member 15. The current flowing through the AF coil 13 is controlled, for example, by the control unit 43.

[0048] The drive magnets 14A to 14D are fixed to the magnet holding portion 123 of the magnet holder 12, for example, by adhesive. In this embodiment, the drive magnets 14A to 14D have a generally isosceles trapezoidal shape in a plan view. This allows the space at the corners of the magnet holder 12 (the magnet holding portion 123) to be used effectively.

[0049] The drive magnets 14A to 14D are disposed so as to be spaced apart in the radial direction from the AF coil 13 and spaced apart in the optical axis direction from the OIS coils 23A to 23D. The drive magnets 14A to 14D are magnetized so as to form a magnetic field that crosses the AF coil 13 in the radial direction (U direction or V direction) and crosses the OIS coils 23A to 23D in the optical axis direction (Z direction). The drive magnets 14A to 14D, together with the AF coil 13, constitute a voice coil motor that functions as the AF drive unit D2. The drive magnets 14A to 14D correspond to the "magnet unit" of the present invention. Details of the drive magnets 14A to 14D will be described later.

[0050] The upper elastic support member 15 elastically supports the lens holder 11, which is the AF movable part M2, on the light-receiving side in the optical axis direction relative to the magnet holder 12, which is the AF fixed part F2. The upper elastic support member 15 is formed, for example, from titanium copper, nickel copper, stainless steel, or the like. The upper elastic support member 15 has a rectangular shape in a plan view as a whole, i.e., the same shape as the magnet holder 12. The upper elastic support member 15 is composed of two leaf springs and is arranged on the magnet holder 12 so as not to contact each other. The upper elastic support member 15 is formed, for example, by etching a single piece of sheet metal.

[0051] The upper elastic support member 15 has a lens holder fixing portion 151 fixed to the lens holder 11, a magnet holder fixing portion 152 fixed to the magnet holder 12, and an arm portion 153 that elastically deforms as the lens holder 11 moves.

[0052] The lens holder fixing portion 151 has a shape corresponding to the upper spring fixing portion 112 of the lens holder 11. The lens holder fixing portion 151 is displaced together with the lens holder 11 when the lens holder 11 moves in the optical axis direction. The magnet holder fixing portion 152 has a shape corresponding to the upper spring fixing portion 126 of the magnet holder 12. The arm portion 153 connects the lens holder fixing portion 151 and the magnet holder fixing portion 152. The arm portion 153 has a winding shape and is easily elastically deformed when the lens holder 11 moves.

[0053] The upper elastic support member 15 is positioned relative to the lens holder 11 and the magnet holder 12 and fixed by, for example, adhesive. A portion of the lens holder fixing portion 151 is electrically connected, for example, by soldering, to the AF coil 13 that is wound around the winding portion 114 of the lens holder 11. In addition, an end (corner) of the magnet holder fixing portion 152 is connected to the suspension wire 24 (wire connecting portion 154). The upper elastic support member 15, together with the suspension wire 24, forms a power supply path from the terminal fitting 27 to the AF coil 13.

[0054] The lower elastic support member 16 elastically supports the lens holder 11, which is the AF movable part M2, on the imaging side in the optical axis direction relative to the magnet holder 12, which is the AF fixed part F2. The lower elastic support member 16 is formed, for example, from titanium copper, nickel copper, stainless steel, etc. The lower elastic support member 16 has a rectangular shape as a whole in a plan view, i.e., the same shape as the magnet holder 12. The lower elastic support member 16 is formed, for example, by etching a single piece of sheet metal.

[0055] The lower elastic support member 16 has a lens holder fixing portion 161 fixed to the lens holder 11, a magnet holder fixing portion 162 fixed to the magnet holder 12, and an arm portion 163 that elastically deforms as the lens holder 11 moves.

[0056] The lens holder fixing portion 161 has a shape corresponding to the lower spring fixing portion 113 of the lens holder 11. The lens holder fixing portion 161 is displaced together with the lens holder 11 when the lens holder 11 moves in the optical axis direction. The magnet holder fixing portion 162 has a shape corresponding to the upper spring fixing portion 126 of the magnet holder 12. The arm portion 163 connects the lens holder fixing portion 161 and the magnet holder fixing portion 162. The arm portion 163 has a winding shape and is easily elastically deformed when the lens holder 11 moves.

[0057] The lower elastic support member 16 is positioned relative to the lens holder 11 and the magnet holder 12 and fixed thereto by, for example, adhesive.

[0058] The base 21 has a rectangular shape in a plan view, with a circular opening 211 formed in the center. In the camera module A, an image sensor board 41 on which an image sensor 42 is mounted is disposed on the image forming side of the base 21 in the optical axis direction. The base 21 corresponds to the "image sensor holding portion" of the present invention.

[0059] Terminal fittings 26 and 27 are embedded in the base 21 by, for example, insert molding.

[0060] The terminal fittings 26 are electrically connected to the wiring pattern of the image sensor board 41, and form power lines for supplying power to the OIS coils 23A to 23D and the magnetic sensors 31A and 31B, as well as signal lines for the detection signals output from the magnetic sensors 31A and 31B.

[0061] The terminal fittings 27 are exposed from the four corners of the base 21 and are connected by soldering to the other ends of the suspension wires 24. Two of the four terminal fittings 27 are electrically connected to the wiring pattern of the image sensor board 41 and form a power supply line for supplying power to the AF coil 13.

[0062] The base 21 also has a fixed-side restricting portion 212. The fixed-side restricting portion 212, together with the movable-side restricting portion 129 of the magnet holder 12, restricts the movement of the OIS movable portion M1 in the U and V directions.

[0063] Coil substrate 22 is a substrate that is rectangular in plan view, similar to base 21, and has a circular opening 221 in the center. Coil substrate 22 has a wiring pattern (not shown) that includes power lines for supplying power to OIS coils 23A to 23D and magnetic sensors 31A, 31B, and signal lines for detection signals output from magnetic sensors 31A, 31B. The wiring pattern is electrically connected to terminal fittings 26 arranged on base 21.

[0064] OIS coils 23A to 23D are disposed in positions facing drive magnets 14A to 14D in the optical axis direction. OIS coils 23A to 23D are fabricated inside coil substrate 22, for example, during the manufacturing process of coil substrate 22.

[0065] The OIS coils 23A-23D are air-core coils that are energized during shake correction. The sizes and arrangements of the OIS coils 23A-23D and the drive magnets 14A-14D are set so that the radial edges of the drive magnets 14A-14D fit within the cross-sectional width of each of the OIS coils 23A-23D, i.e., so that the magnetic field radiated from the bottom surfaces of the drive magnets 14A-14D crosses two opposing sides of the OIS coils 23A-23D and returns to the drive magnets 14A-14D. Here, the OIS coils 23A-23D have a shape similar to the planar shape of the drive magnets 14A-14D (here, a substantially isosceles trapezoidal shape). This allows for efficient generation of a drive force (electromagnetic force) for oscillating the OIS movable part M1 in a plane perpendicular to the optical axis. The current flowing through the OIS coils 23A-23D is controlled, for example, by the control unit 43.

[0066] OIS coils 23A and 23C arranged opposite each other in the U direction and OIS coils 23B and 23D arranged opposite each other in the V direction are connected together and the same current is passed through them. Drive magnets 14A and 14C and OIS coils 23A and 23C form an OIS voice coil motor that swings OIS movable part M1 in the U direction. Drive magnets 14B and 14D and OIS coils 23B and 23D form an OIS voice coil motor that swings OIS movable part M1 in the V direction.

[0067] Magnetic sensors 31A and 31B are mounted on the underside of coil substrate 22. Magnetic sensors 31A and 31B are formed, for example, by Hall elements or TMR (Tunnel Magneto Resistance) sensors, and are disposed in positions facing drive magnets 14A and 14B, respectively, in the optical axis direction. In the present embodiment, magnetic sensors 31A and 31B are disposed on the backsides of the air-core portions of OIS coils 23A and 23B, respectively.

[0068] The magnetic field formed by the drive magnets 14A and 14B is detected by the magnetic sensors 31A and 31B, thereby enabling the position of the OIS movable part M1 to be identified in a plane perpendicular to the optical axis. That is, in this embodiment, the magnetic sensors 31A and 31B and the drive magnets 14A and 14B constitute an XY position detection part. Note that, a magnet for detecting the XY position of the OIS movable part M1 may be disposed on the OIS movable part M1 separately from the drive magnets 14A and 14B. That is, in this embodiment, the drive magnets 14A and 14B also serve as magnets for detecting the XY position.

[0069] The suspension wires 24 are linear members extending in the optical axis direction and elastically deform in response to the swinging of the OIS movable part M1. One end of the suspension wires 24 (the end on the light-receiving side in the optical axis direction, the upper end) is fixed to the OIS movable part M1 (the upper elastic support member 15 in this embodiment), and the other end (the end on the imaging side in the optical axis direction) is fixed to the OIS fixed part F1 (the base 21 in this embodiment). In this embodiment, two of the four suspension wires 24, together with the upper elastic support member 15, are used as a power supply path to the AF coil 13.

[0070] When shake correction is performed in lens driving device 1, current is passed through OIS coils 23A to 23D. Specifically, the OIS driving unit controls the current passing through OIS coils 23A to 23D based on a detection signal from a shake detection unit (not shown, for example, a gyro sensor) so as to cancel out shake of camera module A. At this time, by feeding back the detection results of magnetic sensors 31A and 31B, it is possible to accurately control the swing of OIS movable part M1.

[0071] When current is applied to OIS coils 23A to 23D, a Lorentz force is generated in OIS coils 23A to 23D due to the interaction between the magnetic field of drive magnets 14A to 14D and the current flowing through OIS coils 23A to 23D (Fleming's left-hand rule). The direction of the Lorentz force is a direction (V direction or U direction) that is perpendicular to the direction of the magnetic field (Z direction) and the direction of the current (U direction or V direction) in the long sides of OIS coils 23A to 23D. Because OIS coils 23A to 23D are fixed, a reaction force acts on drive magnets 14A to 14D. This reaction force becomes the driving force for the OIS voice coil motor, and OIS movable part M1 having drive magnets 14A to 14D oscillates in the XY plane, thereby performing shake correction.

[0072] Next, the drive magnets 14A to 14D will be described in detail. Because the drive magnets 14A to 14D each have the same configuration, the reference numerals A, B, C, and D will be omitted in the following description unless otherwise specified. Figure 7 is a view of the lens drive device 1 as seen from the optical axis direction (Z direction). Note that in Figure 7, the lens holder 11, magnet holder 12, etc. are omitted in order to show the positional relationship between the drive magnet 14, the AF coil 13, and the OIS coil.

[0073] 7, the four drive magnets 14 are held by magnet holders 12 (not shown) so as to be located at positions corresponding to the four corners of the rectangular base 21. Specifically, two drive magnets 14 are arranged on each of the diagonal lines along the U direction and the V direction of the rectangular shape of the base 21.

[0074] As shown in FIGS. 8A, 8B, and 9, the drive magnet 14 has an AF (autofocus) magnet 141, an OIS (image stabilizer) magnet 142, and a cover portion 143.

[0075] The AF magnets 141 are used to drive the lens holder 11 in the optical axis direction (Z direction), and together with the AF coil 13, constitute the AF drive unit D2. As described above, each of the four AF magnets 141 is configured in a substantially isosceles trapezoidal shape in a plan view, and is disposed so as to face the outer circumferential surface of the AF coil 13. In other words, the four AF magnets 141 are disposed so as to surround the AF coil 13 on all sides.

[0076] The AF magnet 141 is composed of a single-pole magnet. The AF magnet 141 is magnetized so that a side 141A facing the AF coil 13 is an N pole and a side 141B not facing the AF coil is an S pole in the direction facing the AF coil 13. In other words, the AF magnet 141 is arranged so that its magnetic poles are aligned in a direction (U direction or V direction) along an XY plane (plane orthogonal to the optical axis) that is orthogonal to the Z direction.

[0077] Specifically, two AF magnets 141 arranged diagonally along the U direction are arranged so that their magnetic poles are aligned in the U direction, and two AF magnets 141 arranged diagonally along the V direction are arranged so that their magnetic poles are aligned in the V direction. 8A, 8B, and 9 show examples in which the AF magnets 141 are arranged so that their magnetic poles are aligned in the U direction.

[0078] The phrase "magnetic poles are aligned" used here means that paired magnetic poles (north and south poles) are aligned.

[0079] OIS magnet 142 is used to drive lens holder 11 in a direction along the XY plane (a direction perpendicular to the optical axis), and together with OIS coils 23A to 23D constitutes OIS drive unit D1. Note that, because OIS coils 23A to 23D each have the same configuration, in the following description, the reference characters A, B, C, and D will be omitted unless otherwise specified.

[0080] Four OIS magnets 142 are provided corresponding to the four AF magnets 141. Each of the four OIS magnets 142 is disposed adjacent to a corresponding AF magnet 141 in the Z direction (optical axis direction).

[0081] Each OIS magnet 142 is configured to have a substantially isosceles trapezoidal shape in a plan view, similar to the AF magnet 141. In other words, when placed in the magnet holder 12, the shape of the OIS magnet 142 is the same as that of the AF magnet 141 when viewed from the Z direction.

[0082] Here, the term "same shape" includes shapes that are completely identical in size, as well as shapes that have slight dimensional differences due to, for example, manufacturing errors. Furthermore, if there is a slight dimensional difference between AF magnet 141 and OIS magnet 142, one of AF magnet 141 and OIS magnet 142 may be positioned so that it protrudes from the other of AF magnet 141 and OIS magnet 142. Furthermore, if AF magnet 141 and OIS magnet 142 have completely identical shapes, AF magnet 141 and OIS magnet 142 may be positioned with a misalignment that does not affect the operation of lens drive device 1.

[0083] OIS magnet 142 has three single-pole magnets. Specifically, OIS magnet 142 has a first magnet 142A and two second magnets 142B and 142C.

[0084] The first magnet 142A is arranged so that its magnetic poles are aligned in a direction (U direction or V direction) along the XY plane (plane orthogonal to the optical axis) that is orthogonal to the Z direction. Specifically, the first magnet 142A is magnetized so that the inside of the lens driving device 1 is the north pole and the outside of the lens driving device 1 is the south pole. In other words, the first magnet 142A is arranged so that its magnetic poles are aligned in the same direction as the magnetic poles of the AF magnet 141.

[0085] In the explanation of Figure 8 etc., we will explain the OIS magnet 142 of the four OIS magnets 142 in a position where the inside of the lens driving device 1 is the + side of the U direction and the outside of the lens driving device 1 is the - side of the U direction.

[0086] The two second magnets 142B, 142C are arranged so as to sandwich the magnetic poles of the first magnet 142A in the direction along the plane orthogonal to the optical axis (the U direction in FIG. 8 and other figures). Of the two second magnets 142B, 142C, the second magnet 142B, which is located on the negative side of the first magnet 142A in the U direction, is magnetized so that its north pole is aligned followed by its south pole from the positive side in the Z direction. Of the two second magnets 142B, 142C, the second magnet 142C, which is located on the positive side of the U direction from the first magnet 142A, is magnetized so that its south pole is aligned followed by its north pole from the positive side in the Z direction.

[0087] In other words, the two second magnets 142B and 142C are arranged so that their magnetic poles are aligned in the Z direction (optical axis direction) and so that the orientations of the magnetic poles are opposite to each other. In other words, the two second magnets 142B and 142C are arranged so that their magnetic poles are aligned in a direction perpendicular to the direction in which the magnetic poles of the AF magnet 141 are aligned.

[0088] In this way, first magnet 142A and two second magnets 142B, 142C are arranged so that the magnetic pole orientation differs by 90 degrees from that of adjacent magnets in the U direction, thereby magnetizing OIS magnet 142 in a Halbach array. In other words, first magnet 142A and two second magnets 142B, 142C are arranged in accordance with the Halbach array so that the magnetic force is stronger on the side facing OIS coil 23 (the negative side in the Z direction) than on the opposite side (the positive side in the Z direction).

[0089] Furthermore, the second magnet 142B on the negative side in the U direction is located at a position corresponding to the south pole of the AF magnet 141. In other words, the first pole (north pole) of the second magnet 142B that faces the AF magnet 141 is located at a position corresponding to a pole (south pole) in the AF magnet 141 that has a different polarity from the first pole.

[0090] The second magnet 142C on the positive side in the U direction is located at a position corresponding to the north pole of the AF magnet 141. In other words, the second pole (south pole) of the second magnet 142C facing the AF magnet 141 is located at a position corresponding to a pole (north pole) in the AF magnet 141 that has a different polarity from the second pole.

[0091] By arranging the two second magnets 142B and 142C in this manner, each of the second magnets 142B and 142C is magnetically attracted to the AF magnet 141. As a result, the OIS magnet 142 is more easily fixed to the AF magnet 141.

[0092] As shown in FIGS. 9 and 10, the first magnet 142A and the two second magnets 142B, 142C face the first portion 231 and the second portion 232 of the OIS coil 23 in the Z direction.

[0093] First portion 231 is a portion corresponding to the outside of coil substrate 22 of OIS coil 23, which is configured in an annular shape, and is located in a range that overlaps with first magnet 142A and second magnet 142B on the negative side in the U direction when viewed from the Z direction. Second portion 232 is a portion corresponding to the inside of coil substrate 22 of OIS coil 23, which is configured in annular shape, and is located in a range that overlaps with first magnet 142A and second magnet 142B on the positive side in the U direction when viewed from the Z direction. In other words, OIS coil 23 is located in a range that overlaps with the projection plane of OIS magnet 142 in the Z direction.

[0094] Furthermore, the OIS magnet 142 is located on the negative side in the Z direction relative to the AF coil 13. In other words, the AF coil 13 is located within the range of the AF magnet 141 in the Z direction.

[0095] The cover portion 143 is a member that encloses the entire drive magnet 14, and is made of, for example, a non-magnetic metal plate (for example, copper). The cover portion 143 has a first portion 143A and a second portion 143B.

[0096] The first portion 143A is a portion disposed on the positive side in the Z direction of the drive magnet 14 (AF magnet 141). The second portion 143B is a portion extending from both sides of the first portion 143A in the U direction to the negative side in the Z direction. Note that while Figures 8A and 8B show a configuration in which the magnetic poles of the AF magnet 141 are aligned in the U direction, if the magnetic poles of the AF magnet 141 are aligned in the V direction, the second portion 143B would be a portion extending from both sides of the first portion 143A in the V direction to the negative side in the Z direction.

[0097] With this configuration, the cover portion 143 is configured so that the two second portions 143B can sandwich the entire drive magnet 14. As a result, the AF magnet 141 and the OIS magnet 142 can be easily fixed.

[0098] The effects of the present embodiment configured as above will now be described. Fig. 11 is a diagram for explaining the flow of magnetic flux in the drive magnet in a conventional example. Fig. 12 is a diagram for explaining the flow of magnetic flux in the drive magnet in this embodiment.

[0099] For example, as in Patent Document 1, when the drive magnet is configured to serve as both an AF magnet and an OIS magnet, one of the AF coil and the OIS coil can be arranged to face the drive magnet in the direction in which the magnetic poles are aligned. Since the magnet basically has a magnetic flux flowing in the direction in which the magnetic poles are aligned as a magnetic pole pair of N and S poles, a sufficient amount of magnetic flux flows in one of the coils, making it possible to drive the drive unit corresponding to that coil with sufficient thrust.

[0100] However, the other of the AF coil and the OIS coil cannot face the drive magnet in the direction in which the magnetic poles are aligned. Therefore, magnetic flux flows in the other coil, circling from the north pole to the south pole located on the opposite side. This means that the amount of magnetic flux flowing in a direction other than the direction in which the magnetic poles are aligned increases in the other coil. In other words, the amount of magnetic flux flowing in a direction other than the direction in which the magnet faces increases in the other coil. This magnetic flux is difficult to use in the operation of the drive unit.

[0101] 11 , in a configuration in which the drive magnet 14 is arranged so that its magnetic poles are aligned in a direction facing the AF coil 13, a sufficient amount of magnetic flux flows from the drive magnet 14 to the AF coil 13 (see arrow B1). However, the OIS coil 23 is arranged in a direction substantially perpendicular to the direction in which the magnetic poles of the drive magnet 14 are aligned. Therefore, magnetic flux (see arrow B2) flows in the OIS coil 23, circling from the north pole of the drive magnet 14 toward the south pole. As described above, the magnetic flux of arrow B2 is difficult to use for operating the OIS drive unit.

[0102] In other words, in a configuration in which the drive magnet serves both as an AF magnet and an OIS magnet, it may be difficult to improve the thrust for either the AF drive or the OIS drive.

[0103] 12, drive magnet 14 has AF magnet 141 and OIS magnet 142. OIS magnet 142 has a magnet whose magnetic poles are aligned in a direction perpendicular to the direction in which the magnetic poles of AF magnet 141 are aligned.

[0104] This allows the drive magnet 14 to be positioned so that a sufficient amount of magnetic flux (see arrows B3 and B4) flows from each of the AF magnet 141 and the OIS magnet 142 to both the AF coil 13 and the OIS coil 23.

[0105] As a result, a sufficient amount of magnetic flux can be passed through both the AF coil 13 and the OIS coil 23, and the thrust for both the AF drive and the OIS drive can be improved.

[0106] Furthermore, in the magnet holder 12 that houses the drive magnet 14, the OIS magnet 142 is disposed adjacent to the AF magnet 141, so that the overall configuration can be made compact.

[0107] Furthermore, first magnet 142A and two second magnets 142B, 142C are arranged in a Halbach array so that the magnetic force is stronger on the side facing OIS coil 23 than on the opposite side. As a result, the amount of magnetic flux flowing through OIS coil 23 can be further increased, thereby further improving the thrust force produced by OIS drive. Furthermore, while the magnetic force can be strengthened even in a configuration without a first magnet (a configuration with only a second magnet), the magnetic force on the OIS coil 23 side can be further increased by providing first magnet 142A. As a result, the thrust force produced by OIS drive can be significantly improved.

[0108] Furthermore, since OIS coil 23 is positioned in a range that overlaps with the Z-direction projection plane of OIS magnet 142 , magnetic flux flowing from OIS magnet 142 can be reliably passed through OIS coil 23 .

[0109] Incidentally, when the AF magnet and the OIS magnet have different shapes, it is necessary to adjust the magnet holder to the shape of the larger of the AF magnet and the OIS magnet.

[0110] In contrast, in the present embodiment, the shape of OIS magnet 142 is the same as that of AF magnet 141 when viewed from the Z direction when placed in magnet holder 12. As a result, there is no need to match magnet holder 12 to the shape of either AF magnet 141 or OIS magnet 142, so the shape of magnet holder 12 can be simplified, and the overall size can be made more compact. Also, it becomes easier to arrange AF magnet 141 and OIS magnet 142 within magnet holder 12.

[0111] Furthermore, since the cover portion 143 surrounds the AF magnet 141 and the OIS magnet 142, the AF magnet 141 and the OIS magnet 142 can be easily fixed.

[0112] Furthermore, because OIS magnet 142 is made up of three single-pole magnets, the three single-pole magnets can be sandwiched by cover portion 143. First magnet 142A is sandwiched between second magnets 142B and 142C, but the magnetic pole of first magnet 142A is adjacent to both the north and south poles of second magnets 142B and 142C. As a result, there is a magnetic repulsion between the magnetic pole of first magnet 142A and the magnetic pole of the same polarity, which may make it difficult to determine the arrangement of OIS magnet 142.

[0113] In contrast, in this embodiment, the three monopole magnets are sandwiched between cover portion 143, so that the arrangement of OIS magnet 142 can be stabilized.

[0114] In the above embodiment, the OIS magnet has the same shape as the AF magnet when viewed in the optical axis direction, but the present invention is not limited to this, and the OIS magnet may have a different shape from the AF magnet.

[0115] Furthermore, in the above embodiment, the number of drive magnets was four, but the present invention is not limited to this, and the number of drive magnets may be any number as long as it is a number appropriate for the configuration of the drive device.

[0116] Furthermore, in the above embodiment, the OIS driving unit drives the lens holder, but the present invention is not limited to this. For example, as shown in FIG. 14, the OIS driving unit may drive the image sensor.

[0117] FIG. 13 shows a simplified cross-sectional view of the lens driving device 1 taken along a plane perpendicular to the U direction.

[0118] The image stabilization method in this configuration is a so-called sensor shift method in which the image sensor is swung. This configuration differs from the configurations shown in Figures 2 to 6 in that the image sensor board 41 and the image sensor 42 are provided on the positive side of the base 21 in the Z direction.

[0119] The image sensor substrate 41 is disposed on the negative side in the Z direction of the coil substrate 22 on which the OIS coil 23 is disposed. An opening is formed in the portion of the image sensor substrate 41 that corresponds to the lens housing portion 111, and the image sensor 42 is disposed in the opening. In this configuration, the coil substrate 22 corresponds to the "image sensor holding portion" of the present invention.

[0120] The image sensor substrate 41 constitutes an OIS movable part that can swing in a plane perpendicular to the optical axis direction. The configuration of the OIS movable part (the configuration that moves the image sensor) can adopt a known sensor shift type configuration, and therefore a description thereof will be omitted.

[0121] Even with this configuration, it is possible to improve the thrust of the drive operations of both the AF drive unit and the OIS drive unit.

[0122] Furthermore, in the above embodiment, the OIS magnet has the same shape as the AF magnet when viewed in the optical axis direction, but the present invention is not limited to this, and the OIS magnet does not have to have the same shape as the AF magnet. However, it is preferable that the OIS magnet is positioned so that it is not located closer to the optical axis (lens holder side) than the AF magnet, so as not to affect the magnetic flux flowing from the AF magnet to the AF coil.

[0123] Furthermore, for example, in the above embodiment, a smartphone, which is a camera-equipped mobile terminal, was described as an example of a camera-equipped device equipped with a camera module A. However, the present invention can be applied to camera-equipped devices having a camera module and an image processing unit that processes image information obtained by the camera module. Camera-equipped devices include information devices and transportation equipment. Information devices include, for example, camera-equipped mobile phones, laptop computers, tablet terminals, portable game consoles, web cameras, drones, and camera-equipped in-vehicle devices (e.g., backup monitor devices and drive recorder devices). Transportation equipment includes, for example, automobiles and drones.

[0124] 14A and 14B are diagrams showing an automobile V as a camera-mounted device equipped with an in-vehicle camera module VC (Vehicle Camera). FIG. 14A is a front view of the automobile V, and FIG. 14B is a rear perspective view of the automobile V. The automobile V is equipped with the camera module described in the embodiment as the in-vehicle camera module VC. As shown in FIGS. 14A and 14B , the in-vehicle camera module VC is attached, for example, to the windshield facing forward or to the rear gate facing backward. This in-vehicle camera module VC is used for backup monitoring, drive recorders, collision avoidance control, autonomous driving control, etc.

[0125] Furthermore, the above-described embodiments are merely examples of specific embodiments of the present invention, and the technical scope of the present invention should not be interpreted as being limited by these embodiments. In other words, the present invention can be embodied in various forms without departing from the gist or main features of the present invention. For example, the shapes, sizes, numbers, and materials of the components described in the above-described embodiments are merely examples, and can be modified as appropriate.

[0126] The disclosures of the specification, drawings and abstract contained in Japanese Patent Application No. 2024-053623, filed on March 28, 2024, are incorporated herein by reference in their entirety.

[0127] The drive device according to the present invention is useful as a drive device, camera module, and camera-mounted device that can improve the thrust of the drive operation of both the AF drive unit and the OIS drive unit.

[0128] REFERENCE SIGNS LIST 1 Lens drive device, 2 Lens unit, 11 Lens holder, 12 Magnet holder, 13 AF coil, 14 Drive magnet, 15 Upper elastic support member, 16 Lower elastic support member, 21 Base, 22 Coil substrate, 23 OIS coil, 24 Suspension wire, 141 AF magnet, 142 OIS magnet, 142A First magnet, 142B Second magnet, 142C Second magnet, 143 Cover unit, 143A First unit, 143B Second unit, D1 OIS drive unit, F1 OIS fixed unit, M1 OIS movable unit, S1 OIS support unit, M Smartphone, A Camera module

Claims

1. A lens holder for holding a lens, a magnet holder surrounding at least a portion of the lens holder and accommodating a magnet portion, a drive portion having the magnet portion and a coil portion, and an image sensor holding portion for holding an image sensor facing the lens in the optical axis direction, wherein the magnet portion has an autofocus magnet for driving the lens holder in the optical axis direction, and a shake correction magnet for driving the lens holder or the image sensor holding portion in a direction orthogonal to the optical axis direction, the coil portion has an autofocus coil facing the autofocus magnet, and a shake correction coil facing the shake correction magnet, the shake correction magnet has a first magnet and a second magnet arranged adjacent to the autofocus magnet in the optical axis direction, the first magnet is arranged so that its magnetic poles are aligned in the same direction as the magnetic poles of the autofocus magnet, and the second magnet is arranged so that its magnetic poles are aligned in a direction perpendicular to the direction in which the magnetic poles of the autofocus magnet are aligned, At least two of the driving devices are provided so as to sandwich the magnetic poles of the first magnet.

2. The drive device according to claim 1, wherein the first magnet and the second magnet are arranged in a Halbach array so that the magnetic force on the side facing the shake correction coil is stronger than on the opposite side.

3. The drive device according to claim 1, wherein the autofocus magnet, the first magnet, and the second magnet are unipolar magnets.

4. The drive device according to claim 3, wherein the two second magnets are arranged so that their magnetic poles are oriented in opposite directions.

5. The drive device according to claim 1, further comprising a cover portion that encloses the autofocus magnet and the shake correction magnet.

6. The drive device according to claim 1, wherein the shape of the shake correction magnet, when placed in the magnet holder, is the same as the shape of the autofocus magnet when viewed in the optical axis direction.

7. The drive device according to claim 1, wherein four of the autofocus magnets are arranged to surround the autofocus coil on all sides, and four of the shake correction magnets are provided corresponding to the four autofocus magnets, respectively.

8. The drive device according to claim 1, wherein the autofocusing coil faces the autofocusing magnet in a direction along the alignment of the magnetic poles of the autofocusing magnet, and the shake correction coil faces the shake correction magnet in a direction along the alignment of the magnetic poles of the second magnet.

9. A camera module comprising: the driving device according to claim 1; an element section including the lens; and an imaging section including the imaging element for capturing an image of a subject formed by the element section.

10. A camera-equipped device that is an information device or a transportation device, comprising: a camera module according to claim 9; and an imaging control unit that processes image information obtained by the camera module.

Images