Motor, blade drive device, camera module, and camera-equipped device

Abstract

To provide a motor which can be reduced in size and height, a blade drive device, a camera module, and a camera-equipped device.SOLUTION: A motor is provided, comprising a fixed body having a coil, a movable body having a magnet arranged opposite the coil, a fluid support unit for movably supporting the movable body relative to the fixed body, and limiting parts for limiting the distance between the magnet and the coil.SELECTED DRAWING: Figure 12

Description

[Technical Field]

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

[0002] Generally, camera-equipped devices such as smartphones and drones are equipped with a small camera module (optical device). Drones are unmanned aerial vehicles that can be flown by remote control or automatic control, and some are called multicopters.

[0003] The camera module uses an optical element driving device that drives optical elements such as lenses. The optical element driving device has, for example, an autofocus function (hereinafter referred to as the "AF function") that moves an optical element (e.g., a lens) in the optical axis direction to automatically focus when photographing a subject, and an image stabilization function (hereinafter referred to as the "OIS function") that optically corrects shake (vibration) that occurs during photography to reduce image distortion.

[0004] In recent years, camera modules have been developed that include an optical element driving device as well as a blade driving device that can adjust the amount of light incident on an optical element (see, for example, Patent Document 1). The blade driving device includes, for example, a fixed body, a movable body (rotating body) that can rotate relative to the fixed body, diaphragm blades that move to open and close the aperture in conjunction with the rotation of the movable body, and a driving unit that drives the movable body. The driving unit is, for example, composed of a motor that has a coil arranged in the fixed body and a magnet arranged in the movable body. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-122915 Summary of the Invention [Problem to be solved by the invention]

[0006] As demands for further miniaturization of camera modules continue, it is becoming increasingly important to reduce the size and height of the blade drive devices mounted on camera modules, and in turn the motors of the blade drive devices.

[0007] An object of the present invention is to provide a motor, a blade driving device, a camera module, and a camera-mounted device that can be made smaller and thinner. [Means for solving the problem]

[0008] The motor according to the present invention comprises: a fixed body having a coil; a movable body having a magnet arranged opposite to the coil; a fluid support portion that supports the movable body movably relative to the fixed body; and a restricting portion that restricts the distance between the magnet and the coil.

[0009] The blade drive device according to the present invention comprises: A blade drive device capable of adjusting the amount of light incident on an optical element through an opening, The above motor and and aperture blades that open and close the aperture in conjunction with the rotation of the movable body.

[0010] The camera module according to the present invention comprises: The blade drive device is provided.

[0011] The camera-equipped device according to the present invention comprises: A camera-equipped device that is an information device or a transportation device, The camera module is provided. [Effects of the Invention]

[0012] The motor, blade drive device, camera module, and camera-mounted device according to the present invention can be made smaller and thinner. [Brief explanation of the drawings]

[0013] [Figure 1] 1A and 1B are diagrams showing a smartphone equipped with a camera module according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view of the appearance of the camera module. [Figure 3] FIG. 3 is an exploded perspective view of the camera module. [Figure 4] FIG. 4 is an exploded perspective view of the blade drive device. [Figure 5] FIG. 5 is a partial cross-sectional view of the blade drive device. [Figure 6] FIG. 6 is a plan view of the blade drive device. [Figure 7] FIG. 7 is an exploded perspective view of the drive motor. [Figure 8] FIG. 8 is a plan view showing a specific example of a coil on a coil substrate. [Figure 9] FIG. 9 is a diagram showing the configuration of the magnet. [Figure 10] 10A and 10B are diagrams that schematically show the magnetic flux of a magnet that intersects with the coil when the motor is in operation. [Figure 11] 11A and 11B are diagrams schematically showing the magnetic flux of a magnet that intersects with the detection unit. [Figure 12] FIG. 12 is a schematic diagram showing an example of a restricting portion. [Figure 13] FIG. 13 is a schematic diagram showing another example of the restricting portion. [Figure 14] 14A and 14B are diagrams showing an automobile as a camera-mounted device equipped with an in-vehicle camera module. DETAILED DESCRIPTION OF THE INVENTION

[0014] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0015] <Smartphone> 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.

[0016] The smartphone M has a dual camera system consisting of two rear cameras OC1 and OC2. In this embodiment, the camera module A is applied to the rear cameras OC1 and OC2.

[0017] <Camera module> Fig. 2 is a perspective view of the appearance of the camera module A. Fig. 3 is an exploded perspective view of the camera module A. In this embodiment, an orthogonal coordinate system (X, Y, Z) is used for explanation. The same orthogonal coordinate system (X, Y, Z) is also used in the drawings described later.

[0018] For example, when actually taking a photograph on a smartphone M, the camera module A is mounted so that the X-axis direction is the up-down direction (or left-right direction), the Y-axis direction is the left-right direction (or up-down direction), and the Z-axis direction is the front-back direction. That is, the Z-axis direction is the optical axis direction, and the upper side (+Z side) in the figure is the light-receiving side in the optical axis direction, and the lower side (-Z side) is the image-forming side in the optical axis direction. Furthermore, the X-axis and Y-axis directions orthogonal to the Z axis are referred to as "directions orthogonal to the optical axis," and the XY plane is referred to as "plane orthogonal to the optical axis." Note that the optical axis direction may also be referred to as the optical path direction or the focal direction (the direction in which the focus is adjusted) depending on the type of optical element.

[0019] Camera module A is equipped with an AF function that allows it to automatically focus when photographing a subject. Camera module A also has an OIS function that optically corrects shake (vibration) that occurs during photography, allowing you to take blur-free images.

[0020] As shown in FIGS. 2 and 3, the camera module A includes an optical element driving device 1, a lens unit 2, an imaging unit 3, a blade driving device 4, and the like.

[0021] The optical element driving device 1 of this embodiment is designed with consideration for being mounted on the above-mentioned camera module A, etc., and is configured so that its length in the Z-axis direction is shorter than its lengths in the X-axis direction and Y-axis direction, i.e., its height along the Z-axis direction is reduced.

[0022] The optical element driving device 1 is configured to be able to move the lens unit 2, for example, in the optical axis direction and in a direction perpendicular to the optical axis. The optical element driving device 1 realizes an AF function and / or a zoom function by moving the lens unit 2 in the optical axis direction. The optical element driving device 1 also realizes an OIS function by moving the lens unit 2 in the direction perpendicular to the optical axis. A known configuration can be applied to the optical element driving device 1, so a detailed description will be omitted.

[0023] The lens unit 2 has a lens and a lens barrel that holds the lens. The lens unit 2 is housed in the optical element driving device 1 and fixed therein.

[0024] The imaging unit 3 captures the subject image formed by the lens unit 2. The imaging unit 3 is disposed on the imaging side in the Z-axis direction of the optical element driving device 1. The imaging unit 3 includes, for example, an image sensor board 301, an imaging element 302 mounted on the image sensor board 301, and a module control unit 303.

[0025] The image sensor substrate 301 is, for example, a flexible printed circuit (FPC) board, and is configured to be able to transmit an imaging signal obtained by the imaging element 302 to a control device (not shown) of the smartphone M. The control device of the smartphone M includes an image processing unit (not shown) that processes the received imaging signal.

[0026] The image sensor 302 is configured by, for example, a charge-coupled device (CCD) image sensor, a complementary metal oxide semiconductor (CMOS) image sensor, or the like, and captures the subject image formed by the lens unit 2 .

[0027] The module control unit 303 is configured by, for example, a control IC, and controls the driving of the optical element driving device 1 and the blade driving device 4. The optical element driving device 1 is mounted on the image sensor substrate 301 and is mechanically and electrically connected thereto. The module control unit 303 may be provided on the image sensor substrate 301, or may be provided in a camera-equipped device (in this embodiment, a smartphone M) on which the camera module A is mounted.

[0028] The blade driving device 4 adjusts the amount of light incident on the lens unit 2. The blade driving device 4 is fixed to a movable part of the lens unit 2 or the optical element driving device 1, and is movable in the optical axis direction together with the movable parts of the lens unit 2 and the optical element driving device 1. The blade driving device 4 is supplied with driving power and control signals (clock signal and data signal) via the optical element driving device 1.

[0029] Fig. 4 is an exploded perspective view of the blade drive device 4. Fig. 5 is a cross-sectional view of the blade drive device 4. Fig. 6 is a plan view of the blade drive device 4 as seen from the light-receiving side in the optical axis direction. In Fig. 6, the pressing cover 40 is omitted. Fig. 7 is an exploded perspective view of the drive motor 10.

[0030] As shown in FIGS. 4 to 6, the blade drive device 4 includes a drive motor 10, an aperture member 20, an aperture blade 30, a presser cover 40, and the like.

[0031] The drive motor 10 has a stator 11, a rotor 12, and a fluid support portion 13 (see FIG. 7). In the drive motor 10, the rotor 12, which is a movable body, is rotatable relative to the stator 11, which is a fixed body, via the fluid support portion 13. The drive motor 10 is a so-called axial gap type rotary motor in which the stator 11 and the rotor 12 face each other in the direction of the rotation axis. The direction of the rotation axis of the drive motor 10 coincides with the optical axis direction of the blade drive device 4.

[0032] The stator 11 has a coil 111, a base 112, a coil substrate 113, a yoke 114, and a stator cover 115. The base 112 and the stator cover 115 form a housing for the drive motor 10. The rotor 12 has a magnet 121 and a rotor frame 122. The stator 11 supports the rotor 12 via a fluid support portion 13 so that the rotor 12 can rotate in the circumferential direction around the optical axis (around the rotation axis).

[0033] The base 112 is a low-profile, bottomed cylindrical member having a bottom surface 112a and a peripheral surface 112b. The base 112 has an opening 112c in the center of the bottom surface 112a. The base 112 has an engagement pin 112d and a cover fixing portion 112e on the peripheral edge of the opening 112c. The engagement pin 112d is formed on a bulge 112g formed on the peripheral edge of the opening 112c, protruding toward the light-receiving side in the optical axis direction. The cover fixing portion 112e is formed on the bulge 112g so as to be recessed toward the imaging side in the optical axis direction. The base 112 also has notches 112f in two locations on the peripheral surface 112b.

[0034] The stator cover 115 is a ring-shaped member having an opening 115a in the center. The outer shape of the stator cover 115 in a plan view is the same as the outer shape of the bottom surface 112a of the base 112. The stator cover 115 has a plurality of guide holes 115b. In this embodiment, six guide holes 115b are provided. The guide holes 115b are formed in an arc shape so as to extend along the circumferential direction. The stator cover 115 also has a fixing piece 115c on the periphery of the opening 115a. The fixing piece 115c is formed on the periphery of the opening 115a so as to hang down toward the imaging side in the optical axis direction.

[0035] The stator cover 115 is disposed and fixed so as to cover the upper surface of the base 112. For example, the stator cover 115 is fixed to the base 112 by inserting the fixing pieces 115c of the stator cover 115 into the cover fixing portions 112e of the base 112 and filling the cover fixing portions 112e with adhesive (see FIG. 5). The stator cover 115 functions as a damming member that prevents the fluid support portion 13 from flowing out.

[0036] The coil substrate 113 has, for example, a ring-shaped substrate main body 113a and terminal portions 113b provided continuously at two locations on the substrate main body 113a. The shape of the substrate main body 113a matches the shape of the bottom surface 112a of the base 112. The coil substrate 113 is placed on and fixed to the bottom surface 112a of the base 112. The terminal portions 113b are drawn outward in the radial direction from cutout portions 112f of the base 112.

[0037] The coil substrate 113 is a flexible printed circuit board on which the coil 111 is mounted. The coil substrate 113 is formed, for example, by laminating a thin insulating layer such as a resin film and a metal layer such as copper foil. The metal layer forms circuit wiring (not shown) such as signal lines and power lines, and the coil 111. A portion of the metal layer disposed in the terminal portion 113b is exposed and is electrically and mechanically connected to the electrical system of the optical element driving device 1.

[0038] Furthermore, a detection unit 116 (see FIG. 8) that detects the rotational position of the rotor 12 (magnet 121) is mounted on the coil substrate 113. The detection unit 116 is configured, for example, with a Hall element that can magnetically detect the rotational position of the rotor 12. The detection unit 116 is disposed, for example, on the rear surface (the surface on the imaging side in the optical axis direction) of the coil substrate 113, at a position corresponding to the hollow portion of one of the coils 111.

[0039] The coil 111 is, for example, a planar coil in which a conductor is wound in a spiral shape (see FIG. 8). The coil 111 has a rectangular or elliptical shape. The coil 111 has circumferentially opposed portions 111a opposed in the circumferential direction and radially opposed portions 111b opposed in the radial direction. A plurality of the coils 111 are arranged along the circumferential direction on the coil substrate 113. In this embodiment, eight coils 111 are formed on the coil substrate 113.

[0040] The yoke 114 is made of a magnetic material. The yoke 114 is disposed so as to face the magnet 121 in the optical axis direction (rotation axis direction) and generates a magnetic attraction force on the magnet 121. The yoke 114 is fixed, for example, by being fitted into a recessed groove (reference numeral omitted) provided in the bottom surface 112a of the base 112. The coil substrate 113 (coil 111) is sandwiched between the yoke 114 and the magnet 121. By disposing the yoke 114, the magnetic flux radiated from the magnet 121 can efficiently intersect with the coil 111.

[0041] Magnet 121 is a ring-shaped multi-pole magnet in which south poles and north poles are arranged alternately in the circumferential direction (see FIG. 9). In FIG. 9, the arrangement of coils 111 relative to magnet 121 is indicated by dashed lines. Magnet 121 may be a single-sided multi-pole magnet in which one side is magnetized, or a double-sided multi-pole magnet in which both sides are magnetized.

[0042] The shape of the magnet 121 is the same as that of the substrate main body 113a of the coil substrate 113. In the drive motor 10, the magnet 121 and the coil 111 are arranged to face each other in the optical axis direction (rotation axis direction).

[0043] The magnet 121 has a first magnetic pole portion 21 having a first length in the circumferential direction, and a second magnetic pole portion 22 having a second length in the circumferential direction that is shorter than the first length. Hereinafter, of the first magnetic pole portion 21 and the second magnetic pole portion 22, the magnetic pole portions magnetized to the N pole will be referred to as the "first magnetic pole portion 21N" and the "second magnetic pole portion 22N," and the magnetic pole portions magnetized to the S pole will be referred to as the "first magnetic pole portion 21S" and the "second magnetic pole portion 22S."

[0044] The first magnetic pole portion 21N has a second magnetic pole portion 22S of opposite polarity arranged on one circumferential side, and a first magnetic pole portion 21S of opposite polarity arranged on the other circumferential side.The first magnetic pole portion 21S has a second magnetic pole portion 22N of opposite polarity arranged on one circumferential side, and a first magnetic pole portion 21N of opposite polarity arranged on the other circumferential side.

[0045] The second magnetic pole portion 22N has first magnetic pole portions 21S with opposite polarities arranged on both sides in the circumferential direction. The second magnetic pole portion 22S has first magnetic pole portions 21N with opposite polarities arranged on both sides in the circumferential direction.

[0046] Furthermore, the magnet 121 has an unmagnetized neutral portion 23 between two adjacent first magnetic pole portions 21N, 21S. In this embodiment, the neutral portions 23 are arranged at two locations facing each other in the radial direction.

[0047] The magnet 121 preferably has a distinguishing means for distinguishing between the ranges of the first magnetic pole portion 21 and the second magnetic pole portion 22. The distinguishing means may be capable of distinguishing between the ranges of the first magnetic pole portion 21 and the second magnetic pole portion 22 that are adjacent in the circumferential direction and / or the ranges of the first magnetic pole portion 21 and the second magnetic pole portion 22 that overlap in the optical axis direction.

[0048] The distinguishing means can distinguish the ranges of the first magnetic pole portion 21 and the second magnetic pole portion 22 by coloring, for example. Alternatively, the distinguishing means can distinguish the ranges of the first magnetic pole portion 21 and the second magnetic pole portion 22 by a groove provided at the boundary between the first magnetic pole portion 21 and the second magnetic pole portion 22. By providing the distinguishing means on the magnet 121, the ranges of the first magnetic pole portion 21 and the second magnetic pole portion 22 can be clearly grasped, and the circumferential positions of the coil 111 and the magnet 121 can be appropriately adjusted.

[0049] The rotor frame 122 is a holder that holds the magnet 121. The rotor frame 122 has a ring shape, similar to the magnet 121. The magnet 121 is fitted and fixed in, for example, a magnet accommodating groove (not shown) provided on the lower surface of the rotor frame 122.

[0050] The rotor frame 122 has an engagement pin 122a. The engagement pin 122a is formed to protrude in the optical axis direction toward the light receiving side. The engagement pin 122a is provided to correspond to the guide hole 115b of the stator cover 115.

[0051] The rotor 12 is disposed on the light-receiving side in the optical axis direction of the coil substrate 113 via the fluid support portion 13. A stator cover 115 is disposed on the light-receiving side in the optical axis direction of the rotor 12 and fixed to the base 112, thereby integrating the rotor 12 and the stator 11.

[0052] The rotor 12 is held in a state in which it is supported by the fluid support part 13, as a result of the magnet 121 being magnetically attracted to the yoke 114 fixed to the base 112. In other words, the magnet 121 is supported by the fluid support part 13 so as to be rotatable relative to the coil 111.

[0053] The rotor 12 is disposed so that the magnetic flux of the magnet 121 intersects with the two circumferentially opposing portions 111a of the coil 111 in mutually opposite directions. At this time, the detection portion 116 overlaps with the neutral portion 23 of the magnet 121 in the optical axis direction. When the rotor 12 is assembled to the stator 11, the engagement pin 122a engages with the guide hole 115b.

[0054] Fluid support portion 13 supports rotor 12 rotatably relative to stator 11. Fluid support portion 13 is applied, for example, to the surface of coil substrate 113 on the light-receiving side in the optical axis direction (the surface facing magnet 121). Contact between rotor 12 and fluid support portion 13 is contact between a fixed object and a fluid (liquid), so frictional resistance is extremely small, and wear of rotor 12 that may occur during motor operation can be suppressed.

[0055] The fluid support 13 is preferably made of a magnetic fluid. A magnetic fluid is a liquid that is magnetized in a magnetic field, and is, for example, a magnetic colloid solution containing ferromagnetic ultrafine particles such as magnetite and composite ferrite, a surfactant, and a base liquid such as water or oil. The size of the ferromagnetic ultrafine particles is usually on the nanometer order.

[0056] When fluid support portion 13 is made of a magnetic fluid, the magnetic fluid is held along the magnetic field lines of magnet 121, forming a magnetic gap. Coil 111 of stator 11 and magnet 121 of rotor 12 are held in a spaced-apart state by the magnetic gap, which improves strength against loads from the optical axis direction compared to when coil 111 and magnet 121 are held in a spaced-apart state by an air gap.

[0057] The diaphragm blades 30 are made up of, for example, six blade members 31. The diaphragm blades 30 are attached so as to straddle the stator 11 and the rotor 12 via the aperture member 20. The aperture member 20 defines the opening of the blade drive device 4 when the diaphragm blades 30 are in a fully open state. The diaphragm blades 30 move in conjunction with the rotation of the rotor 12 to open and close the opening of the blade drive device 4.

[0058] Specifically, each blade member 31 has an engagement hole 31a and a cam hole 31b. The engagement hole 31a is fitted onto an engagement pin 122a of the rotor frame 122. The cam hole 31b is engaged with an engagement pin 112d of the base 112.

[0059] The retaining cover 40 is disposed on the light receiving side of the diaphragm blade 30 in the optical axis direction, and prevents the diaphragm blade 30 from falling off.

[0060] Power and control signals (clock signals and data signals) are supplied to the blade driving device 4 via the electrical system of the optical element driving device 1. The driving motor 10 is driven based on the supplied power and control signals, and the rotor 12 rotates relative to the stator 11.

[0061] Specifically, when current is applied to coil 111, a Lorentz force is generated in coil 111 (Fleming's left-hand rule) due to the interaction between the magnetic field of magnet 121 and the current flowing through coil 111. The direction of the Lorentz force is perpendicular to the direction of the magnetic field (Z-axis direction) and the direction of the current in circumferentially opposing portion 111a of coil 111.

[0062] In the two circumferentially opposing portions 111a, the current flows in opposite directions and the intersecting magnetic fluxes also flow in opposite directions, so Lorentz forces are generated in the same direction in the circumferential direction. In the two radially opposing portions 111b, the current flows in opposite directions and the intersecting magnetic fluxes are the same, so Lorentz forces are generated in opposite directions in the radial direction and cancel each other out. Current flow to each coil 111 is controlled so that Lorentz forces are generated in the same circumferential direction in all coils 111. Because the coils 111 are fixed, a reaction force acts on the magnets 121. This reaction force becomes the driving force of the drive motor 10, causing the rotor 12, which has the magnets 121, to rotate.

[0063] As the rotor 12 rotates, the engagement pin 122a of the rotor frame 122 moves in the circumferential direction. The movement of the blade member 31 is restricted by the cam hole 31b and the engagement pin 112d of the base 112, so the blade member 31 rotates around the engagement pin 122a of the rotor frame 122. This opens and closes the opening of the blade drive device 4, and the amount of light incident on the lens unit 2 is adjusted.

[0064] 10A, during operation of the drive motor 10, the magnetic flux directed from the first magnetic pole portion 21N of the magnet 121 to the adjacent first magnetic pole portion 21S mainly intersects with the circumferentially opposing portion 111a of the coil 111 in mutually opposite directions. The generation of magnetic flux formed by the first magnetic pole portion 21 and the second magnetic pole portion 22 can increase the magnetic flux directed from the first magnetic pole portion 21N of the magnet 121 to the adjacent first magnetic pole portion 21S.

[0065] When the N-pole and S-pole magnetic pole portions of the magnet 121 are all formed to be the same size (see FIG. 10B), magnetic flux is likely to be generated from the first magnetic pole portion 21N toward the first magnetic pole portion 21S facing the upper surface. In contrast, when the second magnetic pole portion 22 is provided, the magnetic flux from the first magnetic pole portion 21N of the magnet 121 toward the adjacent first magnetic pole portion 21S is likely to increase (see FIG. 10A). Note that the magnetic flux generated by the first magnetic pole portion 21 and the second magnetic pole portion 22 is generated mainly outside the operating range and does not interfere with the operation of the drive motor 10.

[0066] Furthermore, in the initial state in which the drive motor 10 is not operating, the neutral portion 23 of the magnet 121 and the detection portion 116 face each other in the optical axis direction. By providing the neutral portion 23 on the magnet 121, the magnetic flux that intersects with the detection portion 116 becomes nearly flat (see FIG. 11A). Therefore, the change in the detection value of the detection portion 116 that accompanies the rotation of the rotor 12 becomes gradual, and the rotational position of the rotor 12 (magnet 121) can be more easily detected than when the neutral portion 23 is not provided on the magnet 121 (see FIG. 11B).

[0067] Furthermore, the drive motor 10 is equipped with a regulating unit 14 that regulates the distance between the magnet 121 and the coil 111. The regulating unit 14 is, for example, a rolling element (see FIG. 12). The rolling element is made of, for example, fine particles of glass or ceramic, and is dispersed in the fluid support unit 13. The rolling element has enough rigidity to resist the magnetic attractive force between the magnet 121 and the yoke 114. The outer diameter of the rolling element is equal to or smaller than the thickness of the magnetic gap formed by the magnetic fluid (thickness when the magnetic attractive force is not taken into consideration).

[0068] The magnetic gap created by the fluid support portion 13 is crushed when the magnet 121 is attracted to the yoke 114, but a certain separation distance is ensured by the restricting portion 14. Therefore, the stability of the operation of the drive motor 10 is improved.

[0069] The restricting portion 14 of the drive motor 10 may be formed integrally with a component of the stator 11 or rotor 12. For example, as shown in FIG. 13, when the magnet 121 is supported by the base 112, a part of the base 112 (the side wall of the base 112 in FIG. 13) functions as the restricting portion 14. Also, a protruding piece that protrudes in the optical axis direction may be provided on a part of the rotor frame 122, and this protruding piece may be brought into contact with the stator 11 to function as the restricting portion 14.

[0070] As described above, this embodiment discloses a drive motor 10 that includes the following features either singly or in appropriate combination.

[0071] That is, the drive motor 10 (motor) comprises a stator 11 (fixed body) having a coil 111, a rotor 12 (movable body) having a magnet 121 arranged opposite the coil 111, a fluid support part 13 that supports the rotor 12 movably relative to the stator 11, and a regulating part 14 that regulates the distance between the magnet 121 and the coil 111.

[0072] Specifically, the fluid support 13 is made of a magnetic fluid, and forms a magnetic gap between the magnet 121 and the coil 111 .

[0073] By using the fluid support part 13, which is not rigid, as a support part that supports the rotor 12 relative to the stator 11, it is possible to reduce the size and height of the drive motor 10. Furthermore, the restricting part 14 ensures a constant distance between the magnet 121 and the coil 111, thereby improving the operational stability of the drive motor 10. Furthermore, by providing the restricting part 14, the impact resistance of the drive motor 10 is improved.

[0074] In the drive motor 10, the restricting portion 14 is a rolling element, which makes it possible to ensure a separation distance between the magnet 121 and the coil 111 without interfering with the operation of the rotor 12 (movable element).

[0075] In the drive motor 10, the restriction portion 14 may be formed integrally with a component (for example, the base 112) of the stator 11 (fixed body) or the rotor 12 (movable body). This makes it possible to ensure the separation distance between the magnet 121 and the coil 111 by utilizing the component of the drive motor 10.

[0076] In the drive motor 10, the stator 11 (fixed body) has a damming member (for example, a stator cover 115) that prevents the fluid support portion 13 from leaking out. This prevents the fluid support portion 13 from leaking out, improving the reliability of the drive motor 10.

[0077] In the drive motor 10, the magnet 121 is a ring-shaped multi-pole magnet in which south poles and north poles are arranged alternately in the circumferential direction, the coil 111 is a planar coil having two circumferentially opposing portions 111a that face each other in the circumferential direction, and is arranged so that the magnetic fluxes of the magnet 121 cross each other in opposite directions at the circumferentially opposing portions 111a, and the fluid support part 13 supports the magnet 121 rotatably relative to the coil 111. This makes it possible to use the drive motor for the blade drive device 4, and to make the blade drive device 4 smaller and thinner.

[0078] Furthermore, this embodiment discloses a blade drive device 4 that includes the following features either alone or in appropriate combination.

[0079] That is, the blade drive device 4 is a blade drive device capable of adjusting the amount of light incident on the optical element through an aperture, and includes a stator 11 (fixed body) having a coil 111, a rotor 12 (movable body) having a magnet 121 and rotatable relative to the stator 11, and diaphragm blades 30 that open and close the aperture in conjunction with the rotation of the rotor 12. The magnet 121 is a ring-shaped multi-pole magnet in which south poles and north poles are arranged alternately in the circumferential direction, and has a first magnetic pole portion 21 having a first length in the circumferential direction and a second magnetic pole portion 22 having a second length in the circumferential direction that is shorter than the first length. The coil 111 is a planar coil having two circumferentially opposing portions 111a that face each other in the circumferential direction, and is arranged so that the magnetic flux of the magnet 121 and the circumferentially opposing portions 111a intersect in mutually opposite directions.

[0080] Specifically, in the blade drive device 4, the first magnetic pole portion 21 has the second magnetic pole portion 22 arranged on one circumferential side and the first magnetic pole portion 21 arranged on the other circumferential side, and the second magnetic pole portion 22 has the first magnetic pole portions 21 arranged on both circumferential sides. The coil 111 is arranged so that the magnetic fluxes formed by two adjacent first magnetic pole portions 21 intersect with the circumferential opposing portions 111a in mutually opposite directions.

[0081] By using the fluid support part 13, which is not rigid, as the support part that supports the rotor 12 relative to the stator 11, it is possible to reduce the size and height of the drive motor 10. In addition, the magnetic flux of the magnet 121 can be effectively utilized, and the power consumption of the blade drive device 4 can be reduced.

[0082] In the blade drive device 4, the magnet 121 has an unmagnetized neutral portion between two adjacent first magnetic pole portions 21, and a detection unit 116 that detects the rotational position of the magnet 121 is disposed at a portion facing the neutral portion 23 in the optical axis direction. This makes the change in the detection value of the detection unit 116 gentler, so that the rotational position of the rotor 12 (magnet 121) can be detected more easily than when the magnet 121 does not have the neutral portion 23 (see FIG. 11B).

[0083] In the blade drive device 4, the magnet 121 has a distinguishing means for distinguishing the ranges of the magnetic pole portions. Specifically, the distinguishing means can distinguish the ranges of magnetic pole portions that are adjacent in the circumferential direction and / or overlapping in the optical axis direction. By providing the distinguishing means in the magnet 121, the ranges of the first magnetic pole portion 21 and the second magnetic pole portion 22 can be clearly grasped, and the positions of the coil 111 and the magnet 121 in the circumferential direction can be appropriately adjusted.

[0084] The invention made by the inventor has been specifically described above based on an embodiment, but the present invention is not limited to the above embodiment and can be modified within the scope of the gist thereof.

[0085] For example, while the above embodiment has been described using a smartphone M as an example, the present invention can be applied to a camera-equipped device 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, notebook computers, tablet terminals, portable game consoles, web cameras, and camera-equipped in-vehicle devices (e.g., backup monitor devices, drive recorder devices). Transportation equipment includes, for example, automobiles and drones (unmanned aerial vehicles).

[0086] 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 A described in the above 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.

[0087] Furthermore, in the above embodiment, the optical element driving device 1 that drives the lens portion 2 as an optical element has been described, but the optical element to be driven may be an optical element other than a lens, such as a mirror or a prism.

[0088] Furthermore, the configurations of the coils 111 and magnets 121 that make up the drive motor 10 are not limited to those described in the embodiment and can be modified as appropriate. For example, the motor of the present invention can also be applied to a linear motor in which a movable body moves linearly relative to a fixed body.

[0089] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0090] 4 Blade drive device 10 Drive motor 11 Stator (fixed body) 12 Rotor (moving body) 13 Fluid support part 14 Regulatory Department 111 Coil 112 Base (housing) 115 Stator cover (damming member) 121 Magnet

Claims

1. a fixed body having a coil; a movable body having a magnet arranged opposite to the coil; a fluid support portion that supports the movable body movably relative to the fixed body; a restricting portion that restricts the distance between the magnet and the coil; Equipped with a motor.

2. the fluid support portion is formed of a magnetic fluid and forms a magnetic gap between the magnet and the coil. The motor of claim 1 .

3. The restricting portion is a rolling element. The motor of claim 1 .

4. The restricting portion is integrally formed with a component of the fixed body or the movable body. The motor of claim 1 .

5. the fixed body has a damming member that suppresses outflow of the fluid support portion. The motor of claim 1 .

6. The magnet is a ring-shaped multi-pole magnet in which south poles and north poles are arranged alternately in the circumferential direction, the coil is a planar coil having two portions facing each other in the circumferential direction, and is arranged such that the magnetic flux of the magnet intersects the two portions in opposite directions; the fluid support portion supports the magnet rotatably relative to the coil; The motor of claim 1 .

7. A blade drive device capable of adjusting the amount of light incident on an optical element through an opening, A motor according to claim 6; diaphragm blades that open and close the aperture in conjunction with the rotation of the movable body; A blade drive device comprising:

8. A camera module comprising the blade drive device according to claim 7.

9. A camera-equipped device that is an information device or a transportation device, A camera module according to claim 8, Camera-equipped device.

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