Optical element driving device, camera module, and camera mounting device

Abstract

The present invention provides an optical element drive unit, camera module, and camera mounting device suitable for dual-camera applications, which can suppress magnetic interference to adjacent optical element drive units. [Solution] The optical element driving device comprises a first magnet arranged along two opposing sides of a rectangular shape viewed from the optical axis direction in a first fixed part, a second magnet arranged along one of the two sides of the rectangular shape where the first magnet is not located, and a ring-shaped first coil arranged inside the rectangular shape in a first movable part so as to face the first and second magnets. The first and second magnets are plate-shaped magnets magnetized in the thickness direction, and the first coil has a proximity part that is close to the second magnet and a displacement part whose separation distance from the second magnet changes.

Description

Technical Field

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

Background Art

[0002] Generally, camera-mounted devices such as smartphones and drones are equipped with small camera modules (optical devices). A drone is an unmanned aircraft that can be flown by remote control or automatic control, and some are called multicopters.

[0003] An optical element driving device for driving an optical element such as a lens is used in the camera module. The optical element driving device has, for example, an autofocus function (hereinafter referred to as "AF function", AF: Auto Focus) that automatically focuses when shooting a subject by moving the optical element in the optical axis direction, and a shake correction function (hereinafter referred to as "OIS function", OIS: Optical Image Stabilization) that optically corrects shake (vibration) generated during shooting to reduce image blur.

[0004] For example, a voice coil motor composed of a magnet and a coil is applied to the drive source of the optical element driving device (see, for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] In recent years, the practical application of camera modules with multiple optical element drive devices, such as dual cameras, has been progressing. Dual cameras offer various possibilities depending on the application scenario, such as the ability to simultaneously capture two images with different focal lengths, or to simultaneously capture still and moving images.

[0007] In a dual camera system, two optical element drive units are positioned adjacent to each other. Therefore, if the voice coil motor described above is used as the drive source for each optical element drive unit, magnetic interference from the magnet of one optical element drive unit may cause the operation of the other optical element drive unit to become unstable. On the other hand, if the two optical element drive units are spaced far enough apart that magnetic interference does not occur, miniaturization of the camera module is hindered, which is disadvantageous for commercialization.

[0008] The object of the present invention is to provide an optical element drive device, a camera module, and a camera mounting device suitable for dual camera applications, which can suppress magnetic interference to adjacent optical element drive devices. [Means for solving the problem]

[0009] The optical element driving device according to the present invention is First fixing part and A first movable part that is movable in the optical axis direction relative to the first fixed part, The second fixing part, A second movable part that can move in a direction perpendicular to the optical axis relative to the second fixed part, The first fixing portion includes a first magnet arranged along two opposing sides of a rectangular shape as viewed from the optical axis direction, A second magnet is positioned along one of the two sides of the rectangular shape where the first magnet is not located, The first movable part comprises a ring-shaped first coil arranged inside the rectangular shape so as to face the first magnet and the second magnet, The first magnet and the second magnet are plate-shaped magnets magnetized in the thickness direction of the plate. The first coil has a proximity portion that is close to the second magnet and a displacement portion where the separation distance from the second magnet changes.

[0010] The camera module according to the present invention includes the above-described optical element driving device.

[0011] The camera mounting device according to the present invention is a camera mounting device that is an information device or a transportation device, and includes the above-described camera module.

Effect of the Invention

[0012] According to the optical element driving device, camera module, and camera mounting device of the present invention, magnetic interference with an adjacent optical element driving device can be suppressed, and the performance of a dual camera can be improved.

Brief Description of the Drawings

[0013] [Figure 1] FIGS. 1A and 1B are diagrams showing a smartphone on which a camera module according to an embodiment of the present invention is mounted. [Figure 2] FIG. 2 is an exploded perspective view of the camera module. [Figure 3] FIG. 3 is an exploded perspective view of the optical element driving device. [Figure 4] FIG. 4 is an exploded perspective view of the OIS movable part. [Figure 5] FIG. 5 is an exploded perspective view of the OIS movable part. [Figure 6] FIG. 6 is an exploded perspective view of the lens holder and the AF coil. [Figure 7] FIG. 7 is an exploded perspective view of the magnet holder and the driving magnet. [Figure 8] FIG. 8 is a plan view of the AF coil. [Figure 9] FIG. 9 is a diagram showing the arrangement of the AF coil and the driving magnet. [Figure 10]FIG. 10 is a cross-sectional view of the optical element driving device taken along line A-A in FIG. 9. [Figure 11] FIG. 11 is a cross-sectional view of the optical element driving device taken along line B-B in FIG. 9. [Figure 12] FIG. 12 is a cross-sectional view of the optical element driving device taken along line C-C in FIG. 9. [Figure 13] FIGS. 13A and 13B are views showing an automobile as a camera mounting device on which an in-vehicle camera module is mounted.

Embodiments for Carrying out the Invention

[0014] Hereinafter, embodiments of the present invention will be described in detail based on the drawings.

[0015] <Smartphone> FIGS. 1A and 1B are views showing a smartphone M (an example of a camera mounting device) on which a camera module A according to an embodiment of the present invention is mounted. 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 composed of two rear cameras OC1 and OC2. The camera module A according to the present embodiment is applied to at least one of the rear cameras OC1. Note that the other rear camera OC2 may have the same configuration as the camera module A according to the present embodiment, or another configuration having a driving source composed of a voice coil motor may be applied.

[0017] <Camera Module> FIG. 2 is an exploded perspective view of the camera module A. In the present embodiment, an orthogonal coordinate system (X, Y, Z) is used for explanation. The same orthogonal coordinate system (X, Y, Z) is also shown in the figures described later.

[0018] Camera module A is mounted on smartphone M such that, for example, the Z-axis direction is the optical axis direction, the upper side (+Z side) in the diagram is the light-receiving side along the optical axis, and the lower side (-Z side) is the image-forming side along the optical axis. The X-axis and Y-axis directions perpendicular to the Z-axis are referred to as the "orthogonal optical axis direction," and the XY plane is referred to as the "orthogonal optical axis plane." 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, which allows for automatic focusing when photographing a subject. Furthermore, camera module A is equipped with an OIS function, which optically corrects camera shake (vibration) that occurs during shooting, enabling the capture of blur-free images.

[0020] As shown in Figure 2, camera module A includes an optical element driving device 1, a lens unit 2, and an imaging unit 3, etc.

[0021] The optical element driving device 1 of this embodiment is designed with consideration for mounting on the camera module A, etc., as described above, and has a configuration in which the length in the Z-axis direction is shorter than the lengths in the X-axis direction and the Y-axis direction, that is, a configuration in which the height along the Z-axis direction is reduced.

[0022] The optical element driving device 1 is configured, for example, to allow the lens unit 2 to move in the direction of the optical axis and in the direction perpendicular to the optical axis. The optical element driving device 1 realizes AF (autofocus) and / or zoom functions by moving the lens unit 2 in the direction of the optical axis. Furthermore, the optical element driving device 1 realizes OIS (optical image stabilization) functions by moving the lens unit 2 in the direction perpendicular to the optical axis. A detailed description of the optical element driving device 1 will be given later.

[0023] The lens unit 2 has a lens and a lens barrel that holds the lens. The lens unit 2 is housed and fixed in the optical element driving device 1. The lens unit 2 is an example of an optical element that is driven by the optical element driving device 1. The optical element that is driven by the optical element driving device 1 may be an optical element other than a lens, such as a mirror or a prism.

[0024] The imaging unit 3 captures the subject image formed by the lens unit 2. The imaging unit 3 is positioned 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 substrate 3a, an image sensor 3b mounted on the image sensor substrate 3a, and a module control unit 3c.

[0025] The image sensor substrate 3a is, for example, a flexible printed circuit board (FPC) and is configured to transmit the imaging signal obtained by the image sensor 3b to the 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 3b is composed of, for example, a CCD (charge-coupled device) type image sensor, a CMOS (complementary metal oxide semiconductor) type image sensor, and captures the image of the subject formed by the lens unit 2.

[0027] The module control unit 3c is composed of, for example, a control IC and controls the operation of the optical element drive device 1 and the blade drive device 4. The optical element drive device 1 is mounted on the image sensor substrate 3a and is mechanically and electrically connected. The module control unit 3c may be provided on the image sensor substrate 3a, or it may be provided on a camera-mounted device (in this embodiment, a smartphone M) on which the camera module A is mounted.

[0028] <Optical element driving device> Figure 3 is an exploded perspective view of the optical element driving device 1. Figures 4 and 5 are exploded perspective views of the OIS movable part 10. Figure 4 is an upward perspective view, and Figure 5 is a downward perspective view. As shown in Figures 3 to 5, the optical element driving device 1 includes the OIS movable part 10, the OIS fixed part 20, the OIS driving part 30, the OIS support part 40, the cover 24, etc. Note that the cover 24 is omitted in Figure 3.

[0029] The cover 24 is the exterior of the optical element drive device 1 and covers the outside of the drive device body (reference numeral omitted). The cover 24 is a covered rectangular cylinder that is roughly rectangular in shape when viewed from the Z-axis direction. The shape of the cover 24 in plan view is, for example, square. That is, the optical element drive device 1 has a rectangular shape that extends in the X-axis direction and the Y-axis direction when viewed from the Z-axis direction. In the following description, "plan view" means a plan view when viewed from the Z-axis direction.

[0030] The cover 24 has a substantially circular opening 241 on the light-receiving side (top surface) in the optical axis direction. The lens portion 2 faces outward from the opening 241 of the cover 24. The lens portion 2 may be positioned to protrude from the opening surface of the cover 24 towards the light-receiving side in the Z axis direction. The cover 24 is fixed to the base 21 of the optical element driving device 1 by adhesive, for example. The cover 24 may be formed of a magnetic material, for example, and may have a shielding function that blocks the incidence of electromagnetic waves from the outside or the radiation of electromagnetic waves to the outside.

[0031] The OIS movable part 10 is the part that oscillates in a plane perpendicular to the optical axis by receiving the driving force of the OIS drive unit 30 during shake correction. The OIS fixed part 20 is the part that supports the OIS movable part 10. The OIS fixed part 20 is, for example, positioned spaced apart from the OIS movable part 10 on the imaging side in the optical axis direction.

[0032] The OIS drive unit 30 consists of OIS coils 32A to 32C arranged in the OIS fixed unit 20 and drive magnets 31A to 31C (OIS magnets) arranged in the OIS movable unit 10. In other words, a moving magnet type voice coil motor is applied to the OIS drive unit 30. Note that the OIS drive unit 30 may also be composed of a moving coil type voice coil motor.

[0033] The OIS support portion 40 is the part that connects the OIS movable portion 10 and the OIS fixed portion 20. The OIS support portion 40 supports the OIS movable portion 10 so that it can swing within a plane perpendicular to the optical axis relative to the OIS fixed portion 20.

[0034] The optical element drive device 1 has a defined guaranteed stroke that indicates the degree to which proper vibration correction can be performed. Specifically, the shape, size, and strength of the components of the OIS movable part 10, OIS fixed part 20, OIS drive part 30, and OIS support part 40 are set to achieve the guaranteed stroke.

[0035] The OIS movable part 10 is composed of an AF unit including, for example, a lens holder 11, a magnet holder 12, an AF coil 13, drive magnets 31A to 31C, an upper elastic support part 15, and a lower elastic support part 16. The OIS movable part 10 may also have an AF drive circuit board that controls the operation of the lens holder 11 (AF movable part). The AF drive circuit board includes, for example, a flexible printed circuit board and a driver IC.

[0036] The lens holder 11 holds the lens unit 2 (see Figure 2) and is a movable body (AF movable part) that moves in the Z-axis direction when focusing. The lens holder 11 is positioned radially inward and spaced apart from the magnet holder 12, and is connected to the magnet holder 12 by an upper elastic support part 15 and a lower elastic support part 16.

[0037] The lens holder 11 is formed from, for example, polyarylate (PAR), a PAR alloy obtained by mixing multiple resin materials including PAR, or a liquid crystal polymer.

[0038] The lens holder 11 has a cylindrical lens housing portion 111. The lens portion 2 (see Figure 3) is fixed to the inner circumferential surface of the lens housing portion 111, for example, by adhesive. The lens holder 11 also has a coil winding portion 112 on its outer circumferential surface (see Figure 6). An AF coil 13 is attached to the coil winding portion 112. The coil winding portion 112 has a pentagonal shape in plan view, for example.

[0039] An upper elastic support portion 15 is fixed to the upper surface of the lens holder 11 (the upper end surface of the lens housing portion 111). The upper elastic support portion 15 is positioned, for example, by a positioning boss (not shown in the reference numerals) provided on the upper surface of the lens holder 11.

[0040] A lower elastic support portion 16 is fixed to the lower surface of the lens holder 11. The lower elastic support portion 16 is positioned, for example, by a positioning boss (not shown in the reference numeral) provided on the lower surface of the lens holder 11.

[0041] The magnet holder 12 is a fixed body (AF fixing part) that supports the lens holder 11 so that it can move in the Z-axis direction via an upper elastic support part 15 and a lower elastic support part 16. The magnet holder 12 has, for example, a roughly rectangular cylindrical shape in plan view. The lens holder 11 is placed in the opening 121 of the magnet holder 12.

[0042] The magnet holder 12 is formed from a molding material consisting of, for example, polyarylate (PAR), a PAR alloy (e.g., PAR / PC) which is a mixture of multiple resin materials including PAR, or a liquid crystal polymer.

[0043] The magnet holder 12 has magnet housings 123 on the inside of three of its four side walls 122, where the drive magnets 31A to 31C are fixed (see Figure 7). The magnet housings 123 are provided with, for example, an opening (not shown in the reference numerals) that communicates with the outside, allowing adhesive to be injected into the contact surface between the magnet housings 123 and the drive magnets 31A to 31C.

[0044] The magnet holder 12 has a wire insertion portion 124 on the outside of the connecting portion of the side wall 122, which is recessed radially inward in an arc shape. Suspension wires 41 to 44 are arranged in the wire insertion portion 124. By providing the wire insertion portion 124, interference between the suspension wires 41 to 44 and the magnet holder 12 can be avoided when the OIS movable part 10 swings.

[0045] An upper elastic support portion 15 is fixed to the upper surface of the side wall 122. A lower elastic support portion 16 is fixed to the lower surface of the side wall 122. The periphery of the wire insertion portion 124 is formed to be inclined downward from the mounting surface of the upper elastic support portion 15, so that a gap is formed when the upper elastic support portion 15 is attached.

[0046] The AF coil 13 is a ring-shaped air-core coil that is energized during autofocus. The AF coil 13 is wound around the coil winding section 112 of the lens holder 11. The AF coil 13, together with the drive magnets 31A and 31B, constitutes a voice coil motor and functions as an AF drive unit. Both ends of the AF coil 13 are wound around the winding sections (not shown) of the lens holder 11. The AF coil 13 is energized, for example, via the upper elastic support section 15. The current supplied to the AF coil 13 is controlled, for example, by the module control section 3c.

[0047] The drive magnets 31A to 31C are fixed to the magnet holder 12, for example, by adhesive. The drive magnets 31A to 31C are positioned radially apart from the AF coil 13 and apart in the optical axis direction from the OIS coils 32A to 32C. In the drive magnets 31A to 31C, the light-receiving half in the optical axis direction faces the AF coil 13. Also, in the drive magnets 31A to 31C, the imaging side surface in the optical axis direction faces the OIS coils 32A to 32C.

[0048] The drive magnets 31A to 31C are two-pole magnets in the shape of a plate, magnetized in the thickness direction. The drive magnets 31A to 31C are fixed to the magnet holder 12 such that, for example, the inner surface facing the AF coil 13 is the north pole and the outer surface is the south pole. The drive magnets 31A and 31B have similar configurations and the same magnetic force. The drive magnet 31C may have the same configuration as the drive magnets 31A and 31B, or it may have a different configuration. That is, the magnetic force of the drive magnets 31A and 31B and the drive magnet 31C may be the same or different.

[0049] The driving magnets 31A and 31B are arranged along two sides of the rectangular shape of the magnet holder 112 that are opposite each other in the Y-axis direction when viewed from the optical axis direction. The driving magnet 31C is arranged along one of the two sides of the rectangular shape of the magnet holder 112 where the driving magnets 31A and 31B are not located. In the magnet holder 112, the side opposite the driving magnet 31C in the X-axis direction is a magnet-free area where no magnet is located. By arranging the camera module A such that the magnet-free area of ​​the optical element driving device 1 is located on the side of the adjacent optical element driving device, magnetic interference with other adjacent optical element driving devices can be suppressed.

[0050] The upper elastic support portion 15 elastically supports the lens holder 11 relative to the magnet holder 12 on the light-receiving side in the optical axis direction. The upper elastic support portion 15 is made of, for example, titanium copper, nickel copper, stainless steel, etc. The upper elastic support portion 15 as a whole has a rectangular shape in plan view, that is, the same shape as the magnet holder 12.

[0051] The upper elastic support portion 15 is composed of a plurality of upper spring elements (for example, two). The plurality of upper spring elements are arranged so as not to contact each other and function as a leaf spring. The upper spring elements are formed, for example, by etching a single sheet of metal. The upper spring elements, together with the suspension wires 41-44, function as an AF power line. If an AF drive circuit board is provided in the OIS movable portion 10, the upper elastic support portion 15 may be used as an AF signal line and a common power line.

[0052] The lower elastic support portion 16 elastically supports the lens holder 11 relative to the magnet holder 12 on the optical axis imaging side. The lower elastic support portion 16 is made of, for example, titanium copper, nickel copper, stainless steel, etc. The lower elastic support portion 16 as a whole has a rectangular shape in plan view, that is, the same shape as the magnet holder 12.

[0053] The lower elastic support portion 16 is composed of a plurality of lower spring elements (for example, two). The plurality of lower spring elements are arranged so as not to contact each other and function as a leaf spring. The lower spring elements are formed, for example, by etching a single sheet of metal. If an AF drive circuit board is provided in the OIS movable portion 10, the lower elastic support portion 16 may be used as a coil power supply line that supplies power from the AF drive circuit board to the AF coil 13.

[0054] Although not shown in the diagram, the OIS movable part 10 may also have an AF position detection unit. The AF position detection unit consists of, for example, an AF detection sensor placed on the magnet holder 12 and an AF detection magnet placed on the lens holder 11. The AF detection sensor magnetically detects the movement of the lens holder 11. The AF detection sensor is, for example, a magnetic sensor such as a Hall element or a TMR (Tunnel Magneto Resistance) sensor.

[0055] The OIS fixing section 20 is composed of, for example, a base 21 and OIS coils 32A to 32C.

[0056] The base 21 has a rectangular shape in plan view, with a circular opening 211 formed in the center. In camera module A, an image sensor substrate 3a on which an image sensor 3b is mounted is positioned on the optical axis imaging side of the base 21.

[0057] The base 21 has wiring connectors 23 embedded in it, for example, by insert molding. The wiring connectors 23 are electrically connected to the wiring pattern of the image sensor substrate 3a and form power lines for supplying power to the OIS coils 32A to 32C and the AF coil 13. The wiring connectors are exposed from the four corners of the base 21 and connected to the suspension wires 41 to 44 by soldering.

[0058] The OIS coils 32A to 32C are positioned opposite the drive magnets 31A to 31C in the optical axis direction. The OIS coils 32A to 32C are air-core coils that are energized during vibration correction. The size and arrangement of the OIS coils 32A to 32C and the drive magnets 31A to 31C are set so that the radial edges of the drive magnets 31A to 31C fit within the cross-sectional width of each OIS coil 32A to 32C, that is, so that the magnetic field radiated from the bottom surface of the drive magnets 31A to 31C crosses two opposing sides of the OIS coils 32A to 32C and returns to the drive magnets 31A to 31C.

[0059] Here, the OIS coils 32A to 32C have a shape similar to the planar shape (in this case, rectangular shape) of the drive magnets 31A to 31C. This allows for efficient generation of the driving force (electromagnetic force) necessary to oscillate the OIS movable part 10 in the plane orthogonal to the optical axis. The current supplied to the OIS coils 32A to 32C is controlled, for example, by the module control unit 3c.

[0060] Although not shown in the diagram, an OIS detection sensor may be mounted on the base 21. The OIS detection sensor is located on the OIS fixed part 20 and magnetically detects the operation of the OIS movable part 10. The OIS detection sensor is a magnetic sensor such as a Hall element or a TMR (Tunnel Magneto Resistance) sensor. The OIS detection sensor is located, for example, at two locations facing the drive magnets 31B and 31C in the optical axis direction and mainly detects the magnetic flux of the drive magnets 31B and 31C. The OIS detection sensor is located, for example, in the air core portion of the OIS coils 32B and 32C.

[0061] The OIS support section 40 is composed of multiple wire members. In this embodiment, the OIS support section 40 is composed of four suspension wires 41 to 44. The suspension wires 41 to 44 are arranged at the four corners of a rectangular shape in plan view. The suspension wires 41 to 44 are linear members extending in the direction of the optical axis and elastically deform as the OIS movable section 10 swings. One end of each suspension wire 41 to 44 (the end on the light-receiving side in the optical axis direction, the upper end) is fixed to the OIS movable section 10, and the other end (the end on the image-forming side in the optical axis direction) is fixed to the OIS fixed section 20. The suspension wires 41 to 44 are electrically and mechanically connected, for example, to the upper elastic support section 15 of the OIS movable section 10 and the wiring fittings 23 of the OIS fixed section 20. Two of the suspension wires 41 to 44 function, for example, as AF power lines. Furthermore, if the AF drive circuit board is provided in the OIS movable part 10, the OIS support part 40 may be used as the AF signal line and common power supply line.

[0062] As described above, the drive magnets 31A and 32B are arranged along two opposing sides of the rectangular shape, and the drive magnet 31C is arranged along the other side. In this case, the portions of the AF coil 13 facing each other in the Y-axis direction generate driving forces of the same magnitude in the same direction in the optical axis direction due to the action of the magnetic fields of the drive magnets 31A and 32B, so no moment is generated in the lens holder 11 around the X-axis. In contrast, in the portions of the AF coil 13 facing each other in the X-axis direction, a driving force is generated on one side due to the action of the magnetic field of the drive magnet 31C, but no driving force is generated on the other side, so a moment is generated in the lens holder 11 around the Y-axis. As a result, the posture of the lens holder 11 when moving it in the optical axis direction becomes unstable, which may reduce autofocus performance. In this embodiment, the structure of the AF coil 13 and the drive magnet 31C is such that the drive magnet 31C does not substantially function as an AF drive unit.

[0063] In other words, the AF coil 13 is wound along the coil winding section 112 of the lens holder 11 and has a pentagonal shape in plan view (see Figure 8). Specifically, the AF coil 13 has first straight sections 131A, 131B, second straight sections 132A, 132B, and a third straight section 133. The first straight sections 131A and 131B face each other. One end of the second straight sections 132A and 132B is connected to the other, and the other end is connected to the end of the first straight sections 131A and 131B, respectively. The third straight section 133 connects the first straight sections 131A and 131B. The pentagonal shape of the AF coil 13 includes a so-called rounded pentagonal shape, where the vertices have an arc shape.

[0064] As shown in Figure 9, the first linear sections 131A and 131B of the AF coil 13 are positioned to face the drive magnets 31A and 31B in the Y-axis direction, respectively. The second linear sections 132A and 132B of the AF coil 13 are positioned to face the drive magnet 31C in the X-axis direction.

[0065] The AF coil 13 is in close proximity to the drive magnet 31C at the vertex 134, which is the intersection of the second linear sections 132A and 132B. As the second linear sections 132A and 132B move away from the vertex 134, the distance between them and the drive magnet 31C increases. In other words, the second linear sections 132A and 132B are displacement sections in which the distance between them and the drive magnet 31C changes.

[0066] Figure 10 is a cross-sectional view of the optical element driving device 1 along line AA in Figure 9. As shown in Figure 10, the magnetic fields MF of the driving magnets 31A and 31B intersect with the AF coil 13 in the Y-axis direction and with the OIS coils 32A and 32B in the Z-axis direction, respectively. In other words, the driving magnets 31A and 31B together with the AF coil 13 constitute a voice coil motor and function as an AF driving unit. Furthermore, the driving magnets 31A and 31B together with the OIS coils 32A and 32B constitute a voice coil motor and function as an OIS driving unit 30. In this embodiment, the driving magnets 31A and 31B serve as both AF magnets and OIS magnets.

[0067] The distance between the AF coil 13 and the drive magnets 31A and 31B is constant along the entire length of the first straight sections 131A and 131B of the AF coil 13. Since the magnetic fields of the drive magnets 31A and 31B act uniformly on the AF coil 13, the driving efficiency is improved. Therefore, even if the drive magnet 31C does not substantially function as an AF drive unit, sufficient driving force can be secured by the drive magnets 31A and 31B.

[0068] Figure 11 is a cross-sectional view of the optical element driving device 1 along the BB line in Figure 9. Figure 12 is a cross-sectional view of the optical element driving device 1 along the CC line in Figure 9. As shown in Figures 11 and 12, the magnetic field MF of the driving magnet 31C intersects with the OIS coil 32C in the Z-axis direction. The driving magnet 31C, together with the OIS coil 32C, constitutes a voice coil motor and functions as an OIS driving unit 30.

[0069] On the other hand, the AF coil 13 is locally close to the drive magnet 31C at its apex 134. In other words, the magnetic field MF of the drive magnet 31C does not significantly affect the second linear sections 132A and 132B (see Figure 12). As a result, the influence of the magnetic field MF of the drive magnet 31C is significantly reduced compared to when the AF coil 13 is formed in a rectangular shape. Therefore, the moment that may occur around the Y axis relative to the lens holder 11 can be reduced, and the lens holder 11 can be moved in a stable position. Furthermore, since it is not necessary to increase the distance between the AF coil 13 and the drive magnet 31C in order to reduce the influence of the magnetic field MF of the drive magnet 31C on the AF coil 13, the size of the lens holder 11 in plan view can be reduced.

[0070] Furthermore, the apex 134 of the AF coil 13 faces the central portion of the drive magnet 31C in the longitudinal direction. This allows for minimizing the influence of the magnetic field of the drive magnet 31C on the second straight sections 132A and 132B of the AF coil 13 while ensuring space for the lens housing section 111 in the lens holder 11.

[0071] Furthermore, a yoke 33 is positioned on the surface of the drive magnet 31C facing the AF coil 13. The yoke 33 has a first yoke portion 331 and a second yoke portion 332. The yoke 33 is interposed between the drive magnet 31C and the AF coil 13. The yoke 33 is made of a magnetic material and forms a magnetic circuit together with the drive magnet 31C.

[0072] The first yoke portion 331 is positioned in the portion of the drive magnet 31C that faces the AF coil 13 (the half on the light-receiving side in the optical axis direction). The first yoke portion 331 shields the magnetic field acting from the drive magnet 31C on the AF coil 13. Since the effect of the magnetic field of the drive magnet 31C on the AF coil 13 is reduced, the moment that may occur around the Y axis with respect to the lens holder 11 can be further reduced, improving the stability when moving the lens holder 11.

[0073] In the drive magnet 31C, the portion in close proximity to the AF coil 13 experiences a greater magnetic field effect on the AF coil 13. The first yoke portion 331 is positioned only in the central portion in the longitudinal direction of the drive magnet 31C, corresponding to the portion where the magnetic field effect on the AF coil 13 is greatest, i.e., the portion corresponding to the apex 134 of the AF coil 13, and does not need to be positioned in the portions corresponding to the second linear portions 132A and 132B. In this case, the weight of the yoke 33 can be reduced. Note that the influence of the magnetic field of the drive magnet 31C on the second linear portions 132A and 132B is minor, so it is not a problem if the first yoke portion 331 is not positioned there.

[0074] The second yoke portion 332 is positioned on the half of the surface of the drive magnet 31C facing the AF coil 13, on the side facing the image formation in the optical axis direction. The length of the second yoke portion 332 is the same as that of the drive magnet 31C. That is, the second yoke portion 332 is formed along the entire length of the drive magnet 31C. By providing the second yoke portion 332, the magnetic flux of the drive magnet 31C can be efficiently intersected with the OIS coil 32C.

[0075] When vibration correction is performed in the optical element drive device 1, power is supplied to the OIS coils 32A to 32C. Specifically, in the OIS drive unit 30, the current supplied to the OIS coils 32A to 32C is controlled based on the detection signal from the vibration detection unit (not shown, e.g., gyro sensor) so that the vibration of the camera module A is canceled out. At this time, the oscillation of the OIS movable part 10 can be accurately controlled by feeding back the detection result from the magnetic sensor (not shown).

[0076] When current is applied to the OIS coils 32A to 32C, a Lorentz force is generated in the OIS coils 32A to 32C due to the interaction between the magnetic field of the drive magnets 31A to 31C and the current flowing through the OIS coils 32A to 32C (Fleming's left-hand rule). 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 the long side portion of the OIS coils 32A to 32C. Since the OIS coils 32A to 32C are fixed, a reaction force acts on the drive magnets 31A to 31C. This reaction force becomes the driving force of the OIS voice coil motor, causing the OIS movable part 10, which has the drive magnets 31A to 31C, to oscillate in the XY plane, and vibration correction is performed.

[0077] When autofocus is performed in the optical element driving device 1, the AF coil 13 is energized. When the AF coil 13 is energized, a Lorentz force is generated in the AF coil 13 due to the interaction between the magnetic fields of the driving magnets 31A and 31B and the current flowing through the AF coil 13. The direction of the Lorentz force is perpendicular to the direction of the magnetic fields from the driving magnets 31A and 31B and the direction of the current flowing through the AF coil 13 (Z-axis direction). Since the driving magnets 31A and 31B are fixed, a reaction force acts on the AF coil 13. This reaction force becomes the driving force of the AF voice coil motor, causing the lens holder 11 (AF movable part) on which the AF coil 13 is located to move in the optical axis direction, and autofocus is performed.

[0078] In this embodiment, the effect of the magnetic field of the drive magnet 31C on the AF coil 13 is suppressed, and the moment that may occur around the Y axis relative to the lens holder 11 is negligible, so the lens holder 11 can be moved in a stable position.

[0079] Thus, this embodiment discloses an optical element driving device 1 and a camera module A that are equipped with the following features individually or in appropriate combinations.

[0080] In other words, the optical element driving device 1 comprises a magnet holder 12 (first fixed part), a lens holder 11 (first movable part) that can move in the optical axis direction relative to the magnet holder 12, an OIS fixed part 20 (second fixed part), an OIS movable part 10 (second movable part) that can move in a direction perpendicular to the optical axis relative to the OIS fixed part 20, driving magnets 31A and 31B (first magnets) arranged along two opposing sides of the rectangular shape of the magnet holder 12 as viewed from the optical axis direction, a driving magnet 31C (second magnet) arranged along one of the two sides where the rectangular driving magnets 31A and 31B are not arranged, and a ring-shaped AF coil 13 (first coil) arranged inside the rectangular shape of the lens holder 11 so as to face the driving magnets 31A to 31C (first and second magnets). The drive magnets 31A to 31C are plate-shaped magnets magnetized in the thickness direction, and the AF coil 13 has a proximity portion that is close to the drive magnet 31C and a displacement portion that changes the distance from the drive magnet 31C.

[0081] Specifically, the AF coil 13 (first coil) has two first straight sections 131A and 131B facing the two drive magnets 31A and 31B (first magnets), and two second straight sections 132A and 132B facing the drive magnet 31C (second magnet). The intersection of the two second straight sections 132A and 132B is the proximity section, and the second straight sections 132A and 132B are the displacement sections.

[0082] According to the optical element driving device 1, by positioning the camera module A such that the magnet-free section where the driving magnets 31A to 31C are not located is on the side of the adjacent optical element driving device, magnetic interference with other adjacent optical element driving devices can be suppressed, thereby improving the performance of the dual camera.

[0083] Furthermore, the AF coil 13 (first coil) is locally close to the drive magnet 31C (second magnet) at its apex 134, and the magnetic field of the drive magnet 31C does not significantly affect the second linear sections 132A and 132B. Therefore, the influence of the drive magnet 31C's magnetic field on the AF coil 13 is reduced. Consequently, the moment that may occur around the Y-axis with respect to the lens holder 11 can be reduced, allowing the lens holder 11 to move in a stable position.

[0084] Furthermore, since it is not necessary to increase the distance between the AF coil 13 and the drive magnet 31C in order to reduce the influence of the magnetic field of the drive magnet 31C on the AF coil 13, the size of the lens holder 11 in plan view can be reduced.

[0085] In the optical element driving device 1, the apex portion 134 (proximity portion) of the AF coil 13 faces the central portion in the longitudinal direction of the driving magnet 31C (second magnet). This makes it possible to minimize the influence of the magnetic field of the driving magnet 31C on the second linear portions 132A and 132B of the AF coil 13 while securing space for the lens housing portion 111 in the lens holder 11.

[0086] In the optical element driving device 1, the distance between the AF coil 13 (first coil) and the driving magnets 31A and 31B (first magnets) is constant along the entire length of the first straight sections 131A and 131B of the AF coil 13. As a result, even if the driving magnet 31C (second magnet) does not substantially function as an AF drive unit, sufficient driving force can be secured by the driving magnets 31A and 31B.

[0087] Furthermore, the optical element drive device 1 is equipped with a yoke positioned on the surface of the drive magnet 31C (second magnet) that faces the AF coil 13 (first coil). This reduces the effect of the magnetic field of the drive magnet 31C on the AF coil 13, thereby improving the stability when moving the lens holder 11.

[0088] Furthermore, the optical element driving device 1 includes an OIS coil 32C (second coil) positioned in the OIS fixing section 20 (second fixing section) so as to face the driving magnet 31C (second magnet) in the optical axis direction, and the yoke 33 has a first yoke section 331 positioned in the portion facing the AF coil 13 (first coil), and a second yoke section 332 formed on the OIS coil 32C side of the first yoke section 331 over the entire length of the driving magnet 31C.

[0089] In the optical element driving device 1, the first yoke portion 331 is positioned opposite the apex portion 134 (proximity portion) of the AF coil 13, but is not positioned opposite the second linear portions 132A and 132B (displacement portions). This reduces the effect of the magnetic field of the driving magnet 31C (second magnet) on the AF coil 13 and also reduces the weight of the yoke 33.

[0090] Although the present invention has been specifically described above based on embodiments, the present invention is not limited to the above embodiments and can be modified without departing from its spirit.

[0091] For example, although the above embodiment was described using a smartphone M as an example, the present invention can be applied to a camera-mounted device having a camera module and an image processing unit that processes image information obtained by the camera module. The camera-mounted device includes information equipment and transportation equipment. Information equipment includes, for example, mobile phones with cameras, notebook computers, tablet terminals, portable game consoles, webcams, and in-vehicle devices with cameras (e.g., rearview monitors, drive recorders). Transportation equipment includes, for example, automobiles and drones (unmanned aerial vehicles).

[0092] Figures 13A and 13B show a vehicle V as a camera-mounted device equipped with an in-vehicle camera module VC (Vehicle Camera). Figure 13A is a front view of vehicle V, and Figure 13B is a rear perspective view of vehicle V. Vehicle V is equipped with the camera module A described in the above embodiment as the in-vehicle camera module VC. As shown in Figures 13A and 13B, the in-vehicle camera module VC can be mounted, for example, on the windshield facing forward or on the rear gate facing backward. This in-vehicle camera module VC is used for purposes such as a backup monitor, a drive recorder, collision avoidance control, and autonomous driving control.

[0093] In this embodiment, the AF coil 13 (first coil) has a pentagonal shape, but it may also have a polygonal shape with hexagons or more. Also, in this embodiment, the portion of the AF coil 13 facing the drive magnet 31C (second magnet) is formed by two second straight sections 132A and 132B, but it may also be formed in an overall arc shape.

[0094] Furthermore, in this embodiment, a yoke 33 is arranged on the surface of the drive magnet 31C (second magnet) facing the AF coil 13 (first coil), but the yoke 33 may be omitted.

[0095] In this embodiment, the present invention is applied to a so-called barrel-shift type optical element driving device 1 in which the OIS movable part 10, including the lens holder 11 (first movable part) and the magnet holder 12 (first fixed part), moves in a direction perpendicular to the optical axis relative to the OIS fixed part 20. However, the present invention can also be applied to a sensor-shift type optical element driving device. In a sensor-shift type optical element driving device, the OIS movable part on which the image sensor is mounted moves in a direction perpendicular to the optical axis relative to the OIS fixed part, which includes the lens holder (first movable part) and the magnet holder (first fixed part).

[0096] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of symbols]

[0097] 1 Optical element drive unit, 2 Lens unit (optical element), 3 Imaging unit, 10 OIS movable unit, 11 Lens holder (first movable unit), 12 Magnet holder (first fixed unit), 13 AF coil (first coil), 131A, 131B First straight section, 132A, 132B Second straight section (displacement section), 133 Third straight section, 134 Apex section (proximity section), 15 Upper elastic support unit, 16 Lower elastic support unit, 20 OIS fixed unit (second fixed unit), 21 Base, 30 OIS drive unit, 31A, 31B Drive magnet (first magnet), 31C Drive magnet (second magnet), 32A~32C OIS coil (second coil), 33 Yoke, 331 First yoke section, 332 Second yoke section, 40 OIS support unit, A Camera module, M Smartphone (device with camera)

Claims

1. First fixing part and A first movable part that is movable in the optical axis direction relative to the first fixed part, The second fixing part and A second movable part that can move in a direction perpendicular to the optical axis relative to the second fixed part, The first fixing portion includes a first magnet arranged along two opposing sides of a rectangular shape as viewed from the optical axis direction, A second magnet is positioned along one of the two sides of the rectangular shape where the first magnet is not located, The first movable part includes a ring-shaped first coil arranged inside the rectangular shape so as to face the first magnet and the second magnet, The first magnet and the second magnet are plate-shaped magnets magnetized in the thickness direction of the plate. The first coil has a proximity portion that is close to the second magnet and a displacement portion that changes the distance between it and the second magnet. Optical element driving device.

2. The first coil has two first linear sections facing each of the two first magnets, and two second linear sections facing the second magnet. The intersection of the two aforementioned second straight sections is the proximity section. The second linear portion is the displacement portion. The optical element driving device according to claim 1.

3. The proximity portion is opposite to the central portion in the longitudinal direction of the second magnet, The optical element driving device according to claim 1.

4. The distance between the first coil and the first magnet is constant along the entire length of the first straight section. The optical element driving device according to claim 2.

5. The second magnet comprises a yoke positioned on the surface facing the first coil, The optical element driving device according to claim 1.

6. The second fixing portion includes a second coil that is positioned opposite the second magnet in the direction of the optical axis, The yoke has a first yoke portion positioned opposite the first coil, and a second yoke portion formed on the second coil side of the first yoke portion over the entire length of the second magnet. The optical element driving device according to claim 5.

7. The first yoke portion is positioned in the portion opposite to the proximity portion, and is not positioned in the portion opposite to the displacement portion. The optical element driving device according to claim 6.

8. The optical element driving device is provided as described in claim 1. Camera module.

9. A camera-equipped device which is an information device or a transport device, A camera module comprising the camera module described in claim 8, A device equipped with a camera.

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