Blur correction device and imaging apparatus

Abstract

To provide a blur correction device which can be reduced in size and an imaging apparatus.SOLUTION: The blur correction device includes a fixed part which has a fixed member including a magnetic body, a movable part which has a movable member 21 for holding an imaging element and is configured to be movable with respect to the fixed member in a plane crossing an optical axis, and a magnetic driving part which moves the movable part in the plane and performs blur correction by the movement of the movable member 21 in the plane. In the movable member 21, a movable part magnet 80 is arranged. The movable part is magnetically energized to the fixed part on the basis of a magnetic force generated between the movable part magnet 80 and the fixed member and a magnetic force generated in the positions of the magnetic attraction plates 71Ya, 71Yb, 71X1, and 71X2 of the magnetic driving part.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a motion compensation device and an imaging device, and more particularly to a motion compensation device and an imaging device that perform motion compensation by moving a movable member that holds an imaging element within a plane that intersects with the optical axis direction. [Background technology]

[0002] In recent years, small, lightweight, and highly functional mirrorless digital cameras have become popular, and manufacturers are competing to develop even smaller, lighter, and higher image quality mirrorless digital cameras.

[0003] This type of mirrorless digital camera is equipped with a shake correction device having an in-body image stabilizer (IBIS) function that can achieve high-performance image stabilization to enable high-quality photographs and video shooting.

[0004] Furthermore, in cameras equipped with an IBIS function, in order to reduce the size of the camera body, it is necessary to reduce the size of the image stabilization device having the IBIS function.

[0005] Conventionally, there are image stabilization devices that can be made compact, such as those described in Patent Documents 1 and 2.

[0006] The image stabilization device described in Patent Document 1 includes a fixed section in which a plurality of coils are arranged, a movable section including a plurality of magnets arranged opposite the plurality of coils and an image sensor, a support member that supports the movable section relative to the fixed section so that the movable section is movable along a plane perpendicular to the optical axis of light incident on the image sensor, a detection means that detects the position of the movable section, and a control means that controls current to be passed through the plurality of coils based on the output of the detection means, and the plurality of coils are arranged opposite each other along the plane perpendicular to the optical axis. The device includes at least three coil groups, each of which is made up of two coils arranged in a radial pattern centered on a predetermined position intersecting the optical axis, thereby achieving miniaturization of the device.

[0007] Moreover, the drive device constituting the image stabilization device described in Patent Document 2 is a drive device that includes a fixed part, a movable part arranged to be movable in a plane relative to the fixed part via three rolling members, and an image sensor held by the movable part, and drives the movable part with multiple actuators. The multiple actuators are arranged only on two adjacent sides of the four outer periphery sides of the image sensor, and the outer periphery of one of three surrounding parts of the three rolling members provided on the movable part is abutted against a restricting member provided on the fixed part to restrict the movement range of the movable part, thereby achieving miniaturization of the device. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2016-170339 A [Patent Document 2] JP 2021-144165 A Summary of the Invention [Problem to be solved by the invention]

[0009] One embodiment of the technique of the present disclosure provides a blur correction device and an imaging device that can be made compact. [Means for solving the problem]

[0010] The invention according to a first aspect is a blur correction device that has a fixed part having a fixed member including a magnetic material, a movable part that has an image sensor and is configured to be movable relative to the fixed part within a plane intersecting the optical axis, and a magnetic drive part that moves the movable part within the plane, and performs blur correction by movement of the movable part within the plane, the blur correction device including a movable part magnet arranged on the movable part, and magnetically biases the movable part toward the fixed part based on magnetic force generated between the movable part magnet and the fixed member and magnetic force generated at the position of the magnetic drive part.

[0011] In the image stabilizer according to the second aspect of the present invention, in the first aspect, it is preferable that the movable member is made of a non-magnetic material.

[0012] A third aspect of the image stabilizer of the present invention is preferably such that, in the first or second aspect, the imaging element has a first side and a second side opposite the first side, the first side is located opposite the position of the magnetic drive unit, and the movable part magnet is arranged on a movable member corresponding to the second side of the imaging element.

[0013] A fourth aspect of the image stabilizer of the present invention is preferably such that, in the first or second aspect, the imaging element has a first corner and a second corner opposite the first corner, the first corner is located opposite the position of the magnetic drive unit, and the movable part magnet is arranged on the movable member corresponding to the second corner of the imaging element.

[0014] A blur correction device according to a fifth aspect of the present invention is preferably the first or second aspect, wherein the movable-part magnet is disposed on a movable member corresponding to a different side or corner of the imaging element with respect to the position of the magnetic drive part.

[0015] A sixth aspect of the present invention is directed to a motion compensation device according to any one of the first to fifth aspects, wherein the movable-part magnet is preferably arranged so that at least a portion of the movable-part magnet overlaps with the imaging element when viewed from the optical axis direction.

[0016] A blur correction device according to a seventh aspect of the present invention is any of the first to sixth aspects, wherein the movable-part magnet is preferably arranged in a position that does not overlap with the pixel range of the imaging element when viewed from the optical axis direction.

[0017] In an eighth aspect of the image stabilization device of the present invention, in any one of the first to seventh aspects, it is preferable that the magnetic drive unit is composed of a plurality of voice coil motors including a plurality of coils arranged on the movable member and a plurality of fixed part magnets arranged on the fixed member, the movable part has a plurality of magnetic attracting bodies at positions facing the plurality of fixed part magnets, respectively, and the movable part is magnetically biased to the fixed part by magnetic forces generated between the plurality of fixed part magnets and the plurality of magnetic attracting bodies.

[0018] A ninth aspect of the present invention is directed to a motion compensation device according to any one of the first to eighth aspects, wherein the movable part magnet is preferably disposed in a recess provided in the movable member.

[0019] A tenth aspect of the present invention relates to a motion compensation device according to the ninth aspect, wherein the recess in which the movable-part magnet is disposed is preferably covered with a member different from the movable part.

[0020] In the image stabilization device according to an eleventh aspect of the present invention, in any one of the first to eighth aspects, it is preferable that the movable part magnet is arranged in a frame portion provided on the movable member, the frame portion on which the movable part magnet is arranged is covered by a member different from the movable member, and the movable part magnet arranged on the frame portion faces the fixed member in an exposed state.

[0021] A twelfth aspect of the present invention is directed to the image stabilizer of the tenth or eleventh aspect, wherein the different member is preferably made of a magnetic material.

[0022] A thirteenth aspect of the present invention is directed to a motion compensation device according to any one of the tenth to twelfth aspects, wherein the different member is preferably fixed to the movable member by at least one of a screw and an adhesive.

[0023] A fourteenth aspect of the present invention is directed to a motion compensation device according to any one of the first to thirteenth aspects, wherein the movable member is preferably a resin molded product molded from resin.

[0024] A fifteenth aspect of the invention is a blur correction device that has a fixed part having a fixed member including a magnetic material, a movable part that holds an image sensor and is configured to be movable relative to the fixed part within a plane that intersects the optical axis, and a magnetic drive part that moves the movable part within the plane, and that performs blur correction by movement of the movable part within the plane, wherein the blur correction device is provided with a movable part magnet arranged on the movable part, and the movable part magnet is arranged on the movable part that corresponds to a different side or corner of the image sensor with respect to the position of the magnetic drive part.

[0025] A sixteenth aspect of the invention is an imaging device including the image stabilization device according to any one of the first to sixteenth aspects. [Brief description of the drawings]

[0026] [Figure 1] FIG. 1 is a front perspective view showing an embodiment of a motion compensation device. [Diagram 2] FIG. 2 is a rear perspective view showing an embodiment of the image stabilization device. [Diagram 3] FIG. 3 is an exploded perspective view of the image stabilization device. [Figure 4] FIG. 4 is an exploded perspective view of a fixing portion of the image stabilization device. [Diagram 5] FIG. 5 is a perspective view of a fixing portion of the image stabilization device. [Figure 6] FIG. 6 is a front view of the movable portion of the image stabilization device. [Figure 7] FIG. 7 is a front perspective view of the movable portion of the image stabilization device. [Figure 8] FIG. 8 is a front view of a flexible printed circuit board on which the coil and other components that constitute the VCM are mounted. [Figure 9] FIG. 9 is a rear view of a flexible printed circuit board on which the coils and other components that constitute the VCM are mounted. [Figure 10]FIG. 10 is a rear view of the movable portion of the image stabilization device. [Figure 11] FIG. 11 is a rear perspective view of the movable portion of the image stabilization device. [Figure 12] FIG. 12 is a cross-sectional view of the main parts of the movable members including the ball holding portion of the image stabilization device. [Figure 13] FIG. 13 is a cross-sectional view of the VCM. [Figure 14] FIG. 14 is a cross-sectional view of a main part of a movable member and the like showing a first embodiment of a mounting structure for a movable part magnet. [Figure 15] FIG. 15 is a front view of the movable portion of the image stabilization device. [Figure 16] FIG. 16 is a graph showing an example of the relationship between sensitivity and assembly variations due to the material used for the movable magnet. [Figure 17] FIG. 17 is a diagram showing the positional relationship between the movable magnet and components of the magnetic circuit. [Figure 18] FIG. 18 is a cross-sectional view of a main portion of a movable member and the like, showing a second embodiment of a mounting structure for a movable-part magnet. [Figure 19] FIG. 19 is a cross-sectional view of a main part of a movable member and the like, showing a third embodiment of a mounting structure for a movable-part magnet. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a motion compensation device and an imaging device according to the present invention will now be described in detail with reference to the accompanying drawings.

[0028] [Imaging device] The imaging device according to the present invention is, for example, a mirrorless digital camera with interchangeable lenses, and includes a shake correction device having an IBIS function.

[0029] An interchangeable lens mirrorless digital camera is a digital camera that allows you to attach interchangeable lenses to the camera body. The lens (interchangeable lens) is attached to the camera body via a mount so that it can be freely attached and detached.

[0030] In-body image stabilization is a classification of image stabilization, where the mechanism for image stabilization is built into the camera body, not into the lens. Image sensor shift type image stabilization devices with IBIS function are used. Image sensor shift type image stabilization devices move the image sensor (image sensor) to reduce image blur caused by camera shake.

[0031] In recent years, there has been a demand for even smaller camera bodies in interchangeable lens digital cameras, which has resulted in a demand for smaller image stabilization devices as well.

[0032] The following describes a compact image stabilization device according to the present invention.

[0033] [Image blur correction device] 1 and 2 are front and rear perspective views showing an embodiment of a motion compensation device.

[0034] The image stabilization device 1 shown in Fig. 1 is a image stabilization device with an IBIS function, and is used in a mirrorless single-lens camera, for example. A mirrorless single-lens camera is a classification of digital cameras, and is a general term for digital cameras in which the image is viewed through an electronic view finder (EVF) or a rear monitor, instead of the optical viewfinder used in single-lens reflex cameras.

[0035] The image stabilization device 1 corrects camera shake by moving the image sensor 30, which is an image sensor, within a plane that intersects with the optical axis Zs. The plane that intersects with the optical axis Zs is a plane that is substantially perpendicular to the optical axis Zs, and includes a plane that is nearly perpendicular to the optical axis Zs.

[0036] For the imaging element 30, the axis that passes through a predetermined reference point Os and is perpendicular to the light receiving surface is defined as the "optical axis Zs of the imaging element." In this embodiment, the center of the light receiving surface (imaging area) is defined as the reference point Os. Therefore, in this embodiment, the axis that passes through the center of the light receiving surface and is perpendicular to the light receiving surface is the optical axis Zs of the imaging element. The center of the light receiving surface includes a range that is substantially recognized as the center (including so-called almost the center). In addition, the axis perpendicular to the light receiving surface includes a range that is substantially recognized as perpendicular (including so-called almost perpendicular).

[0037] As described later, in this embodiment, camera shake is corrected by shifting and / or rotating the imaging element 30 within a plane perpendicular (including substantially perpendicular) to the optical axis Zs.

[0038] The image sensor 30 has a substantially rectangular shape on a projection plane that intersects with the optical axis Zs. The direction of the long side of the substantially rectangular image sensor 30 is defined as the x direction, the direction of the short side as the y direction, and the direction of the optical axis Zs as the z direction. The origin of the xyz three-axis Cartesian coordinate system can be set to the reference point Os, which is the center of the light receiving surface of the image sensor 30.

[0039] The shift of the imaging element 30 means to move the imaging element 30 in the x direction and / or y direction, and the rotation means to rotate the imaging element 30 around the optical axis.

[0040] The image stabilization device 1 is attached to a body frame (body chassis) of the camera body (not shown) and disposed inside the camera body. In the image stabilization device 1 attached to the body frame, the light receiving surface of the image sensor is disposed on the optical axis of the lens (interchangeable lens) attached to the camera body. In addition, in the image stabilization device 1 attached to the body frame, the light receiving surface of the image sensor 30 is disposed perpendicular (including nearly perpendicular) to the optical axis of the lens attached to the camera body. In other words, the image stabilization device 1 is attached to the body frame so that the optical axis Zs of the image sensor 30 coincides (including nearly coincides) with the optical axis of the lens attached to the camera body.

[0041] The image sensor 30 has an origin position where the reference point Os is located on the optical axis of the lens attached to the camera body, and its position is controlled based on the origin position. When the image sensor 30 is located at the origin position, its optical axis Zs is coaxial with the optical axis of the lens attached to the camera body.

[0042] It should be noted that the image stabilization device 1 can be turned on and off as desired. When the image stabilization function is turned off, the image sensor 30 is held at the origin position. Specifically, the image stabilization device 1 is controlled so that the image sensor 30 is held at the origin position.

[0043] There is no particular limitation on the type of the imaging element 30. As an example, in the present embodiment, a CMOS (Complementary Metal Oxide Semiconductor) imaging element is used. Alternatively, a CCD (Charge Coupled Device) imaging element or the like may be used as the imaging element.

[0044] FIG. 3 is an exploded perspective view of the image stabilization device.

[0045] 3, image stabilization device 1 has a fixed part 10 and a movable part 20. Fixed part 10 is a part that is fixed to a camera body when image stabilization device 1 is attached to the camera body. Fixed part 10 has fixed member 11 and front yoke 12 attached to fixed member 11, and functions as a holder for movable part 20.

[0046] Movable part 20 is a part that moves relative to the camera body (i.e., fixed part 10) when image stabilizer 1 is attached to the camera body. Movable part 20 has a movable member 21 that holds image sensor 30, and is configured to be movable within a plane that intersects with optical axis Zs.

[0047] The fixed member 11 includes a magnetic material such as iron, and functions as a rear yoke and a magnetic attracting body. The movable member 21 is made of a non-magnetic material.

[0048] <Fixed part> FIG. 4 is an exploded perspective view of a fixing portion of the motion compensation device, and FIG. 5 is a perspective view of the fixing portion of the motion compensation device.

[0049] As shown in FIGS. 4 and 5, the fixed portion 10 includes a fixed member 11 that serves as a base of the fixed portion 10, and a front yoke 12.

[0050] Both the fixed member 11 and the front yoke 12 have a plate-like shape. The fixed member 11 and the front yoke 12 are integrated by fastening the front yoke 12 to three support pillars 13 extending from the fixed member 11 with screws 14. The three support pillars 13 function as spacers. The fixed member 11 and the front yoke 12 integrated via the three support pillars 13 are arranged parallel to each other at a predetermined interval in the front-rear direction (z direction).

[0051] As described above, the fixed member 11 includes a magnetic material, and functions as a rear yoke and a magnetic attraction body.

[0052] Front yoke 12 is provided with mounting portions 12A for mounting image stabilization device 1 to the body frame of the camera body. Mounting portions 12A are provided at a plurality of locations on front yoke 12. Each mounting portion 12A is provided with a screw hole 12A1. Image stabilization device 1 is assembled to the camera body by screwing each mounting portion 12A to the body frame of the camera body.

[0053] In addition, multiple voice coil motors (VCMs) including multiple coils arranged in the movable member 21 and multiple fixed part magnets arranged in the fixed member 11 are used as magnetic driving parts that drive the movable part 20.

[0054] That is, as shown in FIG. 4, fixed member 11 is fitted with a pair of Y-axis magnets 41a, 41b constituting a Y-axis VCM that drives movable part 20 in the y direction, and a pair of first X-axis magnets 51a, 51b and a pair of second X-axis magnets 61a, 61b that respectively constitute a first X-axis VCM and a second X-axis VCM that drive movable part 20 in the x direction.

[0055] The pair of Y-axis magnets 41a, 41b are arranged in parallel in the y direction. The pair of Y-axis magnets 41a, 41b are fixed to the fixing member 11 by, for example, an adhesive.

[0056] Similarly, the pair of first X-axis magnets 51a, 51b and the pair of second X-axis magnets 61a, 61b are arranged in parallel in the x-direction, and the first X-axis magnets 51a, 51b and the second X-axis magnets 61a, 61b are arranged spaced apart in the y-direction. The pair of first X-axis magnets 51a, 51b and the pair of second X-axis magnets 61a, 61b are fixed to the fixing member 11 by, for example, an adhesive.

[0057] Furthermore, a pair of Y-axis position detection magnets 45a, 45b are attached to the fixed member 11. The pair of Y-axis position detection magnets 45a, 45b are arranged in parallel at a fixed interval in the y direction and are fixed to the fixed member 11 by, for example, an adhesive.

[0058] 4 and 5, two 11B are movable range restriction holes into which two stopper pins 22 (see FIG. 10) provided on the back surface of the movable member 21 are inserted. When the stopper pins 22 come into contact with the movable range restriction holes 11B, the movable portion 20 (movable member 21) is The range of movement is limited.

[0059] <Movable part> Fig. 6 is a front view of the movable part of the image stabilization device, mainly showing the members that hold the movable part, and Fig. 7 is a perspective view of the movable part, showing the members that hold the movable part and the magnetic member arranged in the movable part, as viewed from the front side.

[0060] As shown in FIGS. 6 and 7, the movable part 20 has a movable member 21 which serves as a base of the movable part 20.

[0061] The movable member 21 has an imaging element holding portion 21A, a flange portion 21B, and a movable-part magnet 80. As an example, in the present embodiment, the movable member 21 is made of a resin molded product. That is, it is produced by processing a resin such as plastic by a processing method such as injection molding.

[0062] The imaging element holding portion 21A is a holding portion that holds the imaging element 30 (see FIG. 1).

[0063] The imaging element holding portion 21A has a rectangular frame shape with a portion cut out. The inner periphery (opening) of the imaging element holding portion 21A has a shape corresponding to the shape of the outer periphery of the imaging element 30. The imaging element 30 is attached from the side of the imaging element holding portion 21A by utilizing the cut out portion, and is held in the inner periphery of the imaging element holding portion 21A. As an example, in this embodiment, the imaging element 30 is adhered to the inner periphery of the imaging element holding portion 21A with an adhesive and held therein. After the imaging element 30 is attached, a strip-shaped light-shielding sheet 32 ​​(see FIG. 1) having light-shielding properties is attached to the cut out portion of the imaging element holding portion 21A.

[0064] The flange portion 21B has a plate-like shape and is provided so as to protrude like a brim from the outer periphery of the imaging element holding portion 21A. In the present embodiment, as shown in Fig. 6, the flange portion 21B is provided so as to protrude upward and to the left side of the imaging element holding portion 21A in a front view.

[0065] The coils, balls, etc. that constitute the VCM are disposed on the flange portion 21B.

[0066] In FIG. 6, the flange portion 21B is formed with a Y-axis coil holding portion 23Y in which the Y-axis coil 42 is arranged, and a first X-axis coil holding portion 23X1 and a second X-axis coil holding portion 23X2 in which the first X-axis coil 52 and the second X-axis coil 62 are arranged, respectively.

[0067] FIG. 8 is a front view of a flexible printed circuit board on which the coils and other components that constitute the VCM are mounted, and FIG. 9 is a rear view of the flexible printed circuit board.

[0068] 9, the Y-axis coil 42, the first X-axis coil 52, and the second X-axis coil 62 are mounted on the back side of the flexible printed circuit board 70. Furthermore, a first X-axis Hall sensor 53 and a first X-axis thermistor 54 are mounted on the inner side of the first X-axis coil 52 of the flexible printed circuit board 70, and similarly, a second X-axis Hall sensor 63 and a second X-axis thermistor 64 are mounted on the inner side of the second X-axis coil 62 of the flexible printed circuit board 70.

[0069] On the other hand, as shown in FIG. 8, a plurality of magnetically attracted members 71Ya, 71Yb, 71X1, and 71X2 are attached to the front side of the flexible printed circuit board 70 via a non-magnetic reinforcing member 210. As shown in FIG.

[0070] Furthermore, the flexible printed circuit board 70 is formed with a round hole 233 and long holes 231 and 235 for positioning.

[0071] The flexible printed circuit board 70 shown in FIG. 8 and the like is disposed and fixed to the flange portion 21B of the movable member 21 shown in FIG.

[0072] That is, the flexible printed circuit board 70 is positioned relative to the movable member 21 by inserting the three bosses 232, 234, and 246 formed on the flange portion 21B of the movable member 21 into the long hole 231, the round hole 233, and the long hole 235 formed in the flexible printed circuit board 70, respectively.

[0073] At this time, the Y-axis coil 42, the first X-axis coil 52, and the second X-axis coil 62 mounted on the flexible printed circuit board 70 are arranged in the Y-axis coil holding portion 23Y, the first X-axis coil holding portion 23X1, and the second X-axis coil holding portion 23X2 formed on the flange portion 21B of the movable member 21.

[0074] After the flexible printed circuit board 70 is positioned on the flange portion 21B of the movable member 21, adhesive is filled into gaps between the inner circumferential surfaces of the Y-axis coil holding portion 23Y, the first X-axis coil holding portion 23X1, and the second X-axis coil holding portion 23X2 and the outer circumferential surfaces of the Y-axis coil 42, the first X-axis coil 52, and the second X-axis coil 62, and the adhesive is solidified to fix the Y-axis coil 42, the first X-axis coil 52, and the second X-axis coil 62 to the movable member 21. In addition, adhesive is applied to appropriate positions between the flexible printed circuit board 70 and the flange portion 21B of the movable member 21, to fix the flexible printed circuit board 70 to the flange portion 21B of the movable member 21. It is preferable to use an ultraviolet-curing adhesive as the adhesive. This is because the adhesive can be solidified in a short time by irradiating ultraviolet rays after filling and applying the adhesive.

[0075] The magnetic attraction bodies 71Ya, 71Yb, the magnetic attraction body 71X1, and the magnetic attraction body 71X2 are configured as part of the magnetic attraction force that magnetically biases the movable part 20 to the fixed part 10 by the z-direction magnetic force generated between a pair of Y-axis magnets 41a, 41b, a pair of first X-axis magnets 51a, 51b, and a pair of second X-axis magnets 61a, 61b, which are fixed part magnets attached to the fixed member 11 that constitutes the VCM.

[0076] FIG. 10 is a rear view of the movable portion of the motion compensation device, and FIG. 11 is a rear perspective view of the movable portion of the motion compensation device.

[0077] As shown in Figures 10 and 11, flange portion 21B of movable member 21 constituting movable section 20 is formed with three ball retaining portions 33a, 33b, and 33c that respectively house and retain three balls (rolling elements) 31a, 31b, and 31c.

[0078] The ball holding portions 33a, 33b, and 33c are holding portions for the balls 31a, 31b, and 31c on the movable portion side. The ball holding portions 33a, 33b, and 33c are configured with rectangular recesses. The balls 31a, 31b, and 31c are accommodated in the ball holding portions 33a, 33b, and 33c and are held by the movable member 21. A metal plate 34 is disposed on the bottom of the ball holding portions 33a, 33b, and 33c.

[0079] In FIG. 11, three reference numerals 11A denote ball contact portions that are installed on the fixed member 11 and that come into contact with the three balls 31a, 31b, and 31c (see FIGS. 4 and 5).

[0080] FIG. 12 is a cross-sectional view of the main parts of the movable member including the ball holding portion of the image stabilization device, and in particular, is a cross-sectional view of the movable member including the ball holding portion shown on the right side of FIG.

[0081] 12, a ball contact portion 11A is provided on a fixed member 11. The ball contact portion 11A functions as a rolling surface for balls 31a, 31b, and 31c on the fixed portion 10 side.

[0082] On the other hand, a plate 34 disposed at the bottom of ball holding portions 33a, 33b, and 33c formed on the movable member 21 functions as a rolling surface for the balls 31a, 31b, and 31c on the movable portion 20 side.

[0083] The three balls 31a, 31b, 31c housed in three ball holding portions 33a, 33b, 33c (ball holding portions 33a, 33b, 33c formed at the vertices of the triangle shown in Figure 10) formed on the movable member 21 allow the movable portion 20 to move within a plane perpendicular to the optical axis.

[0084] <Assembly of the image stabilization device> The image stabilization device 1 is assembled as follows.

[0085] 3, after the movable part 20 is attached to the fixed member 11, the front yoke 12 is fixed to the fixed member 11 with the screws 14. In this way, the movable part 20 is held by the fixed part 10.

[0086] When the movable part 20 is attached to the fixed member 11, the balls 31a, 31b, and 31c are accommodated in the ball holding portions 33a, 33b, and 33c, and the movable part 20 is attached to the fixed member 11. As a result, the balls 31a, 31b, and 31c are disposed between the movable part 20 (movable member 21) and the fixed member 11, and the movable part 20 is held movably via the balls 31a, 31b, and 31c.

[0087] Furthermore, when the movable part 20 is attached to the fixed member 11, it is attached so that the stopper pin 22 enters the movable range restriction hole 11B.

[0088] When the movable part 20 is attached to the fixed member 11, the movable part 20 is magnetically biased toward the fixed part 10 by the magnetic force generated between the magnetic attraction bodies 71Ya, 71Yb, 71X1, 71X2 provided on the movable part 20 and the fixed part magnets (Y-axis magnets 41a, 41b, first X-axis magnets 51a, 51b and second X-axis magnets 61a, 61b) of each VCM provided on the fixed member 11.

[0089] Moreover, the movable part 20 is magnetically biased toward the fixed part 10 by a magnetic force generated between the movable part magnet 80 arranged in the movable member 21 and the fixed member 11 including a magnetic body.

[0090] As a result, the movable part 20 is magnetically biased onto the fixed member 11 via the balls 31 and is held movably.

[0091] <Prevention of moving parts from falling off> The movable part 20 held by the fixed part 10 has the flange part 21B of the movable member 21 disposed between the fixed member 11 and the front yoke 12 with a predetermined gap therebetween. This restricts movement of the movable part 20 toward the optical axis, preventing the movable part 20 from falling off. For example, even if the movable member 21 is lifted off the fixed member 11 due to an impact or the like, the movable member 21 comes into contact with the front yoke 12 before the stopper pin 22 comes out of the movable range restriction hole 11B, preventing the movable part 20 from falling off.

[0092] <Magnetic drive unit> In this embodiment, the movable part 20 is driven by using a VCM as the magnetic drive part.

[0093] The image stabilization device 1 has, as magnetic drive units for the movable part 20, a Y-axis VCM 40 that drives the movable part 20 in the y-axis direction, and two X-axis VCMs 50, 60 that drive the movable part 20 in the x-axis direction.

[0094] One X-axis VCM 50 is referred to as the first X-axis VCM 50, and the other X-axis VCM 60 is referred to as the second X-axis VCM 60. The first X-axis VCM 50 and the second X-axis VCM 60 are arranged vertically in parallel with the optical axis in between in a plane perpendicular to the optical axis.

[0095] (1) Y-axis VCM The Y-axis VCM 40 has a pair of Y-axis magnets 41a, 41b, and a Y-axis coil 42. The Y-axis coil 42 is provided on the movable portion 20 side, and the pair of Y-axis magnets 41a, 41b are provided on the fixed portion 10 side (this is a so-called moving coil type VCM).

[0096] As shown in FIG. 4, a pair of Y-axis magnets 41a, 41b are provided on the fixed member 11. The pair of Y-axis magnets 41a, 41b are arranged in parallel in the vertical direction. The pair of Y-axis magnets 41a, 41b are fixed to the fixed member 11, for example, by being bonded with an adhesive. As described above, the fixed member 11 is made of a magnetic material (iron as an example) and functions as a rear yoke. The pair of Y-axis magnets 41a, 41b form a magnetic circuit between the fixed member 11, which functions as the rear yoke, and the front yoke 12. The Y-axis coil 42 is disposed in this magnetic circuit when the movable part 20 is assembled to the fixed part 10.

[0097] (2) 1st X-axis VCM The first X-axis VCM 50 is configured similarly to the Y-axis VCM 40, and has a pair of first X-axis magnets 51a, 51b, and a first X-axis coil 52. The first X-axis coil 52 is provided on the movable portion 20 side, and the pair of first X-axis magnets 51a, 51b is provided on the fixed portion 10 side.

[0098] As shown in FIG. 4, a pair of first X-axis magnets 51a, 51b are provided on the fixed member 11. The pair of first X-axis magnets 51a, 51b are arranged in parallel at a certain interval in the left-right direction (horizontal direction). The pair of first X-axis magnets 51a, 51b are fixed to the fixed member 11, for example, by bonding with an adhesive. The pair of first X-axis magnets 51a, 51b form a magnetic circuit between the fixed member 11, which functions as a rear yoke, and the front yoke 12. The first X-axis coil 52 is arranged in this magnetic circuit when the movable part 20 is assembled to the fixed part 10.

[0099] (3) 2nd X-axis VCM The second X-axis VCM 60 is configured similarly to the Y-axis VCM 40, and has a pair of second X-axis magnets 61a, 61b, and a second X-axis coil 62. The second X-axis coil 62 is provided on the movable unit 20 side, and the pair of second X-axis magnets 61a, 61b are provided on the fixed unit 10 side.

[0100] As shown in Fig. 4, the pair of second X-axis magnets 61a, 61b are provided on the fixed member 11. The pair of second X-axis magnets 61a, 61b are arranged in parallel at a certain interval in the left-right direction (horizontal direction). The pair of second X-axis magnets 61a, 61b are fixed to the fixed member 11, for example, by bonding with an adhesive. The pair of second X-axis magnets 61a, 61b form a magnetic circuit between the fixed member 11, which functions as a rear yoke, and the front yoke 12. The second X-axis coil 62 is arranged in this magnetic circuit when the movable part 20 is assembled to the fixed part 10.

[0101] The movable part 20 moves (shifts) in the y direction (up and down direction) in a plane perpendicular to the optical axis by driving the Y-axis VCM 40. Moreover, the movable part 20 moves (shifts) in the x direction (left and right direction) in a plane perpendicular to the optical axis by driving the first X-axis VCM 50 and the second X-axis VCM 60. Furthermore, the movable part 20 rotates (rolls) around the optical axis in response to changes in the movement position caused by the first X-axis VCM 50 and the second X-axis VCM 60.

[0102] FIG. 13 is a cross-sectional view of the VCM, particularly the first X-axis VCM.

[0103] The first X-axis VCM 50 shown in FIG. 13 is composed of a fixed member 11 functioning as a rear yoke, a front yoke 12, a pair of first X-axis magnets 51a, 51b provided on the fixed member 11, and a first X-axis coil 52 provided on the movable member 21.

[0104] After the first X-axis coil 52 is positioned, an adhesive is filled into the gap between the first X-axis coil holding portion 23X1 and the first X-axis coil 52, and the adhesive is hardened to fix the first X-axis coil 52 to the first X-axis coil holding portion 23X1.

[0105] According to the first X-axis VCM 50 configured as described above, a magnetic circuit is formed by the pair of first X-axis magnets 51a, 51b, the fixed member 11 functioning as the rear yoke, and the front yoke 12, and the first X-axis coil 52 is disposed within this magnetic circuit.

[0106] Therefore, by controlling the current flowing through the first X-axis coil 52, the position of the first X-axis coil 52 of the movable part 20 in the x direction can be controlled.

[0107] In addition, in FIG. 13, the magnetic attraction body 71X1 arranged on the non-magnetic reinforcing member 210 is attracted by a pair of first X-axis magnets 51a, 51b, and functions as part of the magnetic attraction force that magnetically biases the movable part 20 toward the fixed part 10.

[0108] In addition, the second X-axis VCM 60 is configured similarly to the first X-axis VCM 50, and by controlling the current flowing through the second X-axis coil 62 of the second X-axis VCM 60, the x-direction position of the second X-axis coil 62 of the movable part 20 can be controlled.

[0109] Furthermore, the Y-axis VCM 40 is configured similarly to the first X-axis VCM 50, and by controlling the current flowing through the Y-axis coil 42 of the Y-axis VCM 40, the position of the Y-axis coil 42 of the movable part 20 in the y direction can be controlled.

[0110] <Position detection section> The image stabilization device 1 has three position detection units as means for detecting the position (including rotation) of the movable part 20. Specifically, the image stabilization device 1 has a Y-axis position detection unit that detects the position of the Y-axis coil 42, a first X-axis position detection unit that detects the position of the first X-axis coil 52, and a second position detection unit that detects the position of the second X-axis coil 62.

[0111] (1) Y-axis position detector The Y-axis position detection unit detects the y-direction position of the Y-axis coil 42. The Y-axis position detection unit is mainly composed of a Y-axis Hall sensor 43, a Y-axis thermistor 44, and a pair of Y-axis position detection magnets 45a, 45b.

[0112] The Y-axis Hall sensor 43 and the Y-axis thermistor 44 are mounted on the imaging element substrate 30A as shown in FIG.

[0113] As shown in Fig. 4 etc., the pair of Y-axis position detection magnets 45a, 45b are provided on the fixed member 11. The pair of Y-axis position detection magnets 45a, 45b are arranged in parallel at a certain interval in the vertical direction. The pair of Y-axis position detection magnets 45a, 45b are fixed to the fixed member 11 by, for example, bonding with an adhesive.

[0114] The Y-axis Hall sensor 43 detects the position of the Y-axis coil 42 in the Y-axis direction by detecting a change in magnetic flux density in the magnetic field generated by the Y-axis position detection magnets 45a and 45b.

[0115] The Y-axis thermistor 44 detects the temperature in the vicinity of the Y-axis Hall sensor 43. The temperature detected by the Y-axis thermistor 44 is used for temperature compensation of the Y-axis Hall sensor 43.

[0116] (2) First X-axis position detector The first X-axis position detection unit detects the position of the first X-axis coil 52 in the X-axis direction. The first X-axis position detection unit is mainly composed of the first X-axis Hall sensor 53, the first X-axis thermistor 54, and the first X-axis magnets 51a, 51b. As described above, the first X-axis magnets 51a, 51b are fixed magnets that constitute the first X-axis VCM 50. That is, the first X-axis position detection unit detects the position of the first X-axis coil 52 in the X-axis direction by using the first X-axis magnets 51a, 51b that constitute the first X-axis VCM 50.

[0117] The first X-axis Hall sensor 53 and the first X-axis thermistor 54 are provided on the movable part 20 side. As shown in FIG. 9, in the present embodiment, the first X-axis Hall sensor 53 and the first X-axis thermistor 54 are mounted on a flexible printed circuit board 70 and disposed on the inner periphery of the first X-axis coil 52.

[0118] The first X-axis Hall sensor 53 detects the position of the first X-axis coil 52 in the x direction by detecting a change in the magnetic flux density in the magnetic field generated by the first X-axis magnets 51a and 51b.

[0119] The first X-axis thermistor 54 detects the temperature in the vicinity of the first X-axis Hall sensor 53. The temperature detected by the first X-axis thermistor 54 is used for temperature compensation of the first X-axis Hall sensor 53.

[0120] (3) Second X-axis position detector The second X-axis position detection unit detects the position of the second X-axis coil 62 in the X-axis direction. The second X-axis position detection unit is mainly composed of the second X-axis Hall sensor 63, the second X-axis thermistor 64, and the second X-axis magnets 61a, 61b. As described above, the second X-axis magnets 61a, 61b are fixed magnets that constitute the second X-axis VCM 60. That is, the second X-axis position detection unit detects the position of the second X-axis coil 62 in the X-axis direction by using the second X-axis magnets 61a, 61b that constitute the second X-axis VCM 60.

[0121] The second X-axis Hall sensor 63 and the second X-axis thermistor 64 are provided on the movable part 20 side. As shown in FIG. 9, in this embodiment, the second X-axis Hall sensor 63 and the second X-axis thermistor 64 are mounted on a flexible printed circuit board 70 and disposed on the inner periphery of the second X-axis coil 62.

[0122] The second X-axis Hall sensor 63 detects the position of the second X-axis coil 62 in the x direction by detecting a change in the magnetic flux density in the magnetic field generated by the second X-axis magnets 61a and 61b.

[0123] The second X-axis thermistor 64 detects the temperature in the vicinity of the second X-axis Hall sensor 63. The temperature detected by the second X-axis thermistor 64 is used for temperature compensation of the second X-axis Hall sensor 63.

[0124] <Magnetic energization of moving parts> 6 and 7, the movable part magnet holding portion 21C provided on the movable member 21 is configured as a rectangular recess. The movable part magnet 80 is placed on this movable part magnet holding portion 21C and fixed with an adhesive.

[0125] Fig. 14 is a cross-sectional view of the main parts of the movable member etc. showing a first embodiment of the mounting structure for the movable part magnet, and is a cross-sectional view taken along line 14-14 in Fig. 6. Note that the movable part magnet 80 is not housed in the movable part magnet holding part 21C of the movable member 21 shown in Fig. 6, but the cross-sectional view shown in Fig. 14 shows a state in which the movable part magnet 80 is housed and fixed in the movable part magnet holding part 21C.

[0126] 14, the movable part magnet holding portion 21C of the movable member 21 is formed as a recess that accommodates the movable part magnet 80. The movable part magnet 80 is accommodated in the movable part magnet holding portion 21C, and adhesive 81 is filled in the gap between the side surface of the movable part magnet 80 and the side surface of the movable part magnet holding portion 21C and allowed to harden, thereby fixing the movable part magnet 80 to the movable member 21 (movable part magnet holding portion 21C).

[0127] The bottom of movable-part magnet holder 21C, which houses movable-part magnet 80, faces fixed member 11 via gap G. Since fixed member 11 is made of a magnetic material, movable-part magnet 80 magnetically biases movable member 21 (movable part 20) toward fixed member 11 (fixed part 10) by a magnetic force in the z direction generated between movable-part magnet 80 and fixed member 11.

[0128] FIG. 15 is a front view of the movable portion of the image stabilization device.

[0129] As shown in FIGS. 15 and 8, four magnetic attraction members 71Ya, 71Yb, 71X1, and 71X2 are attached to the flexible printed circuit board 70 fixed to the movable member 21 via a non-magnetic reinforcing member 210.

[0130] The magnetic attraction bodies 71Ya, 71Yb magnetically bias the movable member 21 (movable part 20) toward the fixed member 11 (fixed part 10) by a magnetic force in the z direction generated between them and a pair of Y-axis magnets 41a, 41b (see Figure 4) attached to the fixed member 11 that constitutes the Y-axis VCM 40.

[0131] Similarly, the magnetic attraction body 71X1 magnetically biases the movable part 20 toward the fixed part 10 by a magnetic force in the z direction generated between a pair of first X-axis magnets 51a, 51b as shown in FIG. 13, and the magnetic attraction body 71X2 magnetically biases the movable part 20 toward the fixed part 10 by a magnetic force in the z direction generated between a pair of second X-axis magnets 61a, 61b.

[0132] 15, the rectangular imaging element 30 has a first side and a second side opposite to the first side. If the top side of the imaging element 30 in FIG. 15 is the first side, the second side is the bottom side of the imaging element 30.

[0133] In this case, the position corresponding to the upper side, which is the first side, of the imaging element 30 corresponds to the magnetic drive unit (Y-axis VCM 40). The movable unit 20 is biased downward in the plane of the drawing in FIG. 15 by the magnetic attraction forces of the magnetic attraction bodies 71Ya, 71Yb, etc., at the positions corresponding to the upper side.

[0134] On the other hand, a movable part magnet 80 is arranged at a position corresponding to the bottom side, which is the second side, of the imaging element 30, and the movable part 20 is biased downward on the surface of the paper in Figure 15 by the magnetic attraction force of the movable part magnet 80, etc.

[0135] 15, if the left side of the imaging element 30 is the first side, then the right side of the imaging element 30 is the second side.

[0136] In this case, the position corresponding to the left side, which is the first side, of the imaging element 30 corresponds to the magnetic drive unit (first X-axis VCM50, second X-axis VCM60). The movable unit 20 is biased downward on the paper in FIG. 15 by the magnetic attraction force of the magnetic attraction bodies 71X1, 71X2, etc., at the positions corresponding to the left side.

[0137] On the other hand, a movable part magnet 80 is arranged at a position corresponding to the right side, which is the second side, of the imaging element 30, and the movable part 20 is biased downward on the surface of the paper in Figure 15 by the magnetic attraction force of the movable part magnet 80, etc.

[0138] 15, if the upper left corner of the imaging element 30 is defined as a first corner, then the second corner opposite to the first corner is the lower right corner of the imaging element 30.

[0139] In this case, the first corner of the imaging element 30 is at a position corresponding to the magnetic drive unit (magnetic attraction body 71Ya of Y-axis VCM40, first X-axis VCM50), and the movable part 20 is biased downward on the paper surface in Figure 15 by the magnetic attraction force of magnetic attraction body 71Ya at a position corresponding to the first corner, and magnetic attraction bodies 71X1, 71X2, etc.

[0140] On the other hand, a movable part magnet 80 is arranged at a position corresponding to the second corner of the imaging element 30, and the movable part 20 is biased downward on the surface of the paper in Figure 15 by the magnetic attraction force of the movable part magnet 80, etc.

[0141] The biasing force (magnetic attraction force) by each movable part magnet and magnetic attraction body is a force in the z direction (optical axis direction) that presses movable part 20, on which image sensor 30 is mounted, against fixed part 10. By distributing and receiving the biasing force at three points by balls 31a, 31b, and 31c, fluttering in the z direction of movable part 20 while image stabilizer 1 is in operation is eliminated, and by eliminating blurring of the optical distance from the lens to the image plane of image sensor 30, stable, high-quality photography is made possible.

[0142] In each ball section, the plate 34, which is the ball receiving surface of the movable section 20, the balls 31a, 31b, and 31c, and the ball abutment section 11A, which is the ball receiving surface of the fixed section 10, form a sandwich structure (see FIG. 12). In this case, the urging force acting on the movable section 20 is transmitted to the balls 31a, 31b, and 31c through the ball receiving surface. Because both the balls and the ball receiving surface are sufficiently smooth, the frictional force is small enough to be ignored, and the force acting on the balls 31a, 31b, and 31c is dominated by the z-direction urging force component. The balls 31a, 31b, and 31c are merely sandwiched between the two ball receiving surfaces. If there is no force transmitted from the balls 31a, 31b, and 31c to the ball receiving surface of the movable section 20, the movable section 20 will float from the balls and tilt rather than perpendicular to the optical axis (hereinafter, this phenomenon will be referred to as the "tilt" of the movable section 20). Whether or not this tilt has occurred can be determined by calculating the difference between the moment around an axis that includes a line segment with the two balls as vertices and a reference value (tilt moment).

[0143] Now, in FIG. 15, if the line segment connecting ball 31a and ball 31b is the A-axis, the line segment connecting ball 31b and ball 31c is the B-axis, and the line segment connecting ball 31c and ball 31a is the C-axis, and the directions of the tilt moment indicated by the arrows of the A-axis, B-axis, and C-axis (the directions in which the balls opposed to the A-axis, B-axis, and C-axis are pressed down) are positive, the relationship between the tilt moment around each axis and the tilt (result) is as shown in the following [Table 1].

[0144] [Table 1]

[0145] When the tilt moments around the A-axis, B-axis, and C-axis are all positive (Case 1 above), the three balls 31a, 31b, and 31c do not move away from the ball abutment portion 11A or the plate 34, but always abut against it.

[0146] In order to prevent the movable part 20 from “tilting”, it is necessary to design it so that the center of the resultant force (moment center of gravity) of the tilt moments around each axis is located within the triangle formed by the A-axis, B-axis, and C-axis (hereinafter referred to as the “ball triangle”).

[0147] In the present invention, Y-axis magnets 41a, 41b, first X-axis magnets 51a, 51b, and second X-axis magnets 61a, 61b of Y-axis VCM 40, first X-axis VCM 50, and second X-axis VCM 60, which are magnetic drive units, are utilized, and magnetic attraction bodies 71Ya, 71Yb, 71X1, and 71X2 are provided at positions on the movable unit 20 side facing these Y-axis magnets 41a, 41b, first X-axis magnets 51a, 51b, and second X-axis magnets 61a, 61b, thereby constituting part of the magnetic attraction force.

[0148] In the case of only the magnetic attraction force using the magnet of the magnetic drive unit, the tilt moment around the B-axis and C-axis becomes negative, causing the movable part 20 to tilt (the ball floats up).

[0149] Therefore, in the present invention, the movable part magnet 80 is disposed at an appropriate position on the movable part 20 (movable member 21) so that tilting around the B-axis and C-axis does not occur (so as to achieve case 1 in [Table 1]). The position where the movable part magnet 80 is disposed is the position explained using FIG. 15 and the like as described above, which realizes the miniaturization of the movable part 20 (movable member 21) and does not affect the imaging element 30.

[0150] By utilizing the magnetic force of the magnetic drive unit as the magnetic attraction force, a special mechanical structure is not required, and there is no need to secure installation space for a magnetic spring, which has the advantage of allowing efficient use of space.

[0151] Further, the movable member 21 in the vicinity of the movable-part magnet 80 (movable-part magnet holding portion 21C) is not provided with the flange portion 21B, and the movable-part magnet 80 is disposed adjacent to the imaging element 30.

[0152] Furthermore, in this embodiment, the position where the movable part magnet 80 is arranged is the lower right corner of the movable member 21 when viewed from the front (the light receiving surface side of the image sensor 30) (see Figs. 6, 7, and 15). The position of the movable part magnet 80 is outside the ball triangle and is as far away as possible from the line segment (A axis) connecting the balls 31a and 31b.

[0153] Furthermore, the position of the magnetic spring including magnetic attraction body 71X2 is a position outside the line segment (B axis) connecting ball 31b and ball 31c, and the position of the magnetic spring including magnetic attraction bodies 71Ya, 71Yb, and 71X1 is a position outside the line segment (C axis) connecting ball 31c and ball 31a.

[0154] Furthermore, if the ball triangle is made smaller in order to miniaturize the movable part 20 (movable member 21), the center of the tipping moment is more likely to move outside the ball triangle due to fluctuations in the tipping moment, making it easier for the movable part 20 to tip during IBIS control; however, the ball triangle in this example is made as large as possible relative to the movable member 21.

[0155] <Function of the Movable Magnet in the Above-described Embodiment> (1) In order to reduce the in-plane position dependency of the tilt moment value, it is desirable to place the biasing force components of the movable part magnet 80 as far away as possible from all of the A to C axes. The moment has a magnitude of distance x force, and the moment fluctuates when the distance from the A to C axes changes depending on the in-plane position of the movable part 20. In order to make this moment fluctuation smaller than the moment fluctuation (10 to 20%) due to assembly variations, it is better to place the magnet 80 about 5 to 10 times the amount of movement from each axis in order to maximize the tilt moment and reduce the in-plane variation of the moment.

[0156] (2) The movable-part magnet 80 is disposed so that at least a portion of it overlaps with the imaging element 30 when viewed from the optical axis direction. Moreover, the movable-part magnet 80 is preferably disposed in a position that does not overlap with the pixel range (effective pixel area) 30B of the imaging element 30 when viewed from the optical axis direction. This is to suppress the influence of the movable-part magnet 80 on the imaging element 30 and the imaging element substrate 30A.

[0157] (3) The movable part magnet 80 is preferably arranged so as to be housed in the movable part magnet holding part 21C (recess) provided in the movable member 21 (see Figs. 7 and 14). This is because unless there is a mechanical restriction between the movable part magnet 80 and the movable part magnet holding part 21C, the movable part magnet 80 will attempt to approach the fixed part 10 further, and the magnetic attraction force will continue to grow stronger until it finally comes into contact with the fixed member 11.

[0158] Furthermore, in order to ensure that movable-part magnet 80 remains on the movable part 20 side even if the adhesive peels off due to the impact of dropping an imaging device equipped with image stabilization device 1, it is desirable for movable-part magnet holder 21C to hold the magnet in a shape with a depth greater than or equal to the thickness of movable-part magnet 80 (see FIG. 14). Movable member 21 including movable-part magnet holder 21C with such a complex and fine shape is desirably made of a resin molded product.

[0159] (4) As shown in Fig. 14, the thickness of the bottom of movable-part magnet holding portion 21C plus gap G is the distance between movable-part magnet 80 and fixed member 11 functioning as the rear yoke, and this distance determines the biasing force. Therefore, it is preferable to determine the magnet dimensions and material so that the biasing force does not vary significantly due to variations in assembly, parts, etc.

[0160] The magnetic force (F) has a characteristic that its magnitude is inversely proportional to the square of the gap distance (d) between the magnet and the magnetized body (F ∝ d -2 The biasing force increases as the gap distance (d) decreases due to the miniaturization of the movable part 20, and the magnitude of the biasing force varies depending on the in-plane position of the movable part 20 and the change in the gap distance (d) due to assembly variations.

[0161] In the present invention, the movable part magnet 80 is disposed on the movable part 21, and the movable part 21 (movable part 20) is magnetically biased to the fixed part 11 (fixed part 10) by the magnetic force generated between the movable part magnet 80 and the fixed part 11 functioning as a rear yoke, so that the magnetic force between the movable part magnet 80 and the fixed part 11 does not change even if the movable part 20 moves within a plane during IBIS control, and stable magnetic biasing can be performed. This is because the fixed part 11 facing the movable part magnet 80 is large enough to fully cover the movement range of the movable part magnet 80 that moves during IBIS control.

[0162] FIG. 16 is a graph showing an example of the relationship between sensitivity and assembly variations due to the material used for the movable magnet.

[0163] The solid line graph and the dashed line graph in FIG. 16 are both neodymium magnets, and are graphs showing the relationship between assembly variation and sensitivity for magnets made of different materials.

[0164] As shown in FIG. 16, the material corresponding to the solid line graph has a smaller change in sensitivity to assembly variations than the material corresponding to the dashed line graph, so it is preferable to use a magnet made of a material corresponding to the solid line graph.

[0165] (5) It is preferable that the movable magnet 80 be disposed in an independent position as far away as possible from the components of the magnetic circuit.

[0166] FIG. 17 is a diagram showing the positional relationship between the movable magnet and components of the magnetic circuit.

[0167] In FIG. 17, 90 indicates the area of ​​the magnetic drive parts (Y-axis VCM 40, first X-axis VCM 50, and second X-axis VCM 60) which are components of the magnetic circuit, and 92 indicates the area of ​​the Y-axis Hall sensor 43 and Y-axis position detection magnets 45a, 45b which are components of the magnetic circuit.

[0168] Placing the movable magnet 80 near the area 90 of the magnetic drive unit is undesirable because it strengthens the attraction or repulsion between the movable magnet 80 and the magnets of the VCM. Also, placing the movable magnet 80 near the area 92 of the Hall magnetic circuit creates an opposing force for the IBIS drive due to the in-plane magnetic force component near the Hall magnetic circuit, affecting controllability. Also, it reduces the Hall detection accuracy and degrades the IBIS performance.

[0169] Furthermore, by making the movable member 21 smaller, the components of the imaging device can be arranged closely in the lower left area 94 and the left side area 96 of the movable member 21 in FIG. 17, thereby making it possible to reduce the size of the entire imaging device.

[0170] (6) In addition to the flexible printed circuit board 70 that supplies current to the Y-axis coil 42, the first X-axis coil 52, and the second X-axis coil 62, the movable part 20 is provided with flexible printed circuit boards 72 and 74 including power lines and signal lines connected to the imaging element substrate 30A of the imaging element 30 as shown in Fig. 2. These flexible printed circuit boards 70, 72, and 74 pass through the gap between the movable member 21 and the fixed member 11 and are led out to the outside from an opening provided in the fixed member 11.

[0171] It is desirable that the movable part magnet 80 is located at the end of the movable member 21 in order to secure a space for the flexible printed circuit board 74 for the imaging element 30 and the heat dissipation structure. It is desirable that the movable member 21 corresponding to the back surface of the imaging element 30 is opened like a window in order to facilitate assembly when bonding the imaging element 30 to the movable member 21.

[0172] (7) It is desirable to arrange the movable magnet 80 so as not to cover the entire connector of the imaging element 30. It is preferable to expose about half of the connector lock to improve ease of assembly.

[0173] (8) It is desirable that the movable part magnet holder 21C that holds the movable part magnet 80 is located near the gate from the viewpoints of dimensional accuracy, mechanical strength, and moldability. It is also desirable to place it away from the weld to increase impact resistance.

[0174] (9) It is preferable to dispose the movable magnet 80 away from the flexible printed circuit board 74 for the imaging element 30. This is to reduce noise and enable high-quality imaging.

[0175] (10) It is desirable that the movable magnet 80 is located symmetrically around the optical axis with the magnetic attractor in the magnetic drive unit. This is because, since the biasing force of the magnetic attractor is larger than that of the movable magnet 80, it is possible to place a magnetic attractor that opposes the movable magnet 80 near the magnetic circuit where there is room to place a large magnetic attractor. In this case, the movable magnet 80 is placed so that the center of gravity of the biasing force by the magnetic attractor is as close to the center of the optical axis as possible.

[0176] <Modification of the mounting structure of the movable magnet> FIG. 18 is a cross-sectional view of a main portion of a movable member and the like, showing a second embodiment of a mounting structure for a movable-part magnet.

[0177] The second embodiment of the mounting structure for the movable part magnet shown in Figure 18 differs from the first embodiment shown in Figure 14 in that the recess of the movable part magnet holding portion 21C in which the movable part magnet 80 is arranged is covered by a member other than the movable member 21 (a plate-shaped or clip-shaped cover (hereinafter referred to as a "lid")) 82.

[0178] A portion of the lid 82 fits into the movable member 21, and is fixed to the movable member 21 by screws 84. The lid 82 may be fixed to the movable member 21 only by the screws 84, or may be fixed to the movable member 21 by an adhesive instead of the screws 84, or may be fixed to the movable member 21 by both the screws 84 and an adhesive.

[0179] By covering the opening of the recess of the movable part magnet holding portion 21C with the lid 82, it is possible to prevent the movable part magnet 80 from flying out of the movable part magnet holding portion 21C and colliding with the imaging element in the event of an impact, such as when the imaging device is dropped.

[0180] The lid 82 is not limited to being made of the same material (resin) as the movable member 21, and may be made of a magnetic metal (for example, iron). By making the lid 82 out of a magnetic metal, the lid 82 functions as a yoke on the imaging element side of the movable-part magnet 80, aligning the magnetic field and increasing the magnitude of the biasing force, and further, there is an advantage that the magnitude of the biasing force is less likely to fluctuate even if the movable part 20 moves in-plane.

[0181] FIG. 19 is a cross-sectional view of a main part of a movable member and the like, showing a third embodiment of a mounting structure for a movable-part magnet.

[0182] The third embodiment of the mounting structure for the movable part magnet 80 shown in Figure 19 differs from the bottomed movable part magnet holding portion 21C of the second embodiment etc. in that the movable part magnet holding portion 21C' of the movable member 21' is a bottomless frame portion.

[0183] In Figure 19, the movable part magnet 80 is placed on the movable part magnet holding part 21C' (frame part), and is fixed to the movable part magnet holding part 21C' by filling the gap between the movable part magnet 80 and the frame part with adhesive 86 and allowing it to solidify.

[0184] The method for fixing the lid 82 can be the same as in the second embodiment. Moreover, the lid 82 is preferably made of a magnetic metal.

[0185] According to the mounting structure of the movable part magnet 80 of the third embodiment, the movable part magnet holding part 21C' on which the movable part magnet 80 is arranged has no bottom (a mechanical restriction member between the movable part magnet 80 and the fixed member 11), and the lower surface of the movable part magnet 80 faces the fixed member 11 in an exposed state. This has the advantage that the position of the lower surface of the movable part magnet 80 can be easily adjusted.

[0186] [others] In the above embodiment, the image stabilization device according to the present invention is used in a digital camera with interchangeable lenses, but it goes without saying that the image stabilization device also includes a standalone image stabilization device.

[0187] Furthermore, the camera to which the image stabilization device according to the present invention is applied is not limited to a digital camera with interchangeable lenses, but can also be applied to other imaging devices such as video cameras, television cameras, and cine cameras.

[0188] Furthermore, the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0189] 1... Image stabilization device 10…Fixed part 11...Fixing member 11A…Ball contact part 11B…Movement range restriction hole 12…Front yoke 12A…Mounting part 12A1…hole 13...Strut 14…Screw 20...Movable part 21, 21'... Movable member 21A…Image sensor holding section 21B…Flange section 21C, 21C'...Movable part magnet holding part 22…Stopper pin 23X1…1st X-axis coil holding part 23X2…Second X-axis coil holding section 23Y…Y-axis coil holder 30...Image sensor 30A…Image sensor board 31a, 31b, 31c...Ball 32…Blackout sheet 33a, 33b, 33c...Ball holding section 34…Plate 40…Y-axis VCM 41a, 41b...Y-axis magnet 42…Y-axis coil 43…Y-axis Hall sensor 44…Y-axis thermistor 45a, 45b...Y-axis position detection magnet 50…1st X-axis VCM 51a, 51b...1st X-axis magnet 52…1st X-axis coil 53…1st X-axis Hall sensor 54…1st X-axis thermistor 60...2nd X-axis VCM 61a, 61b...2nd X-axis magnet 62…Second X-axis coil 63...2nd X-axis Hall sensor 64…2nd X-axis thermistor 70, 72, 74...Flexible printed circuit boards 71X1, 71X2, 71Ya, 71Yb...Magnetic adsorbent 80…Moving part magnet 81...Adhesive 82…Lid 84…Screw 86…Glue 92, 94, 96…area 210…Reinforcing member 231, 235…long hole 232, 234...Boss 233…Round hole G…Gap Os…Reference point Zs…Optical axis

Claims

1. A vibration reduction device having a fixed section having a fixed member including a magnetic substance, a movable section having a movable member that holds an image sensor and configured to be movable relative to the fixed section within a plane that intersects an optical axis, and a magnetic drive section that moves the movable section within the plane, the vibration reduction device performing vibration reduction by movement of the movable section within the plane, A movable part magnet is disposed on the movable member, The movable part is magnetically biased against the fixed part based on a magnetic force generated between the movable part magnet and the fixed member and a magnetic force generated at the position of the magnetic drive part. Image stabilization device.

2. The movable member is made of a non-magnetic material. The image stabilization device according to claim 1 .

3. the imaging element has a first side and a second side opposite to the first side, the first side is located opposite to the position of the magnetic drive unit, The movable part magnet is disposed on the movable member corresponding to a second side of the imaging element. The image stabilization device according to claim 1 .

4. the imaging element has a first corner and a second corner opposite the first corner; the first corner is a position opposite to a position of the magnetic drive unit, the movable part magnet is disposed on the movable member corresponding to the second corner of the imaging element; The image stabilization device according to claim 1 .

5. The movable part magnet is disposed on the movable member corresponding to a different side or corner of the imaging element with respect to the position of the magnetic driving part. The image stabilization device according to claim 1 .

6. The movable part magnet is disposed so that at least a portion of the movable part magnet overlaps with the imaging element when viewed from the optical axis direction. The image stabilization device according to claim 5 .

7. the movable part magnet is disposed at a position not overlapping with a pixel range of the imaging element when viewed from the optical axis direction; The image stabilization device according to claim 6.

8. the magnetic drive unit is composed of a plurality of voice coil motors including a plurality of coils arranged on the movable member and a plurality of fixed portion magnets arranged on the fixed member, the movable part includes a plurality of magnetic attraction bodies at positions facing the plurality of fixed part magnets, the movable part is magnetically biased to the fixed part by a magnetic force generated between the plurality of fixed part magnets and the plurality of magnetic attracting bodies; The image stabilization device according to claim 1 .

9. The movable part magnet is disposed in a recess provided in the movable member. The image stabilization device according to claim 1 .

10. The recess in which the movable part magnet is disposed is covered with a material different from the movable part. The image stabilization device according to claim 9.

11. The movable part magnet is disposed in a frame part provided on the movable member, the frame portion in which the movable part magnet is arranged is covered with a member different from the movable part, The movable part magnet arranged in the frame part faces the fixed member in an exposed state. The image stabilization device according to claim 1 .

12. The different members are made of magnetic materials. The image stabilization device according to claim 10 or 11.

13. The different member is fixed to the movable member by at least one of a screw and an adhesive. The image stabilization device according to claim 10 or 11.

14. The movable member is a resin molded product made of resin. The image stabilization device according to claim 1 .

15. A vibration reduction device having a fixed section having a fixed member including a magnetic substance, a movable section having a movable member that holds an image sensor and configured to be movable relative to the fixed section within a plane that intersects an optical axis, and a magnetic drive section that moves the movable section within the plane, the vibration reduction device performing vibration reduction by movement of the movable section within the plane, A movable part magnet is disposed on the movable member, The movable part magnet is disposed on the movable member corresponding to a different side or corner of the imaging element with respect to the position of the magnetic driving part. Image stabilization device.

16. A camera comprising the image stabilization device according to claim 1 or 15. Imaging device.

Images